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Spontaneous combined rupture of a pelvicalyceal cyst into the collector system and retroperitoneal space during the acquisition of computed tomography scan images: a case report

Marques, Diogo ; Bezerra, Regis Otaviano ; Siqueira, Luiz de Brito; Menezes, Marcos ; Rocha, Manoel de Souza; Cerri, Giovanni Guido
Fonte: Journal of Medical Case Reports 2012, n.6,386,pp 1-4,2012; London Publicador: Journal of Medical Case Reports 2012, n.6,386,pp 1-4,2012; London
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.95%
Abstract Introduction Pelvicalyceal cysts are common findings in autopsies and can manifest with a variety of patterns. These cystic lesions are usually a benign entity with no clinical significance unless they enlarge enough to cause compression of the adjacent collecting system and consequently obstructive uropathy. Few cases of the spontaneous rupture of pelvicalyceal renal cysts have been published and to the best of our knowledge there is no report of a combined rupture to collector system and retroperitoneal space documented during a multiphase computed tomography. Case presentation We report a case of a ‘real-time’ spontaneous rupture of a pelvicalyceal cyst into the collecting system with fistulization into the retroperitoneum. The patient was a 78-year-old Caucasian man with a previous history of renal stones and a large pelvicalyceal renal cyst who was admitted to our Emergency department with acute right flank pain. A multiphase computed tomography was performed and the pre-contrast images demonstrated a right pelvicalyceal renal cyst measuring 12.0 × 6.1cm in the lower pole causing moderate dilation of the upper right renal collection system. In addition, a partially obstructive stone on the left distal ureter with mild left hydronephrosis was noted. The nephrographic phase did not add any new information. The excretory phase (10-minute delay) demonstrated a spontaneous rupture of the cyst into the pelvicalyceal system with posterior fistulization into the retroperitoneal space. Conclusion In this case study we present time-related changes of a rare pelvicalyceal cyst complication...

Desenvolvimento de uma bancada para ensaios de coletores solares de tubos de vidro a vácuo

Manea, Tiago Francisco
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
27.41%
Sistemas de aquecimento de água que utilizam a conversão de energia solar em energia térmica, além de serem um meio fácil e limpo de geração de energia, trazem benefícios econômicos ao país e principalmente a quem os utiliza. O elemento principal destes sistemas, o coletor solar, é objeto de estudo neste trabalho. Coletores planos são amplamente utilizados e possuem uma tecnologia consolidada, porém, um tipo de coletor composto por tubos de vidro, com isolamento a vácuo e superfície absorvedora seletiva vem se tornando uma opção cada vez mais viável economicamente. Com benefícios evidentes em climas de frio mais intenso, estes coletores devem ter seus parâmetros de desempenho térmico determinados segundo procedimentos normativos, para que possam ser dimensionados de forma correta os sistemas de aquecimento que os utilizarem. Este trabalho descreve o desenvolvimento de uma bancada de ensaios construída no Laboratório de Energia Solar da Universidade Federal do Rio Grande do Sul, que tem o intuito de possibilitar o ensaio deste tipo de coletor. Esta bancada contou com uma instrumentação cuidadosamente calibrada e com um dispositivo, desenvolvido neste trabalho, capaz de realizar medidas da diferença de temperatura da água entre as seções de entrada e saída do coletor com uma incerteza inferior a 0...

Otimização exergetica de um sistema coletor-armazenador de calor latente; Exergetic optimization of a collector-storage system of latent heat

Santiago del Rio Oliveira
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/07/2008 PT
Relevância na Pesquisa
37.2%
O objetivo desse trabalho é fazer uma otimização exergética de um sistema térmico de energia solar. Esse sistema é composto por um coletor solar e por um tanque armazenador de água retangular que contém material de mudança de fase distribuído em um conjunto de barras. Esse estudo leva em consideração ambas transferências de calor por condução e convecção para a água no coletor solar, e também o processo de mudança de fase para o PCM no armazenador térmico. Assim, no coletor solar são determinadas a temperatura ótima de saída e vazão mássica ótima da água em função das condições de radiação solar. Além disso, para o tanque armazenador, são determinadas a temperatura ótima de fusão do PCM e o máximo trabalho que pode ser obtido levando em consideração o processo de mudança de fase. O processo de fusão do PCM é analisado por meio de uma solução analítica aproximada. Finalmente, foram feitas uma análise energética e exergética de cada componente do sistema bem como de todo o sistema e foram calculadas eficiências de primeira e segunda lei da termodinâmica. Resultados numéricos de um estudo de caso são apresentados e discutidos; This work deals with the exergetic optimization of a solar thermal energy system. This consists of a solar collector and a rectangular water storage tank that contains a phase change material distributed in an assembly of slabs. The study takes into account both conduction and convection heat transfer modes for water in the solar collector...

