999 resultados para porcentagem
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The current study presents the characteristics of self-efficacy of students of Administration course, who work and do not work. The study was conducted through a field research, descriptive, addressed quantitatively using statistical procedures. Was studied a population composed of 394 students distributed in three Higher Education Institutions, in the metropolitan region of Belém, in the State of Pará. The sampling was not probabilistic by accessibility, with a sample of 254 subjects. The instrument for data collection was a questionnaire composed of a set of questions divided into three sections: the first related to sociodemographic data, the second section was built to identify the work situation of the respondent and the third section was built with issues related to General Perceived Self-Efficacy Scale proposed by Schwarzer and Jerusalem (1999). Sociodemographic data were processed using methods of descriptive statistics. This procedure allowed characterizing the subjects of the sample. To identify the work situation, the analysis of frequency and percentage was used, which allowed to classify in percentage, the respondents who worked and those that did not work, and the data related to the scale of self-efficacy were processed quantitatively by the method of multivariate statistics using the software of program Statistical Package for Social Sciences for Windows - SPSS, version 17 from the process of Exploratory Factor Analysis. This procedure allowed characterizing the students who worked and the students who did not worked. The results were discussed based on Social Cognitive Theory from the construct of self-efficacy of Albert Bandura (1977). The study results showed a young sample, composed the majority of single women with work experience, and indicated that the characteristics of self-efficacy of students who work and students who do not work are different. The self-efficacy beliefs of students who do not work are based on psychological expectations, whereas the students who work demonstrated that their efficacy beliefs are sustained by previous experiences. A student who does not work proved to be reliant in their abilities to achieve a successful performance in their activities, believing it to be easy to achieve your goals and to face difficult situations at work, simply by invest a necessary effort and trust in their abilities. One who has experience working proved to be reliant in their abilities to conduct courses of action, although know that it is not easy to achieve your goals, and in unexpected situations showed its ability to solve difficult problems
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This work studied the immiscible blend of elastomeric poly(methyl methacrylate) (PMMA) with poly(ethylene terephthalate) (PET) bottle grade with and without the use of compatibilizer agent, poly(methyl methacrylate-co-glycidyl methacrylate - co-ethyl acrylate) (MGE). The characterizations of torque rheometry, melt flow index measurement (MFI), measuring the density and the degree of cristallinity by pycnometry, tensile testing, method of work essential fracture (EWF), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were performed in pure polymer and blends PMMA/PET. The rheological results showed evidence of signs of chemical reaction between the epoxy group MGE with the end groups of the PET chains and also to the elastomeric phase of PMMA. The increase in the concentration of PET reduced torque and adding MGE increased the torque of the blend of PMMA/PET. The results of the MFI also show that elastomeric PMMA showed lower flow and thus higher viscosity than PET. In the results of picnometry observed that increasing the percentage of PET resulted in an increase in density and degree crystallinity of the blends PMMA/PET. The tensile test showed that increasing the percentage of PET resulted in an increase in ultimate strength and elastic modulus and decrease in elongation at break. However, in the phase inversion, where the blend showed evidence of a co-continuous morphology and also, with 30% PET dispersed phase and compatibilized with 5% MGE, there were significant results elongation at break compared to elastomeric PMMA. The applicability of the method of essential work of fracture was shown to be possible for most formulations. And it was observed that with increasing elastomeric PMMA in the formulations of the blends there was an improvement in specific amounts of essential work of fracture (We) and a decrease in the values of specific non-essential work of fracture (βWp)
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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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The development of new materials to fill the demand of technological advances is a challenge for many researchers around the world. Strategies such as making blends and composites are promising alternatives to produce materials with different properties from those found in conventional polymers. The objective of this study is to evaluate the effect of adding the copolymer poly(ethylene methyl acrylate) (EMA) and cotton linter fibers (LB) on the properties of recycled poly(ethylene terephthalate) (PETrec) by the development of PETrec/EMA blend and PETrec/EMA/LB blend composite. In order to improve the properties of these materials were added as compatibilizers: Ethylene - methyl acrylate - glycidyl methacrylate terpolymer (EMA-GMA) and maleic anhydride grafted polyethylene (PE-g-MA). The samples were produced using a single screw extruder and then injection molded. The obtained materials were characterized by