Optimized and load balanced clustering for wireless sensor networks to increase the lifetime of WSN using MADM approaches

Wireless Networks - The power utilization has verified as a major problem in wireless sensor networks (WSNs). Many researchers have provided efficient solutions for power utilization. Clustering is...     

Novel framework for secured bulk creation of virtual machine in IaaS platform

Software Quality Journal - Cloud service providers (CSPs) like Amazon Web Services, Google Engine, and Microsoft Azure have the major share in providing cloud-related services globally. Their...     

Control of time-dependent effects in steel-concrete composite frames

Studies are presented for the control of time-dependent effects of creep and shrinkage in steel-concrete composite frames with pre-cast concrete slab for both shored and un-shored constructions. A developed hybrid procedure has been used for carrying out the studies. The procedure accounts for creep, shrinkage and progressive cracking in concrete slab panels. Two frames, a single storey and a five storey frame are considered. It is shown that, for both the types of constructions, shored and un-shored, the increase in bending moments and mid-span deflections can be controlled to a significant degree, without putting constraints on design parameters, by simply delaying the time of mobilization of composite action between the pre-cast concrete slab panels and the steel section. It is also found that though there is insignificant effect of type of construction on bending moments, the percentage change in mid-span deflection due to creep and shrinkage is significantly higher for shored construction.     

Uricase-immobilization on radiation grafted polymer support for detection of uric acid using Ag-nanoparticle based optical biosensor

A functional polymer support was designed for covalent immobilization of enzyme uricase, which was further utilized in a single enzyme based silver nanoparticles (Ag-NPs)-optical biosensor system for estimation of uric acid. A carboxylic acid functionalized polymer support was fabricated via gamma radiation induced mutual-irradiation grafting of polyacrylic acid (PAA) on to non-woven polypropylene (PP) matrix. Grafting parameters, such as dose, monomer concentration, homopolymer inhibitor and inorganic acid concentration were studied to optimize the grafting process. PAA-g-PP samples were characterized by grafting yield measurement, water uptake, FTIR, TGA and SEM techniques. Uricase enzyme was immobilized on to the PAA-g-PP support via covalent amide linkage using coupling agents, namely N-hydroxysuccinimide (NHS) and N-ethyl-N′-(3-(dimethylamino)propyl)carbodiimide (EDC). The catalytic activity of uricase was investigated spectrophotometrically using uric acid as a substrate. Study of kinetic parameters (K_m, V_max) revealed the value of K_m for covalently immobilized uricase to be ∼1.2-fold higher than that of free enzyme. The uricase-immobilized-PAA-g-PP samples could be repeatedly used for ∼20 cycles over a period of 30 days when stored in phosphate buffer (pH∼7.4) at 4°C without significant decrease in the enzyme activity. The uricase immobilized samples were successfully used in conjunction with the radiolytically synthesized Ag-NPs as a LSPR-optical biosensor for estimation of uric acid.     

Effect of hydrophilic and hydrophobic polymers on permeation of S-amlodipine besylate through intercalated polymeric transdermal matrix: 3(2) designing,optimization and characterization

Objective: Innovation in material science has made it possible to fabricate a pharmaceutical material of modifiable characteristics and utility, in delivering therapeutics at a sustained/controlled rate. The objective of this study is to design and optimize the controlled release transdermal films of S-Amlodipine besylate by intercalating hydrophilic and hydrophobic polymers.

Methods: 3(2) factorial design and response surface methodology was utilized to prepare formulations by intercalating the varied concentration of polymers(A) and penetration enhancer(B) in solvent. The effect of these independent factors on drug release and flux was investigated to substantiate the ex-vivo, stability and histological findings of the study.

