Estudo do efeito da substituição de caulim por resíduo de caulim na fabricação de cerâmica de revestimento

Companies involved in kaolin mining and treatment represent an important area of industrial development in Brazil, significantly contribution to the worldwide production of such mineral. As a result, large volumes of kaolin residue are constantly generated and abandoned in the environment, negatively contributing to its preservation. In this scenario, the objective of the present study was to characterize the residue generated from kaolin mining as well as to assess its potential use as raw material for the production of ceramic tiles. Ceramic mixtures were prepared from raw materials characterized by X-ray fluorescence, X-ray diffraction, particle size analysis and thermal analysis. Three compositions were prepared using kaolin residue contents of 10%, 20% and 30%. Samples were uniaxially pressed, fired at 1200ºC and characterized aiming at establishing their mineralogical composition, water absorption, apparent porosity, specific mass, linear retraction and modulus of rupture. The results showed that the residue basically consisted of kaolinite and successfully replaced raw kaolin in the preparation of ceramic title formulations without significantly affecting the properties of the fired material

Efeito da adição de argila expandida e adições minerais na formulação de concretos estruturais leves autoadensáveis

The search for alternative materials with lower density, reduction in heat transfer and propagation of noise associated with the ease of handling and application in concrete structures, represents an enormous challenge in the formulation and knowledge of the performance of self-compacting lightweight concrete, which has technology little known nationally, and appears on the international scene as an innovative material and alternative to conventional concrete. Based on these, this study set out to study self-compacting lightweight concrete made with two distinct grades of expanded clay associated with the addition of plasticizing/superplasticizers additives and mineral additions of metakaolin and bagasse ash of sugar cane. There is also an object of study, evaluation of pozzolanic activity of mineral admixtures and their influence on the durability characteristics of concrete. The rheological, physical, mechanical and microstructural analysis in this study served as basis in the classification of concretes autoadensáveis, targeting the national technical requirements for their classification in the category autoadensável and lightweight structural. The inclusion of mineral admixtures (metakaolin and bagasse ash of sugar cane), partial replacement of cement, pozzolanic activity and demonstrated maintenance of mechanical properties through the filler effect, a reduction of up to 76% of the nitrogen gas permeability in blend with 20% bagasse ash. All concretes had rheology (cohesion and consistency) suitable for self-adensability as well as strength and density inherent structural lightweight concrete without presenting phenomena of segregation and exudation

Síntese e caracterização de ferritas de níquel dopadas com cobalto e efeito da substituição nas suas propriedades magnéticas

The ferrite composition Ni1 - xCoxFe2O4 (0 ≤ x ≤ 0.75) were obtained by the method of microwave assisted synthesis and had their structural and magnetic properties evaluated due to the effect of the substitution of Ni by Co. The compounds were prepared: according to the concept of chemical propellants and heated in the microwave oven with power 7000kw. The synthesized material was characterized by absorption spectroscopy in the infrared (FTIR), Xray diffraction (XRD) using the Rietveld refinement, specific surface area (BET) , scanning electron microscopy (SEM) with aid of energy dispersive analysis (EDS) and magnetic measurements (MAV). The results obtained from these techniques confirmed the feasibility of the method of synthesis employed to obtain the desired spinel structure, the ferrite, nickel ferrite as for nickel doped with cobalt. The results from XRD refinement ally showed the formation of secondary phases concerning stages α - Fe2O3, FeO, (FeCo)O e Ni0. On the other hand, there is an increase in crystallite size with the increase of cobalt in systems, resulting in an increased crystallinity. The results showed that the BET systems showed a reduction in specific surface area with the increase of cobalt and from the SEM, the formation of irregular porous blocks and that the concentration of cobalt decreased the agglomerative state of the system. The magnetic ferrites studied showed different characteristics according to the amount of dopant used, ranging from a very soft magnetic material (easy magnetization and demagnetization ) - for the system without cobalt - a magnetic material with a little stiffer behavior - for systems containing cobalt. The values of the coercive field increased with the increasing growth of cobalt, and the values of saturation magnetization and remanence increased up to x = 0,25 and then reduced. The different magnetic characteristics presented by the systems according to the amount of dopant used, allows the use of these materials as intermediates magnetic

