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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.
1

Biodiesel de dendê em trator agrícola: desempenho em função do tempo de armazenamento e da proporção de mistura na operação de preparo do solo

Camara, Felipe Thomaz da [UNESP] 25 September 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-09-25Bitstream added on 2014-06-13T20:21:42Z : No. of bitstreams: 1 camara_ft_dr_jabo.pdf: 548163 bytes, checksum: a7f77b0a81b4b0e6e9ac1c242bc53422 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Funep / Biodiesel is a renewable fuel, biodegradable and produced from vegetable oil or from animal fat through transesterification. The viability of this product as a source of alternative energy depends on various factors, among which the mixture proportion and the stability during storage time stand out. This is because the availability of the raw material is seasonal and varies in accordance with the harvests of different cultures. The objective of the present work was to evaluate the operational performance of an agricultural tractor working with palm oil biodiesel while performing the operation of tillage with a chisel plow, also opacity, the density of the fuel and the outflow from the filling pump were studied regarding storage time and biodiesel/diesel mixture proportion. The experiment was conducted in the Department of Rural Engineering at UNESP, Jaboticabal, Brazil, in partnership with LADETEL/USP-Ribeirão Preto. Storage time was with new fuel (soon after production), three months and six months, and the percentage proportions used for biodiesel + diesel were B0 (0+100), B5 (5+95), B50 (50+50) e B100 (100+0). When comparing the treatments, we evaluated the fuel consumption, the real velocity of displacement, the sliding of the wheels, the strength of the traction bar, the fuel density, the outflow from the filling pump and the opacity of the fuel smoke. The results show an increase in consumption specific to a mixture starting from 25% biodiesel, although the storage time did not affect consumption. In relation to the opacity of smoke, there was a reduction, even with only 5% biodiesel in the mixture, again with the storage time having no influence.
2

Redução do combustível primário e dos gases poluentes na máquina primária de um grupo gerador à diesel com injeção de hidrogênio

Triantafilu, Patrique Borchhardt 16 October 2018 (has links)
Submitted by Cristiane Chim (cristiane.chim@ucpel.edu.br) on 2018-12-03T10:42:25Z No. of bitstreams: 1 Patrique.pdf: 3054329 bytes, checksum: aa18d3c8b8679fb997de53a96a88b58a (MD5) / Made available in DSpace on 2018-12-03T10:42:25Z (GMT). No. of bitstreams: 1 Patrique.pdf: 3054329 bytes, checksum: aa18d3c8b8679fb997de53a96a88b58a (MD5) Previous issue date: 2018-10-16 / This work aims to evaluate the injection of HHO gas, from a hydrogen generator (electrolyser), into a diesel generator set. After mixing the HHO gas together with the diesel oil, a compression in exhaust gases, exhaust temperature, carbon monoxide emission, carbon dioxide and primary engine fuel consumption. The results allowed to evaluate that, when the engine was fed with diesel and hydrogen, there was a better performance in relation to the burning of fuel, when compared to a feed only with the primary fuel. At constant rated speed, the results allowed us to conclude that the engine consumes a smaller amount of diesel fuel and generating less pollutant gases (monoxide and carbon dioxide) using the HHO gas injection. / Este trabalho tem por objetivo avaliar a injeção de gás HHO, proveniente de um gerador de hidrogênio (eletrolisador), em um grupo gerador à diesel. Após a mistura do gás HHO, juntamente com o óleo diesel, foram verificados e comparados nos gases de exaustão, a temperatura do escape, emissão de monóxido de carbono, dióxido de carbono e consumo de combustível primário do motor. Os resultados encontrados permitiram avaliar que, quando o motor foi alimentado com diesel e hidrogênio, houve melhor desempenho, em relação à queima de combustível, se comparado a uma alimentação apenas com o combustível primário. Com velocidade nominal constante, os resultados permitiram concluir que o motor consome menor quantidade de óleo diesel e gerando menos quantidade de gases poluentes (monóxido e dióxido de carbono) usando a injeção de gás HHO.
3

Desempenho de grupo motor gerador alimentado com misturas de óleo residual de frituras e diesel sob cargas variadas

