Impacts of the liquid environment on the characteristics of pulsed laser ablation (PLA) synthesized tungsten (W) nanostructures have been investigated. High purity W target was irradiated by the fundamental wavelength of a Q-switched Nd:YAG laser of 7 ns pulse width and 1 J/cm2 laser fluence in different liquid environments including distilled water, ethanol, acetone, and cetrimonium bromide (CTAB) solutions. Structural, chemical, and optical properties of W nanoparticles (NPs) were characterized by different spectroscopic and imaging techniques. FTIR spectra indicate the formation of a bond between W and O in the synthesized NPs, and XRD patterns confirm producing W and WO3 composite NPs in all liquid environments. The excitonic/plasmonic absorption peak of W/WO3 NPs were occurred in the absorption spectra of all samples. The largest particles with the lowest adhesion were synthesized in acetone solution, and adding CTAB surfactant to distilled water reduced the adhesion of NPs as is depicted by FESEM. TEM images confirm the formation of core-shell W/WO3 nanostructures in distilled water. The PL spectra present band-to-band transitions and oxygen vacancies of WO3. Manuscript profile

Thermal plasma treatment is considered as a suitable alternative for the treatment of highly-hazardous wastes such as industrial, radioactive and medical waste. Therefore, a Plasma-Gasification-Melting (PGM) system for treatment of Chemical and Pharmaceutical Wastes (CPW) with a capacity of 1 ton/day is developed using a melting and gasification furnace equipped with two non-transferred thermal plasma torches. In this article, the whole method of chemical and pharmaceutical waste disposal is presented along with exhaust gas analysis, and slag and energy balance approach for improving the relevant technology process. It is successfully demonstrated that the thermal plasma process converts chemical and pharmaceutical wastes into harmless slag. Also, the associated emission level of air pollutants is shown to be very low. The synthetic gas produced can be used as a source of energy. (11.7 Nm3 / hr for CO and 16.4 Nm3 / hr for H2). The total power consumption of the system is 120 k W including 90 kW for thermal plasma torch and 30 kW for utilities with natural gas flow rate of 1.3 Nm3/hr. Manuscript profile

In the present paper, the micron-size silver and titanium powder with desired weight ratios is used to produce the silver-titanium nanocomposite using the self-developed thermal plasma equipment. The mixture is fed into the plasma torch flame by the powder feed system and argon carrier gas. After evaporation, the particles are cooled inside the cooling chamber and collected from the surface of the water-cooled double-walled chamber. The production of Titanium-Silver bimetallic nanoparticles is achieved in two ways: the cooling chamber is once filled with argon and once with atmospheric air. The nanoparticles are analyzed using scanning electron microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction (XRD) methods to identify the nanoparticle size distribution, morphology and chemical composition properties. The morphology of the produced nanocomposites is spherical and their average size is 30 nm. The results indicate that the average size of nanoparticles produced in the presence of air is smaller than those in the presence of argon Manuscript profile

AbstractIn this study, Al2O3/Pd(NO3)2/zeolite composite films have been fabricated by roll coating method and characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy and field emission scanning electron microscopy. The gas adsorption was tested in an experimental setup by a continuous gas analyzer KIMO KIGAZ 210 at constant temperature and pressure (32 °C and 1.5 bar) and as a function of reaction time (s). The inlet CO gas concentration was 150 mg L−1, and the saturation level of CO gas concentration was 5 mg L−1. The maximum adsorption capacity (qmax) and maximum adsorption efficiency (%) were calculated as 111.16 mg g−1 and 97%, respectively. Pseudo-first-order, pseudo-second-order, and intra-particle diffusion models were investigated to kinetic study of CO adsorption on Al2O3/Pd(NO3)2/zeolite adsorbents. Results indicated that CO adsorption follows the pseudo-second-order model well according to regression coefficient value (R2 = 0.98), and the value of pseudo-second-order rate constant of adsorption was obtained as 2 × 10−5 g mg−1 s−1. According to the intra-particle diffusion model, adsorption is affected by only one process. So, adsorption of CO by Al2O3/Pd(NO3)2/zeolite adsorbent indicated an effective adsorption by obtained results. Manuscript profile

AbstractIn this study, the effect of oxygen content on a thin copper oxide layer deposited on BK7 and steel substrates by DC magnetron sputtering were investigated. Argon as working gas with impurity of 99.9% and various oxygen ratios were used to sputter a pure Cu cathode target in a cylindrical geometry. The produced samples were analyzed by X-ray diffraction (XRD), energy-dispersive X-ray (EDX), atomic force microscopy (AFM), and spectrophotometry techniques. The films thickness was measured by profilometer facility. The results show that by increasing oxygen content in the working gas the sputtering rate reduces. Moreover, the type of oxide phase (Cu2O or CuO) in the synthesized layer and consequently its optical properties dramatically depend on Ar/O2 ratio in the working gas. Manuscript profile