A scalable life cycle inventory of an automotive power electronic inverter unit—part I: design and composition

The International Journal of Life Cycle Assessment - A scalable life cycle inventory (LCI) model, which provides mass composition and manufacturing data for a power electronic inverter unit...     

A scalable life cycle inventory of an automotive power electronic inverter unit—part II: manufacturing processes

Purpose

A scalable life cycle inventory (LCI) model, which provides mass composition and gate-to-gate manufacturing data for a power electronic inverter unit intended for controlling electric vehicle propulsion motors, was developed. The purpose is to fill existing data gaps for life cycle assessment (LCA) of electric vehicles. The model comprises new and easy-to-use data with sufficient level of detail to enable proper component scaling and in-depth analysis of inverter units. The aim of this article (part II) is to describe the modeling of all production steps and present new datasets. Another objective is to explain the strategies for data collection, system boundaries, and how unit process datasets were made to interact properly with the scalable design model (part I).

Methods

Data for the manufacturing of the inverter unit was collected from a variety of literature, technical specifications, factory data, site visits, and expert interviews. The model represents current levels of technology and modern industrial scale production. Industry data dates back to 2012. Some older literature is referred to, but only if it was found to remain relevant. Upstream, new data has been gathered to the point where the Ecoinvent database can be used to model a full cradle-to-gate inventory. To make the LCI model easy to use, each flow crossing the system boundary is reported with a recommended linked flow to this database.

Results and discussion

The screening and modeling of manufacturing inverter units resulted in a substantial compilation of new inventory data. In close integration with the design model, which is scalable in size over a range of 20–200 kW in nominal power and 250–700 V in DC system voltage (part I), it forms a comprehensive scalable LCI model of a typical automotive power electronic inverter unit intended for traction motor control. New production data covers electroplating of gold, electro-galvanization, machining and anodizing of aluminum, ceramic substrate fabrication, direct copper bonding, photoimaging and regenerative etching, power module assembly with a two-step soldering process, and the assembly of automotive printed circuit boards.

Conclusions

Interviews with experts were found to be vital for effective data collection and the reporting of details a key to maintaining data usability over time, for reuse, rework, and criticism by other LCA practitioners.

     

Cancer: A matter of life cycle?

In the last decade, the concept of "cancer stem cells" has emerged, recognised by the fact that only a small fraction of tumour cells appears to retain the stem cell properties of self-renewal and unlimited proliferation. At the same time, it is well known that cancer is an age-related disease developing at the limit of proliferating cell senescence. The apparent need to link senescence and the capacity for self-renewal has lead some authors to suggest that cancers develop from amongst senescing stem cells. However, an alternative solution has recently been proffered by Sundaram M, Guernsey DL, Rajaraman MM, Rajaraman R [Neosis: a novel type of cell division in cancer. Cancer Biol Ther 2004;3:207-18], who suggest that stemness may be a transient, cyclic property afforded by de-polyploidisation of senescing cells which have undergone polyploidisation. In this mini-review, we attempt to reconcile both of these views by the idea that cycling polyploidy intermitting senescence and rejuvenation may be features of a life cycle analogous to the life cycles of certain unicellular organisms. Furthermore, we suggest that mitotic catastrophe may represent a mechanism through which the cell can switch from the usual mitotic cell-cycle to this evolutionarily conserved life cycle. Intriguingly, some most recent data suggest that cell senescence may be reversible and that stem cells are tolerant to polyploidy caused by genotoxic stress.     

