Abstract

An architectural design process is investigated to achieve form flexibility in industrialized building systems (IBS), as IBS constructions do not have sufficient flexibility to develop varied architectural forms. The ethnography method has been used to examine the issues related to “form” flexibility in the design life cycle of IBS constructions by observing the constructions of live experimental models. The major tasks and respective design aspects that facilitate form flexibilities in architectural design have been identified. Furthermore, an integrated life cycle model has been developed to effectively address the interfaces between the design tasks and eventually fulfill the needs of IBS in the design life cycle.

Abstract

The environment in villages in Southwest China has been experiencing constant changes, indicating related change-inducing factors as well as their constitution and hierarchy. Starting from the classification of built environment according to Rapoports view, the “environment” consists of fixed, semi-fixed and unfixed elements (A. Fixed-feature elements: infrastructure, buildings, walls, floors, etc. B. Semi-fixed-feature elements: “furnishings” of the environment, interior or exterior, trees and gardens, fences, signs, billboards, lights, etc. C.Unfixed-feature elements: typically people and their activities, behaviors, etc.). Five representative historic villages in Southwest China (Zhenshan Village in Guizhou, Zhanglang Village in Yunnan, Moluo Village in Sichuan, Huaili Village in Guangxi, and Gongzhong Village in Tibet) were investigated to demonstrate the changes in terms of landscape in the last decade. This article provides an analysis of the dialectical relationship between reservation practices and evolving landscapes from a diachronic perspective. This analysis reveals defects of heritage conservation projects for historic villages in Southwest China. The results indicate the following: (1) there exists an important relationship between unfixed-feature elements of landscape and cultural heritages in historic villages, (2) semi-fixed-feature elements, although being neglected in most preservation practices, show strong sensitivity to mass tourism, (3) fixed-feature elements are highly vulnerable to civil engineering techniques, and (4) the most active change-inducing factors for evolving landscapes in historic villages include value orientations of villagers, relative locations of villages, ethnic groups, customs, and economic development. In conclusion, approaches to promoting sustainable development of historic village in Southwest China are explored.

Abstract

Prevailing city design in many countries has created sedentary societies that depend on automobile use. Consequently, architects, urban designers, and land planners have developed new urban design theories, which have been incorporated into the Leadership in Energy and Environmental Design for Neighborhood Development (LEED-ND) certification system. The LEED-ND includes design elements that improve human well-being by facilitating walking and biking, a concept known as walkability. Despite these positive developments, relevant research findings from other fields of study have not been fully integrated into the LEED-ND. According to Zuniga-Teran (2015), relevant walkability research findings from multiple disciplines were organized into a walkability framework (WF) that organizes design elements related to physical activity into nine categories, namely, connectivity, land use, density, traffic safety, surveillance, parking, experience, greenspace, and community. In this study, we analyze walkability in the LEED-ND through the lens of the nine WF categories. Through quantitative and qualitative analyses, we identify gaps and strengths in the LEED-ND and propose potential enhancements to this certification system that reflects what is known about enhancing walkability more comprehensively through neighborhood design analysis. This work seeks to facilitate the translation of research into practice, which can ultimately lead to more active and healthier societies.

Abstract

Research from multiple domains has provided insights into how neighborhood design can be improved to have a more favorable effect on physical activity, a concept known as walkability. The relevant research findings/hypotheses have been integrated into a Walkability Framework, which organizes the design elements into nine walkability categories. The purpose of this study was to test whether this conceptual framework can be used as a model to measure the interactions between the built environment and physical activity. We explored correlations between the walkability categories and physical activity reported through a survey of residents of Tucson, Arizona (n =486). The results include significant correlations between the walkability categories and physical activity as well as between the walkability categories and the two motivations for walking (recreation and transportation). To our knowledge, this is the first study that reports links between walkability and walking for recreation. Additionally, the use of the Walkability Framework allowed us to identify the walkability categories most strongly correlated with the two motivations for walking. The results of this study support the use of the Walkability Framework as a model to measure the built environment in relation to its ability to promote physical activity.

