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51.
Growing interest in green products has provided fresh impetus to the research in the field of renewable materials. Plant fibers are not only renewable but also light in weight and low in cost. Polymer composites manufactured using them find applications in diverse fields such as automobiles, housing, and furniture. However, their hydrophilic nature and inadequate adhesion with matrix limits their use in high performance applications. In this study, a novel method for improving adhesion characteristics of natural fibers has been developed. This method is carried out by treating hemp fibers with a fungus: Ophiostoma ulmi, obtained from elm tree infected with Dutch elm disease. Treated fibers showed improved acid–base characteristics and resistance to moisture. Improved acid–base interactions between fiber and resin are expected to improve the interfacial adhesion, whereas improved moisture resistance would benefit the durability of the composites. Finally, composites were prepared using untreated/treated fibers and unsaturated polyester resin. Composites with treated fibers showed slightly better mechanical properties, which is most probably due to improved interfacial adhesion.  相似文献   
52.
Towards a grand deal on subsidies and climate change   总被引:3,自引:0,他引:3  
Recent studies have identified public subsidies as a principal cause of unsustainable development. Worldwide, governments are spending up to $U950 billion a year on subsidies. Many of these public subsidies fail to serve their purpose and in fact, often turn out as policy failures as they further distort trade and cause environmental harm. The energy sector is among the most subsidized sectors in the world, receiving over $U240 billion per annum of public subsidies. This article highlights current energy subsidies and their implications. The article examines: (i) the global size and distribution of energy subsidies in industrialized and developing countries; (ii) the impact of these subsidies on the economy, equity and the environment and their role as barriers for sustainable development; (iii) the political economy behind public subsidies and the various political and institutional barriers and lock-in mechanisms that cause subsidies to become entrenched in economic and public structures; and (iv) proposals for effective subsidy reform in energy policies, suggesting a global strategy to eliminate energy subsidies. OECD governments are in a position to take the lead, and the UN Framework Convention on Climate Change presents an excellent opportunity of striking a political grand deal and linking the reform of energy subsidies to a meaningful participation of developing countries to the Kyoto Protocol. Moreover, if sinks are to be included in the clean development mechanism (CDM), it is crucial to include the removal of forestry subsidies in the grand deal.  相似文献   
53.
Progress in formulating and implementing effective adaptation policies is often hampered by a wide variety of barriers that are well documented in the literature. Among the barriers are lack of awareness, certainty, resources and political commitment. Since these and other barriers can be overcome (e.g., by raising awareness, closing knowledge gaps, and increasing resources), numerous decision‐support frameworks (mainly written guidelines) have been developed for this purpose. The present paper takes stock of both the barriers in adaptation policymaking, as documented in the literature, and the guidelines that aim to facilitate public policies on climate change adaptation. It then compares to what degree selected adaptation guidelines serve as knowledge‐brokerage tools that provide guidance on how to overcome the barriers addressed in the scientific literature. The comparison shows that adaptation guidelines address barriers of adaptation policymaking neither comprehensively nor systematically. Since most adaptation guidelines focus on (subjective) experiences with good practices than on empirical research findings, we conclude that they represent a missed opportunity of scientific knowledge‐brokerage in climate change adaptation.  相似文献   
54.
能效对标管理是改善企业经营管理、提高企业竞争力最有效的管理工具之一。介绍了能效对标管理在国内外的应用、存在的障碍及相关对策建议。  相似文献   
55.
以三种结构的高速铁路声屏障为研究对象,测量了高速列车通过有声、无声屏障两种状态下8个测点的声压值,并计算各测点等效连续A计权声压和声屏障的隔声量,结合GB3096-2008中规定的环境噪声限值进行声屏障结构对高速铁路周边居民的声环境影响评价。试验分析结果表明:声屏障不同程度改善了居民的声环境;由于试验所用的三种结构的声屏障隔声量离一般设计要求(20~25dB(A))相差太远,使得高速铁路周边环境噪声高于国家标准规定限值;声屏障结构改进应着力提高中低频噪声的隔声量。  相似文献   
56.
