934 resultados para the parabolized stability equations (PSE)


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In this paper we explore the possibility of using the equations of a well known compact model for CMOS transistors as a parameterized compact model for a variety of FET based nano-technology devices. This can turn out to be a practical preliminary solution for system level architectural researchers, who could simulate behaviourally large scale systems, while more physically based models become available for each new device. We have used a four parameter version of the EKV model equations and verified that fitting errors are similar to those when using them for standard CMOS FET transistors. The model has been used for fitting measured data from three types of FET nano-technology devices obeying different physics, for different fabrication steps, and under different programming conditions. © 2009 IEEE NANO Organizers.

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Corn starch, gelatin, sago palm starch, agar, and bread flour were tested for their binding capacity in pelleted diets for Penaeus monodon . Agar was found to be good binder, but it costs too much, while bread flour was also good but as it's commonly used for human comsumption its use for animal feed should be minimized. The use of 20% bread flour, or a combination of 5% sago palm starch or corn starch with 15% bread flour is recommended, depending on the cost and availability. Basic composition of the formulated diet is tabulated, as is water stability of 2 and 4 mm diameter steamed pellets after 2, 6 and 18 h.

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A study was conducted to determine the comparative effectiveness of purified, semipurified and crude starch of sago as binders for pelleted shrimp diets. The diet containing semipurified sago starch had the highest water stability (79.1%). The values were nearly the same for the pellets bound with purified and crude sago starch. Reasons for the low binding capacity of purified and crude sago could be that the gel of purified sago is weakened due to purification, and that of the crude sago is due to the spongy material present in the product. Thus, semipurified sago starch is a better source of binder and purified crude sago. From the economic viewpoint, the cost of purified sago is prohibitive for use as binder. Both semipurified and crude sago palm starch are acceptable. Composition of shrimp diets containing various sources of sago palm starch, and binder cost and water stability of shrimp diets containing various sources of sago palm starch tested at 3, 6 and 12 hours, are tabulated.

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The water stability of shrimp (Penaeus monodon) diets with various polysaccharides as binding agents were tested without steaming. The diet with alginate showed the best water stability and did not completely disintegrate in 24 hours. However, the use of alginate is dependent on cost and availability, so alternate choices may be a combination of sago palm starch and wheat flour or glutinous rice flour.

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This paper describes a derivation of the adjoint low Mach number equations and their implementation and validation within a global mode solver. The advantage of using the low Mach number equations and their adjoints is that they are appropriate for flows with variable density, such as flames, but do not require resolution of acoustic waves. Two versions of the adjoint are implemented and assessed: a discrete-adjoint and a continuous-adjoint. The most unstable global mode calculated with the discrete-adjoint has exactly the same eigenvalue as the corresponding direct global mode but contains numerical artifacts near the inlet. The most unstable global mode calculated with the continuous-adjoint has no numerical artifacts but a slightly different eigenvalue. The eigenvalues converge, however, as the timestep reduces. Apart from the numerical artifacts, the mode shapes are very similar, which supports the expectation that they are otherwise equivalent. The continuous-adjoint requires less resolution and usually converges more quickly than the discrete-adjoint but is more challenging to implement. Finally, the direct and adjoint global modes are combined in order to calculate the wavemaker region of a low density jet. © 2011 Elsevier Inc.

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We report the effects of thermal annealing performed in N2 or O2 ambient at 1200 °C on the structural and optical properties of Er silicate films having different compositions (Er2Si O 5,Er2 Si2 O7, and their mixture). We demonstrate that the chemical composition of the stoichiometric films is preserved after the thermal treatments. All different crystalline structures formed after the thermal annealing are identified. Thermal treatments in O 2 lead to a strong enhancement of the photoluminescence intensity, owing to the efficient reduction of defect density. In particular the highest optical efficiency is associated to Er ions in the α phase of Er 2 Si2 O7. © 2008 American Institute of Physics.

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The stability of the excellent permanent magnetic compound Nd2Fe14B and substitution of Fe in the compound by V, Cr, Mn, Zr and Nb are investigated by using interatomic pair potentials which are converted from lattice-inversion method. Calculation shows that the substitution always makes the cell volume larger, and the increase of the volume is almost linear with substituent concentration. The calculated cohesive energy shows that the preferential order of substitution of Fe is Nb, V, Cr, Mn, Zr. Nevertheless, all the five substituting elements should most preferentially replace Fe in the j(2)' site, which has the greatest space among all six Fe sites. (C) 2005 Elsevier B.V. All rights reserved.

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The thermal stability of InN in the growth environment in metalorganic chemical vapor deposition was systematically investigated in situ by laser reflectance system and ex situ by morphology characterization, X-ray diffraction and X-ray photoelectron spectroscopy. It was found that InN can withstand isothermal annealing at temperature as high as 600 degrees C in NH3 ambient. While in N-2 atmosphere, it will decompose quickly to form In-droplets at least at the temperature around 500 degrees C, and the activation energy of InN decomposition was estimated to be 2.1 +/- 0.1 eV. Thermal stability of InN when annealing in NH3 ambient during temperature altering would be very sensitive to ramping rate and NH3 flow rate, and InN would sustain annealing process at small ramping rate and sufficient supply of reactive nitrogen radicals. Whereas In-droplets formation was found to be the most frequently encountered phenomenon concerning InN decomposition, annealing window for conditions free of In-droplets was worked out and possible reasons related are discussed. In addition, InN will decompose in a uniform way in the annealing window, and the decomposition rate was found to be in the range of 50 and 100 nm/h. Hall measurement shows that annealing treatment in such window will improve the electrical properties of InN. (c) 2005 Elsevier B.V. All rights reserved.

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To investigate the effect of radiation damage on the stability and the compressive stress of cubic boron nitride (c-BN) thin films, c-BN films with various crystalline qualities prepared by dual beam ion assisted deposition were irradiated at room temperature with 300 keV Ar+ ions over a large fluence range up to 2 x 10(16) cm(-2). Fourier transform infrared spectroscopy (FTIR) data were taken before and after each irradiation step. The results show that the c-BN films with high crystallinity are significantly more resistant against medium-energy bombardment than those of lower crystalline quality. However, even for pure c-BN films without any sp(2)-bonded BN, there is a mechanism present, which causes the transformation from pure c-BN to h-BN or to an amorphous BN phase. Additional high resolution transmission electron microscopy (HRTEM) results support the conclusion from the FTIR data. For c-BN films with thickness smaller than the projected range of the bombarding Ar ions, complete stress relaxation was found for ion fluences approaching 4 x 10(15) cm(-2). This relaxation is accompanied, however, by a significant increase of the width of c-BN FTIR TO-line. This observation points to a build-up of disorder and/or a decreasing average grain size due to the bombardment. (c) 2005 Elsevier B.V. All rights reserved.