Almeida, Antônio Fabrício de 29 February 2016 (has links)
Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2016-11-18T15:46:08Z No. of bitstreams: 1 BlakeCDM_TESE.pdf: 4892316 bytes, checksum: 86d0db1f3948e83dab7334504ce8a41f (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-01-24T14:47:05Z (GMT) No. of bitstreams: 1 BlakeCDM_TESE.pdf: 4892316 bytes, checksum: 86d0db1f3948e83dab7334504ce8a41f (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-02-15T15:00:01Z (GMT) No. of bitstreams: 1 BlakeCDM_TESE.pdf: 4892316 bytes, checksum: 86d0db1f3948e83dab7334504ce8a41f (MD5) / Made available in DSpace on 2017-03-21T15:06:41Z (GMT). No. of bitstreams: 1 BlakeCDM_TESE.pdf: 4892316 bytes, checksum: 86d0db1f3948e83dab7334504ce8a41f (MD5) Previous issue date: 2016-02-29 / The residual oil frying (ORF), when disposed of incorrectly, cause negative impacts on the environment. However, its use as biofuel, generates great benefits of social, economic and environmental order. The objective of this study was to evaluate the performance of a group cycle diesel engine-generator powered by diesel and mineral diesel blends with residual oil frying. The trials were conducted in machines Instrumentation Laboratory and Agricultural Mechanization (Limma) of the Federal Rural University of the Semi-Arid (UFERSA) in Mossoró-RN, using a completely randomized design in factorial 4 x 5, with four replications. The treatments were diesel (DI) of oil and mixtures of diesel and residual oil frying (ORF) in the proportions: 50% DI and 50% ORF; DI 75% and 25% ORF; DI 90% and 10% ORF; 100% DI. The resistive loads used were 3, 6, 9, 12 and 15 kW. The engine oil temperature remains within the recommended operating range (85-95 ° C), indicating no lubricating oil contamination. All mixtures ORF had lower values for the exhaust temperature to the commercial diesel. The lower values of specific fuel consumption (EC) were obtained with higher loads, particularly at loads of 12 and 15 kW. The ORF25 mixture was the one with the lowest power generated and the EC farther diesel for all applied loads. Among the binary mixtures, ORF presented SE 10 similar to diesel in loads of 12 and 15 kW and the ORF50, the loads of 3, 9 and 12 kW; demonstrating that such mixing proportions, the ORF can replace mineral diesel / O óleo residual de fritura (ORF), quando descartado de maneira incorreta, causa impactos negativos ao meio ambiente. Todavia, a sua utilização como biocombustível gera grandes benefícios de ordem social, econômica e ambiental. Objetivou-se com este trabalho avaliar o desempenho de um grupo motor-gerador de ciclo diesel, alimentado com diesel mineral e misturas de diesel com óleo residual de frituras. Os ensaios foram conduzidos no Laboratório de Instrumentação de Máquinas e Mecanização Agrícola (LIMMA) da Universidade Federal Rural do Semi-Árido (UFERSA), em Mossoró-RN, utilizando delineamento experimental inteiramente casualizado, em esquema fatorial 4 x 5, com quatro repetições. Os tratamentos utilizados foram o óleo diesel mineral (DI) e misturas de diesel e óleo residual de fritura (ORF) nas proporções: 50% DI e 50% ORF; 75% DI e 25% ORF; 90% DI e 10% ORF; 100% DI. As cargas resistivas aplicadas foram de 3, 6, 9, 12 e 15 kW. A temperatura do óleo do motor se manteve dentro da faixa de trabalho recomendada (85-95 °C), indicativo de que não houve contaminação do óleo lubrificante. Todas as misturas de ORF apresentaram valores inferiores para temperatura de escapamento em relação ao diesel comercial. Os menores valores de consumo específico (CE) foram obtidos com as maiores cargas, sobretudo nas cargas de 12 e 15 kW. A mistura ORF25 foi a que apresentou a menor potência gerada e o CE mais distante do diesel para todas as cargas aplicadas. Dentre as misturas binárias, a ORF10 apresentou CE semelhante ao do diesel nas cargas de 12 e 15 kW, e a ORF50, nas cargas de 3, 9 e 12 kW; demonstrando que, nessas proporções de mistura, o ORF pode substituir o óleo diesel mineral / 2016-11-14
4

Biodiesel de dendê em trator agrícola: desempenho em função do tempo de armazenamento e da proporção de mistura na operação de preparo do solo /

