1000 resultados para Cargas térmicas


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Although already to exist alternative technique and economically viable for destination of used tires, quantitative data on properties of constructive elements that use the rubber waste as aggregate still are restricted. In the present work, the waste proceeding from industry of retreading as material for manufacture of composite destined to the production of constructive elements was considered. Mechanical and thermal properties of mortar had been analyzed Portland cement with addition of waste without treatment, in the ratios of 10%, 20% and 30% in mass in relation to the mass of the cement, substituting the aggregate in the trace in mortar 1:5 mass cement and sand. The size of the used residue varied between 0,30mm and 4,8mm (passing in the bolter 4,8mm and being restrained in the one of 0,30mm), being it in the formats fibers and granular. The influences of the size and the percentage of residue added to the mortar (in substitution to the aggregate) in the thermal and mechanical properties had been considered. Assays of body-of-test in thestates had been become fullfilled cool (consistency index) and hardened (absorption of water for capillarity, strength the compression, traction and strength flexural). The work is centralized in the problem of the relation thermal performance /strength mechanics of used constructive systems in regions of low latitudes (Been of the Piauí), characterized for raised indices of solar radiation.

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La mampostería confinada es uno de los sistemas constructivos más utilizados en el mundo. El estudio de su comportamiento ante cargas cíclicas es de vital importancia, ya que permite predecir su respuesta ante este tipo de solicitaciones. En este estudio se caracterizaron las respuestas asociadas al comportamiento cíclico y la inclusión en el rango inelástico de los muros de mampostería confinada, de bloques huecos de concreto.

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Campesinos con cargas de café para la venta. Lugar sin identificar. C. 1980.

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Cargas de café transportadas en tren. San Quintín. C. 1936.

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Este trabalho consiste na elaboração do Relatório Final do Estágio Curricular, realizado como parte integrante e conclusiva do curso de Mestrado em Treino Desportivo pela Faculdade de Motricidade Humana. O Estágio desenvolveu-se no Real Sport Clube, nomeadamente no escalão de Juniores A na época de 2014/2015 tendo como objetivos favorecer a integração e consolidação, no contexto da prática, os conhecimentos teóricos adquiridos ao longo do curso. O presente relatório está estruturado em diferentes capítulos, ao longo dos quais se apresentam as atividades desenvolvidas durante o Estágio Curricular. O propósito é descrever e refletir sobre as atividades desenvolvidas ao longo da época, pretendendo-se realizar uma avaliação de todo o trabalho desenvolvido e os conhecimentos dele derivado, ao descrever e analisar criticamente as duas dimensões. O relatório tem inicio com uma revisão da literatura que suporta a prática profissional, composta por três áreas: a área 1 diz respeito à organização e gestão do processo de treino e competição, onde são abordadas as tarefas relativas à conceção dos ciclos de treino, condução das sessões e controlo da competição bem como algumas informações relativas ao plantel de Juniores A do RSC. Na área 2 é apresentado um estudo de investigação realizado com recurso a dispositivos GPS que nos apresenta resultados relativos às distâncias percorridas pelos diferentes atletas em jogos oficiais e por último, a área 3 ilustra os dois eventos realizados direcionados para a formação continua dos treinadores de futebol. O Estágio Curricular mostra-se, neste sentido, uma ótima oportunidade de aprendizagem e promotor da aquisição e desenvolvimento de competências profissionais e pessoais, de atitudes e resolução de problemas pedagógicos, por forma a constituir o ponto de partida para uma futura integração no mercado de trabalho.

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La operación de un sistema eléctrico debe cumplir con aspectos de economía, y de seguridad. Un aspecto importante, es la propensión que tienen los circuitos utilizados por las compañías eléctricas a las fluctuaciones en la tensión eléctrica cuando alimentan cargas de gran tamaño. Estas fluctuaciones momentáneas en la magnitud de la tensión suministrada son probablemente los problemas de calidad de la energía más importantes. Sin embargo, los usuarios industriales con servicio de suministro eléctrico exclusivo son más bien la excepción que la regla. En consecuencia, los niveles crecientes de las fluctuaciones de tensión producidos por la operación de cargas cíclicas de tamaños considerables utilizadas por algunos usuarios, se proyectan como una fuente progresiva de deterioro de la calidad de la energía no solo en las instalaciones de los usuarios que las producen sino también en instalaciones vecinas alimentadas por la misma línea. En este documento se propone una metodología para caracterizar los fenómenos electromagnéticos que se presentan en sistemas eléctricos industriales débiles, para establecer un criterio para diagnosticar incompatibilidades entre el sistema eléctrico de suministro y la carga.

