Clonagem do pessegueiro 'Aurora-1' e de portaenxertos de umezeiro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos de modificações físicas sobre as propriedades de amido de tuberosas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação de atributos físico-químicos do solo sobre palhadas de diferentes poáceas e adubação nitrogenada em semeadura direta na cultura do feijoeiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da resistência à corrosão da liga Ti-30Ta submetida a diferentes taxas de deformação visando aplicações biomédicas

This study aims to evaluate the corrosion resistance of Ti-30Ta alloy when subjected to different strain rates. Samples of the alloy Ti-30Ta were obtained from the melting of pure elements in the arc furnace in inert atmosphere (argon gas). Then, the samples were subjected to a thermal treatment and to cold worked to obtain bars. After forging, the samples were machined in accordance with ASTME9-09 standard for carried out compression tests. To microstructural characterization, samples were sectioned longitudinal and transversally and embedded in resin. After, the wet sanding and polishing were performed, followed by a chemical attack, in order to study the microstructure under an optical microscope. Microhardness was measured on the samples that were subjected to microstructural characterization by using microhardness tester. Phases were evaluated by x-rays diffraction. Corrosion tests were carried out to evaluate the influence of deformation on the corrosion resistance. Results show that microstructure was not influenced by deformation

Projeto de adaptação do sistema de injeção do túnel transônico para ensaios em bocais de foguete

In this work, the project of a new experimental facility to be installed at the Aerodynamics Division of the Institute of Aeronautics and Space is presented. This new facility will provide means to perform experimental campaigns to analyze the flow behavior at different rocket nozzle concepts using cold gas that will be obtained from a modification of the Pilot Transonic Wind Tunnel air system. The new installation will enable less expensive experiments in a more secure environment, since the cold gas experimental procedures do not demand fuel storage and burn and security procedures are much less severe. Furthermore, experiments can be carried with different types of sensors, commonly used in wind tunnel tests. Also, the optical access is facilitated enabling the use of optical techniques for the characterization of flow properties inside the nozzles, such as pressure and temperature sensitive painting. The full project design and the operation conditions will be showed, as also some technical considerations about the flor behavior in the facility

Caracterização da liga Ti-30Ta após tratamento biomimético associado à incorporação de antibiótico

Surface treatments have been used to modify the surface of titanium alloys. The purpose of this study is to evaluate the surface of Ti-30Ta alloy after biomimetic approach associated to antibiotic incorporation. The ingots were obtained in arc melting furnace, treated and cold-worked by swaging. The surface treatment was performed in two steps: biomimetic treatment and antibiotic incorporation. For biomimetic treatment, first an alkaline treatment (NaOH 1M at 60ºC) was performed, followed by heat treatment and immersion in SBFx5 (Simulated Body Fluid) for a period of 24 hours. In order to incorporate the antibiotic, samples were immersed in a solution formed by drugs plus SBFx5 for 48 hours. The sample surfaces were analyzed by scanning electron microscopy (SEM), X-Ray diffraction (XRD), atomic force microscopy (AFM) and contact angle measurements. The release of antibiotic from coated implants was measured in phosphate buffer saline at pH 7.4 by using UV/VIS spectrometry. Results have shown changes on the surface after incorporating the drug, which is gradually co-precipitated with the Ca-P crystals, forming a uniform and rough layer on the metal surface

Caracterização da liga Ti-15Zr visando aplicações biomédicas

With advances in health care, has been na increase of demand for material that could replace the functions of the human body parts, thus evolved biomedic prosthesis which today are responsible for the constant improvement of the quality of life. The Titanium alloys are widely used as implants due to its properties, like high mechanical resistance, biocompatibility and corrosion resistance, and the addition alloying elements like Zirconium, may improve some of those properties. Such properties are related to the microstructure and consequently to the type of processing performed. The purpose of this dissertation was to characterize the experimental alloy Ti15Zr after route of processsing and heat treatment in order to extend the knowledge about this alloy. The latter has been abtained by fusion of pure metals in a arc melting furnace with an inert argon atmosphere. The material has been homogenized in a tube furnace at 950ºC for 24h and cold worked by swaging, after that, bars with 10 mm of diameter were obtained by the process of rotary forging. The samples were solubilized at 900º C for 2 hours and quenched in water. After that, 4 samples were submitted to the aging, at 400º C, 450º C, 500º C and 550º C. The microstructure and phase analysis was done by optical microscopy and X-rays diffraction (XRD), the mechanical characterization was carried out by microhardness test and finally, evaluation of corrosion resistance of the alloy by electrochemical tests. The XRD and the optical microscopy made it possible to analyze that the heat treatment influenced the phase shifting from α to α', and probably affected the alloy hardness, at the first aged sample at 500º Chas been a sudden increase in the value of hardness, probably by appearance of omega phase, unwanted phase to the medical application duo to great fragility, and finally ... (Complete abstract click electronic access below)

Comparação da dinâmica populacional e identificação dos estoques pesqueiros do camarão sete-barbas Xiphopenaeus kroyeri (Heller, 1862) (Decapoda, Penaeidae) no litoral brasileiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)