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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Desenvolvimento de um elemento combustível instrumentado para o reator de pesquisa IEA-R1 / Development of an instrumented fuel assembly for the IEA-R1 research reactor

Umbehaun, Pedro Ernesto 20 May 2016 (has links)
Após o aumento de potência do reator IEA-R1 de 2 MW para 5 MW observou-se um aumento da taxa de corrosão nas placas laterais de alguns elementos combustíveis e algumas dúvidas surgiram com relação ao valor de vazão utilizada nas análises termo-hidráulicas. A fim de esclarecer e medir a distribuição de vazão real pelos elementos combustíveis que compõe o núcleo do reator IEA-R1, um elemento combustível protótipo, sem material nuclear, chamado DMPV-01 (Dispositivo para Medida de Pressão e Vazão), em escala real, foi projetado e construído em alumínio. A vazão no canal entre dois elementos combustíveis é muito difícil de estimar ou ser medida. Esta vazão é muito importante no processo de resfriamento das placas laterais. Este trabalho apresenta a concepção e construção de um elemento combustível instrumentado para medir a temperatura real nestas placas laterais para melhor avaliar as condições de resfriamento do combustível. Quatorze termopares foram instalados neste elemento combustível instrumentado. Quatro termopares em cada canal lateral e quatro no canal central, além de um termopar no bocal de entrada e outro no bocal de saída do elemento. Existem três termopares para medida de temperatura do revestimento e um para a temperatura do fluido em cada canal. Três séries de experimentos, para três configurações distintas, foram realizadas com o elemento combustível instrumentado. Em dois experimentos uma caixa de alumínio foi instalada ao redor do núcleo para reduzir o escoamento transverso entre os elementos combustíveis e medir o impacto na temperatura das placas externas. Dada a tamanha quantidade de informações obtidas e sua utilidade no projeto, melhoria e capacitação na construção, montagem e fabricação de elementos combustíveis instrumentados, este projeto constitui um importante marco no estudo de núcleos de reatores de pesquisa. As soluções propostas podem ser amplamente utilizadas para outros reatores de pesquisa. / After the IEA-R1 upgrade from 2 MW to 5 MW it was observed that the corrosion rate increased in a lateral plate of one fuel element and some issues appeared concerning the flow values used in the thermal-hydraulic analysis. In order to clear it up and measure the actual flow distribution among the fuel elements composing the IEA-R1 active core, a dummy element without nuclear fuel material, called DMPV-01 (Pressure and Flow Measurement Device), full scale, was designed and manufactured in aluminum. The flow rate in the channel between two fuel assemblies is very difficult to estimate or measure. This flow rate is very important to the cooling process of the external plates. This work presents the design and construction of an instrumented fuel assembly in order to measure the actual temperature in these lateral plates. Fourteen thermocouples were installed in this instrumented fuel assembly. Four in each lateral channel, one in the inlet nozzle and one in the outlet nozzle. There are three thermocouples in each channel to measure the clad temperature and one thermocouple to measure the fluid temperature. Three series of experiments, for three different core configuration were carried out with the instrumented fuel assembly. In two experiments a box was installed around the core to reduce the cross flow between the fuel assembly and measure the impact in the temperatures of external plates. Given the amount of information generated and its utility in the design, improvement and qualification in construction, assembly and manufacturing of instrumented fuel, this project turned out to be an important landmark on the thermal-hydraulic study of research reactor cores. The proposed solutions could be useful for other research reactors.
152

Perspectiva histórica e tecnológica da calibração do túnel 2 do Sistema Cantareira de adução de água para a região metropolitana de São Paulo / Historical and technological perspective of the test for the calibration of tunnel 2 of the Cantareira water project for the metropolitan area of São Paulo

