Regeneração natural de mata ciliar em ecossistema de floresta estacional semidecidual: chuva de sementes e banco de sementes do solo

The knowledge of the dynamics of soil seed bank and seed rain is fundamental to understand the forest succession process, as well as for its conservation and restoration. This paper aimed at studying the role of the soil seed bank and seed rain in the dynamics of a riparian tropical seasonal forest fragment located on the hinterland of São Paulo State. The seed rain was studied by 30 litter traps installed at 50 cm from the floor, with an area of 50 cm x 50 cm. Between November of 2008 and October of 2009, 11364 seeds of 82 species belonging to 33 different families were collected. The deposition density of seeds was 126.27 individuals.m². With the data obtained from this research, the two seasons couldn’t be differed from each other hence 2009 was an atypical year considering the precipitation, which was constantly elevated. For the soil seed bank, fifty superficial soil samples will be taken at the end of both the rainy and dry seasons. The germination method was applied for the data analysis. It was observed a predominance of herbaceous habit species, with an average of 71% of the germinations in both seasons. The Sφrensen similarity index between the seasons was low (0,27). The density and species diversity were higher after the rainy season, unlike other published researches

Estudo teórico da contribuição à dose de partículas secundárias geradas por Prótons de energias entre 100 e 200 MeV num Phantom de osso cortical

In proton therapy, the deposition of secondary particles energy originated by nuclear inelastic process (n, 2H, 3H, 3He and α) has a contribution in the total dose that deserves to be discussed. In calculations of plans implemented for routine treatment, the paid dose is calculated whereas the proton loses energy by ionization and or coulomb excitement. The contribution of inelastic processes associated with nuclear reactions is not considered. There are only estimates for pure materials or simple composition (water, for example), because of the difficulty of processing targets consisting of different materials. For this project, we use the Monte Carlo method employing the code MCNPX v2.50 (Monte Carlo N-Particle eXtended) to present results of the contribution to the total dose of secondary particles. In this work, it was implemented a cylindrical phantom composed by cortical bone, for proton beams between 100 and 200 MeV. With the results obtained, it was possible to generate graphics to analyze: the dose deposition relation with and without nuclear interaction, the multiplicity and percentage of deposited dose for each secondary particle and a radial dispersion of neutrons in the material

Equações de taxa aplicadas na modelagem de dispositivos fotodetectores baseados em poços quânticos

In this work, it is presented a novel method for calculating some intrinsic parameters such as capture mean time, thermic emission mean time, capture probability and noise gain on quantum well infrared photodetectors. Such devices are built by depositing layers of semiconductors of different energy gap, forming quantum wells. The present method uses rate equations to describe the occupation of discrete states of the quantum wells, that together with noise gain equations given in literature, are solved self consistently. The input data of the method is experimental measurement of dark current (current measured with no relevant incident photon) versus applied bias. In order to validate this approach, the values obtained were compared with results from literature

Estudos de degradação de filmes de polietileno

A produção de lixo pela humanidade é inevitável, porém, o destino dos residuos sólidos e seu acondicionamento inadequado têm trazido graves problemas ambientais. Dentre os resíduos sólidos, os plásticos merecem destaque, pois cresceram significativamente em uso e descarte, totalizando 20% do volume mundial de lixo. Isto decorre de algumas das propriedades destes materiais, como durabilidade, resistência, leveza e baixo custo de produção. Nas grandes cidades brasileiras, 7% do lixo produzido correspondem a produtos de plástico em filme, geralmente usado em aplicações de curta duração, como o polietileno. Este material persiste no ambiente por décadas, sendo, portanto, resistente à degradação. Diversos destinos podem ser tomados pelo resíduo de polietileno descartado, como a deposição em lixões e aterros sanitários, incineração, reciclagem e biodegradação. A biodegradação pode ser definida como a degradação catalisada por atividade biológica, levando, no final do processo, à mineralização e/ou formação de biomassa. Na natureza, a destruição destes materiais se dá, na verdade, por meio da “degradação ambiental”, na qual atuam sinergeticamente a biodegradação, a fotooxidação, a termo-oxidação e a hidrólise. Neste sentido, desde os anos 1970, diferentes formulações foram propostas para otimizar a susceptibilidade do PE à degradação ambiental. Sabe-se que o PE está sujeito a sofrer mudanças quando exposto à luz ultravioleta e/ou ao calor, e que estas modificações podem alterar a resposta dos microrganismos no processo de biodegradação. Desta forma, este estudo analisou as modificações ocasionadas por tratamentos com luz ultravioleta, calor e exposição ao sol, bem como a resposta da microbiota natural do solo a estes tratamentos, através de análises de espectroscopia... (Resumo completo, clicar acesso eletrônico abaixo)

