Remanufacturing: Impacts of Sacrificial Cylinder Liners

2004 ◽  
Vol 127 (3) ◽  
pp. 687-697 ◽  
Author(s):  
Malte Krill ◽  
Deborah L. Thurston

Remanufacturing offers the potential for simultaneously recovering the economic value of manufactured components and improving the environment. Some design features make remanufacturing less expensive and/or increase the proportion of components that can be remanufactured. For example, sacrificial components can be used to protect key parts from wear. However, trade-offs are sometimes involved, and product designers need tools to support design for remanufacturing. This paper presents models for estimating the costs and environmental impacts of employing sacrificial components (cylinder liners) in engine blocks. These models are incorporated into a spreadsheet-based design decision tool. Three illustrative examples demonstrate that (1) remanufacturing lowers overall costs when two life cycles are considered, (2) sacrificial cylinder liners should be employed for small (2 L) engines, and their superiority increases with multiple remanufacturing cycles, and (3) for large engines (5.3 L) using cylinder liners is equally preferred to not using them, with respect to both overall cost and environmental impacts.

Author(s):  
Malte Krill ◽  
Deborah Thurston

Remanufacturing presents tremendous potential for recovering the economic value of manufactured components, and improving the environment. Some design features make remanufacturing less expensive, and/or increase the proportion of components that can be remanufactured. For example, sacrificial components can be used to protect key parts from wear. However, tradeoffs are sometimes involved, and product designers need tools to support design for remanufacturing. This paper presents models for estimating the costs and environmental impacts of employing sacrificial components (cylinder liners) in engine blocks. These models are incorporated into a spreadsheet-based design decision tool. Three illustrative examples demonstrate that 1) remanufacturing lowers overall costs when two lifecycles are considered, 2) sacrificial cylinder liners should be employed for small (2 liter) engines, and their superiority increases with multiple remanufacturing cycles, and 3) for large engines (5.3 liter) using cylinder liners is equally preferred to not using them, with respect to both overall cost and environmental impacts.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1313 ◽  
Author(s):  
Jonovan Van Yken ◽  
Naomi J. Boxall ◽  
Ka Yu Cheng ◽  
Aleksandar N. Nikoloski ◽  
Navid R. Moheimani ◽  
...  

Electronic e-waste (e-waste) is a growing problem worldwide. In 2019, total global production reached 53.6 million tons, and is estimated to increase to 74.7 million tons by 2030. This rapid increase is largely fuelled by higher consumption rates of electrical and electronic goods, shorter life cycles and fewer repair options. E-waste is classed as a hazardous substance, and if not collected and recycled properly, can have adverse environmental impacts. The recoverable material in e-waste represents significant economic value, with the total value of e-waste generated in 2019 estimated to be US $57 billion. Despite the inherent value of this waste, only 17.4% of e-waste was recycled globally in 2019, which highlights the need to establish proper recycling processes at a regional level. This review provides an overview of global e-waste production and current technologies for recycling e-waste and recovery of valuable material such as glass, plastic and metals. The paper also discusses the barriers and enablers influencing e-waste recycling with a specific focus on Oceania.


Author(s):  
Jay Ling ◽  
Christiaan J. J. Paredis

An important element of successful engineering design is the effective management of resources to support design decisions. Design decisions can be thought of as having two phases—a formulation phase and a solution phase. As part of the formulation phase, engineers must decide which models to use in support of design decisions. Although more accurate models typically lead to better decisions, they also cost more. The question therefore is: Which model provides the best cost-benefit trade-off? In this paper, we focus in particular on the situation in which the systematic error in the models can be bounded by an interval. Based on principles of information economics, the interval-based model error results in bounds on the expected economic value of using a particular model in support of a certain design decision. The decision maker can then select the model that provides the best overall value, considering both the expected benefits resulting from the decision and the cost of the decision-making process. The approach is illustrated with the design of an I-beam structure.


