1000 resultados para Arvores - Temperatura
Resumo:
Os dispositivos de monitorização de estado de saúde começam a destacar-se no mercado como uma mais-valia na antecipação e precaução de possíveis falhas vitais. Com base na interacção entre o cuidador e o paciente, desenvolveu-se um monitorizador da temperatura corporal minimamente invasivo orientado para as crianças. O projecto foi desenvolvido em parceria com a empresa EDIN. O projecto divide-se em duas etapas. Na primeira etapa foi elaborada uma análise ao problema, onde foi realizado um levantamento da tipologia de produtos comerciais e um inquérito à população, com o objectivo de enumerar alguns dos requisitos do produto a desenvolver. A segunda etapa destinou-se ao desenvolvimento do projecto. Após a validação das especificações resultantes da etapa anterior, procedeu-se à criação de conceitos, através de brainstorming, com o objectivo de seleccionar o modelo final. Posteriormente, o produto foi protótipado e testado pelo públicoalvo e pelos cuidadores, permitindo, através do feedback obtido, efectuar melhorias ao nível do conforto do utilizador. Foi também desenvolvido o protótipo de um interface para uma aplicação móvel, que permite ao cuidador, quer conhecer a temperatura corporal da criança e sua evolução, quer o estado de carga da bateria e autonomia do produto, entre outros. Este projecto apresenta assim um novo produto, capaz de responder às necessidades do consumidor, contribuindo para um aumento da prevenção e diagnóstico do estado de saúde das crianças, com o mínimo de perturbação destas.
Resumo:
The improved performance of hydraulic binders, the base of Portland cement, consists in the careful selection and application of materials that promote greater durability and reduced maintenance costs There is a wide variety of chemical additives used in Portland cement slurries for cementing oil wells. These are designed to work in temperatures below 0 ° C (frozen areas of land) to 300 ° C (thermal recovery wells and geothermal); pressure ranges near ambient pressure (in shallow wells) to greater than 200 MPa (in deep wells). Thus, additives make possible the adaptation of the cement slurries for application under various conditions. Among the materials used in Portland cement slurry, for oil wells, the materials with nanometer scale have been applied with good results. The nanossílica, formed by a dispersion of SiO2 particles, in the nanometer scale, when used in cement systems improves the plastic characteristics and mechanical properties of the hardened material. This dispersion is used commercially as filler material, modifier of rheological properties and / or in recovery processes construction. It is also used in many product formulations such as paints, plastics, synthetic rubbers, adhesives, sealants and insulating materials Based on the above, this study aims to evaluate the performance of nanossílica as extender additive and improver of the performance of cement slurries subjected to low temperatures (5 ° C ± 3 ° C) for application to early stages of marine oil wells. Cement slurries were formulated, with densities 11.0;12.0 and 13.0 ppg, and concentrations of 0; 0.5, 1.0 and 1.5%. The cement slurries were subjected to cold temperatures (5 ° C ± 3 ° C), and its evaluation performed by tests rheological stability, free water and compressive strength in accordance with the procedures set by API SPEC 10A. Thermal characterization tests (TG / DTA) and crystallographic (XRD) were also performed. The use of nanossílica promoted reduction of 30% of the volume of free water and increased compression resistance value of 54.2% with respect to the default cement slurry. Therefore, nanossílica presented as a promising material for use in cement slurries used in the early stages of low-temperature oil wells
Resumo:
In the oil industry, natural gas is a vital component of the world energy supply and an important source of hydrocarbons. It is one of the cleanest, safest and most relevant of all energy sources, and helps to meet the world's growing demand for clean energy in the future. With the growing share of natural gas in the Brazil energy matrix, the main purpose of its use has been the supply of electricity by thermal power generation. In the current production process, as in a Natural Gas Processing Unit (NGPU), natural gas undergoes various separation units aimed at producing liquefied natural gas and fuel gas. The latter should be specified to meet the thermal machines specifications. In the case of remote wells, the process of absorption of heavy components aims the match of fuel gas application and thereby is an alternative to increase the energy matrix. Currently, due to the high demand for this raw gas, research and development techniques aimed at adjusting natural gas are studied. Conventional methods employed today, such as physical absorption, show good results. The objective of this dissertation is to evaluate the removal of heavy components of natural gas by absorption. In this research it was used as the absorbent octyl alcohol (1-octanol). The influence of temperature (5 and 40 °C) and flowrate (25 and 50 ml/min) on the absorption process was studied. Absorption capacity expressed by the amount absorbed and kinetic parameters, expressed by the mass transfer coefficient, were evaluated. As expected from the literature, it was observed that the absorption of heavy hydrocarbon fraction is favored by lowering the temperature. Moreover, both temperature and flowrate favors mass transfer (kinetic effect). The absorption kinetics for removal of heavy components was monitored by chromatographic analysis and the experimental results demonstrated a high percentage of recovery of heavy components. Furthermore, it was observed that the use of octyl alcohol as absorbent was feasible for the requested separation process.
