Rare earth mineral recovery from alternative resources such as coal and coal byproducts is increasingly important to provide an opportunity for economic recovery from U.S. sources. Currently, China produces the majority of the 149,000 tons of rare earth elements used annually worldwide of which the U.S. imports 11% or around 16,000 tons. There are no significant mining operations producing rare earth elements in the U.S. However, there are many U.S. sources containing rare earth minerals such as monazite including heavy mineral sand and phosphate operations. Monazite mineral particles of a few microns have also been detected in Fire Clay seam coal. Preliminary attempts to concentrate the rare earth mineral using flotation test results indicated that monazite was floated together with carbonate minerals. The flotation chemistry of a monazite-carbonate mineral system has received limited attention by researchers. As such, a systematic study of monazite flotation chemistry was conducted and the results reported in this dissertation. The surface charging mechanisms of monazite in aqueous systems were studied using electrokinetic tests, solution equilibrium calculation, crystal structure analysis, and electrostatic model prediction. The surface charge of monazite was found to be developed by protonation/deprotonation reactions. In other words, the hydrogen and hydroxyl ions were potential determining ions instead of the lattice ions of monazite. Electrokinetic tests of natural monazite mineral showed that the isoelectric point (IEP) occurred at pH 6.0. Solution equilibrium calculation and electrostatic model predictions of cerium monazite (CePO4) yielded an IEP of pH 7.2. The discrepancy between the two IEP values may be due to the different REE composition and/or the amount of carbon dioxide dissolved in solution. A common collector used to produce a hydrophobic monazite surface is octanohydroxamic acid. Adsorption studies found multilayer formation of octanohydroxamic acid on monazite surfaces at pH values of 3.0, 6.0, and 9.0. A kinetic study showed that the maximum adsorption density and rate for below monolayer coverage occurred at a solution pH value of 9.0, which was attributed to the chemical reaction between octanohydroxamate species and surface active sites (e.g., REE(OH)2+). For beyond multilayer adsorption, maximum adsorption occurred at pH 11.0 due to the abundance of hydroxyl ions in solution. The contributing effect of hydroxyl ions was proven by titration tests and FTIR analyses. When calcium ions existed in solution, specific adsorption of Ca(OH)+ on monazite surfaces occurred in both neutral and basic environments as indicated by the electrokinetic results. At low concentrations, Ca(OH)+ competed with octanohydroxamic acid for P-OH sites. However, higher dosages of Ca(OH)+ served as active sites for octanohydroxamic acid. The monazite floatability was negatively affected by the hydration of the adsorbed calcium species. The calcium ion dissolved from calcite mineral surfaces, which exist in the coal sources, provided an explanation for the depression of monazite in the combined systems. Single mineral flotation of monazite and calcite showed that sodium silicate and sodium hexametaphosphate efficiently depressed calcite while providing minimal effects on monazite recovery. However, in the monazite-calcite combined system, both monazite and calcite were depressed using the two regulators. Electrokinetic data and solution equilibrium calculations indicated that hydrolyzed species of calcium such as Ca(OH)+ interacted with silicates and formed a compact hydrophilic layer on monazite surfaces by hydrogen bonding and surface reaction. The compact layer decreased collector adsorption due to steric hindrance. Using 6×10-5 M EDTA together with 2.5×10-4 M octanohydroxamic acid and 0.05 g/L sodium silicate, monazite recovery of more than 90% was achieved while only recovering 20% of calcite. Based on the fundamental study, rare earth concentrates with 4700 ppm of REEs were produced from the Fire Clay fine coal refuse using column flotation.

The thesis starts by giving a motivation to materials modeling as a way to increase profitability but also a possibility decrease the environmental impact. Fundamental concepts of relevance for this work are introduced, this include the materials genome, ICME and of course the CALPHAD method. As a demonstration promising results obtained by an ICME approach using genetic algorithms and CALPHAD on the vacuum degassing process are presented. In order to make good predictive calculations and process models it is important to have good thermodynamic descriptions. Thus most part of the work has concerned the thermodynamic assessments of systems of importance for steelmaking, corrosion and similar processes. The main focus has been the assessment of sulfur-containing systems and thermodynamic descriptions of the Fe-Mn-Ca-Mg-S, Fe-Ca-O-S, Fe-Mg-O and Mg-Mn-O systems are presented. In addition, heat capacity measurements of relevance for the Mg-Mn-O system have been performed. To summarize the efforts some application examples concerning thermodynamic calculations related to steelmaking and inclusion formation are shown. / <p>QC 20160829</p> / COMPASS

