Documents published in 2016 : Scipedia

Decision Support System Design Requirements, Information Management, and Urban Logistics Efficiency
W. Jaimes, J. Herrera, J. Gonzalez-Feliu, L. Palacios Argüello, J. Gonzalez-Feliu, L. Argüello, W. Adarme Jaimes, J. Parra Herrera

Collection of open chapters of books in transport research (2016). Vol. 2016, 20

Abstract
International audience; The task of feeding cities is a challenge that nowadays all governments face, which involves the coordination of multiple producers, distributors, logistics operators and traders of perishable foods. With the increasing population in cities, more food and better freight transport systems are required. This takes a particular importance in cities and urban zones, since the growing population needs to be fed, but freight transport is often seen as creating nuisances such as congestion or pollution, among others. In this context, several cities started to think on how improve the citys food supply system by combining proximity producers supply with advanced city logistics systems in order to decrease transport nuisances and improve the quality and sustainability of the food system.One of the possible actions is that of deploying proximity food hubs with a consequent urban food distribution system to supply the different urban zones of a city. However, this type of system is starting to be conceived and there is need of assessing the impacts of such alternative before thinking on its deployment possibilities. For this reason, this paper aims to propose a framework to assess different food delivery alternatives in the urban context focusing on a Food hub deployment and its impacts on urban development as a solution of urban consolidation center (UCC).The objective of this study is to enable municipalities to assess the consequences of food logistics flows centralization on an UCC-based food hub. Regarding the context of the research, the study focuses on a Food hub deployment to share the supplies for administrative restaurants of a city, following the sustainable food strategy of a French municipality. This municipality decided to show the example in terms of sustainable food supply and aims to increase the part of organic and local food for the administrative restaurants under its coordination. To do this, a specific food system needs to be conceived and assessed. To assess the suitability of such systems, it will be necessary to model both the demand and the logistics supply, to define the main indicators of sustainability and their estimation methods, then to construct the scenarios to assess and finally make the corresponding analyses. Document type: Part of book or chapter of book
Abstract
International audience; The task of feeding cities is a challenge that nowadays all governments face, which involves the coordination of multiple producers, distributors, [...]
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Tramp Ship Routing and Scheduling with Voyage Separation Requirements
C. Vilhelmsen, R. Lusby, J. Larsen

Collection of open chapters of books in transport research (2017). Vol. 2017, 22

Abstract
In this paper we explore tramp ship routing and scheduling. Tramp ships operate much like taxies following the available demand. Tramp operators can determine some of their demand in advance by entering into long-term contracts and then try to maximise profits from optional voyages found in the spot market. Routing and scheduling a tramp fleet to best utilise fleet capacity according to current demand is therefore an ongoing and complicated problem. Here we add further complexity to the routing and scheduling problem by incorporating voyage separation requirements that enforce a minimum time spread between some voyages. The incorporation of these separation requirements helps balance the conflicting objectives of maximising profit for the tramp operator and minimising inventory costs for the charterer, since these"br/"costs increase if similar voyages are not performed with some separation in time. We have developed a new and exact branch-and-price procedure for this problem. We use a dynamic programming algorithm to generate columns and describe a time window branching scheme used to enforce the voyage separation requirements which we relax in the master problem. Computational results show that our algorithm in general finds optimal solutions very quickly and performs much faster compared to an earlier a priori path generation method. Finally, we compare our method to an earlier adaptive large neighbourhood search heuristic and find that on similar-sized instances our approach generally uses less time to find the optimal solution than the adaptive large neighbourhood search method uses to find a heuristic solution. Document type: Book
Abstract
In this paper we explore tramp ship routing and scheduling. Tramp ships operate much like taxies following the available demand. Tramp operators can determine some of their [...]
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An effective video processing pipeline for crowd pattern analysis
H. Yu, Z. Xu, J. Wang, Y. Liu, J. Fan

Collection of open chapters of books in transport research (2017). Vol. 2017, 21

Abstract
With the purpose of automatic detection of crowd patterns including abrupt and abnormal changes, a novel approach for extracting motion textures from dynamic Spatio-Temporal Volume (STV) blocks formulated by live video streams has been proposed. This paper starts from introducing the common approach for STV construction and corresponding Spatio-Temporal Texture (STT) extraction techniques. Next the crowd motion information contained within the random STT slices are evaluated based on the information entropy theory to cull the static background and noises occupying most of the STV spaces. A preprocessing step using Gabor filtering for improving the STT sampling efficiency and motion fidelity has been devised and tested. The technique has been applied on benchmarking video databases for proof-of-concept and performance evaluation. Preliminary results have shown encouraging outcomes and promising potentials for its real-world crowd monitoring and control applications. Document type: Part of book or chapter of book
Abstract
With the purpose of automatic detection of crowd patterns including abrupt and abnormal changes, a novel approach for extracting motion textures from dynamic Spatio-Temporal [...]
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Rigorous Graphical Modelling of Movement in Collective Adaptive Systems
S. Gilmore, N. Zon, J. Hillston, J. Hillston, S. Gilmore, N. Zo?

Collection of open chapters of books in transport research (2016). Vol. 2016, 19

Abstract
Formal modelling provides valuable intellectual tools which can be applied to the problem of analysis and optimisation of systems. In this paper we present a novel software tool which provides a graphical approach to modelling of Collective Adaptive Systems (CAS) with constrained movement. The graphical description is translated into a model that can be analysed to understand the dynamic behaviour of the system. This generated model is expressed in CARMA, a modern feature-rich modelling language designed specifically for modelling CAS. We demonstrate the use of the software tool with an example scenario representing carpooling, in which travellers group together and share a car in order to reach a common destination. This can reduce their travel time and travel costs, whilst also ameliorating traffic congestion by reducing the number of vehicles on the road. Document type: Part of book or chapter of book
Abstract
Formal modelling provides valuable intellectual tools which can be applied to the problem of analysis and optimisation of systems. In this paper we present a novel software [...]
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Identifying the economic potential of indian districts
M. Roberts

Collection of open chapters of books in transport research (2016). Vol. 2016, 18

Abstract
Despite its rapid growth in recent decades, GDP per capita in India remains at a relatively low level by international standards, and the country continues to be marked by large subnational disparities in levels of well-being. These large disparities naturally lead to interest in Indias spatial landscape of potential for economic development. Against this backdrop, this paper presents the results of an analysis of underlying variations in economic potential across Indian districts, where economic potential is defined as the extent to which a district possesses factors that are important determinants of the ability to experience a high level of productivity. The analysis is based on a simple composite Economic Potential Index, which is constructed from variables for which robust evidence exists of their importance as determinants of local productivity. From the analysis, a picture emerges of a heterogeneous landscape of economic potential characterized by strong geographic clustering of districts. The paper also reveals particularly high levels of underperformance, relative to potential, for districts in Uttar Pradesh. Document type: Book
Abstract
Despite its rapid growth in recent decades, GDP per capita in India remains at a relatively low level by international standards, and the country continues to be marked by [...]
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Leveraging spatial abstraction in traffic analysis and forecasting with visual analytics
N. Andrienko, G. Andrienko, S. Rinzivillo

Collection of open chapters of books in transport research (2016). Vol. 2016, 17

Abstract
A spatially abstracted transportation network is a graph where nodes are territory compartments (areas in geographic space) and edges, or links, are abstract constructs, each link representing all possible paths between two neighboring areas. By applying visual analytics techniques to vehicle traffic data from different territories, we discovered that the traffic intensity (a.k.a. traffic flow or traffic flux) and the mean velocity are interrelated in a spatially abstracted transportation network in the same way as at the level of street segments. Moreover, these relationships are consistent across different levels of spatial abstraction of a physical transportation network. Graphical representations of the flux-velocity interdependencies for abstracted links have the same shape as the fundamental diagram of traffic flow through a physical street segment, which is known in transportation science. This key finding substantiates our approach to traffic analysis, forecasting, and simulation leveraging spatial abstraction.\\ud \\ud We propose a framework in which visual analytics supports three high-level tasks, assess, forecast, and develop options, in application to vehicle traffic. These tasks can be carried out in a coherent workflow, where each next task uses the results of the previous one(s). At the 'assess' stage, vehicle trajectories are used to build a spatially abstracted transportation network and compute the traffic intensities and mean velocities on the abstracted links by time intervals. The interdependencies between the two characteristics of the links are extracted and represented by formal models, which enable the second step of the workflow, 'forecast', involving simulation of vehicle movements under various conditions. The previously derived models allow not only prediction of normal traffic flows conforming to the regular daily and weekly patterns but also simulation of traffic in extraordinary cases, such as road closures, major public events, or mass evacuation due to a disaster. Interactive visual tools support preparation of simulations and analysis of their results. When the simulation forecasts problematic situations, such as major congestions and delays, the analyst proceeds to the step 'develop options' for trying various actions aimed at situation improvement and investigating their consequences. Action execution can be imitated by interactively modifying the input of the simulation model. Specific techniques support comparisons between results of simulating different "what if" scenarios. Document type: Part of book or chapter of book
Abstract
A spatially abstracted transportation network is a graph where nodes are territory compartments (areas in geographic space) and edges, or links, are abstract constructs, each [...]
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Achieving energy savings by intelligent transportation systems investments in the context of smart cities
A. Ardila-Gomez, G. Frame, A. Ardila-Gomez, Y. Chen, G. Frame, Y. Chen

Collection of open chapters of books in transport research (2016). Vol. 2016, 16

Abstract
Faced with the challenge of providing adequate transport services with limited resources, cities have, for several decades, been investing in Intelligent Transportation Systems (ITS). ITS utilize Information and Communications Technology (ICT) to make more efficient use of existing transport infrastructure with the aim of improving transport services and reducing congestion, accidents, and air pollution. In the past two decades, with the rapid advancement of ICT and intensive advocacy from big technology vendors, the concept of smart cities has gained great popularity and many cities have started to undertake a more holistic approach to improving urban services using technology in the name of smart city initiatives. Section two introduces these themes, which serve as the analytical framework to understand how smart mobility investments lead to energy savings. The comparison in the search for similarities among the case studies and interviews helped us develop a conceptual model, emphasizing cause and effect and presented in section three, of how ITS deployment and operation in the context of smart cities leads to energy saving benefits. This conceptual model is presented with detailed discussions of institutional, technological, and physical conditions at each step in the model. Section four focuses on energy savings with quantitative evidence of energy saving potential of ITS investments collected from literature and case studies. Section five links the results of this study to the Wuhan Integrated Transport Development Project and how the knowledge has been incorporated into project design. To further explore the energy efficiency potential of Wuhan and to mainstream ITS and smart transport solutions as a source of achieving energy efficiency using results of this study, a TRACE analysis was also completed as part of this research effort. This analysis focused on the passenger transport sector. Finally, policy recommendations on the major conditions under which ITS investments in the context of smart cities achieve energy savings are summarized in Section 6 with specific implications for cities in the developing countries. Document type: Book
Abstract
Faced with the challenge of providing adequate transport services with limited resources, cities have, for several decades, been investing in Intelligent Transportation Systems [...]
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Transit oriented development
A. McConville, B. Kober, C. Lane, J. Donham

Collection of open chapters of books in transport research (2016). Vol. 2016, 15

Abstract
Although urban development around transit stations doesnt lead to a direct financial contribution for the Transit Agency (or other infrastructure or planning body) it is absolutely essential to the long term viability of the transit investment (SKMG 1996, p. 4). The transit accessible area around the stations is generally far larger than the Transit Companys real estate can reach. Many studies have been undertaken to define the influence zone of transit stations, i.e. the probability that at a certain distance from the station an employee or resident is ready to use transit as a transportation alternative for commuting or other travel purposes. Walking distance is the general qualification, that means five to fifteen minutes walking time, depending on the travel purpose, the travel alternatives and the system performance. It is obvious that the attraction is more important at stations of highly performing transit systems. Frequent Rapid Transit service has potentially more impact then Light Rail Service, especially when the Light Rail line is short and/or when the station is less frequented. Document type: Book
Abstract
Although urban development around transit stations doesnt lead to a direct financial contribution for the Transit Agency (or other infrastructure or planning body) it is [...]
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Model Predictive Current Control of a Slow Battery Charger for Electric Mobility Applications
J. Afonso, J. Afonso, J. Afonso, D. Pedrosa, V. Monteiro, R. Gomes, D. Pedrosa, V. Monteiro, R. Gomes

Collection of open chapters of books in transport research (2016). Vol. 2016, 14

Abstract
This paper presents a model predictive current control applied to a slow electric vehicle (EV) battery charger. Taking into account the similarities between the power converters inside the EV, it is possible to combine the battery charger and the motor driver in a single integrated converter, thus reducing the weight and volume of the proposed solution, and also contributing to reduce the final price of the EV. Due to the bidirectional power flow capability of the integrated power converter, when working as a slow EV battery charger it can operate in grid-to-vehicle (G2V) mode and in vehicle-to-grid (V2G) mode, contributing to make EVs an important assets in the future smart grids. The integrated power converter working as battery charger operates with sinusoidal current and unitary power factor, contributing to improve the power quality of the electrical grid. This paper provides simulation and experimental results that validate the model predictive control algorithm applied to the proposed integrated power converter working as slow EV battery charger. (undefined) info:eu-repo/semantics/publishedVersion Document type: Part of book or chapter of book
Abstract
This paper presents a model predictive current control applied to a slow electric vehicle (EV) battery charger. Taking into account the similarities between the power converters [...]
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Model predictive control of an on-board fast battery charger for electric mobility applications
J. Monteiro, D. Pedrosa, J. Fernandes, R. Gomes, R. Gomes, V. Monteiro, V. Monteiro, J. Monteiro, J. Afonso, D. Pedrosa

Collection of open chapters of books in transport research (2016). Vol. 2016, 13

Abstract
Under the necessities of reducing emissions and air pollution, and also for increasing fuel economy, automotive companies have been developing electric and plug-in hybrid electric vehicles. Since these vehicles are parked when the batteries are being charged, it is possible to use the traction power converter as on-board charger, also allowing to reduce weight, volume and costs of components in the vehicle. In this context, this paper presents a model predictive control algorithm for an on-board fast battery charging that uses the traction power converter of an electric vehicle. Simulation results and system implementation are depicted, and finally, are presented some experimental results obtained with the proposed control system. (undefined) info:eu-repo/semantics/publishedVersion Document type: Part of book or chapter of book
Abstract
Under the necessities of reducing emissions and air pollution, and also for increasing fuel economy, automotive companies have been developing electric and plug-in hybrid [...]
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Mobility Management for Cellular Networks:From LTE Towards 5G
L. Gimenez

