Significance of Dufour and Soret effects on the non-Darcy flow of Cross fluid by a tilted plate with radiation and chemical reaction: A Cattaneo–Christov heat flux model

The Darcy–Forchheimer flow model is substantial in the fields where a high flow rate effect is a common phenomenon, for instance, in petroleum engineering. In this paper, we aim to scrutinize the aspects of cross-diffusion effects on the non-Darcy flow of Cross fluid by a tilted plate with thermal radiation and chemical reaction. Metamorphosed equations are resolved with the combination of shooting and Runge–Kutta fourth-order procedures. The correlation coefficient is used to discuss the impact of pertinent parameters on friction factor and transfer rates (heat and mass). The main findings of this study are that the Dufour number escalates fluid temperature and the Soret number ameliorates the fluid concentration. It is observed that the fluid velocity minifies with the elevation in the Forchheimer number. And also, it is perceived that the heat transfer rate has a generous positive relationship with the thermal relaxation parameter. Furthermore, validation of current results with the earlier results under specified conditions is performed and an adequate concord is seen.     

Improvement of Lubrication Performance in External Gear Machines through Micro-surface Wedged Gears

This article demonstrates how a properly designed micro-surface linear wedge added to the lateral surfaces of the gear teeth can improve the lubricating ability of external gear machines (EGMs), resulting in lower power losses and chance of wear during their operation. The approach of study is based on the use of a fluid structure interaction (FSI) model for the analysis of the lateral lubricating gaps developed in the authors' research team. Such a model is used to determine the best design of the wedged gear by considering the overall axial balance problem of pressure compensated EGMs for high-pressure applications. The article shows the numerical predictions along with the experimental verifications of the advantages offered by the proposed solution in terms of torque loss reduction for a particular reference pump.     

Alternative adhesion sites in human fibrinogen for vascular endothelial cells

Fibrinogen mediates endothelial cell adhesion, spreading, and angiogenesis through integrin alphavbeta3. Previous studies by several investigators have suggested that the Arg-Gly-Asp (RGD) site at position 572-574 on the alpha chain of human fibrinogen can bind to alphavbeta3. However, this RGD sequence is absent in fibrinogen from most other species, including bovine, hamster, monkey, mouse, pig, and rat fibrinogen. In these species, an RGD site exists at the equivalent of position alpha252-254, which has the sequence RGG in humans. In addition, the role of an integrin binding site on the gamma chain at position 400-411 has been an issue of controversy. In the present studies, recombinant fibrinogen molecules with mutations in the potential endothelial cell binding sites have been used to test the role of these sites directly. The results show that the RGD at alpha572-574 is the primary adhesion site, and that the gamma chain site plays no significant role. Human and bovine plasma fibrinogens were also assayed for their ability to support adhesion of human and bovine vascular endothelial cells. The results show that although the two types of fibrinogen have RGD sequences at widely divergent sites, there is no significant difference in their ability to support endothelial cell adhesion. Furthermore, a chimeric human fibrinogen molecule with an RGD sequence at the bovine site, position alpha252-254, also supported adhesion. These results indicate that an RGD site in human fibrinogen at either position alpha252-254 or position alpha572-574 can mediate endothelial cell adhesion.     

Lupus anticoagulants and antiphospholipid antibodies

In recent years, clinical syndromes involving lupus anticoagulants and antiphospholipid antibodies have come into increasing clinical prominence. Since the discovery that most antiphospholipid antibodies require the presence of anionic phospholipid-binding proteins such as B2-glycoprotein I and prothrombin, a large number of studies have attempted to delineate the specificity of these antibodies. Several mechanisms have been proposed to explain the hypercoagulable state associated with these antibodies. This review attempts to summarize these data and the challenges that confront efforts to delineate the pathogenesis of the prothrombotic state associated with the presence of these antibodies.     

