Viabilidade econômica da utilização do biogás produzido em granja suínícola para geração de energia elétrica

A produção de biogás por meio de biodigestão anaeróbia representa um avanço para equacionar o problema dos dejetos produzidos pela suinocultura e disponibilidade de energia no meio rural. Este trabalho teve como objetivo estimar a viabilidade econômica de um sistema biointegrado para geração de eletricidade a partir do aproveitamento de dejetos de suínos. Os dados para este estudo foram coletados em uma agroindústria, onde são realizadas diversas atividades agrícolas; entretanto, a suinocultura foi selecionada para o processo de análise de biodigestão anaeróbia, pelo fato de gerar uma grande quantidade de dejetos, com dificuldade de disposição no meio ambiente, configurando um estudo de caso. O biodigestor analisado é um modelo tubular contínuo, com calha de água em alvenaria e com uma manta plástica como gasômetro, onde são depositados diariamente os dejetos de 2.300 suínos em fase de terminação. O investimento inicial para implantação foi estimado em R$ 51.537,17, e os custos anuais do sistema foram de R$ 5.708,20 com manutenção, R$ 4.390,40 com depreciação e R$ 1.366,77 com juros. Concluiu-se que o sistema de produção de biogás é viável do ponto de vista econômico, se o consumo de energia elétrica for de 35 kWh por dia, em média, onde o valor presente líquido (VLP) é de R$ 9.494,90, e a taxa interna de retorno (TIR) é de 9,34% ao ano.

Cobre e zinco no material percolado e no solo com a aplicação de água residuaria de suinocultura em solo cultivado com soja

O objetivo deste trabalho foi avaliar possíveis efeitos da aplicação de taxas de água residuária de suinocultura (ARS), quanto às concentrações de cobre e zinco, tanto no solo quanto na água percolada de lisímetros de drenagem, durante o ciclo da cultura da soja. O experimento foi conduzido em ambiente protegido, onde havia 24 lisímetros de drenagem. Semeou-se soja cultivar CD 202, e foram aplicadas ARS nas seguintes dosagens: 0; 100; 200 e 300 m³ ha-1 no ciclo, combinadas com duas adubações na semeadura (com e sem adição da adubação recomendada na semeadura), em três repetições por tratamento. Foram feitas seis coletas do material percolado durante o ciclo da cultura e realizadas determinações de cobre e zinco. No solo, foram feitas três coletas em cada parcela experimental, para a determinação do pH, da matéria orgânica, da capacidade de troca catiônica, do cobre e do zinco. O delineamento foi em blocos casualizados, num esquema fatorial de 4 x 2. Observou-se que o cobre no solo não apresentou diferenças significativas com a aplicação de ARS e adubação, enquanto as concentrações de zinco no solo foram influenciadas pelas taxas aplicadas de ARS. As transferências de cobre e de zinco por percolação foram pouco expressivas.

Caracterização de cerâmicas porosas de alumina reforçada com zircônia produzidas pelo método da réplica

Porous ceramics have many applications: thermal insulation, catalytic support, materials to fire protection, filters, and others. There are many techniques to production of ceramic filters. One technique to obtain ceramic filters is the replication method. This method consists in the impregnation of polymeric foam with ceramic slurry followed by a heating treatment that will burn out the organic elements and sintering of the material, resulting of a replication of the original foam. To perform their functions ceramic filters must satisfy mechanical requirements and permeability parameters (darcian k1 and no-darcian k2). The permeability and the strength of the ceramic material are dependent of the pore size and pore distribution. To the use at high temperatures the evaluation of mechanical properties in these temperatures is necessary. In this work the mechanical behavior of two commercial porous ceramics (10 and 40 poros per inch) was studied these materials were submitted to compression and four-point flexure test (room temperature, at 1000 °C, after thermal shock). Density and porosity measurements, permeability tests and microstructural analysis by scanning electronic microscopy (SEM) were realized. The Results showed that the decrease of mechanical strength of these materials, when submitted to thermal shock, occur for propagation of new cracks from cracks pre-existing and the permeability depends of the pore size

Efeito de adições poliméricas na aderência de pastas de cimento a tubos metálicos após ciclagem térmica

