Avaliação do comportamento mecânico sob deformação da liga Ti- 30Ta visando aplicações biomédicas

Titanium and its alloys have been used for biomedical applications due their excellent properties such as high corrosion resistance, biocompatibility and mechanical properites. In this study, microstructural and mechanical properties of Ti-30Ta alloy was evaluated during its processing. Ti-30Ta alloy ingots were produced from sheets of commercially pure titanium (99.9%) and tantalum (99.9%). Its melting was realized in arc melting furnace in an argon atmosphere. After homogenizing at 1200ºC, ingots were cold worked by swaging. Samples with 13 mm in diameter were obtained. They were forging at the reduction ratios of 15%. After deformation, microstructure was evaluated by optical microscopy in each condition. Also, Vickers microhardness of samples was measured and phase constitution was evaluated using XRD analysis

Otimização de procedimentos de controle de qualidade em equipamentos radiográficos convencionais do Instituto de Eletrotécnica e Energia - USP

Radiography is currently an important method of diagnosis, both medical, dental and veterinary. The image in this type of survey is obtained using an X-ray beam, where the radiologist can possibly view structures of interest. It isn't always possible to get the desired images due to various factors, such as equipment limitations. The Administrative Law 453/98, the State Resolution SS 625/94, and other standards require testing and quality control acceptance limits that guarantee a good performance of the equipment for the security and quality of care, giving service users greater effectiveness in exams. This study were performed in the accompaniment of testing procedures for quality control established by Administrative Law 453/98 in several X-ray equipment to make a comparison and optimization in the descriptions of the procedures used by the Institute for Electrical Energy and the University of São Paulo (IEE / USP / SP).The optimization of the procedures were performed with the aid of a current literature, the Resolution 453/98, State Resolution SS 625/94 and other international standards. On this basis it was possible to observe the importance of regular monitoring of tests for an update, following the technological development of instruments used in the service

Aplicação da descarga por barreira dielétrica (DBD) em diferentes frequências no tratamento de polipropileno

In this work, air dielectric barrier discharge (DBD) operating at two different frequencies (60 Hz and 17 kHz) was used to improve surface properties of polypropylene (PP). The changes in surface hydrophilicity were investigated by contact angle measurements. The modifications in chemical composition of PP surface were studied by X-ray photoelectron spectroscopy (XPS) and Fourier-transformed infrared spectroscopy (FTIR). The PP roughness were analyzed before and after the DBD treatment using atomic force microscopy (AFM). In order to compare the results obtained at different frequencies, the analyses are presented as a function of the deposited energy density. The results show that both DBD treatments led to formation of low-molecular weight oxidized material (LMWOM). It tends to agglomerate into small mounts on the surface, as shown by AFM analyses. These structures are weakly bounded to the surface and can be easily removed by rinsing in polar solvents. After washing the DBD-treated samples, the PP partially recovers its original wetting characteristics. This suggests that oxidation also occurred at deeper and more permanent levels on the PP samples. Comparing both DBD treatments, the 17 kHz process was found to be more efficient in introducing oxygen groups to the PP surface

Checklist de cirurgias da OMS: análise da segurança e comunicação da equipe cirúrgica de um hospital escola

WHO has launched the “Safe Surgery Saves Lives” program with the purpose to reduce damage to surgical patients and define safety standards specifically in order to reduce such patients’ morbi-mortality by providing surgery teams and hospital managers with orientation about the standards of safe surgery and a uniform service evaluation instrument for national and international surveillance. Hence, this study aimed at applying the WHO safe-surgery checklist to the surgical specialties of a university hospital and evaluating the team’s opinion about the influence of its application on the safety of surgical process and on the team’s interpersonal communication. It was a descriptive, analytical, qualitative field study conducted in the surgery facilities of a university hospital in a public establishment in São Paulo state. The checklist was applied to eight surgical specialties, resulting in a total number of 30 surgeries. Its application was conducted by the researcher in three phases: Sign in, Time out, Sign Out. Next, one member of the surgery team was invited to voluntarily participate in the study by signing an informed consent form and answering guiding questions. Thirty members of the surgery team participated in the study. Bardin’s Content Analysis Method was used to organize and analyze the data. As regards the safety provided by the checklist, the following thematic categories emerged: “It reduces risk and possible complications”; “It standardizes conducts and reviews safety steps”; “It allows for better understanding of the process”; and “It provides safety to the team as a whole”. The category “It is not included in the institution’s routine” emerged from the subjects’ statements when they understood that, in this form, the checklist does not provide safety to surgical procedures. As regards communication, two thematic categories emerged: ...(Complete abstract click electronic access below)

