996 resultados para Air injection
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The present work aimed to study the composting process using two methods of treatment, conventional and mechanized for the treatment of pruning/weeding waste and organic waste generated in the canteens of the FCT/UNESP. For this work, it was quantified the generation of the waste However, of the tests with pure organic compound, which had the best result was T1 - 70% RPC / 30% ROC, again indicating the feasibility of applying this condition in scales at the campus. The conventional treatment by composting was carried out on manual aerated piles: 70% residue pruning/weeding (RPC) and 30% organic waste from the canteen (ROC); 50% RPC / 50% ROC, 30% RPC / 70% ROC. The mechanized system consisted of a reactor of 190 liters – 50% RPC / 50% ROC, with air injection from a compressor for 15 minutes daily. The parameters characterized and monitored were pH, organic matter, organic carbon, ash, nitrogen kjedahl and phosphorus. The temperature measurements were taken daily by a digital thermocouple (top, middle and base of the piles and reactor)... (Completo abstract click electronic access below)
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Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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INTRODUÇÃO: Durante procedimentos endovasculares, estão presentes os riscos relacionados ao uso dos contrastes iodados, tais como a nefropatia por contraste, uma vez que é fundamental o emprego de um meio de contraste para a obtenção das imagens radiológicas vasculares. A injeção intravascular de gás CO2 purificado é reconhecidamente uma alternativa relativamente mais segura ao contraste iodado, contudo, seu manuseio artesanal pode também trazer dificuldades técnicas e riscos aos pacientes. Para contemplar estas questões, foi desenvolvido o protótipo de um injetor intravascular de CO2 medicinal, microprocessado, dedicado à obtenção de imagens angiográficas. OBJETIVOS: Realizar os testes de viabilidade técnica inicial do protótipo em modelo in vivo. MÉTODOS: Realizar a angioplastia da artéria renal esquerda de 10 porcos, divididos em 2 grupos: Grupo 1 (n=5) injeção de contraste iodado, Grupo 2 (n=5) injeção de CO2 através do protótipo. Monitorização clínica e laboratorial dos animais no pré, intra e pós-operatório, com exames de função renal na véspera e 48h após os procedimentos e 3 gasometrias arteriais seriadas no intra-operatório. Observação clínica foi mantida por 48h no pós- operatório. RESULTADOS: Os procedimentos de angioplastia com CO2 foram realizados com sucesso técnico de 100%, sem necessidade de complementação com injeção de contraste iodado no Grupo 2. Não foram identificadas falhas no protótipo em funcionamento. Não foram identificadas alterações clínicas ou radiológicas sugestivas de contaminação por ar ambiente do sistema de CO2 e nem alterações laboratoriais nos animais. As imagens angiográficas obtidas no Grupo 2 foram consideradas, numa avaliação subjetiva, relativamente inferiores às imagens obtidas no Grupo 1. DISCUSSÃO: A qualidade inferior de imagem no Grupo 2 pode ser atribuída ao equipamento de fluoroscopia utilizado, com software desatualizado em relação aos equipamentos atuais, que incluem pré-configurações para angiografia com CO2; no entanto, ainda assim todos os procedimentos propostos no Grupo 2 foram realizados com sucesso técnico, o que nos leva a classificar as imagens deste grupo 2 como satisfatórias. O manuseio do aparelho mostrou-se ágil e eficiente, com a programação dos parâmetros sendo realizada com facilidade através do visor \"touch screen\", comparativamente superior ao método artesanal de injeção de CO2 com seringas em selo d\'água. CONCLUSÕES: O protótipo do aparelho injetor intravascular de CO2 funcionou de forma adequada durante os testes e as imagens obtidas permitiram a compleição com sucesso dos procedimentos. Portanto, os resultados positivos obtidos sugerem que o equipamento é tecnicamente viável
