Simple low‐cost microwave plasma source

1986 ◽  
Vol 57 (2) ◽  
pp. 164-166 ◽  
Author(s):  
L. G. Meiners ◽  
D. B. Alford
2021 ◽  
Vol 11 (12) ◽  
pp. 5358
Author(s):  
Ju-Hong Cha ◽  
Sang-Woo Kim ◽  
Ho-Jun Lee

For a conventional linear microwave plasma source (LMPS) with a quasi-coaxial line transverse electromagnetic (TEM) waveguide, a linearly extended plasma is sustained by the surface wave outside the tube. Due to the characteristics of the quasi-coaxial line MPS, it is easy to generate a uniform plasma with radially omnidirectional surfaces, but it is difficult to maximize the electron density in a curved selected region. For the purpose of concentrating the plasma density in the deposition area, a novel LMPS which is suitable for curved structure deposition has been developed and compared with the conventional LMPS. As the shape of a circular waveguide, it is filled with relatively high-permittivity dielectric instead of a quasi-coaxial line waveguide. Microwave power at 2.45 GHz is transferred to the plasma through the continuous cylindrical-slotted line antenna, and the radiated electric field in the radial direction is made almost parallel to the tangential plane of the window surface. This research includes the advanced 3D numerical analysis and compares the results with the experiment. It shows that the electron density in the deposition area is higher than that of the conventional quasi-coaxial line plasma MPS.


2011 ◽  
Vol 39 (11) ◽  
pp. 2906-2907 ◽  
Author(s):  
Helena Nowakowska ◽  
Mariusz Jasinski ◽  
Jerzy Mizeraczyk

1999 ◽  
Vol 14 (4) ◽  
pp. 258-260 ◽  
Author(s):  
W. Paszkowicz

X-ray powder diffraction pattern for InN synthesized using a microwave plasma source of nitrogen is reported. The data were obtained with the help of an automated Bragg-Brentano diffractometer using Ni-filtered CuKα radiation. The lattice parameters for the wurtzite-type unit cell are ao=3.5378(1) Å, co=5.7033(1) Å. The calculated density is 6.921±0.002 g/cm3.


2018 ◽  
Vol 232 (5-6) ◽  
pp. 635-648 ◽  
Author(s):  
Mario Nachbar ◽  
Denis Duft ◽  
Alexei Kiselev ◽  
Thomas Leisner

Abstract The article reports on the composition, mixing state and water affinity of iron silicate particles which were produced in a non-thermal low-pressure microwave plasma reactor. The particles are intended to be used as meteoric smoke particle analogues. We used the organometallic precursors ferrocene (Fe(C5H5)2) and tetraethyl orthosilicate (TEOS, Si(OC2H5)4) in various mixing ratios to produce nanoparticles with radii between 1 nm and 4 nm. The nanoparticles were deposited on sample grids and their stoichiometric composition was analyzed in an electron microscope using energy dispersive X-ray spectroscopy (EDS). We show that the pure silicon oxide and iron oxide particles consist of SiO2 and Fe2O3, respectively. For Fe:(Fe+Si) ratios between 0.2 and 0.8 our reactor produces (in contrast to other particle sources) mixed iron silicates with a stoichiometric composition according to FexSi(1−x)O3 (0≤x≤1). This indicates that the particles are formed by polymerization of FeO3 and SiO3 and that rearrangement to the more stable silicates ferrosilite (FeSiO3) and fayalite (Fe2SiO4) does not occur at these conditions. To investigate the internal mixing state of the particles, the H2O surface desorption energy of the particles was measured. We found that the nanoparticles are internally mixed and that differential coating resulting in a core-shell structure does not occur.


Author(s):  
Abimbola O. Aleshinloye ◽  
Kemayou Ngangsso ◽  
Feyisara B. Adaramola ◽  
Adebayo Onigbinde

This study investigated the potential of some agricultural wastes viz; African Star apple seed shell (ASS, plant source), crab shell (CS, animal source) and chicken egg shell (ES, animal source) as eco-friendly and low-cost biological materials for the removal of heavy metals from poultry wastewater. TS, TSS and TDS of the wastewater sample were assayed by filtration methods, chloride content by previously reported method and heavy metal contents (Zn, V, Cd, Fe, Ni, Cu, Co, Pb, Cr and Mn); were analyzed using Microwave Plasma Atomic Emission Spectrometer. The results of the solids and chloride contents of the poultry wastewater were TDS (3100 mg/L), TS (3700 mg/L), TSS (6000 mg/L) and chloride (4.7 g/L); all above the EPA permissible limits. Results of the FTIR analysis showed that ASS is an amide polymer while the CS and ES shells are mixtures of amide and carbonate polymers. Also, results of heavy metal analysis before and after adsorption showed that ASS caused removal of Zn, V, Fe, Cu, Co/ Pb and Mn by 48.27, 32.22, 49.64, 91.44, 100 and 82.39% respectively while Cd, Ni and Cr contents increased by 31, 61 and 48.3% respectively. CS showed removal of Fe, Ni/ Co/ Cr, Pb and Mn by 89.64, 100, 3.51 and 95.96% respectively while Zn, V, Cd and Cu contents increased by 1.7, 61.2, 76.1 and 68.1% respectively. Meanwhile, with ES, the contents of Zn, Fe, Ni, Cu, Cr and Mn increased by 31.56, 86.36, 100, 55.5, 45.80 and 90.33% respectively while the contents of V, Cd, Co and Pb decreased by 78.9, 86.7, 42.5 and 46.2% respectively. This study demonstrated the use of ASS, CS and ES as low- cost and eco-friendly agricultural wastes with significant potential for removal of heavy metals from wastewaters.


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