Efeito da substituição do feno de Tifton 85 pelo caroço de algodão como fonte de fibra na dieta de bezerros

Para avaliar a substituição do feno Tifton 85 pelo caroço de algodão como fonte de fibra na dieta foram utilizados 24 bezerros da raça Holandesa, distribuídos em dois grupos. O grupo-feno recebeu feno e concentrado separados, fornecidos à vontade, e o grupo- algodão recebeu caroço de algodão incorporado ao concentrado (13,5%), à vontade. O consumo de alimentos, o peso, as alturas da cernelha e do íleo, as circunferências torácica e abdominal, a concentração de glicose sangüínea, as concentrações de acetato, propionato e butirato, o pH do fluido ruminal e os pesos dos compartimentos do estômago foram mensurados. O consumo de alimentos, o desenvolvimento ponderal dos animais, as concentrações de acetato, propionato e butirato, o pH do fluido ruminal, as concentrações de glicose sangüíneas e o peso dos compartimentos do estômago foram semelhantes entre os tratamentos (P>0,05). À necropsia, não foram observadas alterações sugestivas de intoxicação por gossipol. Concluiu-se que o caroço de algodão substituiu, sem prejuízos, o feno como fonte de fibra na dieta de bezerros.

Substituição do farelo de soja pela farinha de glúten de milho na alimentação de cabras leiteiras

Realizou-se um experimento com cabras Saanen, primíparas, pesando em média, 50 kg, alojadas em baias individuais de 3 m², objetivando avaliar a substituição da proteína do farelo de soja (FS) pela proteína da farinha de glúten de milho (FGM), na produção e composição do leite, consumo voluntário e níveis de uréia plasmática. O delineamento experimental foi o triplo quadrado latino 4x4, com quatro períodos de 21 dias, sendo 14 dias de adaptação à dieta e sete dias para colheita das amostras. As cabras foram alimentadas e ordenhadas pela manhã e tarde. Os níveis de substituição estudados foram 0, 10, 30 e 50% de FGM (base na proteína bruta). A substituição do farelo de soja pela farinha de glúten de milho não afetou o consumo (kg/dia e %PV) de matéria seca, proteína bruta e fibra em detergente ácido, mas houve efeito quadrático, para o consumo de fibra em detergente neutro (kg/dia e % PV). Houve efeito sobre os níveis de uréia plasmática (UP), que foram inferiores para os menores níveis de substituição, sendo os maiores valores de UP observados para o tratamento que possuía somente FS. A produção de leite decresceu linearmente com a inclusão da farinha de glúten de milho. Os níveis de substituição resultaram em decréscimos lineares na produção de gordura (kg/dia), no teor de gordura do leite (%) e no teor de sólidos totais. Houve efeito quadrático para produção de lactose (kg/dia), observando-se o menor valor estimado para o nível de substituição de 31,6%. Não foi observado efeito sobre a produção de proteína bruta no leite, cujo valor médio foi de 0,083 kg/dia. Os teores de proteina bruta, lactose e sólidos totais não sofreram efeito dos níveis de substituição, sendo os valores médios percentuais de 2,98; 4,35 e 11,51%, respectivamente.

