Scipedia: Documents published in 2023

Coupled Spatio-Temporal Dynamics and Nonlocality in Advanced Mathematical Models for the Analysis of Complex Neurodegenerative Disease Pathologies

Jesús Sánchez Pinedo — Thu, 02 Nov 2023 10:54:10 +0100

One in six of the world’s population has to deal with neurodegenerative disorders, and while medical devices exist to detect, prevent, and treat such disorders, some fundamentals of the progression of associated diseases remain ambiguous. In this contribution, we focus on Alzheimer’s disease (AD), where amyloid-beta (Aβ) and tau proteins are among the main contributors to the development or propagation of AD. The Aβ proteins clump together to form plaques and disrupt cell functions. Moreover, the abnormal chemical change in the brain helps to build sticky tau tangles that block the neuron’s transport system. Astrocytes generally maintain a healthy balance in the brain by clearing the Aβ toxic plaques. Even so, over-activated astrocytes release chemokines and cytokines and also react to pro-inflammatory cytokines, further increasing the production of Aβ. We have provided details of a novel coupled mathematical model that can capture astrocytes’ dual behaviour, emphasizing the importance of spatio-temporal coupling and nonlocality. We have demonstrated that the disease propagation depends on memory effects, that is the disease’s earlier status, which involves non-Markovian processes. We have explained how to integrate brain connectome data in the network model and to study this effect, as well as the dual role of astrocytes as a coupled phenomenon. Depending on toxic loads in the brain, we have also discussed details of the analysis of the neuronal damage in the brain. We have explained how the memory effect can slow down the propagation of toxic proteins in the brain, decreasing the rate of neuronal damage. Representative numerical examples have been given, and special attention has been paid to nonequilibrium considerations and stochastic modelling frameworks in the study of neurodegenerative diseases.

Development of an FSI Environment for the Aerodynamic Performance Assessment of Flapping Wings

Jesús Sánchez Pinedo — Thu, 02 Nov 2023 10:40:48 +0100

Insects and birds take advantage of their flexible wings to modulate the aerodynamic forces and increase their flight efficiency. A deep understanding of the aeroelastic benefits could be valuable to design Flapping Wing Micro Air Vehicles (FWMAVs) that exploit nature’s full potential. This work presents an open-source, high-fidelity, Fluid-Structure Interaction solver (FSI) to simulate flapping and deforming wings. The proposed approach uses the code CoCoNuT to couple the Computational Structural Mechanics (CSM) software Kratos Multiphysics with the Computational Fluid Dynamics (CFD) software OpenFOAM. The coupling code relies on the Interface Quasi-Newton with Inverse Jacobian method (IQNI). The CSM evaluates the wing deformation using a classic Finite Element Method with shell elements, while the CFD solver uses the deformable overset method. In the CFD solver, the deformation of the wing is interpolated onto the grid’s boundaries to accurately simulate wings with large motion and deformation. The FSI solver is tested in the case of an airfoil in heave motion and validated with experimental data. The results demonstrate the strong influence of wing deformation on its aerodynamic performance

A numerical approach for the characterization of the free-fall dynamics of thin disks

Jesús Sánchez Pinedo — Thu, 02 Nov 2023 10:36:52 +0100

This study focuses on investigating numerically the dynamics of thin disks freely falling inside viscous and incompressible fluids. We solve the model by using the finite element method and the main falling modes are identified using the Reynolds number and dimensionless inertia moment. The results are mapped in a phase diagram for comparison with existing literature and validation of the simulations. The effect of introducing a hole in the disk geometry is investigated, analyzing variations in trajectories and Strouhal numbers. Furthermore, falling styles are quantified by examining the fluctuations of the orientation of the axis of the disks over time. Additionally, a quantitative analysis of the solid body velocities for the fluttering and tumbling modes highlights the significant differences between them. The study successfully characterizes the main falling modes through qualitative and quantitative analyses.

Efficient numerical methods for simulating cardiac electrophysiology with cellular resolution

Jesús Sánchez Pinedo — Thu, 02 Nov 2023 10:33:49 +0100

The cardiac extracellular-membrane-intracellular (EMI) model enables the precise geometrical representation and resolution of aggregates of individual myocytes. As a result, it not only yields more accurate simulations of cardiac excitation compared to homogenized models but also presents the challenge of solving much larger problems. In this paper, we introduce recent advancements in three key areas: (i) the creation of artificial, yet realistic grids, (ii) efficient higher-order time stepping achieved by combining low-overhead spatial adaptivity on the algebraic level with progressive spectral deferred correction methods, and (iii) substructuring domain decomposition preconditioners tailored to address the complexities of heterogeneous problem structures. The efficiency gains of these proposed methods are demonstrated through numerical results on cardiac meshes of different sizes.

Multiphysics Numerical Investigations of Hot Components in a sCO2 Power Plant Turbine

Jesús Sánchez Pinedo — Thu, 02 Nov 2023 10:29:13 +0100

To achieve a higher energy conversion efficiency, the use of supercritical CO2 (sCO2) in closed-loop Brayton and Rankine cycles has become relevant in the last decades due to an increased interest in its properties. sCO2 allows a more efficient heat transfer, chemical stability, non-flammability, and greater system efficiency. The necessity of a sealing system, which creates a barrier between the high-pressure fluid in the turbine and compressor and low-pressure regions, became essential for high-efficiency preservation and plant emissions reduction. In this regard, Dry Gas Seals (DGS) become one of the substantial components for sCO2 turbomachinery design due to lower leakage and higher efficiency than a traditional labyrinth radial seal. The high fluid pressure and density, connected to a small size sealing clearance and a high rotational speed, results in a significant friction heat, which characterizes the domain temperature distribution. The necessity for a thermal analysis of the domain becomes compelling to respect the maximum temperatures allowed in the turbomachine. When drawing up a thermal analysis, the high computational costs of a 3D simulation of the fluid domain (CFD) could be unfavourable due to the different orders of magnitude of secondary flows cavity sizes and DGS seals gaps, and the necessity to run a high number of simulations to define a geometrical sensitivity and optimization of crucial zones. A segregated conjugate heat transfer (CHT) iterative procedure has been implemented, relating a commercial 1D fluid modeller (Altair Flow Simulator) and a commercial finite element solver (Ansys Mechanical). To assess the procedure developed, 3D CFD simulations and CHT analysis of specific critical areas of the domain have been carried out. The segregated approach, implemented within the European project CO2OLHEAT, showed results in line with 3D CFD and CHT analysis, reducing computational time and cost.

The effect of inherent nonlinearities in coupled piezo-magneto-electric vibration energy harvester

Jesús Sánchez Pinedo — Thu, 02 Nov 2023 10:15:10 +0100

Accelerating the FlowSimulator: Improvements in FSI Simulations for the HPC Exploitation at Industrial Level

Jesús Sánchez Pinedo — Thu, 02 Nov 2023 10:00:34 +0100

Influencia de los factores socioeconómicos en la mortalidad por COVID-19 en México

Vanessa Soulé — Sun, 29 Oct 2023 17:39:03 +0100

La pandemia por el virus SARS-CoV-2 mostró la necesidad de realizar estudios multidisciplinarios que ayudaran a entender el riesgo de mortalidad por COVID-19. En este trabajo se buscó determinar la influencia de los factores socioeconómicos que existían dentro de la población mexicana mediante la aplicación del modelo de regresión lineal múltiple, para esto el análisis se hizo a nivel municipal en las 3 primeras olas de la pandemia, definiendo grupos poblacionales homogéneos para identificar cuáles son los factores socioeconómicos que tienen mayor influencia y nos ayudan a describir el riesgo de fallecer por COVID-19 en México.