thermogravimetry (TG), melt flow index (MFI) mensurements, torque rheometry, pycnometry to determinate the density, tensile testing and scanning electron microscopy (SEM). The rheological results showed that the addition of the EMA copolymer increased the viscosity of the blend and LB reduces the viscosity of the blend composite. SEM analysis of the binary blend showed poor interfacial adhesion between the PETrec matrix and the EMA dispersed phase, as well as the blend composite of PETrec/EMA/LB also observed low adhesion with the LB fiber. The tensile tests showed that the increase of EMA percentage decreased the tensile strength and the Young s modulus, also lower EMA percentage samples had increased the elongation at break. The blend composite showed an increase in the tensile strength and in the Young`s modulus, and a decrease in the elongation at break. The blend formulations with lower EMA percentages showed better mechanical properties that agree with the particle size analysis which showed that these formulations presented a smaller diameter of the dispersed phase. The blend composite mechanical tests showed that this material is stronger and stiffer than the blend PETrec/EMA, whose properties have been reduced due to the presence of EMA rubbery phase. The use of EMA-GMA was effective in reducing the particle size of the EMA dispersed phase in the PETrec/EMA blend and PE-g-MA showed evidences of reaction with LB and physical mixture with the EMA
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The gas migration during the cementing of wells is one of the main problems of oil wells engineering. Its occurrence can cause severe problems since shortly to loss of control of the well after cementation. Recently, 20/04/2010 In an accident of major proportions in the Gulf of Mexico, among other factors, faulty cementing operation provided the gas migration, causing the accident, in which 11 people died and 17 were injured occurred. Besides the serious consequences that can be caused by gas migration, remediation of the problem, which is made by injecting cement in damaged areas, usually involves additional costs and is not always effective. Therefore, preventing gas migration to be preferred. Some methods are used to prevent the migration of the pressurized gas as the annular space, application of pressure pulses, reducing the height of the cement column compressible cement pastes of low permeability, pastes and to control free filtered water, and binders of thixotropic cement expandable and flexible. Thus, the cement pastes used to prevent gas migration must meet the maximum these methods. Thus, this study aimed to formulate a cement paste to prevent gas migration, using the expanded vermiculite, and evaluate the behavior of the folder trials necessary for use in oil wells. Free water content, rheological properties, compressive strength, loss of liquid phase sedimentation of solids, specific weight, thickening time and gas migration: The following tests were performed. The results show that meets the specifications paste formulated for use in oil wells and the use of expanded vermiculite contribute to the absorption of free water, thixotropy and low density. The absorption of free water is proven to result in zero percentage test free water content, thixotropy is observed with the high value of the initial gel strength (Gi) in testing rheological properties and low density is proven in test weight specific
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In the present study we elaborated algorithms by using concepts from percolation theory which analyze the connectivity conditions in geological models of petroleum reservoirs. From the petrophysical parameters such as permeability, porosity, transmittivity and others, which may be generated by any statistical process, it is possible to determine the portion of the model with more connected cells, what the interconnected wells are, and the critical path between injector and source wells. This allows to classify the reservoir according to the modeled petrophysical parameters. This also make it possible to determine the percentage of the reservoir to which each well is connected. Generally, the connected regions and the respective minima and/or maxima in the occurrence of the petrophysical parameters studied constitute a good manner to characterize a reservoir volumetrically. Therefore, the algorithms allow to optimize the positioning of wells, offering a preview of the general conditions of the given model s connectivity. The intent is not to evaluate geological models, but to show how to interpret the deposits, how their petrophysical characteristics are spatially distributed, and how the connections between the several parts of the system are resolved, showing their critical paths and backbones. The execution of these algorithms allows us to know the properties of the model s connectivity before the work on reservoir flux simulation is started