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With an increasing number of mature fields, heavy oil recovery has performed one of the great challenges of the oil industry. The Brazilian Northeast, for example, has numerous heavy oil reservoirs are explored with the use of thermal methods. Among the types of methods used for heavy oil, there is the method of in-situ combustion, a technique in which heat is produced within the container, unlike the injection of heated fluid when the heat is generated at the surface and transported to the reservoir. In this type of process, it is common to use vertical wells as injectors and producers. However, methods which use horizontal wells like oil producers are increasingly studied because of greater contact area between the formation and combustion front. Thus, the main objective of this work was to study the different configurations of wells (CIS THAITM and CAGD) in the process of in-situ combustion in oil recovery using a semi-synthetic tank with Brazilian Northeast features. The method "toe-to-heel air injection" (THAITM) is a process of enhanced oil recovery, which is the integration of in-situ combustion with technological advances in drilling horizontal wells. This method uses horizontal wells such as oil producers, keeping vertical injection wells for injecting air. The oil drain process by differential gravitational assisted with combustion (CAGD) is an integrated, in this configuration the horizontal injector well is drilled at the top formation with a horizontal production well in the lower section. The simulations were performed in a commercial program of thermal processes, called "STARS" (Steam, Thermal, and Advanced Processes Reservoir Simulator), the company CMG (Computer Modelling Group). An analysis of the air flow injection was performed and it was found that each method had a maximum injection to the base model, a show that through this air injection limit was reduced cumulative production of oil. Analyses of operating parameters were used: injection flow, configuration and completion of wells. In the sensitivity analysis we found that the air injection flow showed greater influence on THAI method, since the CIS method the completion of the wells was the most influential parameter and CAGD configuration wells showed the greatest influence in the recovered fraction. The economic results have shown that the best case obtained in CAGD method because, despite having higher initial cost showed the best financial return compared to the best cases the CIS and THAI.
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With an increasing number of mature fields, heavy oil recovery has performed one of the great challenges of the oil industry. The Brazilian Northeast, for example, has numerous heavy oil reservoirs are explored with the use of thermal methods. Among the types of methods used for heavy oil, there is the method of in-situ combustion, a technique in which heat is produced within the container, unlike the injection of heated fluid when the heat is generated at the surface and transported to the reservoir. In this type of process, it is common to use vertical wells as injectors and producers. However, methods which use horizontal wells like oil producers are increasingly studied because of greater contact area between the formation and combustion front. Thus, the main objective of this work was to study the different configurations of wells (CIS THAITM and CAGD) in the process of in-situ combustion in oil recovery using a semi-synthetic tank with Brazilian Northeast features. The method "toe-to-heel air injection" (THAITM) is a process of enhanced oil recovery, which is the integration of in-situ combustion with technological advances in drilling horizontal wells. This method uses horizontal wells such as oil producers, keeping vertical injection wells for injecting air. The oil drain process by differential gravitational assisted with combustion (CAGD) is an integrated, in this configuration the horizontal injector well is drilled at the top formation with a horizontal production well in the lower section. The simulations were performed in a commercial program of thermal processes, called "STARS" (Steam, Thermal, and Advanced Processes Reservoir Simulator), the company CMG (Computer Modelling Group). An analysis of the air flow injection was performed and it was found that each method had a maximum injection to the base model, a show that through this air injection limit was reduced cumulative production of oil. Analyses of operating parameters were used: injection flow, configuration and completion of wells. In the sensitivity analysis we found that the air injection flow showed greater influence on THAI method, since the CIS method the completion of the wells was the most influential parameter and CAGD configuration wells showed the greatest influence in the recovered fraction. The economic results have shown that the best case obtained in CAGD method because, despite having higher initial cost showed the best financial return compared to the best cases the CIS and THAI.
