On the thermal rupture of 1.9 m propane pressure vessels with defects in their thermal protection system

This paper describes the results from a series of fire tests that were carried out to measure the effect of defects in thermal protection systems on fire engulfed propane pressure vessels.

In North America thermal protection is used to protect dangerous goods rail tank-cars from accidental fire impingement. They are designed so that a tank-car will not rupture for 100 min in a defined engulfing fire, or 30 min in a defined torching fire. One common system includes a 13 mm blanket of high-temperature ceramic fibre thermal insulation covered with a 3 mm steel jacket. Recent inspections have shown that some tanks have significant defects in these thermal protection systems. This work was done to establish what levels of defect are acceptable from a safety standpoint.

The tests were conducted using 1890 l (500 US gallon) ASME code propane pressure vessels (commonly called tanks in the propane industry). The defects tested covered 8% and 15% of the tank surface. The tanks were 25% engulfed in a fire that simulated a hydrocarbon pool fire with an effective blackbody temperature of 870 °C.

The fire testing showed that even relatively small defects can result in tank rupture if the defect area is engulfed in a severe fire, and the defect area is not wetted by liquid from the inside. A wall failure prediction technique based on uniaxial high-temperature stress rupture test data has been developed and agrees well with the observed failure times.     

Current status and research on E-waste issues in Asia

Rapid economic growth in Asia and the increasing transboundary movement of secondary resources will increasingly require both 3R endeavors (reduce, reuse, recycle) in each country and appropriate control of international material cycles. Recently, managing electrical and electronic waste (E-waste) has become an important target for domestic and international material cycles from the viewpoints of environmental preservation and resource utilization efficiency. To understand the current status of E-waste issues in the context of international material cycles and to discuss the future tasks related to achieving 3R in the region, we organized the National Institute for Environmental Studies (NIES) E-waste Workshop in December 2004. This article reviews past studies on E-waste and briefly describes the topics presented and discussions held at the workshop. The topics at the workshop included E-waste generation, recycling systems, international trade, and environmental impacts. In addition, we discussed various issues such as terminology, current environmental concerns, and possible solutions. Transboundary shipments of E-waste should be conducted taking into consideration the concept of sustainable development. The direction of future research and possible collaborations are also discussed.     

臭氧-生物活性炭深度处理黄浦江水源水中试研究

以黄浦江水源水厂的滤后水为试验对象，进行饮用水O3-BAC深度处理工艺影响因素的中试研完。针对进水水质的试验结果表明，最优臭氧投加量为3mg／L左右，空床停留时间为15min左右。试验结果可为工程设计提供有益的参考。     

安徽省土地资源人口承载力的动态研究

基于《安徽省统计年鉴》，对全省近10年的土地资源、粮食生产及人口增长状况进行了分析。在此基础上，运用相关数学模型对2005-2020年全省人口数量、耕地面积和粮食单产分别进行了预测。为了提高预测精确度，取各种预测方法的平均值。根据安徽省情将其划分为温饱型、小康型和富裕型三档生活标准，分别探讨了预测期内安徽省土地承载力状况，提出了相应的发展对策和建议，为全省发展粮食生产提供科学依据。     

溜砂坡的成灾机理与防治对策

溜砂坡足我国西部山区公路的主要地质灾害之一。由于对溜砂坡的形成发展机理认识不足，目前采用的治理措施不能很好地解决溜砂灾害，有些工程措施反而会加大灾害程度。通过对川藏公路沿线溜砂坡的调查研究，阐述了溜砂坡的最基本特性是其生长性，分析了溜砂坡的成灾机理和危害性特点，有针对性地提出了符合西部地区经济条件的溜砂坡防治措施。     

Calculating overpressure from BLEVE explosions

Although a certain number of authors have analyzed the prediction of boiling liquid expanding vapour explosion (BLEVE) and fireball effects, only very few of them have proposed methodologies for predicting the overpressure from such explosions. In this paper, the methods previously published are discussed and shown to introduce a significant overestimation due to the erroneous thermodynamic assumptions—ideal gas behaviour and isentropic vapour expansion—on which they are based (in fact, they give the maximum value of overpressure which can be caused by a BLEVE). A new approach is proposed, based on the—more realistic—assumption of an adiabatic and irreversible expansion process; the real properties of the substance involved in the explosion are used. The two methods are compared through the application to a given case.     

Application of tracer ratio and inverse dispersion methods with boat-based plume measurements to estimate ammonia emissions from seabird colonies

Ammonia emissions from two contrasting seabird colonies in Scotland were measured, based on the determination of atmospheric concentrations downwind of the colonies. Atmospheric concentrations of ammonia (NH₃) across the downwind plume were compared with the inverse application of a Gaussian dispersion model (ID) to calculate the modelled NH₃ emission that would generate the measured cross-wind-integrated plume concentration. In parallel, a tracer gas (sulphur hexafluoride, SF₆) was released from the colonies with air samples taken to allow determination of SF₆ concentrations. On the basis of the known emission rate of SF₆, the magnitude of ammonia emissions was estimated by the cross-wind-integrated tracer ratio (TR) of NH₃/SF₆ concentrations. Coupled with data on annual bird attendance, the measurements indicate annual emissions from the Isle of May and the Bass Rock of 18 and 132 tonnes NH₃-N year^–1, respectively. The measured NH₃ emissions were compared with estimates of seabird nitrogen excretion to estimate the proportion of excreted N that is volatilised as NH₃ (F_Nr). The emission estimates of the two methods compared favourably, giving 4 and 6 kg NH₃-N h^–1 (F_Nr = 15%) for the Isle of May for the ID and TR methods, respectively, and 21 and 25 kg NH₃-N h^–1 (F_Nr = 50%) for the Bass Rock for the ID and TR methods, respectively. The results provide the first measurement-based estimates to allow regional up scaling of ammonia emissions from seabirds.     

Modelling nitrogen fluxes at the landscape scale

The distribution and impacts of different nitrogen pollutants are inextricably linked. To understand the problem fully, the interactions between the different pollutants need to be taken into account. This is particularly important when it comes to abatement techniques, since measures to reduce emissions of one nitrogen pollutant can often lead to an increase in another. This project represents a step towards greater understanding of these issues by linking together new and existing nitrogen flux models into a larger framework. The modelling framework has been constructed and some of the nitrogen flows between fields, farms and the atmosphere have been modelled for a UK study area for typical farm management scenarios.     

Rapid amino acid cycling in arctic and antarctic soils

Amino acids constitute one of the largest inputs of organic nitrogen (N) to most polar soils and have been hypothesized to be important in regulating vegetational succession and productivity in Arctic ecosystems. Our understanding of amino acid cycling in these soils, however, is poor. The aim of this study was to investigate the size and rate of turnover of the amino acid pool in a range of Arctic and Antarctic soils. Our results indicate that in polar soils with either high or low ornithogenic inputs the amino acid pool is small in comparison to the inorganic N pool (NO^–₃ and NH⁺₄). The free amino acid pool constituted only a small proportion of the total dissolved organic nitrogen (DON) pool in these soils. Here we show that these low concentrations may be due to rapid use by the soil microbial community in both Arctic and Antarctic soils. The turnover of the amino acid pool in soil was extremely rapid, with a half-life ranging from 2 to 24 h, indicating that this N pool can be turned over many hundred times each summer when polar soils are frequently unfrozen. The implications of amino acids in N cycling and plant and microbial nutrition are discussed.