scholarly journals Perancangan Teknologi Sederhana Untuk Membangkitkan Microwave Plasma Dalam Cairan

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Muhammad Firdan Nurdin

Plasma technology has interested, especially plasma in liquid which can be applied in the process of gas productions, water treatment, and nanomaterial productions. The purpose of this study is to make a simple technology 2.45 GHz microwave plasma and generate in the variation of liquids such as distilled water, seawater, and X-Ray liquid waste by utilizing a microwave oven, as well as to observe the effect of vacuum pressure variations. A microwave oven was modified by integrating a waveguide and a plasma reactor for plasma observation. The results, plasma was generated in distilled water at a vacuum pressure of about 7 kPa, X-Ray liquid waste at a vacuum pressure of about 13 kPa, and seawater at a vacuum pressure of about 34 kPa.

1993 ◽  
Vol 306 ◽  
Author(s):  
M. F. Ravet ◽  
A. Gicquel ◽  
E. Anger ◽  
Z. Z. Wang ◽  
Y. Chen ◽  
...  

AbstractDeposition parameters acting on nucleation and growth local conditions have been optimized in a bell jar microwave plasma reactor to obtain polycrystalline diamond thin films compatible with X-ray membrane requests. The microstructure and the chemical quality of the films were estimated by SEM and Raman spectroscopy respectively, the roughness was evaluated by AFM experiments and the residual stress was deduced from the substrate deflection method. Membranes were obtained by removing the silicon substrate on 15 mm diameter circular windows. The optical transparency depending on deposition conditions was optimized up to 65% at 630 nm for 1 μm thickness. A high resolution additive mask process, based on well taut membranes and low stress electroplated gold absorber, was carried out. Micrometric and submicrometric mask patterns were generated in photoresists both by electron beam lithography with a nanopattern generator and by X-ray lithography using the synchrotron radiation facility implemented at LURE-Orsay. Despite the diamond films roughness of the order of 30 nm, well defined dots and lines as narrow as 100–200 nm could be obtained.


1995 ◽  
Vol 383 ◽  
Author(s):  
D. Rats ◽  
L. Bimbault ◽  
L. Vandenbulcke ◽  
R. Herbin ◽  
K. F. Badawi

ABSTRACTA major problem for diamond coating applications is that diamond films tend to exhibit poor adherence on many. substrates and typically disbond at thicknesses of the order of few micrometers due especially to residual stresses. Residual stresses in diamond are composed of thermal expansion mismatch stresses and intrinsic stresses induced during film growth. Diamond films were deposited in a classical microwave plasma reactor from hydrocarbon-hydrogen-oxygen gas mixtures. Thermal stresses were directly calculated from Hook's law. On silicon substrate, intrinsic stresses were deduced by difference from measurements of total stresses either by the curvature method or by X-ray diffraction using the sin 2ψ method. These investigations allow us to discuss the origin of the intrinsic stresses. The residual stress level was also investigated by Raman spectroscopy as a function of the deposition conditions and substrate materials (SiO2, Si3N4, Si, SiC, WC-Co, Mo and Ti-6A1-4V). We show that the thermal stresses are often preponderant.


2014 ◽  
Vol 8 (2) ◽  
pp. 69-80 ◽  
Author(s):  
Awadesh Mallik ◽  
Nandadulal Dandapat ◽  
Shirshendu Chakraborty ◽  
Ashok Mandal ◽  
Jiten Ghosh ◽  
...  

Polycrystalline diamond (PCD) coatings ranging from few microns to several hundred microns thickness have been grown by 915MHz microwave plasma reactor with 9000W power. The coatings were deposited on 100mm diameter silicon (Si) substrate from few hours to several days of continuous runs. PCD coatings were made freestanding by wet chemical etching technique. The deposited PCDs were evaluated by X-ray diffraction (XRD), scanning electronmicroscopy (SEM), Raman spectroscopy,X-ray photoelectron spectroscopy (XPS) for physical characterization and compared with authors? earlier work. Refractive index of 2.41 was obtained at 633 nm wavelength and a maximum of 6.6 W?cm-1K-1 value for thermal conductivity could be achieved with the grown coatings. The values are well above the existing non-diamond heat spreading substrates, which makes the grown PCDs as candidates for heat spreaders in different technological applications. High refractive in- dex along with translucent nature of the white freestanding PCDs, make them potential candidate for optical windows.


Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5813
Author(s):  
Imed Ghiloufi ◽  
Miqad S. Albishi ◽  
Ahmed A. Alharbi ◽  
Ibrahim A. AlShunaifi

The phosphate industry generates a large amount of waste called phosphogypsum (PG). Generally, this waste is discharged without any treatment, and it causes considerable environmental problems. Hence, the objective of this study is the treatment of phosphate waste using thermal plasma technology. First, the waste is characterized using different techniques, such as X-ray fluorescence (XRF), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and inductively coupled plasma (ICP). Such characterization shows that the waste contains different toxic elements, such as heavy metals, fluorine, chlorine, sulfur, and phosphorus. For this reason, a plasma reactor is used to separate toxic elements from metals, such as silicon, aluminum, and magnesium, with a pyrolysis/combustion plasma system. In this work, the influence of different parameters, such as time of treatment and plasma current, on the volatility of toxic elements is studied. The obtained results show that after 40 min of treatment and at a plasma current of 160 A, the phosphogypsum completely melts, and the most toxic elements, namely Pb, Cd, V, Cr, and As, are completely vaporized.


1986 ◽  
Vol 84 ◽  
Author(s):  
Masahiro Okamoto ◽  
Koichi Chino ◽  
Tsutomu Baba ◽  
Tatsuo Izumida ◽  
Fumio Kawamura ◽  
...  

AbstractA new solidification technique using cement-glass, which is a mixture of sodium silicate, cement, additives, and initiator of the solidification reaction, was developed for sodium borate liquid waste generated from pressurized water reactor (PWR) plants. The cement-glass could solidify eight times as much sodium borate as cement could, because the solidifying reaction of the cement-glass is not hindered by borate ions.The reaction mechanism of sodium silicate and phosphoric silicate (initiator), the main components of cement-glass, was studied through X-ray diffraction and compressive strength measurements. It was found that three- dimensionally bonded silicon dioxide was produced by polymerization of the two silicates. The leaching ratio of cesium from the cement-glass package was one-tenth that of the cement one. This low value was attributed to a high cesium adsorption ability of the cement-glass and it could be theoretically predicted accordingly.


2004 ◽  
Vol 61 (7-12) ◽  
pp. 650-662 ◽  
Author(s):  
Dmitry M. Vavriv ◽  
V. I. Kazantsev ◽  
P. M. Kanilo ◽  
N. I. Rasyuk ◽  
K. Schunemann ◽  
...  

2019 ◽  
Vol 20 (2) ◽  
pp. 633-643
Author(s):  
Xiaopeng Qi ◽  
Junwei Chen ◽  
Qian Li ◽  
Hui Yang ◽  
Honghui Jiang ◽  
...  

Abstract There is an urgent need for an effective and long-lasting ceramic filter for point-of-use water treatment. In this study, silver-diatomite nanocomposite ceramic filters were developed by an easy and effective method. The ceramic filters have a three-dimensional interconnected pore structure and porosity of 50.85%. Characterizations of the silver-diatomite nanocomposite ceramic filters were performed using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Silver nanoparticles were confirmed to be formed in situ in the ceramic filter. The highest silver concentration in water was 0.24 μg/L and 2.1 μg/L in short- and long-term experiments, indicating very low silver-release properties of silver-diatomite nanocomposite ceramic filter. The nanocomposite ceramics show strong bactericidal activity. When contact time with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) of 105 colony forming units (CFU)/mL exceeded 3 h, the bactericidal rates of the four different silver content ceramics against E. coli and S. aureus were all 100%. Strong bactericidal effect against E. coli with initial concentration of 109 CFU/mL were also observed in ceramic newly obtained and ceramic immersed in water for 270 days, demonstrating its high stability. The silver-diatomite nanocomposite ceramic filters could be a promising candidate for point-of-use water treatment.


ChemInform ◽  
2010 ◽  
Vol 28 (32) ◽  
pp. no-no
Author(s):  
M. S. HAQUE ◽  
H. A. NASEEM ◽  
A. P. MALSHE ◽  
W. D. BROWN

1989 ◽  
Vol 43 (7) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yaoming Xie ◽  
Peter M. A. Sherwood

X-ray photoelectron spectroscopy has been used to monitor the surface chemical changes occurring on type II carbon fibers exposed to air, oxygen, and nitrogen plasmas. In all cases the plasmas caused changes in surface functionality, in terms of both C-O and C-N functionality. Prolonged exposure to the plasmas caused loss of surface functionality for air and oxygen plasmas, and extended treatment caused fiber damage. Plasma treatment of fibers promises to be an effective method of fiber treatment.


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