Collection of open chapters of books in transport research (2017). Vol. 2017, 10

Abstract
Document type: Book
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The great recession and job loss spillovers impact of tradable employment shocks on supporting services
H. Nguyen, S. Rezaei

Collection of open chapters of books in transport research (2016). Vol. 2016, 12

Abstract
This paper explores the spillover effects of job losses via input linkages during the Great Recession. Exploiting exogenous variation in tradable employment shocks across U.S. counties, the paper finds that job losses in the tradable sectors cause further job losses in local supporting services. The result is not due to reverse causation, construction job losses, or credit shortages. In addition, the paper finds that logistic supporting services are relatively more affected by local tradable job losses, while professional supporting services, such as information technology and management consulting, are more affected by the job losses in neighboring counties. Document type: Book
Abstract
This paper explores the spillover effects of job losses via input linkages during the Great Recession. Exploiting exogenous variation in tradable employment shocks across [...]
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Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere
B. Stevens, H. Brogniez, C. Kiemle, J. Lacour, C. Crevoisier, J. Kiliani

Collection of open chapters of books in transport research (2017). Vol. 2017, 8

Abstract
In situ, airborne and satellite measurements are used to characterize the structure of water vapor in the lower tropical tropospherebelow the height, (Formula presented.) of the triple-point isotherm, (Formula presented.) The measurements are evaluated in light of understanding of how lower-tropospheric water vapor influences clouds, convection and circulation, through both radiative and thermodynamic effects. Lower-tropospheric water vapor, which concentrates in the first few kilometers above the boundary layer, controls the radiative cooling profile of the boundary layer and lower troposphere. Elevated moist layers originating from a preferred level of convective detrainment induce a profile of radiative cooling that drives circulations which reinforce such features. A theory for this preferred level of cumulus termination is advanced, whereby the difference between (Formula presented.) and the temperature at which primary ice forms gives a first-mover advantage to glaciating cumulus convection, thereby concentrating the regions of the deepest convection and leading to more clouds and moisture near the triple point. A preferred level of convective detrainment near (Formula presented.) implies relative humidity reversals below (Formula presented.) which are difficult to identify using retrievals from satellite-borne microwave and infrared sounders. Isotopologues retrievals provide a hint of such features and their ability to constrain the structure of the vertical humidity profile merits further study. Nonetheless, it will likely remain challenging to resolve dynamically important aspects of the vertical structure of water vapor from space using only passive sensors. © 2017 The Author(s) Document type: Part of book or chapter of book
Abstract
In situ, airborne and satellite measurements are used to characterize the structure of water vapor in the lower tropical tropospherebelow the height, (Formula presented.) [...]
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Agent-based simulation to assess the performance of intersections with pre-signals: comparison with roundabouts
J. Oliveira, L. Dias, G. Pereira, G. Pereira, A. Vieira

Collection of open chapters of books in transport research (2017). Vol. 2017, 7

Abstract
Solving traffic congestion problems in intersections is a complex logistic problem that usually consists in building infrastructures, such as bridges, tunnels, or roundabouts, which represent the costliest solutions. Concerning the case of roundabouts, many parameters influence its performance, e.g. geometry and size. Thus, other less costlier solutions should be pondered. This paper introduces a low-cost approach to traffic intersections, by using pre-signals; and conducts simulation experiments to verify if this approach could be used to improve the performance of traffic intersections. In this sense, an agent-based traffic simulation model was developed that applies the object modelling paradigm of Simio to model the individual behaviour of vehicles. The simulation experiments results indicate that the flow of vehicles can be increased up to 20%, reducing the average queue sizes and crossing time per vehicle and saving the fuel consumed up to 64%. (undefined) info:eu-repo/semantics/publishedVersion Document type: Part of book or chapter of book
Abstract
Solving traffic congestion problems in intersections is a complex logistic problem that usually consists in building infrastructures, such as bridges, tunnels, or roundabouts, [...]
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Comparative analysis of public transport users' perception targeting sustainable transportation
Z. Cakici, Y. Murat

Collection of open chapters of books in transport research (2017). Vol. 2017, 5

Abstract
Public transport is one of the main actors of sustainable transportation. To make an increase in the use of public transport systems and a decrease in private car usage are one of the main purposes of decision makers in many countries. Usage of public transport system has a strong relation with the quality of service. Service quality includes many parameters such as comfort, frequency, information system etc. Fare is another important parameter on demand for public transport systems. All of these parameters are varied by users' perceptions. This study focuses on public transport systems of Denizli, Turkey and investigates users ' perceptions. Bus and paratransit (minibus) modes are regarded in the study. The public survey is performed for these modes. In the surveys, different questions have been asked to participants. Answer of each question is evaluated separately and distribution of each question for gender, ages and jobs are analyzed. Results obtained are summarized and discussed. © 2017, IGI Global. All rights reserved. Document type: Part of book or chapter of book
Abstract
Public transport is one of the main actors of sustainable transportation. To make an increase in the use of public transport systems and a decrease in private car usage are [...]
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Follow the greens the controllers point of view results from a sesar real time simulation with controllers
K. Straube, M. Roßbach, B. Vieten, K. Hahn

Collection of open chapters of books in transport research (2016). Vol. 2016, 9

Abstract
Although pilots are often supported by signage, markings and lighting when taxiing on the airport surface, navigation and monitoring remain workload intense tasks even in good weather conditions. Radio communication is near capacity limits on many airports today resulting in waiting times and delay. Apart from well-known safety issues this also constitutes a negative impact on the environment. The European aviation research program SESAR addressed this problem and came up with a solution: A new surface traffic management concept proposes the automated use of Airfield Ground Lighting with individually switched green taxiway centerline lights indicating the path to be followed. This paper presents official validation results indicating that SESAR developed a safer, quicker and greener surface traffic management concept. Document type: Part of book or chapter of book
Abstract
Although pilots are often supported by signage, markings and lighting when taxiing on the airport surface, navigation and monitoring remain workload intense tasks even in [...]
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Transport Policies and Development
C. Berg, U. Deichmann, Y. Liu, H. Selod

Collection of open chapters of books in transport research (2016). Vol. 2016, 8

Abstract
This survey reviews the current state of the economic literature, assessing the impact of transport policies on growth, inclusion, and sustainability in a developing country context. The findings are summarized and methodologies are critically assessed, especially those dealing with endogeneity issues in empirical studies. The specific implementation challenges of transport policies in developing countries are discussed. Document type: Book
Abstract
This survey reviews the current state of the economic literature, assessing the impact of transport policies on growth, inclusion, and sustainability in a developing country [...]
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Reactive Dynamic Assignment for a Bi-dimensional Traffic Flow Model
K. Sossoe, . Lebacque, J. Lebacque, J. , S. , K.

Collection of open chapters of books in transport research (2016). Vol. 2016, 7

Abstract
International audience This paper develops a graph-theoretic framework for large scale bi-dimensional transport networks and provides new insight into the dynamic traffic assignment. Reactive dynamic assignment are deployed to handle the traffic contingencies, traffic uncertainties and traffic congestion. New shortest paths problem in large networks is defined and routes cost calculation is provided. Since mathematical modelling of traffic flow is a keystone in the theory of traffic flow management, and then in the traffic assignment, it is convenient to elaborate a good model of assignment for large scale networks relying on an appropriate model of flow related to very large networks. That is the zone-based optimization of traffic flow model on networks developed by [8], completed and improved by [9]. Document type: Part of book or chapter of book
Abstract
International audience This paper develops a graph-theoretic framework for large scale bi-dimensional transport networks and provides new insight into the dynamic traffic [...]
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An agent-based simulation framework to evaluate urban logistics schemes
W. van Heeswijk, M. Mes, J. Schutten, A. Paias, M. Ruthmair, S. Voß

Collection of open chapters of books in transport research (2016). Vol. 2016, 6

Abstract
Inefficient urban freight transport has a negative impact on both livability in cities and profit margins in the supply chain. Urban logistics schemes, consisting of governmental policies and company initiatives, attempt to address these problems. However, successful schemes are difficult to realize due to the divergent objectives of the agents involved in urban logistics. Traditional optimization techniques fall short when evaluating schemes, as they do not capture the required change in behavior of autonomous agents. To properly evaluate schemes, we develop an agent-based simulation framework that assesses the interaction between five types of autonomous agents. Compared to existing studies in this field, we contribute by (i) explicitly including company-driven initiatives, and (ii) adopting a supply chain-wide perspective. We illustrate the working of our framework by testing a number of schemes on a virtual network. Document type: Part of book or chapter of book
Abstract
Inefficient urban freight transport has a negative impact on both livability in cities and profit margins in the supply chain. Urban logistics schemes, consisting of governmental [...]
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Portsmouth the island city 1 - mainline rail connectivity: a proposal for change
W. Menteth

Collection of open chapters of books in transport research (2016). Vol. 2016, 5

Abstract
Proposals for a Portsmouth and Solent Region proposed mainline rail strategy. "br/"How Portsmouth and the Solent region with other south of England ring cities can inform future transportation strategy and development, to improve connectivity, sustainability and economic benefit. Document type: Book
Abstract
Proposals for a Portsmouth and Solent Region proposed mainline rail strategy. "br/"How Portsmouth and the Solent region with other south of England ring cities can inform [...]
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Short term traffic congestion forecasting using hybrid metaheuristics and rule based methods a comparative study
E. Osaba, A. Perallos, A. Masegosa, E. Onieva, P. Lopez-Garcia

Collection of open chapters of books in transport research (2016). Vol. 2016, 4

Abstract
In this paper, a comparative study between a hybrid technique that combines a Genetic Algorithm with a Cross Entropy method to optimize Fuzzy Rule-Based Systems, and literature techniques is presented. These techniques are applied to traffic congestion datasets in order to determine their performance in this area. Different types of datasets have been chosen. The used time horizons are 5, 15 and 30 min. Results show that the hybrid technique improves those results obtained by the techniques of the state of the art. In this way, the performed experimentation shows the competitiveness of the proposal in this area of application. Document type: Part of book or chapter of book
Abstract
In this paper, a comparative study between a hybrid technique that combines a Genetic Algorithm with a Cross Entropy method to optimize Fuzzy Rule-Based Systems, and literature [...]
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Communication and Communication Problems Between Autonomous Vehicles and Human Drivers
B. Färber, B. Färber

Collection of open chapters of books in transport research (2016). Vol. 2016, 3

Abstract
Discussions of autonomous land vehicles often invoke the example of air traffic, where the autopilot is responsible for steering except for take-off and landing. The question arises: what can we learn from air traffic? What autonomously flying aircraft and autonomously driving vehicles have in common is that the pilot or driver bears the final responsibility. But, there are a number of differences between road traffic and air traffic (besides their type of locomotion) that make transferring the systems from one to the other impractical. Document type: Part of book or chapter of book
Abstract
Discussions of autonomous land vehicles often invoke the example of air traffic, where the autopilot is responsible for steering except for take-off and landing. The question [...]
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Deep decarbonisation towards 1.5°C-2°C stabilisation
G. Luderer, E. Kriegler, L. Delsa, O. Edelenbosch, J. Emmerling, V. Krey, D. McCollum, S. Pachauri, K. Riahi, B. Saveyn, M. Tavoni, Z. Vrontisi, D. P., . Vuuren, D. Arent, A. Arvesen, S. Fujimori, G. Iyer, I. Keppo, K. Kermeli, S. Mima, E. Ó BROIN, R. Pietzcker, F. Sano, Y. Scholz, B. Van Ruijven, C. Wilson

Collection of open chapters of books in transport research (2016). Vol. 2016, 2

Abstract
Limiting global mean warming to well below 2°C or even 1.5°C relative to pre-industrial levels requires a major transformation of the energy system. The ADVANCE project has analysed this mitigation challenge in detail, from the implications of the Intended Nationally Determined Contributions INDCs) to decarbonisation bottlenecks in energy end-use sectors, taking into account both technological as well as behavioural emission reduction measures. Our key fndings are: The implementation of the Paris Agreement initiates a low-carbon transition for major emitting countries but an intensifcation of global effort is still required in order to limit global warming well below 2°C. In 2030, the implementation of the INDCs is expected to reduce GHG emissions by 10% of pre-Paris Reference emission levels. However, the global emissions gap relative to cost-optimal reduction pathways remains at 14 [4-25]1 GtCO2eq for the 2°C target and 25 [13-30] GtCO2eq for the 1.5°C target. The decarbonisation of the power sector accounts for more than half the CO2 reductions achieved by the INDCs in 2030. It also holds the greatest potential for further near-term eductions which would put the world on track for 1.5-2°C stabilisation. In 2030, the INDCs are expected to generate an increase in the share of zero carbon power supply by 5% [1-12%] relative to pre-existing trends, achieving a total share of 48% [40-66%]. Optimal 2°C and 1.5°C scenarios feature 57% [50-90%] and 73% [57-93%] zero carbon power supply respectively. In contrast, the INDCs have little effect on near-term emissions from non-electric end-use, even though progress in abating emissions, particularly from industry and transportation, is important for 1.5-2°C-consistent climate stabilisation. The 1.5°C temperature target requires reductions in emissions from energy supply and demand as well as removal of CO2 from the atmosphere. A warming limit of 1.5°C requires adherence to a stringent carbon budget of around 400 Gt CO2 or lower over the 2011-2100 period. As the supply-side sector already needs to eliminate nearly all of its emissions by 2050 for 2°C stabilisation, most of the additional emission reductions need to occur on the demand side. Effciency improvements, as well as an accelerated electrifcation, will play a key role in achieving the 1.5C° target. However our analysis also shows that energy supply and demand will still combine to generate at least 1000 Gt of residual CO2 emissions over the 2011-2100 period. Accordingly, a 1.5°C-consistent budget will require cumulative carbon dioxide removal of at least 500 Gt CO2 over the course of the century. Renewable energy from wind and solar power has great potential to produce environmentally friendly and economical electricity supply. Reaping the benefts of high and low-cost emission reduction of the power sector at an early stage is essential for climate change mitigation. We fnd that the sector could be almost fully decarbonised through wind and solar power alone, without the use of nuclear and carbon capture and storage (CCS). This would require, however, considerable additional investments into grid infrastructure and storage systems. Most previous modelling studies have underestimated the role of wind and solar because of overly conservative assumptions on technology costs and the challenges related to coping with a variable renewable electricity supply. We also fnd that the low-carbon transformation yields substantial environmental co-benefts, which outweigh adverse environmental side-effects. Among the alternative decarbonisation pathways available, strategies relying heavily on wind and solar are superior to those with substantial CCS and nuclear deployment, in terms of minimising environmental impacts. Technological developments promoting effciency, electrifcation and use of low-carbon fuels are the key to demand-side emission reductions. Technology options that promote energy effciency, electrifcation and a switch to low-carbon fuels in primary energy demand sectors (transport, industry and buildings), become increasingly important if a climate target of below 2°C is to be achieved. This is despite the continuously increasing demand for energy services. In the long-term, conventional fuels will have to be almost completely phased out from transportation energy use. This will largely depend on the development and adoption of new technologies, but also on life-style changes towards low-carbon transport modes. Policies influencing consumers’ attitudes will need to support the energy transformation. Policies targeting consumers’ behaviour and preferences can encourage the adoption of advanced technologies and use of cleaner fuels. These will ultimately speed-up the transition to a low-carbon energy system. For instance, in the transport sector we find that consumers have different attitudes towards vehicle choice, apart from pure fnancial concerns. This is why a rise in the market in alternative fuel vehicles will critically depend on non-fnancial measures, such as vehicle effciency standards and mandates, refuelling infrastructure investments and exclusive access to parking spaces and roadways. Also, with regard to energy access in developing countries, we fnd that household cooking decisions largely depend on income. Therefore subsidies for cleaner fuels and stoves can speed up the transition to universal clean cooking and even offset the negative effects of rising fuel costs spurred by climate policy. Document type: Book
Abstract
Limiting global mean warming to well below 2°C or even 1.5°C relative to pre-industrial levels requires a major transformation of the energy system. The ADVANCE project [...]
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Experimental Design of a Polymeric Solution to Improve the Mobility Ratio in a Reservoir previous implementation of a pilot project of EOR
V. Cuenca, R. Paredes, J. Cóndor