Microartefatos e processo de esculturação de vertentes: um estudo de caso do sítio arqueológico Lagoa do Camargo - Rio Claro-SP

This work discusses the analysis of microartifacts as a means to study the process of sculpturing of slopes actants of slopes actants of sculpturing in the archaeological site Lagoa do Camargo. Microartifacts have specific characteristics of transportation and deposition, that helps identifying shaping and sculpturing processes of slopes. The methogology used for analysis of microartifacts is based in Dunnel and Stein's theory (1989) that defines microartifacts as artifacts with reduced size - between 2mm and 0,25mm. According to the authors, an artifact is any object that presents attributes consequent of human activity, in other words, artificial. Also is used the protocol of Vance (1989), that proposed the analysis only the fraction between 0,5mm and 0,250 mm. For disclosure and preservation of archaeological patrimony in the city of Rio Claro, is intended development activities with schools of municipal education system, abour the subject Patrimonial Education, with the methodology adopted by the Institute for National Artistic and Historical Patrimony (IPHAN). Demonstrate and emphasize the importance of cultural patrimony within the local community provides the (re) cognition of these areas as conservation areas, which can be incorporated by this population as areas of collective interest

Manifestações oculares na leishmaniose

The Canine Visceral Leishmaniasis is a chronic disease of endemic character, caused by Leishmania Chagasi in Americas. The inoculation of the promastigote form in the individual triggers a local and widespread immune reaction with formation of inflammatory infiltrates and deposition of immune complexes in tissues. Initial clinical symptoms of the disease are: weight reduction, hepatomegaly, splenomegaly and, according to the disease chronicity, signs such as alopecia, erythema, onychogryphosis, arthropathies, renal diseases, pyoderma, seborrheic dermatitis, muscle atrophy and Ocular diseases. Ocular diseases are often reported and are result of the direct parasitism or immune-mediated mechanisms caused by the disease. The Leishmania spp have greater affinity for the anterior segment, so that anterior uveitis is one of the most frequently diagnosed injuries. Blepharitis diffuse and Keratoconjunctivitis also appear as important ocular changes. In histological section, inflammatory infiltrates and macrophages with amastigote form are observed in all ocular tissues, with the exception of the retina and optical nerve. In the clinical analysis and disease diagnosis, should be considered the differential diagnosis, such as Ehrlichiosis and systemic hypertension, because these may cause some ocular manifestations similar to those observed in leishmaniasis

Confecção e caracterização de filmes finos de boro para a medida da taxa de reação 10B(N, a)7LI na terapia por captura de nêutrons pelo boro