Resumo:
In the oil industry, natural gas is a vital component of the world energy supply and an important source of hydrocarbons. It is one of the cleanest, safest and most relevant of all energy sources, and helps to meet the world's growing demand for clean energy in the future. With the growing share of natural gas in the Brazil energy matrix, the main purpose of its use has been the supply of electricity by thermal power generation. In the current production process, as in a Natural Gas Processing Unit (NGPU), natural gas undergoes various separation units aimed at producing liquefied natural gas and fuel gas. The latter should be specified to meet the thermal machines specifications. In the case of remote wells, the process of absorption of heavy components aims the match of fuel gas application and thereby is an alternative to increase the energy matrix. Currently, due to the high demand for this raw gas, research and development techniques aimed at adjusting natural gas are studied. Conventional methods employed today, such as physical absorption, show good results. The objective of this dissertation is to evaluate the removal of heavy components of natural gas by absorption. In this research it was used as the absorbent octyl alcohol (1-octanol). The influence of temperature (5 and 40 °C) and flowrate (25 and 50 ml/min) on the absorption process was studied. Absorption capacity expressed by the amount absorbed and kinetic parameters, expressed by the mass transfer coefficient, were evaluated. As expected from the literature, it was observed that the absorption of heavy hydrocarbon fraction is favored by lowering the temperature. Moreover, both temperature and flowrate favors mass transfer (kinetic effect). The absorption kinetics for removal of heavy components was monitored by chromatographic analysis and the experimental results demonstrated a high percentage of recovery of heavy components. Furthermore, it was observed that the use of octyl alcohol as absorbent was feasible for the requested separation process.
Resumo:
The advance of drilling in deeper wells has required more thermostable materials. The use of synthetic fluids, which usually have a good chemical stability, faces the environmental constraints, besides it usually generate more discharge and require a costly disposal treatment of drilled cuttings, which are often not efficient and require mechanical components that hinder the operation. The adoption of aqueous fluids generally involves the use of chrome lignosulfonate, used as dispersant, which provides stability on rheological properties and fluid loss under high temperatures and pressures (HTHP). However, due to the environmental impact associated with the use of chrome compounds, the drilling industry needs alternatives that maintain the integrity of the property and ensure success of the operation in view of the strong influence of temperature on the viscosity of aqueous fluids and polymers used in these type fluids, often polysaccharides, passives of hydrolysis and biological degradation. Therefore, vinyl polymers were selected for this study because they have predominantly carbon chain and, in particular, polyvinylpyrrolidone (PVP) for resisting higher temperatures and partially hydrolyzed polyacrylamide (PHPA) and clay by increasing the system's viscosity. Moreover, the absence of acetal bonds reduces the sensitivity to attacks by bacteria. In order to develop an aqueous drilling fluid system for HTHP applications using PVP, HPAM and clay, as main constituents, fluid formulations were prepared and determined its rheological properties using rotary viscometer of the Fann, and volume filtrate obtained by filtration HTHP following the standard API 13B-2. The new fluid system using polyvinylpyrrolidone (PVP) with high molar weight had higher viscosities, gels and yield strength, due to the effect of flocculating clay. On the other hand, the low molecular weight PVP contributed to the formation of disperse systems with lower values in the rheological properties and fluid loss. Both systems are characterized by thermal stability gain up to around 120 ° C, keeping stable rheological parameters. The results were further corroborated through linear clay swelling tests.
Resumo:
The advance of drilling in deeper wells has required more thermostable materials. The use of synthetic fluids, which usually have a good chemical stability, faces the environmental constraints, besides it usually generate more discharge and require a costly disposal treatment of drilled cuttings, which are often not efficient and require mechanical components that hinder the operation. The adoption of aqueous fluids generally involves the use of chrome lignosulfonate, used as dispersant, which provides stability on rheological properties and fluid loss under high temperatures and pressures (HTHP). However, due to the environmental impact associated with the use of chrome compounds, the drilling industry needs alternatives that maintain the integrity of the property and ensure success of the operation in view of the strong influence of temperature on the viscosity of aqueous fluids and polymers used in these type fluids, often polysaccharides, passives of hydrolysis and biological degradation. Therefore, vinyl polymers were selected for this study because they have predominantly carbon chain and, in particular, polyvinylpyrrolidone (PVP) for resisting higher temperatures and partially hydrolyzed polyacrylamide (PHPA) and clay by increasing the system's viscosity. Moreover, the absence of acetal bonds reduces the sensitivity to attacks by bacteria. In order to develop an aqueous drilling fluid system for HTHP applications using PVP, HPAM and clay, as main constituents, fluid formulations were prepared and determined its rheological properties using rotary viscometer of the Fann, and volume filtrate obtained by filtration HTHP following the standard API 13B-2. The new fluid system using polyvinylpyrrolidone (PVP) with high molar weight had higher viscosities, gels and yield strength, due to the effect of flocculating clay. On the other hand, the low molecular weight PVP contributed to the formation of disperse systems with lower values in the rheological properties and fluid loss. Both systems are characterized by thermal stability gain up to around 120 ° C, keeping stable rheological parameters. The results were further corroborated through linear clay swelling tests.
