MODELING HYDROGEN FUEL OPERATION OF A GAS TURBINE ENGINE

This research utilized a computational fluid dynamics (CFD) software and a thermodynamic cycle modeling software package to model the operation of a 30 kW micro gas turbine engine combustion chamber using hydrogen fuel. With increasing importance of energy resilience and security in the maritime environment, hydrogen provides a unique solution to energy storage and production challenges when paired with gas turbine engines. The combustion chamber was modeled at three different loading conditions using CFD and the results were compared to the gas turbine cycle models created, experimental data taken from the engine, and another CFD model using propane fuel. The project provides insight on flame development, surface temperatures, efficiencies, mesh sensitivity, and transient behavior of the flow during hydrogen fuel operation and gives recommendations for design considerations and future investigations.Distribution Statement A. Approved for public release: Distribution is unlimited.Ensign, United States NavyOffice of Naval Research, Arlington VA, 2220

El Arte como Medio para Facilitar el Bilingüismo y Biculturalismo: Sugerencias desde una Revisión de la Literatura

This review of the literature critically explores the avenues to learning that visual art offers teachers and especially those with second language learners in their classrooms. The article is divided into seven sections in which the authors present research findings supporting the premise that learners’ cognitive processes are facilitated by images. Research cited strongly suggests visual art in instructional design helps students learn about world cultures, is an effective pre-writing activity, facilitates second language acquisition, and promotes biliteracy.Esta revisión de la literatura explora críticamente los caminos al aprendizaje que el arte visual provee a  los maestros,  especialmente a  los que tienen estudiantes que están aprendiendo  un segundo idioma en sus aulas. El artículo está dividido en siete secciones, en las cuales el autor presenta resultados de investigaciones previas que apoyan la premisa de que las imágenes visuales facilitan los procesos cognitivos de los estudiantes.  Las investigaciones citadas indican claramente que a los estudiantes les beneficia  dibujar e involucrarse en actividades visuales antes de redactar,  lo cual facilita la adquisición de un segundo idioma y  promueve  la alfabetización en la primera y segunda lengua

Fluid-rock interaction during high-grade metamorphism: instructive examples from the Southern Marginal Zone of the Limpopo Complex, South Africa

The Southern Marginal Zone of the Limpopo Complex documents strong evidence that CO2-rich (XCO2=0.7–0.9, XH2O= 0.1–0.3) and brine fluids of greatly reduced water activity interacted with cooling metapelitic granulite during the thrust-controlled emplacement at 2.69–2.62 Ga onto the granite-greenstone terrain of the northern Kaapvaal Craton. Interaction of cooling metapelitic granulite with CO2-rich fluids at T 900°C, P > 7.5 kbar. Interaction of hot melt with metapelitic granulite continued until final emplacement in the middle crust (P = 6 kbar, T = 630°C). Brine fluids also initiated shear zone-hosted metasomatism of quartzo-feldspathic gneisses at T between 600 and 900°C and amphibolite-facies lode-gold mineralization. Available data implicate devolatilization of underthrusted greenstone material as the dominant deep crustal source for infiltrating CO2-rich and brine fluids

A Method to Determine the In-Air Spatial Spread of Clinical Electron Beams

We propose and analyze in detail a method to measure the in-air spatial spread parameter of clinical electron beams. Measurements are performed at the center of the beam and below the adjustable collimators sited in asymmetrical configuration in order to avoid the distortions due to the presence of the applicator. The main advantage of our procedure lies in the fact that the dose profiles are fitted by means of a function which includes, additionally to the Gaussian step usually considered, a background which takes care of the dose produced by different mechanisms that the Gaussian model does not account for. As a result, the spatial spread is obtained directly from the fitting procedure and the accuracy permits a good determination of the angular spread. The way the analysis is done is alternative to that followed by the usual methods based on the evaluation of the penumbra width. Besides, the spatial spread found shows the quadratic-cubic dependence with the distance to the source predicted by the Fermi-Eyges theory. However, the corresponding values obtained for the scattering power are differing from those quoted by ICRU nr. 35 by a factor ~2 or larger, what requires of a more detailed investigation.Comment: 11 pages, 5 Postscript figures, to be published in Medical Physic

Overview of the facility accident analysis for the U.S. Department of Energy Environmental Restoration and Waste Management Programmatic Environmental Impact Statement

An integrated risk-based approach has been developed to address the human health risks of radiological and chemical releases from potential facility accidents in support of the U.S. Department of Energy (DOE) Environmental Restoration and Waste Management (EM) Programmatic Environmental Impact Statement (PEIS). Accordingly, the facility accident analysis has been developed to allow risk-based comparisons of EM PEIS strategies for consolidating the storage and treatment of wastes at different sites throughout the country. The analysis has also been developed in accordance with the latest DOE guidance by considering the spectrum of accident scenarios that could occur in implementing the various actions evaluated in the EM PEIS. The individual waste storage and treatment operations and inventories at each site are specified by the functional requirements defined for each waste management alternative to be evaluated. For each alternative, the accident analysis determines the risk-dominant accident sequences and derives the source terms from the associated releases. This information is then used to perform health effects and risk calculations that are used to evaluate the various alternatives

Determination of Porphyrins in Bile Using High Performance Liquid Chromatography and Some Clinical Applications

Peer Reviewe