Tendencias actuales en los recursos humanos

Paola Barrera — Sat, 28 Oct 2023 02:05:03 +0200

New trends in human resource management include human talent management, focus on job performance, recruitment of qualified candidates,andemployeeperformance evaluation. Today, there is a growing adoption of cutting-edge technologies in the field of humancapitalmanagement.These technologies include artificial intelligence, data analytics, process automation and cloud platforms. One of the most prominent trends is the use of artificial intelligence and machine learning to improve efficiency and decision making in humancapitalmanagement.These technologies make it possible to analyze large amounts of data to identify patterns and trends, which helps HR professionals make more informed and strategic decisions. Anotherimportanttrendisprocess automation. More and more organizations are adopting systems and tools that automate repetitive and administrative tasks, such as payrollmanagement,recruitingand performance tracking. This frees up time for HR professionals to focus on more strategic activities, such as talent development and succession planning.

¿La obesidad tiene consecuencias en el desarrollo físico a causa del sedentarismo?

Francisco Ramos — Fri, 27 Oct 2023 07:27:03 +0200

La obesidad es una enfermedad crónica compleja con múltiples factores causales, incluyendo genéticos, sociales y de estilo de vida. Se caracteriza por aumento en los depósitos de grasa debido a un desequilibrio entre la ingesta de energía y el gasto energético, resultando un aumento de peso. Este desequilibrio es la causa de la obesidad.

La obesidad tiene consecuencias para la salud, incluyendo un mayor riesgo de desarrollar diabetes tipo 2, hipertensión arterial, enfermedades cardiovasculares y varios tipos de cáncer. Además, la obesidad conlleva estigmatización social y, en algunas sociedades, se asocia con menores ingresos laborales, especialmente en mujeres. Los costos directos e indirectos de la obesidad ejercen una presión significativa sobre los sistemas de atención médica y requieren una acción urgente basada en la evidencia científica para la prevención y control.

Desde una perspectiva económica, se estima que la obesidad tiene un alto costo. En 2008, se calculó que el costo anual en atención médica directa para el sistema de salud público, derivado de complicaciones asociadas con la obesidad, ascendía a 42,000 millones de pesos. Además, se estimó un costo indirecto por pérdida de productividad de 25,000 millones de pesos en el mismo año. En total, los costos directos e indirectos de la obesidad en 2008 se situaron en 67,000 millones de pesos. Para 2017, se proyecta que los costos directos oscilen entre 78,000 y 101,000 millones de pesos, y los costos indirectos entre 73,000 y 101,000 millones de pesos, si las medidas gubernamentales actuales no generan un impacto significativo.

Dentro del resumen se pueden apreciar palabras calves que serán útiles para la investigación, las cuales son: genéticos, obesidad, energía, sociedad y finalmente cardiovascular.

Algoritmo no supervisado para la segmentación de imágenes digitales de micrografías de nanopartíclas de plata (Ag).

Adianez Arhely Gamboa Rivas — Thu, 26 Oct 2023 20:33:05 +0200

La segmentación de imágenes es un tipo específico de agrupamiento de datos. El agrupamiento en este contexto es conocer grupos de píxeles en las imágenes para obtener información relevante que por lo general se encuentra implícita en ellas. La Microscopía Electrónica de Transmisión (MET o TEM, por Transmission Electron Microscopy) es un una técnica experimental y de alto costo monetario, en la que un haz de electrones suficientemente acelerado colisiona con una muestra (nanopartículas de plata (Ag) en este caso) delgada convenientemente preparada. En la muestra los electrones colisionan con respecto a algunas propiedades específicas (grosor y tipo de átomos), todo este proceso forma una imagen digital con distintas intensidades de gris que corresponde al grado de dispersión de los electrones incidentes. Propiedades como la cantidad y el diámetro de nanopartículas existentes en este tipo de imágenes es relevante conocer de forma automatizada, ya que por lo general conocer este tipo de propiedades se hace mediante procedimientos laboriosos. Sin embargo, analizar este tipo de imágenes utilizando algoritmos no supervisados simplifica este tipo de trabajo, pero implica enfrentarse al problema de alta densidad de pixeles existentes en ellas. El algoritmo KMeans es del tipo no supervisado y utilizado para hacer segmentación de píxeles en imágenes de micrografías como lo indican algunos autores y que en este trabajo en etapa inicial es utilizado para contabilizar y obtener el diámetro de nanopartículas de plata (Ag) que son las imágenes con las que se cuenta hasta el momento y son el resultado del grupo de trabajo experimental de la División de Ciencias e Ingeniería de la Universidad de Guanajuato Campus León. Para llevar a cabo todo el procesamiento computacional se utilizará una computadora de nueva generación llamada Parallella que es un proyecto de bajo costo monetario, poco consumo energético y diseñado para el alto desempeño de cálculo numérico, siendo estas características una opción que beneficiará a este proyecto por no contar con infraestructura computacional adecuada.

El algoritmo KMeans y el problema de los centroides iniciales

Gael Antonio Torres Aguirre — Thu, 26 Oct 2023 19:51:06 +0200

El gran volumen de datos en el que se vive en la actualidad, hace evidente la necesidad de clasificar los datos para obtener relaciones, asociaciones y correlaciones de ellos. Para llevar a cabo esta clasificación es necesario emplear algoritmos de agrupamiento del tipo no supervisado y particionales. Un candidato de este tipo es el algoritmo KMeans, ampliamente utilizado para resolver el problema de agrupamiento. Sin embargo, este algoritmo necesita de argumentos iniciales como lo son el número de grupos y un conjunto de datos llamados centroides que son los representantes de cada uno de ellos. Esto puede ser una fortaleza pero a la vez puede representar limitaciones del algoritmo. Es por ello que en este trabajo se inicia con la caracterización general del algoritmo KMeans en base a la selección de los centroides iniciales para después estudiar la técnica de análisis de componentes principales y con esta proporcionar centroides iniciales óptimos, pero esa etapa aún está en desarrollo y por tanto solo se presenta la idea inicial. La herramienta computacional es clave para el trabajo con alta densidad de datos es por eso que en este trabajo también se tiene como objetivo implantar un marco de trabajo llamado Apache Spark.

Simulación numérica sobre el efecto del plasmón localizado de nanopartículas de plata (Ag), bajo el marco de la teoría de Mie

José Luis Fraga Almanza — Thu, 26 Oct 2023 19:08:39 +0200

Las nanopartículas (Nps) de metales nobles como plata (Ag) y oro (Au) en las últimas décadas son objeto de extensa investigación en el contexto de las nanociencias y la nanotecnología, principalmente esto se debe a sus propiedades ópticas únicas. En las Nps, el gas de electrones libres en ellas presenta propiedades de oscilación resonante, fenómeno conocido como el plasmón superficial localizado (PSL). Al irradiarse las Nps en el ultravioleta y visible del espectro, la absorción óptica, depende fundamentalmente del material constitutivo, la geometría de la Nps y su entorno. La dispersión de la radiación electromagnética de una esfera, es definida por la Teoría de Mie. Los cálculos al usar esta teoría pueden llegar a ser largos e incluso imposibles para aquellos con recursos hardware limitados. Por lo tanto en esta investigación que actualmente, se encuentra en desarrolló, se diseño e implanto una simulación numérica escrita en Python 3 para la obtención de los coeficientes de Mie en nanopartículas de plata (Ag) y contar con una herramienta computacional que generé escenarios permitiendo el estudio y obtención de los coeficientes de extinción de NPs de Ag, siendo esta metodología fácilmente adaptable para otros metales donde se pueden calcular y/o simular una variedad de propiedades ópticas.

Construction of a global vector autoregression with trade and financial relationships between countries and forecasting of Russian macroeconomic indicators

Elisaveta Grebennikova — Thu, 26 Oct 2023 11:26:04 +0200

The purpose of this research is to analyze the impact of external shocks on the Russian economy and build forecasts for the dynamic of Russian macroeconomic variables within the framework of a global vector autoregression model. In this study, special attention is focused on including channels for transmitting not only real but also financial shocks into the model by using different weights for aggregating variables. Also, the model for the Russian economy has been expanded by including not only variables of the real sector, but also indicators of the inflation rate and interest rate. The results provide impulse response functions for Russian indicators in response to a US interest rate shock.

