Homens e mulheres nos assentamentos: violência, recusa e resistência na construção de um novo modo de vida

O artigo trata da construção da experiência de assentamentos rurais no bojo dos conflitos entre as imposições do projeto estatal e a tentativa de construção de um novo modo de vida por parte dos trabalhadores assentados. Essas tensões explicitam e dissimulam violências, presentes também no cotidiano dos assentados, em suas relações de gênero, parentesco e produção. Verificam-se, sempre tendo como base a perspectiva das mulheres, episódios de recusa e resistência ao que lhes é imposto.

Uma leitura de 26 poetas hoje / A reading of 26 poetas hoje

Este trabalho procura identificar selecionadas produções poéticas da antologia 26 Poetas Hoje as faces da resistência indicada por Alfredo Bosi no ensaio “Poesia Resistência”. Do “grito de alarme” pessoal de poetas pertencentes a gerações diferentes, emerge uma poesia espontânea, autêntica e, sobretudo, resistente, como produto da renovação da expressão poética, impregnado de afetividades e de intimismo e que incorporou o coloquial e os recursos da grande poesia brasileira desde 22. This reading presents a sample from this anthology and tries to identify in it the faces of resistance indicated by Alfredo Bosi in his essay: “ Poesia Resistência”. In the several manners the poets of different generations chose for their personal cry of alert we find a poetry wich is spontaneous, authentic and, above all, “resistent”. This is due mainly to the renewal of the poetical expression, impregnated with affective ness and intimism, which included colloquial language and devices used by all great Brazilian poetry since the modernism of 1922.

Atributos físicos e químicos do solo sob cultivos de outono-inverno em sistema de semeadura direta

Pós-graduação em Agronomia (Agricultura) - FCA

Impact strength and abrasion resistance of high strength concrete with rice husk ash and rubber tires

The paper discusses the application of High Strength Concrete (HSC) technology for concrete production with the incorporation of Rice Husk Ash (RHA) residues by replacing a bulk of the material caking and rubber tires with partial aggregate volume, assessing their influence on the mechanical properties and durability. For concrete with RHA and rubber, it was possible to reduce the brittleness by increasing the energy absorbing capacity. With respect to abrasion, the RHA and rubber concretes showed lower mass loss than the concrete without residues, indicating that this material is attractive to be used in paving. It is thus hoped that these residues may represent a technological and ecological alternative for the production of concrete in construction works.

Contribuições da teoria das restrições para gestão da mudança

Pós-graduação em Engenharia de Produção - FEB

Análise cinemática e dinâmica para conversão de um VW saveiro em veículo elétrico

This work aims to kinematic and dynamic analysis of a VW Saveiro in order to estimate the power requested to the engine with the imposed movement conditions. Thus, the study will be the basis to the specification of the electric engine, on the conversion of the internal combustion vehicle into electric one. First of all, a literature review was done in order to understand the state of the art for this issue and come up with the technical features of the vehicle in question. The next step is the identification and calculation of all forces acting on the prototype in motion, from 0 to 120 km/h, in intervals of 10 km/h, under the defined conditions of path and time. Then, were determined the values of the torque and rotation of the components from the transmission system, as well as the engine power, for each speed range. The results show the most influential forces on the resistence of the movement in each speed range, and the behavior of the torque curve is verified. Finally, it was also analyzed the implementation of pinwheels on the frontal area of the vehicle, in order to convert wind energy into electrical energy to supply the lighting subsystem of the vehicle and the proposal was validated. Limiting the maximum speed of the vehicle to 90 km/h, it was finally concluded that the power of the electric engine should be 40 HP

Caracterização de cerâmicas a base de nitreto de silício para aplicações estruturais

The need for development of new materials is a natural process in the companies’ technological point of view, seeking improvements in materials and processes. Specifically, among the materials, ceramic exhibit valuable properties, especially the covalent ceramics which have excellent properties for applications which requires the abrasion resistance, hardness, high temperatures, resistence, etc. being a material that has applications in several areas. Most studies are related to improvement of properties, specially fracture toughness that allows the expansion of its application. Among the most promising ceramic materials are silicon nitride (Si3N4) which has excellent properties. The goal of this work was the development and caracterization of Si3N4-based ceramics, doped with yttrium oxide (Y2O3), rar earth concentrate (CTR2O3) and cerium oxide (CeO2) in the same proportion for the evaluation of properties. The powders' mixtures were homogenized, dried and compressed under pressure uniaxial and isostatic. Sintering was carried out in 1850 ⁰C under pressure of 0,1MPa N2 for 1 h with a heating rate of 25 ⁰C / min and cooling in the furnace inertia. The characterizations were performed using Archimedes principle to relative density, weight loss by measuring before and after sintering, phase analysis by X-ray diffraction, microstructure by scanning electron microscope (SEM), hardness and fracture toughness by the method Vickers indentation. The results obtained showed relative density of 97-98%, Vickers hardness 17 to 19 GPa, fracture toughness 5.6 to 6.8 MPa.m1/2, with phases varying from α-SiAlON and β-Si3N4 depending the types of additives used. The results are promising for tribological applications and can be defined according to the types of additives to be used

Efeito da atividade física na sensibilidade à insulina e no sinal insulínico em ratos com doença periodontal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Associação de antibióticos e terapia fotodinâmica antimicrobiana para o controle de Acinetobacter baumannii

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo estrutural, morfológico, elétrico e óptico de cristais de a-Ag2WO4 dopados com Mo6+ via co-precipitação assistida por PVP

Pós-graduação em Química - IQ

Caracterização genética e distribuição espacial dos isolados de Mycobacterium leprae em região de baixa prevalência no Brasil