2021 ◽  
Vol 13 (5) ◽  
pp. 2525
Author(s):  
Camila López-Eccher ◽  
Elizabeth Garrido-Ramírez ◽  
Iván Franchi-Arzola ◽  
Edmundo Muñoz

The aim of this study is to assess the environmental impacts of household life cycles in Santiago, Chile, by household income level. The assessment considered scenarios associated with environmental policies. The life cycle assessment was cradle-to-grave, and the functional unit considered all the materials and energy required to meet an inhabitant’s needs for one year (1 inh/year). Using SimaPro 9.1 software, the Recipe Midpoint (H) methodology was used. The impact categories selected were global warming, fine particulate matter formation, terrestrial acidification, freshwater eutrophication, freshwater ecotoxicity, mineral resource scarcity, and fossil resource scarcity. The inventory was carried out through the application of 300 household surveys and secondary information. The main environmental sources of households were determined to be food consumption, transport, and electricity. Food consumption is the main source, responsible for 33% of the environmental impacts on global warming, 69% on terrestrial acidification, and 29% on freshwater eutrophication. The second most crucial environmental hotspot is private transport, whose contribution to environmental impact increases as household income rises, while public transport impact increases in the opposite direction. In this sense, both positive and negative environmental effects can be generated by policies. Therefore, life-cycle environmental impacts, the synergy between policies, and households’ socio-economic characteristics must be considered in public policy planning and consumer decisions.


Author(s):  
Richard Steinberg ◽  
Raytheon Company ◽  
Alice Diggs ◽  
Raytheon Company ◽  
Jade Driggs

Verification and validation (V&V) for human performance models (HPMs) can be likened to building a house with no bricks, since it is difficult to obtain metrics to validate a model when the system is still in development. HPMs are effective for performing trade-offs between the human system designs factors including number of operators needed, the role of automated tasks versus operator tasks, and member task responsibilities required to operate a system. On a recent government contract, our team used a human performance model to provide additional analysis beyond traditional trade studies. Our team verified the contractually mandated staff size for using the system. This task demanded that the model have sufficient fidelity to provide information for high confidence staffing decisions. It required a method for verifying and validating the model and its results to ensure that it accurately reflected the real world. The situation caused a dilemma because there was no actual system to gather real data to use to validate the model. It is a challenge to validate human performance models, since they support design decisions prior to system. For example, crew models are typically inform the design, staffing needs, and the requirements for each operator’s user interface prior to development. This paper discusses a successful case study for how our team met the V&V challenges with the US Air Force model accreditation authority and successfully accredited our human performance model with enough fidelity for requirements testing on an Air Force Command and Control program.


Author(s):  
Marc Jaxa-Rozen ◽  
Astu Sam Pratiwi ◽  
Evelina Trutnevyte

Abstract Purpose Global sensitivity analysis increasingly replaces manual sensitivity analysis in life cycle assessment (LCA). Variance-based global sensitivity analysis identifies influential uncertain model input parameters by estimating so-called Sobol indices that represent each parameter’s contribution to the variance in model output. However, this technique can potentially be unreliable when analyzing non-normal model outputs, and it does not inform analysts about specific values of the model input or output that may be decision-relevant. We demonstrate three emerging methods that build on variance-based global sensitivity analysis and that can provide new insights on uncertainty in typical LCA applications that present non-normal output distributions, trade-offs between environmental impacts, and interactions between model inputs. Methods To identify influential model inputs, trade-offs, and decision-relevant interactions, we implement techniques for distribution-based global sensitivity analysis (PAWN technique), spectral clustering, and scenario discovery (patient rule induction method: PRIM). We choose these techniques because they are applicable with generic Monte Carlo sampling and common LCA software. We compare these techniques with variance-based Sobol indices, using a previously published LCA case study of geothermal heating networks. We assess eight environmental impacts under uncertainty for three design alternatives, spanning different geothermal production temperatures and heating network configurations. Results In the application case on geothermal heating networks, PAWN distribution-based sensitivity indices generally identify influential model parameters consistently with Sobol indices. However, some discrepancies highlight the potentially misleading interpretation of Sobol indices on the non-normal distributions obtained in our analysis, where variance may not meaningfully describe uncertainty. Spectral clustering highlights groups of model results that present different trade-offs between environmental impacts. Compared to second-order Sobol interaction indices, PRIM then provides more precise information regarding the combinations of input values associated with these different groups of calculated impacts. PAWN indices, spectral clustering, and PRIM have a computational advantage because they yield stable results at relatively small sample sizes (n = 12,000), unlike Sobol indices (n = 100,000 for second-order indices). Conclusions We recommend adding these new techniques to global sensitivity analysis in LCA as they give more precise as well as additional insights on uncertainty regardless of the distribution of the model outputs. PAWN distribution-based global sensitivity analysis provides a computationally efficient assessment of input sensitivities as compared to variance-based global sensitivity analysis. The combination of clustering and scenario discovery enables analysts to precisely identify combinations of input parameters or uncertainties associated with different outcomes of environmental impacts.


