RESUMO Durante um incêndio, a alvenaria pode se degradar devido a ação das altas temperaturas. O revestimento de argamassa, sendo o último componente da alvenaria, pode sofrer uma redução considerável em suas propriedades mecânicas. O estudo de alterações macroestruturais, como a resistência de aderência à tração em argamassas de revestimento diante da exposição da alvenaria a altas temperaturas, é importante para compreender o nível de degradação das paredes de alvenaria para que se possa aperfeiçoar as recomendações de projeto e garantir a segurança dos usuários durante uma situação de incêndio. Neste sentido, esta investigação busca analisar a resistência de aderência à tração do revestimento de argamassa em paredes de alvenaria, em condições de temperatura ambiente e em altas temperaturas. O programa experimental consistiu em confeccionar uma parede de alvenaria em escala real e submetê-la à curva padrão ISO 834 durante 240 minutos. Antes do programa térmico iniciar, foram realizados os ensaios de resistência à tração do revestimento de argamassa nas extremidades da parede, região que não é afetada pela ação térmica. Após o ensaio de resistência ao fogo foi verificada a resistência de aderência à tração na superfície não exposta e os resultados foram submetidos a uma análise estatística. Apesar da alvenaria ter mantido sua estabilidade e estanqueidade durante os 240 minutos do ensaio de resistência ao fogo, foi classificada como EI-180, visto que a capacidade de isolamento térmico se manteve por 193 minutos. Observou-se uma redução de 71,4% na resistência de aderência do revestimento de argamassa com o substrato após a exposição da parede às altas temperaturas, indicando uma variância estatisticamente significativa.

ABSTRACT During a fire, the masonry can degrade due to the action of high temperatures. Mortar coating, being the last component of masonry, can suffer a considerable reduction in its mechanical properties. The study of macro-structural changes, such as the tensile bond strength in coating mortars when masonry is exposed to high temperatures is important to understand the level of degradation of masonry walls to allow the improvement of the design recommendations and ensure the user safety during a fire situation. In this sense, this investigation seeks to analyze the tensile bond strength of the mortar coating on masonry walls at ambient temperature and high temperature. For the experimental study, a full-scale masonry wall was built and submitted to the ISO 834 standard curve for 240 minutes. Before the thermal program starts, the tensile bond strength tests of the mortar coating were carried out at the ends of the wall which is a region that is not affected by the thermal action. After the fire resistance test, the tensile bond strength on the unexposed surface was verified and the results were subjected to statistical analysis. Although the wall maintained its stability and integrity during the 240 minutes of the fire resistance test, it was classified as EI-180, since the thermal insulation capacity was maintained for 190 minutes. A reduction of 71.4% in the tensile bond strength of the mortar coating with the substrate was observed after the exposure of the wall to high temperatures, indicating that the variance is statistically significant.

Resumen Objetivo. El objetivo de este estudio fue proporcionar evidencia molecular de infección por C. burnetii en ovinos y caprinos de algunos rebaños de Valledupar, Cesar, Colombia. Materiales y métodos. Quince rebaños de ovinos y caprinos fueron seleccionados a conveniencia para investigar la infección por C. burnetii, durante marzo y abril de 2013. En este estudio se incluyeron 328 caprinos y 66 ovinos de 15 rebaños. La leche procedente de ovinos y muestras de moco vaginal de caprinos fueron analizados mediante PCR (Reacción en Cadena de Polimerasa) para la detección de ADN del gen transposasa (IS1111) de C. burnetii. Resultados. Se encontró ADN de C. burnetii en 6% (4/66) de leche de oveja y 0,6% (2/328) de moco vaginal de cabras. El 13% (2/15) de los rebaños tenían al menos un animal infectado. Discusión. Nuestros hallazgos sugieren la circulación de C. burnetii en ovinos y caprinos de algunos rebaños de Valledupar, Colombia, y destaca la posibilidad de ocurrencia de infecciones en humanos y animales. Conclusiones. La detección de C. burnetii en la leche de oveja podría representar un factor de riesgo para la salud pública de las personas que consumen con frecuencia leche cruda, quesos o personas que trabajan en la agricultura y manipulación de ganado. Otros estudios son necesarios para evaluar otras rutas como la mordedura de la garrapata, las heces, la leche de las cabras y el moco vaginal de las ovejas de esta región de Colombia.

