Apresenta-se aqui a caracterização do filito e a avaliação da sua aplicação como carga mineral na produção de materiais plásticos. Amostras de jazidas em lavra no município de Itapeva, sudoeste do Estado de São Paulo, foram preparadas em laboratório, através de secagem e peneiramento, e analisadas física e quimicamente, sendo comparadas com outros minérios utilizados comumente como cargas minerais. Uma dessas amostras, após sua preparação, foi aplicada como carga na produção de peças plásticas no Centro Técnico de Serviços CTS da empresa Braskem S.A., a partir de pastas formadas com PVC e plastificantes, conhecidas como plastisóis. O filito foi incorporado em varias formulações de compostos utilizados para produção de bolas plásticas comuns. Os resultados, em termos de resistência mecânica, foram comparados com os de compostos contendo carbonato de cálcio natural, moído, em malha inferior a 44 m. O carbonato de cálcio natural, ou calcita, constitui a carga mais tradicionalmente utilizada nesse setor industrial. Os testes realizados indicaram que o filito confere ao material polimérico produzido, composto de polímeros, aditivos e cargas, propriedades desejáveis de resistência mecânica e acabamento, algumas propriedades resultando melhores que as obtidas com o uso da calcita para determinadas proporções e formulações. Os resultados obtidos permitem concluir que o filito beneficiado comporta-se similarmente a minerais industriais tradicionais e pode vir a ser empregado na indústria de plásticos dito reforçados na geração de produtos diversos tais como bolas de parque, cabeças de bonecas, tapetes, tubos plásticos flexíveis e painéis de veículos, entre outros segmentos do setor. / This paper presents the characterization of the White-phyllite and an evaluation of its application as filler in the production of plastic materials. Phyllite samples with origin in ore body located in the district of Itapeva, southwest area of Sao Paulo State, they were beneficiated, prepared in laboratory through granulometric separation and drying and applied in the production of reinforced thermoplastic (Plastisol) in laboratories of the Braskem S. A. located in São Paulo city. The accomplished tests indicated that the beneficiated phyllite checks to the material plastic produced desirable properties of mechanical resistance and finish. The use of the phyllite it was compared with the calcite in the production of the plastics materials in several composition and proportions, showing in some compositions strips better than obtained results them with the calcite, traditional filler used for those products. The obtained results allow to conclude that the phyllite, properly beneficiated, is similar to traditional industrial minerals and it can benefit the industry of plastics reinforced in the production, among others, of balls, doll heads, rubber rugs, flexible plastic tubes, panels of vehicles.

Nenhuma / Microanalysis performed in situ by electron microprobe technique (EPMA) enabled systematic and detailed studies of chemical dating of monazite from marine placers in Buena region, northern coast of Rio de Janeiro State. High spatial resolution BSE imaging allowed recognizing complex internal zoning and selecting spots for microanalysis. Zoning patterns commonly concentric and complex types for every heterogeneous grains studied presented remarkably similar composition. Heterogeneous patterns probably are associated with metamorphic recristalization (peak of metamorphism) and/or dissolution-reprecipitation (retrograde metamorphism) processes which transported Th contents between different domains of heterogeneous grains. Homogeneous grains are scarce and could be specific cross-cutting section of domains from heterogeneous grains. Following elements have been identifyied by EPMA: Ce, La, Pr, Nd, Sm, Gd, Dy, Y, Th, U, Pb, Si, Ca, Fe and Mn and revealed a typical Monazite-(Ce) composition. Th contents for concentric heterogeneous grains range from ≈ 4 to 7 wt% and from ≈ 2 to 10 wt% for complex heterogeneous grains are related to magmatic monazites undergone to metamorphic processes. Light rare earth elements (including Gd) demonstrate strong depletion related to Dy and Y in every analysed grain of monazite. (La/Nd)N ratio for both heterogeneous (≈ 1.5 a 2.7) and homogeneous grains (≈ 1.7 a 3.2) is similar, as well as (La/Y)N ratio shows an average value approximately ~ 200 for all grains. U-Th-Pb contents yielded chemical ages in the range since 592 to 530Ma consistent with metamorphism peak during 590 and 550Ma sin-collisional event of the Araçuaí/Ribeira Belt related to Mantiqueira Tectonic Province. Isotopic age data obtained by LA-ICP-MS (580 to 530Ma) are equivalent to chemical ages and validate the laborious methodology for U-Th-Pb ages by EPMA developed and applied in this study. Supported on ages and igneous and metamorphic growing patterns showed by heterogeneous grains, the suggested source rocks for monazite from Buena could possibly be related with lithologies of G2 and G3 suite, crystalized and submitted to metamorphic processes from high-amphibolite to granulite facies. / As