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

Electrical and Optical Characterisation of 100 MeV 197Au Irradiated GaAs

Effect of 100 MeV 197Au implantation, followedby Rapid Thermal Annealing on electrical and opticalcharacteristic is reported. Single crystal n+ GaAssubstrates of orientation have been implanted atroom 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 opticalinvestigations in IR and mid IR-range have been made.The implanted samples were isochronally annealed byRTA system at different temperatures and the roomtemperature electrical characterization and the opticalinvestigations are reported

Evaluation of nephroprotective effect of Bryonia lacinosa on streptozotocin induced diabetic nephropathy in rats

Background: Ayurvedic literature indicated use of Bryonia laciniosa (BL) for metabolic abnormalities. However only one study evaluated Bryonia laciniosa seed ethanolic extract in streptozotocin-induced diabetes in rats and was found to have anti-hyperglycemic and anti-hyperlipidemic effects. The authors looked at the renal function test in addition and found that it prevents deterioration of renal function in rats. Hence it was interesting to find if Bryonia laciniosa had any protective action in streptozotocin induced diabetic nephropathy in rats.Methods: Streptozotocin induced diabetic nephropathy model in wistar rats was standardised in phase 1. In phase 2 animals were divided into 4 groups and diabetic nephropathy was induce with STZ. Vehicle Control group animals received CMC 0.5%, Positive control group received enalapril 5 mg/kg, Test group 1 received ethanolic extract of Bryonia laciniosa (EEBL) 250 mg/kg and Test group 2 received (EEBL) 500 mg/kg from 3rd day onwards till 6 weeks. Renal function, morphology and histopthological changes were evaluated.Results: There was a significant reduction (p <0.001) in the serum creatinine and BUN in both low and high dose EEBL groups. High dose of EEBL lowered raised MDA values significantly (p<0.001) and raised the GSH values (p<0.001). On histopathology, the high dose EEBL reversed nephropathic changes which were equivalent to enalapril.Conclusions: Bryonia lacinosa in high doses 500 mg/kg has potential to reverse diabetic nephropathic changes induced in wistar rats

Pulsed laser treatment at Fe/C<SUB>6</SUB>H<SUB>6</SUB> interface: a Mossbauer effect study

The pulsed ruby laser induced reactive-quenching process at Fe/C6H6 Ibenzenel has been investigated using conversion electron Mossbauer spectroscopy [CEMS]. It is shown that iron carbide phases can be synthesized when an iron foil immersed in benzene is treated with ruby Laser pulses [&#955;=694 nm, pulse width ~30 ns, energy density =15 J/cm2]. The results indicate the formation of &#949;-carbide and Fe5C2 phases in the as-treated sample and its transformation to Fe3C upon thermal treatment. The result of the CEMS measurements are supported by small angle X-ray diffractometry

Intense blue-emitting Ca5Al8O14 : Eu phosphor for mercury free lamp

The calcium aluminates doped with Eu ions, Ca5Al8O14 : Eu, phosphors are prepared by the combustion method. The formation of crystalline aluminates was confirmed by X-ray diffraction pattern. The prepared phosphors were characterized by SEM, TGA, DTA, particle size analyzer and Photoluminescence (PL) techniques. From the UV-excited luminescence spectra it was found that the Eu ions acts as a luminescent centre with luminescence at the blue (λmax = 470 nm) region due to 4f 65d1 → 4f 7 transition. The excitation spectra show the broad band at 355 nm wavelength (λem = 470 nm). The excitation 355 nm is a mercury free excitation and therefore Ca5Al8O14 : Eu may be useful for the solid state lighting phosphor in lamp industry.Intense blue-emitting Ca5Al8O14 : Eu phosphor for mercury free lamp Abhay D Deshmukh1*, S J Dhoble1, S V Godbole2, M K Bhide2 and D R Peshwe3 1Kamla Nehru College, Sakkardara Square, Nagpur-440 009, Maharashtra, India 2Spectroscopy Section, Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai-400 085, India 3Department of Metallurgical and Materials Engineering, VNIT, Nagpur-440 011, Maharashtra, India E-mail : [email protected] Nehru College, Sakkardara Square, Nagpur-440 009, Maharashtra, India 2Spectroscopy Section, Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai-400 085, India 3Department of Metallurgical and Materials Engineering, VNIT, Nagpur-440 011, Maharashtra, Indi

Fe/Co Alloys for the Catalytic Chemical Vapor Deposition Synthesis of Single- and Double-Walled Carbon Nanotubes (CNTs). 1. The CNT−Fe/Co−MgO System

Mg0.90FexCoyO (x + y ) 0.1) solid solutions were synthesized by the ureic combustion route. Upon reduction at 1000 °C in H2-CH4 of these powders, Fe/Co alloy nanoparticles are formed, which are involved in the formation of carbon nanotubes, which are mostly single and double walled, with an average diameter close to 2.5 nm. Characterizations of the materials are performed using 57Fe Mo¨ssbauer spectroscopy and electron microscopy, and a well-established macroscopic method, based on specific-surface-area measurements, was applied to quantify the carbon quality and the nanotubes quantity. A detailed investigation of the Fe/Co alloys’ formation and composition is reported. An increasing fraction of Co2+ ions hinders the dissolution of iron in the MgO lattice and favors the formation of MgFe2O4-like particles in the oxide powders. Upon reduction, these particles form R-Fe/Co particles with a size and composition (close to Fe0.50Co0.50) adequate for the increased production of carbon nanotubes. However, larger particles are also produced resulting in the formation of undesirable carbon species. The highest CNT quantity and carbon quality are eventually obtained upon reduction of the iron-free Mg0.90Co0.10O solid solution, in the absence of clusters of metal ions in the starting material. Introduction Catalyti

Carbon Nanotubes by a CVD Method. Part II: Formation of Nanotubes from (Mg, Fe)O Catalysts

The aim of this paper is to study the formation of carbon nanotubes (CNTs) from different Fe/MgO oxide powders that were prepared by combustion synthesis and characterized in detail in a companion paper. Depending on the synthesis conditions, several iron species are present in the starting oxides including Fe2+ ions, octahedral Fe3+ ions, Fe3+ clusters, and MgFe2O4-like nanoparticles. Upon reduction during heating at 5 °C/min up to 1000 °C in H2/CH4 of the oxide powders, the octahedral Fe3+ ions tend to form Fe2+ ions, which are not likely to be reduced to metallic iron whereas the MgFe2O4-like particles are directly reduced to metallic iron. The reduced phases are R-Fe, Fe3C, and ç-Fe-C. Fe3C appears as the postreaction phase involved in the formation of carbon filaments (CNTs and thick carbon nanofibers). Thick carbon nanofibers are formed from catalyst particles originating from poorly dispersed species (Fe3+ clusters and MgFe2O4-like particles). The nanofiber outer diameter is determined by the particle size. The reduction of the iron ions and clusters that are well dispersed in the MgO lattice leads to small catalytic particles (<5 nm), which tend to form SWNTS and DWNTs with an inner diameter close to 2 nm. Well-dispersed MgFe2O4-like particles can also be reduced to small metal particles with a narrow size distribution, producing SWNTs and DWNTs. The present results will help in tailoring oxide precursors for the controlled formation of CNTs