<p> Stress-shortening data and the micro- and macro-fabrics or experimentally deformed calcite-cemented graywacke were analyzed in order to understand the nature of deformation in calcite-cemented rocks. Forty four room temperature triaxial experiments were conducted on the Blairmore sandstone in the range of 2.1 - 19.8 percent shortening, 1 - 2600 bars confining pressure, at strain rates on the order of lo-4/second. Under these condition, the normal transition from longitudinal fracture, at low confining pressure, to limited homogeneous flow, at high confining pressure is observed. The strength ( σ1, - σ3 ) increases from 2. 3 kilobars (kb) at 1 kb confining pressure (op), to 5.9 kb at 2.6 kb cp. At low confining pressures, deformation takes place primarily by brittle fracture of the calcitee At high confining pressures, the calcite deforms primarily by twinning, and the sand grains deform by fracturing parallel to σ1. The transition in deformational behavior of this rock is similar to the transition observed in orthooalcite rocks. However, in contrast to orthocalcite rocks, (1) strength is enhanced, (2) ductility is markedly reduced, end (3) the brittle-ductile transition is suppressed to much higher confining pressures. The behavior of this rock is analyzed by considering a two-phase model material consisting of a dispersion of strong, brittle particles within a weak and/or ductile matrix. Principles developed through the study of particulate reinforced composite engineering materials indicate that the mechanical behavior of these materials is dependent upon the mechanical interaction of the two phases. The sand grains act to constrain flow of the ductile matrix. Concurrently, plastic deformation within the matrix results in the development of stress concentrations within the nearly rigid sand grains. These enhanced stresses may result in the initiation and propagation of fractures within the sand grains. Propagation of the fractures is parallel to the maximum principal stress and the fractures characteristicly develop in this manner. Although the inherent physical properties of the individual phases determine the strain development within the individual phases, it is the interaction of the two phases which determines the unique behavior of the composite material. This behavior in turn controls the strength of the material and exerts an important influence on the development of the deformation fabric. The two-phase model not only provides insight into the behavior of calcite-cemented sandstones and other analogous rocks, but also makes it possible to predict how these rocks will behave when factors such as temperature and strain rate are permitted to vary. </p> / Thesis / Doctor of Philosophy (PhD)

No description available.

A study was conducted to assess the relationship between the zinc/copper ratio and risk factors (hypertension, obesity, elevated serum cholesterol and triglycerides, cigarette smoking, and exercise activity level) associated with susceptibility to cardiovascular disease. A questionnaire technique for assessment of physical activity was presented. The zinc/copper ratio was determined from the zinc and copper concentrations of hair samples obtained from sixty-four male subjects, ranging in age from 19 to 59 years. Correlation coefficients revealed no discernible relationship between either the zinc and copper content of hair, or the zinc/copper ratio obtained from these values. Serum cholesterol and triglyceride values, zinc concentrations in hair and the zinc/copper ratio were tested for significant differences associated with age. Statistical analysis indicated that these parameters were not significantly different. Such results were attributed to the wide range of variation within groups for this sample population. Data was not supportive of Klevay's altered zinc/copper ratio hypothesis as the major factor in the etiology of cardiovascular disease. / Ph. D.

Samples of garnet-grade Ashe formation schists, gneisses, and amphibolites from two drill holes through the Great Gossan Lead in southwestern Virginia have been studied petrographically and chemically. Metamorphic temperatures determined from the muscovite-paragonite solvus, the muscovite-calcite-quartz system, and Fe⇄Mg distribution in biotite and garnet are approximately 400-460°C. Using the sphalerite geobarometer, metamorphic pressures were found to have been equal to or greater than 4 kbar. Fine- to medium-grained garnet-chlorite-biotite-quartz-muscovite schists and gneisses predominate. Other lithologies include thin layers of hornblende amphibolite, sulfide ore, quartz veins, thin layers of hornblendic gneiss, marble lenses and minor solution cavities. The coarser-grained ore zone lithologies are dominated by chlorite, hornblende and actinolite-tremolite with cummingtonite rims, calcite, and quartz. Garnet-chlorite and garnet-biotite selvages are also occasionally found in the ore zone. The ferromagnesian minerals show marked iron depletion within 2-5 feet of the sulfide ore. Ore zone chlorite and biotite show a significant increase in magnesium; garnets show a similar increase in manganese. The cores of garnets from the ore zone show the influence of the ore even at the earliest stages of garnet growth, indicating that the ore was present prior to the peak of metamorphism. The distribution coefficients for Fe - Mg exchange reactions for garnet-biotite and garnet-chlorite also indicate that the ore and the surrounding rocks were metamorphosed together. Therefore, hypotheses for a synsedimentary or early hydrothermal origin for the ore are favored over those suggesting a post-metamorphic hydrothermal origin. / Master of Science

