New emission legislation regarding air pollution control, as instructed by the Department of Environmental Affairs (DEA) to Eskom Generation Power Stations, implies a particulate emission limit of 100 mg/Nm3 for all existing power stations by 2015 and 50 mg/Nm3 for all new and existing power stations by the year 2020. Some of Eskom’s power stations which are equipped with Electrostatic Precipitators (ESP’s) were not designed for this stringent legislation. It is also experienced that ESP’s and coal quality in Eskom have deteriorated over time, resulting in the performance of the ESP’s not meeting the legislative requirements. Eskom is in the process of introducing various ESP enhancement projects to improve performance and aligning the operating philosophy to comply with the more stringent particulate emission legislation. An ESP efficiency test was conducted at Lethabo Power Station to determine the current state of the plant and performance. The results of the test were compared with the original design base specifications to determine the relevant deficiencies which contribute to high emissions and poor ESP performance. It was aimed to develop an ESP simulation model and validate the outputs with the test data. This study endeavours to demonstrate the greater impact on ESP performance when the ESP is operated outside the design specification. It is further aimed to demonstrate that a solution to the problem of high emissions is not only contributed by the variables within the ESP itself. This study is a coal to stack evaluation considering the ESP variables and the upstream conditions of the ESP that form part of the entire process. The intention of this study is to demonstrate the importance of operating an ESP at the designed parameters and highlight the significance of proper maintenance. It was learned that before any ESP enhancement technology can be implemented, the ESP and upstream conditions must be in accordance with design specifications. The implementation of an ESP enhancement technology will have no merit or justification on a unit that is being operated outside of its design specifications. The results obtained from the ESP simulation model correlated well with the ESP efficiency test data. The expectation of the model to assist operators and engineers to operate ESP’s according to the designer’s specifications was conceded. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

New emission legislation regarding air pollution control, as instructed by the Department of Environmental Affairs (DEA) to Eskom Generation Power Stations, implies a particulate emission limit of 100 mg/Nm3 for all existing power stations by 2015 and 50 mg/Nm3 for all new and existing power stations by the year 2020. Some of Eskom’s power stations which are equipped with Electrostatic Precipitators (ESP’s) were not designed for this stringent legislation. It is also experienced that ESP’s and coal quality in Eskom have deteriorated over time, resulting in the performance of the ESP’s not meeting the legislative requirements. Eskom is in the process of introducing various ESP enhancement projects to improve performance and aligning the operating philosophy to comply with the more stringent particulate emission legislation. An ESP efficiency test was conducted at Lethabo Power Station to determine the current state of the plant and performance. The results of the test were compared with the original design base specifications to determine the relevant deficiencies which contribute to high emissions and poor ESP performance. It was aimed to develop an ESP simulation model and validate the outputs with the test data. This study endeavours to demonstrate the greater impact on ESP performance when the ESP is operated outside the design specification. It is further aimed to demonstrate that a solution to the problem of high emissions is not only contributed by the variables within the ESP itself. This study is a coal to stack evaluation considering the ESP variables and the upstream conditions of the ESP that form part of the entire process. The intention of this study is to demonstrate the importance of operating an ESP at the designed parameters and highlight the significance of proper maintenance. It was learned that before any ESP enhancement technology can be implemented, the ESP and upstream conditions must be in accordance with design specifications. The implementation of an ESP enhancement technology will have no merit or justification on a unit that is being operated outside of its design specifications. The results obtained from the ESP simulation model correlated well with the ESP efficiency test data. The expectation of the model to assist operators and engineers to operate ESP’s according to the designer’s specifications was conceded. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

