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Two Essays in Economics and Finance
Get PDFThis dissertation contains two essays. The first essay investigates the measure of FX liquidity and determinants of the change in FX liquidity. Using 20 cross currency exchange rates over spanning period of 1999 to 2016, funding constraints and global risks are responsible for the main drivers of changing in FX liquidity. The magnitudes of both G7 and emerging volatility index are offsetting each other in all the regression models indicating that FX investors take diversification trading strategies to diversify their portfolios. The financial crisis provides an evidence that the more financial constraint issues contribute to the change in FX market illiquidity more than non-financial crisis period. Extending to liquidity predictability, I find, however, that the lag of market FX liquidity is responsible for the change in FX liquidity than any other explanatory variables
My second essay investigates the momentum returns of U.S. equities by presenting comprehensive approaches. Traditionally, momentum portfolios are constructed by ranking based on excess returns. Using this sorting technique, I confirm that there is a presence of momentum returns in U.S. equities for all of the 48 industries. The results also indicate that the portfolios that are sorted by idiosyncratic volatility as well as by diversification strategy cannot achieve the highest returns as for sorting based on excess returns. Further, I examine the momentum portfolio predictability using the inverse conditional volatility proposed by Moreira and Muir (2017), and show that the momentum returns are affected by the size of liquidity and the risk factors rather than by the economic variables
II-VI Semiconductor Nanowire Array Sensors Based on Piezotronic, Piezo-Phototronic and Piezo-Photo-Magnetotronic Effects
Get PDFWith the rapid progress of nanotechnologies, there are two developing trends for the next generation of sensors: miniaturization and multi-functionality. Device miniaturization requires less power consumption, or even self-powered system. Multi-functional devices are usually based on multi-property coupling effects. Piezoelectric semiconductors have been considered to be potential candidates for self-powered/multi-functional devices due to their piezotronic coupling effect. In this dissertation, ZnO and CdSe nanowire arrays have been synthesized as the piezoelectric semiconductor materials to develop the following self-powered/multi-functional sensors: (1) self-powered gas sensors of ZnO/SnO2, ZnO/In2O3, ZnO/WO3 and CdSe nanowire arrays have been assembled. All these gas sensors are capable of detecting oxidizing gas and reducing gas without any external power supply owing to piezotronic effect which can convert mechanical energies to electrical energy to power the sensors; (2) a self-powered ZnO/ZnSe core/shell nanowire array photodetector has been fabricated. This photodetector is able to detect the entire range of the visible spectrum as well as UV light because of its type II heterostructure. The absolute sensitivity and the percentage change in responsivity of the photodetector were significantly enhanced resulting from the piezo-phototronic effect. The photodetector also exhibited self-powered photodetection behavior; (3) three dimensional nanowire arrays, such as ZnO and ZnO/Co3O4, have been synthesized to investigate piezo-magnetotronic and piezo-photo-magnetotronic effects. Under magnetic field, the magnetic-induced current of ZnO nanowire array decreased as magnetic field increased, and the current difference was magnified by one order of magnitude caused by piezo-magnetotronic effect through applying a stress. In contrast, under UV light illumination, the current response increased with an increment of magnetic field. The current difference was enhanced by at least two orders of magnitude attributed to piezo-photo-magnetotronic effect. Furthermore, ZnO/Co3O4 core/shell structure was employed to further improve the magnetic-induced current difference. This phenomenon projects a potential for multi-functional piezo-magnetotronic and piezo-photo-magnetotronic device development
Estudio Sobre Retrato del Templo de Selomo
Get PDFEn este artículo estudio la vida y uno de los libros del prestigioso intelectual y artista Jacob Judah (Aryeh) León (Siglo XVII), en el que describe el Templo de “Selomo.”[1] Nótese que el nombre del autor aparece en la portada de su libro: Retrato del Templo de Selomo, 1642 como: Jacobo Judah León.[2] Al final de su vida se le comenzó a llamar Templo por su famosa maqueta del Templo. Asimismo, sus hijos adoptaron Templo como el nombre de la familia
Preface to Habsburg’s Last War: The Filmic Memory (1918 to the Present)
Get PDFhttps://scholarworks.uno.edu/hlw/1001/thumbnail.jp
World War I in Hungarian Motion Picture History, 1914 to 1945
Get PDFhttps://scholarworks.uno.edu/hlw/1007/thumbnail.jp
The Decaying Empire and the Human Dilemmas: The Last War of Austria-Hungary in Polish Cinematography from 1918 Onwards
Get PDFhttps://scholarworks.uno.edu/hlw/1010/thumbnail.jp
Platinum@Hexaniobate Nanopeapods: Sensitized Composite Architectures for Photocatalytic Hydrogen Evolution Under Visible Light Irradiation
Get PDFHydrogen fuel is one of the most important areas of research in the field of renewable energy development and production. Hydrogen gas can be generated by fuel cells, water electrolyzers, and heterogeneous nanoscale catalysts. It can be burned to directly release chemical energy or condensed for storage and transport, providing fuel for combustion devices or storing excess energy generated by renewable sources such as wind turbines and concentrated solar power assemblies. While platinum is the most active catalyst for hydrogen reduction, its high cost significantly deters its utilization in advanced photocatalytic materials. One approach to mitigating this expense is optimizing the morphology and placement of nanostructured platinum catalysts. Highly crystalline, morphologically-controlled platinum nanoparticles (Pt NPs) have been effectively utilized to increase hydrogen generation efficiency in a variety of nanocomposite materials. However, synthesis routes to high-quality Pt NPs can be dangerous and difficult to replicate. Furthermore, utilization of the Pt NPs in nanocomposite materials is hindered by lack of control over catalyst placement.
