387 research outputs found
Is Environmental Improvement in Automotive Component Design Highly Constrained?
This article investigates the influence of environmental, cost, and performance requirements on the design and management of automotive components through a case study involving instrument panels. To address the question of whether the environmental improvement of an instrument panel (IP) is highly constrained, a lifecycle inventory analysis is used to characterize the major environmental burdens associated with a generic IP defined from an average of three midsized vehicle models. A life-cycle cost analysis is also conducted to understand the market forces operating in the domains of the original equipment manufacturer; consumer; and end-of-life (EOL) vehicle managen. This study indicates that the existing set of environmental requirements, in conjunction with current cost drivers and the large set of manufacturing and use phase functional performance requirements, highly constrain opportunities for environmental improvement Specific improvement strategies-lightweighting, elimination of the painting operation, and reduction in material complexity-are examined in the context of existing system requirements. The near-term forecast for improvements is not optimistic. Innovation will continue in a slow and piecemeal fashion until requirements affecting the total vehicle system are significantly changedPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72780/1/jiec.1998.2.2.103.pd
Guidance for Improving Life-Cycle Design and Management of Milk Packaging
Life-cycle inventory and cost-analysis tools applied to milk packaging offer guidelines for achieving better environmental design and management of these systems. Life-cycle solid waste, energy, and costs were analyzed for seven systems including single-use and refillable glass bottles, single-use and refillable high-density polyethylene (HDPE) bottles, paperboard gable-top cartons, linear low-density polyethylene (LLDPE) flexible pouches, and polycarbonate refillable bottles on a basis of 1,000 gal of milk delivered. In addition, performance requirements were also investigated that highlighted potential barriers and trade-offs for environmentally preferable alternatives. Sensitivity analyses, indicated that material production energy, postconsumer solid waste, and empty container costs were key parameters for predicting life-cycle burdens and costs. Recent trends in recycling rates, tipping fees, and recycled materials market value had minimal effect on the results. Inventory model results for life-cycle solid waste and energy indicated the same rank order as results from previously published life-cycle inventory studies of container systems. Refillable HDPE and polycarbonate, and the flexible pouch were identified as the most environmentally preferable with respect to life-cycle energy and solid waste. The greater market penetration of these containers may be limited by performance issues such as empty container storage, handling requirements, and deposit fees for refillables, and resealability and puncture resistance for the pouch.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73503/1/108819899569322.pd
Life-Cycle Energy, Costs, and Strategies for Improving a Single-Family House
The life-cycle energy, greenhouse gas emissions, and costs of a contemporary 2,450 sq ft (228 m 3 ) U.S. residential home (the standard home, or SH) were evaluated to study opportunities for conserving energy throughout pre-use (materials production and construction), use (including maintenance and improvement), and demolition phases. Home construction and maintenance materials and appliances were inventoried totaling 306 metric tons. The use phase accounted for 91% of the total life-cycle energy consumption over a 50-year home life. A functionally equivalent energy-efficient house (EEH) was modeled that incorporated 11 energy efficiency strategies. These strategies led to a dramatic reduction in the EEH total life-cycle energy; 6,400 GJ for the EEH compared to 16,000 GJ for the SH. For energy-efficient homes, embodied energy of materials is important; pre-use energy accounted for 26% of life-cycle energy. The discounted (4%) life-cycle cost, consisting of mortgage, energy, maintenance, and improvement payments varied between 426,700 and 454,300 for a SH using four energy price forecast scenarios. In the case of the EEH, energy cost savings were offset by higher mortgage costs, resulting in total life-cycle cost between 434,100 and 443,200. Life-cycle greenhouse gas emissions were 1,010 metric tons CO 2 equivalent for an SH and 370 metric tons for an EEH.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75688/1/108819800569726.pd
Role of life cycle assessment in sustainable aquaculture
As an alternative food source to wild fisheries, aquaculture shows a great potential to help meet the growing demand for seafood and animal protein. The expansion of aquaculture has been achieved partly by system intensification, which has drawn vast criticisms of aquaculture for its environmental, social and economic sustainability issues. Life cycle assessment (LCA) has become the leading tool for identifying key environmental impacts of seafood production systems. A LCA evaluates the sustainability of diverse aquaculture systems quantitatively from a cradleâtoâgrave perspective. It provides a scientific basis for analysing system improvement and the development of certification and ecoâlabelling criteria. Current efforts focus on integrating local ecological and socioâeconomic impacts into the LCA framework. A LCA can play an important role in informing decision makers in order to achieve more sustainable seafood production and consumption. This article reviews recent applications of LCA in aquaculture, compares the environmental performance of different aquaculture production systems, explores the potential of including biodiversity issues into LCA analysis and examines the potential of LCA in setting criteria for certification and ecoâlabelling.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98772/1/raq1080.pd
Inclusion of on-site renewables in design-stage building life cycle assessments