Resumo:
As time passed, humanity needed the development of new materials used in various activities. High strength materials such as titanium and Inconel for example, had been studied because they are widely used for implants in biomedicine, as well as their use in aerospace and automotive industries. Because of its thermal and mechanical properties, these materials are considered difficult to machine, promoting a rapid wear of cutting tools, primarily caused by the high temperatures in machining. With the development of new materials has emerged the need of developing new manufacturing processes. One of today’s innovative processes is the micro-manufacturing. Being a process with a defined cutting tool geometry, burr formation is a constant and undesirable phenomenon formed during the machininig process. Being detrimental to the manufacturing process, overspending deburring operations are constantly employed leading to increase the aggregate cost to the manufactured material. Assembly components are also impaired if there is no control of the burr, with consequences including the disposal of components due to the occurence of this phenomenon. This paper presents the study of micro-milling Inconel 718, investigating influential parameters in the formation of burrs in order to minimize the occurrence of this phenome non. Different feed rates per tooth and cutting speed are evaluated, and different cutting fluids with different methods of applying the fluid. Adding graphene to cutting fluids was considered as a variable to be investigated, which is considered an excellent solid lubricant, in addition to increasing the thermal conductivity of the cooling solution (AZIMI; MOZAF FARI, 2015). The micro-milling temperature was evaluated in the present work. It was observed a new phenomenon that causes the machined surface temperature decreases below room temperature when using the solution water + oil. This phenomenon is explained in further chapters. In order to unravel this phenomenon, a new test was proposed and, from this test, it can be concluded, comparatively, which cutting fluid has a better cooling property.Using cutting fluid with different thermal properties has shown influence when analy zing burr formation and reducing machining temperature.
Resumo:
Las respuestas de los componentes del rendimiento y de la calidad del aceite a la temperatura aún no han sido estudiadas en olivo ni en otras oleaginosas que acumulan aceite principalmente en mesocarpo (cerca de 95 por ciento del total en el caso de olivo). La información disponible en olivo se basa en correlaciones ligadas a variaciones en ubicación geográfica, altitud y años en los que pudieron covariar con la temperatura otros factores (radiación, disponibilidad hídrica, nutrición, etc). El objetivo de esta tesis fue evaluar el rol de la temperatura durante el crecimiento de frutos de olivo sobre el peso seco de los mismos, su contenido y concentración de aceite y las proporciones de ácidos grasos del aceite. Se realizaron experimentos manipulativos aplicados a ramas fructíferas creciendo a campo, utilizando cámaras transparentes con control y registro de temperatura. Los rangos de temperaturas medias alcanzados (entre 15-32 ºC) fueron mucho mayores a los rangos de 1 y 4 ºC logrados en estudios correlativos y permitieron generar relaciones funcionales para el peso seco del fruto, su concentración de aceite, y la proporción de ácidos grasos en el aceite. El contraste entre aplicaciones de temperaturas mayores o menores al ambiente durante períodos largos (114 días) y cortos (30 días) demostraron que tanto la proporción de aceite del fruto como la de ácido oleico en el aceite de fruto entero (mesocarpo + semilla) disminuye al aumentar la temperatura. Si bien en ambas estructuras del fruto la temperatura tuvo un efecto negativo sobre la concentración de aceite, las respuestas a la temperatura de la proporción de ácidos grasos de la semilla y el mesocarpo, medidos en forma separada, difirieron entre sí. Los patrones de respuesta de las proporciones de ácidos grasos en el aceite de semilla mostraron similitudes con las conocidas para especies oleaginosas de semilla como girasol. Por contraste, en el aceite de mesocarpo de olivo la proporción de ácido oleico disminuyó con el aumento de la temperatura, patrón opuesto a lo manifestado en semillas de olivo y en las de oleaginosas anuales. En esta tesis también se evaluó el efecto de la temperatura mínima nocturna sobre el crecimiento de los frutos y la calidad del aceite. Los resultados sugieren que la temperatura mínima nocturna y la amplitud térmica diarias son las dimensiones del régimen térmico diario con los que mejor se asociaron los cambios en el peso seco del fruto, la proporción de aceite y las proporciones de ácidos grasos en el mismo. Los resultados de esta tesis sirven para guiar la selección de sitios de plantación de nuevos olivares basados en los registros térmicos zonales, y para explicar los desajustes de la proporción de ácidos grasos del aceite de oliva producido en el NOA y la normativa del Consejo Oleícola Internacional (COI). Las relaciones funcionales entre las variables respuesta y la temperatura definidas podrán incorporarse en modelos de simulación del rendimiento y calidad que se desarrollen en el futuro. Tomados en conjunto con la tendencia al aumento de la temperatura, producto del calentamiento global, los resultados permitirán estimar la magnitud de los impactos negativos que podrían afectar el rendimiento del cultivo y la calidad del aceite.