Solar thermal collector yield: experimental validation of calculations based on steady-state and quasi-dynamic test methodologies

Horta, Pedro; Carvalho, M. J.; Fischer, S.
Fonte: Laboratório Nacional de Energia e Geologia Publicador: Laboratório Nacional de Energia e Geologia
Tipo: Conferência ou Objeto de Conferência
Publicado em 07/10/2008 ENG
Relevância na Pesquisa
27.41%
The characterization of collector efficiency is the fundamental tool for long term calculation of collector yield. It is, thus, one of the most important inputs in software tools aiming the design of solar thermal systems. Presently two test methodologies are available for characterization of the efficiency of glazed collectors: i) steady state test and ii) quasi-dynamic test, methodologies based in different model approaches to a solar collector, providing different collector efficiency curve parameters and, consequently, imposing different power calculation algorithms. Moreover, Horta et al (2008) demonstrated that the use of the collector efficiency curve derived from steady state test method is not enough for a thorough characterization of the long term performance of a collector. The present work takes into account the introduction of the above referred test methodologies in the European Test Standard for Solar Thermal Collectors, and aims at clarifying how each test results should be used in long term thermal performance calculations. The paper presents a synthesis of the different efficiency parameters provided by each test methodology and corresponding algorithms, applicable in the calculation of delivered power. Application of these algorithms to two days of measured data allows for a comparison of the results obtained with these different methodologies. For validation purposes...

Impact of different internal convection control strategies in a non-evacuated CPC collector performance

Horta, Pedro; Henriques, J.C.C.; Pereira, M. Collares
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2012 ENG
Relevância na Pesquisa
37.37%
Over the last decade the technological advances observed in solar collector materials, namely better spectrally selective absorber coatings and ultra clear glass covers, contribute to performance improvements and translate into higher operational temperature ranges with higher efficiency values. While the use of Evacuated Tube Collectors (ETCs) is becoming widespread in the thermal conversion of solar energy, non-evacuated solar collectors still hold advantages at manufacturing, reliability and/or cost levels, making them interesting and competitive for a large range of applications, in particularly, in temperature ranges up to 80 °C. However, these advantages have not prevented the major drawback of these collectors when compared to ETCs: thermal losses due to internal convection which prevent their general use in the range of operating temperatures up to 150 °C.Insulation, double glazing or selective coatings can be used in non-evacuated collectors to reduce heat losses. To prevent internal convection losses in these solar collectors, different control strategies have been studied, such as the adoption of different inert gases within the collector cavity, physical barriers reducing air flow velocities over the absorber or cover surfaces or the use of concentration. In the present article...

Review of solar thermoelectric energy conversion and analysis of a two cover flat-plate solar collector; Analysis of a two cover flat-plate solar collector

Hasan, Atiya
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 48 p.
ENG
Relevância na Pesquisa
27.44%
The process of solar thermoelectric energy conversion was explored through a review of thermoelectric energy generation and solar collectors. Existing forms of flat plate collectors and solar concentrators were surveyed. A thermal analysis of a common two-cover flat plate solar collector was then performed. The model focused specifically on radiation absorption through the cover system and radiation and convection losses from the absorption plate to determine the parameters that most significantly affect the efficiency of the collector and the overall efficiency of the solar thermoelectric generator. In this case, collector efficiency was measured by the ratio of useable energy to incident solar energy. Overall generator efficiency was measured by power generated per unit area of the collector. It was found that of several parameters, the collector area had the most significant influence on collector efficiency. For the overall efficiency of the generator, the most significant parameter was the ratio of the collector area to the cross-sectional area of the thermoelectric elements (TE). The efficiency of the generator maximized at a ratio of 250:1, with a magnitude of 5.76 W/m2. The analysis exposes some weaknesses of the flat plate collector to show where future designs should focus for improvement.; by Atiya Hasan.; Thesis (S.B.)--Massachusetts Institute of Technology...

