A SIMPLIFIED MODEL FOR PREDICTING DAILY TRANSMISSION LOSSES IN A STREAM CHANNEL1

ABSTRACT: A simplified approach for modeling transmission losses in a stream is presented. A theory relating seepage from a channel with the depth of flow is simplified to a one-parameter relationship. A power relationship is then utilized for the stage-discharge relationship, which is coupled with the seepage relationship. This combined equation is integrated over the channel reach to arrive at a general model for seepage loss through the reach, with one parameter needing calibration. An example is provided showing the development of the relationship and the calibration technique for the parameter. The results are shown, emphasizing the use of the model for simulation of channel transmission losses at low and moderate flow conditions.     

Modelling adsorption of phosphate by soils while the solution concentration decreased with sorption

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城区热电厂灰水系统简易改造设计方案

作为大气污染控制和节能的有效手段，城区热电厂的数量和规模都在增加，针对目前城区热电厂灰水系统普遍存在的问题和制约因素，对系统简易改造的方案设计方法进行了研究。     

碱厂废碱液在湿式烟气脱硫工艺中应用的实验研究

纯碱厂在生产过程中要排放许多废碱液，如果用作烟气脱硫剂，不仅降低了脱硫费用，而且消除报废碱液的主要成分，介绍了旋流板塔式除尘脱硫装置的结构和工作原理，探讨了影响用废碱液除尘脱硫效果的主要因素，并找出了较好的操作条件。实验结果表明：废认在该装置上脱硫和除尘效果均达到国内外同类装置的水平，同量，解决了因为废碱液带来的水污染。除尘脱硫装置结构简单，基建费用和运行费用低，是一项值得推广的技术。     

A comparison of measured and simulated ozone concentrations in the rural areas of the eastern United States during summer 1995

The recent regulatory actions toward a longer-term (i.e., 8-hr) average ozone standard have brought forth the potential for many rural areas in the eastern United States to be in noncompliance. However, since a majority of these rural areas have generally few sources of anthropogenic emissions, the measured ozone levels primarily reflect the effects of the transport of ozone and its precursor pollutants and natural emissions. While photochemical grid models have been applied to urban areas to develop ozone mitigation measures, these efforts have been limited to high ozone episode events only and do not adequately cover rural regions. In this study, we applied a photochemical modeling system, RAMS/UAM-V, to the eastern United States from June 1-August 31, 1995. The purpose of the study is to examine the predictive ability of the modeling system at rural monitoring stations that are part of the Clean Air Status Trends Network (CASTNet) and the Gaseous Pollutant Monitoring Program (GPMP). The results show that the measured daily 1-hr ozone maxima and the seasonal average of the daily 1-hr ozone maxima are in better agreement with the predictions of the modeling system than those for the daily 8-hr ozone maxima. Also, the response of the modeling system in reproducing the measured range of ozone levels over the diurnal cycle is poor, suggesting the need for improvement in the treatment of the physical and chemical processes of the modeling system during the nighttime and morning hours if it is to be used to address the 8-hr ozone standard.     

Breeding biology of Megalops cyprinoides from Visakhapatnam coast

Studies on stages of maturity, gonado-somatic indices and breeding cycle from two different habitats viz., the polluted Harbour Waters and the unpolluted Yerragedda Mouth revealed that M. cyprinoides breeds twice a year i.e., during Jan-Jul and Dec-Jan. Size at first maturity was 18 cm. in females and 19 cm. in males at both the stations. Sex ratio was 1:1 at the polluted station and 1:1.1 at the unpolluted station indicating a slight domination of females.