Microchannels have been used in electronics cooling and in air conditioning applications as condensers. Little study has been made in the application of microchannels in automotive heat exchangers, particularly the radiator. The presented research captures the need for the design improvement of radiator heat exchangers in heavy-duty vehicles in order to reduce aerodynamic drag and improve fuel economy. A method for analyzing an existing radiator is set forth including the needed parameters for effective comparisons of alternative designs. An investigation of microchannels was presented and it was determined that microchannels can improve the overall heat transfer of a radiator but this alone will not decrease the dimensions of the radiator. Investigations into improving the air-side heat transfer were considered and an improved fin design was found which allows a reduction in frontal area while maintaining heat transfer. The overall heat transfer of the design was improved from the original design by 7% well as 52% decrease in frontal area but at the cost of 300% increase in auxiliary power. The energy saved by a reduction in frontal area is not substantial enough to justify the increase of auxiliary power. The findings were verified through a computational fluid dynamic model to demonstrate the heat transfer and pressure drop of microchannel tubes. The results confirmed that heat transfer of microchannels does improve the thermal performance of the radiator but the pressure drop is such that the net benefit does not outweigh the operating cost. An additional CFD study of the new fin geometry and air-side heat transfer predictions was conducted. The results of the study confirmed the theoretical calculations for the fin geometry.

Einstein’s equations are derived by following Jacobson’s thermodynamic method. It is seen that a family of possible field equations exist which satisfy the thermodynamic argument. Modified theories of gravity are addressed as possible candidates for replacing dark matter as an explanation for anomalous cosmological phenomena. Many of the proposed modified theories are not powerful enough to explain the currently observed phenomena and are rejected as viable theories of gravity. A surviving candidate, TeVeS, is further analyzed under the aforementioned thermodynamic argument to check for its consistency with thermodynamics.

Commercial aviation has demonstrated its ability to be a key driver of global socio-economic growth to this date. This growth, resulting from an ever increasing need for air-travel, has been observed to be environmentally unsustainable. Any technological enhancements to the upcoming fleet of aircraft or operational improvements have been overshadowed by this very demand for air-travel. Any further investigation into innovative concepts and optimisation approaches bring in trade-off difficulties due to limitations in current technology. This creates a constraint on design space exploration. The need to mitigate civil aviation’s environmental impact has necessitated this sector to expand its frontier and seek radical technologies. Among a range of other technologies, advanced biofuels for civil jet engines have been claimed to be one of the most promising solutions. “Techno-economic Environmental Risk Analysis (TERA) of Advanced Biofuels for Civil Aviation” is a study that contributes to knowledge through conception plus application of quantitative/ qualitative approaches to assess the technical viability, financial feasibility and environmental competence of 2nd and 3rd generation biojet fuels, through their application into the existing scenario of civil aviation, against that of the fossil-derived conventional jet fuel (Conv.Jet fuel). TERA of advanced biofuels aims to accomplish the aforementioned through a holistic, multi-disciplinary study entailing life cycle studies, carbon-foot printing, sustainability analysis, fuel chemistry, virtual studies comprising combustion thermodynamic, engine/aircraft performance and emission prediction, economic studies entailing biofuel price prediction and business case analysis as opposed to earlier studies. TERA of Advanced biofuels study entails development of elaborate life cycle models, ALCEmB (Assessment of Life Cycle Emissions of Biofuels) and ALCCoB (Assessment of Life Cycle Cost of Biofuels) to predict life cycle emissions and costs, respectively, of the advanced biofuels from the point of raw material generation to the point of finished product consumption (a “cradle-grave” approach). A virtual experiment, to assess the impact of the “performance” properties of the advanced biofuels on a representative twin-shaft turbofan/airframe combination, relative to that of Conv.Jet fuel, was also undertaken through numerical modelling and simulation.Evaluation through ALCEmB revealed that Camelina-SPK, Microalgae-SPK and Jatropha-SPK delivered 70%, 58% and 64% savings in life cycle emission, relative to Conv.Jet fuel. The Net Energy Ratio (NER) analysis indicates that current technology for the biofuel processing is energy efficient and technically feasible. An elaborate post-combustion gas property evaluation infers that the Bio-SPKs exhibit improved thermodynamic behaviour. This thermodynamic effect has a positive impact on mission-level fuel consumption which reflected as fuel savings in the range of 3 - 3.8% and, therefore, emission savings of 5.8-6.3% in CO2 and 7.1-8.3% in LTO NOx, relative to that of Jet-A1. An economic feasibility analysis which entails prediction of hypothetical biofuel price prediction and its impact on direct operating cost (DOC) of an aircraft which infers that Bio-SPKs, over a user-defined medium-range mission profile, costs an additional 95-100% in terms of aircraft DOC, relative to that operated with conventional Jet-fuel, within short (2020) and medium (2020). However, the advanced biofuels are able to exhibit financial competence from 2020 onwards, relative to that of Conv.Jet fuel. However, the Bio-SPKs exhibit this economic feasibility only against a backdrop of persistent Conv.Jet fuel price volatility and severe environmental taxation between the analysis periods (2020-2075).

