An abbreviated alternatives assessment process for product designers: a children’s furniture manufacturing case study

Alternatives assessment is becoming increasingly popular to evaluate the potential environmental and human health hazards of materials. A three step process was used to identify and evaluate alternative products for a children's furniture manufacturer. An alternatives assessment framework was developed to analyze alternative mattresses. The framework specifically addresses those environmental and safety attributes applicable to the product and the product components in accordance with the product’s intended use. The result of the assessment allowed the manufacturer to select the most environmentally friendly alternative and eliminate polyvinyl chloride from their product.     

中国地区经济差距及其演化的产业变动因素

20世纪90年代以来中国地区经济差距扩大具有深刻的产业变动原因。以人均GDP为基本指标,通过对基尼系数进行产业分解和对泰尔指数进行地区分解,深刻分析了1990~2004年中国地区经济差距的动态变化、地区构成和产业构成,揭示了中国地区经济差距及其演变的产业结构变动与产业地区集中因素。结果表明,1990年以来中国地区经济差距的决定性因素是第二产业发展水平的地区差距,而非农产业向东部沿海地区的集中又是推动中国地区经济差距扩大的主导性因素。20世纪90年代以来,随着以制造业为主的非农产业向东部沿海地区集中,中西部地区逐渐沦落为以农业与采掘业为主的外围区域,中国的地区经济差距也由此持续扩大。基于此,认为缩小地区差距的关键是推进中西部地区制造业发展,缓解非农产业地区分布的不平衡状况。     

中亚热带马尾松林凋落物分解过程中的微生物与酶活性动态

采用凋落物原位分解法,研究了中亚热带马尾松林中马尾松、槲栎凋落叶单独及混合(自然质量比8∶2)分解过程中的微生物数量与酶活性动态.结果表明:①3类凋落物的年分解常数K的大小为:混合凋落物(0.94)>槲栎凋落物(0.86)>马尾松凋落物(0.67);②3类凋落物真菌数量和微生物数量均在夏季(135 d时)达到最大值,而此时细菌和放线菌数量最低;③3类凋落物纤维素酶活性、酸性磷酸酶活性均与凋落物干重剩余率呈显著正相关(P<0.05),而马尾松与混合型凋落物中的多酚氧化酶活性同凋落物干重剩余率呈极显著负相关(P<0.01);④微生物数量和多酚氧化酶活性均总体表现为槲栎凋落物>混合凋落物>马尾松凋落物,酸性磷酸酶活性多表现为槲栎凋落物最低,与分解常数K排列有一定的差异,说明凋落物分解是微生物和多种酶共同作用的结果.整体研究表明,凋落物质量和季节气候的差异显著影响微生物群落及其调控的生态过程,与纯马尾松凋落叶相比,针阔混合使微生物数量和多酚氧化酶活性显著提高,这可能是导致分解加快的重要原因.     

对硝基苯胺耐盐降解菌S8的筛选及特性研究

从江苏农药厂活性污泥中筛选出1株能以对硝基苯胺为唯一碳源和氮源生长代谢的耐盐降解菌S8.通过对其形态特征、生理生化特性以及16S rDNA序列分析,确定为枯草芽孢杆菌(Bacillus subtilis).研究表明,该菌株具有较强的对硝基苯胺降解能力.当温度31℃和pH 6.0时,S8在72 h内对60 mg·L-1和120 mg·L-1对硝基苯胺的降解率分别为65.6%和55.8%.在高盐条件下,S8仍有较强的降解能力,当盐含量为7%时,对硝基苯胺降解率为49.5%(72 h);当盐含量为10%时,对硝基苯胺降解率为27.4%(72 h).利用LC-MS法分析降解产物时,共发现6种分子量不同的化合物,其中两种为苯酚及对苯二酚.此为首次关于对硝基苯胺耐盐菌株的研究报道,菌株S8可用于含有对硝基苯胺的高盐工业废水的微生物修复.     

基于代谢产物调控的活性污泥沉淀性能控制原理研究

通过对不同沉降性能活性污泥的胞外聚合物(EPS)进行荧光特性分析,探讨了荧光强度峰值、荧光区域积分等参数与污泥沉降性能的关系.研究表明,典型波长下荧光强度峰值与污泥沉降性能之间有很好关联性,据此,建立了微生物典型代谢产物与沉淀性能的调控曲线即活性污泥的安全操作线与微生物代谢状态曲线,确立了活性污泥沉淀性能调控区域即高代谢产物区可获得良好的固液分离效果.研究成果从微生物代谢的角度揭示了絮体结构的调控方法,具有重要的理论意义.     

