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da Silva M.B.,URI Integrated Regional University Brazil
Revista brasileira de enfermagem | Year: 2011

Descriptive research, with qualitative approach, that aimed to identify occupational hazards and weaknesses self-reported by motorcycle drivers. Data were collected in the first half of 2010 through interviews with twelve motorcycle drivers, invited to participate and work on two central points of a municipality in the state of Rio Grande do Sul, Brazil. Data were analyzed using thematic analysis, from which emerged five categories. According to subjects' perception, accidents and assaults represent the greatest risks of the profession. It can be inferred that the actions of health education and disease prevention should be governmental and no governmental strategies that would assign value to the health and safety of these workers. Source

Qualitative study that aimed at investigating concepts and practices of nursing technicians on biosecurity and its interface with biological hazards, with 20 workers developed a clinical care unit of a hospital in the interior of Rio Grande do Sul. Data were collected through interviews and systematic observation. Thematic analysis was the methodology used for data processing. The negligence of its employees on the use of individual protection equipment and work overload are risk factors for accidents with biological material. Suggested that partnerships between the actors involved in caring for the construction of healthy environments and accountability for negligence on biosecurity. Source

Centeno F.R.,Federal University of Rio Grande do Sul | Da Silva C.V.,URI Integrated Regional University Brazil | Franca F.H.R.,Federal University of Rio Grande do Sul
Energy Conversion and Management | Year: 2014

This paper presents a study of the effect of thermal radiation in the simulation of a turbulent, non-premixed methane-air flame. In such a problem, two aspects need to be considered for a precise evaluation of the thermal radiation: the turbulence-radiation interactions (TRI), and the local variation of the radiative properties of the participating species, which are treated here with the weighted-sum-of-gray-gases (WSGG) model based on newly obtained correlations from HITEMP2010 database. The chemical reactions rates were considered as the minimum values between the Arrhenius and Eddy Break-Up rates. A two-step global reaction mechanism was used, while the turbulence modeling was considered via standard k-É model. The source terms of the energy equation consisted of the heat generated in the chemical reaction rates as well as in the radiation exchanges. The discrete ordinates method (DOM) was employed to solve the radiative transfer equation (RTE), including the TRI. Comparisons of simulations with/without radiation (which in turn was solved with/without TRI) demonstrated that the temperature, the radiative heat source, and the wall heat flux were importantly affected by thermal radiation, while the influence on species concentrations proved to be negligible. Inclusion of thermal radiation led to results that were closer to experimental data available in the literature for the same test case considered in this paper. Inclusion of TRI improved the agreement, although in a smaller degree. The main influence of TRI was mainly on global results, such as the peak temperature and the radiant fraction. The results show the importance of thermal radiation for an accurate prediction of the thermal behavior of a combustion chamber. © 2013 Elsevier Ltd. All rights reserved. Source

Dos Santos A.V.,URI Integrated Regional University Brazil
Solid State Communications | Year: 2011

The importance of using theoretical methods for first principles calculations to have a better understanding of new material properties gives a detailed study on the properties of the ground state. In the present paper a study was carried out on the effects of a carbon atom inserted into the Ni 3Al structure changing its crystalline FCC to a perovskite structure in the form of Ni3AlC. Initially, we show the equilibrium volume of the two composites where there is a good agreement with the experimental value. In addition, we point out a magnetic structure where we find low magnetization in the composite Ni3AlC and reveal an appreciable magnetization in the composite Ni3Al. In order to obtain the results above we used the first-principles method: the Linearized Augmented Plane Wave (LAPW) method within the Generalized Gradient Approximation (GGA). Besides, we carried out a comparison with the experimental results presented in the literature, which showed reasonable agreement between theory and experiment. © 2010 Elsevier Ltd. All rights reserved. Source

Santos A.V.D.,URI Integrated Regional University Brazil
Computational Materials Science | Year: 2012

The theoretical prediction of compounds' properties is a desired dream by physicists, chemists and materials engineers; here we will establish a model to predict the stability of alloys, using first-principles LAPW calculations (Linearized Augmented Plane Waves) which is a APW modification (Augmented Plane Waves Method of Slater). We propose to calculate the energy of formation and cohesive energy of iridium-iron alloys and iridium-iron nitrides. In this discussion we will find a methodology that can be applied to solids with different atoms, creating a model to calculate the stability of these alloys. In our calculations we found a unit cell volume with a high increase when we changed from alloys to nitrides, thereby strongly influencing the energy of formation and cohesive energy. We also study the pressure in response to changes in the volume and the total energy of the compound, verifying that the same volume of balance was found in the minimum of cohesive energy of compounds at zero pressure. Finally, we discuss the critical pressure between ferromagnetic and non-magnetic phases, which proves to be of the same order of magnitude of some experimental and theoretical results of other systems. © 2012 Elsevier B.V. All rights reserved. Source

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