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 78

Abstract
This paper describes experimental formulations of polymeric solutions through lab evaluations with the objective of finding optimum solution concentration to fluid mobility in reservoirs as previous step before implementing a pilot project of enhanced oil recovery. The polymers, firstly, were selected based on the properties from fluids from reservoir. Two types of polymers were used TCC-330 and EOR909 and the experimental tests were: thermal stability, compatibility, adsorption, salinity, and displacement. The design with the best results was with polymer TCC-330 at 1,500 ppm concentration.
Abstract
This paper describes experimental formulations of polymeric solutions through lab evaluations with the objective of finding optimum solution concentration to fluid mobility [...]
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Natural coagulation for the decontamination of industrial effluents
C. Banchón, R. Baquerizo, D. Muñoz, L. Zambrano

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 77

Abstract
Industrial and agricultural pollution has generated undoubtedly a high environmental impact on the natural resources of our planet. Deficiencies in the provision of water for human consumption due to pollution from natural sources are expected. In response to this, the application of iron and aluminum coagulants are the first choice for wastewater treatment. However, the abundant use of aluminum is subject of discussion because of the potential impact on humans. Therefore, this article highlights the latest advances in the field of natural coagulation, an ancestral technology used for water decontamination. Its proven effectiveness is based on electrokinetic destabilization mechanisms that remove turbidity up to 99%. Experimental evidence agrees that concentrations of tannins and mucilages allow the remediation of effluents from chemical industries such as textile and tanneries.
Abstract
Industrial and agricultural pollution has generated undoubtedly a high environmental impact on the natural resources of our planet. Deficiencies in the provision of water [...]
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Design and implementation of a YAGI Microstrip antenna to 5.8 GHz
A. Gordón, R. Llugsi

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 76

Abstract
In this paper the design of a Yagi microstrip antenna will be done. Two well know design techniques will be analyzed: tables and mathematical equations. The design of microstrip antennas is compact, lightweight and relatively cheap. The material selection is overriding and the RO4003c substrate has been chosen due to its satisfactory operation at 5.8 GHz. Later tests are carried out in an anechoic chamber assembled to operate from DC to 10 GHz. Finally antenna parameters such as directivity, impedance, VSWR, return losses and radiation pattern are determined.
Abstract
In this paper the design of a Yagi microstrip antenna will be done. Two well know design techniques will be analyzed: tables and mathematical equations. The design of microstrip [...]
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Influence of climatic variables on wireless: case study Base-Station Receiver
R. Najarro Quintero, E. Samaniego Mena, F. Fares Vargas, A. Puris Cáceres

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 75

Abstract
The development of this research is done with the aim of finding the relationship betweenweather conditions and the loss of wireless connection. The data were obtained by ameteorological center of the area and a telecommunications company that operates in the sameplace. We studied different models based on fuzzy logic due to the easy interpretation the easyinterpretation of the rules and data management. We used the Weka application that providestools for pre-processing of data and Keel software tool for data classification. Nine classifiersbased on fuzzy rules were applied, where the Furia-C was that better results obtained in orderto quality and quantity of rules. In this scenario, a preprocessing of data were computed, wheresome techniques to improve the information was performed. Some of the obtained rulerscorroborate the influence of heavy rain over the loss of the signal, but other relationships thatincorporate new knowledge in the area, such as dew point and the average relative humidityappear.
Abstract
The development of this research is done with the aim of finding the relationship betweenweather conditions and the loss of wireless connection. The data were obtained by [...]
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Use of membrane technology and resins for the separation and purification of polyphenols purple tree tomato (Solanum betaceum Cav)
E. Beltrán, D. Pallet, E. Vera, J. Ruales

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 74

Abstract
The polyphenols fractionation of mesocarp juices, placenta and purple tree tomato peel using the pore size of the membrane as a means of selection was performed using micro and ultrafiltration tangential; tests made with HPLC showed that fractionation of phenolic compounds was not performed. The processes of concentration of the clarified juices of placenta and tree tomato peel by reverse osmosis obtained a volumetric concentration factor of 2 and 2.2 respectively. The polyphenol concentration increased by 1.5 times for placenta and 2.4 times for peel and antioxidant capacity increased by 2.4 times for both juices. The anthocyanins of placenta increased by 2.6 times. The use of the resin XA 5071 FG concentrated phenolic compounds with an increase of antioxidant capacity in a range between 4 and 5.5, and anthocyanins concentration was increased 1.8 times in the placenta juice. In conclusion the process of polyphenols concentration of tree tomato was more efficient using the resin XA 5071 FG than the reverse osmosis applied in this research.
Abstract
The polyphenols fractionation of mesocarp juices, placenta and purple tree tomato peel using the pore size of the membrane as a means of selection was performed using micro [...]
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Strategies for conservation of highland ecosystem in Pulinguí San Pablo and Chorrera Mirador, Ecuador
P. Lozano, A. Armas, V. Machado

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 73

Abstract
To drive conservation processes and sustainable use of an ecosystem implies, on the one hand, the understanding of the territory as a socio-ecosystem, and on the other hand, the application of the ecosystemic approach. For this reason, this is a tool that contributes to the highland ecosystem management of the communities Pulinguí San Pablo and Chorrera Mirador. This process was based on the socio-ecosystem characterization, determination of conservation elements and formulation of conservation and use of sustainable strategies. Data show that 186 habitants live in these socio-ecosystem and mainly benefit from three types of ecosystemic services: supply, regulation and cultural, carrying out agricultural, livestock and touristic activities. These settlements exert a moderated anthropic pressure in the socio-ecosystem due to the fact that only 98,65 hectares (out of 4567,20 hectares) are used for these activities. This is reflected in the state of the identified conservation elements that, evaluated according to their size, condition and landscaping context, obtained a mean of 3,3/4,0 (points) which means that they are in a decay process, nonetheless, their impacts may be diminished using established and executed strategies by local populations.
Abstract
To drive conservation processes and sustainable use of an ecosystem implies, on the one hand, the understanding of the territory as a socio-ecosystem, and on the other hand, [...]
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Effect of using hydrogen in the power and performance of an internal combustion engine
E. Tamayo, C. Rosales, A. Guzmán, P. Pazmiño

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 72

Abstract
This study analyzed the real working parameters of an Otto cycle internal combustion engine, using as fuel hydrogen plus gasoline. Two stoichiometric equations were determined. In the first equation, the reagents are octane and air, in the second equation was added the quantity of 3.86 H2 moles obtained from a hydrogen cell. Two sets of equations, for consumption and power, were determined from the chemical equations, working at the conditions of Quito: altitude 2850 msnm, 72.794 kPa of atmospheric pressure and 300 K of temperature. A single cylinder engine powered with hydrogen plus gasoline was used for getting real data of engine power, using mixtures of air-gasoline and hydrogen; the theoretical power without H2 was 3.91 HP and with H2 5.41 HP, it increased 27.1%, the real power is 3.78 HP without H2 and 4.66 HP with H2, it increased 16.7%. Theoretical fuel consumption is 401.61 g/kWh and addition of H2 is less to 373.52 g/kWh, the actual consumption that indicates the manufacturer is 395 g/kWh.
Abstract
This study analyzed the real working parameters of an Otto cycle internal combustion engine, using as fuel hydrogen plus gasoline. Two stoichiometric equations were determined. [...]
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Evaluation of a pilot aerobic reactor with polyetilenterephtalate (PET) as support material for dairy wastewater treatment
M. Muñoz, J. Reina, M. Aldás

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 71

Abstract
A pilot aerobic horizontal plug flow reactor filled with pieces of PET (polyethylene terephthalate), from plastic bottles was installed for treatment of a synthetic substrate prepared from lactic whey with COD values of 800 to 2100 mg/L. A bacterial inoculum previously acclimated to the substrate was used. Organic material removal efficiencies of 62.2%, 85% y 94% were obtained with retention times of 5.14, 6.01 and 8.01 hours, and with volumetric organic loads (Lv) of 7.68, 6.19 and 4.61 kg/day.m3, respectively. Also, the kinetic mass transfer constant (k) was calculated and it presented a value of 0.02 m/day. On the other hand, an F/M ratio of 0.4 was determined, indicating that the process had a similar performance to an extended aeration system. Finally, the biomass generated inside the reactor was analyzed, obtaining a value of 11560 mg /L, which is a higher value than those of conventional systems.
Abstract
A pilot aerobic horizontal plug flow reactor filled with pieces of PET (polyethylene terephthalate), from plastic bottles was installed for treatment of a synthetic substrate [...]
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GPON networks certification, standard ITU G.984.x
E. Quisnancela, N. Espinosa

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 70

Abstract
This article describes the methodology to certify a FTTH GPON network, in order to minimize the errors that tend to show up during the execution of this process within an optical network. The work is based on national and international technical standards, ensuring optimal performance of the network. Empirical methods are used in the field through processes characterization, measurement and analysis of results, which will identify the factors allowing that measurements are within the range set with the use of tools and equipment properly configured and updated. The need for an effective regulation is established in the certification of a FTTH GPON network to bring maximum benefits for companies providing service in the country and meeting the demand for bandwidth of the end customer, ensuring the application of new technologies helping to optimize the use of convergence oriented service, the implementation of Next Generation Networks and towards infrastructure investment in strategic sectors.
Abstract
This article describes the methodology to certify a FTTH GPON network, in order to minimize the errors that tend to show up during the execution of this process within an [...]
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Interaction Based on Drawing Gestures to Complement the Teaching-Learning Process
A. Vicuña, O. Erazo

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (4), 69

Abstract
Interaction based on hand gestures has experienced a great progress in recent years. Its utility has been verified in several areas, particularly in the educational field, where it can contribute to enhance the quality of education. However, there are still some topics that have received little attention, such as the use of drawing gestures executed in the air with the hand. For this reason, this article analyzes the feasibility of using this type of gestures with educational purposes. With this aim, we conducted a study in which the participants interacted with the developed application by means of several drawing gestures. The obtained quantitative and qualitative results confirm the validity of our proposal. Specifically, the participants’ performance was acceptable according to the values of the used metrics. Moreover, the participants indicated the proposal is interesting and enjoyable. As a consequence, the use of applications of this type, in the classroom or at home, could contribute to increase the students’ interest in the corresponding subject, which should lead to obtain better marks.
Abstract
Interaction based on hand gestures has experienced a great progress in recent years. Its utility has been verified in several areas, particularly in the educational field, [...]
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Comparative study of emission of pollutant gases in vehicle M1, using fuel of the Andean Community
J. Antamba Guasgua, G. Reyes Campaña, M. Granja Paredes

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (3), 68

Abstract
The environmental pollution is a problematics that concerns all countries about the world as result of this pollution there take place the phenomena of climate change, greenhouse effect, acid rain, and diseases in people. To delimit the issues, there were selected the countries that integrate the Andean Community, the project goal is compare by means of static and dynamic tests the values of emission of pollutant gases, with the fuel that is distributed in each of the selected countries. The process of measuring and testing of static tests were developed under NTE INEN 2203:1999 standard, considering the idle condition (820 rpm) and high engine speed (2500 RPM), in both these cases, an constant engine oil temperature of 94 ° C and dynamic tests carried out according to ASM 25/25 and ASM 50/15 cycles, the results that have been achieved with the different fuels in a vehicle Chevrolet Sail, the best-selling in the country. Based on tests developed, the evaluated vehicle will be able to circulate without any disadvantage with any of the fuels of the Andean Community according NTE INEN 2204:2002 standard. Accordingly, the fuel with the lowest levels of emissions of gaseous pollutants is the distributed one in Peru.
Abstract
The environmental pollution is a problematics that concerns all countries about the world as result of this pollution there take place the phenomena of climate change, greenhouse [...]
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Data model management, with the use of artificial intelligence, for a geographic information system in the energetic sector
N. Sánchez Fleitas, R. Comas Rdoríguez, M. García Lorenzo, A. Riverol Quesada

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (3), 67

Abstract
A Geographic Information System (GIS), named SIGOBE v 3.0, for the electric sector is development. The Integral Management System of the ECIE (SIGECIE) and the Integrated Network Management System (SIGERE) databases are taxed alfanumeric information. Studies determined the need for a model for data management, contributing to the GIS development, on a conceptual schema domain capable of responding to different user requests, through automatic query as support decision making. To provide the GIS with a conceptual basis an ontology is determined, which will be expressed by logical descriptive, to generate the traits of a case-based reasoning that allows automation of consultations. The final quality of GIS was verified according to the quality standards of the ISO-9126:2002 standard. The proposed model and its functionality contributes to: facilitate decision-making at different levels, perform risk analysis to have the defects of electrical installations, reduce the time of failure to the key areas of the country, organize the travel of trucks more efficiently and locate electrical faults more accurately.
Abstract
A Geographic Information System (GIS), named SIGOBE v 3.0, for the electric sector is development. The Integral Management System of the ECIE (SIGECIE) and the Integrated [...]
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Quality baseline of the castilla blackberry (Rubus glaucus) in its food chain
F. Iza, X. Rojas-Lema, Y. Argüello

