Electrical transport and optical studies of ferromagnetic Cobalt doped ZnO nanoparticles exhibiting a metal-insulator transition

The observed correlation of oxygen vacancies and room temperature ferromagnetic ordering in Co doped ZnO1-o nanoparticles reported earlier (Naeem et al Nanotechnology 17, 2675-2680) has been further explored by transport and optical measurements. In these particles room temperature ferromagnetic ordering had been observed to occur only after annealing in forming gas. In the current work the optical properties have been studied by diffuse reflection spectroscopy in the UV-Vis region and the band gap of the Co doped compositions has been found to decrease with Co addition. Reflections minima are observed at the energies characteristic of Co+2 d-d (tethrahedral symmetry) crystal field transitions, further establishing the presence of Co in substitutional sites. Electrical transport measurements on palletized samples of the nanoparticles show that the effect of a forming gas is to strongly decrease the resistivity with increasing Co concentration. For the air annealed and non-ferromagnetic samples the variation in the resistivity as a function of Co content are opposite to those observed in the particles prepared in forming gas. The ferromagnetic samples exhibit an apparent change from insulator to metal with increasing temperatures for T>380K and this change becomes more pronounced with increasing Co content. The magnetic and resistive behaviors are correlated by considering the model by Calderon et al [M. J. Calderon and S. D. Sarma, Annals of Physics 2007 (Accepted doi: 10.1016/j.aop.2007.01.010] where the ferromagnetism changes from being mediated by polarons in the low temperature insulating region to being mediated by the carriers released from the weakly bound states in the higher temperature metallic region.Comment: 7 pages, 6 figure

Bacteriological and immunological study associated with patients of Urinary Bladder carcinoma

The blood, serum & urine samples are collected from (22) patients with urinary bladder cancer were admitted to Al-Hilla general teaching hospital after diagnosis by helping urology physician. The result appeared that E.coli with high percentage (22.7% ,27.2%)in nixed &single infection respectively followed by Ps.aeuroginosa (22.7% , 13.6%) and S.aureus (18.8% , 9.09%).   Interleukin 2 &Interleukin 8 concentration level was detected in serum by enzyme-linked immunosorbent assay(ELISA) and data were compared with control to compare the performance of each cytokins & results show no elevated , no significant decrease in level  in two cytokins, this leads  to an independent factors for the detection of urinary bladder cancer

Detection P53, Rb1 and H-ras Loss of Heterozygosity LOH in Patients with Urinary Bladder carcinoma

In this study 22 samples of urine sediments were obtained from patients with Urinary Bladder Carcinoma, DNA base technique and LOH detection was investigated in three genes P53, Rb1 and H-ras. The result are shown that LOH was present in most cases and for all genes where LOH in P53 represents (31.8%) and for Rb1 (45.4%) and for H-ras gene (27.2%).In some cases, more than one gene locus mutations were found

Synthesis and Magnetic Properties of Cobalt Ferrite (CoFe2O4) Nanoparticles Prepared by Wet Chemical Route

Magnetic nanoparticles of cobalt ferrite have been synthesized by wet chemical method using stable ferric and cobalt salts with oleic acid as the surfactant. X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) confirmed the formation of single phase cobalt ferrite nanoparticles in the range 15-48nm depending on the annealing temperature and time. The size of the particles increases with annealing temperature and time while the coercivity goes through a maximum, peaking at around 28nm. A very large coercivity (10.5kOe) is observed on cooling down to 77K while typical blocking effects are observed below about 260K. The high field moment is observed to be small for smaller particles and approaches the bulk value for large particles.Comment: 18 pages, accepted in JMMM, (May, 2006

Decomposition of Continuity and Separation Axioms Via Lower and Upper Approximation

In this paper we study the rough set theory by defined the concepts of rough regularity and rough normality in the topological spaces which we can consider them as results from the general relations on the approximation spaces. Keywords: Topologized approximation space, rough regularity, rough normality, rough continuity, rough homeomorphism

Rough Probability In Topological Spaces

In this paper we study the rough probability in the topological spaces which we can consider them as results from the general relations on the approximation spaces. Keywords: Stochastic approximation space, rough expectation, rough variance, rough probability generating function, rough characteristic function.