Extending life cycle assessment normalization factors and use of machine learning – A Slovenian case study

Within a life cycle assessment (LCA), normalization is an essential part for interpretation. In Europe, only the European Union normalization factors (EU NFs), with 2000 as the reference year, are available for LCA practitioners, although they work on a regional level. The hypothesis of this research was based on the assumption that some regional NFs deviate from the EU NFs due to unique regional profiles, or because of previously omitted or generalized human impact. In this particular case study set in Slovenia has been tested. By working on the ReCiPe 1.08 life cycle impact assessment methodology, 18 impact categories were investigated, and an additional 3 were added: electromagnetic radiation, light pollution and electric use. To meet practitioners’ needs, the most up-to-date inventory data was used with the reference years of 2007–2012. Out of 440 environmental interventions that were investigated, 139 had no characterization factors (CFs), 97 were estimated using machine learning and 42 had to be omitted. The final result confirmed our hypothesis. Twenty NFs were compared with the EU NFs, and the results have shown that on average, the NFs differ by a factor of 9.76 (median = 1.65). The reasons for the high deviation are due to natural land transformation, and ionising radiation, toxicological and ecotoxicological impact categories; where there are major data gaps in the CFs. The primary concern of the research was data availability for toxicological and ecotoxicological parameters for toxicity-related emissions, and the fact that original CFs covered only 50.25% of plant protection products used in Slovenia. Toxicological and ecotoxicological uncertainties were illustrated by comparing four different results. Future studies should be focused on the use of machine learning to provide the next generation of CFs and to go beyond the CFs’ damage-oriented assessment. Remediation should be the new endpoint category and its units should be Joules.     

A graphical representation for consequential life cycle assessment of future technologies—Part 2: two case studies on choice of technologies and evaluation of technology improvements

Purpose  

To construct future visions of how innovative technologies should be used in the envisioned sustainable society while being aware of system-wide environmental impacts, consequential life cycle assessment (c-LCA) is useful. To systematically evaluate the technologies being aware of uncertainties in the choice of technologies made in the future, in this article, we propose a novel graphical representation for theoretical range of impacts that contain results from c-LCA studies. This approach allows analyses of the consequences of technology introduction without conducting a detailed modeling of consequences.     

Life cycle thinking in small and medium enterprises: the results of research on the implementation of life cycle tools in Polish SMEs—Part 3: LCC-related aspects

Purpose

This article is the third of a series of articles presenting the results of research on the implementation of life cycle management tools in small- and medium-sized companies in Poland. The purpose of the three-part series of articles is to present the results of research on the implementation of life cycle tools in Polish small and medium enterprises (SMEs). This work is part of a project financed by the Polish Agency for Enterprise Development (PAED) which began in February 2011. It was carried out by the Wielkopolska Quality Institute—a business environment institution associated with the Polish Centre for LCA (PCLCA). The main practical objective of the project was to support SMEs in their business development, e.g. by expanding their horizons beyond the sphere of their operation and identifying new areas for the improvement and promotion of the products and services on offer. The specific objective of the analysis involving the assessment of life-cycle costs of products and services was an attempt to answer the question to determine whether the assessment carried out in accordance with the life-cycle cost (LCC) methodology is a good tool for cost management in this type of business. Part 3 describes the results of studies on the assessment of the implementation of LCC in SMEs conducted in 50 companies involved in the project.

Methods

In order to assess the effectiveness of the project and the effectiveness of the implementation of LCA and LCC, a survey was conducted of small- and medium-sized businesses where the implementation works had been fully completed. In total, 50 organisations agreed to participate in the LCC survey (while 46 in the LCA—part 2 paper), which was 71 % of all the companies where the LCA and LCC studies had been carried out within the project. The survey was conducted using individual in-depth interviews. Questions to the representatives of the companies referred both to aspects of their operating in the market (characteristics of a company, its market share, management systems, environmental policy, suppliers, clients) and the implementation of their environmental service (assessment of its effectiveness, motivation, difficulties in its implementation), as well as opinions on the potential applications of LCA in their current operations.