Pinheiro, Hemerson Donizete 22 March 2007 (has links)
Trabalhos de cunho historiográfco que visam resgatar a produção científica e tecnológica de um país tem auxiliado a compreender e a classificar seu nível de desenvolvimento frente a estas questões. Com este trabalho, espera-se dar início no Departamento de Hidráulica e Saneamento (SHS) da Escola de Engenharia de São Carlos, a um levantamento historiográfico da produção tecnológica e científica de seus pós-graduandos e professores. Para tanto, resgata-se um trabalho realizado entre o final da década de 1960 e início da década de 1970, pela Cátedra de Mecânica dos Fluidos (precursora do SHS), que teve como objetivo prever a vazão de água do túnel 2 do Sistema Cantareira de abastecimento de água para a região metropolitana de São Paulo. Nesta galeria foi realizado um ensaio original com circulação de ar, para o qual foram desenvolvidos métodos e técnicas a fim de verificar a vazão e auxiliar no seu dimensionamento, para garantir uma adução de 33 \'M POT.3\'/s. Mediante o levantamento, organização cronológica e análise dos documentos produzidos pelos autores do referido ensaio, resgatam-se as influências teóricas que nortearam as metodologias, as técnicas e tecnologias e analisam-se, de acordo com os registros documentais, a execução e resultados alcançados pelos ensaios. / Works that have as objective to review the scientific and technological production of a country have helped to understand and to measure its level of development regarding these questions. With this work, hopefully a historical survey of the technological and scientific production of its graduate students and teachers begins at the Departamento de Hidráulica e Saneamento (SHS) at the Escola de Engenharia de São Carlos. In this way, a work that was carried out between the end of the 1960\'s and beginning of the 1970\'s, by the chair of fluid mechanics (precursor of the SHS), which had as objective to foresee the water flow rate at tunnel 2 of the Cantareira water project for the metropolitan area of São Paulo. An original test using air circulation was carried out in the tunnel. Methods and techniques were developed in order to verify the flow rate and check its size, to guarantee 33 \'M POT.3\'/s of flow. The documents produced by the authors of the test were surveyed, organized chronologically and analyzed, seeking to infer the theoretical influences that had guided the methodologies, to describe the techniques and technologies and to analyze, in accordance with the document registers, the execution and results reached from the tests.
153

Desenvolvimento de um elemento combustível instrumentado para o reator de pesquisa IEA-R1 / Development of an instrumented fuel assembly for the IEA-R1 research reactor

Pedro Ernesto Umbehaun 20 May 2016 (has links)
Após o aumento de potência do reator IEA-R1 de 2 MW para 5 MW observou-se um aumento da taxa de corrosão nas placas laterais de alguns elementos combustíveis e algumas dúvidas surgiram com relação ao valor de vazão utilizada nas análises termo-hidráulicas. A fim de esclarecer e medir a distribuição de vazão real pelos elementos combustíveis que compõe o núcleo do reator IEA-R1, um elemento combustível protótipo, sem material nuclear, chamado DMPV-01 (Dispositivo para Medida de Pressão e Vazão), em escala real, foi projetado e construído em alumínio. A vazão no canal entre dois elementos combustíveis é muito difícil de estimar ou ser medida. Esta vazão é muito importante no processo de resfriamento das placas laterais. Este trabalho apresenta a concepção e construção de um elemento combustível instrumentado para medir a temperatura real nestas placas laterais para melhor avaliar as condições de resfriamento do combustível. Quatorze termopares foram instalados neste elemento combustível instrumentado. Quatro termopares em cada canal lateral e quatro no canal central, além de um termopar no bocal de entrada e outro no bocal de saída do elemento. Existem três termopares para medida de temperatura do revestimento e um para a temperatura do fluido em cada canal. Três séries de experimentos, para três configurações distintas, foram realizadas com o elemento combustível instrumentado. Em dois experimentos uma caixa de alumínio foi instalada ao redor do núcleo para reduzir o escoamento transverso entre os elementos combustíveis e medir o impacto na temperatura das placas externas. Dada a tamanha quantidade de informações obtidas e sua utilidade no projeto, melhoria e capacitação na construção, montagem e fabricação de elementos combustíveis instrumentados, este projeto constitui um importante marco no estudo de núcleos de reatores de pesquisa. As soluções propostas podem ser amplamente utilizadas para outros reatores de pesquisa. / After the IEA-R1 upgrade from 2 MW to 5 MW it was observed that the corrosion rate increased in a lateral plate of one fuel element and some issues appeared concerning the flow values used in the thermal-hydraulic analysis. In order to clear it up and measure the actual flow distribution among the fuel elements composing the IEA-R1 active core, a dummy element without nuclear fuel material, called DMPV-01 (Pressure and Flow Measurement Device), full scale, was designed and manufactured in aluminum. The flow rate in the channel between two fuel assemblies is very difficult to estimate or measure. This flow rate is very important to the cooling process of the external plates. This work presents the design and construction of an instrumented fuel assembly in order to measure the actual temperature in these lateral plates. Fourteen thermocouples were installed in this instrumented fuel assembly. Four in each lateral channel, one in the inlet nozzle and one in the outlet nozzle. There are three thermocouples in each channel to measure the clad temperature and one thermocouple to measure the fluid temperature. Three series of experiments, for three different core configuration were carried out with the instrumented fuel assembly. In two experiments a box was installed around the core to reduce the cross flow between the fuel assembly and measure the impact in the temperatures of external plates. Given the amount of information generated and its utility in the design, improvement and qualification in construction, assembly and manufacturing of instrumented fuel, this project turned out to be an important landmark on the thermal-hydraulic study of research reactor cores. The proposed solutions could be useful for other research reactors.
154