La Reinserción Social en el Estado de Querétaro

Oscar Ledezma — Thu, 26 Oct 2023 04:47:03 +0200

Esta investigación se enfoca en la reinserción social de individuos privados de libertad en México, destacando su relevancia en el sistema penitenciario y la sociedad en general. Se definen conceptos clave, como la reinserción social, la diferencia entre cárcel y presidio, y la delincuencia. Los programas de reinserción se presentan como elementos cruciales para prevenir la reincidencia delictiva y promover la rehabilitación de aquellos que han transgredido la ley. Se adopta la Teoría de la Prevención como marco conceptual, que enfatiza la importancia de prevenir la reincidencia a través de la educación y la promoción de valores positivos. Además, se emplea el método de la Teoría Fundamentada, que se basa en la construcción de teorías a partir de datos recopilados de manera sistemática. Se describen las técnicas de descripción, ordenamiento conceptual y teorización como herramientas esenciales en la investigación. En resumen, esta investigación resalta la necesidad de una cultura de prevención en los programas de reinserción social en México para mejorar su efectividad y reducir los costos del sistema penitenciario. La reinserción exitosa no solo beneficia a los individuos que han cometido delitos, sino que también contribuye a la seguridad y el bienestar de la sociedad en general al reducir la delincuencia y fomentar la reintegración de ex delincuentes como miembros productivos de la comunidad.

ESTIMATES OF DISTORTIONS OF THE ECONOMIES OF THE EAEU COUNTRIES FROM EXISTING NON-TARIFF BARRIERS» (first stage)

Elisaveta Grebennikova — Wed, 25 Oct 2023 10:29:06 +0200

Inevitably, non-tariff barriers (NTBs) that exist in trade between countries generate rents associated with them, which can either be distributed in some ratio between trading partners or dissipate, thereby leading to a loss of resources. The valuation of these rents and their distribution is not an easy task, because the effect of NTBs in their entirety is usually difficult to quantify due to the different nature of the trade restrictions that make up NTBs. Nevertheless, in the light of the global trend towards tariff liberalization that has been going on for more than a hundred years, this task sometimes becomes more important in the study of trade than classical studies of the impact of import and/or export tariffs, since NTB rents can multiply tariff revenue. One of the possible tools for modeling the impact of NTBs on the economies of various countries (and in particular on the domestic prices of goods), taking into account the existing trade relations between states, are static CGE trading models (from the English Computable General Equilibrium models computable general equilibrium models). One of the objectives of this study is to prepare our own database based on the most recent available statistical data, similar in structure to the GTAP 10 database, but with a smaller number of regions and supplemented with information about the ad valorem equivalents of the goods we are interested in in the context of trading partners. As the results in this study, the following aspects of the work carried out can be distinguished, such as a review of the literature on existing approaches to assessing the imbalances of economies generated by NTM, as well as an analysis of trade in goods and services between the EAEU countries and their main partners, which is necessary for interpreting the results of the numerical modeling stage, a scheme for preparing input data for calibration of the used CGE models.

Russia-CIS co-operation development in the context of world economic structural transformation. (Part I)

Elisaveta Grebennikova — Wed, 25 Oct 2023 09:55:03 +0200

The first part of the research studies theoretical approaches, models and factors in determining the structural transformation of the world economy and presents some empirical assessments. The object of this study is trade and economic cooperation of the CIS countries in the context of structural transformation of the world economy and new trade and political restrictions introduced against Russia and Belarus, which have a significant impact on the entire system of foreign economic relations. The aim of the study is to assess the changes in the level of integration in different spheres of Russia, the EU, China with the CIS countries and CIS countries among themselves and the impact of sanctions against Russia and Belarus on the CIS countries. The relevance of the work is justified by the transformation of economic ties of the CIS countries, the forced need for Russia to search for new international transport and logistics routes and financial schemes and the processes of transformation of the system of international economic relations, which together form a new economic reality for the CIS. The paper uses an empirical method of quantitative data research, econometric method of calculating various indicators and indices, as well as systemic analysis. The main results of the study consist in analyzing changes in the conditions of trade and economic cooperation of post-Soviet countries and integration in different spheres in 2022, including interrupted projects, including those with third countries.

PROSPECTS FOR THE DEVELOPMENT OF THE LONGEVITY ECONOMY IN THE REGIONS OF RUSSIA

Elisaveta Grebennikova — Mon, 23 Oct 2023 09:37:03 +0200

The relevance of the work is justified by the fact that it is devoted to the rapidly developing sector of the economy associated with the needs of the older generation. The growth of this sector is associated with the global trend of population aging. The subject of the study is the comparative level of the quality of life of senior citizens and the potential for the development of the longevity economy in the regions of Russia. Purpose of work: a comprehensive study of the factors and evaluation of the prospects for the development of the longevity economy in the regions of Russia and development of priority areas of regional policy. To achieve the goal, the following tasks were undertaken: analysis of scientific approaches to the study of the factors of formation and assessment of the prospects of the «longevity economy at the national and regional levels in the framework of foreign and domestic experience; development of an approach to a comprehensive assessment of factors and prospects for the development of the longevity economy in the regions of the Russia, taking into account the specifics of national and regional statistics; analysis of demographic, social and economic factors in the formation of the longevity economy and assessment of the prospects for its development in the regions of the Russia; a typology of the regions of the Russia in accordance with the assessment of the prospects for the development of the longevity economy; development of proposals on the priorities of regional policy, taking into account the course on import substitution in the conditions of sanctions pressure and the obtained estimates of the prospects for the development of the longevity economy in the regions of Russia. The scientific novelty of the work is determined by the justification of the typology of Russian regions on the basis of the developed integral quality of the older generation life index and the prospects for the development of the longevity economy. Research methods applied: system, factor and statistical analysis of sectoral development, index method, etc. Based on the application of the author's approach, several Russian regions that need additional federal support to improve the older generation life quality and to develop a longevity economy were identified. Priority measures of regional policy have been developed for such regions. The application of the authors’ approach is recommended for information and methodological support of the state regional policy of Russia and increasing of its effectiveness.

Evaluation of Brain Signal Amplifier Circuit Performance by Polymer Biosensor in Portable Neurological Patient Monitoring System

Reyhaneh Rahimi — Mon, 23 Oct 2023 09:04:03 +0200

Increasing the flexibility of electrodes by using flexible biocompatible biopolymer substrates as well as using conductive polymers with suitable electrical conductivity such as (PEDOT: PSS) instead of metallic base materials in the electrode channels has greatly contributed to this goal. But the next step is to increase the amplitude of the touched signal by the electrode in an amplifier circuit by suitable gain factor. Therefore, in the present study an electrical biosensor consisting of a 64-channel microelectrode with intra-structural amplification capability, external circuit precision for amplification of sensible brain signals on scale has been studied. Thereafter, the polymer biosensor to be integrated into a dry and portable monitoring system for monitoring neurologic disorders and identification of focal seizures symptoms e.g. in aura state for epilepsy. This has allowed by achieving a precise signal on scale even with a dry multichannel electrode, without no electrolyte gel between the surface of the electrode and the skin. Although, localization of the electrode is restricted, due to the importance of touching the prone signals in the frontal and partial lobes, it has been attempted to place the electrode on the frontal area to increase both signal sensibility and processing. Moreover, the error of muscle movements in frontal lobe is reduced by locating electrode in frontal-partial (FP) position to achieve a signal that overlapping both lobes to predicting seizure symptoms more accurately. This set-up has been successfully tested on patients, and along with the designed interface circuit, using an open-source oscillography application, signal touching has also been accomplished by an Android-based mobile phone.

