Caracterização de superfícies de titânio modificado por oxidação à plasma

Recent years have seen a significant growth in surface modifications in titanium implants, resulting in shorter healing times in regions with low bone density. Among the different techniques, subtraction by chemical agents to increase oxidation has been applied for surface treatment of dental implants. However, this technique is generally unable to remove undesirable oxides, formed spontaneously during machining of titanium parts, raising costs due to additional decontamination stages. In order to solve this problem, the present study used plasma as an energy source to both remove these oxides and oxidize the titanium surface. In this respect, Ti disks were treated by hollow cathode discharge, using a variable DC power supply and vacuum system. Samples were previously submitted to a cleaning process using an atmosphere of Ar, H2 and a mixture of both, for 20 and 60 min. The most efficient cleaning condition was used for oxidation in a mixture of argon (60%) and oxygen (40%) until reaching a pressure of 2.2 mbar for 60 min at 500°C. Surfaces were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), adhesion and cell proliferation. SEM showed less cell spreading and a larger number of projections orfilopodia in the treated samples compared to the control sample. AFM revealed surface defects in the treated samples, with varied geometry between peaks and valleys. Biological assays showed no significant difference in cell adhesion between treated surfaces and the control. With respect to cell proliferation, the treated surface exhibited improved performance when compared to the control sample. We concluded that the process was efficient in removing primary oxides as well as in oxidizing titanium surfaces

Taxa de emissão de CO2 de um latossolo fertirrigado com ácido fosfórico por gotejamento

A aplicação de fertilizantes fosfatados por meio de fertirrigação com sistemas de irrigação localizada pode causar obstrução de emissores. Para evitar esse problema, pode ser utilizado o ácido fosfórico como fonte de fósforo às plantas. Porém, têm sido pouco investigados os efeitos da irrigação relacionados às perdas de CO2 do solo para a atmosfera, em conseqüência da decomposição do carbono orgânico e da infiltração de água no solo. Neste trabalho, investigou-se, no período de um mês, o efeito da fertirrigação com ácido fosfórico nas taxas de emissão de CO2 de um latossolo desprovido de vegetação, na Área Experimental de Irrigação da UNESP, Câmpus de Jaboticabal - SP. Utilizou-se de um sistema de irrigação por gotejamento, com delineamento experimental em blocos casualizados, constando de cinco repetições e cinco tratamentos (0; 30; 60; 90 e 120 kg ha-1de P2O5), aplicados via fertirrigação com ácido fosfórico. Verificou-se que as taxas de emissão de CO2 aumentaram significativamente após as fertirrigações, porém não houve efeito da dose do ácido fosfórico sobre as taxas. A umidade do solo mostrou-se um fator importante na relação entre as variações das taxas de emissão e a temperatura do solo ao longo do período estudado.

Estudo da radiação ultravioleta na Cidade de Natal-RN

There were studied the variation of the solar ultraviolet radiation (UVR) in four wavelengths (305 nm, 320 nm, 340 nm e 380 nm) and erythemic dose, measured in Natal RN Brazil, from January 2001 until December 2007, using the ground ultraviolet radiometer of the Instituto Nacional de Pesquisas Espaciais / Centro Regional do Nordeste INPE-CRN, fixed on the roof of the Laboratório de Variáveis Ambientais Tropiciais LAVAT-INPE-CRN. It was verified that the mean value of the UVR in the city reachs the HIGH index before 09h00 a.m. and VERY HIGH before 09h40 a.m.; it was also verified that, except in the months of June and July, in the other months of the year the UVR reachs the HIGH index before 10h00 a.m., despite of the recommendations broadcasting in the media about the safe time to people stay ashore on the beaches of the city. After 14h30 p.m., the UVR reachs the MODERATE index in any month of the year. These evidence are valid to all years of the period studied, i.e., 2001 to 2007. The year of 2004 presented the lower mean values of UVR indices, and the year of 2007 presented the higher mean values of UVR index. It was prove, by means of the analysis of variance (ANOVA), the variation in the four wavelengths and in the erythemic dose. Considering that the city has high indices of skin cancer and cataract, the results of the research may be use as a data source to studies that intend to support programs of public health. At the same time, the results of the research may be applied to material science and agriculture studies