The object of writing this thesis was to present a brief history of the development of Texas minerals other than petroleum and sulphur.

The inversion temperature of cristobalite was investigated by incorporating TiO₂, AlPO₄, and BPO₄ into the cristobalite phase using solid state reactions. The combination of TiO₂ and AlPO₄ proved to be most effective in lowering the inversion temperature of cristobalite. Phase diagrams at the high silica corner were constructed for the respective systems. High cristobalite was stabilized for compositions prepared from the CaO-Al2₂O₃-SiO₂ and CuO-Al₂O₃-SiO₂ system using sol-gel processing. The stabilization mechanism is attributed to the surface energy effect resulting from the formation of fine crystals. The structural evolution from the x-ray amorphous gel to high cristobalite was examined by FTIR and Raman spectroscopy. The thermal expansion of the stabilized high cristobalite was characterized by high temperature x-ray. Changes in bond angle continue to dominate the thermal expansion of high cristobalite. / Ph. D.

The object of this paper is to make an analysis of the mineral and food content of the peanut and to compare them with a balanced food.

Student Number : 0215507F - PhD thesis - School of Mining Engineering - Faculty of Engineering and the Built Environment / The minerals sector in the Southern African Development Community (SADC) is considered to be the basis of economic reconstruction and development. After several decades of mineral extraction, SADC member States are still grappling with how the sector can contribute to the broader economy and achieve sustainable development. The sector has the potential to fulfill these national aspirations if appropriate policies are developed. In the context of the SADC, the thesis argues that since most of the population is rural-based, strategies for meaningful mineral development must take into account the concerns of these people. Policy defines a vision and aspiration, and articulates what a nation wishes to do with its mineral resources. The process of policy development is therefore crucial to ensure that the concerns of several stakeholders are considered and consensus is reached on actions to be taken for beneficial mineral extraction. The thesis shows a process of mineral policy development that result in the identification of key areas of emphasis to address concerns of the majority of the population in a country. The process has been applied in the development of mineral policies in Namibia and Malawi during this study. The outcomes address broad and specific social, economic and environmental issues that are consistent with sustainable development. Since the SADC countries have similar problems and opportunities, once all States have articulated minerals policies using this process, a regional approach or policy can be derived. This study illustrates such a policy framework.

