Electrical and Optical Characterisation of 100 MeV 197Au Irradiated GaAs.

Effect of 100 MeV 197Au implantation, followed by Rapid Thermal Annealing on electrical and optical characteristic is reported. Single crystal n+ GaAs substrates of orientation have been implanted at room temperature with 197Au ions to the doses of 1X1012, 1X1013, 1X1014 ions/cm2. The as-implanted current-voltage (I-V) characteristic of samples is studied and the optical investigations in IR and mid IR-range have been made. The implanted samples were isochronally annealed by RTA system at different temperatures and the room temperature electrical characterization and the optical investigations are reported

Using level-2 fuzzy sets to combine uncertainty and imprecision in fuzzy regions

In many applications, spatial data need to be considered but are prone to uncertainty or imprecision. A fuzzy region - a fuzzy set over a two dimensional domain - allows the representation of such imperfect spatial data. In the original model, points of the fuzzy region where treated independently, making it impossible to model regions where groups of points should be considered as one basic element or subregion. A first extension overcame this, but required points within a group to have the same membership grade. In this contribution, we will extend this further, allowing a fuzzy region to contain subregions in which not all points have the same membership grades. The concept can be used as an underlying model in spatial applications, e.g. websites showing maps and requiring representation of imprecise features or websites with routing functions needing to handle concepts as walking distance or closeby

Proton-Induced X-ray Emission (PIXE) Analysis and DNA-chain Break study in rat hepatocarcinogenesis: A possible chemopreventive role by combined supplementation of vanadium and beta-carotene

Combined effect of vanadium and beta-carotene on rat liver DNA-chain break and Proton induced X-ray emission (PIXE) analysis was studied during a necrogenic dose (200 mg/kg of body weight) of Diethyl Nitrosamine (DENA) induced rat liver carcinogenesis. Morphological and histopathological changes were observed as an end point biomarker. Supplementation of vanadium (0.5 ppm ad libitum) in drinking water and beta-carotene in the basal diet (120 mg/Kg of body weight) were performed four weeks before DENA treatment and continued till the end of the experiment (16 weeks). PIXE analysis revealed the restoration of near normal value of zinc, copper, and iron, which were substantially altered when compared to carcinogen treated groups. Supplementation of both vanadium and beta-carotene four weeks before DENA injection was found to offer significant (64.73%, P < 0.001) protection against generation of single-strand breaks when compared with the carcinogen control counter parts. A significant stabilization of hepatic architecture of the cells was observed as compared to carcinogen control in vanadium plus beta-carotene treated group. This study thus suggests that vanadium, a prooxidant but potential therapeutic agent yield safe and effective pharmacological formulation with beta-carotene, an antioxidant, in the inhibition of experimental rat hepatocarcinogenesis

Prevalence and component analysis of metabolic syndrome: An Indian atherosclerosis research study perspective

Asian Indians have a high predisposition to metabolic syndrome (MS) and coronary artery disease (CAD). The present study aimed to estimate MS prevalence in 531 Asian Indian families comprising of 2318 individuals. Anthropometrics and lipid profile were assessed. MS prevalence was estimated using standard Adult Treatment Panel III (ATP-III) and World Health Organisation (WHO) criteria and modified definitions which included lowered cut-offs for waist circumference (WC) (≥90 cm for men and ≥80 cm for women], body mass index (BMI) (≥23 kg/m2) and impaired fasting glucose (IFG) levels. ATP-III criteria identified a significantly higher proportion of people with MS (N = 933; 40.3%) compared with WHO (N = 708; 30.6%; p < 0.0001) while modified ATP-III showed maximum gain in percent prevalence among the revised criteria (17.3%; p = 0.0056). The IDF criteria identified similar proportion of subjects with MS (N = 809; 34.9%) as the revised WHO criteria (N = 792; 34.2%). The number of MS subjects was highest in the 50–59 years age group. MS was diagnosed a decade earlier in unaffected subjects compared with those with CAD/diabetes using the modified MS criteria. WC correlated significantly with BMI and waist–hip ratio (WHR) (p = 0.000). Among MS components, high density lipoprotein cholesterol and BMI contributed significantly in males (71.4% and 85.9%) and females (86.8% and 88.8%), respectively. The higher percentage contribution of WC among males and WHR among females indicates the influence of gynecoid/android pelvis on WHR measures. In conclusion, the revision of definition criteria for MS with lowered cut-offs for WC and BMI is critical for the accurate assessment of MS among Asian Indians

Properties of silicon dioxide layers with embedded metal nanocrystals produced by oxidation of Si:Me mixture

A two-dimensional layers of metal (Me) nanocrystals embedded in SiO2 were produced by pulsed laser deposition of uniformly mixed Si:Me film followed by its furnace oxidation and rapid thermal annealing. The kinetics of the film oxidation and the structural properties of the prepared samples were investigated by Rutherford backscattering spectrometry, and transmission electron microscopy, respectively. The electrical properties of the selected SiO2:Me nanocomposite films were evaluated by measuring C-V and I-V characteristics on a metal-oxide-semiconductor stack. It is found that Me segregation induced by Si:Me mixture oxidation results in the formation of a high density of Me and silicide nanocrystals in thin film SiO2 matrix. Strong evidence of oxidation temperature as well as impurity type effect on the charge storage in crystalline Me-nanodot layer is demonstrated by the hysteresis behavior of the high-frequency C-V curves

Resonance phenomena in ultracold dipole-dipole scattering

Elastic scattering resonances occurring in ultracold collisions of either bosonic or fermionic polar molecules are investigated. The Born-Oppenheimer adiabatic representation of the two-bodydynamics provides both a qualitative classification scheme and a quantitative WKB quantization condition that predicts several sequences of resonant states. It is found that the near-threshold energy dependence of ultracold collision cross sections varies significantly with the particle exchange symmetry, with bosonic systems showing much smoother energy variations than their fermionic counterparts. Resonant variations of the angular distributions in ultracold collisions are also described.Comment: 19 pages, 6 figures, revtex4, submitted to J. Phys.