microanálises executadas in situ pela microssonda eletrônica, segundo a metodologia desenvolvida neste trabalho, tornaram possível um estudo sistemático da química mineral e datação U-Th-Pb da monazita proveniente de pláceres marinhos na região de Buena-RJ, litoral norte fluminense. Imagens obtidas por elétrons retroespalhados com alta resolução espacial permitiram reconhecimento de complexo zoneamento interno e posicionamento dos pontos para execução das microanálises. Os padrões de zoneamento comumente encontrados em todos os grãos heterogêneos estudados correspondem aos tipos concêntricos e complexos que apresentam composições muito semelhantes. As heterogeneidades de grãos provavelmente estão associadas a processos de recristalização durante metamorfismo progressivo (pico do metamorfismo) e/ou dissolução-reprecipitação (retrometamorfismo), os quais remanejam os teores de Th entre os diferentes domínios dos grãos. Escassos grãos homogêneos de monazita parecem tratar de uma seção de corte em domínios específicos de grãos heterogêneos. Os seguintes elementos foram identificados por EPMA: Ce, La, Pr, Nd, Sm, Gd, Dy, Y, Th, U, Pb, Si, Ca, Fe e Mn e apontam para composição de monazita-(Ce). Os teores em Th para grãos heterogêneos concêntricos no intervalo entre ≈ 4 e 7 % (peso) e para grãos heterogêneos complexos entre ≈ 2 a 10 % (peso) são semelhantes aos valores de monazita magmática submetidas a processos metamórficos. A distribuição de elementos terras-raras em todos os grãos apresenta um forte empobrecimento dos elementos mais leves (incluindo Gd), em relação a Dy e Y. A razão (La/Nd) N para os grãos heterogêneos (≈ 1.5 a 2.7) e homogêneos (≈ 1.7 a 3.2) é equivalente. O valor médio em torno de 200 na razão (La/Y) N é similar nos grãos homogêneos e heterogêneos. A partir de teores de U-Th-Pb foram determinadas idades químicas no intervalo entre 530 e 592Ma relacionadas com o pico do metamorfismo regional da Província Mantiqueira, durante a fase sin-colisional da Faixa Araçuaí/Ribeira, onde idades variam entre 590 e 550Ma. Idades isotópicas realizadas por LA-ICP-MS forneceram idades (530 e 580Ma) compatíveis com as idades químicas. Esses resultados comprovam a validade da laboriosa rotina analítica para obtenção das idade U-Th-Pb em monazita, utilizando a microssonda eletrônica, que foi desenvolvida e aplicada durante este trabalho. Com base nas idades e nos padrões ígneos e metamórficos de desenvolvimento dos grãos heterogêneos, as prováveis rochas-fonte desses grãos de monazita seriam as litologias das suítes G2 e G3 que foram cristalizadas e, concomitantemente, submetidas a processos de metamorfismo que variaram de fácies anfibolito alto a granulito.

O cobre está associado ao metabolismo de lipídios, sendo bastante importante na redução do colesterol, e à estabilidade oxidativa da carne, por fazer parte de algumas enzimas antioxidantes. Atributos esses que tornam cada vez mais interessante a pesquisa do uso do mineral em várias espécies, com vista a melhorar a qualidade de vida dos consumidores, uma vez que se pode reduzir o risco de doenças cardiovasculares e câncer, assim como dos fornecedores de carne pelo possível aumento da vida de prateleira e das características organolépticas do produto. Desse modo, o objetivo deste estudo foi determinar o efeito da suplementação com dois níveis de sulfato de cobre e cobre metionina sobre o metabolismo de lipídios e colesterol e estabilidade oxidativa lipídica da carne em cordeiros Merino x Texel. Para o efeito, um experimento foi conduzindo na FZEA, USP de Pirassununga utilizando 40 cordeiros Merino x Texel, que foram distribuídos aleatoriamente em 5 tratamentos, totalizando 8 animais em cada. Os animais foram alojados em gaiolas individualizadas para estudo de metabolismo e o experimento teve a duração de 120 dias. Os tratamentos usados foram: controle, sem adição; suplementação com 10 ou 30 mg de Cu/Kg de MS na forma de sulfato de Cobre; suplementação com 10 ou 30 mg de Cu/Kg de MS na forma de cobre metionina. Foram feitas biópsias do fígado dos animais no tempo zero para análise de cobre e colhidas amostras de sangue para dosagem sérica de Cu. Nos dias 0, 28 e 56 foram colhidas amostras de sague para dosagem de colesterol total, HDL e triglicerídeos. Ao final do experimento, os animais foram abatidos para colheita de amostras de fígado para determinação dos teores de Cu; dosagem das enzimas glutationa reduzida (GSH), glutationa oxidada (GSSH), atividade das enzimas antioxidantes, superóxido dismutase (SOD) e glutationa peroxidase (GP-x) e determinação dos níveis das substâncias reativas ao ácido tiobarbitúrico (TBARS). No momento da desossa foi medida a espessura da gordura subcutânea entre a 12ª e 13ª costela. No mesmo momento, foram colhidas amostras do músculo longissimus para dosagem de colesterol total, análise de perfil de ácidos graxos e TBARS. O músculo longissimus esquerdo foi retirado e congelado a vácuo por 12 meses, após os quais amostras foram colhidas e expostas no expositor refrigerado a 4°C para estudo da estabilidade oxidativa lipídica que foi acompanhada pelos valores de TBARS nos dias 0, 3 e 6. A