Com o olhar nos professores: Desafios para o enfrentamento das realidades escolares

A escola tem sido crescentemente focalizada, não só no Brasil, mas em outros países, constituindo importante fonte para a compreensão das realidades vividas e sofridas pela grande maioria das populações mais privilegiadas econômica, social e culturalmente. A bibliografia produzida pelos autores de tais estudos denuncia, de maneira contundente, a baixa qualidade educacional em vários países, expressa por problemas como indisciplina na sala de aula, precárias condições para o trabalho educativo, despreparo dos professores para realizar adequadamente seu trabalho, baixo status profissional e baixa remuneração, agravados no Brasil pelos alarmantes índices de evasão e repetência. Com o olhar nos professores, como comprometimento político e preocupação de pesquisa, desde o ano de 1984, nossos estudos permitem dizer que esse quadro de problemas não constitui um insucesso generalizado, mas representa, sobretudo, desafios a enfrentar.

Uso urbano não potável de água de lagoas do sistema de drenagem de Natal

The detention and infiltration ponds of urban drainage system has function to protect the population from undesirable effects of floods. In general these ponds are not completly used and it potential is wasted. As it are disseminated at different places at cities it can reduce costs with water transport and permit water preservation of best quality. Some it utilities includes use in green areas irrigation, industrial among than cooling towers and boiler, soil compaction, cleaning urban road, pisciculture and fire fighting system. The quality these water is influenced by anauthorized sewage in the drainage system. This study was performed in six detention and infiltration ponds at drainage system of Natal, which aim was to verify the non-portable use these ponds on urban environment. As indirect aim would to incentive the water utilization these ponds as a water source to another uses in urban environment. These ponds represents the characteristics of detention and infiltration of Natal city and consequently of Brazil. As the water quality, the ponds presents following characteristics: three has apparently good quality, other showed intermediate condition and two had water polluted. Were performed twenty sample in each ponds and the following parameters assessed: pH, temperature, dissolved oxygen, turbidity, electrical conductivity, coliform thermotolerant, ammonia, organic nitrogen, TKN, nitrate, total phosphorus and alkalinity, bicarbonate, chloride, total hardness, calcium and magnesium hardness, total solids, TSS, TDS, COD and SAR°. To utilization on pisciculture we recommend use in ponds which presents the best quality. Only one pond presented higher pollutants and it not being appropriated for use in cooling tower. The content of solids suspension restricted the water use in all ponds in boilers. As water use in soil compaction, cleaning urban road and fire fighting system the water from these ponds are not appropriated. However, the recommended limits from literature are to domestic sewage, due to this, the parameters are restrictive to diminish the sanitary risk that could be offered with it utilization. The infiltration velocity of water these assessed ponds restrict a moderato use, however the effects are potentiated only in soil less sandy, which not occur in Natal. It is recommend the unrestricted irrigation utilization in ponds with best quality of water, and a restricted irrigation to ponds with worst quality of water. As load of pollutants, it is recommended a complementary treatment in those ponds whit higher load to diminish sanitary risks. In only one pond was found one helminth eggs and due to the convention formula of results, it was found for all ponds less than 1 helminth/liter eggs.

