Chemical Engineering Commons^™

Fast Measurements Of Flow Through Mitral Regurgitant Orifices With Magnetic Resonance Phase Velocity Mapping, Haosen Zhang, Sandra S. Halliburton, Richard D. White, George P. Chatzimavroudis

Chemical & Biomedical Engineering Faculty Publications

Magnetic-resonance (MR) phase velocity mapping (PVM) shows promise in measuring the mitral regurgitant volume. However, in its conventional nonsegmented form, MR-PVM is slow and impractical for clinical use. The aim of this study was to evaluate the accuracy of rapid, segmented k-spaceMR-PVM in quantifying the mitral regurgitant flow through a control volume (CV) method. Two segmented MR-PVM schemes, one with seven (seg-7) and one with nine (seg-9) lines per segment, were evaluated in acrylic regurgitant mitral valve models under steady and pulsatile flow. A nonsegmented (nonseg) MR-PVM acquisition was also performed for reference. The segmented acquisitions were …

Design And Simulation Of An Induction Skull Melting System, Taide Tan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Incorporating volatile actinides, mainly americium into a metallic fuel pin (MFP) has been a serious problem due to americium’s high vapor pressure. An Induction Skull Melting (ISM) system was identified by Argonne National Laboratory (ANL) as a potential furnace design to cast MFPs. Through the development of the ISM system, the nuclear waste feedstock can be melted and injected into the mold for fabricating MFPs in the advanced nuclear fuel cycles. The main phenomena in this system include: induction melting process, casting process and mass transfer process of americium. Issues related to ISM system design for casting MFPs are discussed …

A Rapidly-Converging Alternative To Source Iteration For Solving The Discrete Ordinates Radiation Transport Equations In Slab Geometry, Nicholas J. Wager

Theses and Dissertations

I present a numerical technique to solve the time independent Boltzmann Transport Equation for the transport of neutrons and photons. The technique efficiently solves the discrete ordinates equations with a new iteration scheme. I call this new scheme the angle space distribution iteration method because it combines a non-linear, high angular-resolution flux approximation within individual spatial cells with a coarse angular-resolution flux approximation that couples all cells in a spatial mesh. This shown to be an efficient alternative to source iteration. The new method is implemented using the step characteristic and exponential characteristic spatial quadrature schemes. The latter was introduced …

Magnetophoresis Of Nonmagnetic, Submicrometer Particles In Magnetic Fluids, Seif-Eddeen K. Fateen

Seif-Eddeen K Fateen

No abstract provided.

Dynamics Of Two-Phase Reactors With Approximate Kinetics, Francisco J. Valdes-Parada

Francisco J. Valdes-Parada

Los sistemas de transporte y reacción en más de una fase han ido adquiriendo un interés creciente en la comunidad científica y tecnológica debido a que la gran mayoría de los procesos industriales se llevan a cabo en sistemas no homogéneos. De la misma forma, es notable el interés que se ha dado en las últimas décadas por los sistemas catalizados por enzimas.

Las enzimas como catalizadores son utilizadas actualmente en una gran variedad de procesos, como son la fabricación de etanol, insulina, ácido láctico, cerveza, vacunas, entre muchos otros; de hecho varias procesos clásicos han sido reemplazados por procesos …

Teaching Coupled Transport And Rate Processes, Yaşar Demirel

Department of Chemical and Biomolecular Engineering: News Releases

Coupling refers to a flux occurring without its primary thermodynamic driving force; for example, mass flux without a concentration gradient called the thermal diffusion is a well-known coupled process. Coupling also refers to a flux occurring in a direction opposite to the direction imposed by its driving force; for example, a mass flux can occur from a low to a high concentration region and is called the active transport or uphill transport, such as potassium and sodium pumps coupled to chemical energy released by the hydrolysis of adenosine triphosphate (ATP) in biological systems. Although the coupled processes seem to be …

A Steady-State Impedance Model For A Pemfc Cathode, Qingzhi Guo, Ralph E. White

Faculty Publications

A model for the simulation of the steady-state impedance response of a polymer electrolyte membrane fuel cell (PEMFC) cathode is presented. The catalyst layer of the electrode is assumed to consist of many flooded spherical agglomerate particles surrounded by a small volume fraction of gas pores. Stefan-Maxwell equations are used to describe the multicomponent gas-phase transport occurring in both the gas diffusion layer and the catalyst layer of the electrode. Liquid-phase diffusion of O2 is assumed to take place in the flooded agglomerate particles. Newman’s porous electrode theory is applied to determine over-potential distributions. © 2004 The Electrochemical Society. All …

Teaching Coupled Transport And Rate Processes, Yasar Demirel

YASAR DEMIREL

Coupling refers to a flux occurring without its primary thermodynamic driving force; for example, mass flux without a concentration gradient called the thermal diffusion is a well-known coupled process. Coupling also refers to a flux occurring in a direction opposite to the direction imposed by its driving force; for example, a mass flux can occur from a low to a high concentration region and is called the active transport or uphill transport, such as potassium and sodium pumps coupled to chemical energy released by the hydrolysis of adenosine triphosphate (ATP) in biological systems.

Exergy-Based Performance Analysis Of Packed-Bed Solar Air Heaters, Yasar Demirel, H.H. Ozturk

YASAR DEMIREL

This paper presents an experimental investigation of the thermal performance of a solar air heater having its flow channel packed with Raschig rings. The packing improves the heat transfer from the plate to the air flow underneath. The dimensions of the heater are 0.9m wide and 1.9m long. The aluminium-based absorber plate was coated with ordinary black paint. The characteristic diameter of the Raschig rings, made of black polyvinyl chloride (PVC) tube, is 50mm and the depth of the packed-bed in flow channel is 60 mm. Energy and exergy analyses were applied for evaluating the efficiency of the packed-bed solar …