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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.
101

Development of a Performance Index for Stormwater Pipeline Infrastructure

Bhimanadhuni, Sowmya 28 July 2015 (has links)
With new government regulations and emerging knowledge of the risk to the environment posed by the failure of stormwater pipelines, stormwater infrastructure asset management is becoming increasingly important in the U.S. An essential aspect of asset management practice is the accurate performance assessment of one's assets. This paper presents a weighted factor framework to determine the performance of stormwater pipes. This paper prepares a list of 50 parameters affecting the performance of stormwater pipelines; the list is based on a review of the literature, existing asset management plans, and feedback from utilities. This list is broken down into essential and preferential parameters. Indeed, not all utilities necessarily possess sufficient resources to collect such a large set of parameters. This study also develops a three-level hierarchical structure of the degradation of stormwater pipeline infrastructure. The structure consists of five failure modules and the essential parameters only. On the basis of the survey results gathered from 10 utilities across the EPA regions, the study combines the essential parameters into a performance index. The index is a scale of 1 to 5, similar to the National Association of Sewer Service Companies' Pipeline Assessment and Certification Program grading system. Grade 1 implies excellent condition and Grade 5 implies collapse is imminent. / Master of Science
102

Modelling of an industrial naphtha isomerization reactor and development and assessment of a new isomerization process

Ahmed, A.M., Jarullah, A.T., Abed, F.M., Mujtaba, Iqbal 30 June 2018 (has links)
Yes / Naphtha isomerization is an important issue in petroleum industries and it has to be a simple and cost effective technology for producing clean fuel with high gasoline octane number. In this work, based on real industrial data, a detailed process model is developed for an existing naphtha isomerization reactor of Baiji North Refinery (BNR) of Iraq which involves estimation of the kinetic parameters of the reactor. The optimal values of the kinetic parameters are estimated via minimizing the sum of squared errors between the predicted and the experimental data of BNR. Finally, a new isomerization process (named as AJAM process) is proposed and using the reactor model developed earlier, the reactor condition is optimized which maximizes the yield and research octane number (RON) of the reactor.
103

Attenuation of greenhouse gas emissions by means of methane biofiltration optimization of the operating parameters / Atténuation des émissions de gaz à effet de serre par biofiltration du méthane : optimisation des paramètres opératoires

Nikiema, Sompassaté Josiane January 2008 (has links)
The main goal of this work has been that of optimizing the operating conditions of a biofilter, intended for the control of methane, an important greenhouse gas widely emitted by older or smaller landfill installations.The specific objectives were: (1) to select a suitable packing material (of organic or inorganic type); (2) to optimize the concentrations of input nutrients, mainly consisting of nitrogen, phosphorus, potassium and copper, which are intended to be introduced via the nutrient solution; (3) to determine the optimized values of the most important design parameters, such as the methane inlet load (which depends on the air flow rate and the inlet methane concentration); and (4) to model the biofilter performance. Firstly, the comparison of the two packing materials, one of organic type, and the other of inorganic type, has revealed that the latter was the more appropriate material for the methane biofiltration. Then, through the use of the selected packing material, the influence of each individual nutrient on the efficiency of the process has been investigated.The results obtained have shown that both nitrogen and phosphorus concentrations have to be controlled, while potassium and copper were revealed as being nutrients of only minor importance. Secondly, the optimization of the inlet gas flow rate and of the inlet methane concentration (and consequently, of the methane inlet load also), has been performed. According to the results of the studies, these parameters require good control during methane biofiltration because a limitation in biofilter performance could otherwise be induced. In addition, it was noted that the increase in the inlet gas flow rate led generally to a greater decrease of the methane conversion than the one induced by the inlet methane concentration. Finally, a new method, based on the use of solid extracts sampled from the methane biofilter, has been applied to the determination of methane biofilter kinetic parameters. Following this study, a steady state model of the methane biofiltration, taking into consideration the important operational parameters, as identified previously, has been developed. One particular feature of this model is that it takes into consideration the influence of the biofilter average temperature.The prediction results, obtained with the use of the model, have been successfully compared with the experimental results.
104