Research on seismic performance of corrugated web rigid structures

cao huimin — Sat, 21 Oct 2023 09:41:02 +0200

Corrugated steel refers to steel that is wavy along the length direction and is widely used in beams, columns, walls, and other parts of building structures. It plays a connecting and supporting role. The wavy or folded shape of the web plate to some extent improves the shear instability ability and out-of-plane stiffness of the web plate. Industrial factories often use corrugated web H-shaped steel components. However, although corrugated web H-shaped steel components have the advantages of high strength, high stiffness, lightweight, and convenient construction, relevant regulations indicate that these components can only be used for lower intensities or higher intensities when certain conditions are met, One important condition is that the ratio of the design value of axial force including seismic action to the product of the cross-sectional area of the component flange and the design value of steel tensile strength should not exceed 0.4. In this regard, this article will further explore the seismic characteristics and applicable intensity of H-shaped steel structures with corrugated web plates under earthquake action through large-scale finite element ABAQUS simulation. The dynamic characteristics and failure situation of corrugated rigid frame structures will be observed through the elastic-plastic time history analysis method, and the plastic deformation characteristics of steel beam members will be observed by applying low-cycle repeated loads through the hysteresis analysis method. The research shows that under reasonable design conditions, Corrugated web H-shaped steel structural components can be appropriately increased in axial compression ratio for use in high-intensity areas.

Failure of ETFE Film Membrane

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 12:27:26 +0200

Plektotonik - Structural textile membrane from fast growing and formable trees (SRC)

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 12:18:13 +0200

Architecture for pigs

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 12:17:57 +0200

Biogas production has the potential to provide three benefits for green energy, waste management, and bio-fertilizers. The process involves converting organic waste materials, such as agricultural waste and food scraps, into methane-rich biogas through anaerobic digestion. This biogas can then be used to generate electricity and heat, reducing the reliance on fossil fuels. Additionally, the waste materials are broken down, reducing the amount of waste in landfills, and the process produces nutrient-rich fertilizer for crops. In summary, biogas production can play a significant role in creating a sustainable future. In recent decades, membrane materials have been used and improved to become a proven solution for covering the roof of anaerobic digesters. Coated textiles, with advanced technical properties such as good gas barrier properties, flexibility, and durability, are ideal for this application. The aim of this paper is to provide the reader with a clear understanding of biogas production and the focus on the impact of some plasticizers which can be used for the development of a gas membrane in anaerobic digesters.

ATLAS architectural membrane as a core element for larger and energy efficient air domes

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 12:17:43 +0200

A Numerical Technique for Modelling Hypersonic Inflatable Shields

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:54:01 +0200

This paper describes a recently developed numerical technique to simulate high-speed flows on complex 3D inflatable structures using tetrahedral volume grids. In detail, the proposed methodology is based on the front-tracking approach, as it involves the coupling between a shock-fitting technique and a non-linear structural solver: by doing so, we are able to exploit the well-known advantages of shock-fitting regarding the computation and modelling of gas-dynamic discontinuities to deal with fluid-structure interaction problems. More details about the proposed technique and some applications to inflatable structures in hypersonic flows are presented in this paper

Short-term Prediction of Wind Speed based on Frequency Decomposition and ANN

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:53:04 +0200

Investigating wind loading for standardizing purposes on representative double-curved freestanding membrane roof canopies

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:52:38 +0200

The effect of prestress levels and of geometric scale on the aeroelastic behaviour of double-curved membrane roofs

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:52:09 +0200

Towards Embedded Fluid-Structure Interaction Simulations Based on CAD-Integrated Thin-Walled Structures

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:51:42 +0200

Simulation Calibration Of Differentiated Knitted Membranes With Evolutionary Optimisation Tools

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:46:24 +0200

Knit, with its inherent flexibility and ability to integrate bespoke material performance, creates a promising alternative to traditionally woven membranes in architectural textile applications. The CNC-knitting technology allows for the manufacturing of membranes with gradient expansion properties by numerically controlling the distribution of varied stitches. In architectural knitted structures, material programming is used to achieve complex bespoke three-dimensional surfaces at a large scale, with a minimum residual waste during continuous digital manufacturing2–4. This permits to depart from the cut-pattern-based strategy commonly used for woven non-expandable membranes while allowing for the integration of multiple material properties in a single production process.

Dancing Tent: Computational Structural Modeling and Choreographic Approach for the Kinetic Design of a Tent Structure

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:46:04 +0200

BATS - A software for the parametric design of membrane structures

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:45:44 +0200

Mean curvature flow for generating triangular meshes with piecewise constant mean curvatures

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:45:12 +0200

Re-manufacturing textiles within circular economy: trials of closing the loops of Textile-based Tertiary Architecture

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:39:49 +0200

Assessing the life cycle of temporary membrane structures based on two case studies

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:39:31 +0200

Optimization of the design phase and the End of Life scenarios of Textile Façade Retrofit interventions

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:39:17 +0200

Life Cycle Assessment of Building ETFE Cushion for Circular Economy

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:39:00 +0200

Floating membrane roofs for large zootechnic and industrial storage tanks

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:27:42 +0200

Large Span Membrane Architecture: How to Accomplish Carbon Neutral with Innovative Photovoltaic and Adaptive Control Strategy

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:27:11 +0200

Thermodynamic and structural Behaviour of textile Covers for Biogas Storage Systems

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:26:39 +0200

Self-cooling textiles – energy-free method using radiative cooling technology

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:26:17 +0200

Membrane attached Photovoltaics

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:25:55 +0200

Similar design of retractable roof in two different sizes – identical motion planning?

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:19:40 +0200

Move it and fold it!

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:18:43 +0200

Operational Planning and Design Issues for Retractable Membrane Roofs

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 11:17:56 +0200

On the long-term behavior of ETFE foils - evaluation of monoaxial creep tests after one hundred thousand hours

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 10:46:31 +0200

The Determination of the Mechanical Performance of Membrane Structures in Architectural Applications

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 10:46:17 +0200

Comparative Assessment Of Life Cycle Aspects Of Lightweight And Conventional Structures And Their Integration Into An Educational Approach

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 10:46:00 +0200

. The article provides information on how teaching sustainability can be applied in a practical context. A comparison of the life cycle of two roof variants and their evaluation shows how the teaching concept can be implemented.

Tensile Behaviour of ETFE Foils with Various Types of Area Weld Seams

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 10:45:42 +0200

ETFE foils are already an established building material in membrane construction. Many prestigious buildings have already been realised with the transparent and printable foils. The manufacturing and installation of the mostly double-curved ETFE foil structures are made possible by the weldability of the fluoropolymer. The manufactured weld seams can be divided into area and edge weld seams. Both types of ETFE weld seams provide a lower uniaxial tensile strength in comparison to the base material. Weld seams in ETFE structures are the decisive points for the limit state design, see also FprCEN/TS 19102, which for the first time provides a standardised design concept for membrane structures based on the Eurocode design philosophy. With the release of prCEN/TS 19102, a minimum tensile strength and a partial safety factor for area weld seams are given relying on the partial safety concept of the Eurocodes according to EN 1990. Nevertheless, the given values are not based on a comprehensive experimental test evaluation so far. In the frame of this contribution, for the first time, results of investigations into the tensile strength of different configurations of area weld seams are presented. These configurations include different manufacturers, foil products, foil thicknesses, test temperatures, types of area weld seams and welding processes. Based on these results, a general minimum requirement for the tensile strength of area weld seams could be determined for future standardization processes beside that a new reliability analysis according to EN 1990 for the determination of the partial safety factor for area weld seams has been carried out. These new results will be used to improve the design concept of the future Eurocode for membrane structures which will be developed on the basis of prCEN/TS 19102. In this contribution first results of this investigations are presented

Thermomechanical characterisation and linear viscoelastic modelling of ETFE membranes

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 09:38:19 +0200

Experimental Study on Precise Forming of Inflated Membrane Structure Using Airship Membrane Material

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 09:38:03 +0200

Buoycrete, a light-weight concrete in combination with a membrane mold

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 09:37:45 +0200

In this study, the authors present Buoycrete, a new material and work method invented by the company Boskalis. “Buoycrete” is a new cement mixture and work method. This mixture and the work method related to this material are developed by Boskalis and are patented in 2017. The material is a lightweight concrete mixture that is ‘neutrally buoyant’ and non-dissolvable. The concrete is intended to be used under water. The neutral buoyancy makes that the concrete does not sink or float. In other words, within the cement mixture under water, right after application, there is no resultant vertical force apparent because of the neutral buoyancy. The cement slurry will be kept in place only by the internal cohesion of the Buoycrete slurry itself. This allows for fast and flexible adjusting of the concrete shape under water before the concrete cures. The unique cement-based grout opens up a wide array of possible application areas and markets, especially since application equipment, mixing equipment and curing characteristics are analogue to normal cement mixtures. Currently, there are no comparable light-weight cement mixtures available on the market. This paper will start with an overview of concrete structures in combination with fabrics and will present the structural behavior, construction methods and applications of Buoycrete. It demonstrates that Buoycrete combined with fabric formwork creates new possibilities for the restauration of key walls but can also be used for the realization of façade elements, shell structures and other free forms.

