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Search Results: 1 - 10 of 40629 matches for " Rafael Lopes Costa "
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Evaluation of Inherent Uncertainties of the Homogeneous Effective Thermal Conductivity Approach in Modeling of Printed Circuit Boards for Space Applications  [PDF]
Rafael Lopes Costa, Valeri Vlassov
Journal of Electronics Cooling and Thermal Control (JECTC) , 2013, DOI: 10.4236/jectc.2013.31005

Electronic components are normally assembled to printed circuit boards (PCBs). Such components generate heat in operation which must be conducted away efficiently from the small mounting areas to frames where the PCB is fixed. The temperature of the component depends on heat dissipation rate, technology and parameters of mounting, component placement and finally effective thermal conductivity (keff) of the board. The temperature of some components may reach significant magnitudes over 100°C while the PCB frame is kept at near-ambient temperature. The reliability of electronic components is directly related to operating temperature; so the thermal project should be able to provide a correct temperature prediction of all PCB components under the hottest operational condition. In space applications, the main way to spread and reject heat of electronic equipment is by thermal conduction once there is no air available to apply convection-based cooling techniques. The PCB keff is an important parameter for the electronics thermal analysis when the PCB is modeled as a simplified homogeneous board with a unique thermal conductivity. In this paper, an intrinsic uncertainty of such approach is firstly reveled and its magnitude is evaluated for a real space use PCB. The simulation uses SINDA/FLUINT Thermal Desktop and aims to determine the keff of the PCB by comparison between a detailed multi-layered anisotropic model and an

Indicadores de Sustentabilidade em Simula es de Negócios: uma proposi o no contexto do jogo de empresas SEE
Rafael Bonrim de Souza,Paulo da Costa Lopes
Contextus , 2010,
Abstract: O artigo foi desenvolvido com o objetivo de propor a inser o de indicadores de sustentabilidade em simula es de negócios. Para tanto, foi realizada uma pesquisa básica, qualitativa, descritiva, bibliográfica e documental. Foi elaborado um levantamento teórico-metodológico sobre jogos de empresas e sustentabilidade, foi introduzida a Global Reporting Initiative (GRI) como promotora de um padr o de comunica o global em a es empresariais sustentáveis, e apresentou-se o jogo de empresas SEE (Simulador de Estratégia Empresarial). Este artigo, entre outros propósitos, intenciona identificar, pela realidade dos relatórios sustentáveis brasileiros, estruturados segundo as diretrizes da GRI, e publicados em 2008, quais os indicadores – EC1, EN3, HR6, LA1, PR5 e SO1 – mais reportados por essas empresas. Esses s o os indicadores de sustentabilidade propostos para serem inseridos em uma ambiência de simula es de negócios amparada pelo jogo de empresas SEE.
Agronomic and Energetic Potential of Biomass Sorghum Genotypes  [PDF]
Fernanda Maria Rodrigues Castro, Adriano Teodoro Bruzi, José Airton Rodrigues Nunes, Rafael Augusto Costa Parrella, Gabrielle Maria Romeiro Lombardi, Carlos Juliano Brant Albuquerque, Maurício Lopes
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.611187
Abstract: The biomass sorghum [Sorghum bicolor (L.) Moench], is an interesting crop considering the necessity to invest in alternative sources to generate renewable energy. The objective of this experiment was to identify sorghum biomass genotypes with greatest agronomic and energetic potential, and verify if there is phenotypic association between agronomic and technological properties in the hybrids. The study was conducted in three cities of the Minas Gerais State, Brazil (Lavras, Uberlandia and Sete Lagoas). It was evaluated 16 genotypes of sorghum biomass, being 14 of them sensitive hybrids to photoperiod and two cultivars, as control, insensitive to photoperiod. The experimental design was a triple lattice 4 × 4, with plots formed by four linear rows of 5.0 m. The morphoagronomic characteristics evaluated for the three environments were: days to flowering (FLOW), plant height (PH), number of stems (NS) and green matter production (GMP). In the experiment conducted in Lavras, also it was evaluated the agronomic traits: stem diameter (SD) and dry matter production (DMP) besides the technological traits: higher heating value (HHV), crude fiber (CF), neutral detergent fiber (NDF) and acid detergent fiber (ADF). The genotype × environment interaction was significant for all traits. The hybrids had superior performance compared to the control genotypes. Biomass sorghum hybrids, sensitive to photoperiod, when compared with commercial hybrids of forage sorghum, insensitive to photoperiod, had an average production of 34 t ha-1 dry matter with 62% humidity and higher heating value of 4.400 Kcal/Kg. There was no phenotypic correlation between agronomic and technological characters evaluated.