Assessing reservoir performance and modeling risk using real options

Singh, Harpreet 02 August 2012 (has links)
Reservoir economic performance is based upon future cash flows which can be generated from a reservoir. Future cash flows are a function of hydrocarbon volumetric flow rates which a reservoir can produce, and the market conditions. Both of these functions of future cash flows are associated with uncertainties. There is uncertainty associated in estimates of future hydrocarbon flow rates due to uncertainty in geological model, limited availability and type of data, and the complexities involved in the reservoir modeling process. The second source of uncertainty associated with future cash flows come from changing oil prices, rate of return etc., which are all functions of market dynamics. Robust integration of these two sources of uncertainty, i.e. future hydrocarbon flow rates and market dynamics, in a model to predict cash flows from a reservoir is an essential part of risk assessment, but a difficult task. Current practices to assess a reservoir’s economic performance by using Deterministic Cash Flow (DCF) methods have been unsuccessful in their predictions because of lack in parametric capability to robustly and completely incorporate these both types of uncertainties. This thesis presents a procedure which accounts for uncertainty in hydrocarbon production forecasts due to incomplete geologic information, and a novel real options methodology to assess the project economics for upstream petroleum industry. The modeling approach entails determining future hydrocarbon production rates due to incomplete geologic information with and without secondary information. The price of hydrocarbons is modeled separately, and the costs to produce them are determined based on market dynamics. A real options methodology is used to assess the effective cash flows from the reservoir, and hence, to determine the project economics. This methodology associates realistic probabilities, which are quantified using the method’s parameters, with benefits and costs. The results from this methodology are compared against the results from DCF methodology to examine if the real options methodology can identify some hidden potential of a reservoir’s performance which DCF might not be able to uncover. This methodology is then applied to various case studies and strategies for planning and decision making. / text
155

Real time detectionof airborne fungal spores and investigations into their dynamics in indoor air

