Dissertationen zum Thema „Cave Weta“

Magister Commercii - MCom
In order to comply with the Air Quality Act 2010, Eskom will have to install flue gas desulphurisation (FGD) plants for both new and old power stations. Wet-flue gas desulphurisation (wet-FGD) is adopted world-wide as an effective flue gas treatment technology and therefore will be adopted by Eskom. During the process of desulphurisation, the flue gas is stripped of SO2 but gains a substantial amount of water. Sustaining this process requires a continuous supply of fresh water, a scarce resource in many places where power stations are built. This research investigates the economic feasibility of technologies capable of recovering water from flue gas. The following technologies were considered to capture water vapour from flue gas taking Eskom’s Medupi Power Station as a case study; condensing heat exchanger technology, desiccant drying systems and membrane technology using membrane modules developed by other students in this project. The water vapour selective membrane technology turned out to be superior.

Suicide is a complex phenomenon, which can be prevented if intensive and continuous research is being done to determine tendencies and to compile profiles of high-risk cases. Suicide prevention is currently a high priority in the South African Police Service (SAPS). In the Northern Cape various potential stressors, such as a high crime level, lack of resources and vast distances to travel are some of the challenges members of the police service face. Increased rates of post-traumatic stress, alcohol abuse, depression and suicides are found in research with police members. Research that was done in the SAPS shows that the number of suicide among police officers increased from 11 suicides per 10 000 during 1999 to 13 suicides per 10 000 during 2000. The numbers of suicides in the SAPS in the Northern Cape are of the highest of all the Provinces. Suicide ideation can be considered an early marker for more serious suicidal behaviour. However, there is a lack of empirical research systematically investigating suicide ideation and possible correlates thereof in the SAPS in the Northern Cape. This research investigated the relationship between suicide ideation, stress and coping within SAPS in the Northern Cape. The aim of this research was to determine the level of suicide ideation and possible correlates thereof. Further aims included predicting suicide ideation by meqs of stress and coping variables. The research method for this article consists out of a brief literature review and an empirical study. A cross sectional survey design was used. A random sample (n=274) as taken of members from police stations in the Northern Cape. The Adult Suicide Ideation Questionnaire (ASIQ), Police Stress Inventory (PSI), COPE Questionnaire and a biographical questionnaire were administered. Descriptive and inferential statistics were used to analyse the data. Results indicated that 3.28 % of the sample showed serious levels of suicide ideation. It was shown that previous suicide attempts, medical status, passive coping, problem-focussed coping, police stressors and job demands could be used to predict suicide ideation.
Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2004.

Tanzania is close to reach one of the Millennium Development Goals; to reduce child mortality with two-thirds between 1990 until 2015. This qualitative case study focuses on under-five children’s health in Babati district, situated in the north-west of Tanzania. The empirical data used in this thesis has been collected through interviews with health personnel and mothers during three weeks in February to March 2012. The purpose of the study has been to identify direct and underlying reasons causing child mortality, and to investigate what measures are needed to improve the situation. The most prominent diseases creating death amongst children are pneumonia and malaria, and also diarrheal diseases are common. The prevalence of the diseases differs from wet and dry season, whereas there are more cases of illness and death during the wet season. Malaria and pneumonia are common causes of death during the wet season, and diarrheal diseases are more common during the dry season. Underlying reasons affecting child mortality in Babati district are the lack of infrastructure, such as few well-functioning roads to the main hospitals which affects the rural population in particular. Also the limited access to transport is a vast problem when there is acute illness or childbirth. The clinics available in Babati district are poorly equipped and have a lack of personnel, creating a stressful situation for both healthcare workers and patients. More governmental funds and infrastructure is needed in the area to be able to create a sustainable situation for future children.
Tanzania är nära att nå ett av Milleniemålen; att reducera barnadödligheten med två tredjedelar mellan 1990 till 2015. Den här kvalitativa fallstudien fokuserar på barn under fem års hälsosituation i Babati distriktet, beläget i nordvästra Tanzania. De empiriska data som används i studien har samlats genom intervjuer med sjukvårdspersonal och mödrar under tre veckors tid under februari och mars 2012. Syftet med studien har varit att identifiera direkta och indirekta orsaker till barnadödlighet, samt att undersöka vilka förbättringar som krävs för att förbättra situationen. De mest framträdande orsakerna för barnadödlighet är lunginflammation och malaria, men också sjukdomar kopplade till diarré är vanligt förekommande.  Förekomsten av sjukdomarna varierar beroende på om det är regnsäsong eller torrperiod. Under regnsäsongen så är det flest sjukdoms- och dödsfall, och lunginflammation och malaria är mest förekommande medans diarré är vanligast under torrperioden. Bakomliggande orsaker som påverkar barnadödlighet i Babati är bristen på infrastruktur, få välfungerande vägar till huvudsjukhusen vilket framför allt påverkar den rurala befolkningen. Den begränsade tillgången till transport är ett vidsträckt problem vid akut sjukdom eller förlossning. Klinikerna i Babati distriktet är undermåligt utrustade och har personalbrist, vilket skapar en ohållbar situation för både sjukvårdspersonalen och patienterna. Mer statliga resurser och infrastruktur behövs i området för att kunna skapa en hållbar situation för framtidens barn.
Miljö och utveckling i syd

