Ação Sacietogênica de um inibidor de tripsina da semente de tamarindo (Tamarindus indica L.)

The seeds are excellent sources of proteinase inhibitors and have been highlighted owing to various applications. Among these applications are those in effect on food intake and weight gain that stand out because of the increasing number of obese individuals. This study evaluated the effects of trypsin inhibitor present in the seed of tamarind (Tamarindus indica L.) reduction in weight gain, biochemical and morphological alterations in Wistar rats. For this, we partially purified a trypsin inhibitor tamarind seed. This inhibitor, ITT2 at a concentration of 25 mg / kg body weight, over a period of 14 days was able to reduce food intake in rats (n = 6) by approximately 47%, causing a reduction in weight gain approximately 70% when compared with the control group. With the evaluation of the in vivo digestibility was demonstrated that the animals lost weight due to satiety, presented by the reduction of food intake, since there were significant differences between true digestibility for the control group (90.7%) and the group treated with inhibitor (89.88%). Additionally, we checked the deeds of ITT2 on biochemical parameters (glucose, triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, glutamic-pyruvic transaminase, glutamic oxaloacetic transaminase, gamma glutamyl transferase albumin, globulin, total protein and C-reactive protein) and these, when assessed in the study groups showed no statistically significant variations. We also evaluate the histology of some organs, liver, stomach, intestine, and pancreas, and showed no changes. And to evaluate the effect of trypsin inhibitor on food intake due to the satiety is regulated by cholecystokinin (CCK) were measured plasma levels, and it was observed that the levels of CCK in animals receiving ITT2 were significantly higher ( 20 + 1.22) than in animals receiving only solution with casein (10.14 + 2.9) or water (5.92 + 1.15). Thus, the results indicate that the effect caused ITT2 satiety, reducing food intake, which in turn caused a reduction in weight gain in animals without causing morphological and biochemical changes, this effect caused by the elevation of plasma levels CCK

Concreto celular polimérico: influência na adição de resíduo de poliéster insaturado termofixo

This work addresses the production of lightweight concrete building elements, such as plates, prefabricated slabs for pre-molded and panels of fencing, presenting a singular concrete: the Lightweight Concrete, with special properties such low density and good strength, by means of the joint use of industrial waste of thermosetting unsaturated polyesters and biodegradable foaming agent, named Polymeric Lightweight Concrete. This study covered various features of the materials used in the composition of the Polymeric Lightweight Concrete, using a planning of factorial design 23, aiming at studying of the strength, production, dosage processes, characterization of mechanical properties and microstructural analysis of the transition zone between the light artificial aggregate and the matrix of cement. The results of the mechanical strength tests were analyzed using a computational statistics tool (Statistica software) to understand the behavior and obtain the ideal quantity of each material used in the formula of the Polymeric Lightweight Concrete. The definition of the ideal formula has the purpose of obtaining a material with the lowest possible dry density and resistance to compression in accordance with NBR 12.646/92 (≥ 2.5 MPa after 28 days). In the microstructural characterization by scanning electron microscopy it was observed an influence of the materials in the process of cement hydration, showing good interaction between the wrinkled face of the residue of unsaturated polyesters thermosetting and putty and, consequently, the final strength. The attaining of an ideal formula, given the Brazilian standards, the experimental results obtained in the characterization and comparison of these results with conventional materials, confirmed that the developed Polymeric Lightweight Concrete is suitable for the production of building elements that are advantageous for construction

O efeito do tratamento da atapulgita no desenvolvimento de compósito com o polietileno reciclado

The study aimed at the treatment of attapulgite for the development and characterization of composite recycled low density polyethylene - PEBD_rec embedded with natural attapulgite - ATP_NAT, sifted - ATP_PN and attapulgite treated with sulfuric acid - ATP_TR in different compositions (1, 3 and 5%) and compared with the PEBD_rec. The atapulgitas, natural, screened and treated, were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), particle size analysis, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and determining the area specific surface (BET). The composites were characterized by thermogravimetry (TG), differential scanning calorimetry (DSC), Xray diffraction (XRD), torque rheometry, scanning electron microscopy (SEM) and traction. The composite PEBD_rec / ATP (natural, sieved and treated) were produced by mixing in the molten state in a single screw extruder matrix wire with subsequent reprocessing matrix tape. It was found that the screening of attapulgite not reduce the quantity of quartz and the acid treatment completely extracted dolomite aggregate impurities of the channels attapulgite, and increase their surface area. The addition of attapulgite in PEBD_rec acts as a catalyst, reducing the thermal stability of the polymer. The increased concentration of attapulgite, increases resistance and reduces the elongation at break and modulus of elasticity of the composite PEBD_rec / attapulgite