基于功能仿真的电子产品性能退化分析方法

目的研究基于功能仿真对电子产品长期工作过程中性能退化问题进行分析的方法。方法以DC-DC电源模块为对象,一种方式是直接对电源模块进行加速退化试验,并基于试验数据进行可靠性分析;另一种方式是对电源模块中性能退化关键元器件进行加速退化试验,并将试验数据模型注入到电源模块功能仿真模型中,进行性能退化仿真与可靠性分析,最终对两种分析结果进行对比,验证仿真分析技术的有效性。结果对比显示,加速退化试验分析得到的电源模块平均寿命为281 560 h,仿真分析得到的电源模块平均寿命为357 290 h。结论由于仿真分析方法只考虑了性能退化的关键元器件,结果偏乐观,但是偏差在合理的范围内,证明该方法对于性能退化可靠性分析是有效的,并且应用该方法更便于进行设计改进和迭代分析。     

基于LMDI中国省域氮氧化物减排与实现路径研究

首先基于Kaya恒等式,利用对数平均Divisia指数分解模型(LMDI法)将氮氧化物排放分解为排放因子、能源强度、经济结构、能源结构和经济发展5个因素;其次通过模型得出的脱钩系数运用构建四象限法评价"十二五"期间中国30个省市脱钩空间差异,研究各省市氮氧化物减排表现、分析减排潜力和减排影响因素,为国家"十三五"制定差异化的区域氮氧化物减排目标和寻找多元化的氮氧化物减排途径提供有益参考.研究结果表明:经济增长是促进氮氧化物排放量增加的决定因素,能源强度降低是抑制氮氧化物增排的决定因素,经济结构优化和能源结构调整具有较大促进氮氧化物减排潜力;中国氮氧化物排放与经济增长脱钩空间分异明显,大部分省市经济发展与氮氧化物排放处于脱钩状态,部分省市弱脱钩状态.同时,中国氮氧化物排放与经济增长脱钩系数呈现逐年上升趋势,2010—2015年中国各省市氮氧化物排放脱钩空间分布由较弱、中脱钩为主至中、较强脱钩为主再到较强脱钩为主,呈现区域间"异质化"和区域内"均质化"的趋势.国家氮氧化物后续减排任务应多分解在中脱钩或弱脱钩(减排潜力大)省市,对相邻的省份制定协同减排计划,且主要通过提高能源利用效率、同时优化经济结构和能源消费结构实现其最优减排.     

Sustainable consumption in Brazil: Identification of preliminary requirements to guide product development and the definition of public policies

Sustainable product development is closely related to sustainable consumption. The understanding of consumers' purchase, use and discard behaviours may facilitate the identification of requirements to guide manufacturers in the development of sustainable goods and services. The aim of this paper is to investigate consumers' perception about factors that motivate or discourage the consumption of sustainable products to identify demands and convert them into requirements. South Brazilian green and traditional consumers were asked to complete an exploratory qualitative questionnaire. Their answers were organized and compared to identify differences and similarities between the demands of these two groups. Furthermore, demands were converted into requirements for packages, products, manufactures, stores planning and discard systems. The interpretation of factors that motivate or discourage the purchase of sustainable products given by interviewees led to the creation of a list of possible public policies or programmes, aiming to support sustainable consumption. The results demonstrate the necessity of further quantitative investigation between consumer groups, for validation purposes.     

Value of information in product recovery decisions: a Bayesian approach

There is a widespread recognition of the need for better information sharing and provision to improve the viability of end-of-life (EOL) product recovery operations. The emergence of automated data capture and sharing technologies such as RFID, sensors and networked databases has enhanced the ability to make product information; available to recoverers, which will help them make better decisions regarding the choice of recovery option for EOL products. However, these technologies come with a cost attached to it, and hence the question ‘what is its value?’ is critical. This paper presents a probabilistic approach to model product recovery decisions and extends the concept of Bayes' factor for quantifying the impact of product information on the effectiveness of these decisions. Further, we provide a quantitative examination of the factors that influence the value of product information, this value depends on three factors: (i) penalties for Type I and Type II errors of judgement regarding product quality; (ii) prevalent uncertainty regarding product quality and (iii) the strength of the information to support/contradict the belief. Furthermore, we show that information is not valuable under all circumstances and derive conditions for achieving a positive value of information.     

A user evaluation of biodegradable cutlery

This paper summarizes a study evaluating the acceptance and perceived performance of disposable cutlery made from starch-based biodegradable resins relative to nondegradable polystyrene cutlery. Two hundred forty-three sailors onboard three U.S. Navy vessels ate their lunch using either biodegradable cutlery made with resins manufactured by one of two commercial companies or polystyrene cutlery. The cutlery was rated on several sensory and performance dimensions as well as for overall acceptability. Results indicated that sailors rated both the biodegradable and the polystyrene utensils as easy to hold. There were also no differences in the perceived ease of using each of the spoons. However, compared to the polystyrene utensils, both types of biodegradable utensils were viewed as less sturdy, as having a less attractive color, and as being less acceptable overall. The biodegradable forks and knives were also rated as more difficult to use for piercing and cutting food than the polystyrene ones. In addition, several significant differences emerged between the two types of biodegradable cutlery. The results are discussed in terms of the need for continued consumer testing of products developed from biodegradable polymeric materials.