>Magister Scientiae - MSc
Fly ash is the major waste material produced by power plants in the combustion of coal to generate electricity. The main constituents of fly ash are Si, Al, Fe and Ca with smaller amount of S, Mn, Na, K, and traces of many other elements such as Co, Cd, As, Se, Zn, Mo, Pb, B, Cu and Ni. Fly ash is usually disposed either by dry or wet disposal methods. These disposal methods have raised major environmental concerns due to the potential leaching of chemical species from the ash heap by ingress of rainfall and brine used to transport the fly ash to the dam. This study focuses on the changes in chemical composition, morphology and mineral phases due to weathering, of coal fly ash co-disposed with brine over 20 years at Sasol Secunda ash dump in Mpumalanga Province, South Africa. The design and operation of the Secunda ash dump presupposes that the ash dump may act as a sink for the salts which originated from chemicals used for normal operation in the plants. The majority of these salts come from the brines generated during desalination and raw water regeneration. The aim of this study is to ascertain if the ash dump could serve as a sustainable salt sink.Samples were drawn along the depth of two drilled cores (S1 and S3) from the weathered Secunda ash dump and analysed in conjunction with the fresh (unweathered) Secunda fly ash taken from the fly ash hoppers for comparative analysis. Scanning electron microscopy (SEM), X-ray diffractive (XRD) and X-ray fluorescence (XRF) spectrometry were employed to obtain a detailed morphological, mineralogical and bulk chemical composition of all the samples. Pore water analysis was used to determine the pH, EC and moisture content of fly ash samples. A five step sequential chemical extraction procedure was used to establish the geochemical association of particular elements with various mineral phases. The total acid digestion test was also used to determine the total elemental compositions of the Secunda fly ash samples. The SEM results showed that the fly ashes consist of irregular and numerous spherically shaped particles. Changes (encrustations, etchings and corrosion) in the morphologies of the weathered ash particles were also observed. The XRD results revealed quartz, mullite, lime and calcite as the major mineral phases. Other minerals identified in very minor quantities in the drilled Secunda ash core that were dried prior to analysis were halite, kaolinite, nitratine, bassanite, microline. and hydrophitte. These phases may have formed during sample handling. XRF investigation revealed that the major oxides present in the dumped ash samples were SiO₂, A₂2O₃, CaO, Fe₂O₃, MgO, Na₂O, TiO₂ and the minor elements present were K₂O, P₂O₅, SO₃ and MnO. The sum of the mean values of the % composition of SiO₂, Al₂O₃, and Fe₂O₃ was 70.19 %, and 72.94 % for the two drilled ash core samples (S1 and S3) respectively, and 78.67 % for the fresh ash which shows the significant alteration of the Si, Al and Fe content in the ash matrix over time. The fly ash is classified as Class F using the ASTM C 618 standards. The loss on ignition (LOI) which is an indication of unburned carbon or organic content was 4.78 %, 13.45 % and 8.32 % for the fresh ash, drilled ash cores S1 and S3 respectively. The high LOI values for the drilled ash cores could indicate high hydrocarbon content in the ash dump because of co-disposal practises where hydrocarbon waste are included in the brine stream for disposal on the ash. While the ash samples from the surface appeared dry, moisture content (MC) analysis showed that there is considerable water entrained in the fly ash dump. The fresh ash MC was 1.8 % while core S1 ranged from 41.4 – 73.2 %; core S3 ranged from 21.7 – 76.4 %. The variations in the MC values can be attributed to uneven flow paths due to inconsistent placement conditions or variations in ambient weather conditions during placement. The fresh fly ash (n=3) had a pH of 12.38±0.15, EC value of 4.98±0.03 mS/cm and TDS value of 2.68±0.03 g/L, the pH of the drilled ash core S1 (n=35) was 10.04 ±0.50, the EC value was 1.08±0.14 mS/cm and the TDS value was 0.64 ±0.08 g/L. Core S3 (n=66) had pH of 11.04±0.09; EC was 0.99 ±0.03 and TDS was 0.57 ± 0.01. The changes in pH values can be attributed to the dissolution and flushing out from the dump basic alkaline oxides like CaO and MgO These variations in pH values shows that the fly ash is acidifying over time and metal mobility can be expected under these conditions. The large decrease of EC in the drilled ash cores S1 and S3 compared to the fresh ash indicated a major loss of ionic species over time in the ash dump. The sequential extraction scheme revealed that the elements Al, Si, Ca, Mg, Ba, Sr, Fe, Mn, Na, K, As, Pb, Cr, Mo, Cu, Ni and Zn are present in Secunda fresh and weathered fly ash and are partitioned between the water soluble, exchangeable, carbonate, iron and manganese, and residual fractions of the coal fly ash. It also showed that the trace elements As, Pb, Cr, Mo, Cu, Ni and Zn do not show permanent association with particular mineral phases as a continuous partitioning between different mineral phases was observed in the weathered drilled core. Generally, all the elements had the highest concentration in the residual fraction. But it was evident that the labile phase (water soluble, exchangeable and carbonate fractions) had fairly high concentrations of Si (± 6.5 %), Al (± 6.5 %), Ca (±10 %), Mg (± 5.5 %), Ba (± 7.5 %),Sr (± 7.5 %), Na (± 12 %) and K (± 12 %) for the Secunda drilled ash core (S1 and S3) and fresh fly ash samples. This indicates that these species can leach easily upon water ingress and could pose a danger to the environment. Na and K had the highest concentrations leached out in the labile phase in all the ash samples. The amount of Na leached out of the drilled Secunda ash core in the labile phase was 13.21 % of 18584.26 mg/kg in the five geochemical phases of core S1; and 9.59 % of 11600.17 mg/kg in the five geochemical phases of core S3 while the fresh Secunda fly ash leached out 11.28 % of 16306.30 mg/kg of Na in the five geochemical phases. This study provided significant insight into the pore water chemistry, morphology, mineralogy and chemical composition and the elemental distribution pattern of the major and trace elements in the Secunda fly ash and weathered drilled Secunda ashm core S1 and S3. Though results from XRF analysis and the sequential extraction scheme shows that Na, K, S, Ca and Mg were slightly captured from the co-disposed brine by the Secunda fly ash, these species were however released in the labile phase. Hence there was no significant retention of these species in the ash dump. The amount of these species retained in the weathered ash were (0.26 % and 0.55 %) for Na, (0.02 % and 0.34 %) for K, (0.08 % and 0.06 %) for S, (0.94 % and 0.01 %) for Ca and (0.37 % and 0.96 %) for Mg in drilled ash cores S1 and S3 respectively. This poor retention of Na K, S, Ca and Mg which are major components of Sasol Secunda brine in the drilled ash cores S1 and S3 clearly shows the unsustainability of the Secunda fly ash dump as a salt sink.

