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821.
This paper deals with simplifying the environmental evaluation of an innovative sub-system related to the future complex system that will include it, by using evolving generic models built on a limited number of characteristics. For a complex system range, the evolving approach of the environmental modelling aims to generate a learning dynamics, to avoid the paralysing complexity induced in design by the valuation of many components according to many impact categories. Applied to the automotive sector, dendrograms are made with results of life cycle assessments (LCA) of 17 vehicles for 4 environmental indicators and on 3 life cycle steps. In an iterative process, a limit condition threshold on the resulting relative errors aims to cluster the vehicles. First, several calculation methods of dendrograms are tested. Second, the influence of the limit condition on the models is observed. Lastly, by simulating the vehicle population increase, the modelling capacity to evolve is tested. Five vehicle characteristics are sufficient to identify a model to be equivalent to the future vehicle. While the number of clusters is increased to simplify their identification with the system characteristics, the relative error variability increases too. The generic models are stable when adding LCA's results.  相似文献   
822.
滇池水环境治理的“调水”“活水”工程   总被引:1,自引:0,他引:1  
3.40MaB P,沿普渡河断裂发育的普渡河和沿小江断裂发育的小江均汇入到昆明盆地,形成滇池,并产生厚达千米的堆积物。早更新世晚期,金沙江贯通,导致普渡河和小江均倒流汇入金沙江,从而滇池处在金沙江、珠江和红河三大水系的风口的位置,滇池的补给系数变小,换水周期增长。近几十年来,污染物的输入和积累,导致滇池水质急剧下降。因此滇池水环境的整治,除了减少污染物的输入外,建议在禄劝县引掌鸠河的水入螳螂川,并流入滇池。滇池的集水面积增加到16 066 km2,滇池的入湖地表径流量就增加到26.64×108 m3,换水周期减少到197.2 d。与此同时使滇池在昆明向北流出,污染物不再扩散到整个湖泊,这样便可较好地解决滇池污染,整治滇池的水环境。  相似文献   
823.
固体火箭发动机全寿命环境载荷分析   总被引:2,自引:1,他引:1       下载免费PDF全文
目的对固体火箭发动机全寿命环境载荷情况进行分析,掌握其特性和变化规律。方法在分析固体火箭发动机使用环节主要环境载荷因素基础上,对实测获取的典型固体火箭发动机服役区域的环境载荷数据进行分析。依据固体火箭发动机全寿命服役历程情况,给出全寿命环境载荷的编制方法。结果根据发动机典型服役历程环境载荷特点和服役历程,可以有效掌握发动机全寿命周期内的环境载荷情况。结论该方法具有较好的可操作性,从而为固体火箭发动机结构完整性评价和寿命试验评估提供基础数据。  相似文献   
824.
准确评估种养一体化奶牛场的经济性能与环境绩效,是相关支持政策制定的基础,也是促进奶业低碳生产的关键.本文基于生命周期视角,对非种养一体化奶牛场(non-IPBS)和种养一体化奶牛场(IPBS)养殖过程中的温室气体排放、能源消耗、水消耗、土地占用等环境成本和经济效益进行评估.结果表明,non-IPBS生产1t标准牛奶(FPCM)的净收益为1427元,而IPBS的实际净收益提高7%,如果青贮玉米自给率从当前的32%提升到100%,则实际净收益将提高19%,同时,该净收益的提高率取决于耕地流转费用,临界点为14695元/hm2;相比non-IPBS,IPBS生产1tFPCM的温室气体排放、能源消耗、水消耗、土地占用分别减少6%、6%、5%、7%,如果青贮玉米自给率提升到100%,则相应减少16%、16%、11%、14%.IPBS在降低青贮玉米种植的化肥施用、解决养殖场粪便污染等方面优势明显,在提升养殖经济效益、降低温室气体排放等方面具有巨大潜力,值得推广.  相似文献   
825.
