LIFE CYCLE AND PRODUCTION OF CHIRONOMIDAE(DIPTERA) IN BIANDANTANG, A TYPICAL MACROPHYTIC LAKE (HUBEI, CHINA)

The life cycle and annual production of four dominant species of Chironomids ( Chironomus plumosus, Chironomus sp., Clinotanypus sp., Tokunagayusurika akamusi) were studied with samples taken monthly in Biandantang Lake at eight stations from April, 1996 to March, 1997. Instar frequency data showed C. plumosus was univoltine, while the other three were bivoltine. Production in wet weight (g/(m 2·a)) calculated by the size frequency method for each species were: C. plumosus, 2.663 ; Chironomus sp.,1.161 ;Clinotanypus sp., 0.270; T. akamusi , 1.476. Based on the mean standing stock, their P/B ratios were 3.2, 4.0, 6.2 and 4.4, respectively.

Life cycle assessment of oxygen-18 production using cryogenic oxygen distillation

In this study, life cycle assessment of oxygen-18 by using cryogenic distillation of oxygen is performed using SimaPro 8.3 software. Life cycle assessment is performed to understand the environmental profile and hotspots of this process in order to be used in design and development. Simulation of oxygen-18 process is executed by Hysys software, and the required inputs and outputs for inventory of life cycle were acquired. By doing life cycle assessment and considering achieved results after characterization and normalization of inventory data it has been investigated that in the majority of environmental impacts electricity consumption has a huge contribution relative to other parts of the system like liquefied oxygen production from air separation unit,required facilities for air separation and oxygen-18 units, and needed transportation. Also, among 17 impact categories investigated in ReCiPe impact assessment method, fossil depletion, climate change(human health),particulate matter formation, climate change(ecosystem), human toxicity, and metal depletion have the most contribution in entire environmental loads respectively. Furthermore, sensitivity analysis showed that changing life cycle impact assessment method from ReCiPe to IMPACT 2002+ has no significant effect on acquired results and results are confident. In addition, assumption of market for depleted oxygen from heavy isotopes which is withdrawn from top of distillation columns showed some positive effects compared to first case and environmental impacts resulted from liquefied oxygen production(feed) reduced but because of huge contribution of electricity consumption compared to other sections, this positive effect has no remarkable influence on entire environmental loads of product system.

A Study of the Bullwhip Effect for Short Life Cycle Products in Supply Chain Management

Shorter product life cycles present new dressed in supply chain literature. This research challenges to managing production and logistics not adequately adaddresses issues pertaining to the management of supply chains in a short life cycle environment. In this paper, we study the short life cycle environment; then we develop the ventory policy of the indirect manufacturer by explicitly using his demand us an output of the retailer＇s optimal inoptimal ordering policy. Finally, we also provide causes of the bullwhip effect in the context of short life cycle products.

Life cycle assessment of mobile phone housing

The life cycle assessment of the mobile phone housing in Motorola(China) Electronics Ltd. was carried out, in which materials flows and environmental emissions based on a basic production scheme were analyzed and assessed. In the manufacturing stage, such primary processes as polycarbonate molding and surface painting are included, whereas different surface finishing technologies like normal painting, electroplate, IMD and VDM etc. were assessed. The results showed that housing decoration plays a significant role within the housing life cycle. The most significant environmental impact from housing production is the photochemical ozone formation potential. Environmental impacts of different decoration techniques varied widely, for example, the electroplating technique is more environmentally friendly than VDM. VDM consumes much more energy and raw material. In addition, the results of two alternative scenarios of dematerialization showed that material flow analysis and assessment is very important and valuable in selecting an environmentally friendly process.

The study of the life cycle of technology assessment model

The life cycle of technology is one of the most important indexes to weigh up the risk of the investment to neo tech.There are so many uncertainties because it is conditioned by a lot of factors,we can not make a rational forecasting by traditional assessment method.So this paper gives a comprehensive consideration to the factors that influence production and makes some modification to production function, and establishes the life cycle of technology assessmet model by the method of fuzzy mathematics. So it quantifies the risk of investment.We can take it as one foundational index for the decision making of the investment.