Abstract Objective. The aim of this study was to provide molecular evidence of C. burnetii in sheep and goats from some herds of Valledupar, Cesar, Colombia. Materials and methods. Fifteen herds of sheep and goats were chosen by convenience to investigate the infection by C. burnetii, during March and April of 2013. 328 female goats and 66 sheep from 15 herds were included in this study. Milk from ewes and vaginal mucus samples from goats were analyzed by Polymerase Chain Reaction for DNA detection of transposase gene (IS1111) of C. burnetii. Results. DNA of C. burnetii in 6% (4/66) of sheep’s milk and 0.6% (2/328) vaginal mucus from goats was found. 13% (2/15) of the herds had at least one infected animal. Discussion. Our findings suggest the circulation of C. burnetii in sheep and goats from some herds of Valledupar, Colombia, and it highlights the possibility of occurrence of infections in humans and animals. Conclusions. The detection of C. burnetii in sheep milk could represent a public health risk factor for people who consuming raw milk, cheeses or people associated to agriculture and livestock handling. Further studies are necessary to evaluate other routes such as tick’s bite, feces, milk from goats and vaginal mucus from sheep of this region of Colombia.

Abstract The analysis of cracked brittle mechanical components considering linear elastic fracture mechanics is usually reduced to the evaluation of stress intensity factors (SIFs). The SIF calculation can be carried out experimentally, theoretically or numerically. Each methodology has its own advantages but the use of numerical methods has become very popular. Several schemes for numerical SIF calculations have been developed, the J-integral method being one of the most widely used because of its energy-like formulation. Additionally, some variations of the J-integral method, such as displacement-based methods, are also becoming popular due to their simplicity. In this work, a simple displacement-based scheme is proposed to calculate SIFs, and its performance is compared with contour integrals. These schemes are all implemented with the Boundary Element Method (BEM) in order to exploit its advantages in crack growth modelling. Some simple examples are solved with the BEM and the calculated SIF values are compared against available solutions, showing good agreement between the different schemes.

We prospectively sampled flavivirus-naïve horses in northern Colombia to detect West Nile virus (WNV) and St. Louis encephalitis virus (SLEV) seroconversion events, which would indicate the current circulation of these viruses. Overall, 331 (34.1%) of the 971 horses screened were positive for past infection with flaviviruses upon initial sampling in July 2006. During the 12-month study from July 2006-June 2007, 33 WNV seroconversions and 14 SLEV seroconversions were detected, most of which occurred in the department of Bolivar. The seroconversion rates of horses in Bolivar for the period of March-June 2007 reached 12.4% for WNV and 6.7% for SLEV. These results comprise the first serologic evidence of SLEV circulation in Colombia. None of the horses sampled developed symptoms of encephalitis within three years of initial sampling. Using seroconversions in sentinel horses, we demonstrated an active circulation of WNV and SLEV in northern Colombia, particularly in the department of Bolivar. The absence of WNV-attributed equine or human disease in Colombia and elsewhere in the Caribbean Basin remains a topic of debate and speculation.

En el presente trabajo se calculan los indices de esfuerzos y los factores de flexibilidad para momentos aplicados dentro y fuera del plano en codos de tuberia utilizando el metodo de elementos de contorno (MEC). Este metodo ha demostrado buen desempeno en el estudio elastico de solidos semi-infinitos, solidos de pared gruesa e inclusive en placas de pared delgada. El objetivo de este trabajo es determinar el rango de aplicabilidad del mismo a cascarones cilindricos y geometrias no lineales, tal es el caso de codos de tuberia, elementos de particular interes industrial. Para llevar a cabo este estudio se utilizaron nueve modelos de codos de tuberia de geometria comercial, todos los modelos fueron mallados utilizando una cantidad y distribucion identica de nodos y elementos, el numero de elementos fue escogido de tal forma que se obtuvieran buenos resultados en tiempos de calculo competitivos con respecto a otros metodos. Los resultados obtenidos fueron comparados con las expresiones encontradas en las normas ASME y contra los factores sometidos al factor de correccion propuesto por Thomas (1981). Se encontro que el metodo muestra buenos resultados dentro de un rango de esbeltez (relacion diametro espesor) entre 10 y 23, por encima del cual los modelos presentan un colapso de la seccion transversal del extremo cargado.