This paper investigates the inclusion of renewables in building life cycle assessments. On-site renewable electricity generation is increasingly common in the built environment, but existing guidance for the inclusion of these renewable systems in design-stage life cycle assessment is limited. The life cycle assessment of a building with 42.8 kWpeak solar photovoltaic array is used as a case study to investigate the effect of different assumptions on the assessment outcome. The case study results are then used to suggest good practice. The paper also highlights where further research is required to provide reliable design-stage assessments in future
The impact of âCash for Clunkersâ on greenhouse gas emissions: a life cycle perspective
One of the goals of the US Consumer Assistance to Recycle and Save (CARS) Act of 2009, more commonly known as 'Cash for Clunkers', was to improve the US vehicle fleet fuel efficiency. Previous studies of the program's environmental impact have focused mainly on the effect of improved fuel economy, and the resulting reductions in fuel use and emissions during the vehicle use phase. We propose and apply a method for analyzing the net effect of CARS on greenhouse gas emissions from a full vehicle life cycle perspective, including the impact of premature production and retirement of vehicles. We find that CARS had a one-time effect of preventing 4.4 million metric tons of CO2-equivalent emissions, about 0.4% of US annual light-duty vehicle emissions. Of these, 3.7 million metric tons are avoided during the period of the expected remaining life of the inefficient 'clunkers'. 1.5 million metric tons are avoided as consumers purchase vehicles that are more efficient than their next replacement vehicle would otherwise have been. An additional 0.8 million metric tons are emitted as a result of premature manufacturing and disposal of vehicles. These results are sensitive to the remaining lifetime of the 'clunkers' and to the fuel economy of new vehicles in the absence of CARS, suggesting important considerations for policymakers deliberating on the use of accelerated vehicle retirement programs as a part of the greenhouse gas emissions policy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85437/1/erl10_4_044003.pd
Dynamic Modeling of In-Use Cement Stocks in the United States
A dynamic substance-flow model is developed to characterize the stocks and flows of cement utilized during the 20th century in the United States, using the generic cement life cycle as a systems boundary. The motivation for estimating historical inventories of cement stocks and flows is to provide accurate estimates of contemporary cement in-use stocks in U.S. infrastructure and future discards to relevant stakeholders in U.S. infrastructure, such as the federal and state highway administrators, departments of transportation, public and private utilities, and the construction and cement industries. Such information will assist in planning future rehabilitation projects and better life cycle management of infrastructure systems. In the present policy environment of climate negotiations, estimates of in-use cement infrastructure can provide insights about to what extent built environment can act as a carbon sink over its lifetime. The rate of addition of new stock, its composition, and the repair of existing stock are key determinants of infrastructure sustainability. Based upon a probability of failure approach, a dynamic stock and flow model was developed utilizing three statistical lifetime distributionsâWeibull, gamma, and lognormalâfor each cement end-use. The model-derived estimate of the âin-useâ cement stocks in the United States is in the range of 4.2 to 4.4 billion metric tons (gigatonnes, Gt). This indicates that 82% to 87% of cement utilized during the last century is still in use. On a per capita basis, this is equivalent to 14.3 to 15.0 tonnes of in-use cement stock per person. The in-use cement stock per capita has doubled over the last 50 years, although the rate of growth has slowed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72233/1/JIEC_055_sm_SuppMat.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/72233/2/j.1530-9290.2008.00055.x.pd
Dynamic Life Cycle Modeling of Pavement Overlay System: capturing the impacts of users, construction, and roadway deterioration
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/84824/1/2007ISIEabstHan.pd
The application of life cycle assessment to design
This paper explores the practical application of life cycle assessment (LCA) to product system development. While life cycle assessment methods have been studied and demonstrated extensively over the last two decades, their application to product design and development has not been critically addressed. Many organizational and operational factors limit the integration of the three LCA components (inventory analysis, impact assessment and improvement assessment) with product development. Design of the product system can be considered a synthesis of individual decisions and choices made by the design team, which ultimately shape the system's environmental profile. The environmental goal of life cycle design is to minimize the aggregate environmental impacts associated with the product system. Appropriate environmental information must be supplied to decision makers throughout each stage of the development process to achieve this goal. LCA can serve as a source of this information, but informational requirements can vary as the design moves from its conceptual phase, where many design choices are possible, to its detailed design and implementation. Streamlined approaches and other tools, such as design checklists, are essential. The practical use of this tool in product development also depends on the nature and complexity of the product system (e.g. new vs. established), the product development cycle (time-to-market constraints), availability of technical and financial resources, and the design approach (integrated vs. serial). These factors will influence the role and scope of LCA in product development. Effective communication and evaluation of environmental information and the integration of this information with cost, performance, cultural and legal criteria will also be critical to the success of design initiatives based on the life cycle framework. An overview of several of these design initiatives will be presented.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31056/1/0000733.pd
Durable and Sustainable overlay with ECC
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/84760/1/Durable_and_sust_OL_w_ECC_official.pd
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