Efeito da substituição da gema de ovo pela lecitina de soja na criopreservação de sêmen equino

Pós-graduação em Medicina Veterinária - FMVZ

Efeito do nível e da época de desfolha artificial sobre os componentes de produtividade de cultivares de algodoeiro

The periodic substitution of cotton cultivars for the farms can modify the levels of economic damages and control of pests, compromising the success in pest control. The objective of this work was to evaluate the effect of simulated defoliation levels in cotton cultivars actually used. The assay was carried out in experimental area of the Polo Apta Centro Norte, in Pindorama, Sao Paulo state. There were evaluated four defoliations levels (0%, 36.8%, 62.1% e 100%), done at a unique operation, in tree times (30, 60 and 90 days after plant emergence) and four cotton cultivars (IAC-25, DeltaOpal, Fibermax 966 and Fibermax 993). The defoliation was done with a scissor simulating the caterpillar damage. Evaluations included the number of open bolls, weight of one boll and 100 seeds, fiber percentage and productivity (kg ha(-1)). The defoliation negatively affected all components of agronomic traits, with the exception of percentage of fiber. The most damaging levels were 62.1 and 100% removal of the leaf blade. The period of higher susceptibility to defoliation occurs from 30 to 60 days after plant emergence.

Substituição parcial do farelo de soja pela farinha de carne e ossos em dietas para juvenis de tilápia-do-nilo

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

Efeito de diferentes antibióticos no processo de reparo em reimplante de dentes mantidos em leite: estudo em ratos

Pós-graduação em Odontologia - FOA

Fertilizantes e sistemas de irrigação: emissões de gases de efeito estufa no cultivo do milho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da substituição de plasma sanguíneo por levedura hidrolisada sobre rendimento e imunidade de leitões desmamados

O Experimento foi realizado com o objetivo de avaliar a substituição parcial e total de plasma bovino por levedura hidrolisada na dieta de leitões desmamados no período de 21 a 47 dias de idade. Foram utilizados 1600 leitões da linhagem PIC, distribuídos em blocos ao acaso, com quatro tratamentos. As dietas foram divididas em quatro fases (pré-inicial I 22 a 28 dias; pré-inicial II 29 a 35 dias; inicial I - 36 a 47 dias e inicial II 48 a 63 dias). A inclusão percentual, Plasma: Levedura, nas dietas foi: T1 (6:0; 4:0; 2:0 e 0:0); T2 (3: 4; 2: 3; 1: 2 e 0: 0); T3 (1,5: 6; 1: 4,5; 0,5: 3 e 0: 0) e T4 (0: 8; 0: 6; 0: 4 e 0: 0). Cada tratamento teve 10 repetições (cinco de machos e cinco de fêmeas) totalizando 40 unidades experimentais com 40 animais cada. As variáveis zootécnicas avaliadas durante o período experimental foram: consumo de ração, ganho de peso, e conversão alimentar. Foram tomadas amostras de sangue de 5 animais por tratamento no dia de início do experimento, e de 10 animais por tratamento 25 dias depois. Foram quantificadas a IgA e a IgG. Os dados obtidos foram submetidos a análise de variância ANOVA, utilizando-se o teste Tukey para comparação das médias ao nível de significância de 5% utilizando o pacote estatístico SAS. Não houve diferença estatística nas quantidades de Ig A e Ig G circulante, nem na variação destas imunoglobulinas no tempo, entre os tratamentos. Considerando a análise dos dados conclui-se que nas condições estudadas, a utilização da relação percentual de (1,5: 6; 1: 4,5; 0,5: 3 e 0: 0) de plasma: levedura hidrolisada resultou um maior consumo de ração e ganho de peso dos animais, em comparação às outras proporções, e consequentemente podendo trazer um maior lucro para o produtor

Efeito da adição de fibras da palma do licuri (syagrus coronata) no comportamento físico e mecânico de compósitos de matriz cimentícia