Pós-graduação em Doenças Tropicais - FMB

A influência da temperatura de pré-aquecimento e tecimento na microestrutura e propriedades mecânicas na soldagem MIG/MAG robotizada de aços SAE 8620 com ABNT LN28

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pequena produção de cachaça no interior paulista: a informalidade em questão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pequena produção de cachaça no interior paulista: a informalidade em questão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cluster-derived Gold/Iron catalysts for environmental applications

During the last years we assisted to an exponential growth of scientific discoveries for catalysis by gold and many applications have been found for Au-based catalysts. In the literature there are several studies concerning the use of gold-based catalysts for environmental applications and good results are reported for the catalytic combustion of different volatile organic compounds (VOCs). Recently it has also been established that gold-based catalysts are potentially capable of being effectively employed in fuel cells in order to remove CO traces by preferential CO oxidation in H2-rich streams. Bi-metallic catalysts have attracted increasing attention because of their markedly different properties from either of the costituent metals, and above all their enhanced catalytic activity, selectivity and stability. In the literature there are several studies demostrating the beneficial effect due to the addition of an iron component to gold supported catalysts in terms of enhanced activity, selectivity, resistence to deactivation and prolonged lifetime of the catalyst. In this work we tried to develop a methodology for the preparation of iron stabilized gold nanoparticles with controlled size and composition, particularly in terms of obtaining an intimate contact between different phases, since it is well known that the catalytic behaviour of multi-component supported catalysts is strongly influenced by the size of the metal particles and by their reciprocal interaction. Ligand stabilized metal clusters, with nanometric dimensions, are possible precursors for the preparation of catalytically active nanoparticles with controlled dimensions and compositions. Among these, metal carbonyl clusters are quite attractive, since they can be prepared with several different sizes and compositions and, moreover, they are decomposed under very mild conditions. A novel preparation method was developed during this thesis for the preparation of iron and gold/iron supported catalysts using bi-metallic carbonyl clusters as precursors of highly dispersed nanoparticles over TiO2 and CeO2, which are widely considered two of the most suitable supports for gold nanoparticles. Au/FeOx catalysts were prepared by employing the bi-metallic carbonyl cluster salts [NEt4]4[Au4Fe4(CO)16] (Fe/Au=1) and [NEt4][AuFe4(CO)16] (Fe/Au=4), and for comparison FeOx samples were prepared by employing the homometallic [NEt4][HFe3(CO)11] cluster. These clusters were prepared by Prof. Longoni research group (Department of Physical and Inorganic Chemistry- University of Bologna). Particular attention was dedicated to the optimization of a suitable thermal treatment in order to achieve, apart from a good Au and Fe metal dispersion, also the formation of appropriate species with good catalytic properties. A deep IR study was carried out in order to understand the physical interaction between clusters and different supports and detect the occurrence of chemical reactions between them at any stage of the preparation. The characterization by BET, XRD, TEM, H2-TPR, ICP-AES and XPS was performed in order to investigate the catalysts properties, whit particular attention to the interaction between Au and Fe and its influence on the catalytic activity. This novel preparation method resulted in small gold metallic nanoparticles surrounded by highly dispersed iron oxide species, essentially in an amorphous phase, on both TiO2 and CeO2. The results presented in this thesis confirmed that FeOx species can stabilize small Au particles, since keeping costant the gold content but introducing a higher iron amount a higher metal dispersion was achieved. Partial encapsulation of gold atoms by iron species was observed since the Au/Fe surface ratio was found much lower than bulk ratio and a strong interaction between gold and oxide species, both of iron oxide and supports, was achieved. The prepared catalysts were tested in the total oxidation of VOCs, using toluene and methanol as probe molecules for aromatics and alchols, respectively, and in the PROX reaction. Different performances were observed on titania and ceria catalysts, on both toluene and methanol combustion. Toluene combustion on titania catalyst was found to be enhanced increasing iron loading while a moderate effect on FeOx-Ti activity was achieved by Au addition. In this case toluene combustion was improved due to a higher oxygen mobility depending on enhanced oxygen activation by FeOx and Au/FeOx dispersed on titania. On the contrary ceria activity was strongly decreased in the presence of FeOx, while the introduction of gold was found to moderate the detrimental effect of iron species. In fact, excellent ceria performances are due to its ability to adsorb toluene and O2. Since toluene activation is the determining factor for its oxidation, the partial coverage of ceria sites, responsible of toluene adsorption, by FeOx species finely dispersed on the surface resulted in worse efficiency in toluene combustion. Better results were obtained for both ceria and titania catalysts on methanol total oxidation. In this case, the performances achieved on differently supported catalysts indicate that the oxygen mobility is the determining factor in this reaction. The introduction of gold on both TiO2 and CeO2 catalysts, lead to a higher oxygen mobility due to the weakening of both Fe-O and Ce-O bonds and consequently to enhanced methanol combustion. The catalytic activity was found to strongly depend on oxygen mobility and followed the same trend observed for catalysts reducibility. Regarding CO PROX reaction, it was observed that Au/FeOx titania catalysts are less active than ceria ones, due to the lower reducibility of titania compared to ceria. In fact the availability of lattice oxygen involved in PROX reaction is much higher in the latter catalysts. However, the CO PROX performances observed for ceria catalysts are not really high compared to data reported in literature, probably due to the very low Au/Fe surface ratio achieved with this preparation method. CO preferential oxidation was found to strongly depend on Au particle size but also on surface oxygen reducibility, depending on the different oxide species which can be formed using different thermal treatment conditions or varying the iron loading over the support.