Results: FTIR, DSC revealed the compatibility of drug with polymers; however, the semicrystallinity in drug was observed under PXRD. SEM micrographs showed homogeneous dispersion and entanglement of drug throughout the matrix. Results from the permeation study suggested the significant effect of factors on the ex vivo permeation of drug. It was observed that drug release was found to be increased with an increase in hydrophilic polymer concentration and PE. The formulations having polymers (EC:PVPK-30) at 7:3 showed maximum drug release with highest flux (102.60?±?1.12?µg/cm²/h) and permeability coefficient (32.78?±?1.38?cm/h). Significant effect of PE on lipid and protein framework of the skin was also observed which is responsible for increased permeation. The optimized formulation was found to be stable and showed no-sign of localized reactions, indicating safety and compatibility with the skin.

Conclusion: Thus, results indicated that the prepared intercalated transdermal matrix can be a promising nonoral carrier to deliver effective amounts of drug.     

Effect of Dynamic Change in Strain Rate on Mechanical and Stress Corrosion Cracking Behavior of a Mild Steel

The current work analyzes the effect of the dynamic change in strain rate during tensile loading of a mild steel on its mechanical and stress corrosion behavior in 3.5 wt.% NaCl solution. The sample experiences high strain rate (10^?2 s^?1) up to 10, 15 and 20% of total deformation and then very low strain rate of 10^?6 s^?1 till fracture without any unloading in between. The behavioral characteristics of the steel under these circumstances are found to be different from that exhibited during complete loading till fracture both at high and slow strain rates separately. Total strain increases with the increase in the strain at which change in strain rate happens, and this is attributed to the generation of large number of dislocations at higher strain rate and subsequently release of dislocation at low strain rate during change over due to more time available for dynamic recovery. This observation is common for both in air and corrosive environment. One unique observation in this study is the higher total strain and lower strength observed during dynamic change in strain rate in the corrosive environment compared to that in air, which is attributed to the hydrogen-induced plasticity mechanism.     

The tale of proteolysis targeting chimeras (PROTACs) for Leucine-Rich Repeat Kinase 2 (LRRK2)

Here we present the rational design and synthetic methodologies towards proteolysis-targeting chimeras (PROTACs) for the recently-emerged target leucine-rich repeat kinase 2 (LRRK2). Two highly potent, selective, brain-penetrating kinase inhibitors were selected, and their structure was appropriately modified to assemble a cereblon-targeting PROTAC. Biological data show strong kinase inhibition and the ability of the synthesized compounds to enter the cells. However, data regarding the degradation of the target protein are inconclusive. The reasons for the inefficient degradation of the target are further discussed.     

Fabrication of zinc‐loaded hollow glass microspheres (HGMs) for hydrogen storage

The greatest challenge for a feasible hydrogen economy lies on the production of pure hydrogen and the materials for its storage with controlled release at ambient conditions. Hydrogen with its great abundance, high energy density and clean exhaust is a promising candidate to meet the current global challenges of fossil fuel depletion and green house gases emissions. Extensive research on hollow glass microspheres (HGMs) for hydrogen storage is being carried out world‐wide, but the right material for hydrogen storage is yet underway. But many other characteristics, such as the poor thermal conductivity etc. of the HGMs, restrict the hydrogen storage capacity. In this work, we have attempted to increase the thermal conductivity of HGMs by ZnO doping. The HGMs with Zn weight percentage from 0 to 10 were prepared by flame spheroidization of amber‐colored glass powder impregnated with the required amount of zinc acetate. The prepared HGMs samples were characterized using field emission‐scanning electron microscope (FE‐SEM), environmental SEM (ESEM), high‐resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy and X‐ray diffraction (XRD) techniques. The deposition of ZnO on the microsphere walls was observed using FE‐SEM, ESEM and HRTEM which was further confirmed using the XRD and ultraviolet–visible absorption data. The hydrogen storage studies done on these samples at 200 °C and 10‐bar pressure for 5 h showed that the hydrogen storage increased when the Zn percentage in the sample increased from 0 to 2%. The percentage of zinc beyond 2, in the microspheres, showed a decline in the hydrogen storage capacity. The closure of the nanopores due to the ZnO nanocrystal deposition on the microsphere surface reduced the hydrogen storage capacity. The hydrogen storage capacity of HAZn2 was found 3.26 wt% for 10‐bar pressure at 200 °C. Copyright © 2015 John Wiley & Sons, Ltd.