Soil mixing is a procedure that has proven to be effective for loose or soft compressible soils. The method stabilizes the soil in-place using specialized augers, tillers, or paddles that inject grout or dry cementitious powders as part of the mixing process. The Federal Highway Administration design manual for soil mixing helps to estimate the required amount of cementitious binder to produce a target design strength. However, it is biased towards inorganic soils and only mentions caution when confronting organic soils which usually come with a high water table, moisture content and void volume. The Swedish Deep Stabilization Research Centre cited studies with highly organic soils in regards to soil mixing and suggested that organic soils may need to reach a ‘threshold’ of cement content before strength gain can occur. The University of South Florida also conducted a study on highly organic soils and was able to confirm this concept. USF also proposed a threshold selection curve based on the organic content. This thesis extends this concept to the bench scale testing of multiple full scale field studies. This thesis will conclude with the presentation of new threshold curves based on the new data from the added field case studies. Given that there were variable binders and soil types used in the data analyzed, these threshold curves are dependent upon soil type and binder type, thus expanding upon the curve previously suggested.

>Magister Scientiae - MSc
Improved knowledge is required on the quantity and source of water resources, particularly evident during periods of drought currently being faced in South Africa. There is inadequate knowledge with regards to the flood attenuating properties of wetlands, particularly evident in the ungauged catchments of Southern Africa. This study aims to improve the knowledge on the contribution of flow from tributaries with headwaters in mountainous regions to low lying areas and the effects of wetlands on river flow patterns. Several river flow monitoring sites were established along the major upper tributaries of the Nuwejaars River at which daily water levels were recorded and bi-weekly discharge measurements were conducted. Weather data was collected using four automatic weather stations and three automatic rain gauges’ setup throughout the catchment. Rainfall data coupled with rating curves and daily discharges were used to assess the flow responses of these tributaries to rainfall events. Additionally, stable isotope analysis and basic water quality analysis was used to determine the major sources of flow within the major tributaries. The rainfall and river flow data collected, coupled with the characterization of the wetland was used to determine the flood attenuation capabilities of the wetland. Lastly, a conceptual model based on a basic water balance was developed to further explain the role of the wetland and its effects on river flows. The results showed a 27-hour lag time in peak flows from the upper tributaries at the inflows of the wetland to the outflow. Two of the upper tributaries had flow throughout the year and were fed by springs in the upper mountainous regions of the catchment and all tributaries were largely reliant on rainfall for peak flows. The temporary storage of flows within the wetland occurred as a result of the Nuwejaars River bursting its banks, filling of pools, or ponds and the Voëlvlei Lake. It was concluded that the wetland increased the travel time and decreased the magnitude of flows of the Nuwejaars River. However, due to the fact that wetlands are interlinked on a catchment scale and have a collective effect on flood attenuation this study may be improved by looking at the wetlands within the catchment holistically.

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Nos últimos anos a quantidade de dados armazenados diarimente em empresas e instituições aumentou consideravelmente e um dos motivos que contribuiu para isso é a crescente importân- cia dada à informação. De forma geral, esses dados são meramente armazenados e, portanto, subutilizados pelos seus detentores, enquanto poderiam ser estudados a fim de obter novos co- nhecimentos, informações e relacionamentos. Neste contexto, surge o processo de descoberta de conhecimento em banco de dados. Este trabalho apresenta uma introdução a banco de dados, uma revisão bibliográfica sobre o processo de descoberta de conhecimento em banco de dados, a descrição de cada etapa deste processo, uma explanação sobre as tarefas de agrupamento e classificação, além de resumir brevemente as técnicas de particionamento e árvore de decisão. É exposto um estudo sobre o sistema Weka, em que apresenta-se conceitos, funcionalidades e exemplifica-se diversas formas de utilização do sistema. O objetivo principal deste trabalho é propor uma metodologia para descoberta de novos conhecimentos em bancos de dados acadê- micos baseada no processo de descoberta de conhecimento em banco de dados, sendo esta uma metodologia mais simplificada e de execução mais direcionada. Como parte da metodologia este trabalho contribui ainda com uma aplicação desenvolvida em Python como forma de apoio a etapas da metodologia. A metodologia proposta conta com a ferramenta Weka para execução dos algoritmos de data mining e prevê a execução das tarefas de agrupamento e classifica- ção. Por fim o trabalho retrata dois estudos de caso envolvendo bancos de dados acadêmicos reais e a execução de todas as etapas da metodologia proposta, com a utilização do sistema Weka. Os estudos de caso abordam as tarefas de agrupamento e classificação e as técnicas de particionamento e árvores de decisão, com a utilização dos algoritmos SimpleKMeans e J4.8, respectivamente. Os resultados obtidos através dos estudos mostram que a metodologia pro- posta é capaz de gerar conhecimentos novos e úteis, tanto na análise de dados de desempenho acadêmico quanto na análise de dados socioeconômicos dos alunos.
In the past years the amount of data stored daily in companies increased considerably and one of the reasons that contributed to this fact is the increasing importance given to information. In general these data are merely stored and therefore underused by its owners, while they could be studied in order to find out new knowledge, information and relationship. In this context, the knowledge discovery in database process arises. This work presents an introduction to databa- ses, a bibliographic review about the knowledge discovery in databases process, a description of each step of this process, an explanation about the clustering and classification tasks and the summarization os the partition and decision tree techniques. A study of the Weka system is shown, in wich are presented concepts, functionalities and examples of use forms for the sys- tem. The main objective of this work is the proposal of a methodology for knowledge discovery in academic databases based on the KDD process. The presented methodology is a more sim- plified and directed version of the KDD. As part of the methodology this work also presents an application developed in Python programming language as a support tool for the methodology steps. The presented methodology uses the Weka tool for running the data mining algorithms and considers the clustering and classification tasks. Lastly this work describes two case stu- dies involving real academic databases and the execution of all the steps from the proposted methodology using the Weka system. The case studies addresses the clustering and classifica- tion tasks, as well as the partitioning and decision trees techniques, using the SimpleKMeans and J4.8 algorithms respectively. The obtained results show that the methodology is capable of generating new and useful knowledge, both by analyzing academic performance data and by analyzing students’ socioeconomic data.