A modalização como estratégia argumentativa em textos de vestibulandos

In this work, the argumentative strategies construction in university entrance examinations texts is analyzed. The study intended to present, through the analyzed occurrences in the corpus, the discursive strategies use for the argumentation construction, observing the different lexicalization forms and the effects that these strategies produced for the intended meaning construction. Aiming to analyze the modalization via texts written by candidates for the UFRN entrance examination, the relations between this category and the resources used for the argumentative guidance of the text were highlighted. Conceived as a speaker argumentative strategy to express his/her relationship with the proposition content which enunciates, the modalization is, thus, one of the linguistic expression form used for the attainment of intended meaning effects in the argumentation construction. In order to substantiate the research, the theoretical assumptions adopted were the propositions which deal with this linguistic category, guiding it to a pragmatic-semantic perspective as well as a discursive-semantic one. Hence, Neves ( 1996, 2006), Koch ( 2000, 2002), Cervoni ( 1989), Bronkart (1999) and Castilho; Morais de Castilho (1996) studies, among others founded this work. Afterwards, a contextualized analysis of the modalized statements, taking into account all the set of elements implied on the argumentation construction, was carried out. The research, which had a strict qualitative character, revealed that the candidates make use of modalization to express commitment or dissociation as regards the statement which they produce; to obtain credibility and provide more authority to their arguments, thus avoiding them of being contested; to impose their arguments as real ones and acquire acceptance of the interlocutor; to lessen the proposition content and disguise the knowledge source; to comment the enunciation and attribute the discourse to another sender; to establish a dialogic relation with the interlocutor. In addition to offering support for new investigations, the research also aims to contribute for the mother tongue teaching, emphasizing the need of a focus which provides special attention to the written language functioning and its application diversity. In this work, the argumentative strategies construction in university entrance examinations texts is analyzed. The study intended to present, through the analyzed occurrences in the corpus, the discursive strategies use for the argumentation construction, observing the different lexicalization forms and the effects that these strategies produced for the intended meaning construction. Aiming to analyze the modalization via texts written by candidates for the UFRN entrance examination, the relations between this category and the resources used for the argumentative guidance of the text were highlighted. Conceived as a speaker argumentative strategy to express his/her relationship with the proposition content which enunciates, the modalization is, thus, one of the linguistic expression form used for the attainment of intended meaning effects in the argumentation construction. In order to substantiate the research, the theoretical assumptions adopted were the propositions which deal with this linguistic category, guiding it to a pragmatic-semantic perspective as well as a discursive-semantic one. Hence, Neves ( 1996, 2006), Koch ( 2000, 2002), Cervoni ( 1989), Bronkart (1999) and Castilho; Morais de Castilho (1996) studies, among others founded this work. Afterwards, a contextualized analysis of the modalized statements, taking into account all the set of elements implied on the argumentation construction, was carried out. The research, which had a strict qualitative character, revealed that the candidates make use of modalization to express commitment or dissociation as regards the statement which they produce; to obtain credibility and provide more authority to their arguments, thus avoiding them of being contested; to impose their arguments as real ones and acquire acceptance of the interlocutor; to lessen the proposition content and disguise the knowledge source; to comment the enunciation and attribute the discourse to another sender; to establish a dialogic relation with the interlocutor. In addition to offering support for new investigations, the research also aims to contribute for the mother tongue teaching, emphasizing the need of a focus which provides special attention to the written language functioning and its application diversity

Uso do sensoriamento remoto orbital no monitoramento da dispersão de macrófitas nos reservatórios do complexo Tietê

A presença de algumas substâncias na água, como pigmentos fotossintetizantes, particulados, etc., afeta sua cor, provocando mudanças na radiância da água registrada por sensores orbitais. Nesse sentido, o sensoriamento remoto pode se constituir em uma fonte complementar de dados para o monitoramento da qualidade da água em grandes reservatórios (Novo et al., 1994). No contexto de um projeto de pesquisa realizado na AES Tietê S.A., com o objetivo de desenvolver técnicas para a avaliação da área com infestação de plantas aquáticas, imagens orbitais multiespectrais foram usadas tanto para mapear a dispersão espacial e estimar a área de ocorrência de macrófitas aquáticas, em duas épocas distintas, quanto para orientar a definição de pontos de amostragem in loco, visando a coleta e posterior análise da água e de sedimentos nos reservatórios. Este trabalho apresenta uma descrição do procedimento metodológico adotado na análise das imagens multiespectrais, bem como os resultados obtidos na caracterização dos reservatórios de Barra Bonita, Bariri, Ibitinga, Promissão e Nova Avanhandava, em termos de seu dimensionamento, variabilidade espectral da água e presença de macrófitas emersas, nas duas épocas do ano consideradas.

