Application of a Three-dimensional Wind Driven Circulation Model to Assess the Locations of New Drinking Water Intakes in Lake Ontario

A 3D transport model is used to perform a comparative analysis of several potential drinking water intakes located along the northwest shore of Lake Ontario between Toronto and Oshawa. The model is specifically used to assess each intake under both long- and short-term transport of a potential pollutant release from the Pickering Nuclear Generating Station and potential and actual pollutant releases from local land sources respectively. A model based on a 500 m grid resolution is calibrated using data collected in the aftermath of the 1992 tritium spill at the Pickering Nuclear Generation Station and subsequently used to simulate long-term transport. A model based on a 100 m grid resolution is verified using drogue studies and used to simulate short-term transport events. Both models are used to assess pollutant levels at each of nine potential intake locations under different wind scenarios and pollutant releases. Field data for the study included water quality and flow measurements from local sewers and rivers, and estimates of pollutant levels from the local waste water treatment plants. This paper describes the model setup for both the long-term and short-term transport models, calibration using field data, long-term transport modeling, short-term transport modeling, and the comprehensive analysis approach used to evaluate the nine potential intake locations proposed. Results indicated that four intakes in particular outperformed other intake locations by maintaining bottom pollutant levels within governmental standards and warning times that exceeded 20 hours.     

Open‐cycle OTEC systems with freshwater product: Effects of noncondensable gases on performance of condenser

An open‐cycle ocean thermal energy conversion (OC‐OTEC) system is one of the energy conversion methods used to generate electricity from ocean thermal energy. For the OC‐OTEC system, steam evaporated from the surface seawater due to flash evaporation drives the turbine. At that time, dissolved gas such as air is introduced into the low‐pressure system (OC‐OTEC system) as the noncondensable gas, which degrades the performance of condensation heat transfer. In this paper, a small‐scale OC‐OTEC experimental unit experimentally investigates the effect of noncondensable gas on the heat transfer performance in a condenser. The experimental results are discussed in comparison with theoretical estimation by the Sparrow–in method. It is shown that the condensation is occupied by heat and mass transfer near a condensation surface and that the condensation efficiency is affected by exhaust quantity of noncondensable gas at a relatively high concentration ratio of condensable gas. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(1): 29–35, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20179     

Effect of Channel Changes in the St. Clair River During the Present Century

Periodic man-made changes in the outlet of Lake Huron through the St. Clair River date back to the middle of the last century. These artificial channel changes have been well documented during the present century. They consist of dredging for commercial gravel removal in the upper river during 1908–25 and uncompensated navigation improvements for the 7.6-m (25-ft) and 8.2-m (27-ft) projects completed in 1933 and 1962, respectively. The total effect of these changes on the levels of Lakes Michigan and Huron (hydraulically one lake) and on the upper St. Clair River profile was determined with dynamic flow models. The ultimate effect of the above dredging was a permanent lowering of the Lake Michigan-Huron levels 0.27 m (0.89 ft), which represents a tremendous loss of freshwater resource [32 km³ (7.7 mi³)].     

Effect of water inlet velocity on thermal stratification in a mantled hot water storage tank

Thermal stratification in a mantled hot water storage tank is analysed numerically for different water inlet velocities. The aim is to obtain higher thermal stratification and supply hot water for usage as long as possible. Twelve different water inlet velocities to the hot water storage tank are considered. The numerical method is validated by comparing its results against experimental and numerical results from the literature. It turned out that the results obtained from the numerical analysis have shown very good agreements with the results from previous works. As a result, the water temperature in the tank increases with the increase of the water inlet velocities to the mantle but this increment is not proportional. After a period of operation of 7.2 h, which corresponds to the average sunshine duration in Turkey, temperature increments of 6.5 and 35 K have been estimated for the hot water inlet velocities of 0.01 and 0.3 m s^?1, respectively, at a radial distance of 0.1 m and a height of 1 m inside the storage tank. Copyright © 2005 John Wiley & Sons, Ltd.     