Sobrecargas retangulares em diferentes domínios de intensidade: respostas cardiorrespiratórias, metabólicas e da percepção subjetiva de esforço em instantes relativos ao tempo de exaustão / Constant workload exercises in different intensity domains: cardiorespiratory, metabolic and perceived exertion responses in different moments relative to the time to exhaustion

Pires, Flávio de Oliveira 11 February 2010 (has links)
Introdução: Em particular, não se sabe se o exercício físico termina com falha da homeostase metabólica em intensidades pertencentes ao domínio moderado, pesado e severo. Este estudo examinou as respostas fisiológicas durante exercícios de sobrecargas constantes até a exaustão, executadas em diferentes domínios metabólicos. Métodos: Dez homens saudáveis executaram quarto cargas constantes as quais corresponderam aos domínios de intensidade moderada (LL1), pesada (LL50% e LL2) e severa (LW25%). Parâmetros metabólicos e cardiorrespiratórios e a percepção subjetiva de esforço (PSE) foram medidos em intervalos regulares de tempo. Resultados: O tempo de exaustão em cada carga constante foi: 93,8 (&#177; 18,0), 77,0 (&#177; 22,9), 44,5 (&#177; 16,0) e 22,8 (&#177; 10,6) minutos em LL1, LL50%, LL2 e LW25%, respectivamente. Quando os dados foram analisados em relação ao tempo absoluto de exercício, significantes variações temporais foram encontradas na razão de trocas respiratórias (RER) e nas concentrações plasmáticas de potássio em LL1; no VO2, VCO2, RER, freqüência respiratória (FR), concentrações plasmáticas de norepinefrina e potássio em LL50%; na RER e nas concentrações plasmáticas de norepinefrina, epinefrina e potássio em LL2; em na RER e concentrações plasmáticas de lactato e potássio em LW25%. Quando os dados foram normalizados pelo tempo de exaustão, algumas significantes variações temporais desapareceram. Exceções foram encontradas para RER e potássio em LL1; RER em LL50%; RER, norepinefrina e potássio em LL2; VE, RR, lactato e potássio em LW25%. Entretanto, com exceção da FR, nenhum outro parâmetro metabólico ou cardiorrespiratório aumentou significantemente depois de decorrido 50% do tempo de exercício, em qualquer das intensidades executadas, indicando a presença de um estado de equilíbrio nas variáveis metabólicas e cardiorrespiratórias, em todos os domínios de intensidade analisados. De outro lado, a PSE apresentou aumentou significante depois de decorrido 50% do tempo de exaustão nos domínios pesado (LL50% e LL2) e severo (LW25%.), quando analisada em termos relativos ao tempo de exaustão. A taxa de incremento da PSE em função do tempo de exercício foi significantemente correlacionada ao tempo de exaustão (r = -0,72 à -0,84; P < 0.05) em todas os domínios de intensidade. Conclusão: A exaustão ocorreu sem clara evidência de falha na homeostase, mesmo em exercício de domínio de intensidade severa, uma vez que não houve significante variação temporal nos parâmetros metabólicos ou cardiorrespiratórios depois de decorrido 50% do tempo de exercício. Estes resultados poderiam sugerir um mecanismo de controle centralmente regulado durante o exercício / Introduction: We wished to determine whether exercise at moderate, heavy and severe intensities terminates with evidence of homeostatic failure. This study verified the physiological responses during exercise to exhaustion in different intensity domains. Methods: Ten healthy men performed prolonged exercise at four constant workloads corresponding to moderate (LT1), heavy (TT50% and LT2) and severe (TW25%) intensity domains. Metabolic and cardiorespiratory parameters and the rating of perceived exertion (RPE) were measured at fixed time intervals. Results: The time to exhaustion was 93.8 (&#177;18.0), 77.0 (&#177; 22.9), 44.5 (&#177; 16.0) and 22.8 (&#177; 10.6) minutes at LT1, TT50%, LT2 and TW25%, respectively. When data were analyzed according to absolute exercise duration, significant temporal variations were found in respiratory exchange ratio (RER) and plasma potassium concentrations in LT1; in VO2, VCO2, RER, respiratory rate (RR), plasma noradrenaline and potassium concentrations in TT50%; in RER, noradrenaline, adrenaline and potassium concentrations in LT2; and in RER and blood lactate and potassium concentrations in TW25%. When data were normalized to 100% of exercise duration, some significant temporal variations disappeared. Exceptions were RER and plasma potassium concentrations in LT1; RER in TT50%; RER and plasma noradrenaline and potassium concentrations in LT2; and VE, RR, blood lactate and plasma potassium concentrations in TW25%. Except for RR, no other cardiorespiratory or metabolic parameter increased significantly after the first 50% of any exercise bout had been completed, indicating the presence of a metabolic and cardiorespiratory steady state at all intensity domains. Conversely, RPE rose progressively in all constant workloads when analyzed in both absolute and relative terms. In addition, the slope at which RPE increased was significantly correlated to time to exhaustion (r = -0.72 to -0.84; P < 0.05) at all exercise intensities. Conclusion: Exercise terminated at all intensities without any indication of homeostatic failure. Since there was no significant variation in cardiorespiratory and metabolic parameters after the completion of 50% of any exercise bout these results might suggest a centrally-regulated control mechanism that defends homeostasis
105