Results and discussion

The experience and observations of LCC experts resulting from their cooperation with the analysed organisations are largely supported by the results of the survey. The overall impression gained from the project is that the small- and medium-sized enterprises considered have a problem with accepting and understanding the life-cycle perspective, and show limited interest in taking liability for environmental and cost aspects beyond the mandatory legal standards and boundaries of their business operations. Nevertheless, the LCC analyses aroused much bigger interest among the companies than the environmental due to the fact that the cost aspects in companies undergoing normal development are seen as an important source of information about the structure of the costs generated with respect to the products or services provided. It is important to note that a very important factor encouraging businesses to join the studies was the fact that they were cost-free. Moreover, the planned introduction of a new product onto the market was the argument that often influenced the decision to implement the LCC. The survey has shown that companies rarely perform cost analyses including all stages of the life cycle of a product or service. Although the awareness of the importance of conducting economic researches for the entire life cycle of a product or service is great, it turned out to be problematic to unambiguously define the practical use of such an analysis, at least at the present stage of development of the companies surveyed.

Conclusions

The results obtained in the survey indicate that in the case of simple products, with a short life cycle, complex cost analyses may seem less useful. For more complex products or services, with long periods of use, high reliability required, and high operating costs, the analyses presented are useful tools that increase the economic efficiency of the projects implemented. It appears that from the point of view of polish SMEs, the usefulness of an LCA is seen mainly from the angle of opportunities for cost reduction (preferably in business) and increased sales (marketing). A good solution would be to conduct relatively simple, but integrated LCA/LCC analyses in SMEs so that the companies would clearly see the economic effects of the proposed environmental improvements.     

Commentary on “Correction to: On the calculation of fuel savings through lightweight design in automotive life cycle assessments” by Koffler and Rohde-Brandeburger (2018)

The International Journal of Life Cycle Assessment -     

Carbon and water footprint of coffee consumed in Finland—life cycle assessment

The International Journal of Life Cycle Assessment - Coffee is one of the most widely grown cash crops globally, but there are few scientific articles on its carbon footprint and water scarcity...     

Medicine in Society—Part I: Change and Challenge

The Committee to Study the Role of Medicine of the California Medical Education and Research Foundation (CMERF) is grateful to Dr. Watts for the following paper which served as the philosophical basis for the Committee''s study and discussions. The Committee is also grateful to CMERF and to its president, James C. Doyle, for the encouragement and cooperation it has received in the course of its intensive study of a problem which is of great interest and concern to the medical profession of California.Dr. Watts'' background paper has served as a potent stimulus in directing the Committee''s attention to the continuing dialogue between medicine and society, and in focussing on problems and issues which will be the subject of the Committee''s Second Progress Report, excerpts from which are scheduled for publication in the next issue of California Medicine.     

The origin,composition and rates of organic nitrogen deposition: A missing piece of the nitrogen cycle?

Organic forms of nitrogen are widespread in the atmosphere and their deposition may constitute a substantive input of atmospheric N to terrestrial and aquatic ecosystems. Recent studies have expanded the pool of available measurements and our awareness of their potential significance. Here, we use these measurements to provide a coherent picture of the processes that produce both oxidized and reduced forms of organic nitrogen in the atmosphere, examine how those processes are linked to human activity and how they may contribute to the N load from the atmosphere to ecosystems. We summarize and synthesize data from 41 measurements of the concentrations and fluxes of atmospheric organic nitrogen (AON). In addition, we examine the contribution of reduced organic nitrogen compounds such as amino acids, bacterial/particulate N, and oxidized compounds such as organic nitrates to deposition fluxes of AON. The percentage contribution of organic N to total N loading varies from site to site and with measurement methodology but is consistently around a third of the total N load with a median value of 30% (Standard Deviation of 16%). There are no indications that AON is a proportionally greater contributor to N deposition in unpolluted environments and there are not strong correlations between fluxes of nitrate and AON or ammonium and AON. Possible sources for AON include byproducts of reactions between NO_x and hydrocarbons, marine and terrestrial sources of reduced (amino acid) N and the long-range transport of organic matter (dust, pollen etc.) and bacteria. Both dust and organic nitrates such as PAN appear to play an important role in the overall flux of AON to the surface of the earth. For estimates of organic nitrate deposition, we also use an atmospheric chemical transport model to evaluate the spatial distribution of fluxes and the globally integrated deposition values. Our preliminary estimate of the magnitude of global AON fluxes places the flux between 10 and 50 Tg of N per year with substantial unresolved uncertainties but clear indications that AON deposition is an important aspect of local and global atmospheric N budgets and deserves further consideration.     