This thesis examines the effectiveness of tourism as an agent of rural development, focusing on culture and nature-based destinations in the 'developing world'. The village of Desa Senaru at Gunung Rinjani National Park in Lombok Island, Indonesia, served as a case study. Conservation agencies frequently support tourism development as a sustainable alternative to more extractive resource uses. Integrated conservation models, in particular, present 'eco'tourism as an effective instrument to enhance rural livelihoods while protecting the environment. Alongside international aid agencies, the World Tourism Organisation (UNWTO) also promotes the sector for its poverty reduction potential in 'third world' countries. Rural communities hold concomitant expectations of tourism's socio-cultural development potential. Furthermore, 'eco'tourism functions as a growing niche market for the globally expanding tourism industry and local entrepreneurs. As such it fits well into the economic rationale that underpins neo-liberal market strategies. With such a diversity of interests at stake, the question "What kind of business is tourism?" has become more complex, critical and pertinent than ever before. Informed by development theories and the sociology of tourism, this analysis focuses on the multiple dichotomies that characterise 'third world' tourism. In the case of tourism development in Desa Senaru, several paradoxical outcomes have been identified. The most profound of these is the 'social justice paradox' that describes the way tourism costs and benefits are distributed within a heterogeneous community of native residents and migrant settlers. While most of the case study's tourism attractions are part of the cultural heritage of the wetu telu Sasak hamlets, these derive few economic benefits and struggle to access the new development opportunities 'eco'tourism offers. Filtered and directed by historical political relations, several key barriers to a meaningful participation of these native people in the 'business of tourism' have been identified. These include the prevailing conditions of education, culture, ethnicity, socio-economy, location, mobility, skills and knowledge. Expectations of 'eco'tourism as a 'soft' industry analysed vis-à-vis the global biosphere effects of air transport highlight the 'eco-paradox' of international tourism. The cleavage between the poverty-focused aid policies of the New Zealand Government and an integrated conservation project, whose benefits local elites have largely captured, illustrates the 'project paradox' of rural tourism development programmes. In the 'development paradox' of cultural tourism, symbolic constructs of 'otherness' (such as 'aesthetic poverty') contrast with various development agendas; in their search for the 'real' traditional village, for example, the tourists reject all signifiers of material progress and modernity. Their curious gaze at the spiritual practices and everyday life world of the wetu telu villagers manifests opposite a recent history of state-sanctioned religious discrimination. Taken together, these paradoxical local outcomes emphasize the significance of power relations and political dimensions within the globally expanding 'business of tourism'. Ethical considerations are an important aspect of this study as they contribute towards an 'ethic of development' that, so far, has found little theoretical resonance amongst scholars of tourism studies. To operationalise the ethical concerns raised, the thesis posits a model of a holistic approach to development. This recognises tourism as a complex open system.

Surface treatments are often used in the manufacturing industry to change the surface of a product, including its related properties and functions. The occurrence of degradation and corrosion in surface treatment processes can lead to critical breakdowns over time. Critical breakdowns may impair the properties of the products and shorten their service life, which causes increased lead times or additional costs in the form of rework or scrapping.  Prevention of critical breakdowns due to machine component failure requires a carefully selected maintenance policy. Predictive maintenance is used to anticipate equipment failures to allow for maintenance scheduling before component failure. Developing predictive maintenance policies for surface treatment processes is problematic due to the vast number of attributes to consider in modern surface treatment processes. The emergence of smart sensors and big data has led companies to pursue predictive maintenance. A company that strives for predictive maintenance of its surface treatment processes is Seco Tools in Fagersta. The purpose of this master's thesis has been to investigate the occurrence of critical breakdowns and failures in the machine components of the chemical vapor deposition and post-treatment wet blasting processes by mapping the interaction between its respective process variables and their impact on critical breakdowns. The work has been conducted as a Six Sigma project utilizing the problem-solving methodology DMAIC.  Critical breakdowns were investigated combining principal component analysis (PCA), computational fluid dynamics (CFD), and statistical process control (SPC) to create an understanding of the failures in both processes. For both processes, two predictive solutions were created: one short-term solution utilizing existing dashboards and one long-term solution utilizing a PCA model and an Orthogonal Partial Least Squares (OPLS) regression model for batch statistical process control (BSPC). The short-term solutions were verified and implemented during the master's thesis at Seco Tools. Recommendations were given for future implementation of the long-term solutions. In this thesis, insights are shared regarding the applicability of OPLS and Partial Least Squares (PLS) regression models for batch monitoring of the CVD process. We also demonstrate that the prediction of a certain critical breakdown, clogging of the aluminum generator in the CVD process, can be accomplished through the use of SPC. For the wet blasting process, a PCA methodology is suggested to be effective for visualizing breakdowns.