Integrated Assessment of Environmental and Economic Performance of Chemical Products Using Analytic Hierarchy Process Approach

With the increasing public consciousness on environmental issues, chemical products and process de-signs require simultaneous satisfaction and compromise of environmental and economical requirements. To fulfill the two conflicting while complementary objectives, a systematic approach for life cycle design of a chemical product is proposed in this article. Multiattribute decision-making is adopted in a trade-off consideration of both technical economical evaluation and environmental impacts assessment using the analytic hierarchy process (AHP) approach. On the basis of an evaluation of the relative importance of the criteria multicriteria decision making is performed. In this study, an AHP model is used to derive single a criteria score by analyzing the environmental im-pact and life cycle cost of a product, respectively. And a fluctuant weight analysis is put forth to calculate the inte-grated index of the product to enable products to be ranked or selected intuitionally and conveniently. The proposed AHP model has been applied to a case study, a comparative study on chamber cleaning with NF3 and C2F6. The re-sults show that the proposed AHP model is capable of providing a rational and relevant evaluation.

Optimization of post-warranty sequential inspection for second-hand products

This paper considers an optimal sequential inspection schedule for a second-hand product after that the free nonrenewable warranty is expired. The length of warranty is prespecified and during the warranty period, the product is minimally repaired by the dealer when it fails. Following the expiration of the non-renewing warranty, the product is inspected and upgraded sequentially a fixed number of times at the expenses of the customer.At each inspection, the failure rate of the product is reduced proportionally so that the product is upgraded. The product is assumed to deteriorate as it ages and the replacement of the product occurs when a fixed number of inspections are rendered. In addition,the intervals between two successive inspections are assumed to decrease monotonically. The main objective of this paper is to determine the optimal improvement level to upgrade the product at each inspection so that the expected maintenance cost during the life cycle of the product is minimized from the perspective of the customer. Under the given cost structures, we derive an explicit formula to obtain the expected maintenance cost incurred during the life cycle of the product and discuss the method to find the optimal level of the improvement analytically in case the failure times follow the Weibull distribution. Numerical results are analyzed to observe the impact of relevant parameters on the optimal solution.

Assessing environmental impact of magnesium production using Pidgeon process in China

Based on the practice of magnesium production in China, a quantitative evaluation of the environment impact was carried out according to the theory and framework of life cycle assessment(LCA) study. The major gaseous pollutants including CO2, SO2, NOx, CH4, HF and particulates were calculated. The accumulative environmental performances of different energy use strategies and the characterization results, including abiotic depletion potential(ADP), global warming potential(GWP), acidification potential(AP) and human-toxicity potential(HTP) were compared. The results show that the direct emission of fuel combustion in the process is the major contributor to the pollutants emission of magnesium production. Global warming potential and acidification potential make the main contribution to the accumulative environmental impact. The different fuel use strategies in the practice of magnesium production cause much different impacts on the environmental performance. The accumulative environmental impact of coal burned directly is the highest, and that of producer-gas comes to the next, while that of coke-oven gas is the lowest.

The study of metal cycles in China

A model of Fe-flow in the life cycle of steel product was put forward and analyzed. Three important resource and environmental indicators for Fe-flow analysis,that is,steel scrap index,iron ore index and iron loss index were derived from this model. Illustrative examples,demonstrating the influence of the variation of steel output on steel scrap index and iron ore index were given. Case studies for estimating the values of steel scrap index of Japan,China and USA in the period of 1988-1997 were carried out. It was clarified that the main reason of severe deficiency in steel scraps for China's steel industry was its continued rapid growth. The study of iron,copper,zinc and lead cycle in China was carried out successfully according to this model.