O estudo tem como objetivo propor método de avaliação de efeito econômico do manejo dos dejetos com a utilização de diferentes estratégias nutricionais de suínos em crescimento e terminação. Especificamente, procura-se: i) Calcular as margens de comercialização para as diferentes estratégias nutricionais; ii)Avaliar o efeito econômico das diferentes estratégias nutricionais na excreção e aproveitamento de nutrientes pelos animais; iii) Valorar o consumo de água dos animais; iv) Valorar os dejetos gerados pelos suínos em relação ao seu potencial uso como fertilizante orgânico; v) Avaliar o impacto de cada estratégia nutricional sobre o custo do armazenamento (esterqueira) e uso dos dejetos, e sobre o seu tratamento por biodigestor e posterior utilização; vi) Avaliar a viabilidade econômica dos diferentes sistemas nutricionais e posterior utilização dos dejetos como fertilizante orgânico após tratamento por biodigestor e esterqueira. Os tratamentos a partir dos quais os dados foram obtidos são: T1: Dieta com nível alto de proteína bruta e suplementação mínima de aminoácidos (Dieta Controle); T2: T1 com redução do nível de proteína bruta, mediante a suplementação de lisina, metionina, treonina e triptofano industriais, considerando o conceito de proteína ideal; T3: T1 com a inclusão de 0, 010 (%/kg de dieta) fitase e redução dos teores de cálcio e fósforo da dieta; T4: T1 com a suplementação de 40% de minerais orgânicos (Cu, Zn e Mn) e 50% de minerais inorgânicos; T5: T1 combinando os tratamentos descritos anteriormente. As análises estatísticas foram realizadas utilizando o pacote computacional SAS, com nível de significância de 5%. As características de desempenho zootécnico, peso médio, consumo médio de ração, ganho médio de peso e conversão alimentar e as margens de comercialização não apresentaram diferenças significativas nos diferentes tratamentos e períodos. Os tratamentos T4 e T5 apresentaram melhor eficiência na utilização de nutriente e menor excreção dos nutrientes.Os tratamentos T5 e T4 apresentaram menor consumo e menor custo na valoração da água. A valoração dos dejetos foi favorável ao T1 com maior quantidade de NPK. Os tratamentos ambientalmente mais eficientes apresentaram menores custos na construção da esterqueira e biodigestor em ambos os materiais, PVC e PEAD; os mesmos tratamentos apresentaram menor potencial fertilizante; o caminhão com tanque de 15t apresentou menores custos no transporte e distribuição dos dejetos. Em todos os cenários avaliados dos diferentes sistemas nutricionais e posterior utilização dos dejetos como fertilizante orgânico após tratamento por biodigestor e esterqueira foram viáveis economicamente com payback de um ano. Os métodos ambientais propostos se mostraram válidos, pois foram capazes de identificar que dietas com maior aporte tecnológico apresentaram vantagens frente à dieta controle, entretanto economicamente o T1 apresentou maior quantidade na produção e consequente valoração de NPK. / The study aims to propose economic effect evaluation method of manure management with the use of different nutritional strategies of growing and finishing pigs. Specifically, the objectives were: i) To calculate marketing margins for the different nutritional strategies; ii) To evaluate the economic effect of different nutritional strategies on excretion and utilization of nutrients by the animals; iii) Valuing water consumption of animals; iv) Valuing the waste generated by the pigs in relation to its potential use as organic fertilizer; v) Valuing the impact of each nutritional strategy on storage cost (composting) and use of waste products, and about their treatment by bio-digester and later use; and vi) Valuing the economic viability of the different nutritional systems and subsequent use of manure as organic fertilizer after treatment by bio-digester and composting. The treatments from which data were collected were: T1: diet with high level of crude protein and minimum supplementation of amino acids (Control Diet); T2: Diet T1 with a reduction in the level of crude protein by supplementation of lysine, methionine, threonine and tryptophan, assuring the industrial ideal protein of all essential amino acids; T3: T1 with the inclusion of 0.010 phytase (%/kg diet) and reduction of the levels of calcium and phosphorus in the diet; T4: T1 with 40% supplementation of organic minerals (Cu, Zn and Mn) and 50% of inorganic minerals; T5: T1 combining the treatments described previously. Statistical analyses were performed using SAS computing package, with a significance level of 5%. The performance characteristics, average weight, average consumption of rations, average gain of weight and feed conversion and marketing margins showed no significant differences in the treatments and periods. The treatments T4 and T5 showed better efficiency in nutrient utilization and lower nutrient excretion. The T5 and T4 treatments showed lower consumption and lower cost at valuation of water. The valuation of the manure was favorable to T1 with largest amount of NPK. Environmentally efficient treatments showed lower costs in building the composting and biodigester in both materials, PVC and PEAD; the same treatments showed lower potential fertilizer; the tank truck 15 m3 presented lower costs in transportation and distribution of manure. In all scenarios evaluated the different nutritional systems and subsequent use of manure as organic fertilizer after treatment by bio-digester and composting were economically viable with payback of one year. Environmental methods proposed were valid, because they were able to identify that diets with higher technological contribution presented advantages the control diet, however economically the T1 was more quantity in production and consequent valuation of NPK.