suplementação com cobre proporcionou maior acúmulo de Cu no fígado (P<0,05), porém, a concentração do elemento no músculo não foi alterada pela suplementação. Não houve diferença significativa (P>0,05) para espessura de gordura subcutânea, concentrações séricas de triglicerídeos, colesterol total, HDL e LDL entre os tratamentos controle e suplementação com cobre, independentemente da fonte. A suplementação com cobre alterou o perfil de ácidos graxos da carne (P<0,05), com aumento na proporção do ácido láurico (C12:0) do grupo controle comparado com os demais tratamentos (P<0,05). Houve redução da concentração de colesterol no músculo longissimus (P<0,05) dos cordeiros suplementados com Cu em relação ao grupo controle, acompanhado de redução (P<0,05) da concentração da GSH e aumento da GSSG no fígado (P<0,05). Não houve efeito da suplementação para níveis de TBARS no fígado (P>0,05), mas houve efeito significativo (P<0,10) no longissimus colhido no momento da desossa. A suplementação com Cu não teve efeito sobre os valores de TBARS para as amostras dispostas na vida de prateleira, porém, houve aumento linear desses valores ao longo do tempo. A suplementação com Cu aumentou a atividade da SOD e GP-x (P<0,05) no fígado. Estes resultados sugerem que o cobre pode ser usado para melhorar a qualidade de carne sem afetar a sua estabilidade oxidativa lipídica. / Copper is associated with lipid metabolism, becoming very important in reducing cholesterol and oxidative stability of meat, because it is part of some antioxidant enzymes. These attributes make interesting the research of this mineral in various animal species to improve the quality life of consumers, since they can reduce the risk of cardiovascular diseases and cancers, as well as of the suppliers of the meat due to the possibility of increase the shelf life and organoleptic characteristics. So the aim of this study was to determine the effect of two levels of copper sulphate and copper methionine on lipid and cholesterol metabolism and lipid oxidative stability in meat of Merino x Texel lambs. For that, an experiment was conducted in the Faculty of Animal Science and Food Engineering, University of São Paulo, at the Pirassununga Campus using forty male lambs, Merino x Texel, randomly distributed into 5 treatments groups of 8 animals each. The animals were housed in individualized cages for the study of sheep metabolism, for a period of 120 days. Treatments used were: control, without addition of Cu (Co); 10 or 30 mg of Cu/kg of DM in the form of Cu sulphate (CuSO4); 10 or 30 mg of Cu/kg of DM in the form of copper methionine (Cu-methionine). Liver biopsies were carried out in all animals to determine initial hepatic Cu level. On day 0, 28 and 56 of the experiment blood were collected for analysis of total cholesterol, HDL cholesterol (HDL) and triglycerides. At the end of the experiment, animals were humanely slaughtered and liver samples were collected for later for analysis of Cu, reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione peroxidase (GP-x), superoxide dismutase (SOD) and thiobarbituric acid reactive substances (TBARS). After 24 hours of cooling, left carcasses halves were sawed into two parts between the 12th and the 13th rib to obtain the fat thickness (EGSC). During sawing muscle sample from m. longissimus were collected for determination of cholesterol, fatty acids profiles and TBARS. At the same time, m. longissimus muscle entire was collected and frozen under vacuum for 12 months for study of oxidative stability. After that, steaks of m. longissimus were collected and exposed to \"display life\" (DL) (4°C) to study oxidative stability which was accompanied by TBARS values on days 0, 3 and 6. The copper supplementation resulted in higher concentration and accumulation of Cu in the liver (P<0.05), however, the concentration of Cu in muscle was not altered by supplementation (P>0.05). There was no significant effect (P>0.05) for fat thickness, serum triglycerides, total cholesterol, HDL and LDL between control and copper supplementation regardless of the source. The copper supplementation altered the fatty acid profile of the meat (P<0.05), with an increase in the proportion of lauric acid (C12: 0) in the control group compared with the other treatments (P<0.05). Copper supplementation reduced cholesterol concentration in m. longissimus (P<0.05) in supplemented lambs compared to the control group, this reduction was accompanied by reduction concentrations of GSH (P<0.05) and increasing of oxidized glutathione (GSSG) in the liver (P<0.05). There was no effect of Cu supplementation for TBARS in the liver however, there was significant effect on m. longissimus collected during sawing (P<0.10). There was no effect of Cu supplementation for TBARS in the m. longissimus exposed in the \"Display Life after 12 months vacuum freezing (P>0.05), but there was a linear increase in TBARS values during this period. Cu supplementation increased the activity of SOD and GP-x (P<0.05) in the liver. These results suggest that copper can be used to improve meat quality without affecting the oxidative stability.