智慧資本之思潮，源自於北歐，最早發展於瑞典，現今世界各國也相繼投入，其長足發展則在1990年後，而在知識經濟掛帥的年代，其影響到組織的創造與長期競爭優勢，已成為組織最有價值的資產及最有利的競爭武器，而良好的顧客關係就是公司價值具有重大影響的無形資產，也產生顧客資本的價值，若企業能將顧客知識整合到公司流程中，就越能滿足顧客所需要的產品及服務，讓顧客滿意度和忠誠度提高。 本研究選擇個案公司交換式電源供應器之顧客為研究對象，研究目的有四：(一)利用層級分析法找出交換式電源供應器之顧客在選擇供應商時之評選標準及相對權重(二)分析不同貢獻度之顧客在供應商評選標準之權重差異(三)分析不同貢獻度之顧客對個案公司在評選標準上之表現以作為未來顧客關係經營方案的參考(四)對現行交換式電源供應器廠商之顧客資本提出經營建言。 本研究以個案公司交換式電源供應器顧客為問卷對象，並使用層級分析法(AHP)將架構因素設計成問卷，請A、B、C、D等四群顧客依過去顧客期望因素之兩兩比較，得到各層級之各因素在個案公司做顧客期望時的權重。 第一層級研究結果發現，個案公司之四群顧客在顧客期望上，首重品質控制能力與技術設計能力，最不重視地點。 第二、三層級研究結果發現，個案公司之四群顧客在顧客期望上最重視客製化能力、售前諮詢、售後服務、價格水準、產品保證期，而最不重視策略事業關係、過去服務經驗與研究發展支出。 本研究相信，個案公司交換式電源供應器顧客期望透過層級分析法(AHP)的量化分析，找出顧客期望的各因素權重，使企業決策者不會依個人主觀及經驗臆測方式做為決策判斷，而以架構化的決策方式和權重優先次序為依據的客觀方法，相信必能提高顧客滿意度增加公司的經營績效。 / Intellectual Capital originated from North Europe and blossomed in Sweden at the early stage but now the hwole world gets involved. The real expanding was after 1990, now the knowledge-based economy taking the lead, intellectual capital would affect organization’s creative and long-term competitive advantage and also become the most valuable asset and useful weapon. Good customer-relationship is company’s intangible asset and also creates the value of customer capital. If enterprise could compile customers’ knowledge into company’s procedure, it will fulfill customers’ need and increase customers’ satisfaction and loyalty. This research is aimed in the company’s switching power supply’s customers. The main purposes for this research are as follows: 1. Using analytic hierarchy process to figure out the evaluation and relative weighted criteria when customers choosing cuppliers, 2. Analyzing the difference among customers’ who have diverse contribution weighted criteria, 3. By analyzing the difference to generate strategy for future customer relationship maintenance, 4. Offering suggestion to the company operating customer capital. This research is aimed in the company’s switching power supply’s customers with analytic hierarchy process as structure to form the questionnaire. Let A, B, C, D, four groups of customers, to compare two factors each time to get the weighted value for each customer upon each factor. The first tier research comes out that four groups of customers emplyasize quality controla nd technology design ability the most. Disregard location the most. The second and third tiers research come out that customers emplyasize custom, pre-sale consulting, after-sale service, price and guarantee the most. Disregard strategy alliance, previous service experience and RD expense. To conclude, this company could use quantification AHP to rank each customer’s expectation; rather than using subjective judgments or guessing from past experience. I believe this could enhance customer satisfaction well and improve ecompany performance.

The theme of the master´s thesis is design a microphone preamplifier which uses vacuum tube as a main amplifying element. Part of the work is theoretical assumptions for the optimal design and implementation of peripheral involvement, comparing the properties of components used and the resulting parameters of modeled device. The thesis also includes a proposal of the source unit for supplying all parts of the preamplifier. The results are accompanied by circuit simulations and laboratory measurements of the main parameters of the designed device.

The theme of the master´s thesis is design a microphone preamplifier which uses vacuum tube as a main amplifying element. Part of the work is theoretical assumptions for the optimal design and implementation of peripheral involvement, comparing the properties of components used and the resulting parameters of modeled device. The thesis also includes a proposal of the source unit for supplying all parts of the preamplifier. The results are accompanied by circuit simulations and laboratory measurements of the main parameters of the designed device.

