Análise da influência dos solutos Zr e Ti sobre as propriedades mecânica, elétrica e de termorresistência de uma liga Al-Cu-Fe-Si destinada a Tx e a Dx de energia elétrica

O contexto energético mundial apresenta um aumento constante do consumo de energia elétrica no último século, desta forma exigindo a pesquisa de novos materiais para a aplicação em cabos e fios condutores de eletricidade. A partir destas demandas por novos materiais, desenvolveu-se uma análise da influência dos solutos zircônio e titânio na modificação de características importantes de uma liga Al-Cu-Fe-Si, destinada a ser o meio condutor de energia elétrica, almejando obter propriedades termorresistentes. Para a realização deste estudo, as ligas foram obtidas por fundição direta em lingoteira metálica em formato “U”, a partir do Al-EC, fixando-se na liga-base os teores de 0,05% Cu, [0,24 a 0,28]% Fe e 0,7% de Si, e em seguida, inserindo-se os teores de 0,26% Zr e 0,26% Ti. O experimento foi dividido em duas etapas, ETAPA A e ETAPA B, respectivamente, com o intuito de se avaliar as características mecânicas, elétricas e estruturais das ligas. Os corpos de prova após laminação a frio (nos diâmetros 2,7; 3,0; 3,8 e 4,0 mm) foram analisados sem tratamento térmico (STT) e com tratamento térmico (CTT): 230 ºC por uma hora, de acordo com o protocolo COPEL, 310 ºC e 390 ºC por uma hora, visando avaliar a ermorresistência em temperaturas mais elevadas, a estabilidade térmica e analisar as microestruturas desenvolvidas em tais tratamentos térmicos (TT). Verificou-se que o Ti tem maior capacidade de refinar o grão em relação ao Zr, que apresenta grãos menos refinados, porém com melhores propriedades físicas e apresentando-se termorresistente.

Análise combinada dos efeitos dos revestimentos nas propriedades de fibras ópticas comerciais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Representação iterativa e folksonomia assistida para repositórios digitais

Information retrieval has been much discussed within Information Science lately. The search for quality information compatible with the users needs became the object of constant research.Using the Internet as a source of dissemination of knowledge has suggested new models of information storage, such as digital repositories, which have been used in academic research as the main form of autoarchiving and disseminating information, but with an information structure that suggests better descriptions of resources and hence better retrieval.Thus the objective is to improve the process of information retrieval, presenting a proposal for a structural model in the context of the semantic web, addressing the use of web 2.0 and web 3.0 in digital repositories, enabling semantic retrieval of information through building a data layer called Iterative Representation.The present study is characterized as descriptive and analytical, based on document analysis, divided into two parts: the first, characterized by direct observation of non-participatory tools that implement digital repositories, as well as digital repositories already instantiated, and the second with scanning feature, which suggests an innovative model for repositories, with the use of structures of knowledge representation and user participation in building a vocabulary domain. The model suggested and proposed ─ Iterative Representation ─ will allow to tailor the digital repositories using Folksonomy and also controlled vocabulary of the field in order to generate a data layer iterative, which allows feedback information, and semantic retrieval of information, through the structural model designed for repositories. The suggested model resulted in the formulation of the thesis that through Iterative Representation it is possible to establish a process of semantic retrieval of information in digital repositories.

Análise comparativa entre a produção de biogás em aterro controlado e variações no potencial elétrico natural por meio de perfilagem geofísica

This work aims to analyze data from a Natural Electric Potential landfill type ditch located in Cordeirópolis (SP). The procedure measures initially involved the assembly and installation of an apparatus cables, sensors and drain geophysical measurements and flow rate of biogas in a ditch later filled by solid waste. Biogas is a product of degradation of organic matter in waste by the action of microorganisms in an anaerobic environment. Its features high methane content in the gas potentially usable as fuel in energy generation systems or steam. The study area is characterized by clayey soil composition change from the diabase sill correlated to the event Serra Geral Formation siltstones overlapping Tatuí with groundwater level site around 50m. The cables were installed vertically in parallel with drain gas manifold, which allowed the collection of data by the technique geophysical logging every 15 days over a period of eight months. For data analysis we used four parameters in the study, the closing time of the ditch, natural electric potential, the flow velocity of biogas and rain. With the tabulated data plots were constructed for each collection day showing values in the range of the cable is in contact with waste (200 cm - 400 cm) and range of the cable in contact with the soil (600 cm - 800 cm). Subsequently graphs were generated with the period of eight months to analyze the data tabulated. A statistical correlation data, which show the influence of rainfall on the production of biogas. The results were satisfactory and demonstrated the feasibility of the research method in studies for the feasibility analysis for the capture of biogas energy