Dual layer matching (20 MHz) piezoelectric transducers with glassand parylene

This study describes a method of applying very thin broadband matching layers to 2 mm diameter 20 MHz transducers. Dual layer acoustic matching between the ceramic and the medium at the front face of the transducer was accomplished by selecting 1/4 wavelength glass layers from a commercial source, epoxying them to the ceramic, and vapor depositing parylene to 1/4 wavelength thickness on the glass. A 8 dB fractional bandwidth of 0.75 and insertion loss of -10 dB was found on the average for these transducers. This method allowed fabricating probes that performed well, were reproducible, provided both a matching and protection coating, and could be fabricated in a practical manner     

Strain-induced modifications of the band structure ofInxGa1-xP-In0.5Al0.5Pmultiple quantum wells

The effect of strain on the band structure of In_xGa_1-xP-In_0.5Al_0.5P multiple quantum wells (MQW's) has been investigated from high-pressure and low-temperature photoluminescence measurements. The biaxial strain in the wells was varied between +0.6% compressive to -0.85% tensile strain by changing the well composition x from 0.57 to 0.37. Strain increases the valence band offsets in either tensile or compressively strained structures. Whereas relatively insensitive to tensile strain, the valence band offsets showed a strong dependence on the magnitude of the compressive strain. Good agreement is found between the measured valence band offsets and those predicted by the model solid theory, except for the largest compressively strained MQW's, for which the model calculations underestimate the measured valence band offset. Strain and the associated variations in composition also modified the separation among the well states associated with Γ_1c, L_1c , and X_1c. From these results, the bandgaps of each conduction band extrema were calculated in In_xGa_1-xP for 0.37相似文献   

108-GHz GaInAs/InP p-i-n photodiodes with integrated bias tees andmatched resistors

Connections to bulk bias tees and various mismatched loads degrade the usable frequency response of high-speed photodetectors. Monolithic integration of passive components to enhance the realizable performance of high-bandwidth, long-wavelength photodiodes is demonstrated. Circuits having bias tees and matched resistors integrated with 7-μm×7-μm photodiodes show usable electrical bandwidths exceeding 100 GHz     

Assessment of expression of Leloir pathway genes in wild-type galactose-fermenting Streptococcus thermophilus by real-time PCR

In this study, four galactose-positive (Gal⁺) Streptococcus thermophilus strains viz. AJM, JM1, KM3 and AUKD8 and one galactose-negative (Gal^?) S. thermophilus NCDC 218 were used to characterize the organization of Leloir pathway genes using long-range PCR, and expression of these genes were studied using real-time PCR, in presence of different sugars. Long-range PCR results showed that both Gal⁺ and Gal^? isolates, the gal–lac gene order (galRKTEM–lacSZ), are conserved including the size of individual genes. The promoter sequence of the three Gal⁺ isolates (AJM, JM1 and KM3) possessed single base pair deletion at ?28 region of galR and C to T substitution at ?9 box galK region. In contrast, Gal⁺ AUKD8 had A to T substitution at preceding ?25 region of galR. The expression of galK and galM grown in the presence of galactose was significantly higher in case of AJM (30- and 7.6-fold, respectively), followed by KM3 and JM1. In addition, galR, galT and galE showed higher expression in galactose, than in lactose and glucose medium. This study gives a preliminary idea on Leloir pathway gene expression in wild Gal⁺ S. thermophilus, and further studies may throw more light on the role of gal–lac operon in galactose metabolism.     

Beyond exchange models: Understanding the structure of B2B information systems

This paper provides a framework to characterize the structure of information systems that enable transactions between businesses. We propose that the structure of various inter-organizational information systems, including traditional EDI systems and more recent web based exchanges, can be characterized in terms of four underlying dimensions: control, relational support, integration, and technology dimensions. In our paper we explain and operationalize these dimensions as constructs, and examine how each of them might be affected by inter-organizational relationship or product specific antecedents. We argue that these dimensions are fundamental to more realistically representing an organizations involvement with and use of inter-organizational information systems. Further, we argue that specific product types and preexisting relationships between organizations will be strongly associated with the variables representing the dimensions of Inter-organizational information systems.     

Large-scale preparation of perchlorates directly from sodium chloride

Based on the optimum conditions arrived at in the laboratory experiments, large-scale trials have been carried out for the preparation of sodium perchlorate by the direct oxidation of sodium chloride in a single step using a graphite substrate lead dioxide anode.Two cells of 75 A capacity and one 400 A cell were run continuously at an anode current density of 20 A/dm² and a temperature of 45°–50°C. The cell performance with these anodes is given.Potassium and ammonium perchlorates formed by double decomposing the sodium perchlorate obtained by this method with the respective chlorides are pure and conform to the stringent specifications.Presented at the Eleventh Seminar on Electrochemistry held at Central Electrochemical Research Institute, Karaikudi-3 in November 1970.