19 resultados para Environmental study
em Cambridge University Engineering Department Publications Database
Resumo:
The objective of this study was to compare the life-cycle environmental impacts of changed production structures for two consumer goods (high-density polyethylene (HDPE) shopping bags and beds) in Jamaica. A scenario technique was used to construct three alternative production structures for each product; each scenario reflecting an increase in local production in Jamaica which depended on an increased supply of input materials which may be sourced: (1) externally from overseas suppliers, (2) from post-consumer recycling, and (3) locally on the island of Jamaica. These three constructed scenarios were then compared to the existing supply chain or reference scenarios of the products. The results showed that for both case products the recycling scenario was most preferable for localising production, resulting in the lowest environmental impact. This was because the production of raw materials accounted for the largest effect on total environmental impact. As such, the most immediate environmental improvements were realised by lowering the production of virgin materials. © 2007 Elsevier Ltd. All rights reserved.
Resumo:
Geomembranes are one of the most commonly used geosynthetics in landfill liner systems. They retain the leachate produced by the waste and prevent leakage. Geomembranes may experience harsh environmental conditions such as extreme temperatures or earthquake loading. Earthquake loading can be an extreme loading case for landfills located in seismic regions. This study, based on dynamic centrifuge testing, investigates the effects of simulated earthquake loading on the tension experienced bythe geomembrane on a landfill slope. The landfill modeled in the dynamic centrifuge test was a municipal solid waste (MSW) landfill cell with a single geomembrane-clay liner system (45° side slope and 10 m slope length). The paper shows that moderate earthquake loading (base acceleration between 0.1g to 0.2g) can result in transient increases of around 20% in geomembrane tension, with permanent tension increases of around 5%.
Reducing Motor Vehicle Greenhouse Gas Emissions in a Non-California State: A Case Study of Minnesota
Resumo:
This paper reports some results from a major research project on the integration of environmental issues into design in the electrical and electronic industry. Product development practice and ecodesign methods were examined along with qualitative data from 19 manufacturers, using interviews and an action research methodology. A four-stage framework for ecodesign practice resulted: first, to make an environmental assessment from a life cycle viewpoint; then to communicate the analysis and collect feedback; thirdly to prioritize the environmental issues and finally to complete the design using relevant tools and methods. This 'ARPI' framework (analyse, report, prioritize, improve) applies to both strategic and operational levels. Initial testing of the framework in collaborating companies highlighted difficulties with communication with design teams; the role of 'ecodesign champions' is explained. Other challenges are the development of customized tools and the training of designers. The study concludes that the prioritization step is critical, as it simplifies and clarifies the tasks in design that take place after formulation of the specification. Copyright (C) 2000 John Wiley and Sons, Ltd. and ERP Environment.
Resumo:
The objective of this study was to identify challenges in civil and environmental engineering that can potentially be solved using data sensing and analysis research. The challenges were recognized through extensive literature review in all disciplines of civil and environmental engineering. The literature review included journal articles, reports, expert interviews, and magazine articles. The challenges were ranked by comparing their impact on cost, time, quality, environment and safety. The result of this literature review includes challenges such as improving construction safety and productivity, improving roof safety, reducing building energy consumption, solving traffic congestion, managing groundwater, mapping and monitoring the underground, estimating sea conditions, and solving soil erosion problems. These challenges suggest areas where researchers can apply data sensing and analysis research.