Organic micro-pollutant removal in liquid-phase using carbonized silk cotton hull

Phenolic compounds constitute one of the major pollutants in the modern world. Although many physical and chemical treatment technologies for their removal exist, most of them are economically not feasible. The present study was aimed at using silk cotton hull, a potent agricultural waste as an adsobent for removal of 2,4-dichlorophenol (2,4-DCP), which was used as a model phenolic compound. The process parameters were investigated and optimized conditions were determined. The equilibrium time was found to ...     

Road safety effects of roundabouts in Flanders

INTRODUCTION: This paper analyzes the effect on road safety of 95 roundabouts that were built in Flanders between 1994 and 1999. RESULTS: The study shows that the effect on the number and severity of road accidents adjusted for the trend and regression to the mean is significant, but varies considerably in accordance with the speed limit regime on the intersection. Roundabouts are most effective on intersections of a main road with a high speed limit (90 km/h) and an adjacent road with a lower speed limit (50 or 70 km/h). The empirical analysis reveals a reduction of 34% (varying between 15% and 59%) for the total number of injury accidents, 30% (7%-45%) for light injury accidents, and 38% (27%-72%) for serious injury accidents. This study also takes a closer look at the impact of different post-implementation periods using accident data of 1-, 3-, or 6-years after the construction of a roundabout on the calculated effectiveness results and warns for a severe underestimation when a one-year period is used. IMPACT ON INDUSTRY: An effective traffic safety policy based on scientific results thus requires some patience from the policy-makers.     

光催化降解亚甲基蓝的影响因素及动力学研究

进行了亚甲基蓝在硫化镉上的暗吸附反应,并作Langmuir拟合和Freundlich拟合计算其吸附速率常数。通过实验证明硫化镉光催化降解亚甲基蓝符合一级动力学反应。在低光强下,反应速率常数随着光强的增大而增大,两者之间存在显著的线性关系。改变光催化反应温度,计算表观活化能Ea为19.13kJ/mol,证明温度对反应影响较小。     

微电解杀藻研究

研究表明，用杀藻器进行微电解杀灭湖泊中藻类的效果显著，当进水流量１ｍ＾３／ｈ，电流密度为８．９－１１．８ｍＡ／ｃｍ６２以及当进水流量０．５ｍ＾３／ｈ，电流密度在５．９－８．９ｍＡ＝ｃｍ＾２时，杀藻效果均极好，明显破坏藻类细胞中叶绿体的结构，使藻类的光合使用明显减弱。     

A field experimental study of lignin sand stabilizing material (LSSM) extracted from spent-liquor of straw pulping paper mills

A new technique was introduced for sand stabilization and re-vegetation by use of lignin sand stabilizing material(LSSM). LSSM is a reconstructed organic compound with lignin as the most dominant component from the extracts of black-liquor issued by straw pulp paper mills. Unlike the polyvinyl acetate or foamed asphalt commonly used for dune stabilization, the new material is plant-friendly and can be used with virescence actions simultaneously. The field experimental study was conducted since 2001 in China‘s Northwest Ningxia Hui Autonomous Region and has been proved that LSSM is effective in stabilizing the fugitive dunes, making the arenaceous plants survive and the bare dune vegetative. The advisable solution concentration is 2% and the optimal field spraying quantity is 2.5L/m^2 The soil nutrients of the stabilized and greened dune, such as organic matter, available phosphorous and total nitrogen are all increased compared with the control treatment, which is certainly helpful to the growth of arenaceous plants. The technique is worthwhile to be popularized because it is provided not only a new method for desertification control but also an outlet for cleaning contaminants issued from the straw paper mills.     

环境水面苯乙烯挥发特性的实验研究

阐述了苯乙烯的各类特性，对环境的危害以及苯乙烯的挥发机理。对环境水面上的苯乙烯在不同气象条件（风速，水面温度）下的挥发速率进行了实验研究。分析了影响苯乙烯挥发特性的诸因素。得到了苯乙烯挥发的实验关联式。结果表明，环境水面上的风速与水面温度对苯乙烯的挥发速率均存在影响，风速对苯乙烯挥发速率的影响要大于水温。     

CTL-12型化学需氧量测定仪应用研究

采用CTL-12型化学需氧量测定仪测定CODCr,并与传统的重铬酸钾法比较。实验结果表明,该仪器适用于多种废水、不同浓度CODCr的测定,具有准确、简便、快速等特点。     

关于宁夏环境监测工作存在问题及其对策的研究

通过认真、细致的分析环境监测工作存在的主要问题，提出了宁夏监测工作创新发展的思想与建议。     

Thermal performance of ice-making machine with a multi-channel evaporator

An experimental investigation is presented in this paper on the vapor compression refrigeration cycle used in an ice-making machine with a multi-channel evaporator. To study the operation performance of the refrigeration system in the ice-making machine, the fluid temperature distribution in multi-channel evaporating coils are tested and the dynamic variations in each cooling loop are investigated during the ice-generating phase. The results show that the external cooling loops have the largest temperature fluctuations caused by the large initial refrigerant injecting mass flow and the external environmental disturbances. For the inner cooling loops, the related temperature profiles of different test points have relative stable variations. To reduce the temperature fluctuations of the outside loops, it is suggested to reduce the initial refrigerant mass flow and adjust the initial opening of the thermal expansion valve. Moreover, it is the normal phenomenon for the slight temperature variations for the temperature curves of different test points, caused by the adjustment of thermal expansion valve. During the ice-making process, both the sensible heat removal phase and latent heat removal phase are experienced successively. To remove the sensible heat of water, the refrigerant system is operating in high efficiency with test points having a rapid linear temperature reduction. While for eliminating the latent heat of ice, it requires much more power supply, the relating test points have a temperature decrease with fluctuations. To improve the operation performance of ice machine, some suggestions and improvements are proposed.     

An empirical bayes safety evaluation of tram/streetcar signal and lane priority measures in Melbourne

Objective: Streetcars/tram systems are growing worldwide, and many are given priority to increase speed and reliability performance in mixed traffic conditions. Research related to the road safety impact of tram priority is limited. This study explores the road safety impacts of tram priority measures including lane and intersection/signal priority measures.

Method: A before–after crash study was conducted using the empirical Bayes (EB) method to provide more accurate crash impact estimates by accounting for wider crash trends and regression to the mean effects. Before–after crash data for 29 intersections with tram signal priority and 23 arterials with tram lane priority in Melbourne, Australia, were analyzed to evaluate the road safety impact of tram priority.

Results: The EB before–after analysis results indicated a statistically significant adjusted crash reduction rate of 16.4% after implementation of tram priority measures. Signal priority measures were found to reduce crashes by 13.9% and lane priority by 19.4%. A disaggregate level simple before–after analysis indicated reductions in total and serious crashes as well as vehicle-, pedestrian-, and motorcycle-involved crashes. In addition, reductions in on-path crashes, pedestrian-involved crashes, and collisions among vehicles moving in the same and opposite directions and all other specific crash types were found after tram priority implementation.

Conclusions: Results suggest that streetcar/tram priority measures result in safety benefits for all road users, including vehicles, pedestrians, and cyclists. Policy implications and areas for future research are discussed.