Análise comparativa entre sistemas de resfriamento de injeção de plástico

This study aims to prove the economic feasibility of the installation of mechanical compression chillers on plastic injection molding machines in order to reduce the production cycle time of toothbrush cables in a specific case study. This evidence was confirmed by the comparative analysis of the system replaced and the new system installed. The old system had only one closed loop cooling tower which pumped chilled water to the injection molds, and the new system has the same tower sending cold water to the condensers of individual chillers installed on each injection machine. We conducted an analysis of energy efficiency in each system, showing that in terms of thermal efficiency virtually nothing has changed, but in terms of electricity demand the new system consumes 60.3 kW more. We conducted an analysis of machine productivity for both systems, showing a much higher productivity of the new system due to reduced cycle times caused by the presence of chillers and their greater cooling capacities. Equipped with data such as electricity rates, increases in operating costs and initial investments, the increase in consumption and demand of electricity plus the cycle time reduction were also calculated over so the simple payback 1 year and 2 months was reached

Avaliação de sistemas de pultrudados com diferentes tipos de matrizes para aplicação em cabos condutores

In the last decades it has been observed a substantial developing of the electrical energy demand in the societies all over the World. In consequence the electrical energy distribution companies are increasing the quantity of electrical energy through the electrical energy conductor cables, which had grown the sag in the towers of energy transmission. Furthermore, the construction of more transmission towers brings a lot of troubles due environmental protection laws. In this way, looking forward to increase the quantity of electrical energy transmitted through electrical cables conductors, reduce the need of constructing new transmission towers and the sag in them, we suggest in this work the replace of the traditional core of the conductors cables commonly used, made of steel, by a core made by a composite material, which one is made by carbon fibers pultruded with polymeric resins as matrix. In a order to evaluate if the resins more commonly used in structural composites can be applied as matrix to make possible to use the composite material as a core, we made carbon fibers systems pultruded with epoxy, phenolic and polyester resins as matrix and a mechanic and physic-chemistry characterization was done on the systems by Tensile and Poisson tests, differential sprobe calorimetry (DSC), thermogravimetric analysis (TGA) and Fourier transformed infrared spectroscopy (FTIR), following their correspondents standards

Análise do conforto de aplicadores para terapia estética sob a ótica da ergonomia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Considerações sobre a análise de segunda ordem de estais utilizados em torres metálicas e flares

This work is consideration of an analysis of second-order (nonlinear analysis) applied to e metal towers and flares. The analysis is mainly done using the wind efforts and the weight of the structure. The analysis itself is carried out with the aid of a structural analysis software, SAP2000 where two proposes modeling. The first for the linear effects and the second for the nonlinear effects

Considerações sobre a análise de segunda ordem de estais utilizados em torres metálicas e flares

This work is consideration of an analysis of second-order (nonlinear analysis) applied to e metal towers and flares. The analysis is mainly done using the wind efforts and the weight of the structure. The analysis itself is carried out with the aid of a structural analysis software, SAP2000 where two proposes modeling. The first for the linear effects and the second for the nonlinear effects

Modelo tridimensional em elementos finitos para a análise de cabo umbilical STU submetido ao carregamento de crushing.

