蜂窝电话用锂离子电池的环境试验

国家标准GB/T18287-2000《蜂窝电话用锂离子电池总规范》中明确规定了锂离子电池的20℃常温,高温,恒定湿热性能,震动,碰撞,自由跌落等环境试验的具体方法及环境试验后的放电性能测试方法。     

Mechanochemical dechlorination of polyvinyl chloride with calcium sulfates

Polyvinyl chloride (PVC) was milled with hydrated or unhydrated calcium sulfates (CaSO₄·2H₂O or CaSO₄) in air by using a planetary mill to investigate mechanochemical dechlorination behavior. The milling process resulted in size reduction and in the breaking of bonds leading to mechanically induced solid state reaction, forming CaCl₂ and dechlorinated hydrocarbon with C=C double bonds in the product. Washing the milled mixtures with water at room temperature allowed removal of the chloride formed during milling, and more than 95% of the chlorine in PVC was removed from a mixture milled for 4 h. This process could offer a potential route for the handling and disposal of both PVC and gypsum wastes. H₂S gas was generated during milling; more H₂S was released from the unhydrated sample than from the hydrated sample.     

Solid waste characteristics and their relationship to gas production in tropical landfill

Solid waste characteristics and landfill gas emission rate in tropical landfill was investigated in this study. The experiment was conducted at a pilot landfill cell in Thailand where fresh and two-year-old wastes in the cell were characterized at various depths of 1.5, 3, 4.5 and 6 m. Incoming solid wastes to the landfill were mainly composed of plastic and foam (24.05%). Other major components were food wastes (16.8%) and paper (13.3%). The determination of material components in disposed wastes has shown that the major identifiable components in the wastes were plastic and foam which are resistant to biodegradation. The density of solid waste increased along the depth of the landfill from 240 kg m⁻³ at the top to 1,260 kg m⁻³ at the bottom. Reduction of volatile solids content in waste samples along the depth of landfill suggests that biodegradation of solid waste has taken place to a greater extent at the bottom of the landfill. Gas production rates obtained from anaerobic batch experiment were in agreement with field measurements showing that the rates increased along the depth of the landfill cell. They were found in range between 0.05 and 0.89 l kg⁻¹ volatile solids day⁻¹. Average emission rate of methane through the final cover soil layer was estimated as 23.95 g⁻²day⁻¹ and 1.17 g⁻²day⁻¹ during the dry and rainy seasons, respectively.     

Applicability of grid-net detection system for landfill leachate and diesel fuel release in the subsurface

The grid-net system estimating the electrical conductivity changes was evaluated as a potential detection system for the leakage of diesel fuel and landfill leachate. Aspects of electrical conductivity changes were varied upon the type of contaminant. The electrical conductivity in the homogeneous mixtures of soil and landfill leachate linearly increased with the ionic concentration of pore fluid, which became more significant at higher volumetric water contents. However, the electrical conductivity in soil/diesel fuel mixture decreased with diesel fuel content and it was more significant at lower water contents. The electrode spacing should be determined by considering the type of contaminant to enhance the electrode sensitivity especially when two-electrode sensors are to be used. The electrode sensitivity for landfill leachate was constantly maintained regardless of the electrode spacings while that for the diesel fuel significantly increased at smaller electrode spacings. This is possibly due to the fact that the insulating barrier effect of the diesel fuel in non-aqueous phase was less predominant at large electrode spacing because electrical current can form the round-about paths over the volume with relatively small diesel fuel content. The model test results showed that the grid-net detection system can be used to monitor the leakage from waste landfill and underground storage tank sites. However, for a successful application of the detection system in the field, data under various field conditions should be accumulated.     

Dancing Stories: A Community Dance Residency in a Hospice in New Zealand

Canoes forging through cold waters, mountains rising from the sea, a heart beating under a mountain lake, an albatross sailing toward the Antarctic: these were the story-images of Coastal Mappings, a large-scale community project set in and around Dunedin, New Zealand. In the Coastal Mappings performance project, people in the last months of their lives joined cancer survivors, family members and other interested people in explorations of Pakeha myths (by European-settler descendents) and Maori myths (by descendents of the crews of the first canoes, first inhabitants of New Zealand). Together, we created personal landscapes through movement, storytelling, photography and video. In this essay, I discuss some of the opportunities, challenges and experiences of leading a community dance project in an intercultural social environment, and with people whose relationship to their environment is different from mine.     