Estudo de parâmetros biomecânicos na marcha e limiares somato-sensoriais em pacientes portadores da neuropatia diabética. / Study of biomechanics parameters in gait analysis and somatic sensorial thresholds of the diabetic neuropathic patients

Sacco, Isabel de Camargo Neves 03 December 1997 (has links)
O presente estudo, através de metodologia sistematizada envolvendo testes eletrodiagnósticos e avaliações dinâmicas da marcha, objetivou analisar e interpretar parâmetros biomecânicos e eletrofisiológicos relacionadas à neuropatia diabética durante a marcha. Analisou e interpretou-se parâmetros temporais, de distribuição da pressão plantar e força reação do solo, adquiridos através de um equipamento específico para tal fim para três grupos experimentais. Analisou-se parâmetros da eletrofisiologia indicadores de respostas somato-sensoriais: cronaxia sensitiva e tolerância à dor em regiões anatomicamente determinadas da superfície plantar. Com tais parâmetros, buscou-se definir os padrões da marcha de indivíduos neuropatas ou não, para intervir de forma mais complexa na descrição e interpretação da doença. Investigou-se relações de dependência entre as variáveis dinâmicas e as eletrofisiológicas como forma de entender outros fatores intervenientes na etiologia das lesões decorrentes, bem como nas alterações compensatórias dinâmicas na marcha desses pacientes, alterações essas que são bilaterais e necessárias para a adaptação devido ao déficit sensorial decorrente da neuropatia. Apesar de não ter sido observada correlação entre estas variáveis, vale ressaltar que esse relacionamento torna-se cada vez mais importante para a compreensão da doença e interpretação de suas diferentes respostas adaptativas na avaliação do comportamento da marcha humana / The purpose of this study is to investigate electrophysiological parameters related to diabetic neuropathy and biomechanical parameters during gait, by systemized methodology, including electrodiagnostic tests and dynamic gait evaluation. We have analysed temporal aspects during stance phase, plantar pressure distribution, and ground reaction forces, acquired by an specific equipment in three experimental groups. We also have studied electrophysiological parameters related to somatic sensorial responses, like sensitive cronaxie and pain tolerance threshold, in some specific anatomical areas of plantar surface. Within these parameters, we searched for defined gait patterns in neuropathic diabetic patients, as well as in diabetic patients without neuropathy, to intervene in a more complex description and interpretation of the disease. We also looked for some relations of dependency between dynamic and electrophysiological variables as a contribution to the better undestanding of the disease ethiology and dynamic compensatory mechanisms in pathological gait. These compensatory mechanisms are usually bilateral, because it is a way of adapting to the sensorial deficit due to the neuropathy. Although there are no observed correlation between these variables, it is good to emphasize that such relationship becomes gradually more important to the understanding of the disease and the interpretation of its different adaptative reactions in human locomotion
106

