Influence of microwave power on the preparation of NiO nanoflakes for enhanced magnetic and supercapacitor applications.

Nanoflake-structured NiO were synthesized by a microwave assisted method without the use of additives. The cubic phase of NiO nanoparticles with increasing crystalline nature for higher microwave power is ascertained by X-ray diffraction studies. Previous reports revealed that hexagonally structured ß-Ni(OH)2 was completely transferred into the cubic phase of NiO around 350 °C, confirmed by using thermal analysis (TG/DTA). In our present work, the size and morphology of nanoparticles are ascertained from transmission electron microscopy (TEM) analysis. Flake-like morphology with uniform size, shape and less agglomerated structure formation is obtained for 900 and 600 W of microwave power used for the synthesis of NiO samples. The effect of microwave power used for the synthesis of NiO nanoflakes was analyzed by studying the magnetic and electrochemical behavior of NiO nanoflakes. Room temperature magnetic measurements revealed the small ferromagnetic nature of NiO nanoparticles. It was observed that the samples synthesized at higher microwave power exhibited divergence behavior below 300 K in FC and ZFC measurements, which results superparamagnetic behavior. An enhanced supercapacitor performance with higher specific capacitance values was determined for NiO nanoflake samples synthesized at (25)600 W and 900 W of microwave power.

Role of solution pH on the microstructural properties of spin coated cobalt oxide thin films.

Cobalt Oxide (Co3o4) thin films have been successfully coated onto glass substrates at various solution pH by sol-gel spin coating technique. The film thickness was estimated using weight gain method and it revealed that the film thickness increased with solution pH values. The prepared film structural, morphological, optical and electrical properties were studied using X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis-NIR spectrophotometer and Vander Pau method, respectively. The structure of the films were found to be face centered cubic with preferential orientation along (311) plane. X-ray line profile analysis was used to evaluate the micro structural parameters such as crystallite size, micro strain, dislocation density and stacking fault probability. The crystallite size values are increased with increase of solution pH values and maximum value of crystallite is estimated at 40.8 nm at solution pH 8 +/- 0.1. Morphological results showed that the pH of the solution has a marked effect on morphology of the Co3O4 thin films. The optical studies revealed that the band gap can be tailored between 2.16 to 2.31 eV by altering pH. The thin film formed at a solution pH 7 is found to have a low resistivity and high mobility. The electrical resistivity (p), carrier concentration (n) and mobility (micro) values are 0.1 x 10(3) omega x cm, 8.9 cm2 gammas(-1) and 6.6 x 10(14) cm(-3), respectively for Co3O4 thin film prepared at solution pH 7 +/- 0.1. EDAX studies showed that the cobalt content increased and the oxygen content decreased with increase of pH.

Variation of microstructural and optical properties in SILAR grown ZnO thin films by thermal treatment.

The influence of thermal treatment on the structural and morphological properties of the ZnO films deposited by double dip Successive ionic layer by adsorption reaction is presented. The effect of annealing temperature and time in air ambient is presented in detail. The deposited films were annealed from 200 to 400 degrees C in air and the structural properties were determined as a function of annealing temperature by XRD. The studies revealed that films were exhibiting preferential orientation along (002) plane. The other structural parameters like the crystallite size (D), micro strain (epsilon), dislocation density (delta) and stacking fault (alpha) of as-deposited and annealed ZnO films were evaluated and reported. The optical properties were also studied and the band gap of the ZnO thins films varied from 3.27 to 3.04 eV with the annealing temperature. SEM studies revealed that the hexagonal shaped grains with uniformly distributed morphology in annealed ZnO thin films. It has been envisaged using EDX analysis that the near stoichiometric composition of the film can be attained by thermal treatment during which microstructural changes do occur.

Electrochemical and physical properties of electroplated CuO thin films.

Cupric oxide thin films have been prepared on ITO glass substrates from an aqueous electrolytic bath containing CuSO4 and tartaric acid. Growth mechanism has been analyzed using cyclic voltammetry. The role of pH on the structural, morphological, compositional, electrical and optical properties of CuO films is investigated. The structural studies revealed that the deposited films are polycrystalline in nature with a cubic structure. The preferential orientation of CuO thin films is found to be along (111) plane. X-ray line profile analysis has been carried out to determine the microstructural parameters of CuO thin films. The pyramid shaped grains are observed from SEM and AFM images. The optical band gap energy and electrical activation energy is found to be 1.45 and 0.37 eV, respectively. Also, the optical constants of CuO thin films such as refractive index (n), complex dielectric constant (epsilon) extinction coefficient (k) and optical conductivity (sigma) are evaluated.