通过对绍兴市印染业现状减排的分析,分别从行业布局、工艺设备、企业管理和废水治理4个方面,识别未来印染行业减排所面临的障碍,提出“十二五”时期绍兴市印染行业减排策略:加快产业聚集,优化产业布局;强化环境准入,加强源头控制;加强企业技术进步,促进产业升级;完善相关标准,提高污染防治水平;实施清洁生产,提高企业管理水平;严格监管,加强环保执法。  相似文献   
57.
采用"复合过滤法"处理生物质焦油废水,通过分析生物质焦油废水水质特点,筛选出滤料的种类、确定滤料的配置比,并经实验对比分析。结果表明,经复合过滤法处理后的焦油废水COD、焦油、SS的去除率分别达到54%、60%、68%。该技术工艺简单,运行成本低,管理方便,可广泛用于农村生物质气化站的焦油废水处理。  相似文献   
58.
Low-concentration gas transported in pipelines may lead to explosion accidents because gas with a concentration of less than 30% is prone to explode. To reduce the incidence of gas explosions, water sealing of fire barriers is implemented, and explosion venting devices are installed along the pipeline. To investigate their suppression effect on low-concentration gas explosion, experiments using methane–air premixed gas under different conditions were implemented on a DN500 pipeline test system. The effects of three types of explosion venting forms (rupture disc, asbestos board, and plastic film) on explosion overpressure and flame were compared and analysed. Results show that the rupture disc, asbestos board, and plastic film can achieve adequate explosion venting, causing the peak decay rates of explosion overpressure to reach 82.37%, 81.72%, and 90.79%, respectively. The foregoing indicates that the greater the static activation pressure of the explosion venting form, the higher the peak explosion overpressure at each measurement point. Moreover, the shorter the explosion flame duration, the greater the flame propagation velocity. The research results provide an essential theoretical foundation for the effective suppression of gas explosion accidents in the process of low-concentration gas transportation.  相似文献   
59.
This study reports an overview of the economic, social and environmental performance of the main South American countries (SAC) as measured by the Sustainable Society Index. This is a well-known composite indicator, composed of 21 indicators, grouped in seven categories, covering environmental, social and economic wellbeing dimensions. Thirteen European countries recently incorporated into the European Union (NEUC) are considered as a reference. The study covers the period 2006–2016. The South American Region features significant natural resources and plays an important role in the global economy. However, there is concern about the long-term sustainability of social and economic development, given the high rate of economic growth based on the production of low added-value primary products. Sustainable development requires reasonable balance between economic, social and environmental performance, as well as a sustained and balanced increase in performance associated with those fundamental dimensions. Moreover, it is important to agree on minimum performance levels for all performance indicators, taking into account particular social, economic and environmental realities. SAC feature a clear imbalance in some categories affecting the economic, social and environmental wellbeing dimensions, showing either stagnation or significant decrease in recent years. It can be concluded that in the light of findings reported here, South American countries are far from being on the pathway towards sustainable development.  相似文献   
60.
Biofilm is an effective simultaneous denitrification and in situ sludge reduction system, and the characteristics of different biofilm carrier have important implications for biofilm growth and in situ sludge reduction. In this study, the performance and mechanism of in situ sludge reduction were compared between FSC-SBBR and SC-SBBR with constructed by composite floating spherical carriers (FSC) and multi-faceted polyethylene suspension carriers (SC), respectively. The variation of EPS concentration indicated that the biofilm formation of FSC was faster than SC. Compared with SCSBBR, the FSC-SBBR yielded 0.16 g MLSS/g COD, almost 27.27% less sludge. The average removal rates of COD and NH4+-N were 93.39% and 96.66%, respectively, which were 5.21% and 1.43% higher than the average removal rate of SC-SBBR. Investigation of the mechanisms of sludge reduction revealed that, energy uncoupling metabolism and sludge decay were the main factors for sludge reduction inducing 43.13% and 49.65% less sludge, respectively, in FSC-SBBR. EEM fluorescence spectroscopy and SUVA analysis showed that the hydrolytic capacity of biofilm attached in FSC was stronger than those of SC, and the hydrolysis of EPS released more DOM contributed to lysis-cryptic growth metabolism. In additional, Bacteroidetes and Mizugakiibacter associated with sludge reduction were the dominant phylum and genus in FCS-SBBR. Thus, the effect of simultaneous in situ sludge reduction and pollutant removal in FSC-SBBR was better.
  相似文献   
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