by Leung Ho-yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references. / Abstract also in Chinese. / Acknowledgement --- p.i / Abstract --- p.ii / Table of Contents --- p.iv / List of Tables and Figures --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Methodology --- p.12 / Chapter Chapter 3 --- Experimental --- p.17 / Chapter 3.1 --- Sample Collection --- p.17 / Chapter 3.2 --- Preliminary Sample Treatment --- p.18 / Chapter 3.3 --- Dissolution Test Apparatus --- p.18 / Chapter 3.4 --- Reagents --- p.20 / Chapter 3.5 --- ICP Experimental Conditions --- p.21 / Chapter Chapter 4 --- Determination of Total Contents in Chinese Mineral Drugs --- p.28 / Chapter 4.1 --- Procedure --- p.28 / Chapter 4.2 --- Results --- p.39 / Chapter Chapter 5 --- Determination of the Effective Contents --- p.51 / Chapter 5.1 --- General Procedure --- p.51 / Chapter 5.2 --- Results --- p.52 / Chapter Chapter 6 --- Recovery Test for Dissolution --- p.77 / Chapter 6.1 --- General Procedure --- p.77 / Chapter 6.2 --- Results --- p.78 / Chapter Chapter 7 --- Discussion --- p.80 / Chapter 7.1 --- The Presence of Toxic Elements in many CMD --- p.80 / Chapter 7.2 --- Mass of Samples Added in the Dissolution --- p.80 / Chapter 7.3 --- Height of the Dissolution Paddle of the Dissolution --- p.81 / Chapter 7.4 --- Particle Sizes of the Sample in the Dissolution --- p.83 / Chapter 7.5 --- The Total and the Effective Contents --- p.83 / Chapter 7.6 --- Discussion for each CMD --- p.84 / Chapter 7.7 --- Conclusion --- p.103 / Appendix English 一 Chinese table of CMD --- p.108

The reduction and stabilization of atmospheric CO2 concentration is currently one of the most challenging problems being investigated. Carbon mineralization has recently received much attention as one of the most promising options for CO2 sequestration. The engineered weathering of silicate minerals as a means of permanent carbon storage has unique advantages such as the abundance of naturally occurring calcium and magnesium-bearing minerals and the formation of environmentally-benign and geologically stable solids via a thermodynamically favored carbonation reaction. However, several challenges need to be overcome to successfully deploy carbon mineralization on a large-scale. The current limitation of the carbon mineralization scheme for permanent storage of anthropogenic CO2 is the slow reaction kinetics, since the natural weathering of silicate minerals occurs on geological time-scales. Another problem of mineral carbonation is that the cost of the carbon mineralization process for sequestration is dominated by up front energy costs during the mineral processing and carbonation. In this study, chemically enhanced mineral dissolution via various chelating agents was investigated to accelerate the overall reaction rate of ex-situ and in-situ mineral carbonation. To reduce the overall cost of the carbon mineralization process, the utilization of solid products as value-added materials, e.g. precipitated magnesium carbonates (PMC) and precipitated calcium carbonates (PCC), was studied. Wollastonite (CaSiO3) and antigorite, which is a kind of serpentine (Mg3(OH)4(Si3O5)) group minerals, were selected for this work. They are representative of calcium silicate minerals and magnesium silicate minerals, respectively. This work starts with development of an experimental framework for the systematic investigation of mineral dissolution and carbonation behaviors with mineral pre-processing considerations (e.g., the removal of fines (< 5 μm) to standardize the reaction surface of the minerals), experimental set-up (e.g., syringe pump reactor for the investigation of mineral dissolution and high temperature, high pressure batch reactor for the study of direct aqueous mineral carbonation) and post reaction analyses (e.g., the evaluation of various carbon analysis techniques for the accurate estimation of the extent of carbon mineralization). Accelerated wollastonite weathering is experimentally studied first. For large scale carbon mineralization, generally Mg-bearing silicate minerals such as serpentine or olivine (Mg2SiO4) are the most suitable minerals due to not only their significant abundance in nature but also their high capacity. New York State, however, has one of the largest deposits of wollastonite in the United States and is considered to be a suitable place to adapt CO2 mineralization using Ca-bearing minerals as a CO2 storage option. Moreover, the technologies developed for enhancing carbonation of Ca-bearing minerals can also be applied to the industrial wastes with similar chemistry, such as steel slag and cement kiln dust. The effect of various types of chelating agents on the dissolution rate of wollastonite minerals is explored to accelerate its weathering rate. It is found that chelating agents such as acetic acid and gluconic acid can significantly improve the dissolution kinetics of wollastonite even at a much diluted concentration of 0.006 M by complexing with calcium in the mineral matrix. Calcium extracted from wollastonite is then reacted with a carbonate solution to form PCC, and the study shows that by controlling the reaction temperature, the morphological structure of the synthesized PCC can be tuned for various applications (i.e., paper fillers, plastic fillers and construction materials). Microbial and chemical enhancement of ex-situ and in-situ antigorite carbonation is investigated as well as synthesis of PMC to mimic commercially available CaCO3-based filler materials. The effect of various chelating agents, including volatile fatty acids produced via anaerobic digestion of food waste, on antigorite dissolution is investigated in a syringe pump reactor. It is found that oxalate performs best among over fifteen kinds of chelating agents on accelerating dissolution rate of antigorite minerals. Among the volatile fatty acids, valerate works best on antigorite dissolution followed by acetate. The concentration of valerate, however, is very low in the produced mixture of volatile fatty acids via anaerobic digestion. On the other hand, acetate is the dominant component in the mixture, so it is considered as the most valuable product of anaerobic digestion of food waste. Magnesium extracted from antigorite is then reacted with carbonates to form precipitated magnesium carbonates. The effects of various chelating agents, reaction time, reaction temperature and pH on the mean particle size, particle size distribution, composition, and particle morphological structures of precipitated magnesium carbonates are systematically studied. Finally, the effect of volatile fatty acids on direct aqueous mineral carbonation is studied in a high temperature, high pressure batch reactor with antigorite and olivine minerals to predict the effect of volatile fatty acids on in-situ mineral carbonation. Volatile fatty acids can enhance the overall reaction rate via direct aqueous mineral carbonation route slightly. Volatile fatty acids may be not good enough for accelerating ex-situ direct aqueous mineral carbonation. However, they may be suited to in-situ mineral carbonation, which takes years.