Stress indexes and bend flexibility factors, for in-plane and out-plane bending moments applied to piping elbows, were calculated using the Boundary Element Method (BEM). This method has proved to be very effective in the elastic study of semi-infinite solids, thick wall solids and even thin walled shells. The objective of this work is to determine the range of applicability of the BEM to the analysis of cylindrical thin walled shells and non-linear geometries, in this case piping elbows, objects of particular industrial interest. For this study, nine models of elbows with commercial geometries were used, all were meshed using an identical quantity and distribution of nodes and elements. The total number of elements was chosen in a way that the time consumed were competitive in comparison with other methods. The results of the simulations were compared with the analytical expressions found in the codes, and with the expressions corrected by the factors proposed by Thomas (1981). These results indicates that the BEM its applicable in a range of the diameter thickness ratio between 10 and 23.

Neste artigo, discutem-se o papel da informação digital e sua importância tanto para as universidades tradicionais quanto para as que adotam o paradigma de ensino a distância. Além disso, descreve-se a infra-estrutura básica necessária para a produção e disponibilização de acervo digital, destacando-se a criação de um Núcleo de Construção e Manutenção de Acervo Digital e de um Núcleo de Criação de Material Didático. Analisam-se também as diferenças relacionadas à disponibilização e pagamento de direitos autorais de documentos digitais disponibilizados em ambientes públicos ou restritos. Finalmente, apresentam-se as experiências dos autores no gerenciamento da informação digital disponibilizada aos alunos do ensino presencial.

This paper discusses the role of digital information and its importance for both the traditional universities and the ones which follow the paradigm of distance education. It also describes the basic infrastructure needed for production and availability of the digital holdings, pointing out the establishment of a Nucleus of Construction and Maintenance of the Digital Holdings as well as a Nucleus of Generation of Didactic Material. It also analyzes the differences related to the availability and payment of copyright of digital documents available in public and private environments. Finally, some authors experiences are presented as regards management of digital information available for classroom students.

Os imóveis possuem grande durabilidade, e no decurso de sua vida útil, sofrem diminuições de qualidade, devidas ao uso e à desatualização funcional. Estas perdas levam à progressiva redução do valor que o imóvel atinge no mercado. O formato desta curva de desvalorização não é conhecido, à principio. Este artigo apresenta as técnicas de estimação da depreciação para um conjunto de dados. Os modelos foram encontrados por regressão múltipla, comparando-se os resultados com os obtidos empregando os coeficientes padronizados (arbitrários), na forma tradicional.

The real estate goods has great durability, and its quality progressively reduces about the economic life, by functional and use. This losses goes to diminishing market value. The functional form of this curve isn t know. This paper presents the estimation techniques to depreciation, with regression analysis, comparing with the traditional (and arbitrary) coefficients.

Este artigo descrevo uma pesquisa cujo objetivo é a busca de modelos estatísticos de múltiplas variáveis, que expliquem a formação de valor de aluguel de apartamentos residenciais em Porto Alegre. A amostra é composta por apartamentos ofertados em junho de 1992, tendo como universo todos os imóveis oferecidos no período. Do total de 1819 unidades, foram selecionados 504 imóveis, nos quais foram investigadas diversas características, tais como estado do prédio e condições do entorno, complementadas por informações de órgãos públicos. Os dados obtidos foram testados através de análise fatorial e de regressão, com a compilação de modelos econométricos (hedônicos), em vários níveis de agregação. A análise demonstrou que o mercado pode ser explicado através de modelos deste tipo, que apresentam diferenças significativas, conforme o subconjunto de dados, mas permitem a obtenção de modelos para todos os imóveis e um melhor entendimento do funcionamento do mercado imobiliário

This research work aim at investigating the behavior of the real estate market of the city of Porto Alegre, through the use of multiple variable statistical models, which explain the value formation of housing rents. The models developed were based on a sample of 504 apartments, from several different areas of the city, offered in the market during July 1992. The universe is all properties offered in that period. The models developed were based on a sample of 504 apartments, extracted of the total of 1819. In that apartments, a number of variables had their influence in the value of rent investigated, like building condition and proximity conditions, completed by information of public institutions. The data were tested by factor and regression analysis, with the compilation of econometric models (hedonic). in various aggregation levels. The analysis demonstrated what the market can to be explicated by this models, what present significative differences, according to data collection, but permit the obtainment of models for all dwellings and a best understanding of working of real estate market