Este trabalho desenvolve e apresenta um modelo tridimensional em elementos finitos de um cabo umbilical do tipo STU (Steel Tube Umbilical) utilizado na extração offshore de petróleo. Tal modelo é utilizado para estudar o carregamento de crushing, que é imposto ao cabo umbilical pelas sapatas do tensionador durante o seu lançamento, de modo a obter de forma detalhada a distribuição de tensões nos componentes do núcleo, com foco nos tubos de aço utilizados para o transporte de fluidos. A metodologia empregada no desenvolvimento do modelo é descrita detalhadamente ao longo do trabalho, de forma que possa vir a ser utilizada no estudo de outras configurações de cabos umbilicais. O modelo elaborado é utilizado (i) como paradigma para a validação de um modelo bidimensional, que visa analisar o mesmo problema de forma mais simples e rápida, e (ii) para o estudo do comportamento das tensões nos tubos de aço na região de transição de entrada/saída da sapata. Na comparação entre os modelos bi e tridimensional, o trabalho conclui pela validade do modelo bidimensional na avaliação das tensões nos tubos de aço resultantes do carregamento de crushing, na região central do cabo. O estudo realizado na região de transição de entrada/saída da sapata permitiu verificar que ocorre um aumento dos níveis de tensão nos tubos de aço nessas regiões de transição, com redistribuição do campo de tensões após plastificação.

Sistemas de cálculo, análise e operação virtual: interferências de campos elétricos e magnéticos produzidas por estações radio base de acesso múltiplo por divisão de código em banda larga - WCDMA

In this work it was developed mathematical resolutions taking as parameter maximum intensity values for the interference analysis of electric and magnetic fields and was given two virtual computer system that supports families of CDMA and WCDMA technologies. The first family were developed computational resources to solve electric and magnetic field calculations and power densities in Radio Base stations , with the use of CDMA technology in the 800 MHz band , taking into account the permissible values referenced by the Commission International Protection on non-Ionizing Radiation . The first family is divided into two segments of calculation carried out in virtual operation. In the first segment to compute the interference field radiated by the base station with input information such as radio channel power; Gain antenna; Radio channel number; Operating frequency; Losses in the cable; Attenuation of direction; Minimum Distance; Reflections. Said computing system allows to quickly and without the need of implementing instruments for measurements, meet the following calculated values: Effective Radiated Power; Sector Power Density; Electric field in the sector; Magnetic field in the sector; Magnetic flux density; point of maximum permissible exposure of electric field and power density. The results are shown in charts for clarity of view of power density in the industry, as well as the coverage area definition. The computer module also includes folders specifications antennas, cables and towers used in cellular telephony, the following manufacturers: RFS World, Andrew, Karthein and BRASILSAT. Many are presented "links" network access "Internet" to supplement the cable specifications, antennas, etc. . In the second segment of the first family work with more variables , seeking to perform calculations quickly and safely assisting in obtaining results of radio signal loss produced by ERB . This module displays screens representing propagation systems denominated "A" and "B". By propagating "A" are obtained radio signal attenuation calculations in areas of urban models , dense urban , suburban , and rural open . In reflection calculations are present the reflection coefficients , the standing wave ratio , return loss , the reflected power ratio , as well as the loss of the signal by mismatch impedance. With the spread " B" seek radio signal losses in the survey line and not targeted , the effective area , the power density , the received power , the coverage radius , the conversion levels and the gain conversion systems radiant . The second family of virtual computing system consists of 7 modules of which 5 are geared towards the design of WCDMA and 2 technology for calculation of telephone traffic serving CDMA and WCDMA . It includes a portfolio of radiant systems used on the site. In the virtual operation of the module 1 is compute-: distance frequency reuse, channel capacity with noise and without noise, Doppler frequency, modulation rate and channel efficiency; Module 2 includes computes the cell area, thermal noise, noise power (dB), noise figure, signal to noise ratio, bit of power (dBm); with the module 3 reaches the calculation: breakpoint, processing gain (dB) loss in the space of BTS, noise power (w), chip period and frequency reuse factor. Module 4 scales effective radiated power, sectorization gain, voice activity and load effect. The module 5 performs the calculation processing gain (Hz / bps) bit time, bit energy (Ws). Module 6 deals with the telephone traffic and scales 1: traffic volume, occupancy intensity, average time of occupancy, traffic intensity, calls completed, congestion. Module 7 deals with two telephone traffic and allows calculating call completion and not completed in HMM. Tests were performed on the mobile network performance field for the calculation of data relating to: CINP , CPI , RSRP , RSRQ , EARFCN , Drop Call , Block Call , Pilot , Data Bler , RSCP , Short Call, Long Call and Data Call ; ECIO - Short Call and Long Call , Data Call Troughput . As survey were conducted surveys of electric and magnetic field in an ERB , trying to observe the degree of exposure to non-ionizing radiation they are exposed to the general public and occupational element. The results were compared to permissible values for health endorsed by the ICNIRP and the CENELEC .

