Habitabilidade em exoplanetas do tipo terrestre

A astrobiologia, ciência que estuda a origem, evolução, distribuição e futuro da vida, tem como escopo a procura por vida em outros ambientes, como por exemplo, exoplanetas, planetas estes localizados fora do sistema solar. Através de observações e modelos teóricos que estimam alguns parâmetros gerais (composição, tipos de compostos presentes) pode-se criar um ambiente possível para o exoplaneta. O ambiente em que o planeta está inserido é um fator que pode ser determinante em relação a sua habitabilidade. A Zona Habitável é um dos parâmetros passíveis de delimitar os planetas que poderiam ser habitáveis. Muitos planetas identificados até agora têm características similares à da Terra. Entretanto, a maioria dos planetas, com possibilidade de ser do tipo terrestre, identificados até hoje são considerados Super Terras Quentes (STQ), pois estão fora da zona habitável uma vez que estão muito próximos de suas estrelas (período orbital da ordem de dias ou menos). Alguns desses estariam presentes na Zona habitável de suas respectivas estrelas, como é o caso de Gl 581 g, um planeta do sistema multi-planetário da estrela Gl 581. A proximidade da estrela sugere que eles apresentam uma rotação afetada por forças de maré. Deste modo, a taxa rotacional do planeta é sincronizada, sendo que uma de suas faces não recebe a energia da estrela, tornando-se gelada e a outra face recebe constantemente a energia da estrela, tornando-se muito quente. Embora em geral descarta-se a habitabilidade em STQ, estudos de resistência de vida em ambientes extremos não são muito explorados. As características analisadas partirão da premissa que o tipo de vida procurada será semelhante ao tipo de vida que encontramos na Terra, isto é, utilizando a água como solvente e apresentando uma química baseada no elemento carbono (Kaltenegger, L. et al., 2008)... (Resumo completo, clicar acesso eletrônico abaixo)

Análise preliminar para a estimativa da perda de calor sensível de um fluido homogêneo térmico em um reservatório de geometria cilindrica

This work analyzed the loss of sensible heat from one fluid to be considered homogeneous heat distribution on a thermal reservoir with cylindrical geometries composite insulating layers. We studied two thermal reservoirs with a volume of 20 liters, and the first has a layer thickness of 75 mm of expanding polyurethane foam wrapped in the polycarbonate container and the second container has only layer thickness of 5 mm of polycarbonate, as insulation of fluid of the external environment. The experimental results are compared with theoretical results obtained through a calculation script, displayed and detailed during the work development, from the theory of energy balance. The maximum error introduced between the theoretical and experimental results were 3.5% and 1.4% respectively for the Boilers with or without a polyurethane coating

Avaliação do tempo e da concentração do condicionamento com ácido fluorídrico sobre a resistência de união entre cerâmica e cimento resinoso

The aim of this study was to verify through microtensile test the influence of time and concentration of surface conditioning with hydrofluoric acid and its interference in the adhesion of dual resin cement to porcelain.We used 32 bodies of glass-ceramic lithium disilicate system IPS e.max Press LT with dimensions of 6mm thick, 8 mm in length and 8 mm in length, which will be molded to obtain composite resin blocks corresponding to blocks ceramics. Ceramic and resin blocks were divided into 16 groups (n = 4) and numbered according to the concentration of hydrofluoric acid (2.5%, 5%, 7.5% and 10%) and conditioning time (20 seconds, 40 seconds, 1 minute and 2 minutes). The blocks were cleaned in ultrasonic apparatus with distilled water and dried with compressed air, subjected to acid etching and air-jet washed with water, dried with compressed air and received application of silane agent Monobond-S, followed by adhesive Excite ( Ivoclar Vivaden). Each ceramic block was bonded to the corresponding block of resin through the resin cement Multilink Automix. The specimens were cut to obtain nine micro samples for each set of ceramic-resin with 1 mm X 1 mm X 12 mm in length, which were submitted to microtensile test. The results were analyzed with descriptive statistics and analysis of variance with significance level of 5%, revealing that there were statistically significant (p = 0.000001 <0.05). From the Tukey test can be concluded that etching with hydrofluoric acid and 2.5% for 120 seconds gave the best bond strength, however, no statistical difference between the conditioning with the same acid in the concentration of 5.0% for 20 to 40 seconds

Modelagem e avaliação de um sistema de refrigeração por absorção para residências e instalações de pequeno porte