Efeito da incorporação de diatomita na estabilidade e permeabilidade de compósitos cimentíceos espumados aplicados a poços de petróleo

Lightweight oilwell cement slurries have been recently studied as a mean to improve zonal isolation and sheath-porous formation adherence. Foamed slurries consisting of Portland cement and air-entraining admixtures have become an interesting option for this application. The loss in hydrostatic pressure as a consequence of cement hydration results in the expansion of the air bubbles entrapped in the cement matrix, thus improving the sheath-porous formation contact. Consequently, slurries are able to better retain their water to complete the hydration process. The main objective of the present study was to evaluate the effect of the addition of an air-entraining admixture on the density, stability and permeability of composite slurries containing Portland cement and diatomite as light mineral load. Successful formulations are potential cementing materials for low fracture gradient oilwells. The experimental procedures used for slurry preparation and characterization were based on the American Petroleum Institute and ABNT guidelines Slurries containing a pre-established concentration of the air-entraining admixture and different contents of diatomite were prepared aiming at final densities of 13 to 15 lb/gal. The results revealed that the reduction of 15 to 25% of the density of the slurries did not significantly affect their strength. The addition of both diatomite and the air-entraining admixture increased the viscosity of the slurry providing better air-bubble retention in the volume of the slurry. Stable slurries depicted bottom to top density variation of less than 1.0 lb/gal and length reduction of the stability sample of 5.86 mm. Finally, permeability coefficient values between 0.617 and 0.406 mD were obtained. Therefore, lightweight oilwell cement slurries depicting a satisfactory set of physicochemical and mechanical properties can be formulated using a combination of diatomite and air-entraining admixtures for low fracture gradient oilwells

Comportamento magnético de compósitos de matriz polimérica com adição de ferritas

Polymer matrix composites offer advantages for many applications due their combination of properties, which includes low density, high specific strength and modulus of elasticity and corrosion resistance. However, the application of non-destructive techniques using magnetic sensors for the evaluation these materials is not possible since the materials are non-magnetizable. Ferrites are materials with excellent magnetic properties, chemical stability and corrosion resistance. Due to these properties, these materials are promising for the development of polymer composites with magnetic properties. In this work, glass fiber / epoxy circular plates were produced with 10 wt% of cobalt or barium ferrite particles. The cobalt ferrite was synthesized by the Pechini method. The commercial barium ferrite was subjected to a milling process to study the effect of particle size on the magnetic properties of the material. The characterization of the ferrites was carried out by x-ray diffraction (XRD), field emission gun scanning electron microscopy (FEG-SEM) and vibrating sample magnetometry (VSM). Circular notches of 1, 5 and 10 mm diameter were introduced in the composite plates using a drill bit for the non-destructive evaluation by the technique of magnetic flux leakage (MFL). The results indicated that the magnetic signals measured in plates with barium ferrite without milling and cobalt ferrite showed good correlation with the presence of notches. The milling process for 12 h and 20 h did not contribute to improve the identification of smaller size notches (1 mm). However, the smaller particle size produced smoother magnetic curves, with fewer discontinuities and improved signal-to-noise ratio. In summary, the results suggest that the proposed approach has great potential for the detection of damage in polymer composites structures

O papel da lisofosfatidilcolina na ativação do inflamassoma NLRP3 e sua relação com a formação de células gordurosas

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Molecular, 2016.

Estudo comparativo de pás para aerogeradores de grande porte fabricadas em materiais compósitos reforçadas com fibra de carbono ou fibra de vidro

The research and development of wind turbine blades are essential to keep pace with worldwide growth in the renewable energy sector. Although currently blades are typically produced using glass fiber reinforced composite materials, the tendency for larger size blades, particularly for offshore applications, has increased the interest on carbon fiber reinforced composites because of the potential for increased stiffness and weight reduction. In this study a model of blade designed for large generators (5 MW) was studied on a small scale. A numerical simulation was performed to determine the aerodynamic loading using a Computational Fluid Dynamics (CFD) software. Two blades were then designed and manufactured using epoxy matrix composites: one reinforced with glass fibers and the other with carbon fibers. For the structural calculations, maximum stress failure criterion was adopted. The blades were manufactured by Vacuum Assisted Resin Transfer Molding (VARTM), typical for this type of component. A weight comparison of the two blades was performed and the weight of the carbon fiber blade was approximately 45% of the weight of the fiberglass reinforced blade. Static bending tests were carried out on the blades for various percentages of the design load and deflections measurements were compared with the values obtained from finite element simulations. A good agreement was observed between the measured and calculated deflections. In summary, the results of this study confirm that the low density combined with high mechanical properties of carbon fibers are particularly attractive for the production of large size wind turbine blades

