Transforming projection methods to solve steady incompressible flows

Abstract

Projection methods are known to be very effective in solving the unsteady flow problems. In this study the idea used in the SIMPLEC method is used to derive the general three- and the four-step projection methods. The concept used in the derivation of the projection methods is extended to obtain projection type methods for the solution of the steady flow problems directly, without resorting to a pseudo transient approach. The performance of the resulting three- and the four-step steady algorithms are compared with the well-known SIMPLE method in solving the steady flow problems on unstructured grids. The performance of the general three- and the four-step projection methods are also compared in solving the unsteady flow problems.     

Electrochemically polymerized 2,2-dimethyl-3,4-propylenedioxythiophene on carbon fiber for microsupercapacitor

ProDOT(Me)₂ was electrochemically polymerized onto a carbon fiber microelectrode (CFME) by cyclovoltammetry under a wide potential range (0–1.6 V) with well-defined parameters. The nano to micron scale coatings on CFMEs were characterized by cyclovoltammetry, ex situ FTIR attenuated total reflectance spectroscopy (FTIR-ATR), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM and EDX). The existence of a capacitance behavior is shown by Nyquist, Bode phase relationship.     

Levitation Force Density on Different Thicknesses of?YBa2Cu3O7?x Bulk Superconductor Fabricated by?FQMG?Process

A precursor YBCO in the stoichiometric ratio of 1:2:3 was prepared by the flame-quench-melt-growth (FQMG) method. Both the superconducting and nonsuperconducting regions were decided by measuring the magnetic levitation force per unit volume as a function of thickness of the superconducting sample. It was determined that superconducting forming ratio depends on where it forms in the sample, and thus a region near the top surface of the sample contains more superconducting forming ratio than the other regions. The levitation force density measured at different thicknesses of the sample ranging from 6.54 to 1.58 mm firstly increased and then separately reached a saturation point (maximum value) for both repulsive and attractive levitation force density. It was found that the maximum values of the repulsive and attractive levitation forces were respectively 125 mN/cm³ and ?23 mN/cm³. The considerably improved F _L ?z performance in FQMG sample can be translated to large-scale Y123 blocks intended for real superconducting levitation applications.     

The electrical characteristics of Al/p-InP Schottky contacts

In this study, it has been investigated the electrical characteristics of identically prepared Al/p-InP Schottky diodes. The barrier heights (BHs) and ideality factors of all devices have been calculated from the electrical characteristics. Although the diodes were all identically prepared, there was a diode-to-diode variation: the effective barrier heights ranged from 0.83 ± 0.01 to 0.87 ± 0.01 eV, and the ideality factors ranged from 1.13 ± 0.02 to 1.21 ± 0.02. The barrier height vs. ideality factor plot has been plotted for the devices. Lateral homogeneous BH was calculated as a value of 0.86 eV from the observed linear correlation between BH and ideality factor, which can be explained by laterally inhomogeneities of BHs. The values of barrier height and free carrier concentration yielded from the reverse bias capacitance-voltage (C-V) measurements ranged from 0.86 ± 0.04 to 1.00 ± 0.04 eV and from (3.47 ± 0.39) × 10¹⁷ to (4.90 ± 0.39) × 10¹⁷ cm⁻³, respectively. The mean barrier height and mean acceptor doping concentration from C-V characteristics have been calculated as 0.91 eV and 3.99 × 10¹⁷ cm⁻³, respectively.     

Glucose signalling pathway controls the programmed ribosomal frameshift efficiency in retroviral-like element Ty3 in Saccharomyces cerevisiae

Ty3 elements of S. cerevisiae contain two overlapping coding regions, GAG3 and POL3, which are functional homologues of retroviral gag and pol genes, respectively. Pol3 is translated as a Gag3-Pol3 fusion protein dependent on a +1 programmed frameshift at a site with the overlap between the two genes. We show that the Ty3 frameshift frequency varies up to 10-fold in S. cerevisiae cells depending on carbon source. Frameshift efficiency is significantly lower in cells growing on glucose as carbon source than in cells growing on poor alternative carbon sources (glycerol/lactate or galactose). Our results indicate that Ty3 programmed ribosomal frameshift efficiency in response to glucose signalling requires two protein kinases: Snf1p and cAMP-dependent protein kinase A (PKA). Increased frameshifting on alternative carbon sources also appears to require cytoplasmic localization of Snf1p, mediated by the Sip2p protein. In addition to the two required protein kinases, our results implicate that Stm1p, a ribosome-associated protein involved in nutrient sensing, is essential for the carbon source-dependent regulation of Ty3 frameshifting. These data indicate that Ty3 programmed ribosomal frameshift is not a constitutive process but that it is regulated in response to the glucose-signalling pathway.