Ce travail s’inscrit dans le processus de développement d’un dispositif de traitement de composés organiques volatils (COV) par plasma non-thermique. L’application industrielle des dispositifs de dépollution par plasma froid se heurte à deux limitations majeures que sont une consommation énergétique importante et la formation de sous-produits. Deux axes d’amélioration de l’efficacité énergétique du procédé à décharges sur barrière diélectrique sont explorés dans ce travail de thèse : le mode de dépôt d’énergie dans la décharge et le couplage du réacteur plasma avec un dispositif catalytique. Concernant le premier axe, l’étude a montré que dans le cas des réacteurs DBD étudiés, le paramètre gouvernant la réactivité chimique du plasma à pression atmosphérique était la densité d’énergie, qu’il s’agisse de production d’ozone ou d’élimination d’un COV de la phase gazeuse. L’étude chimique des sous-produits de dégradation par décharge a été conduite pour trois molécules cibles : l’éthanol, l’acétone et la méthyléthylcétone. Dans le cas de l’éthanol, un schéma cinétique 0D est proposé, montrant l’importance de la dissociation dans les mécanismes de dégradation du COV. Pour le second axe exploré, le réacteur plasma a été couplé à un catalyseur. Deux formulations de catalyseurs ont été utilisées, avec et sans métaux précieux. Dans les deux cas, l’activation du catalyseur à basse température par couplage avec le réacteur plasma est démontrée. La dernière partie de l’étude présente les résultats obtenus sur un réacteur plasma à échelle pilote visant à estimer l’impact de l’augmentation des capacités de traitement d’un réacteur DBD sur l’efficacité énergétique du procédé. / This work deals with the development of a VOC removal method by non-thermal plasma which has several advantages including flexibility, compactness and limited investment costs. Further development of this technology needs to overcome major drawbacks such as high energy consumption for high flow rate treatment and the presence of by-products. The first part of the study focuses on the method of discharge energy deposition and the search for optimization of the process energy efficiency. Development of experimental and measurement tools, in particular for the determination of the electrical power injected into the discharge were carefully carried out. The effect of voltage waveform, signal frequency and electrode shape were investigated. The results show that no energy efficiency improvement could be brought by variation of these parameters and that only energy density is important in the gas treatment process. The second part of the study was devoted to the study of conversion of three pollutants (acetone, ethanol and methylethylketone). Formation of by-products was analyzed and a kinetic scheme is proposed for ethanol conversion. To decrease the level of by-products at the reactor outlet, the association between cold plasma and catalysis was investigated. Catalysis was found to allow an improvement in the oxidation of the pollutants and of the discharge by-products. The last part of this work focused on results obtained with a large flow rate plasma reactor to confirm extension of laboratory scale results to larger equipment. Results confirmed that the extension of low flow rate experimental results is possible.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O estudo para o desenvolvimento de uma fonte ininterrupta de energia com possibilidade de uso em sistema fotovoltaico, tem como motivaÃÃo que a larga escala da produÃÃo desse tipo de equipamento possa reduzir o custo dos conversores de eletrÃnica de potÃncia associados a uma instalaÃÃo fotovoltaica. O projeto proporem a uniÃo de topologias de conversores, resultando em uma UPS do tipo on-line com tensÃo de entrada e de saÃda de 220 Volts 60 Hz, potÃncia total de 715VA, rendimento de 88%, isolada em alta freqÃÃncia e com correÃÃo do fator de potÃncia na entrada. Sendo composta por um retificador na entrada com topologia de um conversor em ponte completa alimentado em corrente, esse conversor à responsÃvel por prover a correÃÃo do fator de potÃncia na entrada e da isolaÃÃo galvÃnica em alta freqÃÃncia. Um inversor em ponte completa com filtro LC e modulaÃÃo PWM unipolar, que à capaz de entregar uma tensÃo senoidal para a carga e um conversor boost de alto ganho que cumpre o papel de elevar a tensÃo de 24 Volts do banco de baterias para a tensÃo de 400 Volts do barramento de entrada do inversor. Cada conversor tem seu estudo teÃrico desenvolvido e ao final apÃs as especificaÃÃes e dimensionamentos sÃo mostrados os resultados experimentais do protÃtipo do projeto. Quando o sistema for aproveitado em uma instalaÃÃo fotovoltaica somente o inversor e o conversor boost de alto ganho sÃo utilizados. / The study of the development of initerruptible power supply to be used in a photovoltaic system has as motivation that the wide UPS production scale can reduce the cost of power electronics converters associated with a photovoltaic system. The project proposes a topology of an on-line UPS, with 220 Volts, 60 Hz input/output voltage, 715 VA power, 88% efficiency, High frequency isolation and Power factor correction. The Project consists on a rectifier, it is responsible for providing the input power factor correction and the high frequency isolation. An inverter, it supply the load with a output sinusoidal voltage and a high gain boost converter that increase the voltage from the battery pack up to the inverter. When the project is used in a photovoltaic system, it is only used the inverter and the high gain boost converter.