Influência da vermiculita expandida na formulação de pastas leves para evitar a migração de gás em cimentação de poços petrolíferos

The gas migration during the cementing of wells is one of the main problems of oil wells engineering. Its occurrence can cause severe problems since shortly to loss of control of the well after cementation. Recently, 20/04/2010 In an accident of major proportions in the Gulf of Mexico, among other factors, faulty cementing operation provided the gas migration, causing the accident, in which 11 people died and 17 were injured occurred. Besides the serious consequences that can be caused by gas migration, remediation of the problem, which is made by injecting cement in damaged areas, usually involves additional costs and is not always effective. Therefore, preventing gas migration to be preferred. Some methods are used to prevent the migration of the pressurized gas as the annular space, application of pressure pulses, reducing the height of the cement column compressible cement pastes of low permeability, pastes and to control free filtered water, and binders of thixotropic cement expandable and flexible. Thus, the cement pastes used to prevent gas migration must meet the maximum these methods. Thus, this study aimed to formulate a cement paste to prevent gas migration, using the expanded vermiculite, and evaluate the behavior of the folder trials necessary for use in oil wells. Free water content, rheological properties, compressive strength, loss of liquid phase sedimentation of solids, specific weight, thickening time and gas migration: The following tests were performed. The results show that meets the specifications paste formulated for use in oil wells and the use of expanded vermiculite contribute to the absorption of free water, thixotropy and low density. The absorption of free water is proven to result in zero percentage test free water content, thixotropy is observed with the high value of the initial gel strength (Gi) in testing rheological properties and low density is proven in test weight specific

Formulação e caracterização de pastas espumadas por incorporação de ar e estabilizantes minerais

Cementing operations may occur at various stages of the life cycle of an oil well since its construction until its definitive abandonment. There are some situations in which the interest zones are depleted or have low fracture pressure. In such cases, the adoption of lowdensity cement slurries is an efficient solution. To this end, there are basically three ways to reduce the density of cement slurries: using microspheres, water extending additives or foamed cement. The objective of this study is to formulate, to study and to characterize lowdensity foamed cement, using an air entrainment surfactant with vermiculite or diatomite as water extenders and stabilizers. The methodology consists on preparation and evaluation of the slurries under the American Petroleum Institute (API) and the Brazilian Association of Technical Standards (ABNT) guidelines. Based on calculated densities between 13 and 15 ppg (1.559 and 1.799 g/cm3), the slurries were prepared with fixed surfactant concentration, varying the concentrations of vermiculite and diatomite and were compared with the base slurries. The results of plastic viscosity, yield point and gel strength and the compressive strength for 24 h showed that the slurries presented suitable rheology and mechanical strength for cementing operations in oil wells, and had their densities reduced between 8.40 and 11.89 ppg (1.007 and 1.426 g/cm3). The conclusion is that is possible, under atmospheric conditions, to obtain light weighted foamed cement slurries with satisfactory rheological and mechanical properties by means of air entrainment and mineral additions with extenders and stabilizers effects. The slurries have great potential for cementing operations; applicability in deep wells, in low fracture gradient formations and in depleted zones and bring cost savings by reducing the cementing consumption

Desenvolvimento de pastas leves utilizando incorporadores de ar para aplicação em poços de petróleo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Nova técnica para obtenção de fraturas com altíssima condutividade em poços de petróleo

Increase hydrocarbons production is the main goal of the oilwell industry worldwide. Hydraulic fracturing is often applied to achieve this goal due to a combination of attractive aspects including easiness and low operational costs associated with fast and highly economical response. Conventional fracturing usually involves high-flowing high-pressure pumping of a viscous fluid responsible for opening the fracture in the hydrocarbon producing rock. The thickness of the fracture should be enough to assure the penetration of the particles of a solid proppant into the rock. The proppant is driven into the target formation by a carrier fluid. After pumping, all fluids are filtered through the faces of the fracture and penetrate the rock. The proppant remains in the fracture holding it open and assuring high hydraulic conductivity. The present study proposes a different approach for hydraulic fracturing. Fractures with infinity conductivity are formed and used to further improve the production of highly permeable formations as well as to produce long fractures in naturally fractured formations. Naturally open fractures with infinite conductivity are usually encountered. They can be observed in rock outcrops and core plugs, or noticed by the total loss of circulation during drilling (even with low density fluids), image profiles, pumping tests (Mini-Frac and Mini Fall Off), and injection tests below fracturing pressure, whose flow is higher than expected for radial Darcian ones. Naturally occurring fractures are kept open by randomly shaped and placed supporting points, able to hold the faces of the fracture separate even under typical closing pressures. The approach presented herein generates infinite conductivity canal held open by artificially created parallel supporting areas positioned both horizontally and vertically. The size of these areas is designed to hold the permeable zones open supported by the impermeable areas. The England & Green equation was used to theoretically prove that the fracture can be held open by such artificially created set of horizontal parallel supporting areas. To assess the benefits of fractures characterized by infinite conductivity, an overall comparison with finite conductivity fractures was carried out using a series of parameters including fracture pressure loss and dimensionless conductivity as a function of flow production, FOI folds of increase, flow production and cumulative production as a function of time, and finally plots of net present value and productivity index