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This employment has the function the utilization of mango seeds Tommy Atkins, like starch source to obtain biopolymers and fibers source and nanowhiskers cellulose also, that will be use like reinforcing fillers in micro and nanobiocomposites polymeric. The fibers in natura removed from tegument mango seed were characterized, as weel as the treated fibers and nanowhiskers of cellulose extracted from them. The starch extracted from seed s almond showed a good performance (32%) and a high purity. The chemicals analyzes, of crystallinity and morphological of the fibers in natura, treated fibers and nanowhiskers of cellulose confirmed the efficacy of the chemical treatement performed to remove amorphous constituents (hemicellulose and lignina). The thermoplastic starch (TPS) obtained from two sources, corn starch and starchy material mango, was produced in a twin screw extruder with compositon mass of 62,5% of starch, 9,4% of water and 28,1% of glycerol. The starch material mango was the main objective of this work for the production of biodegradable materials, and the starch corn was utilized during the production stage to evaluate the processability of the starch and use as parameter for comparison, according of being a conventional source for obtaining conventional comercial starch. The incorporation of fibers (6% in mass) and nanowhiskers cellulose (1% in mass) in matrix of TPS to obtain composite and nanocomposite, respectively, it was performed in single screw extruder. The biocomposites and bionanocomposites polymeric were obtained and the TPS from starchy material mango presented better results of thermal and mechanicals properties when compared to TPS corn starch. Concludes that the sediment generated of the agroindustrial processing mango used presents potencial to producing of biodegradables materials

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Epoxy based nanocomposites with 1 wt % and 3 wt % of nanographite were processed by high shear mixing. The nanographite was obtained by chemical (acid intercalation), thermal (microwave expansion) and mechanical (ultrasonic exfoliation) treatments. The mechanical, electrical and thermal behavior of the nanocomposites was determined and evaluated as a function of the percentage of reinforcement. According to the experimental results, the electrical conductivity of epoxy was not altered by the addition of nanographite in the contents evaluated. However, based on the mechanical tests, nanocomposites with addition of 1 wt.% and 3 wt.% of nanographite showed increase in tensile strength of 16,62 % and 3,20 %, respectively, compared to the neat polymer. The smaller increase in mechanical strength of the nanocomposite with 3 wt.% of nanographite was related to the formation of agglomerates. The addition of 1 wt.% and 3 wt.% of nanographite also resulted in a decrease of 6,25 % and 17,60 %, respectively, in the relative density of the material. Thus, the specific strength of the nanocomposites was approximately 33,33 % greater when compared to the neat polymer. The addition of 1 wt.% and 3 wt.% of nanographite in the material increased the mean values of thermal conductivity in 28,33 % and 132,62 %, respectively, combined with a reduction of 26,11 % and 49,80 % in volumetric thermal capacity, respectively. In summary, it has been determined that an addition of nanographite of the order of 1 wt.% and 3 wt.% produced notable elevations in specific strength and thermal conductivity of epoxy

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A infuência da temperatura no desenvolvimento dos insetos é fundamental para a tomada de decisão relacionada à estratégia de controle biológico de pragas. Este trabalho teve por objetivo avaliar a necessidades de graus-dias acumulados entre a oviposição e a eclosão de adultos do psilídeo-de-concha Glycaspis brimblecombei (Hemiptera: Psillydae) em resposta às temperaturas máxima e mínima diárias, observadas em condições de sala de criação do Laboratório de Quarentena ?Costa Lima? da Embrapa Meio Ambiente, em Jaguariúna-SP. Três gaiolas com a mesma quantidade inicial de adultos (preservadas a razão fêmea: macho de 1,06) foram monitoradas até o aparecimento da primeira geração e mortalidade total dos adultos introduzidos. Durante todo o período foram registradas as temperaturas máxima e mínima (em ºC) e a umidade relativa (em %) diárias. Posteriormente foram realizados os cálculos dos graus-dias pelo método da senóide horizontal, considerando a temperatura base de desenvolvimento do inseto de 9,26 ºC . Os cálculos foram realizados utilizando programa eletrônico da Universidade da Califórnia - Davis (UC-IPM). Como resultado, obteve-se uma necessidade média de 377,49 ± 16,09 GD acumulados entre a oviposição e a eclosão de adultos do inseto, bem como de 350,40 ± 18,62 GD para atingir a morte total de todos os adultos introduzidos.

