Thesis advisor: Hiroshi Nakazato / Microcredit has been praised and criticized for its reputation as the solution to global poverty—helping the poor help themselves. The economists have focused on the impossibility of a sustainable microfinance system, whereas other scholars have commended the social advancements that MFIs have supported, especially in relation to gender inequality. This conceptual thesis specifically studies the effects of microfinance institutions on women’s empowerment—first defining ‘empowerment’ and then observing it in various case studies. My research supports the conclusion that microfinance is a useful economic aid and more importantly it spearheads the fight for women’s rights. / Thesis (BA) — Boston College, 2011. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: International Studies Honors Program. / Discipline: International Studies.

The effective separation of ammonia from the synthesis loop in ammonia synthesis plants is an important step in its manufacture. This work presents the use of nanocomposite MFI zeolite membranes prepared by a pore-plugging method for this separation process. Performance of a zeolite membrane is highly dependent on the operating conditions. Therefore, the influences of differential pressure, temperature, sweep gas flow, feed gas flow and gas composition are studied experimentally. Transport of NH3 in this membrane is by surface diffusion in the intracrystalline (zeolite) pores in parallel with capillary condensation in the intercrystalline (non-zeolite) pores. The separation of NH3 from a mixture with H2 and N2 is by preferential adsorption of NH3, which hinders the permeation of weakly adsorbed H2 and N2. Differential pressure has only relatively small effects in the pressure range 300kPa – 1550kPa. Increase in sweep flow rate has little effect on NH3 gas permeance, but H2 and N2 permeances increase thereby decreasing the selectivities. Increase in feed flowrate also has little effect on NH3 permeance. However, the N2 and H2 permeances increase and there is a subsequent decrease in selectivities. Membrane performance was found to be highly dependent on temperature. NH3 permeance in the mixture increases linearly with temperature. NH3 selectivity was found to increase with temperature up to 353K after which it starts to decrease due to N2 and H2 permeances increasing with temperatures beyond 353K (αNH3/N2 = 46 and αNH3/H2 = 15) and is therefore the optimum temperature for separation. A potential barrier model is developed to describe the hindering effect of NH3 on H2 and N2 permeance. The model fails to predict correctly H2 and N2 permeances in the ternary mixture using pure gas (H2 and N2) permeances. Binary mixture permeation H2/N2 studies showed that there are diffusion effects (single file diffusion) that have not been taken into account in the potential barrier model. When permeances of the individual components in the binary mixture are used in the model instead of the pure gas permeances, there is an improved agreement between experimental and predicted results.