Buildings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 105 ◽  
Author(s):  
Nadia MIRABELLA ◽  
Martin RÖCK ◽  
Marcella Ruschi Mendes SAADE ◽  
Carolin SPIRINCKX ◽  
Marc BOSMANS ◽  
...  

Globally, the building sector is responsible for more than 40% of energy use and it contributes approximately 30% of the global Greenhouse Gas (GHG) emissions. This high contribution stimulates research and policies to reduce the operational energy use and related GHG emissions of buildings. However, the environmental impacts of buildings can extend wide beyond the operational phase, and the portion of impacts related to the embodied energy of the building becomes relatively more important in low energy buildings. Therefore, the goal of the research is gaining insights into the environmental impacts of various building strategies for energy efficiency requirements compared to the life cycle environmental impacts of the whole building. The goal is to detect and investigate existing trade-offs in current approaches and solutions proposed by the research community. A literature review is driven by six fundamental and specific research questions (RQs), and performed based on two main tasks: (i) selection of literature studies, and (ii) critical analysis of the selected studies in line with the RQs. A final sample of 59 papers and 178 case studies has been collected, and key criteria are systematically analysed in a matrix. The study reveals that the high heterogeneity of the case studies makes it difficult to compare these in a straightforward way, but it allows to provide an overview of current methodological challenges and research gaps. Furthermore, the most complete studies provide valuable insights in the environmental benefits of the identified energy performance strategies over the building life cycle, but also shows the risk of burden shifting if only operational energy use is focused on, or when a limited number of environmental impact categories are assessed.


2019 ◽  
pp. 623-643 ◽  
Author(s):  
Max Craglia ◽  
Katarzyna Pogorzelska

Abstract In this chapter, we approach the economic value of Digital Earth with a broad definition of economic value, i.e., the measure of benefits from goods or services to an economic agent and the trade-offs the agent makes in view of scarce resources. The concept of Digital Earth has several components: data, models, technology and infrastructure. We focus on Earth Observation (EO) data because this component has been undergoing the most dramatic change since the beginning of this century. We review the available recent studies to assess the value of EO/geospatial/open data and related infrastructures and identify three main sets of approaches focusing on the value of information, the economic approach to the value of EO to the economy from both macro- and microeconomic perspectives, and a third set that aims to maximize value through infrastructure and policy. We conclude that the economic value of Digital Earth critically depends on the perspective: the value for whom, what purpose, and when. This multiplicity is not a bad thing: it acknowledges that Digital Earth is a global concept in which everyone can recognize their viewpoint and collaborate with others to increase the common good.


Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7864
Author(s):  
Sophie Adams ◽  
Donal Brown ◽  
Juan Pablo Cárdenas Álvarez ◽  
Ruzanna Chitchyan ◽  
Michael J. Fell ◽  
...  

In recent years, numerous studies have explored the opportunities and challenges for emerging decentralized energy systems and business models. However, few studies have focussed specifically on the economic and social value associated with three emerging models: peer-to-peer energy trading (P2P), community self-consumption (CSC) and transactive energy (TE). This article presents the findings of a systematic literature review to address this gap. The paper makes two main contributions to the literature. Firstly, it offers a synthesis of research on the social and economic value of P2P, CSC and TE systems, concluding that there is evidence for a variety of sources of social value (including energy independence, local benefits, social relationships, environmental responsibility and participation and purpose) and economic value (including via self-consumption of renewable electricity, reduced electricity import costs, and improved electricity export prices). Secondly, it identifies factors and conditions necessary for the success of these models, which include willingness to participate, participant engagement with technology, and project engagement of households and communities, among other factors. Finally, it discusses conflicts and trade-offs in the value propositions of the models, how the three models differ from one another in terms of the value they aim to deliver and some of the open challenges that require further attention by researchers and practitioners.


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