Utilização do óleo de pequi como coletor na microflotação de apatita; The use of pequi´s oil as collector in apatite´s microflotation

Silva, Tatiane Carvalho
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Gestão Organizacional (RC); Regional de Catalão (RC) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Gestão Organizacional (RC); Regional de Catalão (RC)
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
37.41%
Pequi is an abundant fruit in the states that have the main phosphate concentration areas in Brazil. Fatty acids are substances that act as collectors in the phosphate flotation, and are present in vegetable oils. Pequi being an oleaginous fruit, its potential as a collector can be valued and explored in the region. In this context, this study aimed to apply the pequi’s oil, extracted from white and yellow pulp of the fruit, in apatite’s froth flotation, verifying its potential to be used as collector. This Brazilian fruit is rich in fatty acids with predominance of oleic and palmitic acids. For the white pulp (outer mesocarp) application, extraction procedures were performed using Soxhlet extractor, and subsequently was executed the separation of the solvent present in the extract. The yellow pulp (inner mesocarp) oil was obtained at Goiânia’s Central Market, and was produced by a specialized company. The pequi’s yellow pulp oil was subjected to chemical characterization, with the determination of its acidity, saponification, iodine and determination of unsaponifiable matter. The verification of this oil performance as collector was performed using microflotation in Hallimond tube, by varying the concentration of the collector and the pH of the solution. The microflotation was performed with samples of pure apatite. The mineral was subjected to chemical characterization and determination of density by pycnometry. Besides pequi’s oil...

Thermal and electrical performance of a concentrating PV/Thermal collector: results from the ANU CHAPS collector

Coventry, J; Franklin, E; Blakers, Andrew W
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Conference paper Formato: 1601658 bytes; 371 bytes; 371 bytes; application/pdf; application/octet-stream; application/octet-stream
EN_AU
Relevância na Pesquisa
37.37%
The combined heat and power solar (CHAPS) collector under development at the ANU is a PV/Thermal collector utilizing parabolic mirrors to concentrate light by a factor of 25-35x. This paper presents some measured results for thermal and electrical output from the CHAPS collector, as well as an overview of the major components of the CHAPS collector.; no

Simulation of a concentrating PV/thermal collector using TRNSYS

Coventry, J
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Conference paper Formato: 1291404 bytes; 366 bytes; application/pdf; application/octet-stream
EN_AU
Relevância na Pesquisa
37.33%
A TRNSYS component (Type 262) has been written to simulate a concentrating PV/Thermal collector. The component is based on a dynamic model of a concentrating PV/Thermal collector, which includes thermal capacitance effects, and detailed equations describing the temperature dependent energy flow between the collector and surroundings. The CHAPS system, a 30x concentration parabolic trough PV/Thermal collector developed at the ANU, has been used to validate the accuracy of the Type 262 TRNSYS component. Results are presented comparing the annual output of a domestic CHAPS system that integrates the Type 262 collector, with a flat plate solar hot water system and a PV array located side-by-side.; no

Estudio del Comportamiento térmico de pavimentos de mezcla bituminosa y análisis de un colector solar asfáltico multicapa; Study of the thermal behaviour of bituminous mix pavements and analysis of a multilayered asphalt solar collector

Pascual Muñoz, Pablo
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Tese de Doutorado
SPA
Relevância na Pesquisa
36.95%
RESUMEN:Esta tesis estudia la utilización de los pavimentos de mezcla bituminosa como medio para captar y almacenar parte de la energía irradiada por el sol a modo de colector asfáltico termosolar. En primer lugar, se analiza experimentalmente el comportamiento térmico de tres tipos diferentes de mezclas bituminosas sometidas a la radiación solar. Con los resultados de estos ensayos se desarrolla y calibra un modelo numérico en diferencias finitas que permite llevar a cabo un análisis de sensibilidad de los parámetros más relevantes del sistema. A continuación, se lleva a cabo un estudio de la relación entre la degradación sufrida por el color de los pavimentos asfálticos y el cambio en su capacidad de almacenamiento de energía. Finalmente, se desarrolla y analiza en laboratorio un nuevo prototipo de colector asfáltico multicapa en el que se ha sustituído la red de tubos utilizada habitualmente como elemento conductor del fluido caloportador por una capa de mezcla asfáltica porosa. Los resultados muestran un excelente rendimiento térmico del prototipo. Sin embargo, estos buenos resultados contrastan con la obtención de unos valores de caudal pequeños que evidencian la necesidad de una mayor investigación en esta tecnología.; ABSTRACT: This thesis studies the use of asphalt pavements for capturing and storing the thermal energy radiated by the sun as asphalt solar collectors. first of all...