Thesis (M. Sc. (Chemistry)) -- University of Limpopo, 2016 / In this study, the use of synthetic hierarchical MFI zeolites as supports for palladium hydrocracking catalysts was investigated. Hierarchical zeolites were synthesised through two different routes, viz., (i) the indirect and (ii) direct routes. In (i) pristine ZSM-5 zeolites with different SiO2/Al2O3 ratios (SARs) were synthesised hydrothermally using tetrapropylammonium bromide as structure-directing agent (SDA), followed by a brief desilication of its calcined form in 0.2 M NaOH solution at 65 °C for 0.5 h. Procedure (ii) involved prior synthesis of three polyquaternary ammonium surfactants (containing 2 - 4 ammonium centres), followed by their use as SDAs in the hydrothermal synthesis of hierarchical MFI zeolites. The resulting materials were characterised by XRD, FT-IR, SEM and N2 adsorption isotherms (including BET surface area measurements). Successful synthesis of different classes of the hierarchical MFI zeolites was confirmed by XRD patterns, while successful synthesis of polyquaternary ammonium surfactants was confirmed by both their 1H NMR spectra and their ability to direct the MFI structure. On the basis of IR, peak intensities in the OH region between 3500 and 3800 cm-1, the surfactant-templated zeolites were inferred to be more acidic than zeolites prepared through the desilication route. Significant changes in crystal morphology were observed upon desilication of ZSM-5(50), while the ZSM-5(77) and ZSM-5(100) retained their agglomerated morphology upon a similar treatment. The micrograph pristine of ZSM-5(50) showed a predominant morphology of large and small spheroids, together with some ill-defined cubic shapes. After desilication, the zeolite did not retain the original morphology entirely, showing hexagonal prismatic crystals with twinning occurring in other areas and large spheroids “hatching” to reveal their contents upon treatment. Desilicated zeolites exhibited improved textural properties (i.e., increased SBET, pore volumes and pore diameters) and minor structural readjustments compared to their pristine counterparts. Textural properties of surfactant-templated zeolites were superior to those of desilicated zeolites, and improved with increasing number of quaternary ammonium centres in the surfactant template. These materials were generally more crystalline than the conventional zeolites. Hydrocracking catalysts containing 0.9 wt.% Pd loading on different MFI supports were prepared by the incipient wetness impregnation method. The n- v hexadecane hydrocracking conditions used were typical of LTFT process (i.e., Temperature = 215 - 310 °C, WHSV = 1 h-1, Pressure = 20 bar, in addition to the H2 /n-C16 ratio of 10). The catalytic activity in all catalyst systems increased with increasing reactor temperature and displayed C4/C12 ratios ≠ 1, evidence of the occurrence of secondary cracking (i.e., a non-ideal hydrocracking behaviour). This was also supported by the shapes of their product distribution profiles, which showed dominant C3 - C7 n-paraffins. Co-feeding H2O with n-C16 into the reactor was found to be detrimental to n-C16 conversion, but promoted the selectivity to iso-paraffins in the product spectrum. Simultaneous introduction of CO and H2O aggravated secondary cracking. Amongst the pristine ZSM-5 zeolite-based catalysts, Pd/P-ZSM-5(77) showed the best catalytic performance. Upon desilication, the performance order changed to favour Pd/D-ZSM-5(50*). For the surfactant-templated supports, Pd/HSZ(N4) showed the most superior hydrocracking performance. Comparison of catalytic activities of the best performing catalyst systems derived from the conventional and surfactant-templated zeolites in the hydrocracking of n-hexadecane, follow the order Pd/D-ZSM-5(50*) > Pd/P-ZSM-5(77) > Pd/HSZ(N4). That is, the pristine and desilicated zeolite-based catalysts performed better than their surfactant-templated zeolite-based counterparts. Therefore, the post-synthesis generation of mesoporosity through desilicating ZSM-5 with a SAR of 50 has proven beneficial for the resulting catalyst system. One of the possible reasons for the relatively inferior hydrocracking performance of the Pd/HSZ(N4) catalyst may be the aluminium-richness of the support (SAR = 40) compared to the conventional ZSM-5-based supports. In summary, catalysts Pd/D-ZSM-5(50*), Pd/P-ZSM-5(77) and Pd/HSZ(N4) are promising for diesel-selective catalysis and need further refinements and exploration.

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No description available.

Zeolite membranes are attractive materials to separate gas and liquid mixtures. MFI is a widely studied zeolite type due to its ease of preparation and comparable pore size with the molecular size of many substances. In this study MFI type membranes were synthesized over porous &amp / #945 / -Al2O3 supports and characterized with XRD, SEM and gas permeation measurements. In the first part of this study the effect of soda concentration of the synthesis solution on the membrane morphology and crystal orientation was investigated. The synthesis was carried out from solutions with a molar composition of (0- 6.5)Na2O:25SiO2:6.9TPABr:1136H2O at 150oC. At soda concentrations between 0.45 and 1.8 the membrane layers with (h0h)/c-directed orientation were obtained. At lower and higher soda concentrations membrane layer formed from randomly oriented crystals. The (h0h)/c-oriented membranes showed H2/n-C4H10 ideal selectivities of 478 and 36 at 25&deg / C and 150&deg / C, respectively.In the second part, MFI membranes were synthesized from mixtures with different concentrations of template molecules. Tetrapropylammonium hydroxide, tetrapropylammonium bromide or mixture of both types were used as template. The nucleation period, the size of MFI crystals, membrane thickness decreased as the tetrapropylammonium hydroxide concentration increased. Besides conversion of SiO2 in the synthesis solution to MFI passed through a maximum with increasing concentration of tetrapropylammonium hydroxide in the synthesis solution. When tetrapropylammonium bromide was used as template thicker membranes were obtained. In the third part MFI type membranes with a thickness of 1.5-2 &amp / #956 / m were synthesized by mid-synthesis addition of silica to the synthesis medium. The membranes synthesized with and without mid-synthesis addition of silica have n-C4H10/i-C4H10 ideal selectivities of 47 and 8 at 100oC, respectively. The change of composition during the synthesis increases the crystal growth rate and the size of the crystals forming the membrane, thus better quality membranes can be obtained by mid-synthesis addition of silica to the synthesis medium. In the last part of this study, thin MFI type zeolite membranes were synthesized in a recirculating flow system at 95&deg / C on the inner side of the tubular &amp / #945 / - alumina supports. A membrane synthesized by two consecutive synthesis steps had a separation selectivity of 38 and 86 for equimolar mixtures of n- C4H10/CH4 and n-C4H10/N2 at 25oC, respectively. The membrane selectively permeated large n-C4H10 over small CH4 and N2, suggesting that the separation is essentially adsorption-based and the membrane has few nonselective intercrystalline pores.