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (3), 66

Abstract
A proposal for improvement in the performance of the food chain of castilla blackberry (Rubus glaucus) in order to potentiate their productivity can only start from a baseline or situational diagnosis of the quality of the fruit and hence identify the main points of improvement. The food chain of the fruit identifies three stages, harvest, post-harvest (storage and transport) and marketing or sale. The diagnosis in each stage began with reverse mode. It was identified the most representative producer and the supplying for traders to the point of sale. The quality evaluation of the fruit was performed through chemical and physical characterization in the four stages. Weight loss or losses were evident in all stages, light no significant changes of color from bright red bluish hue in the collection stage until opaque bluish red or off, at the stage of sale due to the short cycle time and the characteristics non-climacteric fruit. However, at all stages of collection, storage, transportation and sale, they presented significant changes in the indices of maturity which meant an increase of sugars, decreased of pH, and increase acidity. The results indicate that the fruit changed its physicochemical characteristics during the stages of the food chain affecting its productivity.
Abstract
A proposal for improvement in the performance of the food chain of castilla blackberry (Rubus glaucus) in order to potentiate their productivity can only start from a baseline [...]
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The Simplex-Centroid Design and Desirability Function in optimizing the sensory acceptability of sweet bread enriched with Chenopodium quinoa
R. Siche, V. Aredo, L. Velásquez, I. Castillo

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (3), 65

Abstract
The aim of this study was to optimize the sensory acceptability (SA) of an andean sweet bread made with different percentages of wheat flour (WF), quinoa flour (QF) and sugar (S) was optimized through Simplex-Centroid Design (SCD) and Desirability Function (DF). Ten treatments were performed, in which the mixture of different percentages of WF (28% - 52.5%), QF (0% - 24.5%) and S (17.5% - 42%) accounted for 70% of the dough formula. The evaluation of the SA was conducted in triplicate with 20 consumer panelists of sweet bread, applying an unstructured scale from 0 to 10. Statistical analysis of SCD reported that a cubic model successfully explained the effect of WF, QF and S on SA (p = 0.0529 ≈ 0.05 and R2 = 94.49%), analyzing the response surface was observed that the ranges of the percentage that optimize the SA were: 35.35% - 41.97% of WF, 7.11% - 11.03% QF and 20.44% - 24.61% of S. By DF was determined that the percentages that optimize the SA were: 40.25% of WF, 9.05% QF and 20.70% of S.
Abstract
The aim of this study was to optimize the sensory acceptability (SA) of an andean sweet bread made with different percentages of wheat flour (WF), quinoa flour (QF) and sugar [...]
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Quality analysis of effluents from biodigesters in lodges located in the Cuyabeno Wildlife Reserve
I. Gutiérrez Cruz, E. Rivera Carrión, G. Roldán Reascos

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (3), 64

Abstract
In the Cuyabeno Wildlife Reserve near Laguna Grande and Cuyabeno river, several ecological hotels have been built to meet the touristic demand; therefore these eco-lodges generate wastewaters. The Ministry of Environment, responsible for biodiversity conservation, has ordered the implementation of biodigesters for the treatment of these waters. After three years of implementing the system, it is proposed to check the quality of these waters, through the analysis of physical-chemical parameters: temperature, conductivity, pH, sulfates, nitrates and nitrites, detergents, COD, BOD5, oils and fats; and microbiological such as faecal coliforms. These results were compared with the current environmental legislation: TULSMA "Limits discharged to a body of fresh water." Sampling was subject to the provisions of standard Regulation INEN 2 169: 2013 and sampled at the time of high and low rainfall. The results determined that biodigesters only meet the standard regulations in three parameters: nitrates and nitrites; sulfates and temperature; and violate the following regulations: BOD5, COD and pH; while in the remaining four parameters, there is a variation among the results. In conclusion all digesters violate the regulations, at least on one of the parameters.
Abstract
In the Cuyabeno Wildlife Reserve near Laguna Grande and Cuyabeno river, several ecological hotels have been built to meet the touristic demand; therefore these eco-lodges [...]
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Determination of the efficiency of sawdust and coco fiber used as Biofilter for pollutant removal for the treatment of wastewater
J. Vicente Reyes

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (3), 63

Abstract
Water is a resource used by mankind for industrial and domestic needs, which once used, is discharged into the public sewer system or septic tanks. This project proposes an ecological alternative for the treatment of wastewater from domestic use named Biofilter, which is built of living material (worms) and inert material (chip and gravel), which filters the wastewater; the biological filter has shown high efficiency in the removal of organic matter and pathogens. The field work was carried out with experimental biological filters, to ascertain the best composition of inert material, different variants were used. Two experimental Biofilters, one using sawdust and the other coco fiber were used in the treatment of domestic wastewater; treated samples from each reactor were subjected to laboratory analysis. The analysis and interpretation of results showed that the Biofilter using sawdust removed 53.53 % of pollutants and is outside the required norm for wastewater treatment and the Biofilter using coco fiber removed 82.37 % of contaminants and is within the Environmental Quality Norm and Effluent Discharge: Water Resource.
Abstract
Water is a resource used by mankind for industrial and domestic needs, which once used, is discharged into the public sewer system or septic tanks. This project proposes an [...]
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Soil and dasometric characterization of a Eucalyptus globulus Labill plantation and management proposal in the lower montane thorny steppe zone, Riobamba, Ecuador
M. Guallpa, S. Rosero, M. Samaniego, E. Cevallos

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (3), 62

Abstract
There is limited information on the growth and yield of the Tasmanian blue gum plantation in Tunshi-ESPOCH homestead in varying physiographic conditions, soil properties and management; for this reason it was decided to assess its forest mass. Circular plots were installed with 12.62 m radius at an intensity of 5-6% ha-1. Through systematic unaligned sampling for lifting dasometric information and digging three pits stand-1, using stratified sampling for variables of the place. The application of statistical estimators, determined at an altitude of 2755 amsl, a total average tree volume estimated-1 of 2.32 m3 compared with 0.25 m3 at an altitude of 2929 amsl. Two areas of conservation and other forest use were defined. There are significant associations between total unit volume of T. blue against altitude, organic matter content, cationic exchange capacity at surface level and level of boron underlying level, generating a management strategy for each defined area.
Abstract
There is limited information on the growth and yield of the Tasmanian blue gum plantation in Tunshi-ESPOCH homestead in varying physiographic conditions, soil properties and [...]
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Litterfall production under pine plantations in the southern Andes region of Ecuador
P. Quichimbo, D. Veintimilla, Y. Carrión, L. Jiménez

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (3), 61

Abstract
Litterfall research is an interesting aspect in environmental studies due to its significance in nutrient cycling specially in regions like the Andes where the interactions between biomass production and its decomposition is poorly understood. This study is focusing in the litterfall biomass production under pine plantations in southern Ecuador. The litterfall production was studied for five months at two-week intervals in three pine forest sites located in the southern Andes region of Ecuador. Monthly litterfall production ranged between 1067-1907 kg ha-1, in comparison with other coniferous stands around the world, this study revealed a higher litterfall production for tropical areas and particularly the highest production under pine plantations in the Andes region. This high litterfall production highlights the upmost importance of this forest component as a potential nutrient reservoir involved in the global nutrient cycling under landscapes dominated by this exotic forest specie in the tropical Andes.
Abstract
Litterfall research is an interesting aspect in environmental studies due to its significance in nutrient cycling specially in regions like the Andes where the interactions [...]
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Corn (Zea mays) growth in petroleum contaminated soil, remediated with orange (Citrus sinensis) peel extract
T. Marín Veláquez

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (3), 60

Abstract
Soil pollution has a strong impact when oil activity takes place within a savanna ecosystem. Any oil spill affects agricultural soils. Biostimulation with orange peel extract (Citrus sinensis) is an alternative for remediation of soil contaminated with crude oil and in this research the corn plant (Zea mays) was used as a biomarker of contamination level of a savanna soil after their treatment. Three samples of savannah soil contaminated with oil light crude were treated with dissolutions 1, 3 and 5% of extract of orange peel in water at a dose of 150 mL per kg of soil treated. The content of oils and fats was measured every 7 days, up to 42 days. Corn seeds were planted in soil samples, their growth was measured every 5 days for a period of 35 consecutive days, comparing their growth with seeds planted in a soil sample without contamination. According to an analysis of rank contrast, the plant growth was statistically the same in all samples up to 20 days; from there, evident differences regarding the pattern were shown.
Abstract
Soil pollution has a strong impact when oil activity takes place within a savanna ecosystem. Any oil spill affects agricultural soils. Biostimulation with orange peel extract [...]
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Details of large-panel buildings seismic analysis
S. Emelyanov, Y. Nemchinov, V. Kolchunov, I. Yakovenko

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 59

Abstract
The normative requirements of different European countries, USA, CIS, Canada, etc. codes on ensuring of buildings and structures safety at earthquakes are analyzed. The methodology based on non-elastic response spectrum of buildings and allows taking into account non-linear behaviour of structure are proposed in elaboration of Eurocode 8 requirements. The report provides the calculation examples of non-linear displacements of framed and frameless concrete buildings with application of that methodology.
Abstract
The normative requirements of different European countries, USA, CIS, Canada, etc. codes on ensuring of buildings and structures safety at earthquakes are analyzed. The methodology [...]
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Referential calculation of particulate matter in the air as a factor of environmental pollution in the urban area of the city of Pujilí
P. Vallejo Choez, C. González Moya, F. Mena Mora

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 58

Abstract
This is a preliminary investigation on the environmental quality of the city of Pujilí, made from the collection of samples of particulate matter and vehicular traffic counts on six points of the city. The methodology is based on the provisions of the Unified Text of Secondary Environmental Legislation for measuring atmospheric particulate matter, and the use of count tables for vehicle registration. The results reflect the impact of vehicular traffic, the characteristics of the rolling road layer, soil erosion, and climate on air pollution and its impact on the health of the population.
Abstract
This is a preliminary investigation on the environmental quality of the city of Pujilí, made from the collection of samples of particulate matter and vehicular traffic counts [...]
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Anaerobic horizontal flow reactor with polyethylene terephthalate as support material
M. Muñoz, V. Fuentes, M. Aldás

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 57

Abstract
A pilot anaerobic reactor was installed to remove the organic load of wastewater from dairy industry. It uses a bacterial inoculum previously acclimated to the substrate. It was disposed horizontally and filled with pieces of polyethylene terephthalate (PET), from plastic bottles. The reactor was operated at room temperature, during 100 days, in three phases: 1) the reactor was stabilized with volumetric organic load from 0.013 to 0.500 kg/day.m³; 2) the hydraulic retention time was of 1 day and the volumetric organic load of 3 kg/day.m³; 3) the volumetric organic load was incremented from 4 to 6.6 kg/day.m³ and the hydraulic retention time was 1 day. Organic material removal efficiencies was of 85%, and approximately 75% were obtained in the second and third phase, respectively. The Y value was 0.15, indicating that 0.15 kg of biomass were generated by kg of QDO supplied to the reactor. Finally, the biomass generated inside the reactor was analyzed, obtaining a value of 18868 mg/L, which is a higher value than those of conventional systems.
Abstract
A pilot anaerobic reactor was installed to remove the organic load of wastewater from dairy industry. It uses a bacterial inoculum previously acclimated to the substrate. [...]
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Diversity of vascular flora at Andino's Choco area in Selva Virgen
X. Aguirre Ulloa, A. Endara

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 56

Abstract
The forest near the Hostería Selva Virgen, located in Pichincha, northwestern Andean Chocó area, is one of the biodiversity hotspots in the world, reason that determined the analysis of the vascular flora in the zone. For this study we did a temporary transects of 50 x 4 and 50 x 2 m covering an area of 0.1 hectares. We calculated Sorensen, Simpson and Shannon indexes, using the Past software, obtaining the following results: 159 species (spp.) registered corresponding to 121 genera and 54 families. Families with more species were: 15 spp Moraceae, Rubiaceae 10 spp, Arecaceae 9 spp, Fabaceae 9 spp, Melastomataceae 8 spp and Meliaceae 8 spp. The diversity obtained has a value of 0.95. It is interpreted in the Simpson index as a high diversity. Richness was 0.33, interpreted as an average richness. Sorensen index identifies areas that share more species. Endemism is low: 6.25%. The high biodiversity found in the studied forest shows an important biological richness; therefore more studies are suggested, because this zone has been rarely explored from the biological point of view.
Abstract
The forest near the Hostería Selva Virgen, located in Pichincha, northwestern Andean Chocó area, is one of the biodiversity hotspots in the world, reason that determined [...]
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Device for measuring thermal conductivity of composites based on biomass waste
L. Velasco Roldan, L. Goyos Pérez, R. Delgado García, L. Freire Amores

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 55

Abstract
A standardized test bench has been designed, built and calibrated to determine the thermal conductivity of insulating building materials. The device, simple in design and economical, aims to become a replicable and useful tool for the development of multiple research on innovative materials based on waste or unvalued resources for the production of non-industrial and locally produced cheap thermal insulating materials which lead to the improvement of buildings energy efficiency. The main contribution of the test bench is the possibility of analyzing insulation compounds with more thickness and different formats thanks to the press design, which allows the setting and the pressure of the plates on the samples, holding these in the air and preventing any transmission by unwanted conduction.
Abstract
A standardized test bench has been designed, built and calibrated to determine the thermal conductivity of insulating building materials. The device, simple in design and [...]
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Design and implementation of a control system to improve the quality of the combustion gases in the fire-tube boiler of 5 BHP
C. Pérez Albán, A. Cordovés García, J. Terán Benalcázar

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 54

Abstract
The goal of this paper is the design and implementation of a system for controlling the quality of the combustion gases in a fire-tube boiler of 5 BHP. Based on the percentage of O2 present in the combustion gases, measured by a lambda sensor, the percentage of CO2 emitted into the atmosphere is determined. PID proportional control is responsible for the automatic regulation of the entry of air to the boiler by an actuator, according to the percentage of the oxygen concentration in the combustion gases. The control system has an HMI display and a modular PLC. The results achieved ensure pollutant gases emissions within the parameters established by current environmental standards, achieving the required quality of combustion gases and reducing the fuel consumption of the boiler.
Abstract
The goal of this paper is the design and implementation of a system for controlling the quality of the combustion gases in a fire-tube boiler of 5 BHP. Based on the percentage [...]
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Actuator prototype system by voice commands using free software
J. Andrango, E. Gómez