Impact of different internal convection control strategies in a non-evacuated CPC collector performance

Horta, Pedro; Henriques, J.C.C.; Collares-Pereira, Manuel
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.33%
Over the last decade the technological advances observed in solar collector materials, namely better spectrally selective absorber coatings and ultra clear glass covers, contribute to performance improvements and translate into higher operational temperature ranges with higher efficiency values. While the use of Evacuated Tube Collectors (ETCs) is becoming widespread in the thermal conversion of solar energy, non-evacuated solar collectors still hold advantages at manufacturing, reliability and/or cost levels, making them interesting and competitive for a large range of applications, in particularly, in temperature ranges up to 80 C. However, these advantages have not prevented the major drawback of these collectors when compared to ETCs: thermal losses due to internal convection which prevent their general use in the range of operating temperatures up to 150 C. Insulation, double glazing or selective coatings can be used in non-evacuated collectors to reduce heat losses. To prevent internal convection losses in these solar collectors, different control strategies have been studied, such as the adoption of different inert gases within the collector cavity, physical barriers reducing air flow velocities over the absorber or cover surfaces or the use of concentration. In the present article...

An oriented-design simplified model for the efficiency of a flat plate solar air collector

LUNA, David; JANNOT, Yves; NADEAU, Jean-Pierre
Fonte: Elsevier Publicador: Elsevier
EN
Relevância na Pesquisa
37.27%
In systems design, suitably adapted physical models are required. Different modelling approaches for a solar air collector were studied in this paper. First, a classical model was produced, based on a linearization of the conservation of energy equations. Its resolution used traditional matrix methods. In order to improve the possibilities for use in design, the behaviour of the collector was next expressed in terms of efficiency. Lastly, simplified models constructed from the results obtained with the classical linearized model, and explicitly including the design variables of the collector, were proposed. These reduced models were then evaluated in terms of Parsimony, Exactness, Precision and Specialisation (PEPS). It was concluded that one of them (D2), using a low number of variables and of equations, is well suited for the design of solar air collector coupled with other sub-systems in more complex devices such as solar kiln with energy storage

Magnesium isotopic analysis of olivine by laser-ablation multi-collector ICP-MS: composition dependent matrix effects and a comparison of the Earth and Moon

Norman, Marc; McCulloch, Malcolm; O'Neill, Hugh; Yaxley, Gregory
Fonte: Royal Society of Chemistry Publicador: Royal Society of Chemistry
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.95%
Magnesium isotopic compositions of olivine were measured by laser-ablation multi-collector ICP-MS using an ArF 193 nm excimer laser. Analytical precision based on replicate analyses of mantle olivine is ∼0.2 permil (2SD). This is about an order of magni

Collector Failures on 350 MHz, 1.2 MW CW Klystrons at the Low Energy Demonstration Accelerator (LEDA)

Rees, D.; Roybal, W.; Bradley, J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 15/08/2000
Relevância na Pesquisa
27.37%
We are currently operating the front end of the accelerator production of tritium (APT) accelerator, a 7 MeV radio frequency quadrapole (RFQ) using three, 1.2 MW CW klystrons. These klystrons are required and designed to dissipate the full beam power in the collector. The klystrons have less than 1500 operational hours. One collector has failed and all collectors are damaged. This paper will discuss the damage and the difficulties in diagnosing the cause. The collector did not critically fail. Tube operation was still possible and the klystron operated up to 70% of full beam power with excellent vacuum. The indication that finally led us to the collector failure was variable emission. This information will be discussed. A hydrophonic system was implemented to diagnose collector heating. The collectors are designed to allow for mixed-phase cooling and with the hydrophonic test equipment we are able to observe: normal, single-phase cooling, mixed-phase cooling, and a hard boil. These data will be presented. The worst case beam profile from a collector heating standpoint is presented. The paper will also discuss the steps taken to halt the collector damage on the remaining 350 MHz klystrons and design changes that are being implemented to correct the problem.; Comment: LINAC2000 conference paper THE12

Role of self-propulsion of marine larvae on their probability of contact with a protruding collector located in a sea current