Camara, Felipe Thomaz da. January 2009 (has links)
Orientador: Afonso Lopes / Banca: Wilson José Oliveira de Souza / Banca: Carlos Alberto Alves de Oliveira / Banca: Newton La Scala Junior / Banca: Carlos Eduardo Angeli Furlani / Resumo:Biodiesel é um combustível renovável, biodegradável e produzido a partir de óleo vegetal ou de gordura animal por meio de transesterificação. A viabilidade desse produto como fonte alternativa de energia depende de vários fatores, entre os quais se destacam a proporção de mistura e a estabilidade durante o período de armazenamento, uma vez que a disponibilidade de matéria-prima é sazonal e varia de acordo com a safra de cada cultura. O presente trabalho teve como objetivo avaliar o desempenho operacional realizando a operação de preparo do solo com escarificador e a opacidade da fumaça de um trator agrícola funcionando com biodiesel de dendê, a densidade do combustível e a vazão da bomba de abastecimento, cujos fatores estudados foram o tempo de armazenamento e a proporção de mistura biodiesel/diesel. O experimento foi conduzido no Departamento de Engenharia Rural, da UNESPJaboticabal, em parceria com o LADETEL/USP-Ribeirão Preto. O tempo de armazenamento foi combustível novo (logo após ser produzido), três e seis meses, e as proporções percentuais de biodiesel + diesel foram B0 (0+100), B5 (5+95), B50 (50+50) e B100 (100+0). Para comparar os tratamentos, foram avaliados o consumo de combustível, a força de tração na barra, a velocidade real de deslocamento, a patinagem das rodas, a potência na barra de tração, a densidade do combustível, a vazão da bomba de abastecimento e a opacidade da fumaça de combustão. Os resultados evidenciaram aumento no consumo específico a partir da mistura com 25% de biodiesel, entretanto o tempo de armazenamento não influenciou no consumo. Com relação a opacidade da fumaça, houve redução, mesmo com apenas 5% de biodiesel na mistura, com o tempo de armazenamento não influenciando. / Abstract: Biodiesel is a renewable fuel, biodegradable and produced from vegetable oil or from animal fat through transesterification. The viability of this product as a source of alternative energy depends on various factors, among which the mixture proportion and the stability during storage time stand out. This is because the availability of the raw material is seasonal and varies in accordance with the harvests of different cultures. The objective of the present work was to evaluate the operational performance of an agricultural tractor working with palm oil biodiesel while performing the operation of tillage with a chisel plow, also opacity, the density of the fuel and the outflow from the filling pump were studied regarding storage time and biodiesel/diesel mixture proportion. The experiment was conducted in the Department of Rural Engineering at UNESP, Jaboticabal, Brazil, in partnership with LADETEL/USP-Ribeirão Preto. Storage time was with new fuel (soon after production), three months and six months, and the percentage proportions used for biodiesel + diesel were B0 (0+100), B5 (5+95), B50 (50+50) e B100 (100+0). When comparing the treatments, we evaluated the fuel consumption, the real velocity of displacement, the sliding of the wheels, the strength of the traction bar, the fuel density, the outflow from the filling pump and the opacity of the fuel smoke. The results show an increase in consumption specific to a mixture starting from 25% biodiesel, although the storage time did not affect consumption. In relation to the opacity of smoke, there was a reduction, even with only 5% biodiesel in the mixture, again with the storage time having no influence. / Doutor
5

Assessment and Expansion of Laboratory-Based Testing of Biomass Cookstoves

Quist, Cameron M. 29 July 2021 (has links)
Biomass cookstoves are a significant source of various pollutants, such as CO2, CO, and particulate matter (PM). To mitigate the issues surrounding cookstoves, significant research has been undertaken on improved cookstoves (ICS). This research can be performed in a laboratory setting, in the field, or a combination of both. This work concentrates on the purely laboratory testing. Laboratory testing has both advantages and disadvantages when compared to field testing (e.g. decreased cost and increased consistency). However, field applications are variable, environments can be significantly different (for example wind and ambient temperature can be very different in the field vs. a controlled lab environment) and the personal preferences of the users of the cookstove can also be difficult to predict when only using laboratory testing. It is typically preferable to narrow down the possible cookstove choices by using laboratory results before heading to the field. This work concentrated on assessing the limitations of laboratory testing of cookstoves as presently constituted, as well as finding new ways to improve and expand upon the testing methodologies. Sources of error during testing was considered, leading to recommendations on how to adjust testing to decrease that error. Of note, it was found that higher thermal efficiencies led to increased propagated errors, which complicates the comparison of this efficiency among cookstoves. Additionally, a method for estimating the transient thermal efficiency was developed. Further, the effects of changing some of the key testing parameters were explored and the results showed that the overall thermal efficiency was minimally affected by parameter variations within the WBT or ISO 19867-1 guidelines. Finally, two methods were explored and compared for finding kinetic parameters associated with transforming food from the uncooked state to the cooked state. It was found that physical testing was more effective for samples that started in a harder physical state, whereas DSC testing was more effective with samples that had lower water content. This analysis was done with the intention of using transformation kinetics in future applications of cookstove models so that researchers could gain additional insights into which stoves may be best for their target market.
6

