RESUMO As telhas de aço usadas em galpões de fazendas expostas às intempéries ficam vulneráveis à degradação. A corrosão surge devido à diferença de potencial elétrico entre a superfície metálica e o meio, levando a um carregamento elétrico dessa superfície. Elas então necessitam da proteção de um recobrimento anticorrosivo, cujo objetivo é aumentar sua vida útil. Atualmente um recobrimento usado para diminuir os efeitos do sol e da chuva em telhas metálicas é o de zincalume, que consiste em uma liga de zinco e alumínio. Este recobrimento permite a combinação do zinco com alumínio, que alia a resistência por barreira do primeiro ao bom desempenho do segundo em proteger bordas e pequenas descontinuidades. Este produto mantém a força estrutural do aço-base e confere alta resistência à corrosão atmosférica, interrompendo a corrente elétrica. Neste trabalho foi analisada a degradação das telhas de aço recobertas com uma camada de zincalume sujeita à ação do tempo. Análises com fluorescência de raios X foram utilizadas a fim de se verificar a composição química das amostras estudadas. Foram realizadas também análises macrográficas e micrográficas, a fim de se avaliar a degradação das telhas.

ABSTRACT The steel roof tiles used in farm sheds are vulnerable to the action of weathering. The corrosion arises due to difference of electrical potential between the metallic surface and the environment, leading to an electrical load of this surface. They need a protection, an anticorrosive coating, whose purpose is to increase the lifetime. Zincalume is a kind of coating currently used to decrease the effects of sun and rain in the metal roof tiles. This coating consists of an alloy of zinc and aluminum. The Zincalume coating allows the combination of zinc and aluminum by combining the barrier resistance offered by the first one and the good performance of the second one in protecting edges and small discontinuities. This product maintains the structural strength of the steel base and provides high resistance to atmospheric corrosion leading to the interruption of the electrical current. The degradation of steel roofing coated with a layer of zincalume subject to weathering was analyzed in this work. Analysis with X-ray fluorescence was used to verify the chemical composition of the studied samples. Macrographic and micrographic analyzes were also carried out in order to evaluate the degradation of the roof tiles.

This work deals with the deposition of a thin layer of porous silica antireflective coating onto glass substrates. The films were deposited with different withdrawal speeds and heat-treated at 425°C for 30 minutes. The effects of heat treatment and film deposition rate on the films reflectance were evaluated. The diffuse reflectance was measured using ultraviolet-visible (UV-Vis) spectroscopy. Scanning electron microscopy (SEM) was used for microstructural evaluation of the films. The water contact angle upon the films surface was evaluated using a tensiometer and was based on the sessile drop technique. The mechanical characteristics of the films were evaluated by tape test and pencil hardness. The obtained sol-gel silica coatings were homogeneous and free of cracks. UV-Vis analysis of the glass substrate revealed a reflectance value of 3.86%, whereas the lowest reflectance value obtained for antireflective coatings was 2.72%. The contact angle measurement showed that, for all films, there was wetting of the film by water, characterizing them as hydrophilic. The adhesion of the films were 4B and the pencil hardness were 3H.

One of the applications of selective surfaces is to improve performance of solar absorbers. The purpose of this work is to produces selective coatings with high absorption of solar radiation in the range of UV/Vis/NIR. It was prepared a selective surface composed of black chromium (Cr/Cr2O3) deposited on substrates of AISI 304 stainless steel using the technique of electrolytic deposition for application in solar thermal absorbers. The great parameters for deposition consisted of a continuous electric current of 2A for 90s, at a constant temperature of 40°C. After deposition, the samples under went to a heat treatment at 600°C for 2h for oxidation. The coatings thicknesses were determined. From the SEM analysis coupled with EDS, it was found that the microstructures reported sample of cermets. The XRD results show diffraction peaks related to metallic chromium (Cr) and chromium oxide (Cr2O3). Spectral absorptance values more 90.0% were found.