An Analytical Method for Precise Forming of Membrane Structure Considering the Spindle Direction of Membrane Material

Jesús Sánchez Pinedo — Thu, 19 Oct 2023 09:37:29 +0200

Shaping Steel Grid Shells by Applying a Visual Programming Language

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:15:50 +0200

A new numerical model for deployment process of inflatable aerodynamic decelerator based on the reverse modelling technique and control volume method

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:15:32 +0200

Tracing non-linearities in the load bearing behavior of structural membranes: an investigation of typical shapes and load cases

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:15:16 +0200

. One of the prevalent challenges in the design, numerical analysis and verification of structural membranes lies in the non-linearity of their load-response curves. Structural analysis has to be performed with a geometrically non-linear approach, due to the interaction of form and forces and thus a linear extrapolation or combination of analyis results is not possible. The appropriate modeling of the environmental impacts (such as wind and snow) also has a significant influence on the analysis results. Furthermore, non-linear material behavior can be of interest. The resulting load-response curves (e.g. stresses, deformations) are typically non-linear and their interpretation towards the underlying safety requirements is not straight forward. In addition, the prestress also has a major influence on membranes' structural behavior. However, the current European regulations for the proof of the limit states (ULS and SLS) of any building requires a simplified categorization of the structural behavior. This research investigates the load-bearing behavior of typical re-occurring membrane shapes in the context of current verification requirements. Typical load cases are applied and the structural behavior is shown under consideration of the mentioned non-linearities.

Computational sensitivity analysis of hybrid lightweight structures

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:15:00 +0200

Shape-adaptive Climate Loading of Tensile Surface Structures

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:14:02 +0200

This paper deals with climate loading of tensile surface structures. The approaches for the snow load calculation were summarized and a new usage for tensile surface structures based on established procedures has been proposed. The snow load distribution and accumulation was presented in the form of an algorithm implemented in a finite element software. The results of the algorithm for snow load accumulation were verified on simple examples with vertical, inclined and curved surfaces.

Correlation between uniaxial and biaxial creep behaviour of ETFE foils

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:13:12 +0200

Design and Construction of an Asymptotic Geodesic Timber Gridshell

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:12:56 +0200

Does the stress-strain behaviour of PTFE-coated glass fibre fabrics depend on the load history?

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:12:40 +0200

It is known that PTFE-coated glass fibre fabrics show a mechanical saturation behaviour under repetitive monotonous loads [1]. That means that the stress-strain behaviour changes from load cycle to load cycle. This behaviour is convergent so that stiffness values strive towards asymptote values. However, when using these fabrics in membrane structures they are subjected to various natural load histories which lead to biaxial stresses with different stress ratios in different orders. The question arises whether loads of different orders lead to a different material response. If so, stiffness parameters would not be global but would have to be given dependent on the order of loads.

Enhanced design and modelling productivity with Parametric design

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:12:27 +0200

This paper focuses on the use of modern parametric design and modelling tools to accelerate the challenging and difficult large design projects. The methodology is also suitable in dealing with renovation and/or modification in the existing structures. Two project examples are presented here namely, construction of membrane façade to existing structure of football stadium Metz, France and renovation of the roof of main train station Dresden, Germany. The structures have deformations with the passage of time and the renovation is more complicated as compared to the theoretical form. Parametrization makes the tasks feasible with enhanced productivity, efficiency and accuracy

The calculation of equidistant cable-nets

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 18:12:14 +0200

Experimental investigations on Structural Behaviour of Two-layer-stacked ETFE film Square Planar Structure Under Normal Pressure Loading

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 17:59:54 +0200

Thermal Performance of Membrane Structures Integrated Phase Change Materials

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 17:59:34 +0200

The membrane structures, one of the typical large-span spatial structures, have been widely-used for sports stadiums and transportation hubs. However, the thermal performance of architectural membrane materials is not as good as those of the traditional building materials. The phase change material can absorb and release latent heat by changing its states within a very small range of temperature change, and thus reducing indoor temperature fluctuation and improving thermal comfort. In this paper, we proposed several membrane structural types to improve the thermal performance, including changing the single-layer membrane structure into two-layer, and setting air or phase change materials as the insulation layer in the middle. Temperature field simulations are performed based on COMSOL software to investigate the temperature variation and thermal performance of the membrane structures. The daily maximum temperature on the inner surface decreased by 2.1°C and 8.1°C respectively with air and PCM layer. We also discovered that the thermal insulation performance will be better when the latent heat value is higher and the PCM layer is placed nearer to the outdoor side. The temperature-stress coupling field showed the loss of pre-stress can be reduced by about 50% by adding PCM layer. The research results are believed to be significant for energy-saving and CO2 emission reduction in large public buildings.

Designing A Large Span Structures Under Seismic Loading – A Case Study

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:36:27 +0200

Structural membranes have become a frequently preferred system type in long span structures such as amphitheatres, stadiums, performance centres, sport halls, with their ability to cover long distances by lighter solutions. The membrane material, which is the main component of the lightweight structures including membranes and has sufficient strength together with stretching, has very low weight of around 1 kg per sqm compared with the conventional load bearing materials. This is very important feature, both aesthetically and economically. Its light weight does not only provide an economical solution, but also allows to have better structural performance under seismic loads. Besides its lightness, another advantage of membrane-covered structures such as the amphitheatre is acoustic performance, which is an important one for the structure to meet serviceability requirements

Creating a meeting space for people – a new roof for the SMS Campus in Mönchengladbach, Germany

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:36:13 +0200

Case Study: Santiago Bernabéu Stadium

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:36:02 +0200

Unusual design drivers for membrane structures and details

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:35:47 +0200

Design and installation of a large pneumatic dome in Brazil

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:35:33 +0200

Medijana-Niš Archeological Site Protection Membrane Structure

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:35:20 +0200

The "Medijana" project was designed to protect one of the most important archaeological excavation sites from the ancient Roman period in Serbia, and presented a significant challenge due to its location as a candidate for UNESCO heritage protection. In 2023, the project has been completed, with total covered surface of 12,000 m2, a main clear span of 80m and a length of 148m, one of the largest membrane structures in this region of Europe. The site-specific limitations and conditions required careful planning and logistics. As such, this project serves as a unique case study that illustrates the interplay between design, limitations, and consequently the need for innovative detailing and installation techniques. Through monitoring and observation over a period of 9 years, a wealth of information including wooden structure – membrane interaction, microclimatic conditions, and maintenance has been collected, which will be valuable for future developments, the field of membrane structures in cultural heritage applications and beyond.