The Boron Neutron Capture Therapy (BNCT), based on the 10B(n,α)7Li reaction, represents a promising modality for the treatment of cancers that are resistents to conventional treatments. So, it is necessary to find drugs (boron compounds) with high selectivity for each type of cancer, the neutrons source should be well characterized and the rate of 10B(n,α)7Li reaction should be measured with great accuracy as possible. This study aimed to develop a method for manufacturing thin films of boron, for measure the 10B(n,α)7Li reaction, and analyze the uniformity of the films. Five thin films of boron were manufactured with three different concentrations of boric acid, heated to transform the acid in boron, irradiated with thermic neutrons coupled to CR-39 detectors, in BNCT line at the reactor IEA-R1 IPEN/CNEN, São Paulo. After the irradiation, the detectors were chemically attacked with NaOH to reveal the tracks. The methodology presented is effective because it resulted in deposition of boron as thin film enabling the quantitative analysis of 10B(n,α)7Li reaction. The analysis of the uniformity of density of the induced tracks in CR-39 shows that, in most of the films, there is no uniformity in surface distribution of boron, but when the film is divided, we obtain some uniform sectors

Análise da viabilidade de simulações com feixes de prótons de 100, 150, 200 e 250 MeV em alvos heterogêneos

In the recent years, the use of proton beams in radiotherapy has been an outstanding progress (SMITH, 2006). Up to now, computed tomography (CT) is a prerequisite for treatment planning in this kind of therapy because it provides the electron density distribution required for calculation of dose and the interval of doses. However, the use of CT images for proton treatment planning ignores fundamental differences in physical interaction processes between photons and protons and is, therefore, potentially inaccurate (SADROZINSKI, 2004). Proton CT (pCT) can in principle directly measure the density distribution needed in a patient for the dose distribution (SCHULTE, et al, 2004). One important problem that should be solved is the implementation of image reconstruction algorithms. In this sense, it is necessary to know how the presence of materials with different density and composition interfere in the energy deposition by ionization and coulomb excitation, during its trajectory. The study was conducted in two stages, was used in both the program SRIM (The Stopping and Range of Ions in Matter) to perform simulations of the interaction of proton beams with pencil beam type. In the first step we used the energies in the range of 100-250 MeV (ZIEGLER, 1999). The targets were set to 50 mm in length for the beam of 100 MeV, due to its interaction with the target, and short-range, and 70 mm for 150, 200 and 250 MeV The target was composed of liquid water and a layer of 6 mm cortical bone (ICRP). It were made 9 simulations varying the position of the heterogeneity of 5 mm. In the second step the energy of 250 MeV was taken out from the simulations, due to its greater energy and less interaction. The targets were diminished to 50 mm thick to standardize the simulations. The layer of bone was divided into two equal parts and both were put in the ends of the target... (Complete abstract click electronic access below)

Estudo teórico da contribuição a dose de partículas secundárias geradas por prótons de energias entre 100-200 MeV num phantom de osso compacto

The contribution of the total dose due to deposition of secondary energy particles caused by nuclear inelastic processes (n, 2H, 3H, 3He and  ) in proton therapy is an opened problem and in discussion. In the calculations of plans implemented for routine treatment, the paid dose is calculated whereas that the proton loses energy by ionization and or coulomb excitement. The contribution of inelastic processes associated with nuclear reactions is not considered, mainly due to the difficulty of processing targets consisting of various materials. In this sense, there are only estimates for pure materials or simple composition (water, for example).This work presents the results of simulations by the Monte Carlo method employing the code MCNPX v2.50 (Monte Carlo N-Particle eXtended) of the contribution to the total dose of secondary particles. The study was implemented in a cylindrical phantom composed by compact bone, for monochromatic beams of protons between 100 and 200 MeV with pencil beam form

Aplicação de produtos fitossanitários na cultura dos citros utilizando pulverizador envolvente

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Estudo de tensões residuais em juntas soldadas utilizando o método dos elementos finitos

Pós-graduação em Engenharia Mecânica - FEG

Desenvolvimento de recobrimento submicrométrico de óxido de nióbio para aplicação em tubulações de prospecção de petróleo

Pós-graduação em Engenharia Mecânica - FEG

Interação composto de lodo de esgoto e cinzas de biomassa no desenvolvimento inicial de eucalipto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Identificação e caracterização de fungos melanizados com potencial de degradação de tolueno

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diodo planar orgânico Schottky: construção e caracterização

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)