Kanaani, Hussein January 2009 (has links)
Concern regarding the health effects of indoor air quality has grown in recent years, due to the increased prevalence of many diseases, as well as the fact that many people now spend most of their time indoors. While numerous studies have reported on the dynamics of aerosols indoors, the dynamics of bioaerosols in indoor environments are still poorly understood and very few studies have focused on fungal spore dynamics in indoor environments. Consequently, this work investigated the dynamics of fungal spores in indoor air, including fungal spore release and deposition, as well as investigating the mechanisms involved in the fungal spore fragmentation process. In relation to the investigation of fungal spore dynamics, it was found that the deposition rates of the bioaerosols (fungal propagules) were in the same range as the deposition rates of nonbiological particles and that they were a function of their aerodynamic diameters. It was also found that fungal particle deposition rates increased with increasing ventilation rates. These results (which are reported for the first time) are important for developing an understanding of the dynamics of fungal spores in the air. In relation to the process of fungal spore fragmentation, important information was generated concerning the airborne dynamics of the spores, as well as the part/s of the fungi which undergo fragmentation. The results obtained from these investigations into the dynamics of fungal propagules in indoor air significantly advance knowledge about the fate of fungal propagules in indoor air, as well as their deposition in the respiratory tract. The need to develop an advanced, real-time method for monitoring bioaerosols has become increasingly important in recent years, particularly as a result of the increased threat from biological weapons and bioterrorism. However, to date, the Ultraviolet Aerodynamic Particle Sizer (UVAPS, Model 3312, TSI, St Paul, MN) is the only commercially available instrument capable of monitoring and measuring viable airborne micro-organisms in real-time. Therefore (for the first time), this work also investigated the ability of the UVAPS to measure and characterise fungal spores in indoor air. The UVAPS was found to be sufficiently sensitive for detecting and measuring fungal propagules. Based on fungal spore size distributions, together with fluorescent percentages and intensities, it was also found to be capable of discriminating between two fungal spore species, under controlled laboratory conditions. In the field, however, it would not be possible to use the UVAPS to differentiate between different fungal spore species because the different micro-organisms present in the air may not only vary in age, but may have also been subjected to different environmental conditions. In addition, while the real-time UVAPS was found to be a good tool for the investigation of fungal particles under controlled conditions, it was not found to be selective for bioaerosols only (as per design specifications). In conclusion, the UVAPS is not recommended for use in the direct measurement of airborne viable bioaerosols in the field, including fungal particles, and further investigations into the nature of the micro-organisms, the UVAPS itself and/or its use in conjunction with other conventional biosamplers, are necessary in order to obtain more realistic results. Overall, the results obtained from this work on airborne fungal particle dynamics will contribute towards improving the detection capabilities of the UVAPS, so that it is capable of selectively monitoring and measuring bioaerosols, for which it was originally designed. This work will assist in finding and/or improving other technologies capable of the real-time monitoring of bioaerosols. The knowledge obtained from this work will also be of benefit in various other bioaerosol applications, such as understanding the transport of bioaerosols indoors.
156

Spårämnestillsatsers påverkan på biogasproduktionen vid anaerob rötning av avloppsslam : Behovet av spårämnen vid slamrötning på Karlstads reningsverk / The influence of trace element addition on the biogas production from anaerobic digestion of sewage sludge : The need for trace elements in the digestion of sewage sludge at Karlstads wastewater treatment plant

