Reduced model for the thermo-fluid dynamic analysis of a power transformer radiator working in ONAF mode

This work introduces an extension of the semi-analytical reduced model presented in G. Ríos Rodriguez et.al., App Thermal Eng, 112:1271–1280 (2016); with the aim of analyzing the thermo-fluid dynamic behavior of a power transformer radiator working in ONAF (Oil Natural Air Forced) mode, considering vertical blowing of the fans. The objective of this research paper is the development of a numerical tool to be used during the design process of power transformers in order to obtain more detailed information about the radiators performance, either they are working in ONAF or ONAN (Oil Natural Air Natural) mode. Since it is observed both in the experimental measurements and in the numerical simulations that not all the radiator panels are blown by a single fan, the reduced model here presented considers a mixed situation wherein the heat is removed by natural convection in a fraction of the radiator while in the rest the heat is removed by forced convection. As a consequence, besides adding to the set of conservation equations introduced in G. Ríos Rodriguez et.al., App Thermal Eng, 112:1271– 1280 (2016); those corresponding to the momentum and energy balance for considering forced heat convection transfer, there appears the need of introducing additional equations for coupling the natural and forced heat convection transfer models. The reduced model developed in this work is applied to estimate different characteristic parameters of a power transformer radiator working in ONAF mode, like the oil flow rate, dissipated power, outlet and inlet oil temperatures, among others. The computed results are compared to those obtained by CFD simulations and experimental measurements carried out on an ad-hoc workbench for validation purposes. It is found that the reduced model reproduces with acceptable accuracy the values of the most important design variables at a very low computation cost. In this manner, it can be considered as a reliable and valuable tool in the design of power transformers, allowing to carry out parametric studies.Publicado en: Mecánica Computacional vol. XXXV, no. 4Facultad de Ingenierí

Reduced model for the thermo-fluid dynamic analysis of a power transformer radiator working in ONAF mode

This work introduces an extension of the semi-analytical reduced model presented in G. Ríos Rodriguez et.al., App Thermal Eng, 112:1271–1280 (2016); with the aim of analyzing the thermo-fluid dynamic behavior of a power transformer radiator working in ONAF (Oil Natural Air Forced) mode, considering vertical blowing of the fans. The objective of this research paper is the development of a numerical tool to be used during the design process of power transformers in order to obtain more detailed information about the radiators performance, either they are working in ONAF or ONAN (Oil Natural Air Natural) mode. Since it is observed both in the experimental measurements and in the numerical simulations that not all the radiator panels are blown by a single fan, the reduced model here presented considers a mixed situation wherein the heat is removed by natural convection in a fraction of the radiator while in the rest the heat is removed by forced convection. As a consequence, besides adding to the set of conservation equations introduced in G. Ríos Rodriguez et.al., App Thermal Eng, 112:1271– 1280 (2016); those corresponding to the momentum and energy balance for considering forced heat convection transfer, there appears the need of introducing additional equations for coupling the natural and forced heat convection transfer models. The reduced model developed in this work is applied to estimate different characteristic parameters of a power transformer radiator working in ONAF mode, like the oil flow rate, dissipated power, outlet and inlet oil temperatures, among others. The computed results are compared to those obtained by CFD simulations and experimental measurements carried out on an ad-hoc workbench for validation purposes. It is found that the reduced model reproduces with acceptable accuracy the values of the most important design variables at a very low computation cost. In this manner, it can be considered as a reliable and valuable tool in the design of power transformers, allowing to carry out parametric studies.Publicado en: Mecánica Computacional vol. XXXV, no. 4Facultad de Ingenierí

Effects of curing protocol and storage time on the micro-hardness of resin cements used to lute fiber-reinforced resin posts

