Search results for "PLASMA"
showing 10 items of 4043 documents
An X-ray characterization of the central region of the supernova remnant G332.5-5.6
2015
Aims. We present an X-ray analysis of the central region of supernova remnant (SNR) G332.5-5.6 through an exhaustive analysis of XMM-Netwon observations with complementary infrared observations. We characterize and discuss the origin of the observed X-ray morphology, which presents a peculiar plane edge over the west side of the central region. Methods. The morphology and spectral properties of the X-ray SNR were studied using a single full frame XMM-Netwon observation in the 0.3 to 10.0 keV energy band. Archival infrared WISE observations at 8, 12 and 24 μm were also used to investigate the properties of the source and its surroundings at different wavelengths. Results. The results show th…
Anomalous and normal Hall effect in hydrogenated amorphous Si prepared by plasma enhanced chemical vapor deposition
2010
The double sign anomaly of the Hall coefficient has been studied in p -doped and n -doped hydrogenated amorphous silicon grown by plasma enhanced chemical vapor deposition and annealed up to 500 °C. Dark conductivity as a function of temperature has been measured, pointing out a conduction mechanism mostly through the extended states. Anomalous Hall effect has been observed only in the as-deposited n -doped film, disappearing after annealing at 500 °C, while p -doped samples exhibit normal Hall effect. When Hall anomaly is present, a larger optical band gap and a greater Raman peak associated with Si-H bond are measured in comparison with the cases of normal Hall effect. The Hall anomaly wi…
Concentration of chromium and nickel in serum of patients with orthopedic implant: An analysis
2021
Introduction: Surgical corrections of fracture using fixation devices made from various alloys (stainless steel, cobalt-chromium alloys, and titanium) carry a risk of these alloys leaching into circulation, potentially causing undesired health effects. Hence, monitoring the levels of metal ions in the serum of postoperative patients with metal implants is mandated. Materials and Methods: Blood samples from seventy patients with orthopedic metal implants was collected after a minimum postoperative period of 1 year. The samples were subjected to triple acid digestion and serum levels of chromium and nickel were analyzed using inductively coupled plasma-mass spectrometry. Results: The concentr…
Determination of selenium, zinc and cadmium in antidandruff shampoos by atomic spectrometry after microwave assisted sample digestion
2000
Microwave assisted pre-treatments for atomic spectrometric determination (inductive coupled plasma-optical emission spectrometry, ICP-OES or flame atomic absorption spectrometry, FAAS) of metallic elements, usually present in antidandruff shampoos, are proposed. They are based on the digestion of the sample with HNO(3) into a closed reactor, which is irradiated at 800 W for a few minutes. Selenium was determined by ICP-OES. The limit of detection was 0.11 mg l(-1); the relative standard deviation (R.S.D.) for the selenium content in the samples was in the 0.6-3.6% range. The results obtained were in agreement with the label contents and the recovery of the proposed method was in the 100-106…
Production of Phosphorescent Coatings on 6082 Aluminum Using Sr0.95Eu0.02Dy0.03Al2O4-δ Powder and Plasma Electrolytic Oxidation
2019
In this study, a new approach for producing phosphorescent aluminum coatings was studied. Using the plasma electrolytic oxidation (PEO) process, a porous oxide coating was produced on the Al6082 aluminum alloy substrate. Afterwards, activated strontium aluminate (SrAl2O4: Eu2+, Dy3+) powder was filled into the cavities and pores of the PEO coating, which resulted in a surface that exhibits long-lasting luminescence. The structural and optical properties were studied using XRD, SEM, and photoluminescence measurements. It was found that the treatment time affects the morphology of the coating, which influences the amount of strontium aluminate powder that can be incorporated into the coating …
Low-Intensity Neutron Emission from TiDx Samples Under Nonequilibrium Conditions
2001
Several experiments were performed that loaded titanium samples with deuterium from the gas phase, changed the temperature of the samples over a wide range, and monitored the neutron emission. Neutron emissions in very low intensity bursts, still significantly above the background, were recorded, revealing that low-energy nuclear reactions in condensed matter can be produced at a very low rate, which occasionally can be high enough to become detectable.
Determination of copper, iron, molybdenum and silicon in hydrometallurgically roasted molybdenite concentrate solution by inductively coupled plasma …
1997
Abstract Inductively coupled plasma atomic emission spectrometry has been applied for the estimation of major constituents in molybdenite concentrate solutions produced by hydrometallurgical alkaline digestion. Copper, iron, molybdenum and silicon were considered as major constituents to be determined. Multiple linear regression was utilized for the control of matrix effects. Using simple acid-based standards, all the elements investigated could be determined with satisfactory results using an appropriate method of calculation.
The measurement of impurities in silicon for solar cell production
2012
The power conversion efficiency of solar cells is largely dependent on impurity levels in silicon. In the current investigations two sample preparation methods of silicon had been used before analysis - acid dissolution at atmospheric pressure and pressured microwave assisted technique. Quantification of impurities in solar silicon was done by inductively coupled plasma mass spectrometry and electrothermal atomic spectrometry. Microwave assisted dissolution of solar silicon was more effective compared to the traditional dissolution method on the hot plate, but complete dissolution of impurities and silicon matrix was achieved with a nitric and hydrofluoric acid mixture. The mass of solar si…
Novel method for determination of tritium depth profiles in metallic samples
2019
Tritium accumulation in fusion reactor materials is considered a serious radiological issue, therefore a lot of effort has been concentrated on the development of radiometric techniques. A novel method, based on gradual dissolution, for the determination of the total tritium content and its depth profiles in metallic samples is demonstrated. This method allows for the measurement of tritium in metallic samples after their exposure to a hydrogen and tritium mixture, tritium containing plasma or after irradiation with neutrons resulting in tritium formation. In this method, successive layers of metal are removed using an appropriate etching agent in the controlled regime and the amount of evo…
A discourse on human hair fibers and reflections on the conservation of drug molecules
1996
A gross discourse on human hair fibers and their formation is presented stressing the various interdisciplinary aspects, such as the morphological, biological, structural and biochemical data considered to be important in the field of hair analysis. An attempt is made to explain the incorporation of drug molecules during hair fiber formation by using the classical concepts of drug absorption based on lipoid theory and the pH-partition hypothesis as well as a modern biological approach on the permeability of cell membranes. In addition to the physiochemical considerations of the transport properties of a particular drug molecule such as a) the lipophilicity, which determines permeability thr…