O falar de Marvão

Nesta dissertação, é estudado o Falar de Marvão, um concelho de raia, do Alto Alentejo, com baixa densidade demográfica, população muito envelhecida e uma taxa de analfabetismo acima da média nacional e regional. O presente estudo é composto por cinco capítulos. Nos dois primeiros, são apresentados os estudos dialectológicos realizados no distrito de Portalegre e é caracterizado o concelho de Marvão. O estudo do falar desenrola-se ao longo dos três capítulos principais, dedicados aos aspectos fonético-fonológicos e morfo-sintácticos, bem como ao léxico relacionado com o Homem. O Falar de Marvão está integrado nos dialectos portugueses centro-meridionais, mais especificamente na variedade da Beira Baixa e Alto Alentejo. Assim, apresenta a maior parte das características identificadas pelos linguistas do século XX sobre esta região dialectal, demarcando-se, contudo, por algumas particularidades que o distinguem dos falares dos concelhos circundantes, essencialmente ao nível de alguns aspectos fonético-fonológicos e do léxico. /ABSTRACT: ln this dissertation is presented a study on The Marvão 's Dialect, a bordering district from Alto Alentejo, with a low demographic density, very old population and a rate of illiteracy above the national and regional average. This study is composed by five chapters. ln the two first chapters, are presented the dialectological studies, which took place in the district of Portalegre, and there is also characterized the district of Marvão. The study of the dialect is developed along the three main chapters, which are dedicated to the phonetic, phonologic, morphologic and syntactic aspects, as well as the lexicon related to the human being. The Marvão 's dialect is integrated in the centre-meridional portuguese dialects, specifically in the Beira Baixa and Alto Alentejo’s diversity, presenting the main characteristics identified in this dialectical region by the linguists of the XX century. However, it distinguishes itself by some particularities, which differentiate it from the dialects spoken in the surrounding districts, mainly on the level of some phonetic and phonologic aspects and the lexicon.

TRANSIÇÃO RURAL OU REGRESSO AO PASSADO? REFLEXÕES EM TORNO DOS ATORES DA 2.ª RURALIDADE

Ao longo da segunda metade do século XX, os territórios rurais do sul da Europa sofreram à semelhança da generalidade dos territórios do ocidente profundas transformações. No caso de Portugal, a transformação mais notória diz respeito ao processo de desagregação entre o conceito de rural e agricultura, provocando profundas mutações nas dinâmicas sociodemográficas e económicas dos territórios. De uma forma generalizada os territórios rurais ganharam novas atribuições e surgem como espaços de consumo e pós-produtivistas, onde se desenvolvem múltiplas atividades produtivas, relacionadas com um novo modelo ecossocioeconómico, sendo objeto de novas procuras e interesses urbanos. No entanto, e apesar do quadro recessivo, de crescimento do desemprego e da emigração, assistimos nos últimos anos de assistência económica e financeira da Troika, ao ressurgimento da agricultura com investimentos agrícolas, florestais e agroalimentares no âmbito dos programas de desenvolvimento rural, acompanhados de um discurso idílico por parte dos políticos e meios de comunicação de um suposto regresso à terra. O objetivo deste trabalho é aprofundar o conhecimento em torno dos processos territoriais em curso, através da caraterização dos atores da 2.ª ruralidade que protagonizam novas dinâmicas e tendências em alguns territórios rurais de baixa densidade, bem como as ligações e inter-relações entre o urbano e o rural. A metodologia utilizada baseia-se em fontes documentais e estatísticas e em inquéritos por questionário aos neo-rurais das Aldeias Históricas de Portugal. A principal fonte de dados resultou da recolha de dados a 27 neo-rurais. Estes questionários para além da definição do perfil dos neo-rurais, também permitiram identificar os motivos de deslocação para o meio rural, as atividades económicas e um conjunto de medidas/iniciativas para minimizar os efeitos da baixa densidade territorial.