PumpItUp, gite mobile for the European cultural capital Esch-sur-Alzette

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:35:03 +0200

This paper presents the project PumpItUp, from the design to the fabrication and installation. It is a pneumatic shell on a trailer with two foldable wings. The shelter is set up and dismantled several times, at different locations. The pneumatic envelope forms a spherical shape from two layers of membrane, coupled at many nodes with synthetic fibre ropes

Detailing of Tensile Architecture and the Adoration of the Joint

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:34:21 +0200

A folding cover on the Suzanne Lenglen court, Roland-Garros, Paris

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:33:41 +0200

Experiences after 10 Years of Operation and Maintenance of the Retractable Roof at BC Place

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:33:27 +0200

Customised Fibre Panels: A New Tool for Architectural Applications

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:33:16 +0200

Drive system innovation – winch development for moveable membrane structure

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:33:05 +0200

Technical evolution of a convertible pool roof on three expedition cruise ships for the shipping company Hapag Lloyd

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:32:52 +0200

Urban retractable roofs

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 16:32:39 +0200

Between Structure and Architecture

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 13:29:59 +0200

Thanks to their flexibility, lightness and robustness, textile works are often used to cover large spaces. Structural efficiency of tensile structures can usually be related to a double curvature geometry. However, the project of the new Brugge Stadium offers a new challenge: the realisation of a flat façade with porous zebra strips of different porosity. The strips are 45° inclined with alternating porosities to create visual zebra effect during day and night as it permits light to pass from both the inside and the outside. With this choice come several design issues. The porous meshes should be prestressed, with its uncommon angle of 45° oriented mesh and the structural span is too important for existing meshes. Consequently, a close collaboration with textile companies was necessary to develop a mesh tailored on the need of the project and on the architectural design intents. The design process followed several steps, among the most significant : 1) understanding of the structural challenges to develop a new product adapted to the project 2) definition of the design criteria related to the dynamic behaviour of flat facades, 3) comparison of a stiff and a soft supporting structure (straight cables) 3) interface of the façade to the main concrete structure of the stadium. In the final design, the membrane is supported by a steel structure diagonally arranged to follow the pattern of the membrane arranged in 35-metre long strips. The steel beams inclined by 45° are preferred to the cable solution: the complications due to pretension are limited, the connection details can be designed to merge visually with the strips, the forces applied to the concrete structure are limited. A special mesh was developed to guaranty the 45% porosity required by the architect and the structural requirement for a 6m span diagonal strip : this design process hints at future design possibilities for textiles structures that could match the architectural intents with some R&D and a direct collaboration with the textile industries.

Practical implementation of a thermo visco elastic material model for the design and analysis of ETFE structures

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 13:29:38 +0200

Beyond bending: tension. Membrane structures II

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 13:29:22 +0200

Jürgen Hennicke [1] challenged the designers of structural membranes stating that "Structural membranes, if not designed as such, require an imposing steel structure". Responding to this challenge, a comparative study has been launched to assess the impact on the design efficiency of considering or not the structural principles of membranes, that are: only tension, funicularity, curvature and pre-stress. In a previous paper (J.Llorens, 2023 [2]) the general approach of the research and the first results have been presented. This paper shows more cases to complete the most usual repertoire.

HydroSKIN: Climate-resilient Membrane Façade Prototyping

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 13:25:09 +0200

Main Canopy of Islamic Complex, Putrajaya, Malaysia – A Testimony to Excellent Performance of PTFE Membrane under Tropical Climate

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 13:20:59 +0200

This paper describes a landmark membrane structure where the surface appearance has been able to be maintained after years in service. The membrane structure is the main canopy structure located at the courtyard of Islamic Complex, Putrajaya, Malaysia. It is made using PTFE membrane which is known for its excellent durability. The construction process of the main canopy together with the mini canopy which consists of a group of four funnel-shape membrane structure made using PVDF membrane will be presented in this paper. The paper will also touch on the performance of PTFE membrane in humid tropical weather condition like Malaysia.

Development of Air-inflated Lifting Equipment

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 13:20:41 +0200

The research aimed to develop air-inflated equipment for lifting catamaran components during construction. The main structural parts of a newly developed catamaran are two hulls and three closed boxes. The three boxes connect the hulls and hold the deck. Different construction procedures were analysed to connect the main structural parts. One possibility is to float the hulls and the three boxes one by one on the water, lift the boxes to the required position with inflated tubes or pillows and connect the parts. Air-inflated tubes with various geometry and internal pressure have been analysed with the help of the Dynamic Relaxation Method. The deformed shape of the floating tubes, the membrane stresses, and the lifting forces were determined.

Structural Membrane of Levante Stadium Cable Roof

Jesús Sánchez Pinedo — Wed, 18 Oct 2023 13:20:22 +0200

A Mathematical Model to Estimate the COVID-19 Pandemic in Red Lights of México

JORGE LOPEZ LOPEZ — Wed, 18 Oct 2023 05:59:10 +0200

The goal of this work is a dynamic and numerical study of a compartmental mathematical model in order to know the evolution of state variables of the pandemic caused by COVID-19 on red spotlights in México. The model include 7 compartments and the results were compared with the classic SIR model, resulting that our predictions adjusted better the official data. A parameter sensitivity analysis is included.

Dangers of Catcalling: Exploring the Lived Experiences of Women Catcalled in Quezon City

Kyle Patrick De Guzman — Tue, 17 Oct 2023 18:56:04 +0200

Despite being a women's problem for a long time, catcalling has recently attracted lawmakers' attention. In 2019, the Philippine government enacted Republic Act 11313, or the Safe Spaces Act, which prohibits and punishes gender-based sexual harassment. However, despite the existence of the law, catcalling continues to be rampant. This study aims to explore the experiences of women in Quezon City who have been subjected to catcalling and to provide answers regarding the effects of catcalling on the victims, the locations where catcalling is most prevalent, the most common perpetrators, and the victim's views on the Safe Spaces Act. This research uses a qualitative descriptive approach. Purposive sampling was used to select respondents, and respondents were interviewed using an interview guide to gather information. The findings indicate that women are most vulnerable to catcalling in public spaces, and the perpetrators are strangers or bystanders. Victims went through mental, emotional, and behavioral changes after the incident. Moreover, not all victims think that the law effectively addresses the problem because catcalling is still prevalent, and public awareness campaigns are lacking.

Investigation on the Effects of Using Lithium on Biochemical Factors of Urinary Beta-2 Microglobulin, Creatinine and Urea Serum in Chronic Bipolar Patients

Reyhaneh Rahimi — Fri, 13 Oct 2023 20:55:03 +0200

In this research, the effects of using lithium on biochemical factors of urinary beta-2 microglobulin, creatinine and urea serum in chronic bipolar patients hospitalized in Razi psychiatric center are investigated. For this purpose, random sampling method was used and among hospitalized patients in Tehran's Razi psychiatric center. Then 87 patients were selected and urinary beta-2 microglobulin tests by ELISA method, urea and blood serum by enzymatic method measured in 42 bipolar patients (including 18 females - 24 males) that using lithium and 45 bipolar patients (including 21 females - 24 males) that using drugs other than lithium. According to studies, lithium-treated bipolar patients have a substantially greater urine beta-2 microglobulin concentration than individuals who are not lithium-treated (Pvale> 0.028). The results demonstrated that the longer time of using lithium will cause higher amount of urinary beta-2 microglobulin secretion (Pval> 0.027). Also, the results showed that the value of creatinine and urea serum were not significantly different between two groups. Finally, it seems that urinary beta- 2 microglobulin is a better indicator than urea and creatinine serum to evaluate the side effects of primary kidney damages caused by lithium, and its main role in diagnosis of the disease requires further researches in this field.

Analysis of the possibilities of improving the quality of forecasting prices for certain types of raw materials using the simplest methods of combining individual forecasts

Elisaveta Grebennikova — Fri, 13 Oct 2023 13:15:03 +0200

Currently, combining forecasts is considered as the easiest way to improve the quality of forecasting compared to individual models.
The purpose of this work is to test the possibilities of the simplest methods of combining, such as a simple average and estimates based on the average squared error of forecasts of previous periods, to improve the qualitative characteristics of short-term forecasts of five indicators of resource prices. The work is based on the forecast base of the Bulletin of Short-term Forecasts of the IEP, which provides an array of primary (combined) forecasts and allows you to build their combinations in real time.
The results obtained allow us to conclude that even the simplest methods of combining can be considered as a way to improve the accuracy of forecasts. In addition, in the case of fluctuations in resource prices, it is even possible to single out a group of methods (namely, combining with weights inversely proportional to the squared errors of individual forecasts) that provide the maximum gain in quality for most periods.