In karst areas relationships between activities occurring on the surface and the overall health of the subsurface environment are often highly interconnected. However, the complex nature of karst flow systems can often make identification of these connections difficult. Carroll Cave, a large stream cave system located in the central Missouri Ozarks, is known for its biological and speleological significance. A dye tracing project to delineate a Carroll Cave recharge area through dye tracing has identified an area of 18.5 km2 which contributes water to the cave. The water from Thunder River within Carroll Cave was positively traced to eight springs of the thirteen springs at a distributary spring system known as Toronto Springs. Through examination of the geochemistry of the individual springs, differences in water chemistry between the various outlets has become evident. Additional work with YSI Sonde dataloggers and consideration of carbonate chemistry relationships has sought to further define the variations in hydrochemical behavior, thus aiding in the discrimination potential spring sources. Primary sources thought to contribute water to the spring system include Carroll Cave and Wet Glaize Creek, with some minor influence from other losing streams in the vicinity. Seepage runs along Wet Glaize Creek have also identified major losing reaches, in close proximity to structural features, which may contribute water to Toronto Springs. Examination of the measured parameters and derived have identified that Carroll Cave and Wet Glaize Creek are the primary end members for Ca2+, Mg2+, HCO3-, specific conductance, and temperature. Using these parameters a two end member mixing model has been developed which describes the mixing zone setting at Toronto Springs and calculates the average proportions of flow contributions by the end members. By using a multi-proxy approach of dye tracing, seepage runs, and geochemistry for the individual springs, the source waters and pathways for the springs at Toronto Springs have been identified.

碩士
淡江大學
化學工程與材料工程學系碩士班
106
This technical report is about the project plan of a Wet Station during the period of intern of Ding Cheng International Co., Ltd. The work in the project is to assist in the collection of related information such as hardware equipment, electrical control and software of this Wet Station, and to write a manual for the operation of the Wet Station. The equipment improving is based on the combination of two different system models. In terms of hardware, the piping of each acid bath unit is redesigned, and other equipment-related parts are replaced. The addition of equipment components to the machine is a functional design of the protection mechanism such as sensors, quick drain pump, and fast refill water valves in the acid bath unit. In order to replace the bath plate, the chemical resistance of the plate was tested. In terms of software, the software technology part of the computer control is very difficult to rewrite. In addition to integrating the control instructions of the machine, it also redesigned the control interface of the operating system and increased the Chemical Mode Select system''s function of rapid acid exchange. These are convenient and quick control process steps for the operator. About the chemical resistance test of new and old plates is based on considerations of material replacement for the acid bath unit and plate suppliers. Experimental plates were placed in an acidic environment and closed system conditions, and the plates were observed for changes in surface and weight after controlling for different experimental times. The experimental results showed that the old and new plate surface appear the phenomenon of aging and the color was darkened. However, there were no signs of destructive corrosion, embrittlement, or cracking on the surface, and there is no obvious difference in weight change. The results of this experiment can provide a reference for customers and vendors as replacement plates.

碩士
國立雲林科技大學
企業管理系
106
ABSTRACT This study uses in-depth interviews and secondary data, targeting Taiwan listed company A-Wea. According to the research and suggestions of past scholars, analyzing of the equity structure design, role of venture capital, listed on the stock exchange before VC sells equity in the early stage of A-Wea company. And use organizational change steps to discuss for president encountered a large number of employees leaving the company. The result of this study as follow: 1. In the early stage of startup, the proper equity structure design was not done. It would easily lead to the replacement of the operating rights of the major shareholder or management team in the company. 2. In the case of start-up managers who lack resources and use equity for the growth of the company and the future value of the company, the company will easily lose control of the company after it grows. 3. In the Taiwan legal regulations, if manager want to have the managerial authority in the company, you must raise your holdings to 33%. 4. Before VC sells their equity, manager must do financial planning and holding 33% of the shares or more than half of the seats on the board of directors, as opposed to selling the shares to the market, the friends and relatives which can reduce the risk of the company's control and continue to operate the company. 5. For the operators, after a large number of employees leave the company, they can be used as an opportunity for organizational reconstruction, and properly manage the changes and development that will help the future growth of the company. Keyword: Equity design, Venture Capital, A large number of employee leave

碩士
國立交通大學
工學院碩士在職專班產業安全與防災組
99
As manufacturing technology advances, investment in the construction of wafer FAB is large. In the past, to build an 8” FAB requires NTD 30 billion yuan, and now to build a 12” FAB requires at least NTD 100 billion yuan. Among the investment in the semiconductor industry, the expenditure for the purchase of machine equipment is the highest, accounting for about 60% to 70%. As purchasing second-hand equipment can reduce costs for factory Construction and depreciating machines, competitive advantage can be enhanced. However, it is difficult for the buyers to control the durability and safety of second-hand equipment, particularly the material of the wet bench in the past is mostly polypropylene (PP) or polyvinyl chloride (PVC). They are all flammable, and when burnt, high heat and large amount of smoke will be produced. Moreover, there are heating devices and flammable chemicals inside the machine, so it’s very easy to catch fire in the past, and the loss is also very serious. Therefore the wet bench areas are regarded as the focus of fire protection by all factories. This study takes a model of wet bench equipment in the 8” FAB as the object for assessment, discussing risks in safety and fire of running many-year-old machines through the risks in the machines’ internal tank, electrical units, chemical supply, as well as the material hardware, safety protection and interlocking devices.

碩士
開南大學
商學院碩士在職專班
102
As a result of dense industrial clusters in Taiwan’s wet process sector there is a need to shorten the distance of communication and also make more possibilities for communication. In order to construct effective communication for a project’s technical team it is first necessary to explore the factors involved. After literature reviews and expert interviews, this study constructs three dimensions and 15 criteria for the purpose of evaluating effective communication for a project technical team. A survey elicited the opinions of 30 experts in the wet process sector by questionnaire. The fuzzy linguistic preference relation (Fuzzy LinPreRa) approach is employed to assess the importance of these evaluation criteria. The goal is to help the project technical team pay attention to matters involved in the process of constructing effective communication. 　　The results of the survey indicate that in order to construct effective communication for communication conduct for a project technical team, we should focus on crisis management; in particular, when a crisis occurs, it is necessary to manage it prudently when making statements to specific persons or indefinite ones; in order to reach the communication objective, we need to clarify communication purposes carefully and confirm the target before communicating; communication frequency is another important point, the appropriate frequency of communicating will promote information renewal, and ensure the information on both sides was identical. 　　This study suggests that we should apply Agile Project Management to assist in executing the project. When executing the project, we should not focus on only one kind of project management methods, but instead we should apply Agile Project Management and Traditional Project Management depending on the case so as to achieve the goal of the project.