SEM and AFM studies of dip-coated CuO nanofilms.

Cupric oxide (CuO) semiconducting thin films were prepared at various copper sulfate concentrations by dip coating. The copper sulfate concentration was varied to yield films of thicknesses in the range of 445-685 nm by surface profilometer. X-ray diffraction patterns revealed that the deposited films were polycrystalline in nature with monoclinic structure of (-111) plane. The surface morphology and topography of monoclinic-phase CuO thin films were examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Surface roughness profile was plotted using WSxM software and the estimated surface roughness was about ∼19.4 nm at 30 mM molar concentration. The nanosheets shaped grains were observed by SEM and AFM studies. The stoichiometric compound formation was observed at 30 mM copper sulfate concentration prepared film by EDX. The indirect band gap energy of CuO films was increased from 1.08 to 1.20 eV with the increase of copper sulfate concentrations.

Morphological properties of Ag2SeTe nano thin films prepared by thermal evaporation.

Semiconducting silver selenide telluride (Ag2SeTe) thin films were prepared with different thicknesses onto glass substrates at room temperature using thermal evaporation technique. The structural properties were determined as a function of thickness by X-ray diffraction exhibiting no preferential orientation along any plane; however, the films are found to have peaks corresponding to mixed phase. The morphology of these films was studied using scanning electron microscope and atomic force microscopy respectively, and is reported. The morphological properties are found to be very sensitive to the thin film thickness. The composition of the films is also estimated using energy dispersive analysis using X-rays and are also reported.

Morphology selection for cupric oxide thin films by electrodeposition.

Polycrystalline cupric oxide thin films were deposited using alkaline solution bath employing cathodic electrodeposition method. The thin films were electrodeposited at various solution pH. The surface morphology and elemental analyzes of the films were studied using scanning electron microscopy (SEM) and energy dispersive X-ray analysis, respectively. SEM studies revealed that the surface morphology could be tailored suitably by adjusting the pH value during deposition. Mesh average on multiple lattice mode atomic force microscopy image was obtained and reported.

Low temperature wet chemical synthesis of good optical quality vertically aligned crystalline ZnO nanorods.

The growth of ZnO nanorods on Au-coated ITO substrates using a low temperature wet chemical process is presented. Electron microscopy and x-ray diffraction observations reveal that the crystalline ZnO nanorods are preferentially oriented along the c axis. Room temperature photoluminescence (PL) measurements reveal a strong band edge emission at 382 nm, a signature of good crystallinity, with a weak and broad orange-red emission, which is typically attributed to the oxygen interstitials, in the range between 520 and 720 nm. Other than the second order feature of the band edge emission at 760 nm, no red or near-infrared bands are observed. The effect of precursor concentration on the morphological, structural and PL properties are studied, and the results are discussed.

Plasma vitrification and re-use of non-combustible fiber reinforced plastic, gill net and waste glass.

Fiber reinforced plastic (FRP) composite material has widespread use in general tank, special chemical tank and body of yacht, etc. The purpose of this study is directed towards the volume reduction of non-combustible FRP by thermal plasma and recycling of vitrified slag with specific procedures. In this study, we have employed three main wastes such as, FRP, gill net and waste glass. The thermal molten process was applied to treat vitrified slag at high temperatures whereas in the post-heat treatment vitrified slags were mixed with specific additive and ground into powder form and then heat treated at high temperatures. With a two-stage heat treatment, the treated sample was generated into four crystalline phases, cristobalite, albite, anorthite and wollastonite. Fine and relatively high dense structures with desirable properties were obtained for samples treated by the two-stage heating treatment. Good physical and mechanical properties were achieved after heat treatment, and this study reveals that our results could be comparable with the commercial products.

Anaesthetic management of a patient with pemphigus vulgaris for emergency laparotomy.

A 45-year-old man with a long-standing history of duodenal ulcer presented with symptoms and signs of perforation peritonitis. He also had lesions of pemphigus vulgaris throughout the body, involving both skin and mucous membranes. Care was taken to avoid pressure and friction during placement of monitoring devices, intravenous and arterial lines. Since the patient had to undergo exploratory laparotomy, intubation was performed in an atraumatic manner after rapid sequence induction. However, there was minor bleeding from the mucous lesions of the oral cavity, which was controlled by a saline adrenaline throat pack. The patient was extubated at the end of the surgery and steroids were continued in the peri-operative period.

Chemoprevention of oral leukoplakia with vitamin A and beta carotene: an assessment.