Redução do consumo específico de energia elétrica total no processo de fusão em um forno elétrico a arco /

Santos, Hachiley Polly de Castro January 2019 (has links)
Orientador: Pedro Magalhães Sobrinho / Resumo: O aço é um dos materiais mais utilizados em todo o mundo, é possível ser 100% reciclado, obtendo novo aço sem perda de qualidade e quantas vezes for necessário. O setor siderúrgico é o maior consumidor de energia final destinado a indústria. Para produção do aço existem diversas alternativas possíveis. Neste trabalho é destacada a do forno elétrico a arco, a mais eficiente em termos de energia consumida e a única a qual pode-se utilizar como matéria-prima até 100% de material reciclado. Sendo o aço uma commodity, uma mercadoria básica facilmente intercambiável e utilizada como insumo para produção de outros produtos, tem seu preço regulado pelo mercado e trabalhos em eficiência energética são essenciais para a competitividade das empresas. O presente trabalho visa elaborar sugestões de métodos e tecnologias que possibilitem a redução do consumo específico de energia elétrica em kWh/t (quilowatt hora por tonelada de aço) para o processo de fusão do aço de um forno elétrico a arco, localizado na região do Vale do Paraíba. A metodologia empregada foi a pesquisa-ação, tendo um forno elétrico a arco real, disponível para estudos e captura de dados. As soluções encontradas estão desde técnicas operacionais de produção, até tecnologias em reaproveitamento de gases de exaustão, utilizados para o pré-aquecimento de sucata. Como resultado da pesquisa, obteve-se um conjunto de possibilidades tecnológicas com ganhos de até 143 kWh/t, o que representa cerca de 34% de redução no consumo es... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Steel is one of the most widely used materials worldwide, and it is possible to recycle 100% of it so as to generate new steels without quality loss and as many times as needed, however, the steel sector is the largest final energy consumer. There are several possible routes for steel production, but the Electric Arc Furnace has been selected for the present work due to being the most efficient in terms of energy consumption and it is the only one that can use up to 100% of recycled matter as raw material. As steel is a commodity, a basic goods easily interchangeable and used as input for the production of other products, its price is set by the market and energy efficiency studies are essential for the competitiveness of companies. The present work aims to elaborate suggestions of methods and technologies that allow the reduction of the specific electric energy consumption in kWh/t (kilowatt hour per ton of steel) by the steel melting process of an electric arc furnace located in the region of the Paraíba Valley. The methodology used was the action research, having an electric arc furnace, available for studies and data capture. The identified solutions range from operational production techniques to exhaust gas recovery technologies for scrap preheating. As a result, a set of technological possibilities with savings of up to 143 kWh/t have been obtained, which represents about 34% reduction in specific electric energy consumption by taking into account an average consumptio... (Complete abstract click electronic access below) / Mestre
7

Expansion of Natural Killer (NK-92) cells and Jurkat cells for Cell therapy / Expansion Av Naturliga Mördarceller (Nk-92) Och Jurkat celler för Cellterapi