碩士
國立交通大學
工學院產業安全與防災學程
102
In semiconductor processes, the wet bench uses the most organic solvents. During the process, the wafer is dried by heating at high temperature until evaporation occurs which leads to the potential risk of fire and explosion. Among all organic solvents, isopropyl alcohol has the lowest minimum ignition energy of 0.65 mJ, which is so low that even a spark of static electricity could ignite it leading to fire and explosion hazard. Numerous records and documents have pointed out the potential risk of company property and personnel safety if the safety device of the relevant production line is inadequate. When using the flammable organic solvent bench, fire extinguishing equipment is necessary because of the potential fire hazard. With the advances of semiconductor processes and the improvement of equipments, potential risks also evolve. The accompanied improvement and upgrade of the extinguishing system to an intelligent safety surveillance system includes such functions as graphical control, a back-up assistance system and responsible management organization etc. Although these functions decrease the probability of risks, the issues of incompetent technicians, unfamiliar operation and the troubleshooting of the equipment still require improvement. This research focuses on the safety surveillance system of the wet bench in a semiconductor factory and studies its failure module and FMEA (Failure Modes and Effects Analysis). The failure frequency of the equipment components and human negligence are discussed in order to control the encountered disaster or malfunction effectively and reduce the frequency of fire hazard and production interruption in the wet bench. It is hoped this will help the sustainable operation of the company.

碩士
國立中興大學
食品科學系
92
Abstract Rice cake , such as salt rice cake、radish rice cake、rice cup cake , are popular Chinese-style rice processed food. Mainly the raw material is Indica rice utilizing gelatinizing characteristic of rice pastes , and then we can get rice production with good-looking appearance and fine texture. In the experiment , the nation TNuS19 rice was adopted as the raw material. The researcher focused on effect of the pre-gelatinization of wet milling rice paste under the conditon of different ratio of rice and water as 1:2,1:3, and 1:4. The analyzed items included chemical composition of rice , rapid viscosity analyze（RVA）, rice paste particle size , scanning electron micrographs（SEM）, normal and polarized light photomicrographs , colorness , moisture content , texture , hollowness , sensory evaluation. The experimental results showed below：the rice kernel adopted as the raw material absorbed equivalently（0.17g water/ g rice） after being steeped for 40 minutes. After dried by the centrifuge dehumidifier , the rice flours were tested moisture and showed the moisture 43%~44% or so . The Rapid Visco Analyze（RVA） showed dry milled rice flours have lower viscosity than frozen rice paste ; the morphological structure photographed by Scanning electron microscopy of rice kernel granule with dry milled has lower completeness. The physical properties and texture experiments , rice paste pre-gelatinization process、moisture content affect the hollowness、springiness and chewiness of the products. The rice and water ratio 1:2 was more harder , but 1:4 was softer. Microstructures of 1:2,1:3,1:4 we observed photographed by SEM are from compactness to sponginess. The result of sensory evaluation showed that rice and water ratio 1:3 is more popular among the evaluators. In conclusion , after rice steeping for 40 minutes , wet-milled rice paste with 1:3 , set gelatization time 180 seconds , finally in the process of steaming , following procedure above we can get better products. In addition , rice cake produced from wet-milled rice paste have better quality in texture than that produced from air-hot dry rice flours.

碩士
長庚大學
商管專業學院碩士學位學程在職專班經營管理組
104
For any semiconductor company facing process conversion, purchasing too much machinery may result in waste and cause clean room space idle; but if too little purchased, then insufficient capacity can lead to the risk of product shortage. Hence, it has been an important issue for semiconductor companies to decide the “optimal” number of fab machines. By taking a semiconductor company as an example, this thesis carries out the cost-benefit analysis on the machine conversion problem of wet processes. This study considers the case of two different wet-chemical washing machines (DHF and SPM), and builds a mathematical programming model to find the benefit-maximizing number of machines procured and channel number of conversion process, subject to the constraints on capacity requirements, yield level and conversion standards. Research results include (a) the number of DHF machines is more sensitive to the cost-benefit analysis; (b) when the marginal yield rate of SPM machines is less than 0.02%, the conversion to SPM group contributes nothing to the problem; and finally (c) benefit of machine conversion naturally decreases as the unit price of single SPM machine increases, and no good to add any SPM machine when it costs more than NT$ 195 million. Conclusions of this thesis on how the number of channels in the wet process, yield and the unit price affect the benefit in machine conversion problem may provide a guideline to the semiconductor industry in making machinery investment decision.

碩士
國立臺灣大學
事業經營碩士在職學位學程
107
In 2017, the total market value of Taiwan''s semiconductor industry supply chain was reached to NT$2.46, which ranking is No.3 of the world, and it took the lead in the foundry and semiconductor manufacturing field. How Taiwan can have a unique market position in this industry, the complete supply chain inside Taiwan shows a significant meaning. In addition to leading technical competitiveness comparing with South Korea, United States, and Japan, Taiwan Semiconductor''s complete upstream supply chain not only allows customers to produce continuously, but also supplies high-quality, low-cost wet chemicals to semiconductor customer, which empower the industry to have low cost and efficient in manufacturing. In the paper, the electronic wet chemical industry selected the leading P company to conduct a case study to analyze its origins from the company''s founding, strategy selection from target concentration, cost leadership, to the current evolution to differentiation strategy, and to be internationally. Understanding P company’s establishment to expand market share and gradually develop a multi-product portfolio can be used as a reference for the development planning of one company''s growth and resource allocation.

