New Layered Space-Time Schemes Based on Group of Three Transmit Antenna

We present a new architecture of layered space-time codes as a combination of Bell Laboratory Layered Space-Time (BLAST) architecture and of special Space Time Trellis (STTC) Codes which are variations about the Super Orthogonal Space-Time Trellis Codes (SOSTTC) first introduced by Ionescu et al in [1] [2] and further improved by Jafarkhani et al. in [3]. The system we propose is named Super Quasi Orthogonal Horizontal Layered Space Time Trellis Code (SQOHLSTTC). It consists in a powerful Space-Time Block Code (STBC) based STTC originally derived for a three transmit antenna system, together with an original block based decoding algorithm. The decoding algorithm of SQOHLSTTC combines group interference suppression and group interference cancellation techniques. To implement the system, we propose a low complexity hard decision iterative decoding method. System performances confirm the great interest of the proposed transmission scheme.     

Very low surface recombination velocity of crystalline silicon passivated by phosphorus‐doped a‐SicxNy:H(n) alloys

Hydrogenated and phosphorus‐doped amorphous silicon carbonitride films (a‐SiC_xN_y:H(n)) were deposited by plasma‐enhanced chemical vapor deposition (PECVD) on crystalline silicon surface in order to explore surface passivation properties. Very silicon‐rich films yielded effective surface recombination velocities at 1 sun‐illumination as low as 3 cm s⁻¹ and 2 cm s⁻¹ on 1 Ω cm p‐ and n‐type crystalline silicon substrates, respectively. In order to use them as anti‐reflection coating, we increased alternatively either the carbon or nitrogen content of these films. Also, a combination of passivation and antireflective films was analyzed. Finally, we explored the passivation stability under high‐temperature steps. Copyright © 2007 John Wiley & Sons, Ltd.     

Granulocyte macrophage-colony-stimulating factor mouthwashes heal oral ulcers during head and neck radiotherapy

Methylglyoxal was demonstrated to be a substrate for the isozymes E1, E2 and E3 of human aldehyde dehydrogenase. Pyruvate was the product from the oxidation of methylglyoxal by the three isozymes. At pH 7.4 and 25 degrees C, the major and minor components of the E3 isozyme catalyzed the reaction with Vmax of 1.1 and 0.8 mumol NADH min-1 mg-1 protein, respectively, compared to 0.067 and 0.060 mumol NADH min-1 mg-1 protein for the E1 and E2 isozymes, respectively. The E2 isozyme had a K(m) for methylglyoxal of 8.6 microM, the lowest compared to 46 microM for E1 and 586 and 552 microM for the major and minor components of the E3 isozyme, respectively. Both components of the E3 isozyme showed substrate inhibition by methylglyoxal, with Ki values of 2.0 mM for the major component and 12 mM for the minor component at pH 9.0. Substrate inhibition by methylglyoxal was not observed with the E1 and E2 isozymes. Methylglyoxal strongly inhibited the glycolaldehyde activity of the E1 and E2 isozymes. Mixed-type models of inhibition were employed as an approach to calculate the inhibition constants, 44 and 10.6 microM for E1 and E2 isozymes, respectively.     

Etude du transfert DE Cd, Pb, Cu ET Zn dans les chaines trophiques neritiques et estuariennes—I. Etat dans l'estuaire interne de la loire (France) au cours de l'ete 1978

In order to determine the behaviour of some trace elements (Cd, Pb, Cu, Zn) in estuarine biota, different species of crustaceans and fishes were taken up from the Loire estuary. The concentrations of metals were determined by atomic absorption.Except for Zn, the accumulation of metals is higher in crustaceans than in fishes and the phenomenon is particularly important for copper, a constituent of crustaceans respiratory pigment. The concentrations of metals are no more important for bottom-feeders than for other fishes. The highest levels are encountered for Zn followed by Cu, Pb and Cd. The Loire organisms are not so contaminated than those of the same species taken up from heavily polluted estuaries (Severn and Medway, G.-B.).Transfers in food chains were quantified with the transfer factor: f.t. = Concentration in the consumer/Concentration in the prey.For Cd, Pb and Cu, the transfer factor is generally inferior to 1, attaining exceptionally 2.01. Except in one case, it is higher than 1 for Zn. The concentration of trace elements in intestine content is higher than in stomach content, probably as a consequence of faeces enrichment by unassimilated metals. So, there is probably no biomagnification in estuarine food chain for Cd, Pb and Cu, the case of Zn being more ambiguous.     

