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Showing 1 to 20 of 250 for “"Ohmic"”.
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Computational Studies of Ohmic Heating in the Spheromak
… for and utilized in an investigation of the ohmic heating of a spheromak plasma. The plasma density and composition, the applied magnetic field strength, the plasma size, and the plasma current density profile are considered for their effects on the spheromak heating rate and maximum …
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Nano-scale ohmic contacts for III-V MOSFETs
… it is necessary to fabricate source and drain ohmic contacts with ultra-low contact resistance, perhaps as low as 50 [Omega] · [mu]m. This is particularly difficult to achieve as the device size shrinks down to the 10-20 nm length range since the contact resistance increases drastically for …
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Method of Measuring Ohmic Resistance in Aluminium Reduction Cells
… to develop a method of directly measuring the ohmic resistance in an industrial aluminium reduction cell. This requires that the voltage due to ohmic resistance be distinguished from the voltage due to the Nernst potential and polarisation. Electrochemical impedance spectroscopy can be used to …
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Ohmic Contacts to N -Type Gallium Nitride Based Semiconductors
… of electrical and materials performance of ohmic contacts are presented. Surface treatment techniques were developed to improve the electrical characteristics of ohmic contacts. Ti/Al/Mo/Au metallization scheme was developed to form ohmic contacts to n-GaN, n-AlxGa1-xN, and AlGaN/GaN HEMTs. …
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Analysis of Mo sidewall ohmic contacts to InGaAs fins
… a vertical nanowire field-effect-transistor, the Ohmic contact at the top of the nanowire not only covers the top surface, but also wraps around the sidewall. Because the sidewall is considered to be different from the top surface, it is necessary to study the sidewall Ohmic contact properties …
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A Schottky-to-Ohmic Transition in Epitaxial Ferroelectric Hafnia Devices
… a purely capacitive (Schottky) and resistive (Ohmic) state, a Schottky-to-Ohmic transition (SOT). A series of voltage pulse trains were used to explore the intermediate resistance states of the system. Both analog and integration behaviour was demonstrated, depending on the pulse profile. The …
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A Novel Temperature Control Method for Electrode Type Ohmic Water Heaters
… is to develop a temperature rise model for an Ohmic type electrode water heater, that regulates temperature by adjusting the electrode separation. The type and amount of dissolved solids and temperature, determine the electrical conductivity of the water, which limits the instantaneous power of …
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Modeling and Electrical Characterization of Ohmic Contacts on n-type GaN
… and device operation. The low resistance ohmic contacts for n-GaN have been well established while most p-GaN devices have still high contact resistivity. Significant work has not been found that focuses on software-based modeling of the device to analyze the contact resistance and …
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Foundations of Ohmic Contact Formation on Aluminum Gallium Nitride/gallium Nitride Heterostructures
… and mm power amplifications. Fabrication of Ohmic contacts for such devices that meet the stringent low-resistance, high thermal stability and smooth surface morphology requirements has been challenging. In the cases where Ohmic behavior can be achieved, a full scientific understanding of the …
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RF Ohmic MEMS Switches Utilizing Printed and Carbon Based Nanomaterials for Space Applications
… to the development of Radio Frequency (RF) Ohmic (metal-to-metal contact-type) MEMS (micro-electro-mechanical-systems) Switches for Space Applications. Ohmic contact devices void of any dielectric layer are considered exclusively in order to avoid the possibility of dielectric charging …
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Investigation of Ohmic Contacts for Gallium Nitride-Based Power Electronic Devices Using Molecular Beam Epitaxy
… and develop stable and reproducible low ohmic contacts through careful monitoring of the GaN surface and distribution of dopants while employing SAG by plasma assisted molecular beam epitaxy (PAMBE). The work specifically involved thin film growth, film characterization, device …
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Ohmic Metallizations to Aluminum Gallium Nitride/gallium Nitride High Electron Mobility Transistors: Electrical and Microstructural Studies
"Major findings of this work include: (1) Elucidated the interfacial reactions between Al, Ti, AlTi alloy, and Ti/Al/Mo/Au on GaN. (2) Explained the electrical performance of Ti/Al/Mo/Au on AlGaN/GaN based on microstructural investigations. Proposed a ""spike"" mechanism. (3) Identified the role of …
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A 12-bit 500 MHz GaAs MESFET digital-to-analog converter with p+ ohmic contact isolation
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1992.
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EXPERIMENTAL STUDIES OF QUANTUM OSCILLATIONS IN THE TRANSVERSE MAGNETORESISTANCE OF SINGLE-CRYSTALLINE, ULTRAPURE MAGNESIUM: NON-OHMIC EFFECTS.
We report here the observation of non-ohmic behavior in the dominant oscillatory component (the cigar component) of ρ('H) in ultrapure magnesium when the magnetic field, 'H, is parallel to [0001] and the current density, 'J, lies in the basal plane. In order to study this new phenomenon …
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Monolithic Integration of Thermally Stable Enhancement-Mode and Depletion-Mode Indium Phosphide HEMTs Utilizing Iridium-Gate and Silver-Ohmic Contact Techniques
Excellent ohmic contacts based on Ge/Ag/Ni metallization have been developed for InAlAs/InGaAs/InP high electron mobility transistors (HEMTs) in a temperature range between 385 and 500°C for the first time. A minimum contact resistance of 0.06 O-mm was obtained at an annealing temperature of …
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Hydromagnetic radiative effect on water, kerosene based on single walled carbon nanotubes induced by a stretching/shrinking sheet with viscous-ohmic dissipation
… of viscous dissipation, thermal radiation and Ohmic heating is investigated numerically.The similarity transformation reduces the time-independent boundary layer equations for continuity, momentum and energy into a set of coupled ordinary differential equations. The obtained governing equations …
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Experimental study of turbulent heat transport in Alcator C-Mod
… thesis work provided new information about the Ohmic confinement transition, from the linear to the saturated confinement regime with the increase in average density. It was found that Te fluctuations near the edge (r/a0~.85) tend to decrease across the Ohmic confinement transition. Although the …
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Probing Interfacial Potential under Transient Conditions via Second Harmonic Generation at Pt-water interface
… deviate from the applied potential due to the Ohmic resistance (the RC element in the circuit). However, characterizing this deviation has been challenging. In this thesis, an optical method based on second harmonic generation (SHG) spectroscopy is used to monitor the electrochemical potential …
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Rotation generation and transport in tokamak plasmas
… three aspects of rotation: momentum transport, Ohmic rotation reversals, and LHCD induced rotation. Momentum transport is approached in a semi-empirical method through the development of the "Toy Model." The "Toy Model" assumes that the toroidal momentum is transported via diffusive and …
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