Fokkema, Maaike January 2018 (has links)
Sverige har som mål att endast använda fossilfria bränslen inom fordonsflottan till år 2030. Ett av dessa fossilfria bränslen är biogas som bland annat produceras på Karlstads reningsverk, Sjöstadsverket. Sjöstadsverket planerar att bygga ut sin slammottagningsstation för att kunna ta emot mer slam. I samband med detta finns det ett intresse av att undersöka effektiviseringsmöjligheter inom biogasproduktionen. Ett vanligt förekommande sätt att öka biogasproduktionen är genom tillsatser av olika spårämnen. I detta arbete har därför tillsatser av spårämnena järn, kobolt, nickel och magnesium undersökts genom termofila småskaliga rötningsförsök i satsreaktorer. Tillsatserna har även undersökts i kombination med det komplexbildande ämnet EDTA för att undersöka om den biologiska tillgängligheten påverkar vid rötning av avloppsslam. Förutom rötningsförsök har även en korrelationsanalys genomförts där olika faktorer som kan påverka biogasproduktionen undersökts för år 2017. Resultaten av rötningsförsöken visar att inga tillsatser av järn, magnesium, nickel eller kobolt kommer öka biogasproduktionen vid Sjöstadsverket. Istället har biogasproduktionen hämmats vid två av tre rötningsförsök. Dessa resultat indikerar att organismerna i rötningsanläggningen på Sjöstadsverket inte har någon brist på spårämnen. Inte heller tillsatser av EDTA ökade biogasproduktionen vilket visar att det inte heller finns brist på biologiskt tillgängliga spårämnen. Resultaten från rötningsförsöken styrks av korrelationsanalysen eftersom det inte heller finns några tecken på korrelation mellan biogasproduktion och de nämnda spårämnena. Resultaten av korrelationsanalysen visar att pH ut ur rötningsanläggningen kan ha en negativ inverkan på biogasproduktionen vid Sjöstadsverket. Resultaten indikerar att pH blir för högt i anläggningen, något som även påvisats vid rötningsförsöken. Ett högre flöde in i anläggningen kan sänka pH-värdet enligt vidare korrelationsstudier. Detta har även kunnat påvisas vid rötningsförsöken där pH blev lägre vid en kortare uppehållstid. Eftersom Sjöstadsverket baserar sin uppehållstid på en stabil volym i rötkamrarna bör det alltså vara möjligt att öka biogasproduktionen genom att öka flödet in i rötningsanläggningen, vilket kommer ske när den nya slammottagningsstationen sätts i bruk. Eftersom dessa slutsatser främst är baserade på korrelationer rekommenderas vidare studier där pH-värdets och uppehållstidens inverkan på biogasproduktionen vid Sjöstadsverket undersöks närmare. / The Swedish government has set a national goal to have no vehicles running on fossil fuels in year 2030. One of the fuels that can replace the fossil fuels of today is biogas. The biggest wastewater treatment plant in Karlstad, called Sjöstadsverket, is already producing biogas and is expanding to receive more sludge in the future. Because of this, Sjöstadsverket wants to investigate the possibility of a more effective biogas production. A common way to improve biogas production is trace element additives. Therefor the addition of cobalt, nickel, iron and magnesium has been investigated through small scale thermophilic anaerobic digestion trials in batch reactors. The trace elements have also been added in combination with EDTA to investigate the bioavailability of the trace elements. In addition to these experiments a correlation analysis was performed where different factors that might influence the biogas production were investigated for year 2017. The results from the digestion trials prove that no addition of iron, magnesium, cobalt or nickel will increase the biogas production. Instead, the biogas production was inhibited during two out of three experiments. These results indicate that the organisms in the digester at Sjöstadsverket already have a sufficient amount of trace elements. The addition of EDTA did not increase the biogas production either which indicates that the trace elements also are bioavailable to a sufficient extent. The results from the digestion trials are validated by the correlation analysis because no correlation could be found between the biogas production and the investigated trace elements. The results from the correlation analysis show that the pH-level affects the biogas production negatively. The results indicate that the pH-level is to high, something that was also observed during the digestion trials. A higher flow rate into the digesters could lower the pH-levels according to further correlation studies. This has also been observed during the digestion trials where a shorter retention time lowered the pH-levels. Because Sjöstadsverket bases their retention time on a stable volume in the digesters, it could be possible for them to increase the biogas production by increasing the flow rates, which will happen when they start receiving more sludge. Because these conclusions are mainly based on correlations, further studies of the influence of pH-levels and retention times on the biogas production at Sjöstadsverket are recommended.
157

Perspectiva histórica e tecnológica da calibração do túnel 2 do Sistema Cantareira de adução de água para a região metropolitana de São Paulo / Historical and technological perspective of the test for the calibration of tunnel 2 of the Cantareira water project for the metropolitan area of São Paulo