Este estudo visa analisar alterações em variáveis enzimáticas, psicométricas e hematológicas durante um microciclo de uma pré-temporada no futebol profissional, a fim de verificar quais parâmetros são mais sensíveis às cargas de treinamento. Foram avaliados oito atletas do sexo masculino antes do treinamento (M1) e após 14 sessões (M2). Após testar a normalidade dos dados, foi realizado o teste t-Student pareado para calcular as diferenças entre M1 e M2. Nos marcadores hematológicos, foi observada a queda nos eritrócitos (p = 0,01), hemoglobina (p = 0,02) e hematócrito (p = 0,01). Enquanto que nos enzimáticos, observou-se aumento da CK (p = 0,001) e LDH (p = 0,01). A CK é a variável que melhor respondeu à carga de treino em curto prazo, enquanto que a LDH, hematócrito, hemoglobina e eritrócito são potenciais variáveis, podendo auxiliar no entendimento das respostas da CK no monitoramento dos treinamentos, permitindo o aprimoramento dos mesmos.

The purpose of the study was to analyze changes in enzymatic, psychometric and hematological variables during a microcycle of a pre-season in professional soccer, to verify which of these parameters are more sensitive to training loads. Eight male athletes were evaluated before training (M1) and after 14 sessions (M2). After testing the data normality, we performed a paired Student t-test to calculate differences between M1 and M2. In hematological markers, a decrease was observed in erythrocytes (p = 0.01), hemoglobin (p = 0.02) and hematocrit (p = 0.01). Relative to the enzyme, there was an increase of CK (p = 0.001) and LDH (p = 0.01). CK was the variable that best responded to the training load in the short-term, while the LDH, hematocrit, hemoglobin and erythrocytes were potential variables, which could help in understanding the CK responses in the monitoring of training, allowing its improvement.

O artigo versa sobre a contribuição de avaliação in loco no sentido de promover a consolidação dos princípios norteadores do SINAES a partir de uma reflexão construtiva entre os consultores ad hoc e a instituição. A digressão teórica elenca aspectos relacionados a construção da identidade institucional, a partir da contribuição da avaliação e o retrospecto da avaliação institucional no Brasil. Elenca, ainda uma reflexão sobre o modelo do SINAES e os princípios estruturantes e norteadores do Sistema, destacando a contribuição do processo de avaliação in loco na construção da epistemologia institucional. Para tanto, as interações metodológicas ocorrem sob as bases da pesquisa acadêmica, de caráter documental indireto e que se classifica como sendo descritiva-explicativa, predominantemente qualitativa e designada como sendo uma pesquisa participante. As investigações construtivistas permitem concluir, entre outros desígnios, que do ponto de vista dos avaliadores ad hoc os aspectos que determinam o cumprimento dos princípios estruturantes do SINAES no contexto da avaliação institucional das instituições de educação superior no Brasil ensejam uma relação construtivista, democrática e de aprendizado mutuo e continuo entre avaliadores e a própria instituição, a qual é a responsável pela consolidação destes princípios no âmbito do ensino superior brasileiro.

The paper focuses on the contribution of on-site evaluation in order to promote the consolidation of the guiding principles of SINAES based on the constructive thinking of consultants and the ad hoc institution. The theoretical discussion presents aspects related to the construction of institutional identity, based on the contribution of evaluation and on the definitions of institutional evaluation in Brazil. It also discusses Sinaes as a model along with the guiding principles that structure the System, emphasizing the contribution of the on-site evaluation process on the construction of institutional epistemology. Methodological interactions occur on the bases of academic research, of indirect documental character, which can be classified as descriptive-explanatory, predominantly qualitative and designed as participative research. The constructivist investigations allow us to conclude, among other things, that, from the standpoint of the peer review panel, the aspects that determine the compliance with the structural principles of Sinaes in the context of the institutional evaluation of higher education institutions in Brazil promote a constructivist and democratic relationship of mutual and continuous learning between evaluators and the institution itself, which is responsible for consolidating these principles in Brazilian higher education.