Desenvolvimento de uma bancada para a realização de ensaios de auto-amortecimento em cabos condutores de energia elétrica

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2015.

Modelagem e análise de um dispositivo mitigador de flecha para linhas de transmissão de energia elétrica baseado em ligas com memória de forma

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2016.

Aplicação do escore MELD em pacientes submetidos a transplante de fígado: análise retrospectiva da sobrevida e dos fatores preditivos a curto e longo prazo

BACKGROUND: The model for end-stage liver disease (MELD) was developed to predict short-term mortality in patients with cirrhosis. There are few reports studying the correlation between MELD and long-term posttransplantation survival. AIM: To assess the value of pretransplant MELD in the prediction of posttransplant survival. METHODS: The adult patients (age >18 years) who underwent liver transplantation were examined in a retrospective longitudinal cohort of patients, through the prospective data base. We excluded acute liver failure, retransplantation and reduced or split-livers. The liver donors were evaluated according to: age, sex, weight, creatinine, bilirubin, sodium, aspartate aminotransferase, personal antecedents, brain death cause, steatosis, expanded criteria donor number and index donor risk. The recipients' data were: sex, age, weight, chronic hepatic disease, Child-Turcotte-Pugh points, pretransplant and initial MELD score, pretransplant creatinine clearance, sodium, cold and warm ischemia times, hospital length of stay, blood requirements, and alanine aminotransferase (ALT >1,000 UI/L = liver dysfunction). The Kaplan-Meier method with the log-rank test was used for the univariable analyses of posttransplant patient survival. For the multivariable analyses the Cox proportional hazard regression method with the stepwise procedure was used with stratifying sodium and MELD as variables. ROC curve was used to define area under the curve for MELD and Child-Turcotte-Pugh. RESULTS: A total of 232 patients with 10 years follow up were available. The MELD cutoff was 20 and Child-Turcotte-Pugh cutoff was 11.5. For MELD score > 20, the risk factors for death were: red cell requirements, liver dysfunction and donor's sodium. For the patients with hyponatremia the risk factors were: negative delta-MELD score, red cell requirements, liver dysfunction and donor's sodium. The regression univariated analyses came up with the following risk factors for death: score MELD > 25, blood requirements, recipient creatinine clearance pretransplant and age donor >50. After stepwise analyses, only red cell requirement was predictive. Patients with MELD score < 25 had a 68.86%, 50,44% and 41,50% chance for 1, 5 and 10-year survival and > 25 were 39.13%, 29.81% and 22.36% respectively. Patients without hyponatremia were 65.16%, 50.28% and 41,98% and with hyponatremia 44.44%, 34.28% and 28.57% respectively. Patients with IDR > 1.7 showed 53.7%, 27.71% and 13.85% and index donor risk <1.7 was 63.62%, 51.4% and 44.08%, respectively. Age donor > 50 years showed 38.4%, 26.21% and 13.1% and age donor <50 years showed 65.58%, 26.21% and 13.1%. Association with delta-MELD score did not show any significant difference. Expanded criteria donors were associated with primary non-function and severe liver dysfunction. Predictive factors for death were blood requirements, hyponatremia, liver dysfunction and donor's sodium. CONCLUSION: In conclusion MELD over 25, recipient's hyponatremia, blood requirements, donor's sodium were associated with poor survival.

Conseqüências da análise incorreta de experimentos blocados

Errors are always present in experimental measurements so, it is important to identify them and understand how they affect the results of experiments. Statistics suggest that the execution of experiments should follow random order, but unfortunately the complete randomization of experiments is not always viable for practical reasons. One possible simplification is blocked experiments within which the levels of certain factors are maintained fixed while the levels of others are randomized. However this has a cost. Although the experimental part is simplified, the statistical analysis becomes more complex.