Avaliação teórico-experimental da distribuição de dose absorvida em radioterapia em tumores de pele

O trabalho propõe rotinas computacionais usando o Método de Monte Carlo com o Código MCNP-5, para analisar os perfis de dose de radiação liberada nos tratamentos de tumores de pele e otimizar os cálculos radiométricos dos feixes de radiação estudados. Foram realizadas medidas dosimétricas do feixe de radiação, comparando os resultados obtidos com os respectivos valores fornecidos pelo serviço de física médica das instituições, com resultados informados pelo fabricante do equipamento e com as simulações computacionais efetuadas com o Código MCNP-5. A quantificação dos erros relativos percentual entre os resultados simulados e os fornecidos pelo Serviço de Radioterapia (E1), os informados pelo fabricante (E2) e os medidos experimentalmente (E3) são inferiores a 4,0% e validam a metodologia computacional proposta para avaliação do comportamento do feixe de raios-X superficial e do feixe de raios γ da unidade de Cobaltoterapia. A metodologia de análise do espectro energético e da curva de porcentagem de dose profunda (PDP) desenvolvida neste trabalho pode ser estendida para estudos de outros feixes clínicos e subsidiar os dados radiométricos utilizados nos planejamentos e cálculos de dose realizados pelo profissional da física médica na sua rotina nos Serviços de Radioterapia

Preparação e caracterização de filmes finos ferroelétricos nanoestruturados do tipo Pb1-x(Ca,Ba)xTiO3

O rápido crescimento do mercado de dispositivos eletrônicos portáteis, com aplicações em diferentes áreas (telecomunicações, medicina, engenharia), criou uma grande demanda por fontes de potência compactas leves e, sobretudo, de baixo custo. Essa demanda levou ao desenvolvimento de tecnologia de filmes finos nanoestruturados para a obtenção de componentes eletroeletrônicos, por exemplo, memórias de computador. Estes dispositivos são empregados em “notebooks”, circuitos integrados, telefones celulares. O estudo de cristalização de filmes finos ferroelétricos nanoestruturados será feito através da cristalização induzida por rotas convencionais tal como cristalização em forno mufla. A modulação entre os diferentes cátions (Pb, Ca e Ba) para formar o sistema Pb1-x(Ca,Ba)xTiO3 serão analisadas, visando obter filmes com propriedades compatíveis para uso em memórias ferroelétricas. Para isso, os filmes finos serão depositados em substratos adequados controlando-se a homogeneidade química, a microestrutura e a interação filme-substrato

Estudo das propriedades físicas em materiais vítreos do sistema 50B2O3 - 15CuO - 20Li2O - 15X (X= Na2O, K2O, RbCI e Cs2O)

The increasing demand for devices for solid state applications in many technological areas has resulted in a high demand for new materials. Among these material have the advantage of being manufactured with different chemical compositions, and may have physical properties equal to or higher than the corresponding crystalline material. The aim of this paper was to produce borate glass system 50B2O3 – 15CuO – 20Li2O – 15X (X = Na2O, K2O, RbCl e Cs2O) to analyze the influence of the atomic radius of alkali in the physical properties of this glass system. The glasses were synthesized by the process of melting and molding. The characteristic temperatures were determined by the technique of scanning calorimetry (DSC). The non-crystalline was determined by x-ray diffraction. In order to determine the molar volume a density measurement by using the Archimedes method was used. The structural characterization was carried out using the technique of infrared spectroscopy

Crescimeno de apatita na superfície da liga Ti-7, 5Mo empregando tratamento higrotérmico