This work presents a study of the absorption refrigeration system and the modeling and evaluation of two cycles using the binary solutions water-lithium bromide and ammonia-water for an equipment to be used in small size plants like residences. The study and evaluation aims the complete understanding of all parts of the system and the influence of each one of them as well as the spread of the knowledge to raise the use of this type of equipment in all sizes in order to decrease the energetic consumption of plants of all scales and making viable the alternative sources. The study is done in each element of the cycle separately and in some auxiliary equipments required in the operation such as the main power source, the solar collector. The software used for modeling, with emphasis on thermal part, was the EES (Engineering Equation Solver), that permitted the thermal balance calculus and acquisition of the used fluids properties. The results obtained for the equipment shows the system is more complex than the widely used in business, however, it can be viable and represents an alternative to increase the energetic efficiency

Síndrome dilatação-vólvulo gástrico em cães

The gastric dilatation- volvulus (GDV) is an acute and potentially lethal disease, characterized by increased size of the stomach associated with mesenteric rotation on its axis, which affects mainly large breed dogs and giants with deep and narrow chest. The diagnosis is made from the history, physical examination, clinical signs and radiographic evaluation. It is an emergency that requires immediate therapy and consists on protocols to treat shock, gastric decompression, surgical repositioning of the stomach, gastropexy and intensive post-operative care. Despite the significant progress in the elucidation of pathophysiological events, risk factors and treatment, there was almost no progress in determining the root causes of this disease. A significant advance was recently described in the literature on this topic is the technique of gastropexy laparoscopy. Instruct the owners of the high risk breeds is extremely important to avoid situations in which the severity of the illness make the surgical treatment impracticable and the animal’s condition irreversible

Osteossarcoma apendicular: revisão de literatura

Osteosarcoma is the most common primary bone cancer in dogs. It affects most commonly dogs of big or giant breeds with 7 to 8 years and the etiology is unknown. Osteosarcoma is defined as a bone matrix-producing malignant mesenchymal tumor and has a predilection for the metaphyseal region of appendicular skeleton, however, it can affect axial skeleton and soft tissues. Distal radius is the most commonly affected site. The definitive diagnosis of osteosarcoma can be obtained with history, physical examination, radiographs and biopsy. Lung is the most common organ for metastatic disease. The mainly treatment for osteosarcoma is limb amputation and systemic chemotherapy for metastatic disease control. Limb-sparing surgery is a viable alternative to amputation for dogs with concomitant conditions that impede limb amputation. Palliative treatments for osteosarcoma have been studied such as local and systemic radiotherapy, immunotherapy and biphosphonates. This study has the objective of presenting the aspects of diagnosis and treatment for appendicular osteosarcoma

Grãos em carbonatos marinhos cretácicos da Bacia Potiguar: formações Ponta do Mel e Jandaíra

This work aims to identify and photograph grains that compose important Cretaceous carbonate units of the Potiguar Basin, represented by the Ponta do Mel and Jandaíra formations (Albian-Campanian). Petrographic investigation of thin sections was essential. The samples studied come from wells and surface samples from the collection UNESPetro – UNESP, Rio Claro. In the Ponta do Mel Formation, the grains consist of ooids, oncoids, peloids and bioclasts. Regarding to the identified bioclasts, the solenoporacean red algae, mollusks (bivalves and gastropods), echinoids, foraminifera, ostracods and worms were the dominant elements. In the Jandaíra Formation, the grains are composed by ooids, peloids and bioclasts, which are represented by green algae, mollusks (bivalves and gastropods), benthic foraminifera miliolids, worms, echinoderms and ostracods. The grains found in the Ponta do Mel Formation are somewhat similar to those found in the Jandaíra Formation, with the exception of calcareous algae. The subsurface material from the Ponta do Mel Formation is derived from the upper part of the unit, representing marine high-energy carbonates, which also contains ooids and Trocholina. The samples of Jandaíra Formation, collected in outcrops, often contain green algae, mollusks and miliolids, and come from inner shelf and lagoon facies previously described

Análise teórica e experimental de uma ventaneira de alto forno, visando seu comportamento térmico e fluidodinâmico

In this work, it was studied the thermal and fluid dynamic behavior from theorical and experimental point of view of a blast furnace tuyere. The tuyere is responsible for the hot air insuflation into the blast furnace. The parameter used in the comparison was the difference between the cooling water inlet and outlet temperatures. There were used forced convection correlations inside circular sections with adequations for non circular sections. Based on operations dates of flux and thermal loads it was possible to model numerically the tuyere, and, since it was obtained the wall temperatures, estimate the conduction and convection resistances and the heat flux through the walls in contact with the water. The total heat fluxes from wall to water were applied to the energy conservation equation where could be estimated the theorical temperature variation. Compared to the real value, the theorical value presented a difference of 0,2 °C. Considering that the boundary conditions around the tuyere are transitories and that your channels have some rugosity irregularities we can consider the estimation method for cooling system coherent with the real operational parameters