Life cycle assessment, LCA, has become a key methodology to evaluate the environmental performance of products, services and processes and it is considered a powerful tool for decision makers. Waste treatment options are frequently evaluated using LCA methodologies in order to determine the option with the lowest environmental impact. Due to the approximate nature of LCA, where results are highly influenced by the assumptions made in the definition of the system, this methodology has certain non-negligible limitations. Because of that, the use of LCA to assess waste co-incineration in cement kilns is reviewed in this paper, with a special attention to those key inventory results highly dependent on the initial assumptions made. Therefore, the main focus of this paper is the life cycle inventory, LCI, of carbon emissions, primary energy and air emissions. When the focus is made on cement production, a tonne of cement is usually the functional unit. In this case, waste co-incineration has a non-significant role on CO2 emissions from the cement kiln and an important energy efficiency loss can be deduced from the industry performance data, which is rarely taken into account by LCA practitioners. If cement kilns are considered as another waste treatment option, the functional unit is usually 1 t of waste to be treated. In this case, it has been observed that contradictory results may arise depending on the initial assumptions, generating high uncertainty in the results. Air emissions, as heavy metals, are quite relevant when assessing waste co-incineration, as the amount of pollutants in the input are increased. Constant transfer factors are mainly used for heavy metals, but it may not be the correct approach for mercury emissions.  相似文献   
826.
827.
China is the largest steel producer and consumer around the world. Quantifying the Chinese steel flow from cradle to grave can assist this industry to fully understand its historical status and future options on production route transformation, capacity planning, scrap availability, resource and energy consumption. With the help of the systematic methods combined dynamic MFA (material flow analysis) with scenario analysis, the Chinese steel cycle during the first half of the 21st century was quantified and several thought-provoking conclusions were draw. In the past decade, lots of pig iron or molten iron was fed into EAF (electric arc furnace) and the scrap usage of EAF fluctuated slightly. Thus, the real scrap-EAF route share is much lower than the EAF production share. On the other hand, we reconfirmed that the scrap supply in China will rise significantly in the future. Meanwhile, the secondary production route share will grow sharply and exceed primary production share before or after 2050 depending on our options. The scrap recycling rate and construction's lifetime play a vital role in this trend. In the end, an intensive discussion on production capacities’ adjustment and energy and resource consumption was conducted and relative policy suggestions were given. It is worth noting that scrap usage is crucial to future energy saving and emissions reduction of Chinese steel sector and its energy consumption might peak as early as 2015.  相似文献   
828.
The present world is facing problems like rapid depletion of natural resources and undesired environmental changes on a global scale. Manufacturing organisations are realising the importance of mitigating the present crisis and are adopting sustainable manufacturing principles. Since it is important to achieve sustainable manufacturing, sustainability assessment models were developed. Sustainability assessment models have their own drawbacks and may not provide clear scope for complete sustainable development. A system approach has been developed to overcome this shortcoming by integrating various sustainability assessment models that are already in practice. This article reports the advantages of collecting the advantages of individual sustainability assessment models and how the implementation of the integrated approach has helped to identify the current sustainability level and the scope for future developments in an automotive industry.  相似文献   
829.
Over the last three decades, new concepts, strategies, frameworks and systems have been developed to tackle the sustainable development issue. This paper reviews the challenges, perspectives and recent advances in support of sustainable production operations decision-making. The aim of this review is to provide a holistic understanding of advanced scientific analysis methodologies for the evaluation of sustainability, to provide efficient decision support. Over 100 publications have been analysed, and a characterisation of state-of-the-art sustainability analysis methodologies has been produced, which includes life cycle assessment and multi-criteria decision analysis (MCDA), along with their applications to three key areas of production operations: sustainable design, sustainable manufacture and sustainable supply chain management. Distribution of existing work is discussed and future research directions are elicited from the literature. The paper finds three trends in supporting sustainable production operations decisions: (a) sustainability analysis has moved to whole life cycle assessment from single-stage assessment, (b) sustainability analysis has shifted away from single criterion to MCDA and (c) sustainability analysis has evolved from stand-alone approaches to integrated systematic methodologies. The paper concludes that integrated sustainability analysis can provide more efficient and effective support to complex decision-making in sustainable production operations.  相似文献   
830.
The power sector in Thailand is the largest contributor to CO2 emissions. There is high potential to mitigate CO2 emission via alternative power generating plants. Alternative plants considered in this study include nuclear plants, integrated gasification combined cycle plants, biomass-based plants and supercritical thermal power plants. The biomass-based plants considered here are fueled with four types of biomass; paddy husk, municipal solid waste (MSW), fuel wood and corncob. The methodology for the optimal expansion plan of the power generating system over the planning horizon is based on the least-cost approach. The results from the least-cost planning analyses show that the nuclear alternative has the highest potential to mitigate not only CO2 but also other airborne emissions. Moreover, the nuclear option is the most effective abatement strategy for CO2 reduction due to its negative incremental cost of CO2 reduction.  相似文献   
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