<p>Protein biomarkers can facilitate the diagnosis of many diseases such as cancer and they can be important for the development of effective therapeutic interventions. Current large-scale biomarker discovery and disease state characterization studies have largely focused on the global analysis of gene and protein expression levels, which are not directly tied to function. Moreover, functionally significant proteins with similar expression levels go undetected in the current paradigm of using gene and protein expression level analyses for protein biomarker discovery. Protein-ligand interactions play an important role in biological processes. A number of diseases such as cancer are reported to have altered protein interaction networks. Current understanding of biophysical properties and consequences of altered protein interaction network in disease state is limited due to the lack of reproducible and high-throughput methods to make such measurements. Thermodynamic stability measurements can report on a wide range of biologically significant phenomena (e.g., point mutations, post-translational modifications, and new or altered binding interactions with cellular ligands) associated with proteins in different disease states. Investigated here is the use of thermodynamic stability measurements to probe the altered interaction networks and functions of proteins in disease states. This thesis outlines the development and application of mass spectrometry based methods for making proteome-wide thermodynamic measurements of protein stability in multifactorial complex diseases such as cancer. Initial work involved the development of SILAC-SPROX and SILAC-PP approaches for thermodynamic stability measurements in proof-of-concept studies with two test ligands, CsA and a non-hydrolyzable adenosine triphosphate (ATP) analogue, adenylyl imidodiphosphate (AMP-PNP). In these proof-of-principle studies, known direct binding target of CsA, cyclophilin A, was successfully identified and quantified. Similarly a number of known and previously unknown ATP binding proteins were also detected and quantified using these SILAC-based energetics approaches. </p><p>Subsequent studies in this thesis involved thermodynamic stability measurements of proteins in the breast cancer cell line models to differentiate disease states. Using the SILAC-SPROX, ~800 proteins were assayed for changes in their protein folding behavior in three different cell line models of breast cancer including the MCF-10A, MCF-7, and MDA-MB-231 cell lines. Approximately, 10-12% of the assayed proteins in the comparative analyses performed here exhibited differential stability in cell lysates prepared from the different cell lines. Thermodynamic profiling differences of 28 proteins identified with SILAC-SPROX strategy in MCF-10A versus MCF-7 cell line comparison were also confirmed with SILAC-PP technique. The thermodynamic analyses performed here enabled the non-tumorigenic MCF-10A breast cell line to be differentiated from the MCF-7 and MDA-MB-231 breast cancer cell lines. Differentiation of the less invasive MCF-7 breast cancer cell line from the more highly invasive MDA-MB-231 breast cancer cell line was also possible using thermodynamic stability measurements. The differentially stabilized protein hits in these studies encompassed those with a wide range of functions and protein expression levels, and they included a significant fraction (~45%) with similar expression levels in the cell line comparisons. These proteins created novel molecular signatures to differentiate the cancer cell lines studied here. Our results suggest that protein folding and stability measurements complement the current paradigm of expression level analyses for biomarker discovery and help elucidate the molecular basis of disease.</p> / Dissertation