Abstract

Well-functioning cities reduce the economic distance between people and economic opportunities. Cities thrive because they enable matchmaking -- among people, among firms, and between people and job opportunities. This paper examines employment accessibility in Nairobi, Kenya and evaluates whether modification of land use patterns can contribute to increases in aggregate accessibility. The assessment is based on simulation of counterfactual scenarios of the location of jobs and households throughout the city without new investments in housing or transport infrastructure. The analysis finds that modifications to the spatial layout of Nairobi that encourage land use clustering can increase the share of overall opportunities that can be accessed within a given time-frame. When commuters travel by foot or using the minibus network, the share of accessible economic opportunities within an hour doubles from 11 to 21 percent and from 20 to 42 percent respectively. The analysis also finds that spatial layouts that maximize the number of households that have access to a minimum share of jobs, through a more even jobs-housing balance, come at the expense of average accessibility. This result is interpreted as a trade-off between inclusive and efficient labor markets. Document type: Book

Abstract

Urban food waste in the U.S. is almost exclusively bound for landfills, with significant environmental and the economic consequences. Contrary to this linear flow, cities across the developed world are implementing organics collection programs (OCP) that transform waste into a resource. These systems convert excess food into inputs (e.g. biofuel or soil amendment) for other processes (i.e. food and energy production, water reclamation) thereby approximating naturally occurring closed-loop nutrient systems. However, efforts to address the flow of food waste into landfills have largely focused on technical solutions that alter the waste management systems of provision, largely ignoring the social aspects of food waste generation and source separation. Drawing on the Theory of Planned Behavior and concepts from social marketing research, results from longitudinal repeated-measures experiments indicate that providing supportive infrastructure is necessary for residents to act on their "intention" to divert food waste from landfills. The experiments are also the first to confirm that communicating the new community norms of separation in the context of a new OCP will increase separation behavior. In sum, closing the loop on urban food systems demands transformations of the systems of provision as well as the social aspects of waste systems. This research traces the evolution of organic waste policy on two continents using problem-framing as a lens through which to understand how different characterizations of food waste as a problem (i.e. as one of disposal efficiency, risk management or value recovery) result in different policy responses with varying degrees of linearity in urban food material flows. This dissertation contends that successfully closing the loop on urban food systems will demand new problem-framing that employs systems-thinking at the highest levels of policy-making, transformations of both the systems of provision and social practices, and an understanding of the relationship between social and natural systems (i.e. socio-ecological relationships).

Abstract

This study aims to quantify the impact of black carbon from inland shipping on air quality, expressed as elemental carbon (EC) near inland waterways in The Netherlands. Downwind measurements of particle numbers and EC were used to establish emission factors for EC from inland shipping using inverse modelling. These emission factors were combined with data on energy consumption to derive annual average emissions rates for all Dutch waterways. A line source model was applied to compute the contribution of inland shipping to annual average EC concentrations for around 140,000 people living within 200m of busy waterways in The Netherlands. The results showed that they are exposed to additional EC concentrations of up to 0.5μgEC per m3 depending on the shipping volume and distance from the waterway. In view of the envisaged growth in water transport, this underlines the need to reduce combustion emissions from inland shipping. Targeting "gross" polluters may be the most effective approach since 30% of ships cause more than 80% of the total emissions. © 2014 Elsevier Ltd.

Abstract

n innovative risk analysis model has been developed in order to quantify and analyse safety risks related to loss-of- containment scenarios in the pipeline transport of CO2. The risk model integrates the identified failure modes, consequence estimates and emergency response, producing consistent risk profiles based on complete outcome spaces and for different system design choices. The method involves integration in a Bayesian Belief Network (BN) of analytical equations for gas dispersion combined with statistics and expert estimates of particularly uncertain variables. Future failure initiators, scenarios and impacts are captured in a graphical structure which represents and calculates the effects of common causes. The test case for the integrated risk model will be a large CO2 capture and transport network at the Le Havre industrial zone with export to Rotterdam. The primary relative advantages of the BN risk model approach are discussed.

Abstract

Heavy metals constitute an important group of persistent toxic pollutants occurring in ambient air and other media. One of the suspected sources of these metals in the atmosphere is combustion of transport fuels in road vehicles. However estimates of the emissions of these metals from road vehicles as reported in national emission inventories show a very high variability in emission factors used. This paper provides high quality data on concentrations of heavy metals in fuels and derives default emission factors from these. The paper discusses these values against the emission estimates presently reported by the Parties to the LRTAP Convention. The measured concentrations of heavy metals in petrol and diesel fuel show a high variability between different samples taken at gas stations throughout Europe. Metal concentrations in road transport fuels vary over two orders of magnitude, but all remain in the ppb region (a few tenths of a ppb to a few hundred ppb for all metals). The frequency distributions of the measurements could be approximated by lognormal distributions. We could not detect a significant difference between samples from different countries. The fuel based emission factors as derived in this study are compared with those related to lubricant use as published by Winther and Slentø (2010). For most HMs studied here, this would lead to an two to fourfold increase of the tailpipe emissions as derived from the fuel concentrations. The emission factors, including 95 percent confidence intervals were derived from a statistical analysis of the survey data. The proposed emission factors were generally lower than previously published emission factors. National emissions of heavy metals from vehicle exhaust, estimated in this study therefore are in many cases considerably lower than those reported by the countries for this source.