We conducted a double-blind placebo-controlled trial to evaluate the chemopreventive potential of either vitamin A alone or beta carotene alone in subjects with oral leukoplakia in Kerala, India. We randomised 160 fishermen and women with oral precancerous lesions to receive oral vitamin A (retinyl acetate 300,000 IU/week x 12 months, n = 50), or beta carotene (360 mg/week x 12 months, n = 55), or placebo (n = 55). Blood, saliva and urine samples were collected at baseline and at exit to study serum micronutrients and mutagenicity assays. Biopsies of the mucosal lesions at entry were performed for histopathological exclusion of malignancy. The subjects were examined once every 2 months to establish clinical response of lesions and toxicity, if any. The results are based on 43 complaint subjects on placebo, 42 on vitamin A and 46 on beta carotene. The complete regression rates were: 10% in the placebo arm, 52% with vitamin A and 33% with beta carotene (P < 0.0001). Homogeneous leukoplakias and smaller lesions responded better than non-homogeneous and larger lesions. No major toxicities were observed. Half of the responders with beta carotene and two thirds with vitamin A relapsed after stopping supplementation. Serum beta carotene concentration increased substantially with beta carotene administration while with vitamin A supplementation there was no change in serum retinol levels. In the vitamin A treated group there was a significant decrease in serum alpha tocopherol. Vitamin A administration resulted in a significant remission of oral leukoplakia without any side effects of prolonged vitamin A supplementation. The results of this study, as well as those from previous studies, appear to provide strong supporting evidence to justify long term trials with vitamin A in subjects with high-risk leukoplakias with oral cancer as an endpoint.

Studies on some trace and minor elements in blood. A survey of the Kalpakkam (India) population. Part I: Standardization of analytical methods using ICP-MS and AAS.

Blood is one of the widely used specimens for biological trace element research because of its biological significance and ease of sampling. We have conducted a study of the blood of the Kalpakkam township population for trace and minor elements. For this purpose, analytical methods have been developed and standardized in our laboratory for the elemental analysis of blood plasma and red cells. Inductively coupled plasma-mass spectrometry (ICP-MS), a relatively new technique, has been applied for the analysis of trace elements. Details regarding spectral interference and matrix interference encountered in the analysis of blood and the methods of correcting them have been discussed. Flame atomic absorption spectrometry (AAS)/atomic emission spectrometry (AES) has been applied for the determination of minor elements. Precision and accuracy of these methods have also been discussed.

Studies on some trace and minor elements in blood. A survey of the Kalpakkam (India) population. Part III: Studies on dietary intake and its correlation to blood levels.

In our studies on elemental levels in blood of the Kalpakkam population, it was found that the reference values for many elements were normal, but some deficiency with respect to Se was noticed. As a followup study, the dietary ingredients of the local population were analyzed for trace and minor elements to assess the dietary intake of these elements. Details of the analytical methods developed using the technique of inductively coupled plasma-mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) have been described. The dietary intake of many of these trace and minor elements were found to be quite adequate according to the recommended dietary allowance (RDA) levels prescribed, except for Se and Zn. The dietary intake of Se was found to be in the range 20-50 micrograms/d (as opposed to the RDA of 50-200 micrograms/d), whereas the intake of Zn was found to be in the range 8-10 mg/d (as opposed to the RDA of 15 mg/d). Although the deficiency of Se intake was reflected in the blood, that of Zn was not, probably owing to the high level of homeostasis for this element. Fish and egg were found to be rich sources of Se, followed by cereals and pulses, which were found to be the major sources of Zn.

Studies on some trace and minor elements in blood. A survey of the Kalpakkam (India) population. Part II: Reference values for plasma and red cell, and correlation with coronary risk index.

Since data on the trace element levels in Indian population are lacking, we chose to conduct a survey of the Kalpakkam township population. People in the age group 40-55 were included in this study. Reference values for trace and minor elements of the blood of the Kalpakkam population were arrived at by carrying out the analysis of plasma and red cells of healthy subjects of the Kalpakkam population. Although the "reference values" for many elements were found to be normal and comparable to values available in the literature, slight deficiency with respect to Se was noticed. Subjects with high coronary risk index were also included in the study to assess the possible correlation of elemental and lipid profile. A study of box plots showed that the elements Se, Mg, Na, K, and Fe show significant differences between "high risk" coronary risk index (CRI > 5) and "no risk" (CRI < 4.5). In the plasma, the levels of Mg, Na, and K were found to be less in the high-risk group. In red cells, the amount of Se, Fe, and K were found to be significantly less in the "high-risk" group as compared to the "no-risk" group.