Afin de lever le mystère centenaire qui entoure l'origine du changement de volume associé au dépliement des protéines globulaires, nous avons constitué une collection de 10 mutants du variant hyperstable de la SNase, ∆+PHS. Chacune de ces mutations a été conçue pour créer une nouvelle cavité ou agrandir une cavité existante au sein de la protéine. Dans un premier temps, nous avons analysé comment l'environnement structural local conditionne l'adaptation à la mutation. Les expériences de fluorescence sous haute pression ont montré un accroissement systématique de la différence de volume entre les états replié et déplié pour les 10 variants par rapport à ∆+PHS. Ce résultat majeur, qui s'ajoute à une étude récente démontrant que les effets d'hydratation ne contribuent pas de manière significative au changement de volume, démontre sans ambiguïté que la différence de volume entre les états replié et déplié est principalement due à la présence de cavités internes dans la structure native des protéines. Les mesures par RMN des changements de volume ont permis d'établir une cartographie des effets de la pression à l'échelle du résidu et d'identifier les intermédiaires de repliement peuplant le paysage énergétique. En analysant les cinétiques de dépliement, nous avons finalement pu caractériser les conséquences de ces mutations sur les états de transitions de la SNase. / To solve the century-old question of the origin of the volume change upon unfolding for globular proteins, we built up a collection of 10 mutants of the hyperstable variant of SNase, ∆+PHS. Each of these mutations was designed to create a cavity or to enlarge a naturally occurring cavity in the protein core. We first analyzed how the local structural environment determines the adaptation to the mutation. The high-pressure fluorescence experiments showed a systematic increase of the volume difference between the folded and unfolded states for the 10 variants, compared to ∆+PHS. This major result, in addition to a recent study demonstrating that the hydration effects do not provide any significant contribution to the volume changes, clearly demonstrates that the volume difference between the folded and unfolded states is predominantly due to the presence of internal cavities in the native structure. NMR measurements of the volume change allowed a mapping of the pressure effects on a residue scale and the identification of the folding intermediates populating the free-energy landscape. By analyzing the unfolding kinetics, we finally characterized the consequences of these mutations on the transition state ensembles of SNase.

Entrepreneurship is often perceived as a crucial component of economic growth and social development. Studies into entrepreneurship inform policy design, thus the diverse understanding of entrepreneurship among scholars can create confusion in policy design. The current state of the field of entrepreneurial research is examined in order to identify the need for a universal definition of entrepreneurship. After a synthesis and analysis of prior research is conducted to identify the various links in perspectives, a new definition and framework is suggested. The resulting framework sees entrepreneurship as an autocatalytic process of creation of meaning and the consequent retention of said meaning in the structure of a new venture. The elements of this framework (autocatalytic process, creation of meaning, and retention in structure) can be assigned varying degrees of importance corresponding to differing perspectives, while simultaneously ensuring the presence of each element. The developed framework can be used to better inform the decisions of scholars and policy makers, due to the uncovering of the complex relationships between society, individuals and firms.

Folding free energy of a protein is a delicate balance between stabilizing and destabilizing non-covalent itneractions. In this work, we decompose folding free energy into physically meaningful contributions, in which we aim to find general trends. Empirical potential is used to calculate interaction energy between all protein fragments, which are classified based on their dominant term in multipolar expansion. Calculations are done using 1200 non-redundant structures from PDB database. Based on the general trends found in interactions between these fragments, we attempt to better understand relationships between interaction energies calculated using computational chemistry methods and their corresponding free energy contributions on stabilization. 1

English abstract Hydrothermal systems related to highly evolved granitic magmas host diverse mineralization styles and provide an important source of economic metals. This master thesis concentrates on description and interpretation of geological structure, petrographic and textural variability, alteration zoning and calculation of time-integrated fluid fluxes recorded in highly evolved granites and tin-mineralized greisens of the Horní Blatná massif in the Western Krušné hory pluton. The massif is a composite intrusion, which consists of a large number of intrusive units emplaced during two stages. The first stage is represented by sparsely porphyritic fine-grained low-lithian annite granites that can be correlated with marginal granites (G2) of the Fichtelgebirge (Smrčiny) batholith or with intermediate granites (Walfischkopf type) of the Western Krušné hory (Erzgebirge) pluton. Intrusive batches of the second stage progressively evolve from medium- to coarse-grained serial high-lithian annite and zinnwaldite granites with topaz and rare tourmaline towards aphyric fine-grained zinnwaldite (or trilithionite) granites. This suite corresponds to the EIB2 and EIB3 facies of the younger intrusive complex in the Western Krušné hory (Erzgebirge) pluton and it can be compared to the G3 Waldstein and G4 units in...