The total dose radiation response of nitrided and nonnitrided n-type 4H-SiC is reported for metal oxide semiconductor capacitors exposed to 10-keV X-rays under positive bias. The radiation response is affected strongl...
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Intrinsic Optical Signal (IOS) imaging is a widely accepted technique for imaging brain activity. We propose an integrated device consisting of interleaved arrays of gallium arsenide (GaAs) based semiconductor light s...
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A number of research groups and companies have succeeded in employing various SLS schemes to create low defect-density Si films on glass substrates for making high performance TFTs, In this paper, we first point out t...
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A number of research groups and companies have succeeded in employing various SLS schemes to create low defect-density Si films on glass substrates for making high performance TFTs, In this paper, we first point out that SLS can be utilized to just as effectively handle crystallization of thin Si films on polymer substrates, and then present preliminary results on high-performance circuits that are built using the materials.
The magnetization of single crystal Gd5Ge4, which in a zero magnetic field orders antiferromagnetically at 128K, indicates a reversible spin-flop transition when the magnetic field is along the c axis and the absence ...
The magnetization of single crystal Gd5Ge4, which in a zero magnetic field orders antiferromagnetically at 128K, indicates a reversible spin-flop transition when the magnetic field is along the c axis and the absence of similar transformations when the magnetic field vector is perpendicular to the c axis. This anisotropic behavior is due to variation of magnetization energy between the c axis and the a or b axes of the orthorhombic crystal caused by a different alignment of the Gd moments with respect to the magnetic field vector. The anisotropy of the antiferromagnetic state diminishes with the increasing magnetic field and temperature. The critical magnetic field for the antiferromagnetic-ferromagnetic transition is the smallest and the ferromagnetic state is most stable when the magnetic field vector is parallel to the b axis, indicating an easy magnetization direction along this axis. The anisotropy of the magnetic field-induced transformation in Gd5Ge4 is discussed in connection with the coupled magnetic and structural transitions. Anisotropic magnetic phase diagrams along the three major crystallographic axes are constructed.
Probe microscopes are key tools for surface characterization and nanoscale science. This category of instrumentation has enabled researchers both to investigate properties and to manipulate materials at the nanoscale....
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The inverted-pendulum method of thrust measurement for high-power electric thrusters is described analytically and experimentally. Two sources of uncertainty in the thrust measurements are investigated: those due to c...
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ISBN:
(纸本)1563478188
The inverted-pendulum method of thrust measurement for high-power electric thrusters is described analytically and experimentally. Two sources of uncertainty in the thrust measurements are investigated: those due to changes in the sensitivity of the inverted pendulum and those due to tare forces resulting from thermal stresses and electromagnetic forces acting on the flexural elements. An idealized analytical model shows that changes in sensitivity occur due to changes in the mass loading of the inverted pendulum and the temperature of the flexure elements. The sensitivity can be increased only at the expense of more stringent requirements on mass loading and thermal control. The results of the model are validated with measurements made using a carefully calibrated inverted pendulum thrust stand having several advantageous design features including gallium pots for current conduction, an optical two-axis displacement sensor, and careful consideration of flexure shape and cooling requirements. The sensitivity is shown to be constant over a wide range of operating conditions. Measurements show that thermal drifts of the stand are linear on the time scale of the thrust measurements and are less than 0.6% of the expected thrust. The thrust stand operation was demonstrated during experiments with a 30-kW lithium-fed applied-field magnetoplasmadynamic thruster. Under nominal conditions (400 A, 0.1 T, 17.5 mg/s) the thermal and electromagnetic tare forces were measured at less than 9% of the thrust and the total thrust uncertainty at ≤ 10% of the thrust.
Absorption-scaling methods were applied to Monte Carlo simulations of two-layered tissues by incorporating a path integral (PI) formalism. Times spent by photons in the top-layer can be significantly underestimated wh...
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Electron correlation effects on the electronic structure of Gd5Si2Ge2 have been studied using the tight binding linear muffin-tin orbital method within the framework of the local spin density approximation with the Co...
Electron correlation effects on the electronic structure of Gd5Si2Ge2 have been studied using the tight binding linear muffin-tin orbital method within the framework of the local spin density approximation with the Coulomb correlation parameter approach. The magnetostructural transition temperature (TM) and the magnetocaloric effect (isothermal magnetic entropy change, ΔSM) have been calculated using this method by applying the scalar relativistic band theory and the nonlocal exchange correlation parametrization of the exchange correlation potential together with a magnetothermodynamic model. Both TM and ΔSM are in good agreement with experimental values.
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