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Experimental and analytical studies were conducted to explore thermo-acoustic coupling during the onset of combustion instability in various air-breathing combustor configurations. These include a laboratory-scale 200-kW dump combustor and a 100-kW augmentor featuring a v-gutter flame holder. They were used to simulate main combustion chambers and afterburners in aero engines, respectively. The three primary themes of this work includes: 1) modeling heat release fluctuations for stability analysis, 2) conducting active combustion control with alternative fuels, and 3) demonstrating practical active control for augmentor instability suppression. The phenomenon of combustion instabilities remains an unsolved problem in propulsion engines, mainly because of the difficulty in predicting the fluctuating component of heat release without extensive testing. A hybrid model was developed to describe both the temporal and spatial variations in dynamic heat release, using a separation of variables approach that requires only a limited amount of experimental data. The use of sinusoidal basis functions further reduced the amount of data required. When the mean heat release behavior is known, the only experimental data needed for detailed stability analysis is one instantaneous picture of heat release at the peak pressure phase. This model was successfully tested in the dump combustor experiments, reproducing the correct sign of the overall Rayleigh index as well as the remarkably accurate spatial distribution pattern of fluctuating heat release. Active combustion control was explored for fuel-flexible combustor operation using twelve different jet fuels including bio-synthetic and Fischer-Tropsch types. Analysis done using an actuated spray combustion model revealed that the combustion response times of these fuels were similar. Combined with experimental spray characterizations, this suggested that controller performance should remain effective with various alternative fuels. Active control experiments validated this analysis while demonstrating 50-70\% reduction in the peak spectral amplitude. A new model augmentor was built and tested for combustion dynamics using schlieren and chemiluminescence techniques. Novel active control techniques including pulsed air injection were implemented and the results were compared with the pulsed fuel injection approach. The pulsed injection of secondary air worked just as effectively for suppressing the augmentor instability, setting up the possibility of more efficient actuation strategy.
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The occurrence of heavy oil reservoirs have increased substantially and, due to the high viscosity characteristic of this type of oil, conventional recovery methods can not be applied. Thermal methods have been studied for the recovery of this type of oil, with a main objective to reduce its viscosity, by increasing the reservoir temperature, favoring the mobility of the oil and allowing an increasing in the productivity rate of the fields. In situ combustion (ISC) is a thermal recovery method in which heat is produced inside the reservoir by the combustion of part of the oil with injected oxygen, contrasting with the injection of fluid that is heated in the surface for subsequent injection, which leads to loss heat during the trajectory to the reservoir. The ISC is a favorable method for recovery of heavy oil, but it is still difficult to be field implemented. This work had as an objective the parametric analysis of ISC process applied to a semi-synthetic reservoir with characteristics of the Brazilian Northeast reservoirs using vertical production and vertical injection wells, as the air flow injection and the wells completions. For the analysis, was used a commercial program for simulation of oil reservoirs using thermal processes, called Steam, Thermal and Advanced Processes Reservoir Simulator (STARS) from Computer Modelling Group (CMG). From the results it was possible to analyze the efficiency of the ISC process in heavy oil reservoirs by increasing the reservoir temperature, providing a large decrease in oil viscosity, increasing its mobility inside the reservoir, as well as the improvement in the quality of this oil and therefore increasing significantly its recovered fraction. Among the analyzed parameters, the flow rate of air injection was the one which had greater influence in ISC, obtaining higher recovery factor the higher is the flow rate of injection, due to the greater amount of oxygen while ensuring the maintenance of the combustion front
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The injection stretch blow moulding process involves the inflation and stretching of a hot preform into a mould to form bottles. A critical process variable and an essential input for process simulations is the rate of pressure increase within the preform during forming, which is regulated by an air flow restrictor valve. The paper describes a set of experiments for measuring the air flow rate within an industrial ISBM machine and the subsequent modelling of it with the FEA package ABAQUS. Two rigid containers were inserted into a Sidel SBO1 blow moulding machine and subjected to different supply pressures and air flow restrictor settings. The pressure and air temperature were recorded for each experiment enabling the mass flow rate of air to be determined along with an important machine characteristic known as the ‘dead volume’. The experimental setup was simulated within the commercial FEA package ABAQUS/Explicit using a combination of structural, fluid and fluid link elements that idealize the air flowing through an orifice behaving as an ideal gas under isothermal conditions. Results between experiment and simulation are compared and show a good correlation.
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Includes indexes.
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Includes index.
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"December 1977."
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Otto-von-Guericke-Universität Magdeburg, Fakultät für Verfahrens- und Systemtechnik, Dissertation, 2016