Sep: A Fixed Degree Regular Network for Massively Parallel Systems

We propose a family of regular Cayley network graphs of degree three based on permutation groups for design of massively parallel systems. These graphs are shown to be based on the shuffle exchange operations, to have logarithmic diameter in the number of vertices, and to be maximally fault tolerant. We investigate different algebraic properties of these networks (including fault tolerance) and propose a simple routing algorithm. These graphs are shown to be able to efficiently simulate or embed other permutation group based graphs; thus they seem to be very attractive for VLSI implementation and for applications requiring bounded number of I/O ports as well as to run existing applications for other permutation group based network architectures.     

Grain Floatation During Equiaxed Solidification of an Al-Cu Alloy in a Side-Cooled Cavity: Part I—Experimental Studies

Experimental studies were performed to investigate the role and influence of grain movement on macrosegregation and microstructure evolution during equiaxed solidification. Casting experiments were performed with a grain-refined Al-Cu alloy in a rectangular sand mold. For the aluminum alloy studied, the equiaxed grains are lighter than the bulk melt and thus float up. Experiments were designed to investigate floatation phenomena of equiaxed grains in the presence of thermosolutal convection. Cooling curves were recorded at key locations in both the casting and the chill. Quantitative image analysis and spatial chemical analysis were performed on the solidified casting to observe the chemical and microstructural inhomogeneity created by the melt convection and solid floatation. Several notable features that can be attributed to grain movement were observed in temperature histories, macrosegregation patterns, and microstructures. In our experiments, the floatation of grains influences the thermal conditions and the overall flow direction in the casting cavity. In some cases, the induced flow resulting from the grain movement caused a flow reversal. This in turn influences the solidification direction, microstructure evolution, and the overall macrosegregation behavior.     

Chimeric anti-TAG72 receptors with immunoglobulin constant Fc domains and gamma or zeta signalling chains

High serum levels of cholesterol and triglycerides are risk factors for coronary heart disease and are strongly related to several haemostatic parameters. Thyroid disorders are a frequent feature in hyperlipidemic patients and are also associated with a variety of haemostatic abnormalities. Therefore, we analysed the relationships between free T4 (fT4) levels and Factor VII and VIII activities (FVIIc and FVIIc), D-Dimers (DDI) and Plasminogen Activator Inhibitor type 1 (PAI-1), in a group of 472 healthy patients referred for hyperlipidemia. Fourty patients were found to have primary hypothyroidism. A negative correlation was found in the whole study population between fT4 and DDI (p = 0.0001, r = -0.21) and the same results were found after exclusion of the patients with fT4 below the normal range (p = 0.0007, r = -0.17). In a multivariate regression analysis, the relationship between DDI and fT4 was independent of age, Body Mass Index (BMI), gender and total cholesterol. Less impressive correlation coefficients were found with FVIIc (r = -0.10), FVIIIc (r = -0.09) and PAI-1 (r = -0.09). These results suggest that fT4 may play a physiological role in the regulation of the haemostatic equilibrium in hyperlipidemic patients and that low levels of fT4 are associated with a hypercoagulable state.     

Non-catalytic vanadium removal from vanadyl etioporphyrin (VO-EP) using a mixed solvent of supercritical water and toluene: A kinetic study

Reaction kinetics and mechanisms of the decomposition of vanadyl etioporphyrin (VO-EP), the most common metal compounds present in heavy crude, were studied in a mixed solvent of supercritical water (SCW) and toluene without the addition of any catalyst, H₂ or H₂S to remove vanadium. The aim of this study was to remove vanadium an environmentally benign way from VO-EP at a high extent and in a short reaction time. The experiments were conducted in an 8.8 mL batch reactor fabricated from Hastelloy C-276. The capability of SCW to remove vanadium from VO-EP was discovered at temperatures of 410–490 °C and a water partial pressure (WPP) of 25 MPa. Experimental results revealed that the overall VO-EP conversion was 90.51% at a temperature of 490 °C, WPP of 25 MPa and reaction time of 180 min. Under the same reaction conditions, approximately 80.26% vanadium was removed by reaction with SCW. The global reaction followed first order kinetics, with Arrhenius parameters of activation energy 8.93 kcal/mol and a pre-exponential factor 5.66 s^?1. A kinetic model of demetallation that well-fit the experimental results, was proposed. The reaction kinetics may be critically explained in terms of free radical mechanism. The obtained results suggest that SCW is capable of removing vanadium from VO-EP.     

