A circularly polarized printed elliptical wide-slot antenna with high bandwidth-dimension-ratio for wireless applications

Wireless Networks - This paper outlines a simple design of a compact wideband microstrip-line fed antenna having two rotated elliptical wide-slots (EWSs). Here, both the elliptical wide-slots are...     

Analytical modeling of bidirectional multi‐channel IEEE 802.11 MAC protocols

This paper presents an analytical approach to model the bi‐directional multi‐channel IEEE 802.11 MAC protocols (Bi‐MCMAC) for ad hoc networks. Extensive simulation work has been done for the performance evaluation of IEEE 802.11 MAC protocols. Since simulation has several limitations, this work is primarily based on the analytical approach. The objective of this paper is to show analytically the performance advantages of Bi‐MCMAC protocol over the classical IEEE 802.11 MAC protocol. The distributed coordination function (DCF) mode of medium access control (MAC) is considered in the modeling. Two different channel scheduling strategies, namely, random channel selection and fastest channel first selection strategy are also presented in the presence of multiple channels with different transmission rates. M/G/1 queue is used to model the protocols, and stochastic reward nets (SRNs) are employed as a modeling technique as it readily captures the synchronization between events in the DCF mode of access. The average system throughput, mean delay, and server utilization of each MAC protocol are evaluated using the SRN formalism. We also validate our analytical model by comparison with simulation results. The results obtained through the analytical modeling approach illustrate the performance advantages of Bi‐MCMAC protocols with the fastest channel first scheduling strategy over the classical IEEE 802.11 protocol for TCP traffic in wireless ad hoc networks. Copyright © 2010 John Wiley & Sons, Ltd.     

Determination of Solvent Contamination and Characterization of Ultrafine HNS Particles after Solvent Recrystallization

Solvent–antisolvent recrystallization employed for size reduction of HNS has been described and the effect of various parameters such as stirring rate, effect of antisolvent type, antisolvent temperature, ultrasonication, etc. was investigated. Purified HNS, produced by hot solvent recrystallization of production grade crude HNS, of mean particle size ∼95 μm was used for preparation of ultrafine particles of HNS. Solvent contamination in terms of residual solvent was determined by ¹H NMR and GC‐MS analysis. In addition, ultrafine HNS has been characterized for purity (HPLC, ¹H NMR), particle size and shape (PSA and SEM), specific surface area (BET analysis), thermal behavior (TGA, DSC), sensitivity (impact, friction), etc. The results have been compared with C‐HNS. UF‐HNS was >99% pure with mean particle size <1 μm. SEM showed submicrometer size rods like particles of HNS as the final material.     

A Bayesian game model and network availability model for small cells under denial of service (DoS) attack in 5G wireless communication network

Wireless Networks - Nowadays small cells have become the integral part of 5G wireless communication network (WCN). However, the incorporation of small cells in 5G WCN creates chances for attackers...     

Development and Evaluation of Hybrid Artificial Neural Network Architectures for Modeling Spatio-Temporal Groundwater Fluctuations in a Complex Aquifer System

Water Resources Management - The proper design, development, and appropriate tuning of the Hybrid Neural Network architecture, mainly for its parsimoniousity and optimal training can help...     

A Novel Approach based on Average Information Parameters for Investigation and Diagnosis of Lung Cancer using ANN

In this paper, an average informational parameter based approach for lung cancer detection and diagnosis has been proposed. Suggested methodology is established on average information parameters by utilizing image processing tools for lung cancer investigation. The real issue with the lung cancer diseases is the time constraint for physical diagnosis that expands the death possibilities. Henceforth essentially proposed technique is an approach that would help the medical practitioners for precise and superior decision against the lung cancer discovery. The crucial point in the proposed method is that it helps the doctors for taking a firm decision on lung cancer diagnosis. Microscopic lung images are taken for analysis and investigation by using digital image processing techniques which also recovers the quality of images that has been degraded by several reasons including random noise. The statistical parameters are implemented for lung cancer analysis. The statistical and mathematical parameters are implemented like Entropy, Standard Deviation, Mean, Variance and MSE under average information method. The statistical range of each parameter is calculated for number of iterations. The individual statistical parameter analysis with its impact on lung cancer images is carried out and finally the Artificial Neural Network is the final decision maker in lung cancer diagnosis. This paper also rejects the null hypothesis test by implementing one of the standard statistical methods.     