FUNDAMENTO: O teste de exercício de 4 segundos (T4s) avalia o tônus vagal cardíaco durante o transiente inicial da frequência cardíaca (FC), em exercício dinâmico súbito, por meio da identificação do índice vagal cardíaco (IVC) obtido a partir do eletrocardiograma (ECG). OBJETIVO: Testar a utilização do monitor de frequência cardíaca (MFC) Polar S810 como recurso alternativo ao ECG na aplicação do T4s. MÉTODOS: Neste trabalho, 49 indivíduos do sexo masculino (25 ± 20 anos, 176 ± 12 cm, 74 ± 6 kg) realizaram o T4s. Os intervalos RR foram registrados simultaneamente por ECG e MFC. Calcularam-se média e desvio padrão do último intervalo RR do período pré-exercício ou o primeiro do período de exercício, aquele que for mais longo (RRB), do mais curto intervalo RR do período de exercício (RRC) e do IVC obtidos por ECG e MFC. Utilizou-se o teste t de Student para amostras dependentes (p < 0,05) para testar a significância das diferenças entre as médias. Para identificar a concordância entre o ECG e o MFC, utilizou-se a regressão linear, com cálculo do coeficiente de correlação de Pearson e a estratégia proposta por Bland e Altman. RESULTADOS: A regressão linear apresentou r² de 0,9999 para o RRB, 0,9997 para o RRC e 0,9996 para o IVC. A estratégia de Bland e Altman apresentou desvio padrão de 0,92 ms para o RRB, 0,86 ms para o RRC e 0,002 para o IVC. CONCLUSÃO: O MFC Polar S810 se mostrou eficiente na aplicação do T4s quando comparado ao ECG.

BACKGROUND: The 4-second exercise test (T4s) evaluates the cardiac vagal tone during the initial heart rate (HR) transient at sudden dynamic exercise, through the identification of the cardiac vagal index (CVI) obtained from the electrocardiogram (ECG). OBJECTIVE: To evaluate the use of the Polar S810 heart rate monitor (HRM) as an alternative resource to the use of the electrocardiogram in the 4-second exercise test. METHODS: In this study, 49 male individuals (25 ± 20 years, 176 ±12 cm, 74 ± 6 kg) underwent the 4-second exercise test. The RR intervals were recorded simultaneously by ECG and HRM. We calculated the mean and the standard deviation of the last RR interval of the pre-exercise period, or of the first RR interval of the exercise period, whichever was longer (RRB), of the shortest RR interval of the exercise period (RRC), and of the CVI obtained by ECG and HRM. We used the Student t-test for dependent samples (p < 0.05) to test the significance of the differences between means. To identify the correlation between the ECG and the HRM, we used the linear regression to calculate the Pearson's correlation coefficient and the strategy proposed by Bland and Altman. RESULTS: Linear regression showed r² of 0.9999 for RRB, 0.9997 for RRC, and 0.9996 for CVI. Bland e Altman strategy presented standard deviation of 0.92 ms for RRB, 0.86 ms for RRC, and 0.002 for CVI. CONCLUSION: Polar S810 HRM was more efficient in the application of T4s compared to the ECG.

FUNDAMENTO: El test de ejercicio de 4 segundos (T4s) evalúa el tono vagal cardíaco durante el transiente inicial de la frecuencia cardíaca (FC), en ejercicio dinámico súbito, por medio de la identificación del índice vagal cardíaco (IVC) obtenido a partir del electrocardiograma (ECG). OBJETIVO: Probar la utilización del monitor de frecuencia cardiaca (MFC) Polar S810 como recurso alternativo al ECG en la aplicación del T4s. MÉTODOS: En este trabajo, 49 individuos del sexo masculino (25 ± 20 años, 176 ±12 cm, 74 ± 6 kg) llevaron el T4s. Los intervalos RR fueron registrados simultáneamente por ECG y MFC. Se calcularon el promedio y la desviación estándar del último intervalo RR del período pre ejercicio o el primer del período de ejercicio, aquel que fuera más largo (RRB), del más corto intervalo RR del período de ejercicio (RRC) y del IVC obtenidos por ECG y MFC. Se utilizó la prueba t de Student para muestras dependientes (P < 0,05) para probar la significancia de las diferencias entre los promedios. Para identificar la concordancia entre el ECG y el MFC, se utilizó la regresión lineal, con cálculo del coeficiente de correlación de Pearson y la estrategia propuesta por Bland y Altman. RESULTADOS: La regresión lineal expresó r² de 0,9999 para el RRB, 0,9997 para el RRC y 0,9996 para el IVC. La estrategia de Bland y Altman expresó desviación estándar de 0,92 ms para el RRB, 0,86 ms para el RRC y 0,002 para el IVC. CONCLUSIÓN: El MFC Polar S810 se halló eficiente en la aplicación del T4s cuando comparado al ECG.