Haruna, Nana Firdausi Garba January 2024 (has links)
Natural Killer (NK) cellterapi är en lovande kandidat för cancerbehandling på grund av dess förmåga att känna igen och döda cancerceller. Adoptiv överföring av expanderade autologa eller allogena NK-celler har visat sig förbättra patientresultaten, särskilt i fall av akut myeloid leukemi (AML) efter stamcellstransplantation. En stor utmaning förknippad med NK-cellterapi är dock att få en tillräcklig mängd NK-celler för att uppnå meningsfulla terapeutiska resultat. Nuvarande metoder för att expandera NK-celler innebär ofta att T-celler avlägsnas från blodet, eftersom T-celler utgör över 50 % av blodets cellpopulation, medan NK-celler endast utgör cirka 10 %. Strategin för att ta bort T-celler involverar vanligtvis användningen av immunomagnetiska metoder, som kräver utbildad personal, är dyra och kräver god tillverkningssed (GMP) för att säkerställa metodens giltighet. Detta projekt syftade till att ta itu med denna fråga genom att etablera ett samodlingssystem mellan NK- och T-celler för att fungera som en modell för NK-expansion från patientens blod, vilket skulle kunna förbättra effektiviteten av cancerbehandling. Projektet syftade också till att undersöka det metaboliska beteendet (skillnader i näringsbehov och biprodukttolerans) mellan de två celltyperna. De två första experimenten med Jurkat gjordes med användning av en modifierad DMEM/RPMI och RPMI 1640-mediet under varierande glukos- och glutaminmålförhållanden. Resultatet från dessa två experiment visar att det modifierade DMEM/RPMI-mediet stödjer tillväxten av Jurkat-celler. Dessutom var produktionen av biprodukter inklusive laktat och ammoniak lägre i detta medium. Emellertid var glukos och glutamin avgörande för Jurkat-celltillväxt eftersom uppenbar konsumtion observerades under odlingsperioden. Det tredje experimentet syftade till att bedöma den negativa/reducerande effekten av glukos- och glutamintillstånd på Jurkat-celler. Resultaten från detta experiment applicerades sedan på NK-92-cellexpansion (fjärde experimentet). Det femte experimentet involverade samodling av båda celltyperna, med början med ett förhållande på 10% NK-celler till 90% Jurkat-celler, en ny celldiameterbaserad distributionsmetod användes för att förutsäga procentandelen NK-92-celler under samodlingen. Från dag 3 till dag 4 var det en ökning av andelen NK-celler, särskilt inom cellstorleksintervallet där de vanligtvis förekommer (17,4 µm). NK-cellerna utökades från 10 % på dag 0 till 52 % (i tillstånd med 2 mM glukos, 2 mM glutamin) på dag 3 och 45 % i tillstånd med 2 mM (glukos), 0,15 mM glutamin på dag 2. Sammantaget uppnådde denna studie framgångsrikt projektets mål att utveckla en samodlingsmodell genom att studera de enskilda cellinjernas metaboliska beteende. Ytterligare studier behövs för att undersöka effekterna av Interleukin 2 (IL-2) som produceras av Jurkat-celler på NK-celler. Dessutom skulle experiment med fler glukos- och glutaminmålkoncentrationer under längre odlingsperioder erbjuda en mer omfattande förståelse av samodlingssystemet, inklusive dess långsiktiga livskraft och celltillväxten av dessa cellinjer. / Natural Killer (NK) cell therapy is a promising candidate for cancer treatment due to its ability to recognize and kill cancer cells. The adoptive transfer of expanded autologous or allogenic NK cells has shown to improve patient outcomes, especially in cases of Acute Myeloid Leukemia (AML) following stem cell transplantation. However, a major challenge associated with NK cell therapy is obtaining a sufficient amount of NK cells to achieve meaningful therapeutic outcomes. Current methods for expanding NK cells often involve the removal of T cells from the blood, as T cells constitute over 50% of the blood's cell population, while NK cells make up only about 10%. The strategy to remove T cells typically involves the use of immunomagnetic beads, which require trained personnel, are expensive, and necessitate good manufacturing practices (GMP) to ensure the method's validity. This project aimed to address this issue by establishing a coculture system between NK and T cells to serve as a model for NK expansion from the patient blood which could improve the effectiveness of cancer treatment. The project also aimed at investigating the metabolic behavior (differences in nutrient demands and byproduct tolerance) between the two cell types. The first two experiment with Jurkat was done using a modified DMEM/RPMI and the RPMI 1640 media under varying glucose and glutamine target conditions. The result from these two experiments shows that the modified DMEM/RPMI media support the growth of Jurkat cells. In addition, the production of byproducts including lactate and ammonia were lower in this media. However, glucose and glutamine were crucial for Jurkat cells growth as evident consumption was observed during the culture period. The third experiment aimed to assess the negative/reducing impact of glucose and glutamine conditions on Jurkat cells. The findings from this experiment were then applied to NK-92 cells expansion (fourth experiment). The fifth experiment involved coculturing both cell types, starting with a ratio of 10% NK cells to 90% Jurkat cells, a new cell diameter based distribution method was used to predict the percentage of NK-92 cells during the coculture. From day 3 to day 4, there was an increase in the percentage of NK cells, particularly within the cell size range where they typically occur (17,4 µm). The NK cells were expanded from 10% on day 0 to 52% (in condition with 2mM glucose, 2mM glutamine) on day 3 and 45% in condition with 2mM(glucose), 0,15mM glutamine on day 2. Overall, this study successfully achieved the project's aim of developing a coculture model through studying the metabolic behavior of the individual cell lines. However, further studies are needed to investigate the effects of Interleukin 2 (IL-2) produced by Jurkat cells on NK cells. Moreover, conducting experiments with more glucose and glutamine targets concentrations over extended culture periods would offer a more comprehensive understanding of the coculture system, including its long-term viability and the cell growth of these cell lines.

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