Hemerson Donizete Pinheiro 22 March 2007 (has links)
Trabalhos de cunho historiográfco que visam resgatar a produção científica e tecnológica de um país tem auxiliado a compreender e a classificar seu nível de desenvolvimento frente a estas questões. Com este trabalho, espera-se dar início no Departamento de Hidráulica e Saneamento (SHS) da Escola de Engenharia de São Carlos, a um levantamento historiográfico da produção tecnológica e científica de seus pós-graduandos e professores. Para tanto, resgata-se um trabalho realizado entre o final da década de 1960 e início da década de 1970, pela Cátedra de Mecânica dos Fluidos (precursora do SHS), que teve como objetivo prever a vazão de água do túnel 2 do Sistema Cantareira de abastecimento de água para a região metropolitana de São Paulo. Nesta galeria foi realizado um ensaio original com circulação de ar, para o qual foram desenvolvidos métodos e técnicas a fim de verificar a vazão e auxiliar no seu dimensionamento, para garantir uma adução de 33 \'M POT.3\'/s. Mediante o levantamento, organização cronológica e análise dos documentos produzidos pelos autores do referido ensaio, resgatam-se as influências teóricas que nortearam as metodologias, as técnicas e tecnologias e analisam-se, de acordo com os registros documentais, a execução e resultados alcançados pelos ensaios. / Works that have as objective to review the scientific and technological production of a country have helped to understand and to measure its level of development regarding these questions. With this work, hopefully a historical survey of the technological and scientific production of its graduate students and teachers begins at the Departamento de Hidráulica e Saneamento (SHS) at the Escola de Engenharia de São Carlos. In this way, a work that was carried out between the end of the 1960\'s and beginning of the 1970\'s, by the chair of fluid mechanics (precursor of the SHS), which had as objective to foresee the water flow rate at tunnel 2 of the Cantareira water project for the metropolitan area of São Paulo. An original test using air circulation was carried out in the tunnel. Methods and techniques were developed in order to verify the flow rate and check its size, to guarantee 33 \'M POT.3\'/s of flow. The documents produced by the authors of the test were surveyed, organized chronologically and analyzed, seeking to infer the theoretical influences that had guided the methodologies, to describe the techniques and technologies and to analyze, in accordance with the document registers, the execution and results reached from the tests.
158

Citlivostní analýza metody tlak-čas na nepřesnosti měření / Sensitivity analysis of pressure-time method on measurement uncertainty

Červinková, Kateřina January 2019 (has links)
The pressure-time method is one of two methods of measuring the flow rate on large hydraulic structures applicable to IEC 60041, which is based on the temporal integration of the measured pressure difference and the formation of a water hammer in a closed pipe. The aim of this master thesis is to perform a literature review of this method and to evaluate the flow rate of the measured data. Furthermore, the thesis deals with determination of the sensitivity of the evaluated flow rate to the weights of individual pressure sensors and to numerical modifying of the measured pressures. The first part is made using MS Excel. The flow rate is always evaluates with only one pressure sensor and it is compared with the original flow rate. There is research, how absence of the sensor has an impact on the evaluated flow rate. In the second part of the determination of the sensitivity of the evaluated flow rate, various encroachment (signal smoothing, noise, time delay, frequency band removal) are performed of measured pressure signal in Matlab. Various surrounding influences or sensors failures are simulated.
159

Vytvoření hydrologického modelu pro odvození maximálních odtoků z malých povodí / Creating a Hydrological Model to Determine Maximum Runoff from a Small Catchments

Hakl, Petr January 2020 (has links)
The aim of the thesis is to set a hydrology model based on existed methodology DesQ-MaxQ, which comes from "Designing flows from a very small catchments" established in 1989. The model is able to set a nearest meteorology station and his 24-hours rainfall depths for periods of repetition 2,5,10,20,50 and 100 years. Substitute rainfall depths are set by "reduction of 24-hours rainfall depths" methodology. According to hydraulic and hydrology conditions of catchment, duration of the critical rains for each period of repetition are set also peak flow rates and total runoffs from the catchment. Application can work in two modes - "one slope" and "two slopes". The second option also includes calculation of design duration for the model catchment and superposition of hydrograph. Application RainRunoff was develop in C# programming language with graphic user interface and option to exports hydrographs.
160

Napájecí zdroj elektrostatického odlučovače / Power supply of electrostatic separator

Broďák, Kamil January 2015 (has links)
The diploma thesis focuses on the problems of electric power precipitators. Due to their current dominant position, the work concentrates on the sources of single phase transformers operating at the frequency of 50 Hz controlled by thyristors. The first part describes the electrostatic precipitator and its principle. This is followed by a brief insight into the proposal for an electrostatic precipitator. The work also explains the high voltage source that is divided into a transformer with a rectifier and into a control box with power circuits and control circuits that provide the power supplied by a transformer. The work also offers an explanation of the HV source system that operates at different conditions. The last part suggests a proposal for cooling cabinet including thyristors, for power line control box resources, for a supply line and a line to the transformer.

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