Mars Exploration Rover (MER) Panoramic Camera (Pancam) Twilight Image Analysis for Determination of Planetary Boundary Layer and Dust Particle Size Parameters

Grounds, Stephanie Beth 2010 December 1900 (has links)
How the dust cycle works on Mars is a key atmospheric issue, as the dust cycle is arguably the dominant cycle in the current Martian climate. In addition, how much is known about the Martian planetary boundary layer is mostly determined from models with very little in-situ data from contemporaneous studies to validate such boundary layer characteristic assumptions, and the model studies have not been able to define a known height for a possible boundary layer on Mars using ground-based investigations prior to this research. The Mars Exploration Rovers (MERs), however, show promise in offering a unique chance to take surface-based measurements to offer support for dust and boundary layer measurements made from remote sensors. There are three main objectives of this study: to constrain the late-afternoon maximum height of the boundary layer for both MER sites, to constrain the mean particle size and variance of the size distribution in the atmosphere, and to use these results to demonstrate that sunset and twilight imaging is a useful survey of otherwise difficult-to-determine parameters that are needed in several tools for studying Mars’ atmosphere. A modeling approach using twilight-based Sun imaging by the MERs (Sol 1959 for Spirit and Sol 695 for Opportunity) is used to constrain boundary layer and dust particle size parameters. After determining which parameters control which observables, resulting elevations and azimuths are matched up to specific observations from the available MER datasets. A Monte Carlo code produces the model that is then compared to Sol data with plotting of resulting error. Results include PBL height and structure estimations and plots along with generalized particle size information for each MER site on the given Sol. Figures show comparisons of this study’s particle size results with that of previous studies as well as maps of fit qualities for boundary layer parameters compared to a contemporaneous modeled scale height estimation. Results show promise for planning future MER-based campaigns and models.
107

Comparison Of Engine Performance And Emissions For Conventional Petroleum Diesel Fuel And Diesel-ethanol Blends

Erkal, Gul 01 April 2010 (has links) (PDF)
Ethanol is an environmental friendly alternative diesel fuel that has received significant attention both as a possible renewable alternative fuel and as an additive to existing petroleum-based fuels. Beyond simply representing an additional fuel supply, ethanol exhibits several advantages when compared to existing petroleum fuel. The objective of this work is to investigate experimentally the effects of using different blends of specified percentages of ethanol on the engine performance and emissions and to compare it with that of conventional diesel fuel. Tests will be done on the &lsquo / &lsquo / Engine Test Laboratory&rsquo / &rsquo / of the Turkish Tractor Factory (TTF) using a fourcylinder, turbocharged and naturally aspirated, DI diesel engines. Engine performance parameters such as engine speed, torque, power, fuel consumption will be measured. At the same time, the engine emissions including particulate matter, unburned hydrocarbons, carbon monoxide, and NOX will also be recorded.
108

Balanços eletrolíticos na dieta de poedeiras em segundo ciclo sob altas temperaturas. /