Detection of nontuberculous mycobacteria from water buffalo raw milk in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Projeto de Sistemas Integrados de Propósito Geral Baseados em Redes em Chip Expandindo as Funcionalidades dos Roteadores para Execução de Operações: A plataforma IPNoSys

It bet on the next generation of computers as architecture with multiple processors and/or multicore processors. In this sense there are challenges related to features interconnection, operating frequency, the area on chip, power dissipation, performance and programmability. The mechanism of interconnection and communication it was considered ideal for this type of architecture are the networks-on-chip, due its scalability, reusability and intrinsic parallelism. The networks-on-chip communication is accomplished by transmitting packets that carry data and instructions that represent requests and responses between the processing elements interconnected by the network. The transmission of packets is accomplished as in a pipeline between the routers in the network, from source to destination of the communication, even allowing simultaneous communications between pairs of different sources and destinations. From this fact, it is proposed to transform the entire infrastructure communication of network-on-chip, using the routing mechanisms, arbitration and storage, in a parallel processing system for high performance. In this proposal, the packages are formed by instructions and data that represent the applications, which are executed on routers as well as they are transmitted, using the pipeline and parallel communication transmissions. In contrast, traditional processors are not used, but only single cores that control the access to memory. An implementation of this idea is called IPNoSys (Integrated Processing NoC System), which has an own programming model and a routing algorithm that guarantees the execution of all instructions in the packets, preventing situations of deadlock, livelock and starvation. This architecture provides mechanisms for input and output, interruption and operating system support. As proof of concept was developed a programming environment and a simulator for this architecture in SystemC, which allows configuration of various parameters and to obtain several results to evaluate it

Ground annatto seeds (Bixa orellana L.) in sorghum-based commercial layer diets and their effects on performance, egg quality, and yolk pigmentation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dissipation-managed soliton in a quasi-one-dimensional Bose-Einstein condensate

We use the time-dependent mean-field Cross-Pitaevskii equation to study the formation of a dynamically-stabilized dissipation managed bright soliton in a quasi-one dimensional Bose-Einstein condensate (BEC). Because of three-body recombination of bosonic atoms to molecules, atoms are lost (dissipated) from a BEC. Such dissipation leads to the decay of a BEC soliton. We demonstrate by a perturbation procedure that an alimentation of atoms from an external source to the BEC may compensate for the dissipation loss and lead to a dynamically-stabilized soliton. The result of the analytical perturbation method is in excellent agreement with mean-field numerics. It seems possible to obtain such a dynamically stabilized BEC soliton without dissipation in laboratory.

Osteologia craniana de Coraciiformes (Aves)