坑道用水下堵漏剂的研制

坑道水下堵漏剂的研制包括F－1、F－2和F－3型。其中F－1是一种有机堵漏剂，它可以在水中固化；F－2是一种无机防水堵漏剂，施工方便；F－3是速凝型，它可在瞬间固化，能对坑道的涌水口进行堵漏。     

Assessing the relative priority of projects

Where there are a large number of projects competing for a limited pool of resources, projects have to be assigned priorities to determine which should proceed and which should be curtailed. The traditional economic procedures for assessing the relative priority of projects are reviewed, and alternative methods of ranking projects are suggested, with particular emphasis on methods that are inexpensive and easy to use.     

Determination of the total concentration and speciation of Al(III) in tea infusions

The aluminium species in different tea infusions were investigated, by determining their stability constants and concentration. This was done for some particular samples using a simple experimental method based on the sorption of aluminium on the strongly sorbing resin Chelex 100, by a batch procedure. From the thermodynamic information obtained it is possible to calculate the concentration of the different species, and in particular that of the free metal ion, which is very important for evaluating the adsorption of aluminium on biological membranes. It was found that aluminium in the tea infusions here considered is present at high total concentration, approximately 0.1 mM, but mainly linked to strong complexes, for instance with side reaction coefficient higher than 10(5.11) at pH 3.95 in one case (tea 1). This could be the reason for the low toxicity of aluminium in tea. These strong complexes were not dissociated even in the presence of Chelex 100. In this case only a limiting value of the reaction coefficient could be evaluated. The presence of the very strong complexes was found in all the tea sample here considered. In two of the considered samples (one black and one green tea) a part of Al(III) was linked to less strong complexes, for example with a reaction coefficient 10(4.14) (tea 2, pH 4.20). The presence in the considered tea infusions of other substances able to complex aluminium was also detected, by the well known ligand titration procedure, at concentration ranging from 0.65 to 3.37 mM in three tea infusions, and at somewhat higher concentration in the case of the ready drink, which was also considered for comparison.     

利用计算机进行油气资源评价和勘探决策

本文着重介绍了构成《现代勘探决策理论系统》的5个主要计算机模块,即:生油岩热演化处理、求任意曲边形面积、数学模拟预测资源量、勘探经济评价分析及决策、辅助处理等模块。该系统曾在塔里木盆地和准噶尔盆地的油气资源评价和勘探决策中发挥了作用,受到了专家和用户的好评。     

A structure/function study of polyaminoamide dendrimers as silica scale growth inhibitors

Dendrimers have attracted immense attention during the last decade due to their interesting properties both from a basic and an applied research viewpoint. Encapsulation of metal nanoparticles for catalysis, drug delivery and light harvesting are only some applications of dendrimers that are breaking new ground. A novel application of dendrimer technology is described in the present paper that relates to industrial water treatment. Industrial water systems often suffer from undesirable inorganic deposits. These can form either in the bulk or on metallic surfaces, such as heat exchangers or pipelines. Silica (SiO₂) scale formation and deposition is a major problem in high‐silica‐containing cooling waters. Scale prevention rather than removal is highly desired. In this paper, benchtop screening tests on various silica inhibition chemistries are reported, with emphasis on materials with a dendrimeric structure. Specifically, the inhibition properties of commercially available STARBURST^® polyaminoamide (PAMAM) dendrimers generations 0.5, 1, 1.5, 2, and 2.5 are investigated in detail together with other commonly‐used scale inhibitors. Experimental results show that inhibition efficiency largely depends on structural features of PAMAM dendrimers such as generation number and nature of the end groups. PAMAM dendrimers are effective inhibitors of silica scale growth at 40 ppm dosage levels. PAMAM dendrimers also act as silica nucleators, forming SiO₂–PAMAM composites. This occurs because the SiO₂ formed by incomplete inhibition interacts with cationic PAMAM‐1 and ‐2. The general scope of silica formation and inhibition in industrial waters is also discussed. Copyright © 2005 Society of Chemical Industry     

深圳福田河污染治理资源优化配置

根据不同河段的水域功能将污染严重的福田河自上而下划分为三个水污染控制单元，针对每个单元的不同环境目标和污染负荷预测得到相应的污染净化率，依此建立资源优化配置模型，由该模型获得优化决策，以期合理利用环境容量，确定最小净化费用，兴修必要的治理设施，从而保证在经济高速发展的同时，有效地控制福田河的污染问题。