Acidithiobacillus ferrooxidans is a gram-negative bacterium that is able to extract energy from oxidation of Fe²⁺ and reduced sulfur compounds and fix carbon dioxide from atmosphere. The facts that A. ferrooxidans thrives in acidic pH (~2), fixes carbon dioxide from the atmosphere and oxidizes Fe²⁺ for energy make it a good candidate in many industrial applications such as electrofuels and biomining. Electrofuels is a new type of bioprocess, which aims to store electrical energy, such as solar power, in the form of chemical bonds in the liquid fuels. Unlike traditional biofuels made from agricultural feedstocks, electrofuels bypass the inefficient photosynthesis process and thus have potentially higher photon-to-fuel efficiency than traditional biofuels. This thesis covers the development of a novel bioprocess involving A. ferrooxidans to make electrofuels, i.e. isobutyric acid and heptadecane. There are four major steps: characterization of wild-type cells, engineering of medium for improved electrochemical performance, genetic modification of A. ferrooxidans and optimization of operating conditions to enhance biofuel production. Each is addressed in one of the chapters in this thesis. In addition, applications of A. ferrooxidans in biomining processes will be briefly discussed. An economic analysis of various applications including electrofuels and biomining is also presented. Wild-type A. ferrooxidans were first characterized in both batch and continuous cultures. A modified 9-K medium suggested by American Type Culture Collection (ATCC) was used as a starting point which has 72 mM Fe²⁺ at pH 1.8. The Fe²⁺ concentration and pH were varied in the experiments to assess their impacts on growth rate, cell yield (g cells/g Fe²⁺) and maintenance (energy used to keep cell viability). Citrate was added to the growth medium to dissolve precipitates which can be problematic in a continuous operation. It was found out that cells exhibited higher cell yield (g cells/g Fe²⁺) and lower maintenance with higher pH and addition of citrate. This indicates that cells grow in a more energy-efficient manner at such conditions since cells spend less energy in maintenance and more energy in biomass formation. Next the growth medium containing 72 mM Fe³⁺ and 70 mM citrate at pH 2.2 was explored during the electrochemical reduction of Fe³⁺. It turned out that electrochemical reduction of Fe³+ could not be carried out effectively due to a low electrolyte conductivity and low energy density of the medium. Citrate was also found to negative affect electrochemical performance due to a strong complexation with Fe³⁺. The conductivity was improved by adding 500 mM Mg²⁺ to the medium. Vanadium was used as an alternative redox mediator that has a much better solubility than Fe³⁺ to improve the energy density. Genetic modification was achieved by introducing genes from two foreign pathways i.e. valine synthesis and fatty acid synthesis into A. ferrooxidans to enable cells to produce either isobutyric acid (IBA) or heptadecane. Transformed cells were characterized based on the findings in wild-type cells. Isobutyric acid production was found to increase with increasing pH and Fe²⁺ concentration and addition of citrate. Further optimization of the growth medium was done by increasing Fe²⁺ to 288 mM, holding pH at 2.2 and using gluconate as the iron chelator instead of citrate. An economic analysis was performed on the electrofuel process and applications of genetically modified A. ferrooxidans in copper biomining processes. At electricity prices of $0.05/kWh, further improvement in biological efficiency needs to be achieved before the electrofuel process may become economically viable. The use of genetically modified cells in copper biomining process could open new opportunities to co-produce valuable chemicals and copper from the reduced material associated with the copper ores. The chemicals co-produced during copper processing could be sold for additional revenue or used on-site.

Cement has three sequential states in most applications: fluid, setting and hardened. This thesis focuses on the effect of nanoclays and diutan gum on rheological, chemical and mechanical properties corresponding to the three states. Water transport properties are critically important in many applications, such as oil well cementing and 3D concrete printing. The effect of nanoclays and diutan gum on water transport properties of cement pastes were investigated. Bleeding, water retention under suction pressure, and evaporation under air flow were measured. The nanoclay was found to reduce bleeding but had no effect on water retention or evaporation. The diutan gum was found to reduce bleeding, improve water retention, and decrease evaporation loss. The rheological properties of the pastes and their interstitial solution were also characterized to resolve the mechanisms underlying the water transport behaviors. Good correlation between the measured rheological parameters and water transport properties was found. In addition to water retention, the static yield stress build-up plays a major role in the successful oil well cementing and 3D concrete printing. Linear models are commonly used to describe the early structural build-up of cement-based materials. However, some studies have shown that there exists a faster non-linear phase before the linear phase. A simple non-linear thixotropy model is presented to describe the structural build-up process. It was quantified using static yield stress and storage modulus, which are measured through the stress growth protocol and small amplitude oscillatory shear (SAOS) tests, respectively. The effect of pre-shear, rest condition and nanoclay and diutan gum on the build-up behavior are studied. The results showed distinctly different trends between static yield stress and storage modulus. This may be attributed to the two different structures of fresh cement pastes, i.e. floc structures and C-S-H structures, measured by the stress growth protocol and SAOS test, respectively. Phase characterization of cement paste was performed through synchrotron x-ray diffraction technique. This allowed for real-time, in-situ measurements of x-ray diffraction patterns to be obtained, and subsequently the continuous formation and decomposition of select phases over time (up to 8 hours). Phases of interest included alite, ferrite, portlandite, ettringite, monosulfate, and jaffeite (crystalline form of calcium silicate hydrate). The effects of elevated temperatures at elevated pressure, as well as the effect of nanomaterial addition were investigated. Rate of conversion of ettringite to monosulfate increased with increasing temperature, and monosulfate became unstable when temperatures reached 85ºC. The synchrotron x-ray diffraction setup appeared to have captured the seeding effect of nano-sized attapulgite clays at 0.5% addition by mass of cement, where acceleration in the rate of formation of portlandite and jaffeite was observed. Finally, the investigated system was upscaled from cement paste to cement mortar incorporating the fly ash and the slag. The effect of the nanoclays on the mechanical properties was evaluated in comparison with the carbon nanotube. Compressive strength and tensile strength were evaluated. Results indicated that although the nanoclays are utilized primarily as a rheological modifier, they can also enhance mechanical properties.