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 53

Abstract
This prototype system is a software application that through the use of techniques of digital signal processing, extracts information from the user's speech, which is then used to manage the on/off actuator on a peripheral computer when vowels are pronounced. The method applies spectral differences. The application uses the parallel port as actuator, with the information recorded in the memory address 378H. This prototype was developed using free software tools for its versatility and dynamism, and to allow other researchers to base on it for further studies.
Abstract
This prototype system is a software application that through the use of techniques of digital signal processing, extracts information from the user's speech, which is then [...]
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Security of IP Telephony in Ecuador: Online Analysis
J. Estrada, M. Calva, A. Rodriguez, C. Tipantuña

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 52

Abstract
Telephony is a global service and thus telephone networks have been a coveted target for criminals. Now that voice can be transported over IP and that multiple services are integrated in a convergent model through Internet, there are more incentives to attack and more attackers. Moreover, the development of open source telephone applications has encouraged the massive use of IP telephony, but not an increased awareness about embedded security risks. Due to the current and intensive adoption of IP telephony systems in Ecuador, we conducted an exploration based on public information to obtain statistics about telephone systems connected to Internet in Ecuador. Additionally, using a deliberately vulnerable IP telephony system, we collected more data to do a preliminary analysis of threats to such systems. We found that hundreds of telephone systems were publicly available on the Internet and using outdated versions of Asterisk-based applications. We also found thousands of malicious interactions on the IP telephony system we deployed on the Internet.
Abstract
Telephony is a global service and thus telephone networks have been a coveted target for criminals. Now that voice can be transported over IP and that multiple services are [...]
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An evolutionary computational approach for the dynamic Stackelberg competition problems
L. Arboleda-Castro, O. Cedeño-Fuentes, I. Jacho-Sánchez, P. Novoa-Hernández

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 51

Abstract
Stackelberg competition models are an important family of economical decision problems from game theory, in which the main goal is to find optimal strategies between two competitors taking into account their hierarchy relationship. Although these models have been widely studied in the past, it is important to note that very few works deal with uncertainty scenarios, especially those that vary over time. In this regard, the present research studies this topic and proposes a computational method for solving efficiently dynamic Stackelberg competition models. The computational experiments suggest that the proposed approach is effective for problems of this nature.
Abstract
Stackelberg competition models are an important family of economical decision problems from game theory, in which the main goal is to find optimal strategies between two competitors [...]
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Viability study of a system for filtercake remotion in pay zone of oil wells
W. ZhaoZheng, F. Xi, H. Romero Cortez, F. Ramos Aguirre

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (2), 50

Abstract
This article describes the essential ideas of an experimental procedure performed in order to check the filter-cake removal system is suitable for use like filter-cake removal system for pay zone. This system is made on aqueous phase and its concentration depend of the quantity of filtercake estimated in the wellbore of horizontal wells. This optimized the wellbore cleaning and increase the worth of well. The results of tests show that system could work, but it needs further analysis for determine the compatibility with fluids and rock from reservoir.
Abstract
This article describes the essential ideas of an experimental procedure performed in order to check the filter-cake removal system is suitable for use like filter-cake removal [...]
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Medicinal palms of the New World
A. Argüello Mejía

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (1), 49

Abstract
The present investigation comprehends a bibliographical summary of the medicinal uses of the palms in the New World. This compilation is based on publications stating medicinal uses of palms since mid XIX century. There are described the species of palms and its medicinal uses in various places in America. A list of species and the medicinal uses of each one is also included.
Abstract
The present investigation comprehends a bibliographical summary of the medicinal uses of the palms in the New World. This compilation is based on publications stating medicinal [...]
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Design and Implementation of an Automated Management Platform for P2P Transactions with Electronic Money
A. Alcocer, G. Olmedo

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (1), 48

Abstract
Electronic money is a payment tool implemented by the Ecuador’s Central Bank, it allows people to make commercial transactions using their cellphones; it can be used to pay into big chain stores like supermarkets, known as "macro agents", but it also can be employed for the consumption of goods and services into particular businesses such as restaurants or small shops by using “person to person” transfers known as P2P. However, the particular businesses present some disadvantages compared to the macro agents, the main one is the lack of a system that allows them to have a record of the transactions made with electronic money. This article details the design and implementation of a technological platform that allows all types of businesses and people to keep records of their P2P transactions into an automated system with the ability of generating payment’s balance sheets which can be easily viewed through Internet. A research was conducted in order to look for the most efficient technical solution to optimize the available resources. The use of this platform as an external tool extends the capabilities currently provided by the electronic money system.
Abstract
Electronic money is a payment tool implemented by the Ecuador’s Central Bank, it allows people to make commercial transactions using their cellphones; it can be used to [...]
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Management of productive reserves in a SME of Santo Domingo de los Tsáchilas
R. Martínez Vivar, A. Sánchez Rodríguez, G. García Vidal, R. Pérez Campdesuñer

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (1), 47

Abstract
The development of a methodology for the organization of work in the SME, which enables the identification of existing productive reserves and thus a consequent improvement of the indica-tors of labor productivity is the goal of the present investigation. To achieve this objective a pro-cess adapted to the conditions of the object of practical study, which from a holistic approach al-lowed the realization of analysis for the proposed organization of work. The main results can be highlighted the following: the existence of a waste of working time 15% primarily determined by wasting time in the day, likewise it allowed identifying the limiting capacity of the production pro-cess of the natural medicine Prostageron, as well as problems associated with noise, vibration, lighting and ventilation were identified, although there are no major problems that could harm the health of workers. Finally he was able to increase labor productivity in 35.42% compared with the analysis developed linked to the detected limited capacity, while in this first analysis for field observation can indicate the possibility of a production increase of 327%
Abstract
The development of a methodology for the organization of work in the SME, which enables the identification of existing productive reserves and thus a consequent improvement [...]
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Modeling and numerical simulation of the Richards equation for infiltration problems
I. Naula Reina, G. Albuja Proaño, R. Carrillo Flores, C. Izurieta Cabrera

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (1), 46

Abstract
One of the most important natural resources we have is the soil and it is of great interest to the society to take care of them and not to pollute it. In the study of this issue, we are going to consider one of the most common forms of soil contamination due to an infiltration process. It is therefore that it is essential to address study and clearly understand this process by developing a mathematician model, which will be a representation of this physicist phenomenon. Then design and implement a computer program that simulates the infiltration of liquid pollutants in a given area. In this paper we will develop a mathematical model for two-dimensional infiltration in the saturated zone of porous media, based on the equation in nonlinear partial differential Richards Also, It will present a numerical solution through finite element method and first order This paper shows the computational implementation using a simulator that presents graphically the process of pollution afflicting the ground, exposed to certain pollutants, such as the oil spill in regions of eastern Ecuador, wastewater near industrial complexes, among others, over a certain period of time. Finally, this paper will allow for remedial studies in the case are already contaminated soils or preventive areas established as hazardous.
Abstract
One of the most important natural resources we have is the soil and it is of great interest to the society to take care of them and not to pollute it. In the study of this [...]
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Composition and diversity of High Andean in the Fauna Production Reserve Chimborazo, Ecuador
J. Caranqui, P. Lozano, J. Reyes

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (1), 45

Abstract
The present study inquire the floristic diversity of 9 sampling in four plots of 1 m² of high andean in several locations in the “Reserva de Producción de Fauna Chimborazo”. For the development of this study, we used an adaptation of the method of plots “Gloria”. With coverage (%) in each of the plots, Further the diversity indices and similarity with respective analysis were obtained. The data obtained reflect a diversity that can range from medium to low, believe that this is due to anthropogenic activities that have taken place in these ecosistems. With the presence mostly Calamagrostis intermedia, it could establish that the type of vegetation is herbaceous in high andean is higher percentage; is the species that is almost always present in most types of vegetation of the RPF Chimborazo and high dominance that influences the results of low floristic diversity indices was found in the analysis. As a result the most abundant family Asteraceae is well Poaceae.
Abstract
The present study inquire the floristic diversity of 9 sampling in four plots of 1 m² of high andean in several locations in the “Reserva de Producción de Fauna Chimborazo”. [...]
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Biodegradation of organic contaminants from the dairy industry
D. Prócel, P. Posligua, C. Banchón

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (1), 44

Abstract
One of the environmental aspects of high impact in dairy industries is the discharge of wastewaters, because of contaminating organic matter as well as the substantial generation of effluents. In the present study, a biofiltration of effluents from a dairy industry in San Miguel de Nono (Ecuador) with a pollution load of 10.000 mg/L in terms of chemical oxygen demand and turbidity of 799 NTU was implemented. The system with a capacity of 55 L per batch consisted of three biofilters in series and activated zeolite assisted clarification. Organic degradation reached 98,9%; turbidity removal was 95,2%, 94,4% of nitrogen and 89,1% of phosphorus. The presence of milk fat did not decrease the efficiency of the biofiltration but increased the removal of suspended matter and pH neutralisation in the clarification. The optimal operating time was 6 hours under aerobic conditions.
Abstract
One of the environmental aspects of high impact in dairy industries is the discharge of wastewaters, because of contaminating organic matter as well as the substantial generation [...]
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Dairy industry wastewater electrocoagulation
P. López, A. Harnisth

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (1), 43

Abstract
The dairy industry generates lots of water discharge processes, these wastewater are discharged directly into water sources without any pretreatment. . In order to solve this problem there is a treating technique called electrocoagulation that treat of waste water with high organic load. There are three factors to carry out the electrocoagulation process as: time, number of plates and system voltage. After completing the set up and running the experiment, the electrocoagulation treatment efficiency was evident, as the approximate percentage of COD removal was 93%, 82% of BOD5 and 76% of SS.
Abstract
The dairy industry generates lots of water discharge processes, these wastewater are discharged directly into water sources without any pretreatment. . In order to solve this [...]
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Implementation of lean manufacturing in a food enterprise
J. Viteri Moya, E. Matute Déleg, C. Viteri Sánchez, N. Rivera Vásquez

Enfoque UTE - Scientific Engineering Journal (2016). Vol. 7, (1), 42

Abstract
The current industrial competitiveness requires companies to adopt better production methodologies, in order to reduce costs and maximize profits. This is where the adoption of lean manufacturing culture in organizations can generate changes in mentality that focus on free trade of all types of waste, without neglecting the quality. This research aimed to implement the thinking and principles of this philosophy in a food processing company to use resources efficiently, reduce costs and generate higher profits. More than performing a process map and detailed description of key operational processes, three tools of lean manufacturing were used. With 5s was established a clean and orderly work, with the tool just in time waste of different nature including cycle time production decreased; and with VSM the value chain and the new way of working was plotted, without waste.
Abstract
The current industrial competitiveness requires companies to adopt better production methodologies, in order to reduce costs and maximize profits. This is where the adoption [...]
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Advanced solid elements for sheet metal forming simulation
V. Mataix Ferrándiz, R. Rossi, E. Oñate, F. flores

(2016). Journal of Physics: Conferences Series, Cesar de Sa J. M. A., Neto E. S., Cardoso R. P. R., Adetoro O. B. (eds), Vol. 734 (3), pp. 032128

Abstract
The solid-shells are an attractive kind of element for the simulation of forming processes, due to the fact that any kind of generic 3D constitutive law can be employed without any additional hypothesis. The present work consists in the improvement of a triangular prism solid-shell originally developed by Flores. The solid-shell can be used in the analysis of thin/thick shell, undergoing large deformations. The element is formulated in total Lagrangian formulation, and employs the neighbour (adjacent) elements to perform a local patch to enrich the displacement field. In the original formulation a modified right Cauchy-Green deformation tensor (C) is obtained; in the present work a modified deformation gradient (F) is obtained, which allows to generalise the methodology and allows to employ the Pull-Back and Push-Forwards operations. The element is based in three modifications: (a) a classical assumed strain approach for transverse shear strains (b) an assumed strain approach for the in-plane components using information from neighbour elements and (c) an averaging of the volumetric strain over the element. The objective is to use this type of elements for the simulation of shells avoiding transverse shear locking, improving the membrane behaviour of the in-plane triangle and to handle quasi-incompressible materials or materials with isochoric plastic flow.
Abstract
The solid-shells are an attractive kind of element for the simulation of forming processes, due to the fact that any kind of generic 3D constitutive law can be employed without [...]
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A reduced order modeling approach for optimal allocation of Distributed Generation in power distribution systems
R. García-Blanco, P. Diez, D. Borzacchiello, F. Chinesta

International Energy Conference (ENERGYCON) (2016). (preprint) pp, 1-6

Abstract
This paper presents an “offline-online” strategy for optimal allocation and sizing of Distributed Generation. In traditional optimization approaches, each function evaluation requires the solution of a power flow problem, which makes global optimality a computationally challenging goal. In the proposed strategy the power flow solver is invoked only once and a parametric solution is constructed with a monolithic solver. Despite the fact that the parametrized power flow equations result in a high-dimensional problem, the proposed algorithm is specifically designed to circumvent the curse of dimensionality. This is achieved through the application of Model Reduction, in particular the Proper Generalized Decomposition combined with a nonlinear solver. Numerical examples are carried out for showing the validity of the proposed method.
Abstract
This paper presents an “offline-online” strategy for optimal allocation and sizing of Distributed Generation. In traditional optimization approaches, each function [...]
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Unified formulation of a family of iterative solvers for power system analysis
F. Chinesta, P. Diez, D. Borzacchiello, M. Malik, R. García-Blanco

Electric Power Systems Research (2016). (Preprint) Vol. 140, pp. 201-208

Abstract
This paper illustrates the construction of a new class of iterative solvers for power flow calculations based on the method of Alternating Search Directions. This method is fit to the particular algebraic structure of the power flow problem resulting from the combination of a globally linear set of equations and nonlinear local relations imposed by power conversion devices, such as loads and generators. The choice of the search directions is shown to be crucial for improving the overall robustness of the solver. A noteworthy advantage is that constant search directions yield stationary methods that, in contrast with Newton or Quasi-Newton methods, do not require the evaluation of the Jacobian matrix. Such directions can be elected to enforce the convergence to the high voltage operative solution. The method is explained through an intuitive example illustrating how the proposed generalized formulation is able to include other nonlinear solvers that are classically used for power flow analysis, thus offering a unified view on the topic. Numerical experiments are performed on publicly available benchmarks for large distribution and transmission systems.
Abstract
This paper illustrates the construction of a new class of iterative solvers for power flow calculations based on the method of Alternating Search Directions. This method is [...]
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Numerical modeling of undersea acoustics using a partition of unity method with plane waves enrichment
R. Hospital-Bravo, J. Sarrate, P. Diez