In the fast growing field of Telecommunications, the back up DC power supply plays a vital role in powering the telecom equipment. This DC power supply is a combination of AC-DC Rectifier coupled with a battery bank to support the load when AC input is not available. Figures 0.1 and 0.2 show the line diagram of the DC power supply. The power supply is the most critical element in a telecom installation and it should be highly reliable in order to have un-interrupted service. (Fig) Besides reliability, power density and cost are the driving forces behind the success of a power supply in the market. Off late, the reach of telecom in the society is very wide covering remote villages and major metros. Given this environment, the power supply is exposed to extreme input conditions. It is desirable to design the power supply capable of withstanding wide AC input conditions. Another advantage is that the rectifier unit will keep the battery charged so that the battery will have long life. This thesis is aimed at designing a 1400W (56V/25A) telecom power supply, keeping in view of the issues expressed above. The aim is to design a Switched Mode Rectifier (SMR) that tolerate wide input voltage variations (90Vac to 300Vac). In addition, the design covers unity input power factor, high efficiency (> 90%), high power density ( ), parallel operation and low cost ( ). Chapter 1 of this thesis covers the context and motivation of the work. Chapter 2 presents the design issues pertaining to power supplies. The normalized description of the power converters is presented. Such a description enables one to compare several circuit topologies in order to make effective design decisions. In a similar way the effectiveness of the switches and mgnetics are presented to enable design decisions in the output stage of the rectifier. Chapter 3 presents the design of the 1400W telecom power supply, keeping in view of the stated specifications. The performance results of the converter are presented in Chapter 4. All the design goals have been met. The design exercise has also given insights into possible further improvements. Contributions from this work and course of future development work are indicated in the concluding chapter.

Es werden Möglichkeiten untersucht, das Kaltstart- und Warmlaufverhalten von Ottomotoren mit Sekundärlufteinblasung zu optimieren. Das für die Untersuchungen eingesetzte, innovative Sekundärlufteinblasesystem mittels Sekundärluftlader weist aufgrund der Baugröße, des Gewichts, der Leistungsfähigkeit und insbesondere der einfachen, thermodynamischen Betätigung Potenziale auf, die bisher eingesetzte Sekundärluftpumpe zu ersetzen. Den experimentellen Untersuchungen wurde die Entwicklung der Abgasgesetzgebung sowie eine theoretische Betrachtung der Entstehungsmechanismen von Abgasemissionen vorangestellt. Mittels eines Simulationsmodells werden die Abhängigkeiten des Sekundärluftladers von den motorischen Randbedingungen abgebildet. Somit kann eine Vorauswahl für das Luftmassenförderverhalten des Sekundärluftladers bei unterschiedlichen Einsatzbereichen getroffen werden. Die im Start- und Warmlauf, ebenso im Lastwechsel, gemessenen Ergebnisse wurden zur Analyse der Emissionsverbesserungsmechanismen eingesetzt. Insbesondere der Einblasezeitpunkt der Sekundärluft und das Hochlaufverhalten des Sekundärluftsystems zeigen einen enormen Einfluss auf die Höhe der Rohemissionen. Eine Gegenüberstellung aller gemessenen Varianten mit Sekundärluftpumpe und Sekundärluftlader zeigt einen deutlichen Emissionsvorteil des Sekundärluftladersystems. Zusätzlich bewirkt der Sekundärluftlader, durch die Bordnetzentlastung eine Motorlastabsenkung bei verbessertem Ansprechverhalten und höherem Sekundärluftmassenstrom. Ergebnis ist eine Verringerung der HC-Rohemissionen zwischen 20% und 30%. Die Vorteile im Gewicht und Bauvolumen sowie der geringere Verkabelungsaufwand runden die deutlichen Vorteile des Sekundärluftladers gegenüber der Sekundärluftpumpe ab. Durchgeführte Untersuchungen bei Tieftemperatur (-7°C) und unter Höhenbedingungen haben ebenfalls Vorteile gegenüber der Sekundärluftpumpe ausgewiesen. Die theoretische Abschätzung des Einsatzfeldes für den Sekundärluftlader ist ab einem Hubraum von 1,2°l Hubraum durchgeführt und als positiv bewertet worden. / The paper investigates possible ways of optimizing the cold-start and warm-up performance of gasoline engines with secondary air injection. Due to its size, weight, performance capability, and especially its simple, thermodynamic operation the innovative secondary air injection system used for the investigations and featuring a secondary air charger has the potential to replace the secondary air pump used to date. The experimental investigations are preceded by the development of exhaust emission legislation and a theoretical analysis of the process leading to exhaust emissions. A simulation model is used to illustrate the dependencies of the secondary air charger on boundary engine conditions. Consequently it is possible to make a preselection for the air mass conducting properties of the secondary air charger in various fields of application. The results obtained by measurement in starting, warm-up, and in load changes, were used to analyze the emission improvement processes. The level of raw emissions is affected enormously by the time of injection of secondary air and the acceleration performance of the secondary air system. A comparison of all the measured variants with the secondary air pump and secondary air charger indicates that the secondary air charger system has a distinct emission advantage. In addition, by relieving the vehicle power supply the secondary air charger brings about a reduction in engine load, improved response, and higher secondary air mass flow. The result is a 20% to 30% reduction in raw HC emissions. The significant advantages over the secondary air pump are rounded off by benefits in terms of weight and bulk volume and a reduction in the amount of wiring. Tests conducted at low temperature (-7°C) and under high altitude conditions have also indicated advantages over the secondary air pump.