abstract: The microfinance industry provides financial services to the world's poor in hopes of moving individuals and families out of poverty. This dissertation document suggests that information and communication technologies (ICTs) are changing the microfinance industry, especially given recent advancements in mobile banking, Internet usage and connectivity, and a decreasing digital divide. These impacts are discussed in three essays. First, ICTs impact intermediation among various players in the microfinance industry. Second, ICTs impact the extent to which microfinance institutions (MFIs) extend their outreach to poorer or more geographically remote borrowers. Finally, ICTs impact the location of decision rights given newly forming peer-to-peer (P2P) social microlending organizations. As the microfinance industry increases its adoption and reliance on ICTs, new and interesting opportunities abound for researchers in the information systems discipline. / Dissertation/Thesis / Ph.D. Business Administration 2012

Orientador: Lucia Galvão de Albuquerque / Resumo: As características de qualidade de carne, por serem de difícil mensuração, raramente são contempladas em programas de melhoramento genético. Porém, é necessário conhecer sobre os genes e os mecanismos moleculares que controlam essas características, isso poderá auxiliar na avaliação de animais de forma precoce. Objetivo desse estudo foi identificar e analisar genes e isoformas de mRNA diferencialmente expressos no tecido do músculo Longissimus thoracis de bovinos da raça Nelore, fenotipicamente divergentes para características cor da carne, marmoreio e maciez da carne (avaliada através das metodologias de WBSF e MFI) usando dados de RNA-Seq. Além disso, esse estudo visa a identificação dos efeitos de variantes estruturais em “splice sites” de transcriptos diferencialmente expressos em animais fenotipicamente divergentes para as características de color e marmoreio da carne. Uma média de 37 mil transcritos foram detectados sendo expressos no músculo de bovinos Nelore. Foram identificados 40 e 28 isoformas de mRNA (p-valor < 0,001) diferencialmente expressas para os fenótipos de WBSF e MFI, respectivamente. Além disso, foram identificados sendo diferencialmente expressos os mRNAs [WBSF (SYNPO-201) e MFI (ANKRD23-202)], e entre outras isoformas de mRNA relacionadas a genes que afetam a velocidade de degradação das fibras musculares durante o processo de envelhecimento da carne, como e.g. [para WBSF (MYOT, CASQ1, TPM2, MB e SYNM) e para MFI (FGFRL1 e NEB)]. Na análise de enriquec... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The measurement of meat quality traits are costly, because of that it is rarely included in breeding programs. However, it is necessary to know about the genes and the molecular mechanisms that control these traits, this may help in the evaluation of animals at an early stage.Thus, the identification of mRNA isoforms and the associated splice variants affecting meat quality traits in Nellore cattle could allow to better understanding the genetic architecture of these complex traits. The objective of this study was to identify and analyze genes and mRNA isoforms differentially expressed in the Longissimus thoracis muscle tissue of Nellore cattle, phenotypically divergent for meat color, marbling and meat tenderness (evaluated using WBSF and MFI methodologies) traits, using RNA-Seq data. In addition, to identify structural variants affecting splice sites of differencially expressed mRNA isoforms for marbling and meat color traits. An average of 37 thousand transcripts were detected in the Nellore muscle transcriptomic analysis. A total of 40 and 28 mRNA isoforms (p-value |<| 0.001) were differentially expressed between divergent groups for WBSF and MFI phenotypes, respectively. The differentially expressed mRNA isoforms [WBSF(MYL1, MYL3, MYH1 and MYBPC2) and MFI (MYL6) traits], which are myosin encoders, was the family with most abundantly number of mRNA isoforms detected as diferencially expressed. In addition, we identified as DE [WBSF (SYNPO-201 isoform) and for MFI (ANKRD23... (Complete abstract click electronic access below) / Doutor