Mean and Interannual Variability of Maize and Soybean in Brazil under Global Warming Conditions  [PDF]
Flávio Justino, Evandro Chaves Oliveira, Rafael de ávila Rodrigues, Paulo Henrique Lopes Gon?alves, Paulo Jorge Oliveira Ponte Souza, Frode Stordal, José Marengo, Thieres G. da Silva, Rafael Coll Delgado, Douglas da Silva Lindemann, Luiz Claudio Costa
American Journal of Climate Change (AJCC) , 2013, DOI: 10.4236/ajcc.2013.24024

Brazil is responsible for 27% of the world production of soybeans and 7% of maize. Mato Grosso and Para states in Brazil are among the largest producer. The viability to the cultivation of maize (Zea mays) and soybeans (Glycine max), for future climate scenarios (2070-2100, GHG) is evaluated based on crop modeling (DSSAT) forced by observational data and regional climate simulations (HadRM3). The results demonstrated that a substantial reduction in the yield in particular for maize may be expected for the end of the 21st century. Distinct results are found for soybeans. By applying the A2 climate changes scenario, soybean yield rises by up top 60% assuming optimum soil treatment and no water stress. However, by analyzing the inter-annual variability of crop yields for both maize and soybean, could be demonstrated larger year-to-year fluctuations under greenhouse warming conditions as compared to current conditions, leading to very low productivity by the end of the 21st century. Therefore, these Brazilian states do not appear to be economically suitable for a future cultivation of maize and soybeans. Improved adaptation measures and soil management may however partially alleviate the negative climate change effect.

Sociologia no ensino médio em um mundo em mudan?as: a quest?o da "confluência perversa"
Lopes, Doraci Alves;Camargo, Dulce Maria Pompêo de;Costa, Rafael Fernando da;
Cadernos CEDES , 2011, DOI: 10.1590/S0101-32622011000300007
Abstract: this article presents a reflection on the sociology pedagogical workshops offered monthly for the continuing formation of high school teachers of public schools, as well as for the formation of teachers certified in social sciences by the laboratory of teaching society and culture (lesc, puc-campinas 1998-2007). the concept of `perverse confluence' allowed us to rethink the workshops through the dispute between the democratic and neoliberal political projects, once school and education have, since the beginning of 1990, undergone transformation that have reached cademician relations, increasingly fragmented and deregulated. in addition, besides the implementation of large-scale assessments with a ranking among public schools, these started to be disputed by civil society's projects of non-formal education in `partnerships' little concerned with an internal emocratic discussion aiming to adapt to the concrete reality of schools. such challenges as far we can judge, are one of the manifestation focuses of `perverse confluence' in the country, hardly noticed during those lesc years and perhaps even today.
Alex Pinheiro Feitosa,Humbelina Silva Siqueira Lopes,Rafael Oliveira Batista,Monalisa Soares Costa
Engenharia Ambiental : Pesquisa e Tecnologia , 2011,
Abstract: This study aimed to evaluate the performance of graywater treatment system, aiming to use effluent in a rural environment. The tests were carried out in the field of University Federal Rural Semiarid (UFERSA) in Mossoró-RN. The gray water treatment system is comprised of grease trap, anaerobic tank, anaerobic filter, wetland and solar reactor. Physicochemical and microbiological analysis were made on effluents collected in points different system. The results showed that significant removals of turbidity, fecal coliform, biochemical oxygen demand, chemical oxygen demand, total solids, suspended solids, phosphorus and grease were obtained on system. The average solar radiation of 29.33 MJ m-2 d-1 and exposure time of 12 hours promoted removal up to 99.99 and 99.98% in the population of total coliform and fecal coliform. For agricultural use for agricultural use it is recommended that the treated effluent is applied with subsurface drip irrigation system, which minimizes environmental hazards and contamination of rural population.