Computational Mechanics (2016). (Preprint) Vol. 57 (5), pp. 717-732

Abstract
A new 2D numerical model to predict the underwater acoustic propagation is obtained by exploring the potential of the Partition of Unity Method (PUM) enriched with plane waves. The aim of the work is to obtain sound pressure level distributions when multiple operational noise sources are present, in order to assess the acoustic impact over the marine fauna. The model takes advantage of the suitability of the PUM for solving the Helmholtz equation, especially for the practical case of large domains and medium frequencies. The seawater acoustic absorption and the acoustic reflectance of the sea surface and sea bottom are explicitly considered, and perfectly matched layers (PML) are placed at the lateral artificial boundaries to avoid spurious reflexions. The model includes semi-analytical integration rules which are adapted to highly oscillatory integrands with the aim of reducing the computational cost of the integration step. In addition, we develop a novel strategy to mitigate the ill-conditioning of the elemental and global system matrices. Specifically, we compute a low-rank approximation of the local space of solutions, which in turn reduces the number of degrees of freedom, the CPU time and the memory footprint. Numerical examples are presented to illustrate the capabilities of the model and to assess its accuracy.
Abstract
A new 2D numerical model to predict the underwater acoustic propagation is obtained by exploring the potential of the Partition of Unity Method (PUM) enriched with plane waves. [...]
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Adaptividade e estimativas de erro orientadas por metas aplicadas a um benchmark test de propagação de onda
L. Steffens, P. Diez, M. Alves

Tendências em Matemática Aplicada e Computacional (2016). (preprint) Vol. 17 (1), pp. 35-53

Abstract
O objetivo deste artigo é estudar a eficiência e a robustez de técnicas adaptativas e estimativas de erro orientadas por metas para um benchmark test. As técnicas utilizadas aqui são baseadas em um simples pós-processo das aproximações de elementos finitos. As estimativas de erro orientadas por metas são obtidas por analisar o problema direto e um problema auxiliar, o qual está relacionado com a quantidade de interesse específico. O procedimento proposto é válido para quantidades lineares e não-lineares. Além disso, são discutidas diferentes representações para o erro e é analisada a influência do erro de dispersão. Os resultados numéricos mostram que as estimativas de erro fornecem boas aproximações ao erro real e que a técnica de refino adaptativo proposta conduz a uma redução mais rápida do erro.
Abstract
O objetivo deste artigo é estudar a eficiência e a robustez de técnicas adaptativas e estimativas de erro orientadas por metas para um benchmark test. [...]
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The sisters of the Charity, first nurses of Barquisimeto
L. Valles

Rev Vzlana Salud Pub (2016). 29

Abstract
n 1578, twenty-five years after the city of Nueva Segovia de Barquisimeto was founded, the first sick care center was created in Lara State and Venezuela, which were attended by slaves, this sick shelter was called "Hospital de Santiago" organized by the Spanish conquerors and promoted by the Cleric Pedro del Castillo, it would later be called "Hospital of San Lazaro" that would prevail between 1812 and 1837. Then the "Hospital de La Caridad" was inaugurated in 1918 (Figures 1, 2 and 3) by its main promoter, Dr. Antonio María Pineda, built on the "solar or patio" where the former San Lázaro Hospital (1,2,3), on Obispo Street, (currently Carrera 15 between streets) 25 and 26 of Barquisimeto, Lara State, Venezuela), operating there until 1954, when it would move to its current headquarters north of Avenida Vargas de Barquisimeto, being for this moment the best hospital structure of Venezuela (Figure 4). The Director of the Hospital La Caridad, brought the sisters of La Caridad (Sisters of St. Joseph of Tarbes), who promoted the charity bazaars, organized by the Daughters of Charity Society, which Dr. Pineda himself trained in Barquisimeto, Cabudare , Quibor, Siquisique, Bobare, Yaritagua and Río Claro (Lara and Yaracuy states), where Las Daughters of La Caridad, not only collected money, but all kinds of objects that were raffled, highlighting especially an activity for the benefit of the Hospital carried out in the old Teatro Juárez (Barquisimeto, Venezuela), on April 19, 1918 (declared charity day) (1,2,3).
Abstract
n 1578, twenty-five years after the city of Nueva Segovia de Barquisimeto was founded, the first sick care center was created in Lara State and Venezuela, which were attended [...]
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Amoebic granulomatous encephalitis in an immunocompetent patient
R. Matos, J. Ruiz, L. Casanova, G. Gonzalez

Rev Vzlana Salud Pub (2016). 28

Abstract
Granulomatous amoebic encephalitis is an infrequent clinical entity, usually present in immunocompromised persons, where the few cases reported in the literature are due to infections by free-living amoebas present throughout the world, standing out as the most common agents, the Acanthamoeba sp. and Balamuthia mandrillaris. It is characterized by an insidious clinical course, that can be prolonged, but equally fatal. The clinic corresponds to that of intracerebral space occupying lesions, with seizures and focal deficits such as hemiparesis and cranial nerve lesions. Alterations of the sensorium, headache and neck stiffness are equally common, however, fever is usually sporadic and low grade. Occasionally there are pictures of pneumonitis, kidney or liver failure and sepsis.
Abstract
Granulomatous amoebic encephalitis is an infrequent clinical entity, usually present in immunocompromised persons, where the few cases reported in the literature are due to [...]
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Notes for the history of health care in sarare, state of lara, venezuela.
N. Mascia

Rev Vzlana Salud Pub (2016). 27

Abstract
This essay has the purpose of contributing to the historical reconstruction of the processes, protagonists and health care institutions of Sarare, in the Simón Planas municipality of the } Lara state between the 18th and 19th centuries; also contributing in this way to the social history, to the citizen identity and to the regional history of the medical sciences.
Abstract
This essay has the purpose of contributing to the historical reconstruction of the processes, protagonists and health care institutions of Sarare, in the Simón Planas municipality [...]
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José María Margas: university reform in Caracas 1827-1829, medicine and public health
C. Lizarzado

Rev Vzlana Salud Pub (2016). 26

Abstract
The object of the present work of documentary and bibliographic research is to reconstruct the academic and administrative process carried out by Jose Maria Vargas at the Central University in Caracas during the period 1827-1829 upon the implementation of the Decree on the reorganization of this University signed by Simón Bolívar on June 24, 1827. In this set of changes, the creation of the Anatomy Chair at the university is examined as part of the curriculum reform for the formation of the doctor. The importance of the Chair is emphasized because it constituted the essential unit that organized the university teaching work to grant the academic degrees of Senior, Bachelor, Master and Doctor in the professions of Medicine, Laws and Theology by then. In this order of ideas, aspects of the University reform including the issue of public health are identified as part of the preparation of the doctor. Written evidence is left of this documentary review about the projection and scope of the lectures conducted by Vargas when showing partial data of his disciples and with them cognitive and social institutionalization of Medicine in Venezuela during the nineteenth century.
Abstract
The object of the present work of documentary and bibliographic research is to reconstruct the academic and administrative process carried out by Jose Maria Vargas at the [...]
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Physical hazardous factors and demographic-labor characteristics in workers of an electrical factory
M. Rodriguez, M. Mujica

Rev Vzlana Salud Pub (2016). 25

Abstract
A cross-sectional study was conducted with the objective of analyzing the factors of physical hazards anddemographic-labor characteristics of the workers of an electric corporation in Barquisimeto, Lara State, 91persons attached to the departments of works and design were the population; it was considered a probabilisticsample of 75 workers through a stratified sampling by proportional affixation. A questionnaire was designed(validated according to the judgment of experts and with a Cronbach alpha coefficient = 0.847)
Abstract
A cross-sectional study was conducted with the objective of analyzing the factors of physical hazards anddemographic-labor characteristics of the workers of an electric corporation [...]
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Clinical characteristics of the injuries by prevalent labor accidents in workers of a plastic company.
M. Duran, M. Mujica

Rev Vzlana Salud Pub (2016). 24

Abstract
A cross-sectional investigation was carried out with the objective of analyzing the clinical characteristics of the injuries caused by work-related accidents prevalent in workers of a Plastics Company. The population consisted of 105 records of medical records of workers who suffered accidents at work; 86 records formed the sample estimated by probabilistic sampling, the selection was made with the table of random numbers.
Abstract
A cross-sectional investigation was carried out with the objective of analyzing the clinical characteristics of the injuries caused by work-related accidents [...]
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Serum levels of il-8, il-10, il-13, ifnγ and tnfα in pediatric patients with acute infection with different dengue virus serotypes
J. Casavilca, W. Lopez, E. Mosquera, A. Guerrero, I. Alvarez

Rev Vzlana Salud Pub (2016). 23

Abstract
Dengue is an acute febrile disease caused by four dengue virus (DENV) serotypes whose prevalence in the Americas has quintupled between 2003 and 2013. The immune response against the infection with dengue virus involves cellular and humoral factors. We performed an observational and cross-sectional study to evaluate the levels of interleukins of the innate immune response (IL-8, TNFα), TH1 response (IFNγ), TH2 (IL-13) and regulatory (IL-10) in serum of patients during the acute phase of infection with the DENV1, DENV3 and DENV4 serotypes.
Abstract
Dengue is an acute febrile disease caused by four dengue virus (DENV) serotypes whose prevalence in the Americas has quintupled between 2003 and 2013. The immune response [...]
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Clinical and epidemiological characterization of abortions in adolescents, Dr Israel Ranuarez Balza Guárico State Hospital, 2013.
A. Gonzalez, A. Rodriguez

Rev Vzlana Salud Pub (2016). 22

Abstract
Abortion in adolescents is a public health problem, because the complications arising from its practice are the main cause of death from 10 to 19 years, taking place under conditions that threaten the life, health and integrity of women. In the present investigation, the objective was to characterize clinically and epidemiologically abortions in adolescents seen in the Dr. Israel Ranuarez Balza" Hospital of the Guárico State during 2013. The methodology was a cross-sectional descriptive investigation.
Abstract
Abortion in adolescents is a public health problem, because the complications arising from its practice are the main cause of death from 10 to 19 years, taking place [...]
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Intestinal parasitosis in different indigenous communities zulia state, venezuela.
A. Mora, K. Martinez, A. Roldan, Z. Rodriguez, R. Tello, R. Perozo

Rev Vzlana Salud Pub (2016). 21

Abstract
Parasitic diseases represent a public health problem worldwide, affecting all social classes, especially those lower socioeconomic strata. To determine the prevalence of intestinal parasites in different indigenous communities in the Zulia state, Venezuela, 232 fecal samples corresponding to individuals of both sexes, aged .
Abstract
Parasitic diseases represent a public health problem worldwide, affecting all social classes, especially those lower socioeconomic strata. To determine the prevalence [...]
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Public Health and its determinants.
R. Gásperi

Rev Vzlana Salud Pub (2016). 20

Abstract
Working conditions, housing and housing including all basic services, schooling, education, free time, citizen security, food and civil liberties, together constitute the conditions for people to enjoy a minimum level of Health. Likewise, equitable access to health care must be the primary objective of any health policy, so studying these elements has been a public health concern as a discipline for many years.
Abstract
Working conditions, housing and housing including all basic services, schooling, education, free time, citizen security, food and civil liberties, together constitute the [...]
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Intestinal microbiota and its relationship to metabolic disorders
A. Corro, N. Matheus, C. Medina

Rev Vzlana Salud Pub (2016). 19

Abstract
The complex of organisms that inhabit the intestine and which includes a large number of bacteria, fungi, yeasts, viruses and phage is known as Intestinal Microbiota (MI). The balance between the MI, the epithelial barrier and the local immune system determines intestinal homeostasis in the healthy subject. MI is important in regulating the rescue and energy expenditure, as well as in fat storage and food intake in the host. Due to the increasing impact of metabolic disorders in society, the need to compile, summarize and analyze the most relevant bibliography on recent advances in the understanding of the intestinal microbiota and its possible relationship with these disorders. Investigations with experimental rodent models suggest that the bacterial composition, functional genes and metabolic activities of IM are altered in subjects with obesity, metabolic syndrome or type 2 diabetes (DT2). In addition, it appears that dietary fat is also an important factor affecting the composition of MI, as well as the barrier function of the intestine and therefore, plasma levels of LPS, producing a metabolic endotoxemia that could contribute to the development low-grade systemic inflammation, insulin resistance and DT2. Finally, recent research in rodents indicates that there is a relationship between MI and the pathogenesis of obesity, metabolic syndrome and even DT2.
Abstract
The complex of organisms that inhabit the intestine and which includes a large number of bacteria, fungi, yeasts, viruses and phage is known as Intestinal Microbiota [...]
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Ecoeducation as a linking tool between ecohealth and one health
M. Jiménez

Rev Vzlana Salud Pub (2016). 18

Abstract
This essay aims to contribute to the knowledge and dissemination of new social sciences methodologies applicable to health sciences, which seeks to illustrate the reader about the various current tools that allow, on the one hand, to achieve the necessary changes in the attitudes to improve the live conditions of specific populations in which social needs have been previously diagnosed even under the point of view the biomedical sciences are in accordance with the environment and respect for it; and on the other hand, to demonstrate the imperative need to work in multidisciplinary teams in the search to reduce the factors affect the quality of life of individuals and thus improve statistics and health expectations
Abstract
This essay aims to contribute to the knowledge and dissemination of new social sciences methodologies applicable to health sciences, which seeks to illustrate the reader about [...]
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It is posible to speak of health from disability
H. Sanoja