余热锅炉磨损的数值模拟分析

利用数值模拟方法对余热锅炉进行流场及湍流密度计算结果总结出锅炉主要磨损规律,原因及主要磨损部位,与现场磨损的部位正好吻合,为减少磨损等复杂工程问题提供了理论依据,并就磨损的部位提出了应对措施。     

Measuring Road Traffic Safety Performance: Monitoring Trends in Nonfatal Injury

Traditional indicators used to monitor trends in nonfatal injury are influenced by a range of factors other than the incidence of injury. Indicators based on threat-to-life scales offer a means of addressing this problem. The aim of the research described in this article was to compare trends in the official indicators with trends in selected threat-to-life indicators. We compared indicators based on the New Injury Severity Score and the International Classification of Diseases–based Injury Severity Score with the official New Zealand indicators; namely, (1) reported injuries, (2) reported injuries per 10,000 vehicles, (3) reported injuries per 100,000 people, and (4) number hospitalized (discharges). All the official indicators suggest that there has been a substantive decline in nonfatal Motor Vehicle Traffic Crashes (MVTCs) for the period 1988–2000, but a notable increase in 2001. The latter appear to be artifactual increases due to changes in patterns of data collection and do not reflect any real changes in incidence. Further support for this is provided by the results for the two threat-to-life indicators, which suggest that the decline observed for 1988–98 may have been attributable to a decline in the ascertainment or occurrence of minor injuries since those injuries, which represent a significant threat to life, have not declined to the same degree. Given the prominence of motor vehicle crashes as a cause of unnecessary morbidity, more thought needs to be given to deriving valid indicators for measuring trends in serious nonfatal injury.     

EPA develops process to destroy Kepone

Environmental Management -     

Study on the conversion of waste plastics/petroleum resid mixtures to transportation fuels

Catalytic coprocessing of model and waste plastics with light Arabian crude oil residue was investigated using NiMo/Al₂O₃, ZSM-5, FCC, and hydrocracking catalysts. Reaction systems that were studied included low density polyethylene (LDPE), high density polyethylene (HDPE), polystyrene (PS), and polypropylene (PP). A series of single (plastic/catalyst) and binary (plastic/resid/catalyst) reactions were carried out in a 25-cm³ micro autoclave reactor under different conditions of weight and type of catalyst, duration, pressure, and temperature. The optimum conditions selected for our work were: 1% catalyst by weight of total feedstock weight, 60min reaction time, 8.3Mpa of H₂, and 430°C. The product distribution for the binary system using plastic and petroleum residue provided some encouraging results. High yields of liquid fuels in the boiling range of 100°–480°C and gases were obtained along with a small amount of heavy oils and insoluble material such as gums and coke. In general, this study helps to demonstrate the technical feasibility of upgrading both waste plastics and petroleum resid, as well as an alternative approach to feedstock recycling.     

Landfill mining and waste characterization: a strategy for remediation of contaminated areas

This article describes landfill-mining tests, including excavation, screening, and fraction characterization, carried out in the Msalycke and Gladsax landfills for municipal solid waste (MSW) in Sweden. The excavated waste in these two sites was 17–22 and 23–25 years old, respectively. The main part of Msalycke was unaffected by degradation, and during excavations no substantial amount of biogas was detected. After screening, three size fractions were obtained: <18mm, 18–50mm, and >50mm. Soil amendment and anaerobic digestion with energy extraction are suggested for the first and second fraction, respectively. Incineration with energy recovery is possible with the third fraction after any coarse (inert) material is removed, and construction/demolition waste can easily be recycled provided that it is not contaminated by hazardous material. Excavated waste taken from different depths was also analysed and compared in relation to composition, calorific value, and leachate constituents.