Les zéolithes représentent une importante classe de catalyseurs hétérogènes largement utilisées dans l’industrie. En effet, ce sont des catalyseurs de choix pour de multiples réactions grâce à leurs propriétés uniques largement modulables, à savoir leur forte acidité de Brønsted, leur grande surface spécifique, leur stabilité hydrothermique et leur sélectivité de forme. Cependant, la taille de leur micropores engendre des difficultés en terme de diffusion, réduisant ainsi leur potentiel catalytique. Ainsi, la conception sur mesure, en fonction de l’application finale, semble être une méthode très intéressante pour le développement de nouveaux catalyseurs zéolithiques.Les travaux réalisés au cours de cette Thèse ont pour objectif la conception de zéolithes à trois échelles : (i) au niveau du site actif en jouant sur la force acide et sur leur accessibilité, (ii) au niveau macroscopique par la taille des cristaux et (iii) au niveau du réacteur en les déposant sur divers supports. Ces différentes zéolithes ont été évaluées dans deux réactions acides : la chloration d’aromatiques et la conversion du méthanol en oléfines légères (MTO).Des zéolithes hiérarchisées ont été synthétisées selon diverses méthodes pré- ou post-Synthétiques et testées dans la chloration du nitrobenzène et du chlorobenzène. De plus, des cristaux « géant » de ZSM-5, préparés par voie fluorure, ont été évalués dans le MTO.La corrélation directe entre l’activité catalytique et les propriétés intrinsèques des zéolithes a permis de souligner les propriétés indispensables à chaque réactions. / Zeolites are aluminosilicate catalysts of great importance for the chemical industries. Their unique properties, i.e., strong Brønsted acidity, high surface area, high hydrothermal stability, and shape selectivity, combined with an extensive tunability, render them the candidate of choice in various reactions. Nevertheless, often only a fraction of their potential is exploited, due to access and diffusion limitation to/in their micropores. In this field, the rational design appears as a valuable method to design new zeolite catalysts, according to their targeted application.The work described in this Thesis aims in the design of zeolites at three levels: (i) acid site by playing on the acid strength and on the accessibility, (ii) microscopic scale by adapting the crystal size and (iii) reactor level by coating zeolite crystals on different supports. These as-Prepared zeolites were evaluated in two acid-Catalyzed reactions: the aromatics chlorination and the conversion of methanol in light olefins (MTO).Hierarchical zeolites were synthesized according to several pre- or post-Synthetic modifications and evaluated in nitro- and chlorobenzene chlorinations. Besides, “giant” ZSM-5 zeolites, prepared according to fluoride-Mediated route, as well as zeolite coatings on β-SiC, were tested in the MTO reaction.Thanks to a direct correlation between catalytic activities and intrinsic properties, optimal catalyst properties were highlighted in both reactions.

La pyrolyse rapide de biomasse lignocellulosique produit des bio-huiles avec des rendements élevés mais ces liquides contiennent de nombreux composés oxygénés, une acidité élevée et de ce fait sont instables. Un hydrotraitement poussé de ces huiles est nécessaire avant qu'elles puissent être utilisées comme combustibles liquides. Afin de réduire le coût et d'améliorer les performances de l'hydrotraitement ultérieur, plusieurs stratégies ont été proposées pour réduire les teneurs en oxygène et en acides, comme l'ajout d'un lit catalytique après la pyrolyse. La conversion catalytique des vapeurs de pyrolyse permet une désoxygénation partielle avant la condensation des vapeurs. Dans ce contexte, nous avons étudié la conversion de molécules modèles, l'acide acétique et le gaïacol, sur différents catalyseurs acides afin d'identifier des phases actives performantes et de comprendre les mécanismes réactionnels. Dans un deuxième temps, un test de pyrolyse semi-continu combiné avec un réacteur catalytique a été conçu et mis en place et les meilleurs catalyseurs acides sélectionnés pour les molécules modèles ont été testés pour la conversion de bois de hêtre. Après conversion, un protocole de séparation des fractions a été appliqué et les fractions gaz, liquide et solide ont été caractérisées par différentes méthodes (?-GC, GC×GC, GPC, RMN…). Une attention particulière a été portée à la quantification des monomères dans la fraction liquide par GC×GC. Les bilans massiques atteignent plus de 90% et des bilans carbones ont été également réalisés dans les différentes fractions. L'ensemble des caractérisations et la comparaison entre pyrolyse avec et sans étape catalytique permet d'améliorer la compréhension du rôle du catalyseur dans la conversion des vapeurs de pyrolyse / Fast pyrolysis of biomass yields bio-oils with high levels of oxygen-containing components, high acidity and low stability. Further upgrading of these oils is necessary before they can be used as liquid fuels. Several low-cost strategies have been proposed for reducing the oxygen and acid contents including the catalytic conversion of pyrolytic vapors before vapor condensation. In this context, a first step in this work was the study of model molecules conversion, acetic acid and guaiacol, on different acid catalyst to understand reaction mechanisms and determine the best catalyst. In a second time, a semi-continuous pyrolysis test combined with a catalytic reactor was built and use to test the best acid catalysts found on model molecules, for the conversion of beech wood chips. A product recovery protocol was implanted to recover all the gas, liquid and solid fractions. Those fractions were characterized in depth by various techniques (?-GC, GC×GC, GPC, RMN…). A special focus was made on the quantification of monomers in the bio-oils by GC×GC. Mass balance reached 90% and carbon balance were established for some experiments. The performed characterizations as well as the comparison between catalytic and thermal experiments allowed to get more insights in the role of the catalyst on pyrolytic vapors conversion