Synthesis, characterization, and gas sensing properties of In-doped ZnO nanopowders

Indium (1at %) doped ZnO and ZnO nanoparticles have been synthesized via sol gel method. The structural characters of the synthesized nanoparticles have been studied by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM) and energy-dispersiveX-ray spectroscopy (EDX). From synthesized nanopowders a tablet was prepared by using the isostatic pressing and then sintered at 600°C. Then, the gas-sensing properties of ZnO and IZO powder tablets were evaluated with respect to the acetone gas at different temperatures and concentrations. XRD pattern and SEM images showed the prepared samples were crystallized in the wurtzite structure with the average particle size of 32 and 27 nm. The gas sensing measurement results showed that the indium dopant ions improved the gas sensitivity of ZnO for high acetone concentrations effectively. Therefore, it is suggested that the IZO tablet can act as reliable and low cast gas sensor for acetone detection. Sintering temperature strongly increased the grain size and density of samples. EDX analysis confirmed the presence of indium in zinc oxide structure

The Effect of Annealing Temperature on the Structure and Hardness of Palladium Thin Film

Palladium thin films, with a thickness of about 110 ?, were deposited at room temperature on glass substrates, by electron beam evaporation method, and subsequently annealed at 523, 598, 673, 748, 773, 798 and 823 K for an hour, and then were cool down slowly. The structure and hardness of the thin films were investigated using X-Ray Diffraction (XRD) and Vickers Micro Hardness (MHV) analysis respectively. XRD patterns showed that the structure is amorphous before annealing and as the annealing temperature increases, the structure of Pd thin films become crystallized gradually. The Vickers Micro Hardness modifications of the Pd thin film showed that the heat treatment resulted in the structural compression of the sample and therefore the density increased compared to the preheating temperature. Thus, by heating up to the re-crystallization temperature, the Pd thin film-tensile strength increased, which is itself due to the mechanical behaviour of the material, and has a significant effect on its efficiency. So we realized that the hardness of the thin films is directly affected by annealing temperature

Infrared Spectroscopy Studies on sol-gel prepared alumina Powders

Gamma-alumina fine particles were synthesized by sol-gel process. Aluminum tri-sec-butoxide (ATB), anhydrous ethyl alcohol (EtOH), water (H2O) and hydrochloric acid (HCl) were used as starting materials. Different samples were synthesized with EtOH/ATB=60/1, HCl/ATB=0.08/1 and H2O/ATB=1/1 ratios and calcined at different temperatures. Molar ratios of H2O/ATB (from 1 to 25) and HCl/ATB (from 0.08 to 0.4) were changed for some other samples, during synthesizing process. The products were characterized by both XRD and FTIR measurements. Studies were carried out on the effect of calcination temperature and change of H2O/ATB and HCl/ATB ratios on structure and processes involved in phase transformations.DOI: http://dx.doi.org/10.5755/j01.ms.21.1.4872</p

Studies on Properties of Ag\Al 2 O 3 Nanocomposite Synthesized by Solution Combustion Technique Under Novel Condition

Abstract Ag\Al 2 O 3 nanocomposite were synthesized by solution combustion Technique using ammonium carbonate as a new fuel under simultaneous combustion of alumina and silver particles condition. Samples prepared with different amount of silver, were characterized by XRD, BET, SEM and optical Absorption measurements. XRD analysis was used to determine the change in phase and size of the synthesized nanoparticle with adding silver. BET analysis showed that added silver reduced specific surface but which is still suitable for catalytic application. BJH analysis showed that pores in Ag/Al 2 O 3 nano composite are mesoporous and in Al2O3 nano particles is microporous. TEM and SEM showed that silver was distributed completely homogenously in pores of Alumina, and didn&apos;t change in surface of Alumina. Optical transmission showed the different existence of different Ag species. JNS All rights reserved Article history

Effect of charge on the structural properties of hydrogen doped ZnO

Effect of charge on the structural properties of Wurtzite ZnO doped with interstitial hydrogen was investigated using Density Function Theory. Calculation performed using Quantum Espresso package with Generalized Gradient Approximation (GGA). Calculations for formation energy showed that H+ is more stable than H0 and H- doping in this structure. Charge density calculation and Bader analysis showed that for all three H+, H0 and H- states hydrogen due to its higher electronegativity in compared with Zn atoms, joins to oxygen and increases its charge and repulses zinc atom. Hydrogen doping affects on volume of supercells due to locating in space charge density, therefore cell parameters and volume of supercell decrease in H+ state, while these values increase for H0 and H- states

Fuel effects on properties of alumina nanoparticles synthesized by combustion technique

Alumina nanopowders have been produced by solution combustion synthesis using aluminum nitrate as oxidizer and urea (U), ammonium acetate (AA) and ammonium nitrate (AN) as fuels. The fuel effects on properties of products have been studied. Enthalpy and adiabatic flame temperature are calculated theoretically for each fuel based on thermodynamic concept to determine its exothermicity. Thermogravimetric (TG) analysis has also been carried out to determine the thermal properties of the metal nitrate and fuels. The prepared samples have been characterized by X-ray diffraction (XRD), N2 adsorption (BET) and scanning electron microscopy (SEM). The results show that by reducing the exothermicity of reaction, alumina nanopowders with smaller crystallite size, finer agglomerate and higher specific surface area are produced

<span style="font-size:10.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-US">Effect of crucible shape on the solution hydrodynamic in the growth of KTiOPO₄single crystals by top-seeded solution growth method: A numerical analysis</span>

675-680Three-dimensional solution flow and temperature field simulations were performed to model the growth of KTiOPO4 single crystals by TSSG method. Steady flow and temperature field for four crucible shapes were computed using finite volume method. Our results show the effect of crucible shape on axial flow which has direct effect on homogeneity of solution, morphology of crystal and mass transport during the growth of crystals from solution. In order to consider the simulation results, KTiOPO4 single crystals were grown by TSSG method in crucibles with different shapes. </span

How Does Service Quality Lead to Loyalty in the Hotel Industry in Iran

Abstract: This is a fact that loyal customers not only use the services of the hotel frequently but also suggest the services to other potential clients. It is obvious that loyal customers can guarantee the life of the business in the hotel industry. The theoretical background of the loyalty in the hotel industry indicates that loyalty is a consequence of hotel service quality. The main purpose of this study is to investigate how the service quality ends in loyalty in hotel industry in Iran. Review on the literature revealed that there are some factors between service quality and loyalty. In other words, high service quality can enhance the perceived value and customer satisfaction. Furthermore, this is the satisfaction that increases the loyalty of the clients. This study considers five dimensions of SERVQUAL instrument as factors of service quality in hotel industry which have been applied in similar research successfully. The hypotheses are tested with a convenience data collection approach using data from clients of four Iranian hotels. Findings indicated that some service quality dimensions significantly affect the perceived value. Furthermore, dimensions of service quality and also the perceived value directly influence satisfaction. Finally, satisfaction significantly enhances the loyalty