Behaviour of Al-Mg alloys at high temperature

The behaviour of a few Al-Mg alloys (up to 7.1 wt% Mg) has been studied on heating in air at 500°C for 8 h or more. The precipitation of a spinel phase, MgAl₂O₄, is found to take place on the surface and along the transverse section (depth) of the specimen. The alloys seem to be resistant to internal oxidation below 4.5% Mg and thereafter prone to it. Beryllium modification does not suppress the progress of internal oxidation taking place in the Al-Mg alloys. The results have been interpreted on the basis of anodized photomicrographs and X-ray diffraction data.     

Load Balanced Congestion Adaptive Routing for Randomly Distributed Mobile Adhoc Networks

In mobile ad hoc networks, congestion occurs due to limited sources of the network, which leads to packet losses, bandwidth degradation and wastes time and energy on congestion recovery. Various techniques have been developed in attempt to minimize congestion in uniformly distributed networks. In this paper, a load balanced congestion adaptive routing algorithm has been proposed for randomly distributed networks. In the proposed algorithm two metrics: traffic load density and life time associated with a routing path, have been used to determine the congestion status and weakest node of the route. The route with low traffic load density and maximum life time is selected for packet transmission.     

Hybrid composite friction materials reinforced with combination of potassium titanate whiskers and aramid fibre: Assessment of fade and recovery performance

Composite friction materials based on synergistic ternary combination of potassium titanate whiskers, aramid fibre and graphite have been characterized for friction braking performance on Krauss friction tester. The dynamics of friction build-up and friction-decay as a function of number of braking instances and modes of braking cycles have been found to be more consistent in the composites with ≥7.5 wt% of aramid fibres whereas the absolute friction effectiveness remained higher in the composites with ≥25 wt% of potassium titanate whiskers. Wear surface morphology has revealed topographical variations and their underlying role in controlling the friction and wear performance.     

Macro-to-micro porous special bioactive glass and ceftriaxone-sulbactam composite drug delivery system for treatment of chronic osteomyelitis: an investigation through in vitro and in vivo animal trial

A systematic and extensive approach incorporating in vitro and in vivo experimentation to treat chronic osteomyelitis in animal model were made using antibiotic loaded special bioactive glass porous scaffolds. After thorough characterization for porosity, distribution, surface charge, a novel drug composite were infiltrated by using vacuum infiltration and freeze-drying method which was subsequently analyzed by SEM-EDAX and studied for in vitro drug elution in PBS and SBF. Osteomyelitis in rabbit was induced by inoculation of Staphylococcus aureus and optimum drug-scaffold were checked for its efficacy over control and parenteral treated animals in terms of histopathology, radiology, in vivo drug concentration in bone and serum and implant-bone interface by SEM. It was optimized that 60P samples with 60-65% porosity (bimodal distribution of macro- to micropore) with average pore size ~60 μm and higher interconnectivity, moderately high antibiotic adsorption efficiency (~49%) was ideal. Results after 42 days showed antibiotic released higher than MIC against S. aureus compared to parenteral treatment (2 injections a day for 6 weeks). In vivo drug pharmacokinetics and SEM on bone-defect interface proved superiority of CFS loaded porous bioactive glass implants over parenteral group based on infection eradication and new bone formation.     

Electronic absorption spectrum of Cu2 ions doped in lithium ammonium sulphate crystal

Single crystals of Lithium Ammonium Sulphate doped with Cu²⁺ ions were grown by slow evaporation technique. Electronic absorption spectra have been recorded at room and liquid nitrogen temperatures on Cary-2390 spectrophotometer. The spectrum is characteristic of a Cu²⁺ ion in octahedral symmetry. From the magnitude and and relative position of the bands a successful interpretation of all the observed bands has been made. The crystal field and tetragonal field parameters are derived. The observed and calculated energies are in good agreement.     

Dispersion data for open suspended microstrip on Alumina and Gallium Arsenide substrates

Accurate dispersion data for open suspended microstrop on RT-duroid and fused quartz substrates was presented in an earlier paper by the authors. The present work repeats the same exercise for two more commonly used substrate materials, namely, Alumina and Gallium Arsenide. The results are new and will be a very useful addition to the millimeter-wave circuit designer's library.     

n-CdS/p-ZnIn2Se4 thin film solar cell

The photovoltaic behaviour of a CdS/ZnIn₂Se₄ vacuum-evaporated thin film solar cell is reported for the first time. Because of the band gap of ZnIn₂Se₄ (1.93 eV) this combination of semiconductor materials seems to be suitable for use as one of the junctions in tandem solar cell configurations. Uncoated cells exhibited efficiencies of the order of 1.5% under an illumination of 100 mW cm^-2.     

A Reversible Data Hiding Scheme for Interpolated Images Based on Pixel Intensity Range

Multimedia Tools and Applications - In this paper, we propose a novel interpolation and a new reversible data hiding scheme for upscaling the original image and hiding secret data into the...     

Energy Efficient Multitier Random DEC Routing Protocols for WSN: In Agricultural

Wireless Personal Communications - Fog computing is an emerging paradigm that provides confluence facilities between Internet of Things (IoT) devices and cloud. The fog nodes process the...