A low-noise-figure 1.5 μm multiple-quantum-well opticalamplifier

The authors report on the noise characteristics of InGaAs/InGaAsP multiple-quantum-well optical amplifiers operating near 1.5 μm. A noise figure of 4.4 dB is reported, verifying the predicted low-noise properties of quantum-well amplifiers     

Study of Magnetic and Electrical Properties of Poly(o-phenylenediamine)/Manganese Substituted ZnFe2O4 Nanocomposites

Journal of Inorganic and Organometallic Polymers and Materials - Different concentrations of ZnFe2O4 and manganese substituted ZnFe2O4 nanoparticles (10%, 20% and 30%) dispersed...     

Kinetics of vinyl polymerization initiated by potassium permanganate/β-hydroxybutyric acid redox system

The aqueous polymerization of acrylamide initiated by potassium permanganate/β-hydroxybutyric acid has been studied volumetrically at 35 ± 0.01°C in an inert medium. The rate of polymerization shows nearly square root dependence on β-hydroxybutyric acid at low concentration (3.12 – 12.5 · 10^?3 mol dm^?3). The order with respect to potassium permanganate has been found to be 0.6 indicating thereby a bimolecular mode of termination. The polymerization rate has been varied linearly at low monomer concentrations i.e. from 2.5 –7.0 · 10^?2 mol dm^?3. The dependence of number average degree of polymerization on the initial rate of polymerization and temperature has been determined. The over-all activation energy has been found to be 51.66 kJ mol^?1. A kinetic reaction scheme is proposed on the basis of experimental results.     

Deposition of hydroxyapatite coatings by axial plasma spraying: Influence of feedstock characteristics on coating microstructure,phase content and mechanical properties

Axial plasma spray is one of the thermal spray techniques to deposit multifunctional advanced coatings. The present work explores the use of this process to deposit thin, continuous, and adherent Ca₅ (PO₄)₃OH (hydroxyapatite, HAp) coatings and characterize its microstructure, phases, hardness and adhesion strength. Three different suspension-deposited HAp coatings were investigated and compared with powder-deposited HAp coating on a Ti6Al4V substrate. The effect of mean solute particle size and solid-loading in the suspension has been explored on the evolution of microstructure, phase content and mechanical properties of axial suspension plasma sprayed (ASPS) coatings. Phase-characterization has shown retention of hydroxyapatite phase and coating crystallinity in the deposited coatings, whereas the adhesion strength of the HAp coating decreased from ～40 MPa to ～13 MPa when bioglass was added to the feedstock material. The lower solid load content and lower mean solute particle size in the suspension were found to be beneficial in achieving porous, rougher, and well-adhering coatings. This work concludes that ASPS can potentially deposit thin HAp coatings (< 50 μm) with high adhesion strength.     

Rigidity of a simple extended lower triangular matrix

For the all-ones lower triangular matrices, the upper and lower bounds on rigidity are known to match [P. Pudlak, Z. Vavrin, Computation of rigidity of order n²/r for one simple matrix, Comment Math. Univ. Carolin. 32 (2) (1991) 213-218]. In this short note, we apply these techniques to the all-ones extended lower triangular matrices, to obtain upper and lower bounds with a small gap between the two; we show that the rigidity is .     

Green synthesis of anisotropic gold nanoparticles using hordenine and their antibiofilm efficacy against Pseudomonas aeruginosa

Pseudomonas aeruginosa is a notorious pathogen that causes biofilm aided infections in patients with cystic fibrosis and burn wounds, resulting in significant mortality in immunocompromised individuals. This study reports a novel one‐step biosynthesis of gold nanoparticles using phytocompound, hordenine (HD), as a reducing and capping agent. The synthesis of the anisotropic hordenine‐fabricated gold nanoparticles (HD‐AuNPs) with an average particle size of 136.87 nm was achieved within 12 h of incubation at room temperature. Both HD and HD‐AuNPs exhibited significant antibiofilm activity against P. aeruginosa PAO1, although greater biofilm inhibition was observed for the nanoparticles as compared to hordenine alone. In the microtitre plate assay and tube method, the nanoparticles significantly inhibited the biofilm formation by 73.69 and 78.41%, respectively. The exopolysaccharide production by the test pathogen was arrested by 68.46% on treatment with the nanoparticles. Further, the effect of HD and HD‐AuNPs on the biofilm architecture of P. aeruginosa was revealed by light and confocal laser‐scanning microscopy micrographs. The overall results of this study suggested the synergistic antibiofilm effect of AuNPs and HD for the treatment of chronic bacterial infections caused by biofilms forming pathogens.Inspec keywords: molecular biophysics, biochemistry, gold, nanoparticles, nanofabrication, microorganisms, organic compounds, particle size, nanobiotechnologyOther keywords: green synthesis, anisotropic gold nanoparticles, hordenine, antibiofilm efficacy, Pseudomonas aeruginosa, pathogen, cystic fibrosis, burn wounds, one‐step biosynthesis, phytocompound, reducing agent, capping agent, particle size, microtitre plate assay, tube method, confocal laser‐scanning microscopy micrographs, Au     

Reliability Analysis of Mobile Ad Hoc Networks Using Universal Generating Function

The proliferation of the wireless network over the last decade is one of the significant drivers for the increased deployment of mobile ad hoc networks (MANETs) in the battle field. It is not practically possible to build a fixed wired network infrastructure in battle field. But it is possible to create a mobile wireless network infrastructure because of the mobility of the soldiers. MANET is justified by the possibility of building a network where no infrastructure exists. MANET with group communication applications and multicasting can highly benefit from a networking environment such as military and emergency uses. In such applications, the used ad hoc networks need to be reliable and secure. In recent years, a specific technique called the universal generating function technique (UGFT) has been applied to determine the network reliability. The UGFT is based on an approach that is closely connected to generating functions that are widely used in probability theory. This work devotes to assess the MANET reliability using the UGFT. Reliability of the MANET is defined as the probability that the transformed message from the source can be passed successfully through the MANET and reached the target without any delay. Two kinds of UGFs are discussed in this work, and an algorithm has been proposed to execute the system reliability. This UGFT is illustrated with a case study in a battlefield environment. Copyright © 2014 John Wiley & Sons, Ltd.