Air Filtration and Radon Decay Product Mitigation

Air cleaning as a means of mitigating the risks arising from exposure to indoor radon progeny has been evaluated in a single-family house in the north eastem US. using an automated, semi-continuous activity-weighted size distribution measurement system. The measurements included radon concentration, condensation nuclei count, and activity-weighted size distribution of radon decay products. Measurements were made in the house with and without an operating air filtration system and with various particle sources common to normal indoor activities operating. Aerosols were generated by running water in a shower, candle burning, cigarette smoking, vacuuming, opening doors, and cooking. Using a room model, the changes in attachment rates, average attachment diameters, and deposition rates of the unattached fraction with and without the air cleaning system were calculated. In the presence of active aerosol sources, the air filtration unit typically reduced the concentration of particles within the hour following the end of particle generation. After candle burning, cigarette smoking, and vacuuming in the bedroom, the reductions of PAEC by air filtration are about 60% with the air filtration system operating in the bedroom. During cooking in the kitchen, the reductions of PAEC in the bedroom with the air filtration system were about 40%. However, for all cases the dose reductions were smaller than the particle and PAEC reductions. For those particles that were generated within the bedroom, there was a 20% to 50% reduction in dose. In the case of cooking where the door was open and particles infiltrated from the rest of the house, the dose reduction was only 5% on average and appears to be insignificant. Thus, the dose reductions were h e r than the reductions in activity concentration, but there were no cases where the estimated dose actually increased.     

An investigation into the occurrence of sewage fungus in rivers containing papermill effluents—IV. Growth in experimental channels dosed with effluents and pure compounds

Wastewaters from the manufacture of pulp and paper have given rise to problems of excessive microbial growth in rivers over a number of years. This paper is the first in a series of four articles describing research undertaken by PIRA at four U.K. paper/board mills (one integrated with pulp production) over the period 1978–1980. This first paper briefly reviews the published literature on sewage fungus growth from pulp and paper mill discharges up to 1978, but mainly describes previously unpublished work undertaken by PIRA over the period 1965–1975. This introductory paper thus provides a state-of-the-art review of methods to control sewage fungus growth from pulp and paper mill effluents prior to commencement of the research described in the following three articles.     

New chemical structural features of coal. The structure of coal products

The object of this paper is to demonstrate the usefulness of the transalkylation reaction for determining chemical structural features of products derived from coal. For example, the method is applied to derivatized coals, coals modified by thermolysis, and materials physically or chemically separated from coals. Data are presented for the pyridine soluble and insoluble parts of two coals, an O-methylated coal, a Birch reduced coal, a solvent refined coal, and a coke. Similarities and differences in chemical make-up of these materials are discussed.     

优化原料结构构 提高废纸利用水平——谈浙江省废纸利用的情况和意见

介绍了浙江省利用废纸造纸的情况,提出改进废纸利用的意见。     

智能组卷系统试题库结构的研究

在分析了传统的组卷系统的组卷算法及相应的试题库结构的基础上，基于遗传算法提出了一种新的试题库结构，并给定具体结构的确定方法。实践表明，这种结构下的试题库很好地配合遗传算法实现了智能组卷，并且系统效率更高，冗余度更小。     

加油站油品常见质量事故分析

分析了中油站产生一些油品质量事故的情况和成因。指出加油站油品的质量事故主要是管理不善，要杜绝加油站油品质量事故，必须坚持执行《中国石油化工集团销售企业油品质管理办法》。     

Process optimisation in sunflower oil extraction by supercritical CO2

A continuous process for the extraction of sunflower oil using supercritical CO₂, featuring multiple extractors, one oil separator and three cascaded CO₂ recovery vessels operating at different pressures, was devised and studied. For every single equipment of the plant making up the process a mathematical model was built. Experimental tests—consisting in measurements of oil solubility in supercritical CO₂—were carried out in a laboratory-scale apparatus to characterise the behaviour of sunflower oil in the separation from the supercritical fluid. The mathematical model of the whole process was coded in the commercial gPROMS process modelling environment where both its simulation and optimisation—this latter assuming the overall oil production cost as the objective function—were carried out. The process- and economics-related results are discussed and compared with those obtained with traditional and cold-pressing extraction.     

上市公司2001年业绩及前景

介绍了新闻纸、文化用纸有包装用纸上市公司2001年的主要业绩并对其发展前景作了分析。     

CP-3助剂在嘴棒成型纸中的应用

介绍CP - 3助剂的特性、用法以及在嘴棒纸中的作用。     

对数正态概率纸的自动生成和分布参数的自动提取

采用对数正态概率纸可以直观地判断一组数据是否服从对数正态分布，而且还可以得到对数正态分布参数，即对数均值和对数标准差。介绍对数正态概率纸自动生成和分布参数自动提取的方法以及据此开发的软件。与手工使用概率纸的常规方法相比，采用所开发的软件不但使用简单、方便，而且能提高计算结果的精度。