碩士
國立清華大學
工業工程與工程管理學系
95
Semiconductor wafer fabrication facilities face a variety of challenges. The combination of shrinking device geometries and increasing interconnect levels is rapidly increasing process complexity. It is leading to higher manufacturing costs and longer cycle times. Cycle time is one of the most important issues in semiconductor industry. In wafer fabrication processes, batch process steps account for approximately 25%~ 30% of the overall cycle time. This is caused by the long process times, batch sizes, hot lots and the batching rule of the batch process. These batch processes machines such as furnace and wet bench has major impact on the total cycle time. Comparing to batch process machines, single wafer process (SWP) machines enable shorter cycle time to promote faster product development, quicker ramp up of new products and earlier yield correction leading to economic benefits. However, the cost/benefit tradeoff is the major concern for a Fab to replace batch process machines with single wafer process machines. This study uses discrete-event simulation and Taguchi methods to investigate optimal process factors (i.e. hot lot ratio, batching rule, time constraint, and etc) of batch process in furnace and wet bench areas. Results of simulation proved the batch process in furnace area and hot lot ratio have major impact on cycle time. This study attempts to find an optimal combination of batch process and single wafer process machines in furnace area. And given the same cost, an optimal combination of batch process and SWP machines can be found to reduce normal lot cycle time by 4.0~4.5% and hot lot cycle time by 6.1%~16.4%, and increase batch process capacity efficiency by 15.3%~~23.4%. The result of the study provides managers insights for the cost-effect of single wafer process machines. And the methodologies proposed can be used by practitioners to support the decision making for adopting single-wafer process machines.

碩士
國立中山大學
海洋環境及工程學系研究所
98
Taiwan semiconductor manufacturing industry ranks top in the world for the production and has a great contribution to Taiwan economics. However, the industry produces a significant amount of volatile organic compounds (VOC) into the air. According to EPA of Taiwan, the annual VOC emission amounts from the industry were approximately five thousand tons, a major stationary source of VOC emission. The EPA has implemented the air pollution control regulation for semiconductor industry, in which the VOC emission amount should be below <0.6 kg/hr or the removal efficiency should be >90% for each factory . The conventional control technologies for the VOC emissions was concentration using zeolite followed by thermal oxidation. However, the high boiling points of VOC is difficult to desorbed from zeolite and it required the water to wash the zeolite. This would reduce the removal efficiency of zeolite. This control processes have high operation cost and may produce byproducts required for further treatment. Advanced chemical oxidation process (AOP) recently has gained tremendous attention as an emerging control technology of VOC due to low treatment cost and few oxidation byproducts. The major oxidant of the technology is believed to be hydroxyl radicals, which can react organic compounds at very reaction rates. A majority of VOC emissions from the semiconductor industry are highly soluble and can be easily dissolved into water by scrubbing process. However, the wet scrubbing process can produce a significant amount of wastewater. The objective of this study was to investigate the feasibility of using wet scrubber and O3/H2O2/catalyst process on controlling the VOC emissions from the semiconductor manufacturing industry. A full scale of process of 1000 CMM flowrate was designed and built along with a semiconductor packaging facility. Results showed that major compounds of the VOC exhaust were iso-propanol, PGMEA, PGME and methyl ethyl keton. The inlet concentrations of THC significantly varied from 50 to 600 ppmv as methane. The AOP process can removed 90-95% of VOCs and the scrubbing water can be recycled and reused at least 95%. The capital cost of the system was NT20,000,000 with the annual operation cost of NT120,000 which was only 36-40% of it for the concentration using zeolite followed by thermal oxidation.

碩士
世新大學
圖文傳播暨數位出版學研究所(含碩專班)
106
Most of the preparations used for wet production of ferric chloride or cadmium iodide, today, environmental awareness, we try to use cadmium bromide as a control group of Quinn Jacobson new iron ore iron ore formula, with potassium bromide, sodium bromide , Ammonium bromide and Lithium bromide instead of cadmium bromide, adjust the torch formula, the actual shooting and measurement images in the gray guide table, compare the experimental group salt tone tone performance. Potassium bromide potassium iodide formula performance even more than the formula cadmium bromide is good, but its storage is poor, without the need for long-term storage under the premise that the wet board craft enthusiasts can adjust the use of fresh potassium bromide potassium iodide salt stained collodion to replace the environment and the human body harmful cadmium bromide micelle body.

碩士
國立中山大學
環境工程研究所
106
In this study, the application of micro/nano bubbles wet scrubber to process methyl ethyl ketone in the exhaust process of flexible copper clad lamainate was investigated. This was done in order to evaluate the removal efficiency of VOCs-MEK in the exhaust emissions from the process of processing the flexible copper clad lamainate scrubber in the micro/nano bubbles wet scrubber. The adjustment of parameters as well as the evaluation of scrubber processing VOCs-MEK efficiency, along with the understanding of the practicality of the plant, would help to increase the application of technology development, improve processing efficiency, so as to reduce the emission of volatile organic compounds in the air. The removal efficiency in micro/nano bubbles water circulation shows that with the increase of treatment time, the removal rate decreases, and the COD in the washing liquid increases, thus the removal rate cannot be sustained. In micro/nano bubbles water without recycling conditions, there is an 80% removal rate at the beginning, but the overall trend of removal efficiency still decreases, yet the removal efficiency can be maintained at more than 40%; the conductivity and removal rate have no obvious change and the pH in water the COD will increase with time. The ORP test value change will increase as the removal rate decreases. It will no longer rise to a flat level after rising to a constant value; and each parameter shows that VOCs-MEK can be increased through the adjustment of the operating parameter - intake air flow rate and removal rate. Comprehensive test results show that the non-recycling test can increase the removal rate of VOCs-MEK-containing off-gas in the micro/nano bubbles wet scrubber and maintain it at about 40 to 80%; increasing the air volume can increase the removal efficiency of this set of equipment by 7%.