Studies of extraction of methylene blue from synthetic waste water using liquid emulsion membrane technology

A comprehensive study pertaining to liquid emulsion membrane (LEM) extraction process of methylene blue from wastewater is presented. The liquid membrane is made of an emulsifying agent (Monumal 80) with various organic diluents. Surfactant (5 wt%) (Monumal 80) and kerosene gave good extraction. Important variables affecting LEM permeation process include stability of membrane, contact time of extraction, strip phase concentration, treat ratio (strip phase: organic phase), stirring speed, feed phase concentration were systematically studied for percentage of extraction by LEM. Kerosene as diluent gave 99.57% extraction with NaOH as strip phase. © 2012 Canadian Society for Chemical Engineering     

Role of heat transfer and thermal conductivity in the crystallization behavior of polypropylene‐containing additives: A phenomenological model

The thermal conductivity of a filler and the thermal conductivity of a composite made from that filler influence the heat‐transfer process during melt processing. The heat‐transfer process from the melt to the mold wall becomes an important factor in developing the skin–core morphology. These aspects were examined in this study. The thermal conductivity of polypropylene–filler composites was estimated with a standard model for various fillers such as calcium carbonate, talc, silica, wollastonite, mica, and carbon fibers. The rate of cooling under given conditions, including the melting temperature, mold wall temperature, mass of the composite, and filler content, was estimated with standard heat‐transfer equations. The time to attain the crystallization temperature for polypropylene was evaluated with a regression method with differential temperature steps. The crystallization curves were experimentally determined for the different fillers, and from them, the induction period for the onset of crystallization was estimated. These observations were correlated with the expected trends from the aforementioned formalism. The excellent fit of the curves showed that in all these cases, the thermal conductivity of the filler and composite played a dominant role in controlling the onset of the crystallization process. However, the nucleation effects became important in the later stages after the crystallization temperature was attained. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2994–2999, 2003     

Experimental study of paddy drying in a vortex chamber

The intensification of interfacial mass, heat, and momentum transfer makes vortex chambers potentially interesting for the efficient drying of paddy, allowing shorter drying times and/or more compact equipment. The presence of a shell introduces particular challenges. Intraparticle diffusion limitations are strong and may reduce the advantage from intensified interfacial mass and heat transfer and the efficiency of air usage. Furthermore, high shear and normal stresses in the fast rotating particle bed may cause damage to the paddy shell, posing problems for transport and storage. With these specific aspects in mind, the use of vortex chambers for paddy drying is experimentally evaluated.     

Synthesis and Characterization of Some Triphenyltin(IV) Complexes from Sterically Crowded [((E)-1-{2-Hydroxy-5-[(E)-2-(aryl)-1-diazenyl]phenyl}methylidene)amino]acetate Ligands and Crystal Structure Analysis of a Tetrameric Triphenyltin(IV) Compound

Four new triphenyltin(IV) complexes containing [((E)-1-{2-hydroxy-5-[(E)-2-(aryl)-1-diazenyl]phenyl}methylidene)amino]acetate ligands (L) have been synthesized with formulations of Ph₃SnLH. They have been studied by multinuclear (¹H, ¹³C, ¹¹⁹Sn) NMR, ¹¹⁹Sn M?ssbauer and IR spectroscopy. A full characterization of one complex, Ph₃SnL¹H (1), was accomplished by single crystal X-ray crystallography, which revealed the compound to be a macrocyclic tetramer. In the tetramer, the five coordinate tin atoms have distorted trigonal bipyramidal geometries with the three phenyl groups occupying equatorial positions, while an oxygen atom of the carboxylate group of one L ligand and the oxide O-atom (formerly the hydroxy group) of a second L ligand in an apical positions. The carboxylate ligands bridge adjacent tin atoms and coordinate in the zwitterionic form with the phenolic proton moved to the nearby nitrogen atom. ¹¹⁹Sn NMR results indicate that the tetrameric structures of the complexes in the solid state, in which the tin atoms are five-coordinated, dissociate in solution to yield four coordinate monomeric species.     

Characterization of pHEMA-based hydrogels that exhibit light-induced bactericidal effect via release of NO

A light-activated NO donor, [Mn(PaPy₃)(NO)]ClO₄ (1a), has been incorporated into HEMA-based polymer hydrogel and the nitrosyl-polymer conjugate materials 1a_x · HG and 1a_x · HG^MB have been characterized. The NO releasing properties and antibacterial capabilities of these materials in conjunction with growth attenuators such as hydrogen peroxide and methylene blue (MB) are reported. Since the nitrosyl releases NO only upon exposure to light, materials like 1a_x · HG^MB could be used as wound dressings that deliver NO under controlled conditions.