Rising concentration of CO2 in the atmosphere is attributed to increasing consumption of fossil fuels. One of the most effective mechanisms to store CO2 captured from power plants is via geological injection of CO2 into formations that contain calcium and magnesium silicate and alumino-silicate minerals and rocks. The mechanism that ensures permanent storage of CO2 within rocks is mineral carbonation. When CO2 is injected into mineral or rock formations rich in calcium or magnesium silicates, they react with CO2 to form calcium or magnesium carbonates, which is also known as carbon mineralization. Calcium and magnesium carbonates are stable and insoluble in water. However, the kinetics of in-situ mineral carbonation involve CO2 hydration, mineral dissolution and formation of carbonates, and the relative rates of these phenomena when coupled, are not very well understood. In this study, the coupled interactions of CO2-reaction fluid-minerals were investigated to determine the optimal conditions for carbon mineralization, and to identify the chemical and morphological changes in the minerals as they react to form carbonates. Carbon mineralization in various minerals and rocks such as olivine ((Mg,Fe)2SiO4)), labradorite ((Ca, Na)(Al, Si)4O8), anorthosite (mixture of anorthite (CaAl2Si2O8), and basalt (rock comprising various minerals) were studied at high temperatures (Tmax = 185 oC) and high partial pressures of CO2 (PCO2, max = 164 atm) which are relevant for in-situ conditions. These minerals and rocks differ considerably in their chemical compositions and reactivity with CO2. A systematic comparison of the effects of reaction time, temperature, partial pressure of CO2, and fluid composition on the conversion of these magnesium and calcium bearing minerals and rocks showed that olivine was the most reactive mineral followed by labradorite, anorthosite, and basalt, respectively. Previous studies at Albany Research Center (Gerdemann et al., 2007; O'Connor et al., 2004) reported that a solution of 1.0 M NaCl + 0.64 M NaHCO3 was effective in achieving high extents of carbonation in olivine, heat-treated serpentine, and wollastonite. However, the independent effects of NaCl and NaHCO3 and their role in mineral carbonation were not sufficiently explained. In this study, the role of varying concentrations of NaCl and NaHCO3 on carbon mineralization of various minerals was elucidated. NaHCO3 buffered the pH and served as a carbon carrier, resulting in higher carbonate conversions. Except in the case of olivine, NaCl had a negligible effect on enhancing mineral carbonation. Unlike NaHCO3, NaCl does not buffer the pH or serve as a carbon carrier, but Cl- may serve as a weak chelating agent can complex with Mg or Ca in the mineral matrix to enhance dissolution. The competing effects of ionic strength and pH swings as the mineral dissolves and carbonation further complicate the role of NaCl on mineral carbonation. Based on the experimental methodologies developed to study carbon mineralization in minerals and rocks at high temperatures and pressures, alternative applications such as the remediation of hazardous alkaline wastes such as asbestos containing materials were identified. Asbestos is composed of chrysotile, a fibrous hydrated magnesium silicate mineral and a form of serpentine known to cause respiratory illnesses. By treating asbestos containing materials with CO2 in the presence of 0.1 M Na-oxalate, dissolution of chrysotile and precipitation of newer phases such as glushinkite (Mg(C2O4)* 2H2O) and magnesite (MgCO3) occurred, which reduced the chrysotile content in asbestos. Based on the methodologies for studying mineral dissolution and carbonation kinetics, and coupled mineral dissolution and carbonation behavior, a scheme for connecting laboratory scale experiments with simulations to estimate the uncertainties associated with carbon mineralization was developed. The effects of temperature, different dissolution rates, and varying levels of surface area changes due to passivation or reactive cracking on the rates of carbon mineralization were simulated using PhreeqC, a computer program developed for geochemical speciation calculations (Parkhurst & Appelo, 1999). Various studies proposed that microfractures and cracks may occur in geologic formations due to the extensive growth of carbonate crystals (Kelemen & Hirth, 2012; Kelemen & Matter, 2008; Matter & Kelemen, 2009; Rudge et al., 2010). Other studies have suggested that the formation of carbonates may plug the pore spaces and limit further reactivity (Hövelmann et al., 2012; King et al., 2010; Xu et al., 2004). The effects of changes in surface area due to the formation of microfractures or passivation due to carbonate growth on the rates of carbon mineralization were also simulated. Overall the results of these studies demonstrate the effect of various parameters on carbon mineralization and how these parameters can be connected to predict CO2 storage in mineral formations. The frameworks to connect laboratory scale experiments with simulations to determine carbon mineralization rates and to assess the risks associated with CO2 injection in reactive formations, can be used to direct future research efforts to predict the fate of injected CO2 with greater accuracy for sensor placement and optimization of CO2 monitoring technologies.