Transition Metal Ion–Mediated Tyrosine‐Based Short‐Peptide Amphiphile Nanostructures Inhibit Bacterial Growth

We report the design and synthesis of a biocompatible small‐peptide‐based compound for the controlled and targeted delivery of encapsulated bioactive metal ions through transformation of the internal nanostructures of its complexes. A tyrosine‐based short‐peptide amphiphile (sPA) was synthesized and observed to self‐assemble into β‐sheet‐like secondary structures. The self‐assembly of the designed sPA was modulated by application of different bioactive transition‐metal ions, as was confirmed by spectroscopic and microscopic techniques. These bioactive metal‐ion‐conjugated sPA hybrid structures were further used to develop antibacterial materials. As a result of the excellent antibacterial activity of zinc ions the growth of clinically relevant bacteria such as Escherichia coli was inhibited in the presence of zinc ? sPA conjugate. Bacterial testing demonstrated that, due to high biocompatibility with bacterial cells, the designed sPA acted as a metal ion delivery agent and might therefore show great potential in locally addressing bacterial infections.     

Glycolytic depolymerization of PET waste using MP-diol and utilization of recycled product for UV-curable wood coating

Polyethylene terephthalate (PET) waste recycling has become a worldwide research interest for industries and academic institutes due its inevitable environmental impact. The main objective of current research work is to target efficient recycling of PET waste from mineral water bottles by the glycolysis method and subsequent use of the recycled product for value-added coating application. In the present study, we report on MP-diol (2-methyl-1,3-propanediol) which is not explored much for the chemical recycling of PET, having a branched aliphatic diol with two primary hydroxyls, for glycolysis reaction. The reaction parameters were optimized for microwave-assisted technique by varying the ratio of raw materials, reaction time, temperature, and power. The reaction parameters were optimized, and the recycled oligomeric product (OPETMPD) was separated, purified, and characterized by chemical and spectroscopic methods. Subsequently, dimethacrylated oligoesters of PET oligomer (UV oligomer) were synthesized by methacrylation of the glycolyzed PET product (OPETMPD). The synthesized UV oligomer was evaluated using chemical and spectroscopic methods. Ultraviolet (UV) radiation-curable formulations were prepared using synthesized UV oligomer and applied on wooden panels. The coatings were cured using UV-curing machine and evaluated for their performance properties. The partial replacement of UV oligomer in UV formulations exhibited comparative coating performance properties with respect to conventional UV formulation.     

Detection of single photoluminescent diamond nanoparticles in cells and study of the internalization pathway

Diamond nanoparticles are promising photoluminescent probes for tracking intracellular processes, due to embedded, perfectly photostable color centers. In this work, the spontaneous internalization of such nanoparticles (diameter 25 nm) in HeLa cancer cells is investigated by confocal microscopy and time-resolved techniques. Nanoparticles are observed inside the cell cytoplasm at the single-particle and single-color-center level, assessed by time-correlation intensity measurements. Improvement of the nanoparticle signal-to-noise ratio inside the cell is achieved using a pulsed-excitation laser and time-resolved detection taking advantage of the long radiative lifetime of the color-center excited state as compared to cell autofluorescence. The internalization pathways are also investigated, with endosomal marking and colocalization analyses. The low colocalization ratio observed proves that nanodiamonds are not trapped in endosomes, a promising result in prospect of drug delivery by these nanoparticles. Low cytotoxicity of these nanoparticles in this cell line is also shown.     

Development and comparative anti-microbial evaluation of lipid nanoparticles and nanoemulsion of Polymyxin B

Polymyxin B is a decapeptide, mainly used for the treatment of gram-negative bacteremia. It was anticipated that a prolongation of release may lead to a more efficacious therapy. Lipid nanoparticles and nanoemulsion were formulated and comparatively evaluated for their properties. Lipid nanoparticles of Polymyxin B Sulphate with a mean particle size of 186.9 nm (Polydispersity Index 0.235) were prepared by nano-precipitation technique and nanoemulsion was prepared under the conditions of spontaneous formation with a mean globule size 125.0 nm (Polydispersity Index 0.291). The lipid nanoparticles were screened for lipid load from 0.1-1% along with 1-10% surfactant while in the optimization of nanoemulsion different ratios of oil, surfactant, and co-surfactant were evaluated. The developed systems were taken up for comparative anti-microbial study against a sensitive strain of E. coil using Turbidimetry as the method for monitoring the growth of microorganisms in a time dependent manner. Results of the study using ANOVA revealed an initial comparable activity with no statistical difference between the free drug, lipid nanoparticles, and the nanoemulsion. The anti-microbial effect was significantly sustained by lipid nanoparticles over a period of 18 hr but could not be sustained in case of nanoemulsion after 12 hr. Further, in order to assess anti-microbial activity of the developed delivery templates, a similar study was carried out using the lipid nanoparticles and nanoemulsion without the incorporation of drug. The results showed only a mild anti-microbial action for drug-free lipid nanoparticles but significant activity was exerted by drug-free nanoemulsion against plain drug throughout the study. It was concluded that the developed lipid nanoparticles and nanoemulsion are promising delivery vectors for the anti-microbial drugs. Further, lipid nanoparticles could give an initial as well as sustained effect while the nanoemulsion was capable of exerting potent effect for a shorter period of time.