Zilman, Gregory; Novak, Julia; Liberzon, Alex; Perkol-Finkel, Shimrit; Benayahu, Yehuda
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 07/08/2011
Relevância na Pesquisa
27.48%
Settlement of marine larvae on a substrate is a fundamental problem of marine life. The probability of settlement is one of the quantitative characteristic of the settlement process. The probability of larval contact with a substrate is the upper bound of the probability of settlement. This work addresses the problem of contact probability and contact rate of marine invertebrate larvae with an isolated protruding collector located in an unbounded sea current. There are two common approaches to the problem of contact probability. In one, a collector induces certain cues, which help a larvae find the collector. In such a case, the larva moves towards the collector deliberately, using its navigation and propulsion devices. In the second approach, a larva moves towards a collector as a passive small particle. In this case, the cause of contact of a larva with a collector is a mechanical collision of a small moving body with a large obstacle. We considered a larva which does not know the location of the collector, which does not use its navigation device yet uses its self-propulsion. We mimicked a larva by a tiny self-propelled underwater vehicle, moving in shear flow of a large obstacle. We illustrated our approach by studying contact of a larva of the Bryozoan Bugula neritina with a cylindrical collector. We observed the behavior of this larva in a laboratory flume...

Performance Analysis of a Black Liquid Solar Collector

Trentelman, Jackson
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
27.41%
The performance of a black liquid, sheet flow solar collector has been investigated both analytically and experimentally. In addition, its performance has been compared to that of a baseline collector of the tube and fin design. The black liquid solar collector was predicted to exhibit an instantaneous efficiency improvement of 10-15% over a well designed tube and fin collector. This result was confirmed experimentally. Long term efficiency calculations indicate similar performance improvements over long term use. The major contribution to improved efficiency was found to be the direct absorption process whereby a) the collector efficiency, F’, is unity and b) the effective transmittance-absorptance, (τα) eff’, is increased for most angles of incidence over that of a comparable tube and fin collector. A significant advantage of the proposed collector was found to be reduced cost per unit energy collected since no metals are required in collector fabrication.

Performance of a concentrating photovoltaic/thermal solar collector

Coventry, Joseph
Fonte: Pergamon-Elsevier Ltd Publicador: Pergamon-Elsevier Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.95%
The performance of a parabolic trough photovoltaic/thermal collector with a geometric concentration ratio of 37× is described. Measured results under typical operating conditions show thermal efficiency around 58% and electrical efficiency around 11%, th

Improving emulsion separation: the collector material concept

Morales,C. J.; Riebel,U.; Zavarce,L.; Guzmán,N. M.
Fonte: Latin American applied research Publicador: Latin American applied research
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2010 EN
Relevância na Pesquisa
36.95%
A variety of materials have been used to investigate their applicability as so-called collector materials to improve the destabilization and separation of water in oil emulsions stabilized by a nonionic surfactant. The emulsion destabilization degree was determined by the extent of water and oil separated after centrifugation. The recovery of both phases was strongly dependent on the nature of the material, material/emulsion ratio, particle size, and contact time. By varying conditions, it is possible to increase the separation of water from 0% (without material) up to 95%.

Effect of microemulsified collector on froth flotation of coal

Li,L.; Lu,X.; Qiu,J.; Liu,D.
Fonte: Journal of the Southern African Institute of Mining and Metallurgy Publicador: Journal of the Southern African Institute of Mining and Metallurgy
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2013 EN
Relevância na Pesquisa
37.27%
The performance of microemulsified diesel and conventional diesel collectors in coal flotation was compared by flotation indicators, including combustible recovery, ash content of the clean coal, and the flotation index. An efficient separation with lower dosage was obtained using the microemulsified diesel collector. Under optimum separation conditions, the microemulsion consumption was 100 g/t less compared with diesel. The saving in diesel consumption using the microemulsion reached about 70%, disregarding the consumption of the surfactant and cosurfactant. Frothing tests showed that the frother dosage was decreased by using the microemulsion collector, because of the surfactant and cosurfactant added during preparation. The microemulsified diesel collector is superior to the conventional diesel collector in terms of diesel consumption and separation efficiency, but the selectivity requires further improvement.

Exergy analysis of a flat plate solar collector

Chamoli,Sunil
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
37.2%
In this study, exergetic performance analysis of flat plate solar collector has been carried out analytically. A comprehensive mathematical modelling of thermal performance is simulated using MATLAB simulink and optimal geometrical and thermody-namic parameters are predicted pertaining to optimum performance of the system. The optimization procedure was applied to a typical collector and the optimum design points were extracted. The optimum values of collector inlet temperature, mass flow rate, absorber plate area, and fluid outlet temperature for maximum exergy inflow from the system have been obtained.