Recobrimentos de Ni/NiO em substrato de alumínio têm sido utilizados para se desenvolverem superfícies seletivas com alto desempenho para aplicações fototérmicas. Industrialmente essas superfícies têm sido empregadas em coletores solares. No presente trabalho, amostras de alumínio foram recobertas com Ni/NiO por processos químico e eletrolítico seguidos de tratamento térmico para oxidação. Os filmes foram produzidos em camada dúplex, sendo a primeira constituída de Ni e a segunda de NiO, a camada de anti-reflexão (AR). As espessuras dos filmes depositados têm cerca de 1,0µm. As microestruturas das amostras foram examinadas ao microscópio eletrônico de varredura (MEV). Análises de difração de raios X (DRX) identificaram as fases presentes. As amostras foram caracterizadas quanto às propriedades óticas nas regiões do visível e do infravermelho próximo. A absortância solar média dos recobrimentos eletrolíticos oxidados atingiu picos de 97,5%, enquanto a refletância no infravermelho distante foi de 12%.

The investigation of Ni/NiO coatings in aluminum substrate has been realized to develop high performance selective surfaces for photothermal applications. These absorber surfaces have been designed for industrial production. The present work describes Ni/NiO coatings in aluminum substrate obtained by chemical and electrolytic processes. Thermal treatments were used for oxidation. The first layer is Ni, the second one is NiO, the layer is an antireflectant (AR). The layer thicknesses are 1.0µm. The microstructures of the samples were examined by scanning electronic microscope (MEV). The X-ray diffraction (XRD) was used to identify the present phases. The optical properties, in some regions of visible and near infrared, allowed peaks of 97,5% for solar absorption and reflection of 12% for the electrolytic process oxidation.

The effects of combustion thermal spraying parameters namely combustion pressure, feeding rate, and carrier gas on the wear resistance, friction coefficient, and Knoop hardness of poly (ethylene terephthalate) (PET) films were investigated. The PET coatings were characterized by measuring the wear coefficients by calowear-type testing, the friction coefficients by a pin-on-disk test, and Knoop hardness. The abrasive wear and friction coefficients of the coatings were compared with the values of a post consumer PET bottle chip reference sample. The structural characteristics of the coatings were investigated by X ray diffraction. Statistical analysis of the results allowed for the systematic characterization of the influence of the process variables mentioned above on the coating wear, friction, and microhardness values. Specifically, this study shows that the process parameters affect the wear coefficient and Knoop hardness significantly, but not the friction coefficient. The degree of crystallinity of the PET coatings varied from 20 to 26%.

A aspersão térmica envolve processos de recobrimentos que podem utilizar materiais cerâmicos, poliméricos, metálicos ou misturas destes. O material a ser depositado é fundido total ou parcialmente. As partículas aquecidas são aceleradas e projetadas em direção a uma superfície devidamente preparada, onde se formam camadas com estrutura lamelar. Os efeitos das variáveis do processo de aspersão, pressão dos gases de combustão, taxa de alimentação e gás de arraste no transporte do material, sobre a resistência ao desgaste e atrito de filmes PET foram investigados. Os recobrimentos de PET foram caracterizados através do desgaste micro-abrasivo, utilizando o ensaio de caloteste, e da medida dos coeficientes de atrito, com o ensaio de pino-sobre-disco. Os valores do coeficiente de desgaste abrasivo e do coeficiente de atrito dos recobrimentos são comparados com os valores da garrafa PET utilizada como referência. Os coeficientes de desgaste encontrados foram similares aos valores de garrafas PET da ordem de 10-5. As análises estatísticas dos resultados deste trabalho indicam que os efeitos das interações das três variáveis, pressão dos gases de combustão, taxa de alimentação e gás de arraste foram significativos para o coeficiente de desgaste e não significativos para o coeficiente de atrito.

The thermal spray technique involves coating processes that can use ceramic, polymers, metallic materials or a blend of these. The material to be deposited is melted totally or partially, where the heated particles are accelerated and projected toward a prepared surface forming layers with a lamellar structure. The effect of the spray process parameters such as, combustion pressure, feed rate and carrier gas, on the wear resistance and friction of PET films was evaluated. The PET coatings were characterized by measuring the wear coefficient through the calowear type testing and the friction coefficients using pin-on-disk testing. The values of the abrasive wear coefficient and the friction coefficient of the coatings were compared to the values of the bottle PET reference sample. The wear coefficient values were similar to the values for the PET bottles, in the range of 10-5. The statistical analyses of the results indicate that the interaction effects of the three variables, gas pressure, feeding rate and carrier gas were significant for the wear coefficient but not for the friction coefficient.