O Brasil está entre os dez países que mais desperdiçam alimentos, com cerca de 35% da produção agrícola indo para o lixo. O processamento agroindustrial de alimentos é uma das atividades que mais geram resíduos, com aproximadamente 50% de matéria-prima sendo descartada. A falta de informações sobre a qualidade nutricional desses subprodutos agroindustriais não possibilita seu potencial aproveitamento na fabricação de produtos alimentícios. Neste contexto, o objetivo do trabalho foi realizar a caracterização química de subprodutos resultantes do processamento industrial de frutas e vegetais e do beneficiamento de cereais. Os elementos químicos Br, Ca, Co, Cr, Cs, Fe, K, La, Na, Rb, Sc e Zn foram determinados através da análise por ativação neutrônica instrumental, a composição centesimal, através de métodos preconizados pela AOAC, os fatores antinutricionais, através das determinações de ácido fítico e taninos e a disponibilidade dos nutrientes in vitro para os elementos Ca, Fe, K e Zn e pelo sistema de células Caco-2 para o Fe. A maioria das amostras contém alto teor de fibras e proteína e baixo teor de lipídeos e valor calórico. O farelo de arroz, a casca da semente de cupuaçu, a semente de cupuaçu e o bagaço de framboesa apresentaram as maiores concentrações de ácido fítico, entre 19,9 e 10,7 mg g-1. Já a casca de uva apresentou a maior quantidade de taninos (23,8 mg/g de catequina). As amostras apresentaram boa disponibilidade in vitro de Ca e Zn. Porém, para Fe e K, os valores ficaram abaixo de 10% disponível para a maioria das amostras. Na análise de biodisponibilidade através do sistema de células Caco-2, a amostra que apresentou maior quantidade de ferritina foi a casca de pepino (56,8 ng ferritina/\'mü\'g proteína). Observou-se que os subprodutos, geralmente, apresentam quantidade maior ou igual de nutriente que a parte usualmente consumida do alimento, além de apresentar disponibilidade de nutrientes compatível com outros alimentos de origem vegetal. Os dados sugerem que os subprodutos agroindustriais são potenciais ingredientes para a indústria alimentícia, podendo agregar valor nutricional em novos produtos. Estudos futuros e mais específicos para cada subproduto devem ser considerados, como análise sensorial e maneiras de aumentar a qualidade nutricional dos subprodutos / Brazil is amongst the ten countries that mostly waste food, with about 35% of agricultural production going to the trash. The agro-food processing is one of the activities which generate high amount of residues, with approximately 50% of raw material being discarded. The lack of information on the nutritional quality of agroindustrial byproducts does not enable its potential use in the manufacture of food products. In this context, the aim of this study was the chemical characterization of the by-products of industrial processing of fruits and vegetables and grain processing. The chemical elements Br, Ca, Co, Cr, Cs, Fe, K, La, Na, Rb, Sc e Zn were determined by instrumental neutron activation analysis. The proximate composition was evaluated by methods recommended by AOAC. The antinutritional factors, through the determination of phytic acid and tannins. The availability of nutrients in vitro for Ca, Fe, K and Zn and through the Caco-2 cells for Fe. Most samples contain high fiber and protein and low lipid content and calorific value. Rice bran, the peel of cupuaçu seed, the cupuaçu seed and the raspberry bagasse had the highest concentrations of phytic acid, between 19.9 and 10.7 mg g-1. The grape peel showed the highest amount of tannins (23.8 mg / g of catechin). The samples showed good in vitro availability for Ca and Zn, but the values for K and Fe were below 10% available for most samples. In the analysis of bioavailability through the Caco-2 cells system, the sample that showed the highest amount of ferritin was the peel of cucumber (ferritin 56.8 ng/\'mü\'g protein). It could be observed that the by-products generally exhibit similar or larger amounts of the nutrient than the food usually consumed, and nutrients availability compatible with other plant origin food. The data suggest that the agroindustrial byproducts are potential ingredients for the food industry and can add nutritional value to new products. Future studies more specific to each by-product should be considered like sensory analysis and ways to increase the nutritional quality of by-products

A Bahia tem sido, juntamente com Minas Gerais, Goiás e Rio Grande do Sul, destaque na produção de gemas naturais do Brasil, pais que detém grande parte das reservas mundiais desses bens minerais, com produção de gemas de qualidade reconhecidas internacionalmente. Os controles estatísticos registram a presença de mais de trinta variedades gemológicas em território baiano (Tavares et al, 1998). O quartzo é utilizado ultimamente em grande escala na produção de jóias. Isto se deve a sua grande abundância no território baiano, preços relativamente baixos de exploração, e a boa resposta do mesmo aos tratamentos térmico e de irradiação gema, visando mudanças ou o melhoramento da cor. As Serras do Espinhaço Setentrional e de Jacobina, bem como a região da Chapada Diamantina, concentram a maior