Far East and Far North: how to prevent an outflow of young people

Elisaveta Grebennikova — Thu, 12 Oct 2023 15:45:03 +0200

The outflow of the population of young working age from the regions of the Far East and the Far North is a serious constraint on the economic and social development of these regions. Unfavorable climatic working and living conditions, underdeveloped economic and social infrastructure, distance from development centers, relatively low wages and lack of career and personal prospects - these factors encourage a significant part of young people to leave the region of the Far East and Far North. The objectives of the study are to answer the following questions: • What is the scale of departure of young people from the Far Eastern Federal District and the Far North? • What are the reasons for their departure? • How reliable are disposal volume statistics? • Is it possible for at least some of the young people to return to the regions of origin and under what conditions? The study was conducted on the basis of Rosstat statistics on the volume and structure of internal migration in Russia for 2011-2020, the results of a sample survey of the labor force in 2029-2022, as well as Rosstat reports “Socio-economic situation in Russia” in 2018-2022. The study shows that published statistics underestimate the real scale of the outflow of young workers from the regions of the Far East and Far North due to the so-called “auto-return” process. The North and Far East are losing young people during migration exchanges with large and major cities in the European part of the country. Large cities of the North and Far East compensate for the loss due to the influx from the periphery of these same regions. Retaining young people in the labor markets of the regions where they were born is only possible if there is an influx of investment into the regional economy and social sphere, and this process should not have the character of a short-term campaign, but be a long-term guarantee for several generations of workers.

A brief overview of theoretical and empirical approaches to solving transport problems and problems on the development of transport networks

Elisaveta Grebennikova — Thu, 12 Oct 2023 14:19:03 +0200

The paper presents a brief review of some aspects of existing theoretical and empirical research on transportation and transport networks development problems. Despite the fact that in general this direction is well developed in the research literature, in practice some issues require more detailed consideration, in particular, approaches to modeling the transportation of various goods over a multilayer network, representation of transportation and other costs, setting the criteria of optimality of network development. In addition, this paper considers cost functions and variables determining them, the influence of borders on the transport system, optimal routing and its paradoxes.

Review of approaches to ecological and economic modeling and assessment of the effects of the development of transport and transport infrastructure on environmental indicators of territories

Elisaveta Grebennikova — Thu, 12 Oct 2023 14:04:06 +0200

The main theoretical and empirical approaches to modeling the interaction between socioeconomic indicators and anthropogenic load on the environment are considered. The most common approaches to measuring the environmental load on territories and population are environmental models IPAT, STIRPAT, modeling the impact of socio-economic characteristics on the environment. Extension of the models also allows taking into account the characteristics of the transportation industry and modeling their impact on the volume of emissions from road transport. According to economic studies, road infrastructure development has a dual impact on the environment. While better infrastructure can help reduce emissions from road transport, it also stimulates economic activity and travel demand, which increases emissions. The emission reduction effect of road network development is more likely to be observed in regions where infrastructure saturation exceeds the level needed to meet current, including latent, travel demand. Thus, the development of road transport infrastructure at a pace that outpaces the economic development of the region can contribute to reducing the environmental burden. In addition, approaches to analyzing causal relationships between variables and assessing the overall, direct and indirect effects of factors on ecology are discussed: structural modeling and path analysis based on the structure of a simple directed graph.

Improving the accuracy of bubble date estimators under time-varying volatility

Elisaveta Grebennikova — Thu, 12 Oct 2023 13:51:03 +0200

In this study, we consider a four-regime bubble model under the assumption of timevarying volatility and propose an algorithm of estimating the break dates with volatility correction. First, we estimate the emerging date of the explosive bubble, its collapsing date, and its recovering date to the normal market under the assumption of homoskedasticity. Second, we collect the residuals and then employ the weighted-least-squares-based estimation of the bubble dates. Using Monte Carlo simulations, we demonstrate that the accuracy of the break date estimators improves significantly via this two-step procedure in some cases compared to those based on the ordinary least squares method.

New Challenges for the Russian Energy Industry

Elisaveta Grebennikova — Wed, 11 Oct 2023 15:30:05 +0200

Currently many sectors of the Russian economy, including the fuel and energy sector, are undergoing structural changes. This is due both to the energy transformation (a significant change in the structure of the energy balance) and the recent events of 2022. The article analyzes how these changes will affect the Russian energy sector. Firstly, the risks of reducing natural gas exports to the EU countries are assessed. Gas supplies to the EU are a significant part of Russia's export earnings, and the supplies themselves are difficult to redirect to other directions. Secondly, it is analyzed how recent changes will affect the development of the energy sector using the example of two scenarios for the development of the energy industry before and after 2022. Finally, it is assessed how the changes that have taken place will affect the effectiveness of an active climate policy in Russia. The possibility of a reduction in domestic demand for gas in the EU or an increase in production is unlikely. However, an increase in LNG (liquefied natural gas) imports is possible, which may allow the EU to abandon natural gas imports from Russia in the coming years. EU nominal regasification capacity allows for a potential increase in EU LNG imports by 110 billion cubic meters per year. This can be done both by redirecting supplies from other countries to the EU, and by increasing production and liquefaction of LNG. As a result of an increased sanctions pressure, with a high degree of probability, without an active climate policy, the level of greenhouse gas emissions will increase significantly. In addition to climate effects and associated negative environmental impact, this also negatively affects the prospects for economic development. Thus, greater consumption of fossil fuels makes the economy more dependent on their prices and reduces the potential for an increase in the volume of export. An analysis of decarbonization scenarios has shown that because of the recent events, an active climate policy will cost more, with more modest results.

MICROECONOMIC ANALYSIS OF INVESTMENT STRATEGIES OF FOREIGN COMPANIES IN RUSSIA IN THE CONTEXT OF THEIR FOREIGN TRADE ACTIVITIES A. Knobel, Yu Zaytsev, D. Kuznetsov

Elisaveta Grebennikova — Wed, 11 Oct 2023 14:51:03 +0200

This working paper is devoted to identifying patterns of spatial and sectoral distribution of foreign direct investment enterprises in the Russian Federation and to developing recommendations for optimizing the strategy of attracting foreign direct investment to the Russian Federation.

In the framework of the study, the following methods were applied: the method of macroeconomic modeling, evaluation of econometric models, as well as logical, systemic, comparative, economic and statistical analysis. Statistical data at the enterprise level were used from the «RUSLANA» and «SPARK-INTERFAX» databases.

The results of the study allows to point out some characteristic features of the spatial distribution of foreign enterprises, which must be taken into account when forming a picture of preferences of foreign investors and the policy of attracting foreign investors to Russian regions.

THE IMPACT OF THE DYNAMICS OF THE RUBLE EXCHANGE RATE ON THE INFLOW OF FOREIGN INVESTMENTS INTO THE RUSSIAN ECONOMY AND THE CONDITIONS OF SANCTIONS

Elisaveta Grebennikova — Wed, 11 Oct 2023 14:37:04 +0200

The statistics on foreign direct investment (FDI) for 2017 published in early April by the Central Bank of Russia shows a change in the dynamics of an increase in FDI inflows to the Russian Federation that was outlined in 2016 and in the first three quarters of 2017. The slowdown in capital inflows in 4Q 2017 reflected the deteriorating sentiment of foreign investors associated with negative expectations of new US sanctions, as well as a drop in demand for Russian government bonds.

Positive investor sentiment was reflected by the positive dynamics of FDI flows in the first three quarters of 2017, when the level of incoming FDI amounted to USD 24.8 billion, which is more than 2 times compared to the same period in 2016. The increase in inflows over this period is due to transactions such as the sale of a 10% stake in the Russian petrochemical holding Sibur to the Chinese Silk Road Fund, the launch of the construction of a Mercedes-Benz automobile plant by the German company Daimler in the Esipovo industrial park, which became the first largest project after the introduction of anti-Russian sanctions by the Western company in Russia.