Objectives: To determine the micro-hardness profile of two dual cure resin cements (RelyX - U100 (R), 3M-ESPE and Panavia F 2.0 (R), Kuraray) used for cementing fiber-reinforced resin posts (Fibrekor (R) - Jeneric Pentron) under three different curing protocols and two water storage times. Material and methods: Sixty 16mm long bovine incisor roots were endodontically treated and prepared for cementation of the Fibrekor posts. The cements were mixed as instructed, dispensed in the canal, the posts were seated and the curing performed as follows: a) no light activation; b) light-activation immediately after seating the post, and; c) light-activation delayed 5 minutes after seating the post. The teeth were stored in water and retrieved for analysis after 7 days and 3 months. The roots were longitudinally sectioned and the microhardness was determined at the cervical, middle and apical regions along the cement line. The data was analyzed by the three-way ANOVA test (curing mode, storage time and thirds) for each cement. The Tukey test was used for the post-hoc analysis. Results: Light-activation resulted in a significant increase in the microhardness. This was more evident for the cervical region and for the Panavia cement. Storage in water for 3 months caused a reduction of the micro-hardness for both cements. The U100 cement showed less variation in the micro-hardness regardless of the curing protocol and storage time. Conclusions: The micro-hardness of the cements was affected by the curing and storage variables and were material-dependent.FAPESP [07/02612-2]CNPq [307510/2010-7]CAPES (Brazil

A preoperative diagnostic test that distinguishes benign from malignant thyroid carcinoma based on gene expression

Accurate diagnosis of thyroid tumors is challenging. A particular problem is distinguishing between follicular thyroid carcinoma (FTC) and benign follicular thyroid adenoma (FTA), where histology of fine-needle aspirates is not conclusive. It is often necessary to remove healthy thyroid to rule out carcinoma. in order to find markers to improve diagnosis, we quantified gene transcript expression from FTC, FTA, and normal thyroid, revealing 73 differentially expressed transcripts (Pless than or equal to.0001). Using an independent set of 23 FTCs, FTAs, and matched normal thyroids, 17 genes with large expression differences were tested by real-time RT-PCR. Four genes (DDIT3, ARG2, ITM1, and C1orf24) differed between the two classes FTC and FTA, and a linear combination of expression levels distinguished FTC from FTA with an estimated predictive accuracy of 0.83. Furthermore, immunohistochemistry for DDIT3 and ARG2 showed consistent staining for carcinoma in an independent set 59 follicular tumors (estimated concordance, 0.76; 95% confidence interval, [0.59, 0.93]). A simple test based on a combination of these markers might improve preoperative diagnosis of thyroid nodules, allowing better treatment decisions and reducing long-term health costs.Universidade Federal de São Paulo, Mol Endocrinol Lab, Div Endocrinol, Dept Med, São Paulo, BrazilUniversidade Federal de São Paulo, Div Genet, Dept Morphol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilDuke Univ, Med Ctr, Dept Biostat & Bioinformat, Durham, NC USAJohns Hopkins Univ, Sch Med, Dept Neurosurg, Baltimore, MD 21205 USAUniversidade Federal de São Paulo, Mol Endocrinol Lab, Div Endocrinol, Dept Med, São Paulo, BrazilUniversidade Federal de São Paulo, Div Genet, Dept Morphol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilWeb of Scienc

Health promotion and education: a diagnosis of sanitation conditions using participatory research and community education (São João dos Queiróz, Quixadá, Ceará, Brazil)

This study was conducted in a rural community, São João dos Queiróz, a township in the county of Quixadá, Ceará, Brazil, using a combination of participatory research and community education in compliance with the health promotion reference and principles of the 1986 Ottawa Charter. The project was joined by representatives of several local government institutions and organizations from the grassroots community movement. The theme generating the research, as defined by an assembly meeting of the community association, was a diagnosis of sanitation conditions in the community. The starting point was the assessment of local conditions. Results showed adverse local conditions in sanitation, literacy, income, and employment. Suggestions for solving the problems were organized so as to be included in the planning agenda for local health policies. Evaluation was procedural and enriched with daily research activities. The problem-solving pedagogical approach developed during the educational process contributed to a critical reconstruction, appropriation, and sharing of the resulting knowledge.Este trabalho foi desenvolvido em uma comunidade rural ­ vila de São João dos Queiróz, Distrito do Município de Quixadá, Ceará, através da pesquisa participante articulada à educação popular, tendo como referencial a promoção à saúde de acordo com os princípios da Carta de Ottawa, 1986. Participaram do projeto representantes das diversas instituições públicas do distrito e entidades associativas ligadas ao movimento popular. O tema gerador, definido em assembléia da associação comunitária, foi o diagnóstico de saneamento, e o ponto de partida, o levantamento da condição situacional. Os resultados obtidos mostraram as precárias condições locais de saneamento, escolaridade, renda e trabalho. As sugestões para resoluções dos problemas foram organizadas para subsidiar a agenda de planejamento das políticas locais de saúde. A avaliação foi processual e enriquecida com práticas do cotidiano da pesquisa. A pedagogia problematizadora, desenvolvida durante o processo educativo, contribuiu para a construção e a reconstrução crítica dos conceitos de promoção à saúde e de saneamento, assim como para a efetivação da construção, apropriação e socialização dos conhecimentos produzidos

