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Full-Text Articles in Engineering
An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider
An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider
Dissertations and Theses
Since the need of energy conservation has become more and more urgent in the past decades, there has been an increased interest in the study and development of more efficient energy conversion systems. One of the fields that have arisen from that endeavor is a branch of physics called Finite Time Thermodynamics (FIT). It may be said that FIT was initiated through the famous paper by Curzon and Ahlborn (1975) that established new bounds on the efficiency of a finite time Carnot heat engine. Before, the traditional treatments gave a fundamental upper limit on the efficiency of any heat engine. …
Inhibited Spontaneous Emission By Photonic Band Gaps In A Square Lattice Of Periodic Dielectric Medium, Abdullah Al-Ghamdi
Inhibited Spontaneous Emission By Photonic Band Gaps In A Square Lattice Of Periodic Dielectric Medium, Abdullah Al-Ghamdi
Masters Theses
The concepts of band theory for electrons can be employed to describe the behavior of electromagnetic waves propagating in two-dimensional, periodic dielectric structures. These two-dimensional, periodic structures can produce photonic band gaps in which the spontaneous emission by atoms embedded in the structure is prohibited and as a result the performance of many semiconductor devices can be enhanced. The calculations are based on finding the eigenvalues of the algebraic equation for the frequencies of electromagnetic waves moving in a square lattice composed of square dielectric rods with different dielectric constants.
On Shock Capturing For Liquid And Gas Media, Tze Jang Chen
On Shock Capturing For Liquid And Gas Media, Tze Jang Chen
Mathematics & Statistics Theses & Dissertations
The numerical investigation of shock phenomena in gas or liquid media where a specifying relation for internal energy is absent poses special problems. Classically, for gas dynamics the usual procedure is to employ a splitting scheme to remove the source terms from the Euler equations, then up-wind biased shock capturing algorithms are built around the Riemann problem for the system which remains. However, in the case where the Euler equations are formulated in the term of total enthalpy, a technical difficulty associated with equation splitting forces a pressure time derivative to be treated as a source term. This makes it …
Magnetic Field Strength Of Toroidal Plasma Equilibria, David Alan Garren
Magnetic Field Strength Of Toroidal Plasma Equilibria, David Alan Garren
Dissertations, Theses, and Masters Projects
The goal of nuclear fusion research is to confine a deuterium-tritium plasma at a sufficiently high temperature (15 keV) and density (3 $\times$ 10$\sp{20}$ m$\sp{-3}$) for a sufficient length of time (1 sec) to produce net fusion power. One means to attain the required plasma confinement is to embed the plasma within a magnetic field. The global structure of this magnetic field determines the variation of magnetic field strength within the surfaces of constant plasma pressure. This field strength variation in turn determines many of the stability and confinement properties of the plasma. This dissertation gives the first detailed exposition …
Nuclear Magnetic Resonance Studies Of Amorphous Nickel-Zirconium Hydrides, Harris Clarence Hoke Jr.
Nuclear Magnetic Resonance Studies Of Amorphous Nickel-Zirconium Hydrides, Harris Clarence Hoke Jr.
Dissertations, Theses, and Masters Projects
This research deals with one aspect of the scientific field of hydrogen in metals. The study of hydrogen in metals is technologically important for many reasons, among them is the use of hydrogen in metals to store energy. Hydrogen related energy technology is particularly attractive because hydrogen can be extracted from water, our most abundant resource, and can be used without any pollution. Metal hydrides may one day be widely used for automotive propulsion in cars, in batteries, and many other energy conversion devices. Amorphous NiZr is particularly interesting for hydrogen storage because high concentrations of hydrogen can be sorbed …