Thermal recovery methods, especially steam injection, have been used to produce heavy oils. However, these methods imply that the metallic casing-cement sheath interface is submitted to thermal cycling. As a consequence, cracking may develop due to the thermal expansion mismatch of such materials, which allows the flow of oil and gas through the cement sheath, with environmental and economical consequences. It is therefore important to anticipate interfacial discontinuities that may arise upon Thermal recovery. The present study reports a simple alternative method to measure the shear strength of casing-sheath interfaces using pushthrough geometry, applied to polymer-containing hardened cement slurries. Polyurethane and recycled tire rubber were added to Portland-bases slurries to improve the fracture energy of intrinsically brittle cement. Samples consisting of metallic casing sections surrounded by hardened polymer-cement composites were prepared and mechanically tested. The effect of thermal cycles was investigated to simulate temperature conditions encountered in steam injection recovery. The results showed that the addition of polyurethane significantly improved the shear strength of the casing-sheath interface. The strength values obtained adding 10% BWOC of polyurethane to a Portland-base slurry more than doubled with respect to that of polyurethane-free slurries. Therefore, the use of polyurethane significantly contributes to reduce the damage caused by thermal cycling to cement sheath, improving the safety conditions of oil wells and the recovery of heavy oils

Análise do comportamento mecânico de espumas cerâmicas a base de alumina obtidas pelo método da réplica

Ceramics with porous cellular structure, called ceramic foams, have a potential use in several applications, such as: thermal insulation, catalyst supports, filters, and others. Among these techniques to obtain porous ceramics the replication method is an important process. This method consists of impregnation of a sponge (usually polymer) with ceramic slurry, followed by a heat treatment, which will happen the decomposition of organic material and sintering the ceramic material, resulting in a ceramic structure which is a replica of impregnated sponge. Knowledge of the mechanical properties of these ceramics is important for these materials can be used commercially. Gibson and Ashby developed a mathematical model to describe the mechanical behavior of cellular solids. This model wasn´t for describing the ceramics behavior produced by the replica method, because it doesn´t consider the defects from this type of processing. In this study were researched mechanical behavior of porous alumina ceramics obtained by the replica method and proposed modifications to the model of Gibson and Ashby to accommodate this material. The polymer sponge used in processing was characterized by thermogravimetric analysis and scanning electron microscopy. The materials obtained after sintering were characterized by mechanical strength tests on 4-point bending and compression, density and porosity and by scanning electron microscopy. From these results it was evaluated the mechanical strength behavior compared to Gibson and Ashby model for solid cellular structure and was proposed a correction of this model through a factor related to struts integrity degree, which consider fissures present in the structure of these materials besides defects geometry within the struts

Implementação de um modelo computacional para estudo do processo Fischer-Tropsch em reator de leito de lama

This work aims at the implementation and adaptation of a computational model for the study of the Fischer-Tropsch reaction in a slurry bed reactor from synthesis gas (CO+H2) for the selective production of hydrocarbons (CnHm), with emphasis on evaluation of the influence of operating conditions on the distribution of products formed during the reaction.The present model takes into account effects of rigorous phase equilibrium in a reactive flash drum, a detailed kinetic model able of predicting the formation of each chemical species of the reaction system, as well as control loops of the process variables for pressure and level of slurry phase. As a result, a system of Differential Algebraic Equations was solved using the computational code DASSL (Petzold, 1982). The consistent initialization for the problem was based on phase equilibrium formed by the existing components in the reactor. In addition, the index of the system was reduced to 1 by the introduction of control laws that govern the output of the reactor products. The results were compared qualitatively with experimental data collected in the Fischer-Tropsch Synthesis plant installed at Laboratório de Processamento de Gás - CTGÁS-ER-Natal/RN

Desenvolvimento de sistemas de pastas leves para aplicação em cimentação de poços petrolíferos com baixo gradiente de fratura

All around the world, naturally occurring hydrocarbon deposits, consisting of oil and gas contained within rocks called reservoir rocks , generally sandstone or carbonate exists. These deposits are in varying conditions of pressure and depth from a few hundred to several thousand meters. In general, shallow reservoirs have greater tendency to fracture, since they have low fracture gradient, ie fractures are formed even with relatively low hydrostatic columns of fluid. These low fracture gradient areas are particularly common in onshore areas, like the Rio Grande do Norte basin. During a well drilling, one of the most favorable phases for the occurrence of fractures is during cementing, since the cement slurry used can have greater densities than the maximum allowed by the rock structure. Furthermore, in areas which are already naturally fractured, the use of regular cement slurries causes fluid loss into the formation, which may give rise to failures cementations and formation damages. Commercially, there are alternatives to the development of lightweight cement slurries, but these fail either because of their enormous cost, or because the cement properties were not good enough for most general applications, being restricted to each transaction for which the cement paste was made, or both reasons. In this work a statistical design was made to determine the influence of three variables, defined as the calcium chloride concentration, vermiculite concentration and nanosilica concentration in the various properties of the cement. The use of vermiculite, a low density ore present in large amounts in northeastern Brazil, as extensor for cementing slurries, enabled the production of stable cements, with high water/cement ratio, excellent rheological properties and low densities, which were set at 12.5 lb / gal, despite the fact that lower densities could be achieved. It is also seen that the calcium chloride is very useful as gelling and thickening agent, and their use in combination with nanosilica has a great effect on gel strength of the cement. Hydrothermal Stability studies showed that the pastes were stable in these conditions, and mechanical resistance tests showed values of the order of up to 10 MPa