parte das ocorrências de variedades, tanto coloridas como susceptíveis ao tratamento para induzir cor, deste mineral, o qual passou a ser visto como uma das principais matérias-prima para lapidários, comerciantes e joalheiros da região. Apesar da importância das mineralizações, existe uma carência de estudos científicos que abordem questões relacionadas com a evolução e controle geológico das mineralizações e com os tratamentos que são realizados para melhorar o potencial gemológico das regiões estudadas. Tendo em vista enriquecer o conhecimento deste potencial geológico do território baiano, a realização deste estudo representa um passo significativo no entendimento da evolução metalogenética das áreas estudadas, além de contribuir com o estudo geológico e gemológico das variedades coloridas do quartzo na Bahia. Os quartzos gemológicos estudados na Bahia encontram-se inseridos principalmente em ambientes hidrotermal, encaixados em rochas metareníticas e quartziticas do Supergrupo Espinhaço. A partir dos dados levantados em campo, pôde-se verificar que as mineralizações estudadas possuem um controle estrutural, e encontram-se posicionadas em fraturas de tração de baixo ângulo. Tais fraturas estão associadas com rampas de empurrão que se desenvolveram durante as deformações que culminaram com a estruturação do cinturão de dobramentos e cavalgamentos da Serra do Espinhaço. A cor da ametista é devido a presença de impurezas derivadas da família do ferro (FeO4)-4, e da radiação ionizante. O quartzo fumê desenvolve-se apenas com a presença de alumínio e lítio, e o fenômeno do \"centro de cor\" (defeito na estrutura cristalina causada pela falta de um elétron) é o responsável pela sua cor, onde o íon Al3+ ao substituir o íon Si4+ gera um desequilíbrio eletrônico que é compensado por íons de Li-. O citrino por sua vez, deve sua cor a uma combinação de AI-Li, semelhante ao do quartzo fumê. Os estudos também demonstraram que as aquisições de cores no quartzo obtidas através dos processos de irradiação gama e tratamento térmico, bem como a estabilidade das mesmas, estão amplamente condicionadas aos ambientes de formação dos cristais, e a presença de elementos químicos nos fluidos formadores dos cristais, os quais são responsáveis pela variação de suas cores. As características gemológicas encontradas demonstram que o quartzo baiano apresenta um elevado potencial comercial. Para o futuro sugere-se trabalhos de levantamentos geológicos e pesquisa mineral, desde que a exploração das gemas vem apresentando significativas reduções e limitações nas suas atividades minero-industriais, seja pela parcial exaustão das reservas conhecidas, ou pela necessidade de ampliá-las e, assim, incentivar novos investimentos. Pouquíssimos trabalhos com cunho gemológico tem sido publicados no Brasil com vista de esclarecer a correlação entre depósitos de quartzo e seu comportamento perante tratamentos de irradiação e de aquecimento. / Besides Minas Gerais, Goiás and Rio Grande do Sul, Bahia is worldwide known for its richness in minerals of industrial and gemological interest. Up to this day, more than 30 minerals of gemological use are known (Tavares et. al. 1998) One of the main gemological material is quartz, used currently in large amounts for jewelry due to its fair value and good response of color treatments by irradiation and heat. Most of the quartz is found and mined in the Espinhaço , Chapada Diamantina and Jacobina belts either as colorless quartz or as amethyst. The colorless variety is sometimes prone to treatments that induce color centers resulting in black (Morion), brown (Smoky), yellow(Citrine), green (Prasiolite) gemstones. Very few work exists dealing with the geological evolution, control of mineralization, estimation of quantities and possible treatments of these materials. The results of this work is a contribution to the knowledge of the metalogenic evolution of the studied areas and includes the location of all known occurrences of quartz from Bahia. It could be shown that most of the quartz from Bahia state is located mainly in a hydrothermal environment crosscutting the quartzites and arkosic rocks of the Espinhaço Supergroup. Field data showed strong tectonic control of the quartz veins, filling low angle traction fractures associated with the thrust belts that formed the Serra do Espinhaço mountain range. The fluids passing through these fractures deposited quartz, as amethyst (Breijinho de Ametista, Jacobina e Sento Sé), colorless and milky quartz and sometimes as citrine. The color of amethyst is due to substitutional iron with oxidation degree 4+, formed by irradiation of ferric iron contained in the tetrahedral of the quartz structure. Smoky colors are formed by irradiation of mainly Al containing quartz, whereas yellow and yellow green colors are formed by the presence of Al and Li. Few occurrences of colorless quartz forming a green variety by irradiation have been documented. Some preliminary results show that the type and intensity of color is determined by the specific environment of formation. More work is clearly needed to clarify the correlation of formation environment and color produced by irradiation and heat treatments.

