首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   51篇
  免费   2篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2019年   4篇
  2018年   1篇
  2017年   4篇
  2016年   5篇
  2015年   1篇
  2014年   4篇
  2013年   4篇
  2012年   1篇
  2011年   2篇
  2010年   2篇
  2009年   1篇
  2008年   2篇
  2007年   1篇
  2006年   4篇
  2005年   1篇
  2004年   5篇
  2003年   1篇
  2002年   2篇
  2001年   1篇
  2000年   1篇
  1991年   1篇
排序方式: 共有53条查询结果,搜索用时 15 毫秒
1.
The recycling of metals is widely viewed as a fruitful sustainability strategy, but little information is available on the degree to which recycling is actually taking place. This article provides an overview on the current knowledge of recycling rates for 60 metals. We propose various recycling metrics, discuss relevant aspects of recycling processes, and present current estimates on global end‐of‐life recycling rates (EOL‐RR; i.e., the percentage of a metal in discards that is actually recycled), recycled content (RC), and old scrap ratios (OSRs; i.e., the share of old scrap in the total scrap flow). Because of increases in metal use over time and long metal in‐use lifetimes, many RC values are low and will remain so for the foreseeable future. Because of relatively low efficiencies in the collection and processing of most discarded products, inherent limitations in recycling processes, and the fact that primary material is often relatively abundant and low‐cost (which thereby keeps down the price of scrap), many EOL‐RRs are very low: Only for 18 metals (silver, aluminum, gold, cobalt, chromium, copper, iron, manganese, niobium, nickel, lead, palladium, platinum, rhenium, rhodium, tin, titanium, and zinc) is the EOL‐RR above 50% at present. Only for niobium, lead, and ruthenium is the RC above 50%, although 16 metals are in the 25% to 50% range. Thirteen metals have an OSR greater than 50%. These estimates may be used in considerations of whether recycling efficiencies can be improved; which metric could best encourage improved effectiveness in recycling; and an improved understanding of the dependence of recycling on economics, technology, and other factors.  相似文献   
2.
The International Journal of Life Cycle Assessment - Scientific Life Cycle Assessment (LCA) literature provides some examples of LCA teaching in higher education, but not a structured overview of...  相似文献   
3.
The International Journal of Life Cycle Assessment - How to apply allocation in an life cycle assessment (LCA) is a long-running and controversial debate. Consensus seems to exist on the fact that...  相似文献   
4.

Purpose

The paper provides a late report from the United Nations Environment Program (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative workshop “Life Cycle Impact Assessment (LCIA)—where we are, trends, and next steps;” it embeds this report into recent development with regard to the envisaged development of global guidance on environmental life cycle impact assessment indicators and related methodologies.

Methods

The document is the output of the UNEP/SETAC Life Cycle Initiative’s workshop on “Life Cycle Impact Assessment—where we are, trends, and next steps.” The presentations and discussions held during the workshop reviewed the first two phases of the Life Cycle Initiative and provided an overview of current LCIA activities being conducted by the Initiative, governments and academia, as well as corporate approaches. The outcomes of the workshop are reflected in light of the implementation of the strategy for Phase 3 of the Life Cycle Initiative.

Results

The range of views provided during the workshop indicated different user needs, with regards to, amongst other things, the required complexity of the LCIA methodology, associated costs, and the selection of LCIA categories depending on environmental priorities. The workshop’s results signified a number of potential focus areas for Phase 3 of the Initiative, including capacity building efforts concerning LCIA in developing countries and emerging economies, the preparation of training materials on LCIA, the production of global guidance on LCIA, and the potential development of a broader sustainability indicators framework.

Conclusions

These suggestions have been taken into account in the strategy for Phase 3 of the Life Cycle Initiative in two flagship projects, one on global capability development on life cycle approaches and the other on global guidance on environmental life cycle impact assessment indicators. In the context of the latter project, first activities are being organized and planned. Moreover, UNEP has included the recommendations in its Rio + 20 Voluntary Commitments: UNEP and SETAC through the UNEP/SETAC Life Cycle Initiative commit to facilitate improved access to good quality life cycle data and databases as well as expanded use of key environmental indicators that allows the measurement and monitoring of progress towards the environmental sustainability of selected product chains.  相似文献   
5.

Purpose

To contribute to the upcoming United Nations Conference on Sustainable Development (Rio+20) in 2012 by introducing a life cycle sustainability assessment (LCSA) and showing how it can play a crucial role in moving towards sustainable consumption and production. The publication, titled Towards a Life Cycle Sustainability Assessment, and published by the UNEP/SETAC Life Cycle Initiative aims to show how three life cycle techniques—(environmental) LCA, S-LCA and LCC—can be combined as part of an over-arching LCSA.