Existing assessments of the impact of sanctions on key macroeconomic indicators provide a rough understanding of their significance for foreign investors. Under the new conditions, foreign investors developed their own approaches to respond to the sanctions regime, depending on their sectoral specialization and the degree of orientation towards the Russian and/or foreign markets. Nevertheless, according to the results of 2017, the volume of foreign direct investment (FDI) attracted to Russia from the EU countries exceeded USD 14 billion (which is more than 6 times the level of 2016). Consequently, a high potential for investment cooperation remains between Russia and the EU countries, despite the sanctions regime.

Relevance of the study: portfolio and foreign direct investment are an important source of capital that complements domestic private investment and is often associated with creating new jobs, stimulating technological exchange and encouraging overall economic growth in host countries. Important factors in FDI inflows are the level of the exchange rate and its volatility. The need for an empirical analysis of the impact of the exchange rate on FDI inflows to Russia is caused by the currency crisis of 2014-2015, when the Russian ruble devalued due to the fall in world oil prices, as well as a number of foreign policy events.

The purpose of this study is to assess the impact of the level of the exchange rate and its trend on the inflow of direct and portfolio foreign investment in the Russian Federation. In accordance with the goal, the following tasks will be solved:

– Review of the theoretical and empirical literature on the role of the exchange rate in the inflow of foreign investment;
– Analysis of foreign direct investment flows in Russia and in the world;
– Building models that take into account the impact of the exchange rate of the national currency of Russia on the inflow of foreign direct investment in the sectors of the Russian economy;
– Evaluation of econometric models to study the influence of the exchange rate on the inflow of foreign direct investment to the countries of the world in order to test the hypotheses put forward in the work;
– Interpretation of the results and development of recommendations for the

Russian foreign economic policy, taking into account the results of the study.
The initial data of the work were statistical databases, both international and Russian, in particular, open statistical data provided by the Central Bank of the Russian Federation, the Federal State Statistics Service, the Eurasian Economic Commission, regulatory and program documents regulating the activities of the regions of the Russian Federation with a special (special legal) regime for the implementation of entrepreneurial and other activities, as well as cases of the largest and most successful investment projects implemented on the territory of individual constituent entities of the Russian Federation.

Practices of preparing students of vocational educational organizations for the process of labor adaptation

Elisaveta Grebennikova — Wed, 11 Oct 2023 14:11:03 +0200

The relevance of the research is determined by the increasing importance of professional qualities of an individual, ensuring quick and successful labor adaptation, in connection with the situation of production restructuring, including those due to a change in technological priorities in several industries and the import substitution strategy, as well as instability of regional labor markets. The object of observation is working practices both individual events and features of the educational process as a whole – aimed at ensuring successful labor adaptation of graduates of vocational educational organizations. The purpose of the research is to identify the practices of vocational educational organizations aimed at ensuring successful labor adaptation of graduates and assessing its effectiveness on the part of the management of these organizations, as well as the attitude of managers to the task of developing key competencies of graduates as a resource for labor adaptation. The research tool is an unstructured interview. Main results. A contradiction was identified between the need for regular labor adaptation in connection with both a change of workplace and fundamental changes in the conditions and requirements for the occupied workplace and the position of the management of vocational educational organizations, whose representatives see their task in employing a graduate and facilitating his/her retention in the workplace, and not in the formation of a personal resource for his/her successful adaptation. Employees of vocational education and training (VET) organizations share the idea that the basic components of the personal resource for labor adaptation are universal competencies in the field of communication, working with information and problem solving, but these ideas in most cases are not implemented in educational activities. At the same time, it was possible to identify and describe the practices of individual VETs that ensure the formation of a personal resource for labor adaptation, which can be recommended for dissemination. Scientific novelty. Based on a survey of the management of VET organizations, current practices in preparing young people studying in VET programs for the process of labor adaptation are described and analyzed; in the aggregate of which practices are identified which allow the formation of a set of qualities that are a personal resource for labor adaptation. Recommendations. The results obtained make it possible to adjust the target orientation and update the processes of preparing graduates for the process of labor adaptation using the practices of educational organizations that are adequate to the purpose. The results of the study can be used by federal and regional educational authorities to set tasks for professional educational organizations and vocational education and training organizations in terms of selecting means to solve the problem of forming a personal resource for labor adaptation.

WHERE BRICS IS HEADING: DEMOGRAPHIC AND VALUE DEVELOPMENT SCENARIOS

Elisaveta Grebennikova — Wed, 11 Oct 2023 14:04:05 +0200

Relevance. The relevance of “non-Western” associations of states, such as BRICS, is rapidly increasing as the global world order is in transit to multipolarity, going through geopolitical aggravation. The subject of the study is the demographic future of the BRICS countries and value shifts in these countries. The purpose of the study is to determine the impact of the demographic future of the BRICS countries on the prevalence of certain value attitudes among the population of these countries. The objectives of the study are to construct scenario forecasts for the demographic future of the BRICS countries and forecast the most significant consequences of each scenario in terms of shifts in value attitudes. Novelty – for the first time, the consequences of certain demographic development scenarios of the BRICS countries for the value landscape of these countries are considered. Research method: to construct scenario demographic forecasts, a cohort-component model (“age shifts”) of the “female-based” type was used. Data sources – to determine the value portrait of the country, the WVS data of the seventh wave was used; a country’s place on the map of values is determined by two axes – the axis of survival/selfexpression values and the axis of traditional-religious/secular-rational values. Results – it is shown that negative demographic scenario can lead to a noticeable weakening of BRICS both economically (due to a reduction in labor resources) and in value-cultural terms on the world stage. Conclusions – the implementation of the BRICS+ project will contribute to the significant impact of the union on the value-cultural map of the world. Recommendations. If the governments of China and Brazil do not soon take care of the problems of fertility rates and do not introduce the most active measures to support them, then the countries will find themselves in a “fertility trap” with a strong decline in population that cannot be compensated by migration. India should also begin to develop and take measures to support fertility rates, because due to active modernization, they will begin to naturally decline (which is what has been happening over the last decade, especially in the developed south of the country). Russia needs to simultaneously both pursue a proactive fertility-supporting policy, eliminate excess mortality from unhealthy lifestyles, and increase health care spending.

CONVERGENCE OF VALUES IN THE GLOBAL CONTEXT

Elisaveta Grebennikova — Wed, 11 Oct 2023 13:52:02 +0200

Relevance. The issue of convergence/divergence of value systems remains debatable, and the expectation that, as they develop, the countries of the semi-periphery and periphery of the World System will move in one universal direction and become increasingly closer to Western countries does not seem unconditionally justified. The subject of the study is the dynamics of value attitudes of the population of Latin American countries. The purpose of the study is to establish the convergence/distance between the population of Latin American countries and the countries of the Old World in terms of their value systems. The objectives of the study are to predict the dynamics of value attitudes of the population of Latin American countries relative to the countries of the Old World. Scientific novelty – for the first time, the dynamics of value systems of the population of Latin American countries relative to the countries of the Old World is considered. Research method – To analyze the influence of various factors on the two value axes identified by Inglehart, a general additive model with mixed effects on the country (random intercept) was used. Data source – the World Values Survey. Results: in terms of traditional/secular values, the countries of South America had almost no overlap with the countries of Western Europe at the beginning of the 21st century, but the gap is narrowing from year to year. In terms of survival/self-expression values, there is a certain kind of conservation of persistent differences between the developing countries of the New World and the developed countries of the Old World, when both regions almost do not overlap. Conclusions – over time, largely thanks to the rapid breakthrough of developing countries, the world will converge along the axis of traditionalreligious/secular-rational values. Recommendations. The New World is increasingly catching up with the Old World in terms of secular-rational values, which should be considered when forecasting the sociocultural dynamics of this region. However, this does not mean that Latin America will become completely identical to Western Europe in terms of religiosity/secularism.