Cavalhieri, Jéssica Pinoti January 2018 (has links)
Orientador: Rosemeire da Silva Filardi / Resumo: Em diversas regiões do Brasil, o desempenho das aves é afetado negativamente pelas variações climáticas. Altas temperaturas associadas a alta umidade relativa do ar determinam muitas alterações fisiológicas, dentre elas os distúrbios acidobásicos, diminuição no desempenho produtivo das aves e na qualidade externa dos ovos. Dentro desta problemática, o estudo avaliou os efeitos de níveis do balanço parcial de cátions-ânions na dieta (Na+ + K+ - Cl-), balanço eletrolítico (BE), sobre as respostas produtivas, qualidade dos ovos, hemograma e parâmetros bioquímicos de poedeiras comerciais em segundo ciclo de produção, mantidas em condições de altas temperaturas e umidade. Cento e vinte e oito poedeiras comerciais em segundo ciclo produtivo, com 122 semanas de idade, foram distribuídas em um delineamento inteiramente casualizado em esquema de parcelas subdivididas, onde ciclo foi considerado como apenas uma medida repetida no tempo, composto por quatro balanços eletrolíticos (170, 220, 270, 320 mEq.kg-1), quatro repetições de oito aves cada em quatro ciclos de 14 dias, perfazendo um total de 56 dias de experimento. Ao final do experimento foram obtidas amostras sanguíneas de duas aves por parcela para determinar o hemograma e parâmetros bioquímicos sanguíneos. Os BE influenciaram o consumo de ração (P<0,01), a produção (P<0,05) e massa de ovos (P<0,01), tendo comportamento quadrático para essas variáveis. Considerando-se o comportamento da produção e da massa de ovos o valor médio ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In several regions of Brazil, the performance of laying hens is affecting negatively by climatic variations. High temperatures and relative humidity determine many physiological changes, among them the acid-base disturbances, decrease in the productive performance of the laying hens and the external quality of the eggs. In this problem, the study evaluated the effects of partial levels of cation-anions in the diet (Na+ + K+ - Cl-), electrolytic balance (BE), on productive responses, egg quality, hemogram and biochemical parameters of laying hens in the second production cycle maintained under high temperature and humidity conditions. One hundred and twenty-eight commercial laying hens in the second productive cycle, at 122 weeks of age, were distributed in a completely randomized design in subdivided plots scheme, where cycle was considered as only one measure repeated in time, composed of four electrolytic balances (170 , 220, 270, 320 mEq.kg-1), four replicates of eight laying hens each in four cycles of 14 days, making a total of 56 days of experiment. At the end of the experiment blood samples of two laying hens were obtained per plot to determine the hemogram and blood biochemical parameters. The BE influenced feed intake (P <0.01), production (P <0.05) and egg mass (P <0.01), with quadratic behavior for these variables. Considering the production behavior and egg mass, the mean electrolytic balance value 265.24 mEq.kg-1 provided the best result. Within the ranges of the... (Complete abstract click electronic access below) / Mestre
109

Studies of laser brazing with regard to the quality influencing parameters

Ernst, Sabrina January 2015 (has links)
Laser joining processes, such as brazing and welding, are a common application in industry, especially in the automotive industry. These processes are the key to lightweight and efficient design with regard to the automotive industry. There, laser brazing is used mainly for visible joints due to the superior paint adhesion and surface roughness of brazed joints compared to welds. As laser brazing is applied in the automotive industry without using any fluxes or shielding gas, this leads to a difficulty in maintaining and ensuring the quality of brazed joints.
110

Estrutura populacional e estimação de parâmetros genéticos para características associadas ao desempenho reprodutivo em bovinos da raça Caracu / Population structure and genetic parameters estimation for economic importance traits in Caracu cattle