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The preparation of cement slurries for offshore well cementing involves mixing all solid components to be added to the mixing water on the platform. The aim of this work was to study the formulation of pre-prepared dry mixtures, or grouts, for offshore oilwell cementing. The addition of mineral fillers in the strength of lightweight grouts applied for depths down to 400 m under water depths of 500 m was investigated. Lightweight materials and fine aggregates were selected. For the choice of starting materials, a study of the pozzolanic activity of low-cost fillers such as porcelain tile residue, microsilica and diatomaceous earth was carried out by X-ray diffraction and mechanical strength tests. Hardened grouts containing porcelain tile residue and microsilica depicted high strength at early ages. Based on such preliminary investigation, a study of the mechanical strength of grouts with density 1.74 g/cm3 (14.5 lb/gal) cured initially at 27 °C was performed using cement, microsilica, porcelain tile residue and an anti-foaming agent. The results showed that the mixture containing 7% of porcelain tile residue and 7% of microsilica was the one with the highest compressive strength after curing for 24 hours. This composition was chosen to be studied and adapted for offshore conditions based on testes performed at 4 °C. The grout containing cement, 7% of porcelain tile residue, 7% of active silica and admixtures (CaCl2), anti-foaming and dispersant resulted satisfactory rheology and mechanical strength after curing for 24 hours of curing

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The use of technology to protect and produce vegetables and ornamental plants was developed over several adaptation phases that supported the demand for quality and amount of products. These developments also reduced production costs and climate damage to the crops. Many of these adaptations were carried out by farmers on their own initiative, using different materials and devices to solve their problems. This study was carried out at Agricultural Engineering College - Campinas University/UNICAMP, from December 2002 to January 2003, with the objective of evaluating the deformations of the constructive system of bamboo structure for greenhouses, submitted to different spacing among columns, and different vertical strains. It was tested the use of beams and columns built with bamboo stems from the specie Bambusa tuldoides Munro. The beams and columns were tied together with plastic spacing parts, specially designed to facilitate and standardize the construction of the building, providing more resistance and stability. Three column spaces (2.0, 2.5 and 3.0 m) were evaluated under different load strains. The best result was obtained with a spacing of 2.5 m.

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The spouted and fluidized bed technologies are usually employed in operations of drying, coating and granulation of particles by the chemical and pharmaceutical industries. The use of these techniques in agronomy is limited to the treatment of some species of seeds. In this work, the objective was to analyse the fluid-dynamics of fluidized and spouted beds when broccoli (Brassica oleracea L. var. Italica) seeds are used and also to verify the influence on seed germination after 60 min of seed exposition to spouting or fluidization, at room temperature. The fluid-dynamics was defined by the measurements of the bed pressure drop as a function of the air flow rate for different seeds loads. The experimental conditions were based on the physical properties of the seeds and were limited by the apparatus dimensions. The cone-cylindrical bed was constructed in plexyglass to permit flow visualization. The values of the parameters: maximum pressure drop, minimum spouting flow rate and pressure drop, and stable spout pressure drop were experimentally obtained from the fluid-dynamic analysis and were compared with the values calculated by empirical equations found in the literature. The same procedure was carried out with the fluidized bed and the important parameters for this regime were the air velocity and the bed pressure drop at minimum fluidization. The analysis of seed germination indicated that no damage was caused to the seeds by the spout or fluidization processes.

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Handball is a sport that demands endurance associated with fast and powerful actions such as jumps, blocks, sprints and throws. The aim of this study was to evaluate the effects of a 38-week systematic physical training applied to a women's under 21 handball team on upper and lower limb power, 30m sprints speed and endurance. The periodization applied was an adaptation of the Verkhoshansky theory, and aimed at two performance peaks during the season with six data collections. The median and range values for three kg medicine ball throwing was: 2.98m (2.15-3.50); 2.84m (2.43-3.20); 2.90m (2.60-3.38); 3.10 (2.83-3.81); 2.84 (2.55-3.57) and 3.34 (2.93-3.83). Regarding the three-pass running test: 5.60m (4.93-6.58); 5.37m (5.04-6.38); 5.36m (4.93-6.12); 5.65m (4.80-6.78); 5.63m (5.00-6.40) and 5.83m (5.14-6.05). Regarding the 30-m sprint test: 5.8m/s (5.45-6.44); 6,64 m/s (6,24-7,09); 5.65m/s (5.17-5.95); (there was not IV moment for this test); 6.19 m/s (5.57-6.26) and 5.83 (5.14-6.05).Regarding the 30-m sprint endurance test until 10% decrease: 4 sprints (4-6); 5 sprints (4-9); 4,5 sprints (4-16); (there was not IV moment for this test); 6 sprints (4-12) and 5 sprints (4-5). Significant differences (p<0.05) were observed in three kg medicine ball throwing and three-pass running tests at least in one of the performance peak planned, with no significant differences in 30-m sprint speed or endurance tests. The applied physical training was efficient at improving the specific physical fitness in the performance peaks, as well as giving support for better physical training adjustment for the upcoming season.