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In order to investigate transport characteristics of chemically active species in soil during soil remediation by pulsed discharge plasma, gaseous ozone, as a model active species, was chosen in the present research. Ozone transport characteristics in soil were investigated by laboratory column experiments. Effects of soil organic matter, metal oxides, soil pH, soil moisture, and ozone initial concentration...
In this letter, a triple electrode discharge configuration is presented for producing large-diameter plasma jet near atmospheric pressure. Different from various cold atmospheric pressure plasma jets via concentric dielectric barrier discharge (DBD) configurations, the novel kind of large-diameter plasma jet generates with much larger dimension in diameter in pure argon or Ar/N 2 mixture near...
The method, proposed previously by other authors, is applied here to calculate a mass flow rate of rarefied gas through a long rectangular channel of variable cross-section aspect ratio. The gas flow through this channel is generated by the pressure and/or temperature gradient. The method is based on the results obtained previously on the basis of the kinetic equation and it requires very modest computational...
The expected emission spectra of xenon plasma have been studied for different conditions using FLYCHK code. Expected xenon plasma spectra at certain electron temperature range have been plotted. The suitable electron temperature ranges for xenon plasma soft X-ray emission and extreme ultraviolet emission have been investigated. The X-ray ratio curves for various electron temperatures with probable...
This study aimed at determining gamma-rays sensing properties of some thick oxide films (LiCoO 2 , TiO 2 , Cr 2 O 3 , Nb 2 O 5, NiO, ZnO, Zn 2 SnO 4 , SnO 2 , CeO 2 , SmFeO 3 , SmCoO 3 , WO 3 , In 2 O 3 ) in energy range of 0.015–15 MeV by calculating total mass attenuation coefficients...
High density plasma etching of MgO thin films patterned with Ti (or TiN) hard masks was conducted using Cl 2 /Ar, CH 3 OH/Ar and CH 4 /Ar gases. As the concentration of each gas increased, the etch rate of MgO thin films decreased and there was no enhancement of etch profiles except for those obtained using CH 4 /Ar gas. The etch profiles of MgO thin films under CH...
In this study, gray cast iron (GCI) and nodular cast iron (NCI) were surface melted by plasma beam to remove the negative effect of the near-surface graphite phases. Afterward, the modified surfaces were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicated that the molten surface had no pores and cracks, composing of inter-dendrites and eutectics with a...
This work investigates the sheath dynamics and implantation profiles during the plasma immersion ion implantation (PIII) process on a long step shaped target in the presence of a DC magnetic field with the different inclination angles. The fluid model is used to demonstrate the time evolution of the sheath parameters and the influence of the magnetic field on these parameters. The results of the numerical...
First-principle approach for nickel chromium binary alloy with nitrogen was proposed to determine the trapping position of nitrogen in austenitic alloys. The energy of the alloy matrix with the nitrogen atoms at different positions relative to chromium atoms were calculated by density function theory. The calculated results show that the nitrogen atom diffusion along pathways through tetrahedron site...
Using current–voltage (I–V) and capacitance–voltage (C–V) measurements, the effect of oxygen plasma treatment on the electrical properties of Ag Schottky contacts to hydrothermally-grown O-polar bulk ZnO was investigated. Schottky contacts to untreated ZnO had higher barrier heights and lower ideality factors than those to oxygen plasma treated ZnO. The measured C–V and conductance–voltage (G/ω–V)...
Dense ceramics of BaTi 1−x Zr x O 3 with x = 0.05 have been prepared by microwave sintering, and the powders were synthetized by conventional hydrothermal method. Microwave sintering was conducted at 1260–1300 °C for different soaking times (0.5 h, 1 h, 1.5 h and 2 h) in air and the hydrothermal processing was conducted at 180 °C for 10 h. The effects of soaking time on the...
The expectation of users of small quadrupole mass spectrometers (QMS) is that the partial pressures reported can be related to actual partial pressures present. To achieve this, a calibration of the QMS is needed followed by verification over time by analyzing a test mixture appropriate to the process. Four in situ calibration methods are presented: 1. For UHV base pressure and low pressure processes,...
The RF magnetron sputtered indium tin oxide (ITO) films were deposited on glass substrates with low resistivity, high transmittance and work function for various oxygen (O 2 ) flow rates. The addition of small O 2 contents during the sputtering process increased the Hall mobility of ITO films while carrier concentration was decreased. The work function of ITO films was enhanced from...
The paper is devoted to the study of a rarefied gas flow through a finite length conical pipe into vacuum. The problem is solved in the complete geometrical setup, which included not only the pipe, but also high- and low-pressure reservoirs. The analysis is based on the direct numerical solution of the Boltzmann kinetic equation with the S-model collision integral in three space dimensions. The method...
The fundamental principles of quadrupole mass spectrometers (QMS) are discussed, concentrating on instruments used in vacuum applications.The mass-selective element is the quadrupole mass filter, first described in a 1956 patent. Although originally intended for isotope separation, the concept soon became applied to analytical chemistry and to residual gas analysis (RGA), also known as partial pressure...
This paper investigates the surface and electrical characteristics of cobalt, iron, and cobalt–iron nanoparticles, based on the variation of film thickness and plasma treatment time. These ferromagnetic nanoparticles were formed by dewetting the thin films in the presence of hydrogen plasma. The results indicated that particle size increases with increasing film thickness and plasma treatment time...
The technique of X-ray photoelectron spectroscopy has been used to investigate the chemical reactivity at the Fe/CuO interfaces. The 2p core level regions of the metals have been studied. Thin films of iron (thicknesses ranging from 0.3 nm to 2.0 nm) were deposited on copper oxide substrates at room temperature. Earlier investigation on a 0.5 nm overlayer of iron on CuO showed considerable reactivity...
Low-energy ball milling of aluminum and nickel particles with an overall composition corresponding to the NiAl intermetallic phase was performed up to milling durations of 13 h. The milled powders and cold-compacted pellets were ignited using a low-energy spark. Interrupted thermal analysis and X-ray diffraction was performed to investigate the effect of milling time on intermetallic phase formation...
Density functional theory calculations have been carried out using hybrid B3PW91-functional for investigating hydrogen storage over Ti, Cr, and Fe doped borazine. The natural bond order and partial density of states analysis executed over ground (triplet) and excited (quintet) spin state of Ti–B 3 N 3 H 6 revealed that the extent of hybridization between 4s and 3d-orbitals...
A facile method was designed and developed to fabricate 3D carbon material, from inducing the growth of 1D carbon nanotubes (CNT) on to the reduced 2D graphene oxide sheets (rGO). In this method, nickel nanoparticles were firstly loaded onto graphene oxide sheets that were modified by surfactant sodium dodecyl sulfate (SDS). Then CNTs were induced to grow on nickel-loaded graphene oxide sheets via...
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