Síntese de Fischer-Tropsch sobre perovskitas LayCu0,4Fe0,6O3

The current natural gas production of 52 Mm3d-1 and the large projects for its expansion has been setting new boundaries for the Brazilian industry of oil and gas. So far, one of the biggest challenges regards to the logistics for gas transportation from offshore fields. Therefore, the transformation of natural gas into gasoline, diesel and/or olefins via Fischer-Tropsch synthesis would be an alternative to this matter. In this work, the production of hydrocarbons by Fischer-Tropsch synthesis in a slurry reactor was investigated and a perovskite-type catalyst (LayCu0,4Fe0,6O3 ± d) was used with y varying from 0 to 1 on a molar basis. In addition, Nb2O5 support was also applied in order to observe the selectivity of the produced hydrocarbons by the Fischer-Tropsch process. It is shown that the hydrogen conversion was influenced by the support as well as the different phases of the samples. The kinetic results for the CO2 production suffered great influence with the introduction of the Nb2O5 support throughout the series of samples studied. The catalysts allowed obtaining welldefined cuts of hydrocarbons in the range of C1-C6 and C17-C28, and these results were clearly influenced by the support and the lanthanum content. The higher olefin/paraffin ratio obtained was 1.8 when using a non-supported perovskite with y equal to 0.8. This would indicate the suitability of using this material for the production of olefins

Study of Monoethanolamine Nitrate Content Reduction in Explosive Slurries

The reduction of the fuel content of a monoethanolamine nitrate (MEAN) fueled explosive slurry was investigated. The work was performed in three phases. The first one involved the MEAN content reduction in a reference slurry from its initial value of 36 down to 24% by weight, the balance being filled with ammonium nitrate, the least expensive item in the slurry composition. This proved to be successful, leading to an overall cost reduction of 17%, while keeping the overall performance quite satisfactory. The second phase consisted in trying to bring the MEAN content down from 24 to 17%. Although this led to further cost reduction, the formulations, obtained by substituting part of the MEAN content by ammonium nitrate/fuel oil (ANFO), produced unsatisfactory results regarding ignition and densities. In the third phase, the Design of Experiments Technique was used to find formulations displaying not only lower cost, but also acceptable overall performance. This led to a raw material cost reduction ranging from 23 to 26% relative to the initial reference slurry formulation.

Evaluation of strip rolling directly from the semi-solid state

defect metal alloy strip when thixorolling directly from the semi-solid state. To facilitate the study lead/tin alloys were chosen for their relatively low operating temperature. The objective is to extrapolate these findings to the higher temperature aluminium, alloys. Three alloys (70%Pb30%Sn, 60%Pb-40%Sn, 50%Pb-50%wtSn) were used particularly to study the influence of the solidification interval. The equipment consists of a two roll mill arranged as an upper and lower roller, where both rollers are driven at a controlled speed. The lower roller is fed with semi solid alloy through a ceramic nozzle attached to the lower end of a cooling slope. Several types of nozzle and their position at the roller were tested. This produced different solidifications and consequently different finished strip. The alloys were first cast and then poured onto the cooling slope through a tundish in order to create a continuous laminar flow of slurry and uniformity of metal strip quality. The pouring was tested at different positions along the slope. The cooling slope was coated with colloidal graphite to promote a smooth slurry flow and avoid the problem of adherence and premature solidification. The metallic slurry not only cools along the slope but is also initially super-cooled to a mush by the lower roller whilst at room temperatures, thus enabling thixorolling. It was also found that the nozzle position could be adjusted to enable the upper roller to also contribute to the solidification of the metallic slurry. However the rollers and the cooling slope naturally heat up. Temperature distribution in these zones was analysed by means of three thermocouples positioned along the cooling slope and a fourth in the base of the semi solid pool within the nozzle. The objective being to design an optimum pouring and cooling system. The formed strip was cooled down to room temperature with a shower of water. Microstructures of the thixorolling process were analysed. The differences in solidification conditions resulted in differing qualities of finished strip and corresponding defect types, all of which are a serious quality issue for the rolled product.