Misdade wat gemik is teen kinders veroorsaak tans ‘n nasionale krisis wat geïllustreer word deur die feit dat daar ‘n toename in die mishandeling en verwaarlosing van kinders is. Al hoe meer kinders word ook wees gelaat na die afsterwe van hul biologiese ouers weens MIV/VIGS-verwante siektes. Dit bring mee dat daar ‘n geweldige toename in pleegsorgplasings in Suid-Afrika is. Welsynsorganisasies beskik egter nie oor ‘n resente opleidingsprogram wat daarop gemik is om voornemende pleegouers op pleegsorg voor te berei nie. Die doel van die studie het behels om ‘n opleidingsprogram vir voornemende pleegouers te ontwikkel, te implementeer en empiries te toets. Die doelwitte wat gestel is om die doel te bereik was om ‘n opleidingsprogram vir voornemende pleegouers te ontwikkel, die program by voornemende pleegouers te toets en om die impak van die program waar te neem deur die resultate van ‘n voor- en natoets te vergelyk. Die inhoud van die opleidingsprogram wat vir die studie ontwikkel is, is beskryf. Gevolglik is van beskrywende navorsing gebruik gemaak. Hierdie studie het berus op die volgende hipotese: Indien voornemende pleegouers hierdie opleidingsprogram deurloop het, sal die voornemende pleegouers se kennis rakende die omvang, wetlike implikasies, verwagtinge, motiewe, verantwoordelikhede en pligte ten opsigte van pleegsorg, en die profiel van die pleegkind verbeter. Die empiriese resultate van die studie het die hipotese as waar bewys.‘n Kwantitatiewe enkelstelselontwerp, is die benadering wat gevolg is. Data is ingesamel met behulp van ‘n vraelys wat tydens ‘n voor- en natoets benut is. Altesaam 53 respondente (ouer as 20 jaar) bestaande uit getroude pare en enkellopendes wat gedurende die tydperk Februarie tot Junie 2006, by die Ondersteuningsraad van Pretoria as voornemende pleegouers aangemeld het, is by die studie betrek. Die 53 respondente is in drie groepe ingedeel. Drie opleidingsessies met elk van die drie groepe is onderneem. Rothman en Thomas se model vir intervensienavorsing is benut om die opleidingsprogram vir voornemende pleegouers te ontwikkel. Die model bestaan uit ses fases, waarvan die eerste vyf fases in die studie benut is. Tydens die eerste fase is die probleem ontleed; in die tweede fase is teoretiese inligting versamel en deelnemers by die studie betrek; by die derde en vierde fases, is die opleidingsprogram tentatief ontwerp en getoets om leemtes te identifiseer. Daarna is die program volledig geïmplementeer en die impak daarvan empiries getoets. Die kwantitatiewe data (voor- en natoets) is met behulp van ‘n selfontwerpte vraelys ingesamel. Die vraelys is benut om inligting aangaande die respondente se kennis van pleegsorg te verkry. Individuele telefoniese onderhoude is een maand na afloop van die implementering van die program met die respondente gevoer om addisionele inligting te kry. Die resultate van die voor- en natoets het getoon dat die opleidingsprogram suksesvol was. Die respondente wat by die studie betrek is, het ‘n verbetering getoon ten opsigte van hul kennis van pleegsorg. Na die evaluering van die opleidingsprogram, is ‘n samevatting van die vernaamste bevindings, en gevolgtrekkings vir die ondersoek in geheel, aangebied. Aanbevelings is gemaak en is temas vir verdere navorsing geïdentifiseer.
Thesis (DPhil)--University of Pretoria, 2008.
Social Work and Criminology
unrestricted

Dissertação de Mestrado em Mecânica dos Solos e Engenharia Geotécnica apresentada à Faculdade de Ciências e Tecnologia
Reservatório Cerro da Mina é um reservatório de águas industriais, parte do complexo mineiro de Neves-Corvo, ao sul de Portugal. Impermeabilizado a montante por uma membrana de PEAD e construído aproximadamente metade em enrocamento e metade em rocha escavada, esta barragem esteve sujeita a três momentos de assentamento abruptos no aterro nos seus primeiros anos de operação. Este comportamento levantou questões acerca da natureza dos movimentos e da possibilidade de algum problema inesperado. A análise dos dados de nove extensómetros e de um inclinómetro instalados na secção de maior altura do enrocamento, juntamente com a avaliação das condições ambientais nos períodos em causa, revelaram que os deslocamentos significativos e inesperados coincidiram com períodos de intensa pluviosidade e subida no nível de água no reservatório. Tanto as deformações verticais como as horizontais apresentaram tendência de aumento acelerado sempre que um novo máximo no histórico de precipitações era registrado. O comportamento observado sugere que o aumento da humidade nos vazios do enrocamento gera uma redução significativa nos valores de sucção nos poros dos elementos rochosos, causando colapsos induzidos por molhagem no enrocamento. Além disso, os dados de observação indicam uma reduzida influência da oscilação do nível de água no reservatório na direção vertical, descartando este fator como causa principal dos assentamentos no enrocamento. As taxas de deformações verticais a longo prazo foram calculadas e apresentaram tendência similar ao previsto para este tipo de estrutura, não demonstrando sinais de problema neste sentido.
Reservatório Cerro da Mina is an industrial water reservoir part of Neves-Corvo mining compound, in the south of Portugal. Covered by an upstream impervious HDPE membrane and constructed approximately half on rockfill embankment and half on excavated rock, this dam experienced three moments of abrupt settlements on its embankments in the first years of operation. This behaviour raised concerns regarding the nature of the movements and the possibility of unanticipated problems. The analysis of the data from nine extensometers and one inclinometer installed in the highest section of the rockfill embankment, along with the assessment of the environmental conditions in the periods of interest, revealed that these significant unexpected vertical displacements coincided with periods of intense rainfall and rise in the water level in the reservoir. Both vertical and horizontal deformations of the rockfill showed a tendency of sudden increase when a new maximum in the precipitation record occurred. This represents an indication that the increase in humidity in the rockfill voids led to a significant decrease in the rock pore suction, causing wet-induced collapses in the rockfill. Additionally, the influence of the oscillation of the water level reservoir was estimated very small in the vertical direction, rejecting this factor as a major source of settlements in the rockfill. Long-term vertical deformation rates in the rockfill were calculated and presented a tendency fairly similar to what is expected for the kind of construction, showing no evidences of problems in that matter.