Galectin-3 immunohistochemistry for follicular patterned thyroid lesions

BV UNIFESP: Teses e dissertaçõe

Reduced model for the thermo-fluid dynamic analysis of a power transformer radiator working in ONAF mode

This work introduces an extension of the semi-analytical reduced model presented in Ríos Rodriguez et al. (2016), with the aim of analyzing the thermo-fluid dynamic behavior of a power transformer radiator working in ONAF (Oil Natural Air Forced) mode, considering vertical blowing of the fans. The objective of this research paper is the development of a numerical tool to be used during the design process of power transformers in order to obtain more detailed information about the radiators performance, either they are working in ONAF or ONAN (Oil Natural Air Natural) mode. Since it is observed both in the experimental measurements and in the numerical simulations that not all the radiator panels are blown by a single fan, the reduced model here presented considers a mixed situation wherein the heat is removed by natural convection in a fraction of the radiator while in the rest the heat is removed by forced convection. As a consequence, besides adding to the set of conservation equations introduced in Ríos Rodriguez et al. (2016) those corresponding to the momentum and energy balance for considering forced heat convection transfer, there appears the need of introducing additional equations for coupling the natural and forced heat convection transfer models. The reduced model developed in this work is applied to estimate different characteristic parameters of a power transformer radiator working in ONAF mode, like the oil flow rate, dissipated power, outlet and inlet oil temperatures, among others. The computed results are compared to those obtained by CFD simulations and experimental measurements carried out on an ad-hoc workbench for validation purposes. It is found that the reduced model reproduces with acceptable accuracy the values of the most important design variables at a very low computation cost. In this manner, it can be considered as a reliable and valuable tool in the design of power transformers, allowing to carry out parametric studies.Fil: Garelli, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Rios Rodriguez, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Storti, Mario Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Granata, Daniel. Tadeo Czerweny S. A.; ArgentinaFil: Amadei, Mauro. Tadeo Czerweny S. A.; ArgentinaFil: Rossetti, Marcelo. Tadeo Czerweny S. A.; Argentin

Numerical and experimental thermo-fluid dynamic analysis of a power transformer working in ONAN mode

This paper presents semi-analytical calculations, computational fluid dynamic simulations and experimental measurements accomplished on a typical 30 MVA power transformer. An ad hoc workbench was devised to carry out the experimental measurements. This facility allowed to estimate the values of different key variables involved in heat dissipation within the radiator, like convective heat transfer coefficients, oil-flow rate, air-flow speed between radiator fins and overall dissipated heat, among others. The main objectives of the study are to analyze the cooling capacity of the current radiator design working in ONAN mode and to validate the numerical simulation and calculation procedures for further design optimizations. The coupled thermo-hydraulic numerical simulations were performed on a computer cluster due to the high computational cost of the resulting models. The results of the simulations show good agreement with the experimentally measured values and with those obtained with the semi-analytical model, thus confirming that this model together with the CFD simulations are an accurate analysis tool. The heat transfer coefficients in the oil, the radiator panel and the air are computed. It is found that convective heat transfer from the panel to the air is approximately 10 times lower than heat transfer in the oil. Possible improvements on the current radiator design are briefly mentioned.Fil: Rios Rodriguez, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Garelli, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Storti, Mario Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Granata, Daniel. Tadeo Czerweny S.a.; ArgentinaFil: Amadei, Mauro. Tadeo Czerweny S.a.; ArgentinaFil: Rossetti, Marcelo. Tadeo Czerweny S.a.; Argentin