Assessing freshwater use impacts in LCA: Part I—inventory modelling and characterisation factors for the main impact pathways

Background, aim and scope

Freshwater is a basic resource for humans; however, its link to human health is seldom related to lack of physical access to sufficient freshwater, but rather to poor distribution and access to safe water supplies. On the other hand, freshwater availability for aquatic ecosystems is often reduced due to competition with human uses, potentially leading to impacts on ecosystem quality. This paper summarises how this specific resource use can be dealt with in life cycle analysis (LCA).

Main features

The main quantifiable impact pathways linking freshwater use to the available supply are identified, leading to definition of the flows requiring quantification in the life cycle inventory (LCI).

Results

The LCI needs to distinguish between and quantify evaporative and non-evaporative uses of ‘blue’ and ‘green’ water, along with land use changes leading to changes in the availability of freshwater. Suitable indicators are suggested for the two main impact pathways [namely freshwater ecosystem impact (FEI) and freshwater depletion (FD)], and operational characterisation factors are provided for a range of countries and situations. For FEI, indicators relating current freshwater use to the available freshwater resources (with and without specific consideration of water ecosystem requirements) are suggested. For FD, the parameters required for evaluation of the commonly used abiotic depletion potentials are explored.

Discussion

An important value judgement when dealing with water use impacts is the omission or consideration of non-evaporative uses of water as impacting ecosystems. We suggest considering only evaporative uses as a default procedure, although more precautionary approaches (e.g. an ‘Egalitarian’ approach) may also include non-evaporative uses. Variation in seasonal river flows is not captured in the approach suggested for FEI, even though abstractions during droughts may have dramatic consequences for ecosystems; this has been considered beyond the scope of LCA.

Conclusions

The approach suggested here improves the representation of impacts associated with freshwater use in LCA. The information required by the approach is generally available to LCA practitioners

Recommendations and perspectives

The widespread use of the approach suggested here will require some development (and consensus) by LCI database developers. Linking the suggested midpoint indicators for FEI to a damage approach will require further analysis of the relationship between FEI indicators and ecosystem health.     

Life cycle inventory and impact assessment for an asphalt pavement road construction—a case study in Brazil

The International Journal of Life Cycle Assessment - Currently, there are no life cycle impact data available on the construction of road infrastructure in Brazil. This study aimed to determine...     

Creating a “family tree” on fertilizer inventory use in life cycle assessment of oil palm: visualization of earlier studies and its implications

The International Journal of Life Cycle Assessment - This review develops and applies a visualization method for understanding how chemical fertilizer inventory data, including greenhouse gas (GHG)...     

Formulation of Dacarbazine-Loaded Cubosomes—Part I: Influence of Formulation Variables

The purpose of this study was to investigate the combined influence of three-level, three-factor variables on the formulation of dacarbazine (a water-soluble drug) loaded cubosomes. Box–Behnken design was used to obtain a second-order polynomial equation with interaction terms to predict response values. In this study, the selected and coded variables X₁, X₂, and X₃ representing the amount of monoolein, polymer, and drug as the independent variables, respectively. Fifteen runs of experiments were conducted, and the particle size (Y₁) and encapsulation efficiency (Y₂) were evaluated as dependent variables. We performed multiple regression to establish a full-model second-order polynomial equation relating independent and dependent variables. A second-order polynomial regression model was constructed for Y₁ and confirmed by performing checkpoint analysis. The optimization process and Pareto charts were obtained automatically, and they predicted the levels of independent coded variables X₁, X₂, and X₃ (−1, 0.53485, and −1, respectively) and minimized Y₁ while maximizing Y₂. These corresponded to a cubosome formulation made from 100 mg of monoolein, 107 mg of polymer, and 2 mg with average diameter of 104.7 nm and an encapsulation efficiency of 6.9%. The Box–Behnken design proved to be a useful tool to optimize the particle size of these drug-loaded cubosomes. For encapsulation efficiency (Y₂), further studies are needed to identify appropriate regression model.Key words: Box–Behnken design, cubosomes, dacarbazine, formulation variables     