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Como os recursos de hidrocarbonetos convencionais estão se esgotando, a crescente demanda mundial por energia impulsiona a indústria do petróleo para desenvolver mais reservatórios não convencionais. Os recursos mundiais de betume e óleo pesado são estimados em 5,6 trilhões de barris, dos quais 80% estão localizados na Venezuela, Canadá e EUA. Um dos métodos para explorar estes hidrocarbonetos é o processo de drenagem gravitacional assistido com injeção de vapor e solvente (ES-SAGD Expanding Solvent Steam Assisted Gravity Drainage). Neste processo são utilizados dois poços horizontais paralelos e situados verticalmente um acima do outro, um produtor na base do reservatório e um injetor de vapor e solvente no topo do reservatório. Este processo é composto por um método térmico (injeção de vapor) e um método miscível (injeção de solvente) com a finalidade de causar a redução das tensões interfaciais e da viscosidade do óleo ou betume. O objetivo deste estudo é analisar a sensibilidade de alguns parâmetros operacionais, tais como: tipo de solvente injetado, qualidade do vapor, distância vertical entre os poços, porcentagem de solvente injetado e vazão de injeção de vapor sobre o fator de recuperação para 5, 10 e 15 anos. Os estudos foram realizados através de simulações concretizadas no módulo STARS (Steam Thermal, and Advanced Processes Reservoir Simulator) do programa da CMG (Computer Modelling Group), versão 2010.10, onde as interações entre os parâmetros operacionais, estudados em um modelo homogêneo com características de reservatórios semelhantes aos encontrados no Nordeste Brasileiro, foram observadas. Os resultados obtidos neste estudo mostraram que os melhores fatores de recuperação ocorreram para níveis máximos do percentual de solvente injetado e da distância vertical entre os poços. Observou-se também que o processo será rentável dependendo do tipo e do valor do solvente injetado
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Nowadays, most of the hydrocarbon reserves in the world are in the form of heavy oil, ultra - heavy or bitumen. For the extraction and production of this resource is required to implement new technologies. One of the promising processes for the recovery of this oil is the Expanding Solvent Steam Assisted Gravity Drainage (ES-SAGD) which uses two parallel horizontal wells, where the injection well is situated vertically above the production well. The completion of the process occurs upon injection of a hydrocarbon additive at low concentration in conjunction with steam. The steam adds heat to reduce the viscosity of the oil and solvent aids in reducing the interfacial tension between oil/ solvent. The main force acting in this process is the gravitational and the heat transfer takes place by conduction, convection and latent heat of steam. In this study was used the discretized wellbore model, where the well is discretized in the same way that the reservoir and each section of the well treated as a block of grid, with interblock connection with the reservoir. This study aims to analyze the influence of the pressure drop and heat along the injection well in the ES-SAGD process. The model used for the study is a homogeneous reservoir, semi synthetic with characteristics of the Brazilian Northeast and numerical simulations were performed using the STARS thermal simulator from CMG (Computer Modelling Group). The operational parameters analyzed were: percentage of solvent injected, the flow of steam injection, vertical distance between the wells and steam quality. All of them were significant in oil recovery factor positively influencing this. The results showed that, for all cases analyzed, the model considers the pressure drop has cumulative production of oil below its respective model that disregards such loss. This difference is more pronounced the lower the value of the flow of steam injection
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Objetivou-se estudar as características quantitativas da carcaça de 36 bubalinos (12 Murrah 12 Jafarabadi e 12 Mediterrâneo), com idade média de 18 meses e peso vivo inicial de 330 kg, terminados em confinamento. Os 12 animais de cada grupo genético foram divididos aleatoriamente em três subgrupos de quatro animais e submetidos aos seguintes tratamentos: Maturidade 1: 400 kg PV ao abate; Maturidade 2: 450 kg PV ao abate; Maturidade 3: 500 kg PV ao abate. Durante o experimento, uma ração única, em que 50% da MS foi composta por volumoso, foi fornecida, ad libitum, para todos os animais. Após os abates pré-fixados, determinou-se o peso corporal vazio (PCVZ) dos animais pelo somatório das partes integrantes do corpo. Não houve diferença entre grupos genéticos e maturidades, em relação à porcentagem dos cortes dianteiro, paleta, traseiro total e alcatra completa. O rendimento de traseiro especial foi maior nos animais abatidos aos 400 kg PV e menor naqueles com 500 kg PV, enquanto o dos animais com 450 kg PV não diferiu dos demais. O rendimento de ponta-de-agulha, por sua vez, foi maior nos animais com 500 kg PV e menor nos com 400 kg PV. Os valores observados nesses dois pesos de abate não diferiram do obtido nos animais com 450 kg. A produção de carne a partir das raças Murrah, Jafarabadi e Mediterrâneo criadas no Brasil não difere quanto aos rendimentos de carcaça, traseiro, dianteiro e dos principais cortes básicos de interesse comercial.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Radiobiocomplexes are used to obtain images in nuclear medicine and employed in basic research. Blood constituents labeled with technetium-99m (99mTc) have also been employed as radiobiocomplexes and used also experimental model for evaluation of the biological effects of natural or synthetic drugs. The analysis of the morphology and the morphometrics parameters (perimeter/área ratio) can be used to evaluate the effects of drugs upon the structure of the membrane of red blood cells. Cinnamomum zeylanicum (cinnamon) is a spice used as herbal medicine to treat diseases. The aim of this study was to evaluate the effect of in vitro and in vivo treatment with an aqueous cinnamon extract on the labeling of blood constituents with 99mTc and on the morphology of red blood cells from Wistar rats. In the in vitro treatment, isolated blood sample from animals were incubated with cinnamon extract. In the in vivo treatment, blood samples were also withdrawn from animals treated with cinnamon