Cartografia geoquímica da ilha de Santiago com uma densidade de amostragem média/baixa

A ilha de Santiago é a maior do arquipélago de Cabo Verde, apresenta uma área de 991 km2, com um comprimento e largura máximos de 54,9 km e 29 km, respectivamente, e 1392 m de maior altitude. As condições climáticas e a erosão são alguns dos problemas naturais do arquipélago de Cabo Verde. Além disso, a intervenção humana no ambiente superficial revela-se muitas vezes inadequada e com forte impacto. A construção em solos com aptidão agrícola ou florestal, as actividades industriais, a deposição de materiais sólidos ou líquidos de forma inadequada, as práticas agrícolas incorrectas e intensivas, o uso abusivo de pesticidas e fertilizantes, a rega com água contaminada, a sobreexploração de aquíferos que levam muitas vezes à salinização, etc. têm enorme impacto em termos de contaminação de solos, águas superficiais e subterrâneas nas áreas envolventes. Por conseguinte, o conhecimento da variabilidade geoquímica natural é fundamental para a resolução de questões de índole económica, ambiental e de ordenamento do território, médica, e jurídica. A necessidade de construir uma base de dados de geoquímica georeferenciada que caracterize o ambiente superficial da ilha de Santiago foi a principal motivação para a realização deste estudo. Realizou-se um levantamento geoquímico de 337 amostras de sedimentos de corrente e 249 amostras de solos na ilha de Santiago, tendo sido seguidas as recomendações do Projecto Internacional IGCP 259 não só na fase de amostragem, mas também nas fases seguintes de preparação, análise, tratamento dos dados e elaboração de mapas. Determinaram-se os teores, na fracção < 2 mm, para 36 elementos – 9 elementos maiores (Al, Ca, Fe, K, Mg, Mn, Na, P, Ti) e 27 elementos vestigiais (Ag, As, Au, B, Ba, Bi, Cd, Co, Cr, Cu, Ga, Hg, La, Mo, Ni, Pb, S, Sb, Sc, Se, Sr, Th, Tl, U, V, W, Zn). Efectuou-se ainda a análise textural e estudou-se a composição mineralógica de cerca de 25% das amostras. Analisaram-se, também, 103 amostras de rochas, colhidas nas várias formações da ilha de Santiago, tendo sido determinados os teores de K2O, Na2O, Fe2O3(T), MnO, Sc, Cr, Co, Zn, Ga, As, Br, Rb, Zr, Sb, Cs, Ba, Hf, Ta, W, Th e U e REE, a fim de se fazer uma comparação com os teores destes elementos encontrados nos solos e sedimentos de corrente, averiguando se a sua variação é ou não essencialmente condicionada pela geoquímica da rocha-mãe. Os padrões geoquímicos obtidos através dos mapas de distribuição espacial foram correlacionados com a natureza da rocha mãe, o tipo de solo, e ainda com algumas fontes de contaminação. A interpretação dos resultados foi realizada não só pela observação dos mapas geoquímicos, mas também após análise estatística dos conjuntos de dados obtidos, e apoiada em informação diversa disponível. A utilização da Análise de Componentes Principais permitiu distinguir associações entre elementos químicos, quer de origem geogénica quer antropogénica. Foram ainda elaborados mapas de distribuição espacial de vários índices multielementares de importância ambiental, como o Índice de Acidificação Al/(Ca+Mg+K), Índice de Combi, Índice de Avaliação de Risco Ambiental e Índices de Enriquecimento/Contaminação para vários grupos de elementos considerados como “primary pollutant metals”.

Espectrofotometria de longo caminho óptico em espectrofotô metro de duplo-feixe convencional: uma alternativa simples para investigações de amostras com densidade óptica muito baixa

We describe the design and tests of a set-up mounted in a conventional double beam spectrophotometer, which allows the determination of optical density of samples confined in a long liquid core waveguide (LCW) capillary. Very long optical path length can be achieved with capillary cell, allowing measurements of samples with very low optical densities. The device uses a custom optical concentrator optically coupled to LCW (TEFLON® AF). Optical density measurements, carried out using a LCW of ̃ 45 cm, were in accordance with the Beer-Lambert Law. Thus, it was possible to analyze quantitatively samples at concentrations 45 fold lower than that regularly used in Spectrophotometric measurements.