This research was motivated by the requirement of asbestos s replacement in building systems and the need to generate jobs and income in the country side of the state of Bahia, Brazil. The project aimed at using fibers from licuri leaves (syagrus coronata), an abundant palm in the region, to produce composites appropriate for the sustainable production of cement fibre reinforced products in small plants. The composites were produced in laboratory using Portland cement CP-II-F32, sand, water, licuri palm fiber contents of 1.0, 1.5 and 2.0% by weight of binder (two different fiber length) and metakaolin. The latter was chosen as an additional binder for its efficiency to reduce the alkalinity of cementitious matrixes therefore preventing the degradation of vegetable fibers. The characterization of the composite components was carried out by sieving and laser particle size analyses, thermal analysis, fluorescence and X-ray diffraction. The composites performance was evaluated by 3- point-bending tests, compressive strength, ultrasound module of elasticity, free and restrained shrinkage, water capillarity absorption and apparent specific gravity. It has been found that the addition of fibers increased the time to onset of cracking over 200.00% and a 25% reduction in cracks opening in the restrained shrinkage test. The capillary absorption reduced about 25% when compared to fiber-free composites. It was also observed with regard to flexural strength, compressive strength and specific gravity, that the addiction of fibers did not affect the composite performance presenting similar results for compounds with and without fibers. In general it can be stated that the reinforced composite fibers of palm licuri presents physical and mechanical characteristics which enable them to be used in the intended proposals of this research

Efeito da adição de cargas minerais leves na resistência mecânica de grautes para cimentação de poços offshore

The preparation of cement slurries for offshore well cementing involves mixing all solid components to be added to the mixing water on the platform. The aim of this work was to study the formulation of pre-prepared dry mixtures, or grouts, for offshore oilwell cementing. The addition of mineral fillers in the strength of lightweight grouts applied for depths down to 400 m under water depths of 500 m was investigated. Lightweight materials and fine aggregates were selected. For the choice of starting materials, a study of the pozzolanic activity of low-cost fillers such as porcelain tile residue, microsilica and diatomaceous earth was carried out by X-ray diffraction and mechanical strength tests. Hardened grouts containing porcelain tile residue and microsilica depicted high strength at early ages. Based on such preliminary investigation, a study of the mechanical strength of grouts with density 1.74 g/cm3 (14.5 lb/gal) cured initially at 27 °C was performed using cement, microsilica, porcelain tile residue and an anti-foaming agent. The results showed that the mixture containing 7% of porcelain tile residue and 7% of microsilica was the one with the highest compressive strength after curing for 24 hours. This composition was chosen to be studied and adapted for offshore conditions based on testes performed at 4 °C. The grout containing cement, 7% of porcelain tile residue, 7% of active silica and admixtures (CaCl2), anti-foaming and dispersant resulted satisfactory rheology and mechanical strength after curing for 24 hours of curing

Crowd Sourcing a New Paradigm for Interactome Driven Drug Target Identification in Mycobacterium tuberculosis

A decade since the availability of Mycobacterium tuberculosis (Mtb) genome sequence, no promising drug has seen the light of the day. This not only indicates the challenges in discovering new drugs but also suggests a gap in our current understanding of Mtb biology. We attempt to bridge this gap by carrying out extensive re-annotation and constructing a systems level protein interaction map of Mtb with an objective of finding novel drug target candidates. Towards this, we synergized crowd sourcing and social networking methods through an initiative `Connect to Decode' (C2D) to generate the first and largest manually curated interactome of Mtb termed `3interactome pathway' (IPW), encompassing a total of 1434 proteins connected through 2575 functional relationships. Interactions leading to gene regulation, signal transduction, metabolism, structural complex formation have been catalogued. In the process, we have functionally annotated 87% of the Mtb genome in context of gene products. We further combine IPW with STRING based network to report central proteins, which may be assessed as potential drug targets for development of drugs with least possible side effects. The fact that five of the 17 predicted drug targets are already experimentally validated either genetically or biochemically lends credence to our unique approach.

O papel da energia nas ações de mitigação

Descreve as alternativas energéticas que se colocam para mitigar boa parte das emissões de gases de efeito estufa (GEE) do planeta. Enfatiza o potencial para o uso mais eficiente da energia em todos os setores da economia e nas oportunidade de substituição de combustíveis fósseis por combustíveis renováveis. Ressalta a importância de mudança de hábitos de consumo para reduzir as emissões de GEE a níveis considerados seguros, de maneira a se estabilizarem as concentrações de gases na atmosfera em níveis suficientemente baixos.