Production of reduced-fat whipped toppings by solid fat-based W/O/W double emulsions: proof of concept

Water-in-oil-in-water (W/O/W) double emulsions present a reduced-fat alternative to conventional O/W food emulsions, as part of the dispersed oil phase is replaced with water. In this study, the concept of a reduced-fat whipped topping produced by W/O/W technology was proven. Whipping of a W/O/W emulsion, containing only 20% oil phase and a solid fat content of 78%, produced a superior whipped topping, in terms of firmness and overrun, compared to its whipped O/W emulsion counterparts. The presence of PGPR in the oil phase increased structure formation during whipping, while the additional dispersed-phase volume resulted in a better air inclusion. Two commercial monoacylglycerols (saturated and unsaturated) were investigated to improve the whipping properties of the produced W/O/W double emulsion. Both increased the susceptibility towards partial coalescence, thereby reducing whipping time and overrun, while increasing firmness of the produced whipped topping. Furthermore, the effect was stronger for the unsaturated than for the saturated monoacylglycerol.     

Ge/SiGe superlattices for thermoelectric energy conversion devices

Ge-rich multiple quantum well heterostructures have been investigated as engineered material for efficient thermoelectric generators monolithically integrated on silicon substrates. Thick Ge/SiGe multilayers on Si substrates designed for lateral thermoelectric devices have been grown and characterized in which electrical and thermal conduction occur parallel to the heterostructure interfaces. In this study, an overview of the investigated structures is presented together with results from X-ray scattering and transmission electron microscopy experiments. These analyses confirm the high quality of the material and the uniformity of the structure over the whole deposited thickness. Important parameters in terms of the optimization of the material quality which could affect thermoelectric properties, such as the interfaces roughness and the threading dislocation density, have also been evaluated. Preliminary electrical and Seebeck coefficient measurements indicate the viability of this material for the realization of thermoelectric devices.     

A novel combination of methane fermentation and MBR — Kubota Submerged Anaerobic Membrane Bioreactor process

Methane fermentation is considered one of the best placed biological processes to reduce volume of organic waste while keeping small sludge production and recovering energy. One of the disadvantages of early anaerobic digestion technologies was the long hydraulic retention time thus large capacity tanks were required to hold slow growing methanogenic bacteria. New technological attempts such as upflow anaerobic sludge blanket (UASB), fixed or fluidised bed and membrane bioreactor (MBR) appeared as countermeasures.Kubota’s submerged anaerobic membrane biological reactor (KSAMBR) process has been developed in the last decade and successfully applied in a number of full-scale food and beverage industries. It consists of a solubilization tank and a thermophilic digestion tank, the latter incorporating submerged membranes. The biogas generated can be utilized for water heating via boilers. Both permeate and waste anaerobic sludge are further treated in wastewater treatment facilities.One of the main advantages of KSAMBR is that membranes retain the methanogenic bacteria while dissolved methane fermentation inhibitors such as ammonia are filtered out with the permeate. This makes the KSAMBR process very stable. Furthermore, the digester volumes can be scaled down to 1/3 to 1/5 of the conventional digesters provided that biomass is 3 to 5 times as concentrated.Applications include stillage treatment plants for Shouchu (Japanese spirits made from sweet potato, rice or other grains), potato processing sites, sludge liquor and food factory treatment plants.In summary, it is believed that KSAMBR offers the best possible solution combining the benefits of methane fermentation process with the performance of membrane technology. More details will be presented in the proceedings paper and in the presentation.     

COARSE PARTICLE WALL FRICTION IN VERTICAL SLURRY FLOWS

Experiments have been conducted using spherical glass particles transported in a recirculating flow loop with internal pipe diameter of 40.9 mm by water and by ethylene glycol solutions. Particle diameters were 1.8 and 4.6 mm and the solids concentrations ranged from 9% to 38% by volume.

Pressure gradients have been interpreted in terms of a particle friction factor which depends upon factors first identified by R.A. Bagnold in experiments conducted by shearing neutrally buoyant suspensions in a concentric cylinder viscometer.     

2.3 A crystal structure of the catalytic domain of DNA polymerase beta

The crystal structure of the catalytic domain of rat DNA polymerase beta (pol beta) has been determined at 2.3 A resolution and refined to an R factor of 0.22. The mixed alpha/beta protein has three subdomains arranged in an overall U shape reminiscent of other polymerase structures. The folding topology of pol beta, however, is unique. Two divalent metals bind near three aspartic acid residues implicated in the catalytic activity. In the presence of Mn2+ and dTTP, interpretable electron density is seen for two metals and the triphosphate, but not the deoxythymidine moiety. The principal interaction of the triphosphate moiety is with the bound divalent metals.     

Power Factor Characterization of Ge/SiGe Thermoelectric Superlattices at 300 K

To accurately characterize the efficiency of thermoelectric materials and characterize the maximum power that they can produce, a device using micro/nanofabrication techniques has been developed, enabling all three properties included in the figure of merit, ZT, of a thermoelectric material to be measured using a single device. The fabrication and testing of the device are presented. The electrical conductivity and Seebeck coefficient of Ge/SiGe heterostructures grown by low-energy plasma-enhanced chemical vapor deposition are used for demonstration. Experimental results as a function of quantum well width are presented, demonstrating power factors up to 6.02 ± 0.05 mW m^?1 K^?2 at 300 K. Modeling and physical characterization demonstrate that these results are presently limited by high threading dislocation density.