The effect of lateral interactions on the thermal desorption of N\u3csub\u3e2\u3c/sub\u3e from Ni(100)

We have investigated the desorption of N2 from Ni(100) using thermal desorption spectroscopy (TDS). A modified Polanyi-Wigner equation has been used to obtain the desorption energy and the preexponential factor, both of which depend on the coverage of the adsorbate. We show that there is a large lateral interaction among the adlayer molecules when N2 goes down as ordered c (2 X 2) on Ni. In addition, the overlayer ordering, in the thermal desorption process, is observed to affect the thermal desorption spectra

Antifungal Activity of Alcoholic Leaf Extracts of Terminalia Catappa and Terminalia Arjuna on Some Pathogenic and Allergenic Fungi

Abstract Ethanol and methanol leaf extracts of Terminalia catappa and Terminalia arjuna were investigated for in-vitro antifungal activity. Four fungi tested were Aspergillus niger, Alternaria alternata, Curvularia lunata and Trychophyton tonsurans.The in-vitro antifungal activity was evaluated by food poison technique. Both the plants should antifungal activity on comparision with T. arjuna better antifungal efficacy was shown by methanol extract of T. catappa. Methanol extract showed significant antifungal activity against most susceptible mould was Curvularia lunata. The results were compared with standard antifungals. Key words: Terminalia species, medicinal plants, antifungal activity, Aspergillus niger, Alternaria alternata, Curvularia lunata, Trychophyton tonsurans, pathogenic, allergenic in-vivo

Nano Pattern Formation and Surface Modifications by Ion Irradiation

Ion Irradiation is a technologically important technique to modify the surfaces. We have investigated the patterning of InP(111) surfaces by low energy (3 keV) as well as high energy (1.5 Mev) ion beams. After low energy ion irradiation, surfaces exhibit well defined nano dots which ripen at initial stages but exhibit fragmentations at high fluences. The surface rms, at both the energies, displays a similar behaviour of initially increasing with increasing fluences but decreasing for higher fluences. The studies show some common features at these low and high energies, like the smoothening of surface beyond the a/c transition.Defence Science Journal, 2009, 59(4), pp.413-426, DOI:http://dx.doi.org/10.14429/dsj.59.154

Estimation of serum 25 hydroxy vitamin D level and its correlation with metabolic and endocrine dysregulation in women with PCOS

Background: Polycystic ovarian syndrome is the most common hormonal disturbance in the reproductive age women, with prevalence of 5-10%. Vitamin D deficiency is common in women with or without PCOS. The aim of this study was to assess association of serum vitamin D level with metabolic and endocrine dysregulation in women with PCOS.Methods: This cross-sectional study was done over a period of one year. 100 women of age group 20-40 years were divided in group A 30 (BMI >30 mg/m2) with PCOS, group B 20 (BMI <25 mg/m2) with PCOS, group C 50 controls and were investigated for serum FSH, LH, LH/FSH ratio, S. total testosterone, S. postprandial insulin level, glucose insulin ratio, 25 hydroxy vitamin D level.Results: LH/FSH ratio >2 (33.33% in obese and 50% in non-obese), serum total testosterone level >0.8ng/ml (80% in obese and 75% in non-obese) (p value was significant between study group as well as between study and control group). Serum fasting, postprandial blood glucose, postprandial serum insulin level was elevated in obese than non-obese PCOS. 25 (OH) vitamin D deficiency <20 ng/ml (56.675% in obese and 45% in non-obese). So, vitamin D deficiency was more common in obese PCOS.Conclusions: PCOS is more common in age group of 20-40 years. There is more Insulin resistance in obese PCOS as compared to non-obese PCOS. Vitamin D deficiency is comparatively more common in obese PCOS population than in non-obese PCOS.

Nanoscale Defect Formation on InP(111) Surfaces after MeV Sb Implantation

We have studied the surface modifications as well as the surface roughness of the InP(111) surfaces after 1.5 MeV Sb ion implantations. Scanning Probe Microscope (SPM) has been utilized to investigate the ion implanted InP(111) surfaces. We observe the formation of nanoscale defect structures on the InP surface. The density, height and size of the nanostructures have been investigated here as a function of ion fluence. The rms surface roughness, of the ion implanted InP surfaces, demonstrates two varied behaviors as a function of Sb ion fluence. Initially, the roughness increases with increasing fluence. However, after a critical fluence the roughness decreases with increasing fluence. We have further applied the technique of Raman scattering to investigate the implantation induced modifications and disorder in InP. Raman Scattering results demonstrate that at the critical fluence, where the decrease in surface roughness occurs, InP lattice becomes amorphous.Comment: 18 pages, 9 figure

Synchrotron radiation induced chemical vapor deposition of thin films from metal hexacarbonyls*

We have studied the initial stages of synchrotron radiation [SR] induced chemical vapor deposition [CVD] of metal-containing thin films from metal hexacarbonyl gases. We have measured the dependence of the initial deposition rate upon gas pressure at room temperature. Substrates were exposed to SR for single fills of the electron storage ring at constant pressure of Mo(CO)6, Cr(CO)6, or W(CO) 6 gas. Deposition was monitored in situ by Auger electron spectroscopy using the SW as the excitation source. The presence of metal, carbon, and oxygen in the deposited films was observed, and the results are consistent with previous studies. Deposition was found to be isolated to areas of the substrate exposed to the SR beam. We discuss these results as they relate to the use of SR as a means to induce GVD and the possibility of patterned deposition using a masked SR source

Probing Gauge String Formation in a Superconducting Phase Transition

Superconductors are the only experimentally accessible systems with spontaneously broken gauge symmetries which support topologically nontrivial defects, namely string defects. We propose two experiments whose aim is the observation of the dense network of these strings thought to arise, via the Kibble mechanism, in the course of a spontaneous symmetry breaking phase transition. We suggest ways to estimate the order of magnitude of the density of flux tubes produced in the phase transition. This may provide an experimental check for the theories of the production of topological defects in a spontaneously broken gauge theory, such as those employed in the context of the early Universe.Comment: 16 pages (Latex), 4 figures included, change in title, some minor changes, published versio