Barrera Carvajal, Alejandro [UNESP] 27 July 2017 (has links)
Submitted by Alejandro Barrera Carvajal null (alejandrobarreracarvajal@gmail.com) on 2017-10-05T04:26:06Z No. of bitstreams: 1 Dissertaçao_Alejandro_Barrera_Carvajal.pdf: 1237994 bytes, checksum: b3cc225c970d5d4a261bca85aee4a212 (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-10-09T16:57:38Z (GMT) No. of bitstreams: 1 barreracarvajal_a_me_jabo.pdf: 1237994 bytes, checksum: b3cc225c970d5d4a261bca85aee4a212 (MD5) / Made available in DSpace on 2017-10-09T16:57:38Z (GMT). No. of bitstreams: 1 barreracarvajal_a_me_jabo.pdf: 1237994 bytes, checksum: b3cc225c970d5d4a261bca85aee4a212 (MD5) Previous issue date: 2017-07-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O conhecimento da estrutura de uma população é importante quando se deseja manter a variabilidade genética em programas de melhoramento genético. As estimativas dos parâmetros genéticos permitem identificar as características de interesse econômico que podem responder a seleção direta ou indireta. Neste trabalho, objetivou-se avaliar a estrutura genética populacional e estimar os parâmetros genéticos para as características peso corporal da fêmea na entrada (PEP) e na saída (PSP) da primeira estação de monta, idade ao primeiro parto (IPP), peso corporal da vaca ao primeiro parto (PPP), peso corporal da vaca ao primeiro desmame (PPD) e perímetro escrotal aos 378 dias (PE378) em bovinos da raça Caracu, para avaliar critérios de seleção e os procedimentos de acasalamento para manter a variabilidade genética da população. A estrutura genética da população foi avaliada pelo tamanho efetivo (Ne), número efetivo de fundadores (fe), número efetivo de ancestrais (fa), intervalos de geração, coeficiente de endogamia (F), coeficiente de parentesco médio (AR) e integridade do pedigree. Os parâmetros genéticos foram estimados pelo método de máxima verossimilhança restrita (REML) por meio de modelo animal multi-característica. Os resultados obtidos para Ne na geração máxima, completa e equivalente, foram 180,90; 57,39; e 92,38, respectivamente. O valor para fe foi de 199 e para fa de 27. O coeficiente de endogamia médio e o parentesco médio foram 2,14% e 5,72%, respectivamente. Na avaliação da integridade do pedigree foram identificados 94,83% das mães e 93,82% dos pais com registros de origem. As estimativas de herdabilidade para as características de peso corporal variaram de 0,37 ± 0,09 (PPP) a 0,46 ± 0,08 (PPD). Para as características reprodutivas, as estimativas de herdabilidade foram 0,31 ± 0,10 para PE378 e 0,10 ± 0,06 para IPP. As correlações genéticas variaram de -0,37 ± 0,30 (PE378 e IPP) a 0,94 ± 0,06 (PSP e PPP). As correlações genéticas entre os pesos corporais medidos durante o primeiro ciclo reprodutivo e IPP indicaram que a seleção visando controlar o peso corporal nesse período não irá afetar a idade ao primeiro parto. A correlação genética favorável obtida entre PE378 e IPP (-0,37±0,30) indicou que a seleção para PE378 nos machos poderá favorecer a redução de idade ao primeiro parto das fêmeas. A partir dos parâmetros populacionais, concluiu-se que a variabilidade genética da população tem sido mantida, assim como os níveis de endogâmia, em decorrência do controle dos acasalamentos no decorrer das gerações. / The knowledge of the structure of the population is important to desired to maintain genetic variability in breeding programs. The genetic parameters estimates allow identifying economic interest traits that can respond to direct or indirect selection. The goal of this study was to evaluate the population genetic structure and to estimate the genetic parameters for the body weight of the cow at the beginning (WBF) and at the end (WEF) of the first breeding season, age at first calving (AFC), body weight of cow at first calving (WFC), body weight of cow at first weaning (WFW) and scrotal circumference measured at 378 days (SC378) in Caracu beef cattle, to assess the selection criteria and to indicate mating procedures to maintain the genetic diversity of the population. The genetic structure of the population was verified of the effective population size (Ne), the effective number of the founders (fe), the effective number of the ancestors (fa), the generational intervals, the inbreeding coefficient (F), the average relatedness (AR) and of the pedigree integrity. The restricted maximum likelihood method (REML) was used to estimate the genetic parameters under multitrait animal model. The maximum, complete and equivalent generation for Ne was 180.90; 57.39 and 92.38, respectively. For the fe were 199 and for fa 27. The average of the inbreeding coefficient and the AR were 2.14% and 5.72%, respectively. The integrity of the pedigree identified was 94.83% of the dam and 93.82% of the sire with known initial records Estimates of heritability for body weight traits ranged from 0.37 ± 0.09 (WFC) to 0.46 ± 0.08 (WFW). For the reproductive traits, the heritability estimates were 0.31 ± 0.10 for SC378 and 0.10 ± 0.06 for AFC. Genetic correlations ranged from -0.37 ± 0.30 (SC378 and AFC) to 0.94 ± 0.06 (WEF and WFC). Genetic correlations between body weights measured during the first reproductive cycle and the AFC indicated that selection to control body weight in this period will not affect age at first calving. The favorable genetic correlation obtained between SC378 and AFC (-0.37 ± 0.30) indicated that selection for SC378 of males may reduce the age at first calving of females. The population parameters showed that the genetic variability of the population has been maintained, as well as the levels of the inbreeding due to the control of mating during the generations.

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