Análise teórica e simulação computacional de um sistema de resfriamento líquido de processadores de computadores pessoais

This paper aims to study the thermal aspects involved in a liquid cooling system for processors, analyzing their competitiveness and efficiency across the fins and fan system usually used by personal computers, because electronic components become more potent and consequently current methods of cooling are becoming ineffective. The liquid cooling system and air cooling system have different heat transfer mechanisms that involve mainly convection and conduction heat transfer modes, and, furthermore, requires an analysis of fluid dynamics, which can evaluate the losses involved in the closed system, consisting in an exchanger heat pipe and water blocks in liquid cooling system or heat sink and turbo-axial fan in the air cooling system

Cálculo do tempo de permanência de um cilindro de laminação em um equipamento de aquecimento por indução durante um processo de têmpera

Induction heating is a process closely linked to the concepts of heat transfer. It also covers electromagnetic induction and effect of film. Many companies use this technology in their processes due to the high accuracy that can be obtained at temperatures induced. However the dominance of this technology is not common among Brazilian industries. This involves complex systems of equation and heat exchange in transient conduction, and convection and radiation losses. With this work we seek the ability to analyze which parameters influence over this process and the order of magnitude of time required for heating a cylindrical part

Aspectos clínicos e cirúrgicos do osteossarcoma canino

Osteosarcoma is the primary osseous neoplasia frequently diagnosed in dogs and it’s the main answerable for more than 85% of the neoplasias origened from the skeleton. The average age of onset of the lesion is 7 years, especially in large breeds and giant, with males being more affected than females. In general, 75% of osteosarcomas develop in the appendicular skeleton and 25% in the axial. The forelimbs are more affected than the hindlimbs, since support 60% of body weight. The osteosarcoma diagnosis is made by the analys of the animal’s clinic historic, detailed physique exams, blood exams alkaline phosphatase, xray exams, cytology, biopsy. The treatment of choice is the amputation associated to the chemotherapy. However, in some cases the member is preserved by the allograft technic. The chemotherapy associated to the surgery reduces the total load of the tumor, lengthens the interval of the life and improves the quality of pacient’s life. The most used medicines are cisplatin and doxorubicin. They can be used in separated or associated ways. The prognostic of dogs with osteosarcoma is reserved

Imunidade de aves (Gallus gallus) para Salmonella enterica subesp. enterica Sorovar Gallinarum biovar Gallinarum

Pós-graduação em Medicina Veterinária - FCAV

Comportamento e organização dos cromossomos holocêntricos de heterópteros da região Sul do Brasil baseados em sequências repetitivas DNA, meiose e análise ultraestrutural

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação eletroanalítica e cromatográfica do corante solvente azul 14 em amostras de combustíveis

Métodos comparativos foram desenvolvidos para detectar e quantificar o corante solvente azul 14 (SA-14) em amostras de combustíveis. O método eletroanalítico foi baseado na técnica de voltametria de onda quadrada (VOQ) com detecção em +0,60 V vs. Ag/AgCl sobre o eletrodo de carbono vítreo, usando tampão Britton-Robinson e N, N-dimetilformamida (1:1, v/v) como eletrólito suporte. Para metodologia, envolvendo a cromatografia líquida de alta performance (CLAE) foi empregada uma fase móvel composta de acetonitrila e cloreto de lítio (85:15, v/v) e a detecção eletroquímica foi realizada em um potencial de oxidação em +0,65 V vs. Ag/AgCl. Sob as melhores condições de trabalho curvas de calibração foram obtidas, para ambos os métodos, as quais foram lineares na faixa de concentração de 5,0×10 -7 a 6,0×10 -6 mol L-1 (VOQ) e 8,0×10 -8 a 3,0×10 -6 mol L-1 (CLAE). Os métodos foram aplicados para quantificar o corante em amostras de álcool e querosene após um simples processo de extração em fase sólida com resultados de recuperação satisfatórios.

Efeito da limpeza pós-condicionamento e do tratamento térmico do silano na resistência de união de um cimento resinoso à cerâmica

Pós-graduação em Odontologia - FOA