Experiments were performed to investigate the diffusion ignition process that occurs when hot inert gas (argon or nitrogen) is injected into the stoichiometric hydrogen-oxygen mixture at the test section. Detonation wave initiated by spark plug in the driver section in stoichiometric acetylene-oxygen mixture at P = 0.5 MPa and room temperature, propagates as incident shock wave in the driven section through inert gas after bursting the diaphragm separating the sections. At the end wall of driver section the inert gas is heated behind the reflected shock wave and then injected into the test section with the stoichiometric hydrogen-oxygen mixture through the hole 8 mm in diameter. An increase of the initial pressure of the combustible mixture in the test section from 0.2 to 0.6 MPa resulted in decrease of the minimum temperature of injected gas causing ignition from 1650 K to 850 K. At the same time the induction time for ignition process has increased from 190 to 320 s when hot argon was injected. For the injection of hot nitrogen an increase of the initial pressure of the combustible mixture from 0.2 to 0.4 MPa resulted in decrease of the minimum temperature of injected inert gas giving ignition from 1150 K to 850 K, and in increase of the induction time from 170 to 240 s. The results of experiments indicate that ignition occurs when the static enthalpy of injected mass of inert gas exceeds some critical value. The mechanism of ignition process was also studied by schlieren photography.

Abstract

           This paper presents the effect of corrugation geometry on the crushing behavior, energy absorption, failure mechanism, and failure mode of woven roving glass fibre/ epoxy laminated composite tube. Experimental investigations were carried out on three geometrical different types of composite tubes subjected to compressive loading. On the addition to a radial corrugated composite tube, cylindrical composite tube, and corrugated surrounded by cylindrical tube were fabricated and tested under the same condition in order to know the effect of corrugation geometry. 

This research presents the effect of radial corrugation geometry on the crushing behavior, energy absorption, failure mechanism, and failure mode of woven roving glass fibre/ epoxy laminated composite tube. Experimental investigations were carried out on three geometrical different types of composite tubes subjected to compressive loading. On the addition to a radial corrugated composite tube, cylindrical composite tube, and corrugated surrounded by cylindrical tube were fabricated and tested under the same condition in order to know the effect of corrugation geometry. 

Abstract: This paper is devoted to study the effect of corrugation geometry on the crushing behavior, energy absorption, failure mechanism, and failure mode of woven roving glass fibre/epoxy laminated composite tubes. A comprehensive experimental program has been carried out on three geometrically different types of composite tubes subjected to axial compressive loading conditions. A novel method has been developed to fabricate the radial laminated corrugated composite tubes, cylindrical composite tubes, and corrugated surrounded by cylindrical tubes. All are tested under the same condition to establish the effect of corrugation geometry.

This paper investigates the impact of the hand-hold positions on both antenna performance and the specific absorption rate (SAR) induced in the user’s head. A cellular handset with external antenna operating at GSM-900 frequency is modeled and simulated using a finite difference time-domain (FDTD)-based platform SEMCAD-X. A specific anthropomorphic mannequin (SAM) is adopted to simulate the user’s head, whereas a semirealistic CAD-model of three-tissues is designed to simulate the user’s hand. The results show that in case of the handset in hand close to head at different positions; the antenna total efficiency gets reduced to (14.5% - 5.9%) at cheek-position and to (27.5% to 11.8%) at tilt-position. The peak averaged SAR1g values in head close to handset without hand, are 4.67 W/Kg and 2.66 W/Kg at cheek and tilt-position, respectively. Due to the presence of hand, the SAR1g in head gets reduced to (3.67-3.31 W/Kg) at cheek-position and to (1.84-1.64 W/Kg) at tilt-position, depending on the hand-hold position.

A large body of evidence now implicates increased leukocyte-endothelial cell adhesion as a key early event in the development of diabetic retinopathy. We recently reported that raised activity of the glycosylating enzyme core 2 beta 1,6-N-acetylglucosaminyltransferase (GlcNAc-T) through protein kinase C (PKC)beta2-dependent phosphorylation plays a fundamental role in increased leukocyte-endothelial cell adhesion and capillary occlusion in retinopathy. In the present study, we demonstrate that following exposure to plasma from diabetic patients, the human promonocytic cell line U937 exhibits a significant elevation in core 2 GlcNAc-T activity and increased adherence to cultured retinal capillary endothelial cells. These effects of diabetic plasma on enzyme activity and cell adhesion, mediated by PKCbeta2-dependent phosphorylation of the core 2 GlcNAc-T protein, were found to be triggered by increased plasma levels of tumor necrosis factor (TNF)-alpha. Levels of enzyme activity in plasma-treated U937 cells were closely dependent on the severity of diabetic retinopathy, with the highest values observed upon treatment with plasma of patients affected by proliferative retinopathy. Furthermore, we noted much higher correlation, as compared with control subjects, between increased values of core 2 GlcNAc-T activity and cell adhesion properties. Based on the prominent role of TNF-alpha in the development of diabetic retinopathy, these observations further validate the significance of core 2 GlcNAc-T in the pathogenesis of capillary occlusion, thereby enhancing the therapeutic potential of specific enzyme inhibitors.

urpose This study sets out to explore the impact of organisational culture innovation on the adoption of information systems (IS) in Libya's oil and banking sectors. Design/methodology/approach Using a structured survey questionnaire based on Cameron and Quinn's Organisational Culture Assessments Instrument (OCAI), 400 questionnaires were administered to middle and top management employees in more than 15 government and public organisations in Libya's oil and banking sectors. Findings The findings showed that there is a relationship between organisational culture innovations and the adoption of IS. The findings also showed that there are no differences in the organisational culture type between the two sectors covered in this study. Originality/value The findings imply that organisational culture innovations are influenced by other factors, which are worthy of investigation. The future implications of this research are also discussed.

 carbon materials2 through their unique combination of excellent processability and high carbon yield. The enediyne functionality of the monomers undergo a thermal Bergman cycloaromatization reaction that yields reactive naphthalene diradicals which polymerize to form polynapthalene.(Figure 1) The tetrafunctionality of the monomers allows for both a higher processing window due to extensive branching and ultimately the formation of network polymers. The high carbon yield results in less shrinkage of the polymer upon pyrolysis to the glassy carbon state. This allows for the faithful templating of carbon structures from a polymeric precursor.

Hydrogen fuel cell electrodes require several properties for optimum performance. An ideal electrode would have as high a surface area as possible with an uniform dispersion of nano-scale catalyst particles attached to the surface. The electrode must be electrically conductive and have good mass transport for products and reactants. Carbon supported platinum is the best known catalyst for the oxidation of hydrogen at the anode and the reduction of oxygen at the cathode of a proton exchange membrane fuel cell (PEMFC) 3. The material also must have good compatibility with the material used for the proton exchange membrane in the membrane electrode assembly (MEA), usually a sulfonated fluoropolymer such as Nafion. We have undertaken a study to prepare a high surface area carbon material through a BODA templating method which can then be functionalized with both well dispersed platinum nanoparticles …