Oblique propagation of arbitrary amplitude electron acoustic solitary waves in magnetized kappa-distributed plasmas

The linear and nonlinear properties of large amplitude electron-acoustic waves are investigated in a magnetized plasma comprising two distinct electron populations (hot and cold) and immobile ions. The hot electrons are assumed to be in a non-Maxwellian state, characterized by an excess of superthermal particles, here modelled by a kappa-type long-tailed distribution function. Waves are assumed to propagate obliquely to the ambient magnetic field. Two types of electrostatic modes are shown to exist in the linear regime, and their properties are briefly analyzed. A nonlinear pseudopotential type analysis reveals the existence of large amplitude electrostatic solitary waves and allows for an investigation of their propagation characteristics and existence domain, in terms of the soliton speed (Mach number). The effects of the key plasma configuration parameters, namely, the superthermality index and the cold electron density, on the soliton characteristics and existence domain, are studied. The role of obliqueness and magnetic field are discussed.Comment: Submitted to Plasma Physics and Controlled Fusio

Optoelectronic and antimicrobial activity of composite zinc oxide and cadmium sulphide quantum dots and application in water treatment

In the present study, we report the synthesis of composite zinc oxide and cadmium sulphidenanoparticles by a chemical route. ZnO–CdS nanocomposites have been gaining much importance as they show fascinating opto-electronic properties such as tunable band gap and the nanomaterials are suitable for fast photon absorption, transportation and collection. The prepared composite nanoparticles have been characterized by UV–VIS absorption, X-ray diffraction (XRD) and TEM, AFM and FTIR observation. UV-VIS optical spectroscopy study has been carried out to determine the band gap of the composite zinc oxide and cadmium sulphide thin film and it shows a blue shift with respect to the bulk value. The nanocomposites show enhanced optio -electronic properties compared to the individual constituents. The band gap of CdS–ZnO nanocomposites depend on various experimental parameters such as reaction time, concentrations of cadmium salt, and also chemical nature of the cadmium salt. The band gap value of the ZnO–CdS nanocrystalline films are obtained in the range of 3.88–4.14 eV which is higher than that of bulk value of ZnO (3.3 eV) and CdS (2.42 eV). The synthesized nanoparticles exhibited high antibacterial activity and can be used for water purification

Perinatal mortality necropsy findings 1957-1966

The 243 perinatal postmortem examinations carried out at St. Luke's Hospital Malta during the ten year period 1957-1966 are analysed and classified according to the International classification introduced by Butler and Bonham (1963). The series is compared with that of Butler and Bonham and explanations are offered for some of the divergent findings. Congenital malformations which accounted for 15.2% of all perinatal deaths, are analysed in some detail. Finally, figures indicate that in the more recent years, the number of perinatal deaths has decreased, whereas the number of necropsies has increased.peer-reviewe

Charged black holes in Vaidya backgrounds: Hawking's Radiation

In this paper we propose a class of embedded solutions of Einstein's field equations describing non-rotating Reissner-Nordstrom-Vaidya and rotating Kerr-Newman-Vaidya black holes.Comment: 30 pages, latex file, no figure

Antimicrobial activities of grape (Vitis vinifera L.) pomace polyphenols as a source of naturally occurring bioactive components

Grape pomace is a potential source of winery by-products having useful bioactive components. Antimicrobial activities of enzyme-assisted grape pomace polyphenols (GPP) were assessed against Escherichia coli IFO 3301 and Staphylococcus aureus IFO 12732 using plate count and spectrophotometry assays. GPP have shown credential growth inhibition against E. coli and S. aureus, respectively. The higher growth inhibition was mediated by the higher GPP concentrations against both E. coli and S. aureus, which implies dose dependency. GPP also exhibited bactericidal effects against both the Gram-positive and Gram-negative bacteria, whereas, Gram-positive bacteria have shown more susceptibility than Gram-negative bacteria. It is revealed that GPP is a potential source of natural antimicrobial agents.Keywords: Grape pomace, polyphenols, antimicrobial activity

Structure of vasa deferentia and spermatophores in Parapenaeopsis stylifera (H. Milne Edwards) (Decapoda: Penaeidae)

The structure of vasa deferentia and spermatophores has been described in Parapenaeopsis stylifera. The male reproductive system consists of two symmetrical halves; each half bears testis, vas deferens and an ejaculatory duct. Each testis comprised of two to three short, broad and milky white lobes; vas deferens is divisible into proximal, medial and distal parts. The proximal vas deferens (PVD) is a convoluted mass made up of an extremely long and thin tube having elongated rod like spermatozoa. The median vas deferens (MVD) is broad, straight, somewhat flattened and bears many membranous folds internally and contained complete spermatophores; the distal vas deferens (DVD) is straight and cylindrical tube. The ejaculatory duct is a simple dilation with a tubular basal part tapered posteriorly for extrusion of spermatophores. The spermatophores are minute, spindle shaped bodies present in large numbers in each ejaculatory duct; the size varied from 0.148 to 0.161 mm; each spermatophore bears six to eight rows of regularly arranged spermatozoa. Histological studies reveal no internal partitioning of either vas deferens or ejaculatory duct.Keywords: Parapenaeopsis stylifer, vasa deferentia, spermatophore

MHD Stagnation-Point Flow of a Nanofluid with Heat and Mass Transfer in the Presence of Thermal Radiation

The steady two-dimensional magnetohydrodynamics stagnation point flow of a nanofluid with radiation effect is investigated. Using a similarity transformation, the governing partial differential equations are reduced to ordinary differential equations. The transformed equations are solved numerically for three types of nanoparticles, namely copper (Cu), alumina (Al2O3), and titania (TiO2) by using shooting method. The features of the flow with heat and mass transfer characteristics for different values of governing parameters are analyzed and discussed. Comparison with published results is presented and it found to be in good agreement. Key Words: Nanofluid, Heat and Mass Transfer, Thermal Radiation, Stagnation-Point Flo

Genetic diversity at the FMR1 locus in the Indonesian population

We report an analysis of allelic diversity at short tandem repeat polymorphisms within the fragile XA locus in 1069 male volunteers from twelve Indonesian sub-populations. An odd numbered allele of DXS548 was found at high frequency in all Indonesian populations. Greater allelic diversity was identified at the loci under study than has been previously reported for an Asian population. These differences distinguish the Indonesian population from all previously reported Asian, European and African populations. A high frequency of small premutation alleles, 4/120 (3.3%, 95% CI 0.9–8.3%), was identified in the Moluccan population of Hiri Island