extract. In both cases, the radiolabeling of blood constituents was done. The morphological analysis of red blood cells was also done. As control, blood or animals treated with NaCl 0.9%. The data obtained on the labeling of blood constituents with 99mTc experiments indicated that the in vitro treatment with cinnamon extract was capable to decrease signiicantly (p<0.05) the percentage of radioactivity in cellular compartments and on the fixation of cellular and plasma proteins. These effects were not observed on the in vivo treatment. The results obtained for the morphology of red blood cells suggest that the in vitro and in vivo treatments did not alter the morphology and the perimeter/area ratio. The in vitro treatment with aqueous cinnamon extract could affect the membrane structures related with the oxidation status of the stannous ion pertechnetate ion, altering the labeling of blood constituentes with 99mTc. This study was a multidisciplinary experimental research. It was developed with the contribution of the different Departments and Services of the Hospital Universitário Pedro Ernesto of the Universidade do Estado do Rio de Janeiro
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It is a Cross-sectional and multi-disciplinary study whose population selection was made by department of human resources (composed by a Manager, an Oncologist and a Psychologist) from the hospital where this research was realized. They also collaborated with important information about the work of that professionals in the hospital. We also counted on a Statistic who made study design calculating the sample and analyzing data. This research issued Evaluating health professionals anxiety levels who care for cancer terminally ill and their feelings about that work as well as identifying the factors which have influence on it. 100 health professionals from the Hospital which is a reference on cancer caring in Brazil situated in the city of Natal, state of Rio Grande do Norte, participated of this research. There was a sample loss of 21%. Data were collected through a questionnaire and State-Trait Anxiety Inventory (STAI). Results showed that 15% of the professionals have low State Anxiety levels, 70% Medium State Anxiety levels and 15% high State anxiety levels. The Number of Patients and Working in another Institution have interfered in the anxiety levels. Doctors and Nursing Assistants and Technicians have got the highest high State Anxiety percentage (25%). 73% of them declare to feel some sort of different behavior and/or feelings in caring for terminally ill. The most remarkable professionals feelings were Suffering and Sadness, and Terminally ill Children was the most difficult age group to care for. We conclude that work overload and having more than one job can interfere in professional stress levels and anxiety. Dealing with terminally ill, specially children one, can cause on the professionals psychological suffering. It s recommended the development of supporting and training strategies to reduce and/or to prevent Stress and Anxiety high levels
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Conselho Nacional de Desenvolvimento Científico e Tecnológico
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Artemisia vulgaris (AV) is an antihelmintic and antimalarial drug; Aloe vera(babosa) acts as antidiabetic, laxative and anti-inflammatory; Benznidazole (BZ) is a trypanocidal of Trypanosoma cruzi (TC). Technetium-99m (99mTc) has been used in nuclear medicine to obtain diagnostic images. This study evaluated the plant effects in TC parasitemia and in the biodistribution of 99mTc in mice. Twenty mice were infected by TC. At the peak of parasitemia, 5 mice received babosa; 5 received AV and 5 received BZ. The parasitemia was determined in 0, 2, 4 and 6 h of drugs administration. Five infected mice without drugs, 5 mice without TC and the group treated with AV, received 99mTc. The radioactivity was calculated. Infected mice that received babosa reduced significantly (p<0.05) the parasitemia. The percentage of activity (%ATI) decreased significantly in the AV group. These results indicate that babosa possibly is an anti-TC drug and AV reduces the %ATI probably due to its biological effects
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Effects of a Cordia salicifolia (porangaba) extract on the labeling of blood cells (BCs) with technetium-99m ((99m)Tc) and on the morphology of red BCs were evaluated. Labeling of cellular and molecular structures with (99m)Tc depends on a reducing agent. Some physical characteristics, as visible absorbance spectrum, electric conductivity, and refractive index of this porangaba extract, were also determined. Blood samples from Wistar rats were incubated with porangaba extract or with 0.9% NaCl (control). Labeling of blood constituents with (99m)Tc was performed. Plasma (P) and BCs, both soluble (SF-P and SF-BC) and insoluble (IF-P and IF-BC) fractions, were separated. The radioactivity in each fraction was counted, and the percentage of radioactivity incorporated (%ATI) was calculated. Blood smears were prepared, fixed, and stained, and the morphology of the red BCs was evaluated. Data showed an absorbance peak at 480 nm and electric conductibility and refractive index concentration-dependent. Porangaba extract decreased significantly (P < .05) the BC, IF-P, and IF-BC %ATI, and no modifications were verified on the shape of red BCs. Analysis of the results reveals that some physical parameters could be useful to aid in characterizing the extract studied. Moreover, it is possible that chemical compounds of this extract could have chelating/redox actions or be capable of binding to plasma and/or cellular proteins