O cobre está associado ao metabolismo de lipídios, sendo bastante importante na redução do colesterol, e à estabilidade oxidativa da carne, por fazer parte de algumas enzimas antioxidantes. Porém, quando na forma iônica, é considerado um elemento pró-oxidante. O cobre orgânico não apresenta esse efeito e, além disso, geralmente apresenta maior biodisponibilidade que fontes inorgânicas. Desse modo, o objetivo deste estudo foi determinar o efeito da suplementação com dois níveis e duas fontes de cobre (inorgânica e orgânica) sobre o desempenho, concentração de cobre no fígado, músculo e sangue, fermentação ruminal, parâmetros oxidativos e metabolismo de lipídios e colesterol. Trinta e cinco bovinos da raça Nelore em fase de terminação foram divididos em 5 grupos, com 7 animais por tratamento, conforme descrição: 1) C: Dieta controle, sem a suplementação adicional de cobre; 2) I10: suplementação de 10mg de Cu/kg de MS na forma de sulfato de cobre; 3) I40: suplementação de 40mg de Cu/kg de MS na forma de sulfato de cobre; 4) O10: suplementação de 10mg de Cu/kg de MS na forma de proteinato de cobre; 5) O40: suplementação de 40mg de Cu/kg de MS na forma de proteinato de cobre. A suplementação com cobre proporcionou maior concentração e acúmulo de Cu no fígado (p<0,05), sendo a maior média observada para o tratamento O40, porém, o status de Cu no músculo e no soro não foram alterados pelos tratamentos. A maior atividade da ceruloplasmina (p<0,05) foi observada para o tratamento I40. Não houve efeito significativo (p>0,05) para ganho de peso diário, ingestão de matéria seca, eficiência alimentar, rendimento de carcaça quente e fria, perda pelo frio, espessura de gordura subcutânea e área de olho de lombo dos bovinos, entre os tratamentos controle e suplementação com cobre inorgânico ou orgânico. O pH ruminal, os ácidos graxos voláteis e o nitrogênio amoniacal também não foram influenciados (p>0,05) pelos tratamentos. Em geral, a suplementação com cobre alterou o perfil de ácidos graxos da carne (p<0,05), com aumento na proporção de ácidos graxos insaturados em detrimento dos ácidos graxos saturados. Não houve efeito de tratamento para TBARS (substâncias reativas ao ácido tiobarbitúrico) no fígado e na carne embalada a vácuo (p>0,05), porém houve redução nos valores de TBARS na carne dos bovinos suplementados com Cu para as amostras dispostas no Display Life (tratamentos I40 e O40, p=0,06), e na atmosfera modificada (tratamentos I10, I40, O10 ou O40, p<0,05), em relação ao tratamento controle. A suplementação com Cu (tratamentos I40 e O40) aumentou a atividade da SOD (superóxido dismutase) (p<0,05), em relação ao tratamento controle, mas não influenciou a atividade da GSH-Px (glutationa peroxidase) (p>0,05). Não houve efeito da suplementação sobre triglicérides e colesterol no sangue; entretanto, em geral, houve redução da concentração de colesterol no músculo L. dorsi (p<0,05), em relação ao tratamento controle, através da redução (p<0,05) da concentração de GSH e da relação GSH/GSSG. / Copper is associated with lipid metabolism, becoming very important in reducing cholesterol, and with oxidative stability of meat, because it is part of some antioxidant enzymes. However, when in the ionic form, is considered a pro-oxidant element. The organic copper did not exhibit this effect and, besides, presents higher bioavailability than inorganic sources. Thus, the aim of this study was to determine the supplementation effect of two levels and two sources of copper (inorganic and organic) on the performance, Cu concentration in liver, muscle and blood, ruminal fermentation, oxidative parameters and metabolism of lipids and cholesterol. Thirty-five Nellore cattle in the finishing phase were divided into 5 groups with 7 animals per treatment, as described: 1) C: control diet, without additional Cu supplementation; 2) I10: 10mg Cu/kg DM, as Cu sulfate; 3) I40: 40mg Cu/kg DM, as Cu sulfate; 4) O10: 10mg Cu/kg DM, as Cu proteinate; 5) O40: 40mg Cu/kg DM, as Cu proteinate. Supplementation with copper provided higher Cu concentration and accumulation in the liver (p<0.05), with the highest mean observed for the O40 treatment, nevertheless the Cu status in muscle and serum were not affected by treatments. The highest activity of ceruloplasmin (p<0.05) was observed for the I40 treatment. There was no significant effect (p>0.05) for daily weight gain, dry matter intake, feed efficiency, hot and cold carcass yield, cold loss, backfat and loin eye area of cattle, among control treatment and supplementation with inorganic or organic copper. Ruminal pH, volatile fatty acids and ammonia were not influenced (p>0.05) by treatments. In general, copper supplementation altered the meat fatty acid profile (p<0.05), with an increase in the proportion of unsaturated fatty acids over saturated fatty acids. There was no treatment effect for TBARS (thiobarbituric acid reactive substances) in liver and meat vacuum packed (p>0.05), but there was a reduction in TBARS values in meat from cattle supplemented with Cu for samples prepared on Display Life (treatment I40 and O40, p=0.06), and modified atmosphere (treatment I10, I40, O10 and O40, p <0.05), compared to the control treatment. Supplementation with Cu (treatment I40 and O40) increased the activity of SOD (superoxide dismutase) (p<0.05) compared to control treatment, but did not influence the activity of GSH-Px (glutathione peroxidase) (p>0.05). There was no effect of supplementation on triglycerides and cholesterol in blood, however, there was a reduction in cholesterol concentration in L. dorsi muscle (p<0.05) compared to the control treatment, by reducing (p<0.05) of GSH concentrations and the GSH/GSSG ratio.