Correction to: Creating a “family tree” on fertilizer inventory use in life cycle assessment of oil palm: visualization of earlier studies and its implications

The International Journal of Life Cycle Assessment - The original version of this article unfortunately contained a mistake.     

Life cycle thinking in small and medium enterprises: the results of research on the implementation of life cycle tools in Polish SMEs—part 1: background and framework

Purpose

This article is the first of a series of articles presenting the results of research on the implementation of life cycle management tools in small- and medium-sized companies in Poland. This work is part of a project financed by the Polish Agency for Enterprise Development (PAED) which began in February 2011. It was carried out by the Wielkopolska Quality Institute—a business environment institution associated with the Polish Centre for Life Cycle Assessment (PCLCA). The main practical objective of the project was to support small and medium enterprises (SMEs) in their business development, e.g. by expanding their horizons beyond the sphere of their operation and identifying new areas for improvement and promotion of the products and services on offer. These publications are a voice in the discussion on the opportunities and pertinence of implementing life cycle thinking (LCT) in small- and medium-sized enterprises and an attempt to identify potential barriers arising from specific characteristics of SMEs which could hinder or even prevent the effective implementation of life cycle techniques. Part 1 presents the situation of SMEs in Poland, general objectives of the project and organisation of the survey process.

Methods

It was decided to carry out research on the effectiveness of the implementation of LCA and life cycle costing (LCC) in organisations that had received financial support for the implementation of life cycle techniques. Financial constraints, which might potentially be a reason for limited interest in LC techniques among SMEs in Poland, were taken into account. Thus, financial support provided an opportunity for the project to obtain information from a wide range of companies, not only from those companies that were particularly aware of the benefits of LC techniques or had a very good financial situation. Research based on the method of individual in-depth interviews was preceded by an analysis of literature showing the status of SMEs in Poland. Given the results, the project objectives were formulated and the ways of conducting the research were defined.

Results and discussion

The comparison of Polish SMEs with the same category of companies in the EU shows some similarities, such as the percentage of companies engaged in various businesses. The differences are expressed primarily in the financial potential, which in the case of Polish SMEs, is significantly smaller than the average in the EU. In the SME sector, there are less than half as many small businesses in Poland than in the EU. There are, however, many more microbusinesses in Poland. An evaluation of the prevalence of LCA and LCC techniques indicates that they are used by just 3 % of Polish SMEs, which is a very small proportion compared to the more than 50 % of SMEs taking any environmental measures. Information collected on specific details of Polish SMEs was used to identify the target group and develop a survey questionnaire which aimed to audit, among other things, the approach to environmental and economic analyses in the past and the approach to the LCA and/or LCC analyses that were implemented from the point of view of difficulties in their implementation and potential use of the results.

Conclusions

Part 1 of the series of articles demonstrates a marginal-scale dissemination of life cycle management techniques among Polish SMEs. Companies definitely prefer to introduce relatively simple solutions that do not require specialised knowledge or unnecessary costs, e.g. they introduce energy-saving bulbs and waste segregation. Only a small percentage of companies implement more complex activities, and most commonly, these are medium-sized companies with greater financial and human capital. So what should be done to make SMEs use life cycle techniques more frequently? Is it appropriate to make changes in the methodology and life cycle techniques as such, or should, rather, the incentive for SMEs to use LCT come from outside as a requirement of public institutions or suppliers in a supply chain? Answers to these questions are provided in the research conclusions presented in parts 2 and 3 of the series of articles.