Scaling is a major problem in cooling water circuits as it reduces water flow and therefore affects the efficiency of the circuit. The natural organic matter has been suggested in earlier studies to limit the formation of calcium carbonate scaling by complexing the calcium ion. It was therefore the aim of this study to characterize the natural organic matter in the cooling water circuits at Lethabo power station (Vereeniging) and to investigate its potential to complex with calcium. The cooling water and raw water samples were comprehensively analyzed for major metal ions, anions and dissolved organic carbon using AAS, ICP-OES, IC and TOC analyzer and the results entered into MINTEQA2 speciation program to determine the precipitation potential of aragonite and calcite in the water samples. The natural organic matter from the cooling water and raw water were isolated initially through the cross-flow ultrafiltration using a polysulfone membrane with a molecular weight cut-off of 45 kDa. The collected isolates were characterized by ultraviolet-visible spectrophotometer, Fourier transform-infrared spectroscopy and (carbon, hydrogen and nitrogen) elemental analysis. The natural organic matter was also fractionated on ultrafiltration stirred cells using membranes with molecular weight cut-off of 1 kDa, 10 kDa and 100 kDa and then characterized using high performance size-exclusion chromatography. The isolated fractions were also titrated with sodium hydroxide and with calcium chloride to determine the amounts of carboxylic and phenolic groups available for complexation and the extent of the complexation of the fractions with calcium respectively. The speciation results from MINTEQA2 indicated that the raw water had a potential to be corrosive and the cooling water had a potential to scale. Higher concentrations of the natural organic matter were detected in the permeate from the cross-flow ultrafiltration process which suggested that it had predominantly a low molecular weight fraction. This low molecular weight fraction was further confirmed by the results from the high performance size-exclusion chromatography analysis of the fractions obtained from the fractionation process using ultrafiltration stirred cells. The specific ultraviolet absorbance and ratios of 465 to 656 nm absorbances results indicated that the organic compounds were mostly aliphatic in character. Titration of the concentrated organic isolates with sodium hydroxide solution revealed that the fractions had a high content of titratable acidic groups and titrating with calcium chloride showed that there is considerable complexation with calcium to affect calcium carbonate precipitation. / Dr. M. Shumane

M.Phil. / The aim of this study is to achieve a greater output by scrutinizing the present way of coordinating the efforts Qf Steam Industries in South Africa to achieve a sustainable industrial development by using energy source efficiently and effectively. Furthermore into the study we look at obstacles that prevents and those that leads to maximum utilization of energy management measures, and also highlights the effects of implementing cheap available energy source in South Africa...

No description available.

This dissertation represents an effort to advance interdisciplinary research in issues relevant for energy and environmental policy, combining economics with applied engineering and ecology. It includes work that is informed by theoretical and empirical studies, and is conceptually centered in the notion that competitive markets lead to inefficient combinations of risk and yield. In the first two chapters of the dissertation, I study this in the context of wind energy capacity investments, where profit-maximizing developers choose the location and timing of the construction of wind farms. The final chapter of the dissertation is an empirical study on the effects of intensive aquaculture on water pollution.

Bibliography: pages 168-174. / The Emergency Electric Power Supply Systems at Pressurized Water Reactor Nuclear Power Plants are reviewed, problem areas are identified, and recommendations are made for existing and future Nuclear Power Plants. A simplified introduction to a typical Pressurized Water Nuclear Reactor is given and the problems associated with the commercial use of nuclear power are discussed. An overview of the Nuclear industry's solutions is presented and covers the Reliability of equipment and the American Regulatory requirements. The alternating and direct current power supply systems are examined in terms of plant operational state and equipment type (Diesel generators, Grid network, Lead-acid batteries, Battery chargers, Inverters, and Power Distribution networks). The trends in the design of Emergency Electric Power supply systems at Nuclear Power Plants are presented. The loss of all alternating current power, known as Station Blackout, is discussed and the American and European response to this. problem is presented. Problems experienced in the direct current systems are discussed and solutions are presented. The experience at Koeberg Nuclear Power station with Lead-acid batteries is included in the discussion. The thesis concludes with recommendations for designers and operators of the Electric Power Supply Systems at Nuclear Power Stations.

The purpose of this essay is to perform an empirical test of the hypothesis that distance to an operative nuclear power plant will affect property pricing. The focus is on three counties in Sweden that have nuclear power plants. The hedonic pricing method is employed to fulfill the purpose. This involves an econometric cross-section analysis where the price of a property is assumed to be influenced by various housing characteristics, a distance variable, and time specific effects. The data were provided by Svensk Mäklarstatistik and were collected from the period 2005-2021. The material included information regarding property prices and property characteristics. The results suggest that there is a positive statistical relationship between the level of property prices and the distance to an operative nuclear power plant. However, we only find this relationship for Varberg and Oskarshamn. This result is in some contrast to the findings of a few previous studies. / Syftet med denna uppsats är att genomföra ett empiriskt test av hypotesen att avståndet till ett operativt kärnkraftverk påverkar nivån på fastighetspriserna i de tre kommuner i Sverige som har etablerade kärnkraftverk. Detta syfte besvaras genom att tillämpa den så kallade fastighetsvärdemetoden. En ekonometrisk modell specificeras där den beroende variabeln, priset på en fastighet, förklaras av olika karakteristik hos fastigheten samt bostaden, avståndet till närmaste operativa kärnkraftverk, och tidsspecifika effekter. Datamaterialet samlades in från Svensk Mäklarstatistik och innehöll data från tidsperioden 2005 till 2021. Datamaterialet bestod av fastighetspriser samt fastigheternas karaktärsdrag. Resultaten visar att det finns ett positivt statistiskt samband mellan nivån på fastighetspriserna och avståndet till ett operativt kärnkraftverk. Fastighetspriserna tenderar, allt annat lika, att vara lägre på platser som ligger nära kärnkraftverket men detta resultat erhålls endast för Varberg och Oskarshamn. Uppsatsens resultat skiljer sig åt från ett flertal tidigare studier.

Thesis (Nucl. E.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographies and index. / by Claudio Daniel Antonini. / Nucl.E.

No description available.

No description available.

It is the purpose of this study to show how successfully electric power systems were operated by smaller units of government. One of the most notable power plants is operated in Denton, Texas. In this study, the history of this system will be presented, followed by an analysis of its social and economic significance.