Life cycle assessment as a prospective tool for sustainable agriculture and food planning at a local level

Owing to the far-reaching environmental consequences of agriculture and food systems,such as their contribution to climate change,there is an urgent need to reduce their impact.International and national governments set sustainability targets and implement corresponding measures.Nevertheless,critics of the globalized system claim that a territorial administrative scale is better suited to address sustainability issues.Yet,at the subnational level,local authorities rarely apply a systemic environmental assessment to enhance their action plans.This paper employs a territorial life cycle assessment methodology to improve local environmental agri-food planning.The objective is to identify significant direct and indirect environmental hotspots,their origins,and formulate effective mitigation strategies.The methodology is applied to the administrative department of Finistere,a strategic agricultural region in North-Western France.Multiple environmental criteria including climate change,fossil resource scarcity,toxicity,and land use are modeled.The findings reveal that the primary environmental hotspots of the studied local food system arise from indirect sources,such as livestock feed or diesel consumption.Livestock reduction and organic farming conversion emerge as the most environmentally efficient strategies,resulting in a 25%decrease in the climate change indicator.However,the overall modeled impact reduction is insufficient following national objectives and remains limited for the land use indicator.These results highlight the innovative application of life cycle assessment led at a local level,offering insights for the further advancement of systematic and prospective local agri-food assessment.Additionally,they provide guidance for local authorities to enhance the sustainability of planning strategies.

生命周期评价方法在印染产品环境影响分析中的应用

印染行业由于具有高水耗、高能耗和高污染的特性,成为全球范围内环境管理和可持续发展议程的重点行业。随着环境保护意识的增强和可持续发展需求的提升,生命周期评价方法可以评估产品从原材料获取、生产、使用到废弃全过程的环境影响,识别重点环境影响区域,提出相应的改进措施。在印染产品的环境影响中应用生命周期评价方法,可以通过详细的案例分析,定义目标和范围,执行生命周期清单分析,进行生命周期影响评估,并对结果进行解释。基于生命周期提出优化策略,可以为印染行业的环境影响减缓提供理论基础。

数字革命周期下新质生产力培育的机制和路径

新质生产力是数字革命下生产力现代化转型和跃升的最新体现。在新一轮数字革命的关键时点探讨新质生产力培育的机制和路径,要顺应数字革命迭代演变的规律,构建“技术—产业—生态”的新分析范式。数字革命会经历技术导入、融入渗透以及生态构建三个时期,首先以颠覆式数字创新形成技术创新簇群,为新质生产力培育注入新动能;其次以新兴数字产业和传统产业深度互动,为新质生产力培育提供支撑;最后以算网协同的基础设施体系,为新质生产力培育提供生态平台。在数字革命不同时期构建新型生产关系,一是要完善新型举国体制,提升国家创新体系整体效能;二是要转变产业政策导向,实现从“选择性”向“功能性”转型;三是要加快国家治理体系的数字化变革,形成多元协同的数字治理新格局。

生命周期评价在钢铁行业的应用及研究进展

钢铁行业是传统意义上的高能耗和高污染物排放行业。由于生命周期评价(LCA)可以很好地量化其潜在环境影响,找到更有效的清洁生产路径,在推动钢铁行业的绿色化、低碳化和高质量发展中得到了广阔应用。本文通过国内外文献回顾和统计分析,重点论述了LCA在钢铁行业以下3个方面的应用及研究进展:1)评估钢铁企业/钢铁产品在从原材料采掘开始到生产出厂过程中的环境影响,寻找企业/产品节能减排机会;2)评估清洁生产改进技术或方案的环境效应,为钢铁行业提升清洁生产水平提供决策依据;3)评估其作为“中间产品”对下游行业的环境影响贡献,促进全产业链的可持续发展。最后,提出了未来研究关注的3个重要方向,旨在进一步推动LCA在钢铁行业的研究和应用。

南北主食差异对家庭食物浪费碳足迹的影响——来自CHNS的经验证据

减少食物浪费是保障粮食安全、缓解全球气候变暖的重要举措。基于中国健康与营养调查(CHNS)和中国食品生命周期评估数据库(CFLCAD),从南北主食差异这一视角出发,基于生命周期理论分析中国居民家庭的食物浪费碳足迹。研究发现,中国居民家庭人均日食物浪费碳足迹为62.255 g CO^(2)eq。相比以小麦为主食的北方家庭(人均食物浪费碳足迹为53.704 g CO^(2)eq/d),以大米为主食的南方家庭有着更高的人均食物浪费碳足迹(69.628 g CO^(2)eq/d)。此外,显著影响家庭食物浪费碳足迹的还有户主年龄、主要女性成员年龄、主要女性成员受教育年限、家庭人口规模与结构、收入水平、储藏条件和膳食知识、家庭类型等变量。