In early 2003, the Brazilian government accelerated the decision process on analog to digital transition of terrestrial TV broadcast infrastructure, naming this initiative The Brazilian Digital Television System (SBTVD). This paper describes the access device architecture we have proposed for the SBTVD, as well as related issues. We focused on several requirements among which: flexibility to support the social economical diversity enabling market implementations that can vary on cost, complexity and applications; digital inclusion targeting a minimal cost architecture providing a simple access device to information and services by convergent broadcast and point-to-point telecommunication means; and scalability targets incorporating state-of-the-art technology, considering emerging services and the current legacy analog TV infrastructure available in Brazil. We cover the following specific topics: an architecture overview considering scalability, interoperability and regional and international requirements, operating system and middleware interfaces, audio and video coding formats and associate standards, technical and economical analysis, usability and user interface consistency. Finally two prototypes for the outlined access device architecture are reported.

Recobrimentos químicos de Ni-P têm sido observados em diversas aplicações, tais como ferramentas e matrizes, principalmente em condições de desgaste e em situações de corrosão. No presente trabalho, recobrimentos químicos de Ni-P com 8 e 10%P foram depositados, quimicamente, em aço ABNT 1020 e, posteriormente, tratados, termicamente, entre 300°C e 650°C por 1 hora. As microestruturas níquel e fosfetos foram examinadas ao microscópio eletrônico de varredura (MEV). Análises de calorimetria diferencial de varredura (DSC) foram realizadas para detectar reações e transformações de fases. Resultados do ensaio de riscamento constataram uma variação da adesão desses recobrimentos em função da temperatura de tratamento térmico, bem como da dureza ao risco, que atingiu um valor máximo a 400ºC.

Chemical coatings of Ni-P have been observed in various applications, such as, tools, molds and matrices, mainly to prevent wear and corrosion. In this present work, Ni-P coatings with 8 and 10%P were deposited on steel ABNT 1020 and heat-treated at temperatures between 300ºC and 650ºC for 1h. The microstructures, nickel and phosphates have been examined using a scanning electronic microscope (SEM). Analyses of Differential Scanning Calorimetry (DSC) has been carried out to detect reactions and transformations of the phases. The results of assay scratch revealed a variation of the adhesion of these coatings in function of the heat treatment temperature, as well as of the hardness to the scratch that reached a maximum value to 400ºC.

Surveillance programs are essential to detect the increase of antimicrobial resistance, and several different programs are being conducted in many countries. The RESISTNET is a surveillance program for bacterial resistance against several antimicrobial agents initiated in 1998 among Latin American countries. In Brazil, several centers were invited to join this surveillance and a total of 11 centers (6 from São Paulo and 5 from other states) participated in the study. All results were analyzed using the WHONET program. A total of 894 Escherichia coli, 386 Klebsiella pneumoniae, 70 Shigella spp and 57 Salmonella spp strains were analyzed in this study from April, 1998, to April, 1999. Susceptibility testing was performed by the disk diffusion method using NCCLS 1998 guidelines for several different drugs. For all strains, imipenem was the most effective drug (100% of the strains were susceptible). Klebsiella pneumoniae presented a high resistance rate to ampicillin (96.4%). The rate of probable ESBL producers among K. pneumoniae strains was 36.3%, most of them being isolated from catheters (58.8%). Among all Escherichia coli strains analyzed, the highest resistance rate was found for trimethoprim/sulfamethoxazole (46.9%) and the majority of the resistant strains were isolated from urine samples (47.8%). Among Salmonella spp, the resistance rates were low for all antibiotics tested. For Shigella spp strains there was a high resistance to trimethoprim/sulfamethoxazole (80.0%). No resistance to ceftriaxone was observed in these strains. Surveillance of antimicrobial resistance is critical for the successful management of infectious diseases. The results of this survey show significant resistance rates among these bacteria which are responsible for several types of human infections.