Rev Vzlana Salud Pub (2016). 17

Abstract
The following essay is a discussion about the possibility of conceptualizing health from disability; to do a review on current notions of health and disability was performed. The concept of health has gone through a continuous process of signification which reached its turning point in 1948, the definition adopted by the World Health Organization. Currently there is no single definition about the aspirations of the standard of living that people aspire to achieve, therefore, any new definition of health must be organic, systemic, dynamic and positive. More than sixty years of the definition of health, the reality is that there are problems related to health conditions such as disability that have been measuring invariably from the biomedical model, in that sense, it seems that it is impossible to understand the disability beyond the eternal disease. Following the adoption in 2001 of the International Classification of Functioning, health and disability, opened new vistas in the field, the redirection of vision disability on expectations placed on the functioning of people and the multidirectional interactions that arise between people and context in which it operates autonomously. To do this, a conceptualization of health, which transcends the realm of the purely corporeal involving factors such representations and socio-environmental relationships are raised
Abstract
The following essay is a discussion about the possibility of conceptualizing health from disability; to do a review on current notions of health and disability was performed. [...]
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Enteroparasites paper money circulating in the shaft Barquisimeto-Cabudare, Lara State, Venezuela.
L. Valles, E. Cárdenas, G. Jaspe, M. Jaspe, K. Heredia, L. Morantes, G. Agobian

Rev Vzlana Salud Pub (2016). 16

Abstract
A descriptive, cross sectional study was carried out to examine the enteroparasite contamination of 300 banknotes of the six denominations that circulate in the Barquisimeto-Cabudare urban axis (2,5,10,20,50 and 100 BsF), through the washing of each with 100 ml of water with 20% Tween 20 for 5 minutes each side and with the aid of a sterile brush, this volume was placed in two, plastic centrifuge tubes (clean) allowed to decant for two hours , Then centrifuged at 3000 rpm for 10 minutes to observe the pellet with saline and lugol with 100X and 400X magnification. An abundance of enteroparasites was obtained in contaminated banknotes of 29% (87/300), with a diversity of four taxa. Blastocystis sp. (68 of 87 contaminated), Endolimax nana (16/87), Giardia sp. (2/87) and Entamoeba coli (1/87); Banknotes with less denomination were more contaminated than those with the highest denomination and 96,6% of the contaminated banknotes were dirty, while only 3,4% of the contaminated banknotes were clean or new banknotes. No helminth eggs were observed. It is concluded that tickets in this area are an important element (fomites) in the direct transmission of intestinal protozoa from one person to another.
Abstract
A descriptive, cross sectional study was carried out to examine the enteroparasite contamination of 300 banknotes of the six denominations that circulate in the Barquisimeto-Cabudare [...]
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Enteroparasites in residents of Almirante Padilla municipality, Zulia State, Venezuela
Á. Bracho, Z. Rivero, K. Banquet, F. Sánchez, I. Corzo, R. Atencio, R. Villalobos

Rev Vzlana Salud Pub (2016). 15

Abstract
Intestinal parasitosis are widely distributed in the world, constituting a public health problem. To evaluate whether the geographical and ecological conditions of the island municipality Almirante Padilla of Zulia State influence the prevalence of intestinal parasitosis of its inhabitants, 87 fecal samples corresponding to individuals of any age and sex were analyzed. Each sample was subjected to direct coproparasitological methods (SSF 0.85% and lugol), formalin-ether concentration method (Ritchie), Kinyoun stain and agar plate technique (Arakaki) for recovery and diagnosis Strongyloides stercoralis larvae. The prevalence of intestinal parasites in the study population was 50.57% (44/87), which prevailed monoparasitism with 52.27% (23/44). Among the parasitized individuals, 29.89% (26/87) of cases corresponded to Chromista Blastocystis sp., followed by Entamoeba complex (13.79%), Endolimax nana (13.79%) and Ascaris lumbricoides (13,79%). Strongyloides stercoralis or intestinal coccidia was not detected. The age group most affected were children aged 2 to 6 years of age (p
Abstract
Intestinal parasitosis are widely distributed in the world, constituting a public health problem. To evaluate whether the geographical and ecological conditions of the island [...]
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Propitiating psychoeducational strategies for the teacher as counselor and promoter of mental health for children and youth.
M. Hernández

Rev Vzlana Salud Pub (2016). 14

Abstract
The objective of this research focused on the design of a psychoeducational program to promote the role of the teacher as a mentor and promoter of child and adolescent mental health Estadal Basic School "Julio Teodoro Arze" of the Conception Parish Barquisimeto, Lara State. Its main purpose was to contribute to the formation of human beings I integrate mental health, able to live harmoniously in society. It was based on theoretical research and theories that support the teacher's role as counselor and promoting mental health. Methodologically, this study was framed in the modality of feasible project, contentivo of the first three phases, supported by field research of a descriptive nature. With a population of 22 teachers who were applied an instrument that measured the need for training in their role as mentor and promoter of the mental health of the child and adolescent population; it was validated by expert opinion and its reliability was established by Alfha and Cronbach reliability coefficient Kuder - Richardson obtaining high reliability. Data were analyzed using descriptive statistics. The results showed the need for a psychoeducational program to promote the role of the teacher as a mentor and promoter of mental health. The other phases of the study determined the market feasibility, technical and financial as well as program design. Finally the conclusions that led response to the objectives and recommendations for the use of the program were developed.
Abstract
The objective of this research focused on the design of a psychoeducational program to promote the role of the teacher as a mentor and promoter of child and adolescent mental [...]
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Cour years of the RVSP
L. Valles

Rev Vzlana Salud Pub (2016). 13

Abstract
The Venezuelan Public Health Magazine (RVSP) is now four years old, with eight numbers to its credit, accumulating a total of 67 articles, for an average of 8 per number; it has been a hard but comforting work, which is appreciated when seeing its fruits, where only, to mention to the technological platform of the UCLA (http://bibvirtual.ucla.edu.ve/RVSP/), they are presented more than 133,000 entries or queries, where the most widely read article has been the contamination of cabbage enteroparasitaria, with 45,000 entries, or to mention another platform such as ISSUU, where only the second number has 1937 readings, plus 28,178 impressions, according to the origin of the consultant, in order of frequency, appear Venezuela, Mexico, Spain, Peru, Ecuador, Argentina, Guatemala and the Dominican Republic, or in the case of IMBIOMED (Mexican Index of Latin American Biomedical Journals), with more than 6000 entries, auditable. All this is very pleasing because the visibility of the journal is increasing every day, which allows thousands of users who rely on RVSP to be a safe source of knowledge in Public Health.
Abstract
The Venezuelan Public Health Magazine (RVSP) is now four years old, with eight numbers to its credit, accumulating a total of 67 articles, for an average of 8 per number; [...]
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A pseudo-compressible variational multiscale solver for turbulent incompressible flows
L. Yang, S. Badia, R. Codina

Computational Mechanics (2016). Vol. 58 (6), pp. 1051-1069

Abstract
In this work, we design an explicit time-stepping solver for the simulation of the incompressible turbulent flow through the combination of VMS methods and artificial compressibility. We evaluate the effect of the artificial compressibility on the accuracy of the explicit formulation for under-resolved LES simulations. A set of benchmarks have been solved, e.g., the 3D Taylor–Green vortex problem in turbulent regimes. The resulting method is proven to be an effective alternative to implicit methods in some application ranges (in terms of problem size and computational resources), providing comparable results with very low memory requirements. As an example, with the explicit approach, we are able to solve accurately the Taylor-Green vortex benchmark in a fine mesh with 5123cells on a 12 cores 64 GB ram machine.
Abstract
In this work, we design an explicit time-stepping solver for the simulation of the incompressible turbulent flow through the combination of VMS methods and artificial compressibility. [...]
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Residual‐based stabilization of the finite element approximation to the acoustic perturbation equations for low Mach number aeroacoustics
O. Guasch, P. Sánchez-Martín, A. Pont, J. Baiges, R. Codina

Int. J. Numer. Meth. Fluids (2016). Vol. 82, pp. 839-857

Abstract
The acoustic perturbation equations (APE) are suitable to predict aerodynamic noise in the presence of a non‐uniform mean flow. As for any hybrid computational aeroacoustics approach, a first computational fluid dynamics simulation is carried out from which the mean flow characteristics and acoustic sources are obtained. In a second step, the APE are solved to get the acoustic pressure and particle velocity fields. However, resorting to the finite element method (FEM) for that purpose is not straightforward. Whereas mixed finite elements satisfying an appropriate inf–sup compatibility condition can be built in the case of no mean flow, that is, for the standard wave equation in mixed form, these are difficult to implement and their good performance is yet to be checked for more complex wave operators. As a consequence, strong simplifying assumptions are usually considered when solving the APE with FEM. It is possible to avoid them by resorting to stabilized formulations. In this work, a residual‐based stabilized FEM is presented for the APE at low Mach numbers, which allows one to deal with the APE convective and reaction terms in its full extent. The key of the approach resides in the design of the matrix of stabilization parameters. The performance of the formulation and the contributions of the different terms in the equations are tested for an acoustic pulse propagating in sheared‐solenoidal mean flow, and for the aeolian tone generated by flow past a two‐dimensional cylinder.
Abstract
The acoustic perturbation equations (APE) are suitable to predict aerodynamic noise in the presence of a non‐uniform mean flow. As for any hybrid computational aeroacoustics [...]
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A stabilized finite element method for the two-field and three-field Stokes eigenvalue problems
Ö. Türk, D. Boffi, R. Codina

Comput. Methods Appl. Mech. Engrg., (2016). Vol. 310, pp. 886-905

Abstract
In this paper, the stabilized finite element approximation of the Stokes eigenvalue problems is considered for both the two-field (displacement–pressure) and the three-field (stress–displacement–pressure) formulations. The method presented is based on a subgrid scale concept, and depends on the approximation of the unresolvable scales of the continuous solution. In general, subgrid scale techniques consist in the addition of a residual based term to the basic Galerkin formulation. The application of a standard residual based stabilization method to a linear eigenvalue problem leads to a quadratic eigenvalue problem in discrete form which is physically inconvenient. As a distinguished feature of the present study, we take the space of the unresolved subscales orthogonal to the finite element space, which promises a remedy to the above mentioned complication. In essence, we put forward that only if the orthogonal projection is used, the residual is simplified and the use of term by term stabilization is allowed. Thus, we do not need to put the whole residual in the formulation, and the linear eigenproblem form is recovered properly. We prove that the method applied is convergent, and present the error estimates for the eigenvalues and the eigenfunctions. We report several numerical tests in order to illustrate that the theoretical results are validated.
Abstract
In this paper, the stabilized finite element approximation of the Stokes eigenvalue problems is considered for both the two-field (displacement–pressure) [...]
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Variational multi-scale finite element approximation of the compressible Navier-Stokes equations
C. Bayona, J. Baiges, R. Codina

Int. J. Numer. Meth. Heat and Fluid Flows (2016). Vol. 26 (3-4), pp. 1240-1271

Abstract
Purpose The purpose of this paper is to apply the variational multi-scale framework to the finite element approximation of the compressible Navier-Stokes equations written in conservation form. Even though this formulation is relatively well known, some particular features that have been applied with great success in other flow problems are incorporated. Design/methodology/approach The orthogonal subgrid scales, the non-linear tracking of these subscales, and their time evolution are applied. Moreover, a systematic way to design the matrix of algorithmic parameters from the perspective of a Fourier analysis is given, and the adjoint of the non-linear operator including the volumetric part of the convective term is defined. Because the subgrid stabilization method works in the streamline direction, an anisotropic shock capturing method that keeps the diffusion unaltered in the direction of the streamlines, but modifies the crosswind diffusion is implemented. The artificial shock capturing diffusivity is calculated by using the orthogonal projection onto the finite element space of the gradient of the solution, instead of the common residual definition. Temporal derivatives are integrated in an explicit fashion. Findings Subsonic and supersonic numerical experiments show that including the orthogonal, dynamic, and the non-linear subscales improve the accuracy of the compressible formulation. The non-linearity introduced by the anisotropic shock capturing method has less effect in the convergence behavior to the steady state. Originality/value A complete investigation of the stabilized formulation of the compressible problem is addressed.
Abstract
Purpose The purpose of this paper is to apply the variational multi-scale framework to the finite element approximation of the compressible Navier-Stokes equations written [...]
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Concurrent finite element simulation of quadrupolar and dipolar flow noise in low Mach number aeroacoustics
O. Guasch, A. Pont, J. Baiges, R. Codina

Computers and Fluids (2016). Vol. 133, pp. 129-139

Abstract
The computation of flow-induced noise at low Mach numbers usually relies on a two-step hybrid methodolgy. In the first step, an incompressible fluid dynamics simulation (CFD) is performed and an acoustic source term is derived from it. The latter becomes the inhomogeneous term for an acoustic wave equation, which is solved in the second step, often resorting to boundary integral formulations. In the presence of rigid bodies, Curle’s acoustic analogy is probably the most extended approach. It has been shown that Curle’s boundary dipolar noise contribution does in fact correspond to the diffraction of the quadrupolar aerodynamic noise generated by the flow past the rigid body. In this work, advantage is taken from this fact to propose an alternative computational methodology to get the individual quadrupolar and dipolar contributions to the total acoustic pressure. For any linear acoustic wave operator, the unknown acoustic pressure can be split into its incident and diffracted components and be computed simultaneously to the incompressible flow field, in a single finite element computational run. This circumvents the problem found in Curle’s analogy of needing the total pressure at the body’s boundary, which includes the acoustic pressure fluctuations. The latter cannot be obtained from an incompressible CFD simulation. The proposed unified strategy could be beneficial for a large variety problems such as those involving noise generated from duct terminations, or those related with the simulation of fricatives in numerical voice production, among many others.
Abstract
The computation of flow-induced noise at low Mach numbers usually relies on a two-step hybrid methodolgy. In the first step, an incompressible fluid dynamics simulation (CFD) [...]
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A stabilized finite element method for the mixed wave equation in an ALE framework with application to diphthong production
O. Guasch, M. Arnela, R. Codina, H. Espinoza

Acta Acustica united with Acustica (2016). (preprint) Vol. 102, pp. 94-106

Abstract
Working with the wave equation in mixed rather than irreducible form allows one to directly account for both, the acoustic pressure field and the acoustic particle velocity field. Indeed, this becomes the natural option in many problems, such as those involving waves propagating in moving domains, because the equations can easily be set in an arbitrary Lagrangian-Eulerian (ALE) frame of reference. Yet, when attempting a standard Galerkin finite element solution (FEM) for them, it turns out that an inf-sup compatibility constraint has to be satisfied, which prevents from using equal interpolations for the approximated acoustic pressure and velocity fields. In this work it is proposed to resort to a subgrid scale stabilization strategy to circumvent this condition and thus facilitate code implementation. As a possible application, we address the generation of diphthongs in voice production.
Abstract
Working with the wave equation in mixed rather than irreducible form allows one to directly account for both, the acoustic pressure field and the acoustic particle velocity [...]
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Numerical Methods
C. Agelet de Saracibar, R. Boman, P. Bussetta, J. Cajas, M. Cervera, M. Chiumenti, A. Coll, P. Dadvand, J. Hernández, G. Houzeaux, M. Riera, J. Ponthot