Methods

The method was demonstrated by evaluating the characteristics of each phase for each life cycle technique. In defining the goal and scope of an LCSA, for example, different aspects should be taken into account to establish the aim of the study as well as the functional unit, system boundaries, impact category and allocation. Then, the data to be collected for the life cycle sustainability inventory can be either in a unit process or on an organisational level. They can also be quantitative or qualitative. Life cycle sustainability impact assessment should consider the relevance of the impacts as well as the perspective of stakeholders. The interpretation should not add up the results, but rather evaluate them jointly. In order to clarify the approach, a case study is presented to evaluate three types of marble according to the proposed method.

Results and discussion

The authors have identified that while LCSA is feasible, following areas need more development: data production and acquisition, methodological development, discussion about LCSA criteria (e.g. cutoff rules), definitions and formats of communication and dissemination of LCSA results and the expansion of research and applications combining (environmental) LCA, LCC and S-LCA. The authors also indicate that it is necessary to develop more examples and cases to improve user capacity to analyse the larger picture and therefore address the three dimensions or pillars of sustainability in a systematic way. Software and database providers are called for in order to facilitate user-friendly and accessible tools to promote LCSAs.

Conclusions

The application demonstrated that, although methodological improvements are still needed, important steps towards an overarching sustainability assessment have been accomplished. LCSA is possible and should be pursued; however, more efforts should be made to improve the technique and facilitate the studies in order to contribute to a greener economy.  相似文献   
6.
In recent literature, the concept of criticality aspires to provide a multifaceted risk assessment of resource supply shortage. However, most existing methodologies for the criticality assessment of raw materials are restricted to a fixed temporal and spatial reference system. They provide a snapshot in time of the equilibrium between supply and demand/economic importance and do not account for temporal changes of their indicators. The static character of criticality assessments limits the use of criticality methodologies to short‐term policy making of raw materials. In the current paper, we argue for an enhancement of the criticality framework to account for three key dynamic characteristics, namely changes of social, technical, and economic features; consideration of the spatial dimension in site‐specific assessments; and impact of changing governance frameworks. We illustrate how these issues were addressed in studies outside of the field of criticality and identify the dynamic parameters that influence resource supply and demand based on a review of studies that belong to the general field of resource supply and demand. The parameters are grouped in seven categories: extraction, social, economic, technical, policy, market dynamics, and environmental. We explore how these parameters were considered in the reviewed studies and propose ways and specific examples of addressing the dynamic effects in the criticality indicators. Furthermore, we discuss the current work on future scenarios to provide reference points for indicator benchmarks. The insights and guidelines derived from the review and our recommendations for future research set the foundations for an enhanced dynamic and site‐specific criticality assessment framework.  相似文献   
7.

Introduction

The European Commission is supporting the development of the International Reference Life Cycle Data System (ILCD). This consists primarily of the ILCD Handbook and the ILCD Data Network. This paper gives an insight into the scientific positions of business, governments, consultants, academics, and others that were expressed at this public consultation workshop.

Workshop focus

The workshop focused on four of the topics of the main guidance documents of the ILCD Handbook: (1) general guidance on life cycle assessment (LCA); (2) guidance for generic and average life cycle inventory (LCI) data sets; (3) requirements for environmental impact assessment methods, models and indicators for LCA; and (4) review schemes for LCA.

Workshop participation

This consultation workshop was attended by more than 120 participants during the 4 days of the workshop. Representatives came from 23 countries, from both within and outside the European Union.

Workshop structure

Approximately half of the participants were from business associations or individual companies. Another 20% were governmental representatives. Others came predominantly from consultancies and academia.

Results

This public consultation workshop provided valuable inputs into the overall ILCD Handbook developments as well as for further development. This paper focuses on some of the main scientific issues that were raised.  相似文献   
8.
The International Journal of Life Cycle Assessment - We observe a methodological gap for assessing impacts within the Area of Protection (AoP) Natural Resources in LCA with regard to concerns about...  相似文献   
9.
10.
Goal and Background  Geographical and technological differences in Life Cycle Inventory data are an important source for uncertainty in the result of Life Cycle Assessments. Knowledge on their impact on the result of an LCA is scarce, and also knowledge on how to manage them in an LCA case study. Objective  Goal of this paper is to explore these differences for municipal solid waste incinerator plants, and to develop recommendations for managing technological and geographical differences. Methodology  The paper provides a definition of technological and geographical differences, and analyses their possible impacts. In a case study, the differences are caused intentionally in ‘games’, by virtually transplanting incineration plants to a different location and by changing parameters such as the composition of the waste input incinerated. The games are performed by using a modular model for municipal solid waste incinerator plants. In each case, an LCA including an Impact Assessment is calculated to trace the impact of these changes, and the results are compared. Conclusions  The conclusions of the paper are two-fold: (1) reduce the differences in inventory data where their impact on the result is high; where it is possible reducing them to a great extent, and the effort for performing the change acceptable; in the case of incineration plants: Adapt the flue gas treatment, especially a possible DeNOx step, to the real conditions; (2) make use of modular process models that allow adapting plant parameters to better meet real conditions, but be aware of possible modelling errors. The paper invites the scientific community to validate the model used for a waste incinerator plant, and suggest putting up similar models for other processes, preferably those of similar relevance for Life Cycle Inventories.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号