Nanopeapods are versatile nanocomposites that offer a high degree of control over catalyst placement as well as the potential for interesting new properties arising from the interaction between the catalyst and a semiconductor. Platinum@hexaniobate nanopeapods (Pt@HNB NPPs) consist of linear arrays of Pt NPs encapsulated within the scrolled semiconductor hexaniobate. Pt@HNB NPPs offer significant advantages over similar composites by utilizing the isolated reduction environment of the encapsulated Pt NP arrays to decrease kinetic competition and surface crowding.
This work describes the design, fabrication, and implementation of the new nanocomposite platinum@hexaniobate nanopeapods for sensitized hydrogen production under visible light irradiation. The following chapters present facile microwave heating syntheses of highly crystalline Pt nanocubes and Pt@HNB NPPs with consistent morphology and high catalyst loading. A detailed study is also presented of the optical properties of the Pt nanocubes, which produced a UV-range absorbance band that indicates the formation of a localized surface plasmon resonance. Most significantly, preliminary results from visible light photolysis indicate that sensitized Pt@HNB NPPs produce hydrogen in quantities comparable to published systems, and that alteration of experimental parameters may result in even greater yields
Sefaradíes: El Deseo de Mantener la Lengua y la Identidad -Testimonios: Cervantes, Croce, Caro Baroja
No full textUnderstanding the impacts of current and future environmental variation on central African amphibian biodiversity
Get PDFGlobal climate change is projected to impact multiple levels of biodiversity by imposing strong selection pressures on existing populations, triggering shifts in species distributions, and reorganizing entire communities. The Lower Guineo-Congolian region in central Africa, a reservoir for amphibian diversity, is predicted to be severely affected by future climate change through rising temperatures and greater variability in rainfall. Geospatial modelling can be used to assess how environmental variation shapes patterns of biological variation – from the genomic to the community level – and use these associations to predict patterns of biological change across space and time. The overall goal of this dissertation is to examine potential impacts of climate change on amphibian diversity in central Africa. Geospatial modeling is used to: 1) map the distribution of the amphibian fungal pathogen, Batrachochytrium dendrobatidis (Bd) in a biodiversity hotspot in Cameroon under current and future climate; 2) assess phenotypic and adaptive genomic variation in a widespread frog species, Phrynobatrachus auritus, in order to predict areas where populations may best adapt under climate change; 3) determine how amphibian community composition may shift with climate change and which areas may experience greatest loss of functional groups. Findings show that most Bd samples belong to a globally hypervirulent lineage. However, areas of highest predicted environmental suitability for Bd are predicted to shrink under warming temperatures. Within P. auritus, most phenotypic and genomic turnover occurred across known ecological gradients and are heavily influenced by seasonal precipitation. Current amphibian beta diversity is greatest throughout the Cameroonian highlands and forest-savanna ecotones flanking the central Congolian lowland forests. Greatest shifts in community composition under climate change are predicted to occur in coastal Cameroon and its eastern border whereas the greatest predicted loss of functional richness was in central Gabon. Overall, this dissertation shows that areas of elevated environmentally-associated phenotypic, genomic, and community turnover are associated with key ecological gradients. Regions predicted to experience high genomic mismatch, large shifts in community composition, and high loss of functional richness resulting from climate change may warrant conservation attention
Impact of Labor Protection Laws on the Operating and Financial Risks of Firms: The Case of China
Get PDFA debate exists regarding the effect of labor protection laws on labor costs. Whether labor protection laws increase or decrease labor costs has implications for risk exposure of affected firms. If the labor costs go up, all else the same, the firm’s breakeven point goes up. Facing increased business risk, the firm must resort to strategies that inhibit the risk exposure, especially if the higher labor costs cannot be transferred, without adverse consequences, to consumers. The strategies include reigning in, if at all possible, operating leverage and financial leverage. Conversely, if the labor costs decrease, a firm’s business risk declines, and the firm has options to increase its operating leverage and/or financial leverage, lower the product price, or do nothing. By examining the Chinese firms’ reactions to the 2007 labor protection laws, we draw conclusions about laws’ directional impact on labor costs. We find that Chinese firms attempt to reduce business risk by lessening labor intensity, and labor-intensive firms are able to reduce the labor intensity at a significantly higher rate than capital-intensive firms. Neither group is able to significantly reduce asset tangibility. We also find that all firms significantly reduce their financial leverages. Consequently, firms’ investments, as measured by sales growth, decline in the post-reform period. These results are consistent with the cost of labor increasing as a result of the stricter labor protection laws