The objective of the present work was to evaluate surface of experimental alloy Ti-7.5Mo after hydrothermal treatment. Ingots were obtained in arc melting furnace under an argon atmosphere and then homogenized under vacuum at 1100ºC for 86.4 ks to eliminate chemical segregation and after cold worked discs were cutting and grinding. For surface treatment, samples were immersed in a container with NaOH aqueous solution 5M, autoclaved, washed with distilled water. Followed, samples were heat treated and they were soaking in 5xSBF to form an apatite layer on the surface. Surfaces were investigated by, scanning electron microscopy, X-Rays powder diffraction, atomic force microscopy and contact angle, in order to evaluate the wettability of the alloy surface. The results were compared with our previous studies using the group of chemical surface treatments and results shows better condition is 120 minutes in the autoclave

Avaliação da Taxa de Exposição em Exames Radiológicos Realizados em Procedimentos Cirúrgicos - Minimização dos Riscos em Indivíduos Ocupacionalmente Expostos

This paper consists in the evaluation of the exposure rate to ionizing radiation to which professionals working in surgical procedures which require radiological examinations are subjected. Were initially performed real-time readings of exposure rate within four distinct operating rooms during the execution of four surgical procedures that made use of fluoroscopy equipment (including three orthopedic surgeries, one in the shoulder, one in the arm, another for deployment of metal pin in the leg region, and a fourth for vascular procedure); in these surgeries were used ionization chamber detector and an electrometer. In order to check the values achieved, was made a re-evaluation of the distribution of the rate of exposure to radiation, from the surgical procedures, now with thermoluminescent dosimeters (TLDs). For this, thirty TLDs were distributed in the operating rooms, arranged in points of interest as occupation by professionals. The TLDs were prepared for thirty consecutive days, after which they were removed and replaced with new dosimeters not exposed yet. The dosimeters were subjected to reading of the rate of exposure; this procedure was repeated for four months without interruption. The quantification of the results sought primarily to convert the rate of exposure for equivalent dose rate, both in measurements with ionization chamber as in measurements with TLDs, in order to highlight the presence of the biological effect of ionizing radiation for comparisons within scientific context. Then, the results were plotted to establish the relationship between the values of equivalent dose and the distance to the central axis of the x -ray source, confirming the inverse square law for distance. Finally, the values were associated with the maximum limit recommended by the legislation for occupationally exposed individuals. The methodology for the analysis and quantification of the data in this work aims at implementing a work plan that meets ...

Estudo do desempenho de filmes de Ti02 como aceptor de elétrons e obtenção de fases puras de nanopartículas de Ti02: anatase e rutila, sintetizado por uma nova rota química

Pós-graduação em Ciência dos Materiais - FEIS

Obtenção de rochas sintéticas a partir de resíduos de vidro comercial e pó de granito

Pós-graduação em Engenharia Mecânica - FEG

Análise estrutural e bioquímica da hidroxiapatita submetida ao tratamento com fluoreto e polifosfatos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da superfície do carbono vítreo reticulado após tratamento de implantação iônica por imersão em plasma (3IP) para a obtenção de eletrodos

In this work, RVC samples were treated by plasma immersion ion implantation (PIII) for electrodes production. High-voltage pulses with amplitudes of -3.0 kV or -10.0 kV were applied to the RVC samples while the treatment time was 10, 20 and 30 minutes. Nitrogen, atmospheric air and H2:N2 mixture were employed as plasma sources. The samples were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. The SEM images present an apparent enhancement of the surface roughness after the treatment probably due to the surface sputtering during the PIII process. This observation is in agreement with the specific electrochemical surface area (SESA) of RVC electrodes. An increase was observed of the SESA values for the PIII treated samples compared to the untreated specimen. Some oxygen and nitrogen containing groups were introduced on the RVC surface after the PIII treatment. Both plasma-induced process: the surface roughening and the introduction of the polar species on the RVC surface are beneficial for the RVC electrodes application

Segurança em redes sem fio: estudo sobre o desenvolvimento de conjuntos de dados para comparação de IDS

Pós-graduação em Engenharia Elétrica - FEIS

Controle da porosidade e das características ácido-base de óxidos mistos derivados da hidrotalcita para aplicação em catálise

Pós-graduação em Química - IQ