這篇研究是依據中國過去十數年空調器成長數量為dependent variables，用回歸分析找出這段期間各項經濟指標中與空調器成長有相關性者為independent factors，所產生的數學模式用來預測中國在2020欲達成小康社會目標時空調器數量。這個分析的應用是依照大陸現行空調器EER值推算2020電力的尖峰負荷，因為空調是造成尖峰負荷主因，所以推論如果將空調器耗能標準提高20%，可以省下3.6個三峽水力發電的裝置容量(18GWx3.6)。也就是大陸供電裝置容量從現在的400GW，增長到2020的900~1000GW時，可節省66GW的裝置容量。 / Chinese market opened to the world since the establishment of Shenzhen Special Economic Zone (SEC) in 1978. Its economic growth starts taking off from 1992 when the 2nd SEC at Shanghai was established. China’s yearly Gross Domestic Products (GDP) growth exceeds 9% on average since then. The trend continued after China entered World Trade Organization (WTO) in 2001. Their GDP reached Rmb18.232 trillions in 2005. Behind the magnificent growth, is the enormous amount of energy and nature resource consumption, thus lead to the environment damage. In 2003, China announced its plan to build a harmonious society (or well-off society or xiao-kang in mandarin) by 2020. This plan outlined the standard of living for the future Chinese. It will be a society composed mainly by the middle class, with a projected 1.5 billion total population, of which 60% will live in the urban area. GDP will grow to 4 times of what it was at 2000; which will make China the third largest economic in the world. However, can China sustain the growth? Is the supply of energy and resource unlimited? Can the rest of the world afford a developed country with 1.5 billion populations without the shortage of nature resource shortage elsewhere? This study reviewed China’s residential and light commercial unitary air conditioning market growth trend from 1995 to 2005. This segment represents 85%~90% of the total Chinese market. The study used several business forecasting methods, to develop a model for estimating the room air conditioner (RAC) and package air conditioner (PAC) market growth till 2020, by considering various social and economical factors such as GDP growth, construction of new buildings, disposal income (DPI) and retail price changes. The forecast can be used to estimate the peak time electrical power demand with the Energy Efficiency Ratio (EER: rated Cooling Capacity in Watt / Power Input in Watt) of RAC and PAC required by the code. Our study found that China should impose a much more stringent EER code in order to reduce peak electrical power demand and avoid supply shortage during the summer, since the economy is predicted to continue to outgrow the power supply. The alternative is to build more new power plant only to meet the summer peak load, while most other time of the year the plants may stay idle. According to Asia Pacific Economics Cooperation, Energy Standard Information System (APEC ESIS) current China EER requirement is around 25% below Taiwan, and most developed countries. Japan Air Conditioning Journal (JARN) and Building Services Research and Information Association from UK (BSRIA) reported that the size of China’s air conditioning market size exceeded Japan in 2003 to become the world second largest in the world, after only the United States. China now manufactures more mini split than any other places in the world. There should be no technical difficulty to adopt the more stringent code to help reducing the peak load demand from air conditioning, since most advance technologies are now available to the market and local manufacturers. Some Chinese air conditioning manufacturers already have a capacity surplus. Exporting their products to the developed countries such as the US and Japan, will require them to meet the EER code of the country of destination. This may speed up the introduction of higher EER design products in the local Chinese market.