Cluster‐based mobility management algorithms for wireless mesh networks

Wireless mesh networks (WMNs) have been the recent advancements and attracting more academicians and industrialists for their seamless connectivity to the internet. Radio resource is one among the prime resources in wireless networks, which is expected to use in an efficient way especially when the mobile nodes are on move. However, providing guaranteed quality of service to the mobile nodes in the network is a challenging issue. To accomplish this, we propose 2 clustering algorithms, namely, static clustering algorithm for WMNs and dynamic clustering algorithm for WMNs. In these algorithms, we propose a new weight‐based cluster head and cluster member selection process for the formation of clusters. The weight of the nodes in WMN is computed considering the parameters include the bandwidth of the node, the degree of node connectivity, and node cooperation factor. Further, we also propose enhanced quality of service enabled routing protocol for WMNs considering the delay, bandwidth, hopcount, and expected transmission count are the routing metrics. The performance of the proposed clustering algorithms and routing protocol are analyzed, and results show high throughput, high packet delivery ratio, and low communication cost compared with the existing baseline mobility management algorithms and routing protocols.     

An Optimized and Hybrid Energy Aware Routing Model for Effective Detection of Flooding Attacks in a Manet Environment

In this work, the design of continuous time Fractional Order All-Pass Filter (FOAPF) is proposed. Two different design methods to realize the All-Pass Filter in the fractional domain with mathematical formulations and circuit results are investigated. The first design method is based on Fractional Order Elements (FOEs) where, FOEs of order α and β are utilized to develop a second order All-Pass Filter to the fractional domain. Whereas, in second design method, the fractional filter is approximated into higher order integer filters. The frequency response of the proposed design are validated using MATLAB (2018a) and conjointly with PSPICE (OrCAD 17.2). For first circuit design, FOEs are obtained using a single R–C parallel network. However, for the second circuit design Signal Flow Graph (SFG) approach is utilized. The evaluation of the realized FOAPF is also performed through the Lissajous pattern, AC analysis and Transient Analysis. After the simulations, the achieved results show that the second order FOAPF provides almost 180° phase shift for different values of α, β.

     

Effect of coexcipients on drug release and floating property of nifedipine hollow microspheres: A novel gastro retentive drug delivery system

A gastro retentive drug‐delivery system for nifedipine was developed by incorporating the drug in cellulose acetate hollow microspheres capable of floating on the gastric and intestinal fluid. The microspheres were prepared by solvent diffusion–evaporation technique in the presence of coexcipients like polyethylene glycol, dibutyl phthalate, and poly(ε‐caprolactone) using ethyl acetate as a dispersing solvent. Size of the microparticles depends upon the type and concentration of the excipient used. Microparticles exhibited floating properties on the simulated‐gastric fluid for >12 h. Their percentage buoyancy followed the rank order of: blank (no coexcipients) > dibutyl phthalate > polyethylene glycol > poly(ε‐caprolactone) after 15 h of floating. Release of nifedepine was enhanced by the addition of coexcipients. The drug release followed non‐Fickian transport in almost all formulations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 486–494, 2006     

Viscosity behavior of hydroxylated and acetoacetylated polyesters

Viscosity studies on polyester polymers are important for governing their processing characteristics before their industrial application. In this study, the viscosity properties of hydroxylated polyesters with different diols and partially acetoacetylated polyesters with different amounts of ethyl acetoacetate were examined. The melt viscosities of these polymers were measured with different shear rates and at varying temperatures. The results were analyzed with the Williams–Landel–Ferry equation. In high‐solid‐coatings applications, an understanding about the surface properties and thermodynamic quantities, such as cohesive energy density, the solubility parameter, and the Flory–Huggins interaction parameter, are important. To evaluate these quantities, an atomistic simulation methodology based on Accelrys software was used, which provided insights into the structures of these compounds for further applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2422–2435, 2006     

Laser dye diffusion in polymer solutions studied by spectrophotometry

A mathematical approach based on the combined application of Fick's law of diffusion and the Beer–Lambert law was used to measure the diffusion coefficient of dyes viz., coumarin 515 [3‐(1‐methylbenzimidazol‐2‐yl)‐7‐diethylaminocoumarin], POPOP [1,4‐bis (5‐phenyloxazolyl‐2‐yl) benzene], and exalite 416 {1,1,1′,1′‐tetraethyl‐5,5′‐diparaanisyl‐[2,3:5,6] diindanobenzene} in solutions of polystyrene and poly(methyl methacrylate) in 1,4‐dioxane. Diffusion data agreed well with the published results obtained using other techniques. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1157–1165, 2004     

Finite element transient dynamic analysis of isotropic and fibre reinforced composite plates using a higher-order theory

A higher-order shear deformable C° continuous finite element is developed and employed to investigate the transient response of isotropic, orthotropic and layered anisotropic composite plates. The governing ordinary linear differential equations are integrated using the central difference explicit time integration scheme. A special mass matrix diagonalization scheme is adopted which conserves the total mass of the element and includes the effects due to rotary inertia terms. Numerical results for deflections and stresses are presented for rectangular plates under various boundary conditions and loadings. The parametric effects of the time step, finite element mesh, lamination scheme and orthotropy on the transient response are investigated. The numerical results are compared with those available in the literature, and with the results obtained by solving the same problems using the Mindlin plate element.     

Protective effect of dietary ginger on antioxidant enzymes and oxidative damage in experimental diabetic rat tissues

The role of oxidative stress has been reported in various diabetic complications. This study was undertaken to evaluate the protective effect of ginger, a medicinal plant, on the tissue antioxidant defence system and lipid peroxidative status in streptozotocin-induced diabetic rats. An increased reactive oxygen species and insufficient antioxidant activity are associated with diabetes mellitus, which is mainly responsible for diabetic pathogenesis. The role of ginger as antioxidant markers of liver and kidney were investigated. The antioxidant effect of the ginger was compared with glibenclamide, a well-known hypoglycaemic drug. The diabetic rats exhibited lower activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) and reduced glutathione (GSH) content and higher level of malondialdehyde (MDA) in hepatic and renal tissues as compared with normal rats. The activities of all parameters were found to be increased, except MDA in ginger-treated diabetic rats, in hepatic and renal tissues. Ginger supplementation, for 30 days to diabetic rats, resulted in significant dose-dependent hypoglycaemic and antioxidant activities. These findings suggest that ginger treatment exerts a therapeutic protective effect in diabetes by decreasing oxidative stress, and hepatic and renal damage.     

Particle migration of concentrated suspension flow in bifurcating channels

Flow of suspension in bifurcating channels has extensive applications in industrial and natural settings. A phenomenon of particular interest during the flow of concentrated suspension is shear-induced particle migration. Previous works on suspension transport in branched channels have been limited to dilute flow conditions. We have carried out experiments using the Particle Image Velocimetry (PIV) technique to study concentrated suspension transport in asymmetric T- and symmetric Y-shape channels. Numerical simulations of fluid flow and particle transport equations were also carried out for the same geometry which was used in the experiments. The migration and transport of particles in the simulations were studied using the Diffusive Flux Model. We have observed in both experiments and numerical simulations that due to the shear-induced migration phenomena the particles move towards the center of the channel, and this gives rise to the blunting of velocity profile before the junction. After the bifurcation, the peak of velocity profile moves in the direction of the outer wall, whereas, the maxima in particle concentration was observed near the inner walls. This causes asymmetry in the velocity and concentration profiles in the daughter branches. As we move towards the downstream positions the maxima in velocity and concentration profiles again shifts toward the center of the channel. The results from the experiments and simulations are observed to be in good agreement.