Desenvolvimento de misturas ternárias para remoção de reboco de fluido de perfuração sintético

The construction of wells is one of the most important activities of the oil industry. The drilling process is the set of activities and operations to design, program and perform the opening thereof. During this process, the cuttings are removed by the drilling fluid, or mud, and carted to the surface. This fluid is injected into the drill string and returns to the surface through the annular space between the well walls and the drill string. After the descent of the column casing, the annular space between the casing string and the walls of the borehole is filled with cement so as to secure the spine and prevent any migration of fluids between the various permeable zones traversed by the well behind of the coating. To ensure the good quality of the cementation scrubbers are used mattresses which are pumped ahead of the cement slurry so as to avoid contamination of the drilling fluid paste, or vice versa, and assist in the removal of plaster, formed by drilling fluid of the borehole walls, thus enabling a better cement bond to the well. Within this context, this work aims to evaluate the efficiency of mattresses scrubbers, the basis of ionic and nonionic surfactants, on the removal of nonaqueous drilling fluid, based on n-paraffin in oil wells, and the compatibility between the Mattress relations washer / drilling fluid bed scrubber / cement paste mattress washer / cement slurry / drilling fluid and the drilling fluid / cement slurry using laboratory tests rheology, thickening time and compressive strength. Also technique was performed X-ray diffraction (XRD) for a more detailed analysis of these mixtures with hydrated cement paste. In compatibility tests the conditions of temperature and pressure used in the same laboratory procedure simulating the conditions of oil wells, the well is considered the depth of 800 m. The results showed that the compositions of the mattress washer nonionic, KMS obtained a 100% efficient in removing the non-aqueous drilling fluid, and the best formulation showed good results with respect to compliance testing

Pharmacokinetics of intraosseous and central venous drug delivery during cardiopulmonary resuscitation

We compared the pharmacokinetics of intraosseous (IO) drug delivery via tibia or sternum, with central venous (CV) drug delivery during cardiopulmonary resuscitation (CPR).Methods: CPR of anesthetized KCl arrest swine was initiated 8 min post arrest. Evans blue and indocyanine green, each were simultaneously injected as a bolus with adrenaline through IO sternal and tibial needles, respectively, n = 7. In second group (n = 6) simultaneous IO sternal and IV central venous (CV) injections were made.Results: Peak arterial blood concentrations were achieved faster for sternal IO vs. tibial IO administration (53 +/- 11 s vs. 107 +/- 27 s, p = 0.03). Tibial IO dose delivered was 65% of sternal administration (p = 0.003). Time to peak blood concentration was similar for sternal IO and CV administration (97 +/- 17 s vs. 70 +/- 12 s, respectively; p = 0.17) with total dose delivered of sternal being 86% of the dose delivered via CV (p = 0.22).Conclusions: IO drug administrations via either the sternum or tibia were effective during CPR in anesthetized swine. However, IO drug administration via the sternum was significantly faster and delivered a larger dose. (C) 2011 Elsevier B.V. All rights reserved.

Microsporum nanum. quarto relato de infecção humana no Brasil

Comunica-se o quarto relato de infecção humana por Microsporum nanum (M. nanun) no Brasil. Trata-se de criança de 9 meses de idade, apresentando há um mês lesões cutâneas dorsais compatíveis com tinea corporis. As lesões foram frustas, regredindo espontaneamente após um mês. A investigação epidemiológica na área de origem do caso índice identificou suínos infectados por Microsporum nanum, sugerindo ser esta a fonte de infecção.

Fraturas vertebrais em grandes animais: estudo retrospectivo de 39 casos (1987-2002)

Realizou-se estudo retrospectivo (1987-2002) dos aspectos clínicos das fraturas vertebrais em eqüinos, bovinos, ovinos, caprinos e suínos atendidos no hospital veterinário da FMVZ-Unesp de Botucatu. Todos os casos tiveram confirmação radiográfica ou post-mortem. Segundo a espécie, a ordem de acometimento foi: bovina, eqüina, ovina, caprina e suína. As lesões ocorreram desde os 12 dias de idade até os 10 anos, com maior freqüência até os 12 meses. O segmento torácico foi o mais comprometido seguido dos segmentos lombar, cervical e sacral. As fraturas vertebrais devem fazer parte da lista de diagnósticos diferenciais de animais em decúbito, independente da espécie, sexo ou idade.

Identification, characterization and expression analysis of hepcidin gene in sheep

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)