Laminar compressible flow between close rotating disks: An asymptotic and numerical study

Laminar steady compressible flow between close rotating thermally conducting axisymmetric disks with inflow was investigated by means of a numerical solution of the Navier-Stokes equation and an asymptotic analysis. The approximate solution, obtained for small ?, E and H (Rossby and Ekman numbers, and height/radius, respectively) is valid for “merged”, “close” and “separate” boundary layers on the disks, corresponding to β? 1, $\text{β ? 1}$ and β? 1, respectively (where $\text{β =}\text{H}\text{2}\text{√}\text{E}\text{ρ}$, and ρ is the non-dimensional density). These three cases may appear simultaneously in different regions of the same system due to the large variation of ρ in the radial direction. The small ? (i.e. negligible convection terms) does not necessarily imply small perturbations of the pressure, and a special treatment of the pressure term was used in order to account for this feature, which sometimes culminates in inversion of the radial pressure gradient. Thenumerical solution was obtained by a finite-difference, modified Cheng-Allen method, using a non-uniform mesh. The numerical and the approximate solution are in good agreement.     

Influence of reference domain unstability upon the precision of random reference quantizer with uniformly distributed auxiliary source

The paper approaches the effect of domain unstability in random reference in the case of Random Reference Quantizer (RRQ) with uniformly distributed reference and a constant input signal. It is mainly concerned with emphasizing the influence of the finite sample number upon the final error of the mean value of the RRQ output.     

Determination of three-dimensional structures of proteins by simulated annealing with interproton distance restraints. Application to crambin, potato carboxypeptidase inhibitor and barley serine proteinase inhibitor 2

An automated method, based on the principle of simulated annealing,is presented for determining the three-dimensional structuresof proteins on the basis of short (<5 Å) interprotondistance data derived from nuclear Overhauser enhancement (NOE)measurements. The method makes use of Newton's equations ofmotion to increase temporarily the temperature of the systemin order to search for the global minimum region of a targetfunction comprising purely geometric restraints. These consistof interproton distances supplemented by bond lengths, bondangles, planes and soft van der Waals repulsion terms. The latterreplace the dihedral, van der Waals, electrostatic and hydrogen-bondingpotentials of the empirical energy function used in moleculardynamics simulations. The method presented involves the implementationof a number of innovations over our previous restrained moleculardynamics approach [Clore,G.M., Brünger,A.T., Karplus,M.and Gronenborn,A.M. (1986) J. Mol. Biol., 191, 523–551].These include the development of a new effective potential forthe interproton distance restraints whose functional form isdependent on the magnitude of the difference between calculatedand target values, and the design and implementation of robustand fully automatic protocol. The method is tested on threesystems: the model system crambin (46 residues) using X-raystructure derived interproton distance restraints, and potatocarboxypeptidase inhibitor (CPI; 39 residues) and barley serineproteinase inhibitor 2 (BSPI-2; 64 residues) using experimentallyderived interproton distance restraints. Calculations were carriedout starting from the extended strands which had atomic r.m.s.differences of 57, 38 and 33 Å with respect to the crystalstructures of BSPI-2, crambin and CPI respectively. Unbiasedsampling of the conformational space consistent with the restraintswas achieved by varying the random number seed used to assignthe initial velocities. This ensures that the different trajectoriesdiverge during the early stages of the simulations and onlyconverge later as more and more interproton distance restraintsare satisfied. The average backbone atomic r.m.s. differencebetween the converged structures is 2.2 ± 0.3 Åfor crambin (nine structures), 2.4 ± 0.3 Å forCPI (eight structures) and 2.5 ± 0.2 Å for BSPI-2(five structures). The backbone atomic r.m.s. difference betweenthe mean structures derived by averaging the coordinates ofthe converged structures and the corresponding X-ray structuresis 1.2 Å for crambin, 1.6 Å for CPI and 1.7 Åfor BSPI-2.     

Identification and composition of turnip root lipids

Two varieties of turnip, Laurentian and Wye, were examined for their lipid and fatty acid composition. Lipids extracted with 80% ethanol contained variable quantities of phosphatidic acid, which was considered to be an artifact. Crude lipids were fractionated by TLC, and fatty acids and sterols were analyzed by GLC. Among the common phospholipids, cardiolipid and phosphatidyl glycerol were abundant components. Linolenic acid comprised 60% of the total fatty acids. β-Sitosterol was the principal sterol, and about half of the carotenoids was lycopene. No great differences between the two varieties studied were observed however. Contribution No. 53 of the Food Research Institute, Canada Department of Agriculture, Ottawa.     

Membrane microviscosity in cell/virus systems

The use of fluorescent probes for the appraisal of microviscosity properties of cell membranes, both inside the lipid double layer and/or near the double layer surface, are today an usual tool in cell biology. In the present paper an attempt was made to establish if there are significant changes in the mechanical properties of the host cell membranes.     

The S1, S2 and SGA1 ancestral genes for the STA glucoamylase genes all map to chromosome IX in Saccharomyces cerevisiae

The polymorphic extracellular glucoamylase-encoding genes STA1 (chr. IV), STA2 (chr. II) and STA3 (chr. XIV), from Saccharomyces cerevisiae var. diastaticus probably evolved by genomic rearrangement of DNA regions (S1, S2 and SGA1) present in S. cerevisiae, and subsequent translocation to unlinked regions of chromosomal regions. S1, encoding a homologue to the threonine/serine-rich domain of STA glucoamylases (GAI-III), mapped to the right arm of chromosome IX. S2, encoding the hydrophobic leader peptide of GAI-III, was also mapped on the right arm of chromosome IX, next to S1, close to DAL81. The SGA1 sporulation-specific, intracellular glucoamylase-encoding gene is located on the left arm of chromosome IX, 32 kb proximal of HIS5.     

Four‐junction spectral beam‐splitting photovoltaic receiver with high optical efficiency

A spectral beam‐splitting architecture is shown to provide an excellent basis for a four junction photovoltaic receiver with a virtually ideal band gap combination. Spectrally selective beam‐splitters are used to create a very efficient light trap in form of a 45° parallelepiped. The light trap distributes incident radiation onto the different solar cells with an optical efficiency of more then 90%. Highly efficient solar cells including III–V semiconductors and silicon were fabricated and mounted into the light trapping assembly. An integrated characterization of such a receiver including the measurement of quantum efficiency as well as indoor and outdoor I–V measurements is shown. Moreover, the optical loss mechanisms and the optical efficiency of the spectral beam‐splitting approach are discussed. The first experimental setup of the receiver demonstrated an outdoor efficiency of more than 34% under unconcentrated sunlight. Copyright © 2010 John Wiley & Sons, Ltd.