Dez famílias são tradicionalmente agrupadas na Ordem Coraciiformes, Alcedinidae (martins-pescadores), Momotidae (udus e juruvas), Todidae ( todies ), Meropidae (abelharucos), Coraciidae (rolieiros), Brachypteraciidae ( ground-rollers ), Leptosomidae ( cuckoo-rollers ), Phoeniculidae ( woodhoopoes ), Upupidae (poupas-comuns) e Bucerotidae (calaus), mas não há caracteres na morfologia externa que sejam comuns a todos os membros da ordem. Assim, este trabalho apresenta uma comparação da osteologia craniana das espécies de Coraciiformes com a finalidade de encontrar caracteres osteológicos que possam diagnosticar a ordem ou grupos de táxons de Coraciiformes, servindo ainda como uma fonte de dados para futuras análises filogenéticas. Como constatado por dados da morfologia externa, os caracteres da osteologia craniana ratificaram a diversidade morfológica existente entre os táxons da Ordem Coraciiformes, sendo difícil diagnosticá-la ou encontrar caracteres comuns a todos os seus membros. Apenas dois caracteres são comuns à ordem, tais como a presença da fossa lateroesfenóide e a ausência do processo suprameático, embora tais caracteres também sejam encontrados em outros grupos de aves. Homologias primárias foram encontradas, indicando similaridades entre diversas famílias, tais como: a zona flexória craniofacial é oclusa nos indiviíduos adultos de Coraciidae, Leptosomidae, Phoeniculidae, Upupidae e Bucerotidae; a fossa temporal tem desenvolvimento e profundidade intermediários em Momotidae, Meropidae, Coraciidae, Brachypteraciidae e Bucerotidae; o lacrimal está ausente em Momotidae, fundido com o ectetmóide nos adultos de Upupidae, Phoeniculidae e Bucerotidae, e presente e distinto em Alcedinidae, Todidae, Meropidae, Coraciidae, Brachypteraciidae e Leptosomidae; e o processo retroarticular da mandíbula é desenvolvido em Upupidae, Phoeniculidae e Bucerotidae.

Voltage responsivity of pyroelectric sensor

Composites polymer-ceramic using castor oil-based polyurethane (PU) as non-ferroelectric matrix and Lead Zirconate Titanate (PZT) as ceramic powder have been prepared at thin films form by spin coating. The samples are poled by appropriated electric field to show piezo and pyroelectric activity. The pyroelectric coefficient p(T) at 343 K is obtained to be equal 5.8 X 10(-5) C m(-2) K-1 for a composite with 32 vol.% of ceramic. The figure of merit of this composite is six times higher than of PZT ceramic. The voltage responsivity of the pyroelectric is reduced when the thickness of the sample increases. It was used modulated white light as radiation source to excite the sensor film. The electric signal of the sensor decreases with the light modulation frequency by 1/f. (C) 1999 Elsevier B.V. S.A. All rights reserved.

Dinâmica do potássio no solo e nutrição potássica da soja

Potassium deficiency in soybeans has spread iii São Paulo State, Brazil, as a consequence of soil K reserve depletion. Exchangeable and nonexchangeable K dynamics in soil were investigated in order to understand the reserve exaustion and its significance to soybean nutrition. Soybean was grown in 8 1 pots with five soils differing in K and clay contents, in presence or absence of K fertilization. Soil samples were taken at 20 days interval and soybean was harvest at R6. Exchangeable (H2SO4 0,05 N) and nonexchangeable K (boiling HNO3) were estimated in soil sample. Two of the soils were very poor in exchangeable K, and even so there was no response in dry matter due to K fertilization. In spite of some differences in K contents in some of the soybeans parts, generally K absorption was not affected by K fertilization, except in grains. Potassium acumulation in soybean plants were affected by soils, but the response was not closely related to exchangeable K in soil. The main K source to the plants was the HNO3 extrated K, showing that this form is not at all nonexchangeable. After the period of maximum plant demand there was a sharp increase in extractable K in soil showing a tendency to a natural equilibrium.

Infrared and far-infrared spectroscopy of (CH3OH)-C-13: TeraHertz laser lines and assignments

We use a (CO2)-C-13 laser as optical pumping source to search for new THz laser lines generated from (CH3OH)-C-13. Nineteen new THz laser lines (also identified as far-infrared, FIR) ranging from 42.3 mu m (7.1 THz) to 717.7 mu m (0.42 THz) are reported. They are characterized in wavelength, offset, relative polarization, relative intensity, and optimum working pressure. We have assigned eight laser lines to specific rotational energy levels in the excited state associated with the C-O stretching mode. (c) 2006 Elsevier B.V. All rights reserved.