Cercaricidal activity of some essential oils of plants from Brazil

Extended screening tests on the cercaricidal activity of various plants from northeast Brazil have shown that the extracts of the leaves and fruits ofPiper marginatum,Protium heptaphyllum, andCapsicum annuum show a remarkable effect on the cercaria ofSchistosoma mansoni. In the case of the oils ofPiper marginatum andCapsicum annuum, 90–96% of the cercaria ofSchistosoma mansoni were killed within 15 min. According to the NMR spectra, the active principles of the extracts seem to be water-soluble unsaturated compounds from the oils or their hydrolysis products. Natural substances provide an attractive alternative for preventive actions against schistosomiasis, as the perturbation of the ecological equilibrium of natural waters can be avoided in this manner.     

南海区平台石油的特征荧光光谱分析

通过对南海区平台石油进行普通荧光光谱、同步扫描荧光光谱、导数荧光技术和三维荧光技术扫描,立体地了解各原 油样品荧光光谱特征,为科学鉴别濒发的海上溢油来源提供科学的依据。实验中综合分析了6个平台原油样品,并与标准原油 进行光谱对比,找出了这些样品的光谱数字化特征。     

Process conditions of preparing methanol from cornstalk gas

The low-heat-value cornstalk gas produced in the down-flow fixed bed gasifier was tentatively used for methanol synthesis. The cornstalk gas was purified and the technical procedures such as deoxygenation, desulfurization, catalytic cracking of tar, purification and hydrogenation were studied. The catalytic experiments of methanol synthesis with cornstalk syngas were carried out in a tubular-flow integral and isothermal reactor. The effect of reaction temperature, pressure, catalysttypes, catalyst particle size, syngas flow at entering end and composition of syngas was investigated. The optimum process conditions and yield of methanol from cornstalk syngas were obtained. The experimental results indicated that the proper catalyst of the synthetic reaction was C301 and the optimum catalyst size (φ) was 0.833 mm×0.351 mm. The optimum operating temperature and pressure were found to be 235℃ and 5 Mpa, respectively. The suitable syngas flow 0.9-1.10 mol/h at entering end was selected and the best composition of syngas were CO 10.49%, CO2 8.8%, N2 37.32%, CnHm 0.95% and H2 40.49%. The best methanol yield is 0.418 g/g cornstalk. The study provided the technical support for the industrial test of methanol production from biomass (cornstalk)gas.     

渤海海上原油油指纹库建设

参照国际先进的油指纹分析、溢油鉴别技术以及油指纹库建设方法,建立一套先进的油指纹库建设技术体系,开展了渤海不同区块9个原油油指纹库建设工作。通过本课题的研究,使我国的油指纹库建设技术体系更趋完备,全面提高了溢油鉴别工作的科学性。     

粪便源指纹及其鉴别研究

利用气相色谱-质谱联用仪检测了人和32种动物粪便中以及5个不同排污口表层沉积物中10种粪固醇,以10种粪固醇含量和9个粪固醇比值为指标,分别应用层次聚类分析法对人和32种动物粪便以及5个沉积物的粪便污染来源进行了鉴别,结果表明:草食动物粪便中主要含C29-甾醇,5β-甾醇比5α-甾醇含量多,草食动物粪便的主要指示物是24-乙基粪醇和谷甾醇;肉食动物粪便中主要含C27-甾醇,胆固醇是肉食动物的主要指示物;杂食粪便中粪固醇组成多变;人粪便中主要含粪醇,占总粪固醇的51.5%;应用10种粪固醇含量和9个粪固醇比值以及层次聚类分析法,可以准确地鉴别人和32种动物粪便以及5个沉积物样品的粪便污染来源。     

Reducing greenhouse gas emissions from magnesium die casting

The U.S. magnesium industry uses sulfur hexafluoride (SF₆) as a cover gas to prevent the rapid and hazardous oxidation of molten magnesium. While this gas is considered to be safe and effective in this application, it is one of the most potent and persistent greenhouse gases (GHG) found in the atmosphere. The U.S. Environmental Protection Agency (EPA) launched a collaborative initiative called the SF₆ Emission Reduction Partnership for the Magnesium Industry in 1999 to identify and implement practical technologies for improving the industry's environmental profile. EPA's Partners, joined by the International Magnesium Association (IMA), have voluntarily committed to eliminate the use of SF₆ by 2010. The Partnership and IMA's commitment sent a clear signal to industry suppliers and has precipitated the exploration of alternate cover gases that are just as effective as SF₆ but greatly reduce the process's climate impact. The focus of this study is to assess byproducts, degradation levels, and GHG emission factors for three different fluorinated cover gases (SF₆, AM-cover™, and Novec™ 612) in cold chamber die casting applications. The results of this study are used to describe two approaches that modify current Intergovernmental Panel on Climate Change (IPCC) Good Practice Guidance for estimating cover gas emissions from the magnesium industry.     