Profile of Patients with Stroke and Disorders of the Vocal Tract  [PDF]
Lina Claudia Pereira Lopes, Daniel Almeida da Costa, Marcus Vinicius de Mello Pinto, Aline Ronis Sampaio, Lamara Laguardia Valente Rocha, Isabela Nardoni Bernardes, Rafael Batista Ferreira, Elias Sobreira Sathler, R. R. B. T. Vieira
World Journal of Neuroscience (WJNS) , 2017, DOI: 10.4236/wjns.2017.71008
Abstract: Background: The present work aims to characterize the profile of patients with stroke treat at a hospital located in the Region of the Mata of Minas Gerais, Brazil, considering the findings of the clinical vocal tract, kind of stroke, age and gender of such patients. Methodology: To obtain data, the clinical profile of 133 patients with a clinical or tomography diagnosis of stroke was analyzed, and the results were presented in percentage. For quantitative data average and analysis the tests were done with associations that held χ2 test, and for significance it was considered p < 0.05. Results: From the total of patients, 63 were women, accounting for 47.4% and the other 52.6% were males. Clinically, they were characterized with the highest percentage for ischemic stroke (89.4%) compared to the hemorrhagic type (10.6%). Most of them were referred for computed tomography (86.5%) and remained hospitalized for an average of 6.496 ± 7.372 days. Similar percentages were obtained in the analysis of the population in question, when considering if they had (54.1%) or not (49.6%) any damage in their speech, language skills or swallowing. There were different types of disabilities in patients with stroke. Men with an average age of 69.8 ± 13.9 presents mostly ischemic stroke, and the majority of patients with stroke had hemiplegia and abnormalities of the vocal tract, dysphasia, and aphasia. While older patients had an ischemic stroke and were presented with left hemiplegia, the younger ones suffered from hemorrhagic strokes that caused a disability characterized as right hemiplegic. Conclusion: Our results show important conclusions regarding the clinical evolution of the vocal tract of patients who suffered strokes during the period of the analysis, being useful for better comprehension of how the vocal tract from these patients evolved according to the kind of stroke, sex and age also allowing a contraposition with other future statistics periods available in literature. It can also be pointed out the difficulties in diagnosing the stroke and the concern with the immediate care, but not with its continuance or with its multidisciplinary approach, giving an evident life risk through dysphasia and the increase of permanent damage when there isn’t an appropriate work done with the patients.
Ecoepidemiologia da leishmaniose tegumentar no Município de Buriticupu, Amaz?nia do Maranh?o, Brasil, 1996 a 1998
Martins, Luzenice Macedo;Rebêlo, José Manuel Macário;Santos, Márcio Costa Fernandes Vaz dos;Costa, Jackson Maurício Lopes;Silva, Antonio Rafael da;Ferreira, Luiz Alves;
Cadernos de Saúde Pública , 2004, DOI: 10.1590/S0102-311X2004000300010
Abstract: this study presents the distribution of leishmaniasis in the town of buriticupu, maranh?o, brazil, by month, season, occupation, gender, and age from 1996 to 1998. these data were compared with those on sand flies obtained by other authors during the same period. the disease affected all age groups, in the following order: 0-5 years (4.1%), 6-10 (7.1%), 11-15 (13.6%), 16-21 (20.8%), 22-30 (21.1%), and > 30 (33.3%). the disease predominantly affected males (70.1%) and agricultural workers (52.5%), followed by students (17.7%), and domestic workers (16.0%). like the sand fly vector, the disease was distributed throughout the year, but the greatest concentration of cases was recorded in the dry season (58.5%), while sand flies presented bimodal peaks in the first two years and occurred more frequently in the rainy season in 1998. the disease continues to present the same characteristics as in the past, but there was a proportional increase in cases among children and females, suggesting transmission in the anthropic environment.
Regulatory T Cell Induction during Plasmodium chabaudi Infection Modifies the Clinical Course of Experimental Autoimmune Encephalomyelitis
Alessandro S. Farias,Rafael L. Talaisys,Yara C. Blanco,Stefanie C. P. Lopes,Ana Leda F. Longhini,Fernando Pradella,Leonilda M. B. Santos,Fabio T. M. Costa
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0017849
Abstract: Experimental autoimmune encephalomyelitis (EAE) is used as an animal model for human multiple sclerosis (MS), which is an inflammatory demyelinating autoimmune disease of the central nervous system characterized by activation of Th1 and/or Th17 cells. Human autoimmune diseases can be either exacerbated or suppressed by infectious agents. Recent studies have shown that regulatory T cells play a crucial role in the escape mechanism of Plasmodium spp. both in humans and in experimental models. These cells suppress the Th1 response against the parasite and prevent its elimination. Regulatory T cells have been largely associated with protection or amelioration in several autoimmune diseases, mainly by their capacity to suppress proinflammatory response.
Expans?o espacial da leishmaniose visceral americana em S?o Luis, Maranh?o, Brasil
Mendes, Wellington da Silva;Silva, Antonio Augusto Moura da;Trov?o, José de Ribamar;Silva, Ant?nio Rafael da;Costa, Jackson Maurício Lopes;
Revista da Sociedade Brasileira de Medicina Tropical , 2002, DOI: 10.1590/S0037-86822002000300005
Abstract: the space occupation and the expansion of american visceral leishmaniasis (avl) were described in the municipality of s?o luis, maranh?o, northeast brazil. avl medical notes from the funda??o nacional de saúde as well as official documents about the space occupation were analyzed from september 1982 to december 1996. avl cases were more likely to occur in recently settled suburbs and tended to follow the same spatial pattern observed for land occupations secondary to migratory fluxes.
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