(2016). C. Agelet de Saracibar (Ed.) in G.J. Schmitz, U. Prahl (Eds.), Handbook of Software Solutions for ICME, Chapter 7 Wiley, 632 pages, pp. 487-532

Abstract
As one of the results of an ambitious project, this handbook provides a well-structured directory of globally available software tools in the area of Integrated Computational Materials Engineering (ICME). The compilation covers models, software tools, and numerical methods allowing describing electronic, atomistic, and mesoscopic phenomena, which in their combination determine the microstructure and the properties of materials. It reaches out to simulations of component manufacture comprising primary shaping, forming, joining, coating, heat treatment, and machining processes. Models and tools addressing the in-service behavior like fatigue, corrosion, and eventually recycling complete the compilation. An introductory overview is provided for each of these different modelling areas highlighting the relevant phenomena and also discussing the current state for the different simulation approaches. A must-have for researchers, application engineers, and simulation software providers seeking a holistic overview about the current state of the art in a huge variety of modelling topics. This handbook equally serves as a reference manual for academic and commercial software developers and providers, for industrial users of simulation software, and for decision makers seeking to optimize their production by simulations. In view of its sound introductions into the different fields of materials physics, materials chemistry, materials engineering and materials processing it also serves as a tutorial for students in the emerging discipline of ICME, which requires a broad view on things and at least a basic education in adjacent fields.
Abstract
As one of the results of an ambitious project, this handbook provides a well-structured directory of globally available software tools in the area of Integrated Computational [...]
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Software Solutions for ICME
G. Schmitz, A. Engstrom, R. Bernhardt, U. Prahl, L. Adam, J. Seyfarth, M. Apel, C. Agelet de Saracibar, P. Korzhavyi, J. Agren, B. Patzak

Journal of The Minerals, Metals & Materials Society (2016). Vol. 68 (1), pp. 70-76

Abstract
The Integrated Computational Materials Engineering expert group (ICMEg), a coordination activity of the European Commission, aims at developing a global and open standard for information exchange between the heterogeneous varieties of numerous simulation tools. The ICMEg consortium coordinates respective developments by a strategy of networking stakeholders in the first International Workshop on Software Solutions for ICME, compiling identified and relevant software tools into the Handbook of Software Solutions for ICME, discussing strategies for interoperability between different software tools during a second (planned) international workshop, and eventually proposing a scheme for standardized information exchange in a future book or document. The present article summarizes these respective actions to provide the ICME community with some additional insights and resources from which to help move this field forward.
Abstract
The Integrated Computational Materials Engineering expert group (ICMEg), a coordination activity of the European Commission, aims at developing a global and open standard [...]
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Numerical modelling of landslide‐generated waves with the particle finite element method (PFEM) and a non‐Newtonian flow model
F. Salazar, J. Irazábal González, A. LARESE, E. Oñate

Int. J. Numer. Anal. Meth. Geomech. (2016). Vol. 40 (6), pp. 809-826

Abstract
Landslide‐generated impulse waves may have catastrophic consequences. The physical phenomenon is difficult to model because of the uncertainties in the kinematics of the mobilised material and to the intrinsic complexity of the fluid–soil interaction. The particle finite element method (PFEM) is a numerical scheme that has successfully been applied to fluid–structure interaction problems. It uses a Lagrangian description to model the motion of nodes (particles) in both the fluid and the solid domains (the latter including soil/rock and structures). A mesh connecting the particles (nodes) is re‐generated at every time step, where the governing equations are solved. Various constitutive laws are used for the sliding mass, including rigid solid and the Newtonian and non‐Newtonian fluids. Several examples of application are presented, corresponding both to experimental tests and to actual full‐scale case studies. The results show that the PFEM can be a useful tool for analysing the risks associated with landslide phenomena, providing a good estimate to the potential hazards even for full‐scale events.
Abstract
Landslide‐generated impulse waves may have catastrophic consequences. The physical phenomenon is difficult to model because of the uncertainties in the kinematics of the [...]
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Interpretation of dam deformation and leakage with boosted regression trees
F. Salazar, M. Toledo, E. Oñate, B. Suarez

Engineering Structures (2016). (Preprint) Vol. 119, pp. 230-251

Abstract
Predictive models are essential in dam safety assessment. They have been traditionally based on simple statistical tools such as the hydrostatic-season-time (HST) model. These tools are well known to have limitations in terms of accuracy and reliability. In the recent years, the examples of application of machine learning and related techniques are becoming more frequent as an alternative to HST. While they proved to feature higher flexibility and prediction accuracy, they are also more difficult to interpret. As a consequence, the vast majority of the research is limited to prediction accuracy estimation. In this work, one of the most popular machine learning techniques (boosted regression trees), was applied to model 8 radial displacements and 4 leakage flows at La Baells Dam. The possibilities of model interpretation were explored: the relative influence of each predictor was computed, and the partial dependence plots were obtained. Both results were analysed to draw conclusions on dam response to environmental variables, and its evolution over time. The results show that this technique can efficiently identify dam performance changes with higher flexibility and reliability than simple regression models.
Abstract
Predictive models are essential in dam safety assessment. They have been traditionally based on simple statistical tools such as the hydrostatic-season-time (HST) model. These [...]
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Numerical modeling of the electron beam welding and its experimental validation
M. Chiumenti, M. Cervera, N. Dialami, B. Wu, L. Jinwei, C. Agelet de Saracibar

Finite Elements in Analysis and Design (2016). (preprint) Vol. 121, pp. 118–133

Abstract
Electron Beam Welding (EBW) is a highly efficient and precise welding method increasingly used within the manufacturing chain and of growing importance in different industrial environments such as the aeronautical and aerospace sectors. This is because, compared to other welding processes, EBW induces lower distortions and residual stresses due to the lower and more focused heat input along the welding line. This work describes the formulation adopted for the numerical simulation of the EBW process as well as the experimental work carried out to calibrate and validate it. The numerical simulation of EBW involves the interaction of thermal, mechanical and metallurgical phenomena. For this reason, in this work the numerical framework couples the heat transfer process to the stress analysis to maximize accuracy. An in-house multi-physics FE software is used to deal with the numerical simulation. The definition of an ad hoc moving heat source is proposed to simulate the EB power surface distribution and the corresponding absorption within the work-piece thickness. Both heat conduction and heat radiation models are considered to dissipate the heat through the boundaries of the component. The material behavior is characterized by an apropos thermo-elasto-viscoplastic constitutive model. Titanium-alloy Ti6A14V is the target material of this work. From the experimental side, the EB welding machine, the vacuum chamber characteristics and the corresponding operative setting are detailed. Finally, the available facilities to record the temperature evolution at different thermo-couple locations as well as to measure both distortions and residual stresses are described. Numerical results are compared with the experimental evidence.
Abstract
Electron Beam Welding (EBW) is a highly efficient and precise welding method increasingly used within the manufacturing chain and of growing importance in different industrial [...]
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Explicit mixed strain-displacement finite elements for compressible and quasi-incompressible elasticity and plasticity
M. Cervera, N. Lafontaine, R. Rossi, M. Chiumenti

Computational Mechanics (2016). (Preprint) Vol. 58 (3), pp. 511–532

Abstract
This paper presents an explicit mixed finite element formulation to address compressible and quasi-incompressible problems in elasticity and plasticity. This implies that the numerical solution only involves diagonal systems of equations. The formulation uses independent and equal interpolation of displacements and strains, stabilized by variational subscales. A displacement sub-scale is introduced in order to stabilize the mean-stress field. Compared to the standard irreducible formulation, the proposed mixed formulation yields improved strain and stress fields. The paper investigates the effect of this enhancement on the accuracy in problems involving strain softening and localization leading to failure, using low order finite elements with linear continuous strain and displacement fields (P1P1 triangles in 2D and tetrahedra in 3D) in conjunction with associative frictional Mohr–Coulomb and Drucker–Prager plastic models. The performance of the strain/displacement formulation under compressible and nearly incompressible deformation patterns is assessed and compared to analytical solutions for plane stress and plane strain situations. Benchmark numerical examples show the capacity of the mixed formulation to predict correctly failure mechanisms with localized patterns of strain, virtually free from any dependence of the mesh directional bias. No auxiliary crack tracking technique is necessary.
Abstract
This paper presents an explicit mixed finite element formulation to address compressible and quasi-incompressible problems in elasticity and plasticity. This implies that [...]
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High-fidelity prediction of crack formation in 2D and 3D pullout tests
L. Benedetti, M. Cervera, M. Chiumenti

Computers and Structures (2016). (preprint) Vol. 172, pp. 93–109

Abstract
This paper presents the 2D and 3D numerical analysis of pullout tests on steel anchorages in concrete blocks using standard and mixed finite elements. A novel (stabilized) mixed formulation in the variables of total strain ε and displacements u is introduced to overcome the intrinsic deficiencies of the standard displacement-based one in the context of localization of strains, such as mesh dependency. The quasi-brittle behavior of concrete is described through an elastoplastic constitutive law with a local Rankine yielding criterion. The proposed formulation is shown to be a reliable and accurate tool, sensitive to the physical parameters of the pullout tests, but objective with respect to the adopted FE mesh. Furthermore, the mixed ε/u finite element is able to capture the correct failure mechanism with relatively coarse discretizations. At the same time, the spurious behavior of the standard formulation is not alleviated by mesh-refinement.
Abstract
This paper presents the 2D and 3D numerical analysis of pullout tests on steel anchorages in concrete blocks using standard and mixed finite elements. A novel (stabilized) [...]
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Analysis of the effect of provisional ties in the construction and current deformation of Mallorca cathedral
L. Pelà, J. Bourgeois, P. Roca, M. Cervera, M. Chiumenti

International Journal of Architectural Heritage (2016). (preprint) Vol. 10 (4), pp. 418–437

Abstract
This article presents the analysis of the structure of Mallorca Cathedral taking into account the influence on the structural behavior of auxiliary iron ties used during the construction process. Recent studies (Roca et al. 2012, 2013) presented some hypotheses about the construction process of the cathedral. This article complements the previous results by considering the use of auxiliary ties as temporary stabilizing device during the construction. Evidence of the use of ties during the construction has been recognized after a comprehensive survey. The study of the role of such ties and the effect of their later removal are studied by a FE analysis carried out on a representative bay of the structure. The study includes a time-dependent FE analysis after the removal of the ties to assess the long-term structural behavior. The results of the numerical analysis are compared with the deformation trends identified by means of a recent monitoring campaign.
Abstract
This article presents the analysis of the structure of Mallorca Cathedral taking into account the influence on the structural behavior of auxiliary iron ties used during the [...]
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A thermodynamically consistent plastic-damage framework for localized failure in quasi-brittle solids: Material model and strain localization analysis
J. Wu, M. Cervera

Int. J. Solids and Structures (2016). (preprint) Vol. 88–89, pp. 227–247

Abstract
Aiming for the modeling of localized failure in quasi-brittle solids, this paper addresses a thermodynamically consistent plastic-damage framework and the corresponding strain localization analysis. A unified elastoplastic damage model is first presented based on two alternative kinematic decompositions assuming infinitesimal deformations, with the evolution laws of involved internal variables characterized by a dissipative flow tensor. For the strong (or regularized) discontinuity to form in such inelastic quasi-brittle solids and to evolve eventually into a fully softened one, a novel strain localization analysis is then suggested. A kinematic constraint more demanding than the classical discontinuous bifurcation condition is derived by accounting for the traction continuity and the loading/unloading states consistent with the kinematics of a strong (or regularized) discontinuity. More specifically, the strain jumps characterized by Maxwell’s kinematic condition have to be completely inelastic (energy dissipative). Reproduction of this kinematics implies vanishing of the aforesaid dissipative flow tensorial components in the directions orthogonal to the discontinuity orientation. This property allows naturally developing a localized plastic-damage model for the discontinuity (band), with its orientation and the traction-based failure criterion consistently determined a posteriori from the given stress-based counterpart. The general results are then particularized to the 2D conditions of plane stress and plane strain. It is found that in the case of plane stress, strain localization into a strong (or regularized) discontinuity can occur at the onset of strain softening. Contrariwise, owing to an extra kinematic constraint, in the condition of plane strain some continuous inelastic deformations and substantial re-orientation of principal strain directions in general have to take place in the softening regime prior to strain localization. The classical Rankine, Mohr–Coulomb, von Mises (J2) and Drucker–Prager criteria are analyzed as illustrative examples. In particular, both the closed-form solutions for the discontinuity angles validated by numerical simulations and the corresponding traction-based failure criteria are obtained.
Abstract
Aiming for the modeling of localized failure in quasi-brittle solids, this paper addresses a thermodynamically consistent plastic-damage framework and the corresponding strain [...]
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Modelling of Bingham and Herschel–Bulkley flows with mixed P1/P1 finite elements stabilized with orthogonal subgrid scale
E. Moreno, A. LARESE, M. Cervera

Journal of Non-Newtonian Fluid Mechanics (2016). (preprint) Vol. 228, pp. 1-16

Abstract
This paper presents the application of a stabilized mixed pressure/velocity finite element formulation to the solution of viscoplastic non-Newtonian flows. Both Bingham and Herschel–Bulkley models are considered. The detail of the discretization procedure is presented and the Orthogonal Subgrid Scale (OSS) stabilization technique is introduced to allow for the use of equal order interpolations in a consistent way. The matrix form of the problem is given. A series of examples is presented to assess the accuracy of the method by comparison with the results obtained by other authors. The extrusion in a Bingham fluid and the movement of a moving and rotating cylinder are analyzed in detail. The evolution of the streamlines, the yielded and unyielded regions, the drag and lift forces are presented. These benchmark examples show the capacity of the mixed OSS formulation to reproduce the behavior of a Bingham and Herschel–Bulkley flows with the required accuracy.
Abstract
This paper presents the application of a stabilized mixed pressure/velocity finite element formulation to the solution of viscoplastic non-Newtonian flows. Both Bingham and [...]
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Agenda
-. EPI

El profesional de la información (2016). Vol. 25, (1), 114

Abstract
Jornadas,
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OCLC EMEARC 2016: reflexiones en torno al futuro de las tecnologías y las bibliotecas
R. Eíto-Brun

El profesional de la información (2016). Vol. 25, (1), 113

Abstract
Los
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