Greenhouse gas emissions from rubber industry in Thailand

Rubber production has been taking place in Thailand for many decades. Thailand is currently the world's largest natural rubber producer. We present emissions of greenhouse gases associated with the production of fresh latex, and three primary rubber products, including concentrated latex, block rubber (STR 20), and ribbed smoked sheet (RSS) in Thailand. Besides industrial activities in the rubber mills, the agricultural activities in rubber tree plantation are taken into account. The overall emissions from the production of concentrated latex, STR 20, and RSS amount to 0.54, 0.70, and 0.64 ton CO₂-eq/ton product, respectively. This is for the case that rubber plantations have been located on cultivated lands for more than 60 years, which is current practice in most of Thailand. Emissions are largely associated with energy use and the use of synthetic fertilizers. We also quantify emissions for the case that tropical forests have been converted to rubber plantations relatively recently, which is a recent trend in Thailand. In this case the emissions are much higher because of carbon loss from land conversion: 13, 13, and 21 ton CO₂-eq/ton product for concentrated latex, STR 20, and RSS, respectively. We discuss the implications of our results for strategies to reduce greenhouse gas emissions from rubber production.     

Simulation and life cycle assessment of process design alternatives for biodiesel production from waste vegetable oils

This study uses the process simulator ASPEN Plus^® and Life Cycle Assessment (LCA) to compare three process design alternatives for biodiesel production from waste vegetable oils that are: the conventional alkali-catalyzed process including a free fatty acids (FFAs) pre-treatment, the acid-catalyzed process, and the supercritical methanol process using propane as co-solvent. Results show that the supercritical methanol process using propane as co-solvent is the most environmentally favorable alternative. Its smaller steam consumption in comparison with the other process design alternatives leads to a lower contribution to the potential environmental impacts (PEI’s). The acid-catalyzed process generally shows the highest PEI’s, in particular due to the high energy requirements associated with methanol recovery operations.     

海上船载油品急性生物毒性等级分级方法研究

采用油品水融合组分(WAF)-发光细菌法对WAF制备过程中的搅拌速度、搅拌时间、搅拌温度、静置时间等影响因素进行优化,确定最佳检测条件,并对19种海上船载油品的急性生物毒性进行毒性等级分级研究.研究结果表明,发光细菌法能够检测出不同油品的急性生物毒性,不但具有良好的区分性,而且具有操作便捷、试验成本低和试验周期短等优点...     

Prenatal diagnosis of twin zygosity by DNA ‘fingerprint’ analysis

A twin pregnancy with one hydrocephalic fetus with oligohydramnios is presented. Sonographic evaluation could not exclude monochorionicity. Before considering selective feticide, blood samples from both fetuses were examined for DNA ‘fingerprint’ analysis. The different banding patterns of the blood samples established dizygosity. This procedure is suggested in cases where sonography fails to determine chorionicity.     

Greenhouse gas emissions from nitrogen fertilizer use in China

The use of synthetic nitrogen (N) fertilizers is an important driver of energy use and greenhouse gas (GHG) emissions in China. This paper develops a GHG emission factor for synthetic N fertilizer application in China. Using this emission factor, we estimate the scale of GHG emissions from synthetic nitrogen fertilizer use in Chinese agriculture and explore the potential for GHG emission reductions from efficiency improvements in N fertilizer production and use. The paper concludes with a discussion on costs and financing for a large-scale fertilizer efficiency improvement program in China, and how a GHG mitigation framework might contribute to program design.     

海上溢油化学指纹特性的研究

根据原油所具有的特性,对短期风化前后的大庆和科威特原油中的正构烷烃(n-C10～n-C24,姥鲛烷Pr及植烷Ph)、多环芳烃(PAHs)、石油卟啉以及镍钒比(Ni/V)进行了对比分析。结果显示:大庆和科威特原油中的n-C17/Pr、n-C18/Ph虽然不同,但Pr/Ph基本上无差异,只用诊断比例鉴别有局限性;荧光分析显示油品中大分子的PAHs几乎不受风化的影响,具有稳定特征;两种原油的石油卟啉种类不同,体现出原油产地不同的特征;大庆原油是Ni高V低,而科威特原油是V高Ni低,大庆原油的Ni/V远高于科威特原油。建议把这些特征参数统合在一起构成鉴别原油的化学指纹,以改善现有的油指纹研究的单一性和局限性,更全面地反应原油自身的特性。     

丹东市机动车尾气污染现状与控制措施

调查和研究了9种车型：轿车、出租车、摩托车、中型客车、小型面包车、大公共汽车、轻型货车、中型货车、重型货车的汽油和柴油的NOx，CO、HC、SO2、PM10污染排放量及分别在主干线、次干线、支路、街巷路中每条路段不同时间车流量密度及利用排放因子，求出每条路段机动车污染物排放量。同时分别汇总主干线、次干线、支路、街巷路中9种车型车流量密度及污染物排放量，最后估算出污染物排放总量。     

从人性角度考量环境教育的价值及转向

环境危机产生的根本原因是人性危机。人性危机也就是人对待自然的意识危机。人们将环境问题局限于自然环境本身,只是看到了环境问题的表面症状,而没有看到环境问题产生的内在根源。真正的环境教育不是单纯指向环境的专门教育,而是对整体教育的重新思考。从人性的角度看,环境教育具有智育价值、生态思维价值和美育价值,因此,环境教育的本质应该由物化