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11.
Summary Single crystals of copper indium disulfide (CuInS2) have been grown by chemical-vapour transport technique (CVT) using iodine as the transporting agent. The obtained phase
was checked by X-ray diffractometry and the presence of copper, indium and sulfur in the grown crystals was confirmed by Energy-Dispersive
Spectrum Analysis (EDSA). The mechanical properties of the grown crystals were studied using microindentation analysis. Optical-transmission
measurements were done to determine the energy gap of the grown crystals. The four-probe technique was used to measure the
electrical properties of the grown crystals. The as-grown crystals were found to bep-type conducting and they were converted ton-type by suitable annealing treatment. The electrical parameters of bothn- andp-type crystals were measured. 相似文献
12.
Dr. Saeedeh Sarabadani Tafreshi Mahkameh Ranjbar Dr. Narges Taghizade Dr. S. F. K. S. Panahi Dr. Maryam Jamaati Prof. Nora H. de Leeuw 《Chemphyschem》2022,23(6):e202100781
As promising materials for the reduction of greenhouse gases, transition-metal carbides, which are highly active in the hydrogenation of CO2, are mainly considered. In this regard, the reaction mechanism of CO2 hydrogenation to useful products on the Nb-terminated NbC (111) surface is investigated by applying density functional theory calculations. The computational results display that the formation of CH4, CH3OH, and CO are more favored than other compounds, where CH4 is the dominant product. In addition, the findings from reaction energies reveal that the preferred mechanism for CO2 hydrogenation is thorough HCOOH*, where the largest exothermic reaction energy releases during the HCOOH* dissociation reaction (2.004 eV). The preferred mechanism of CO2 hydrogenation towards CH4 production is CO2*→t,c-COOH*→HCOOH*→HCO*→CH2O*→CH2OH*→CH2*→CH3*→CH4*, where CO2*→t,c-COOH*→HCOOH*→HCO*→CH2O*→CH2OH*→CH3OH* and CO2*→t,c-COOH*→CO* are also found as the favored mechanisms for CH3OH and CO productions thermodynamically, respectively. During the mentioned mechanisms, the hydrogenation of CH2O* to CH2OH* has the largest endothermic reaction energy of 1.344 eV. 相似文献
13.
We study the possibility of obtaining an intense fluctuating force during the steady-state operation of a waterjet. In this paper, characteristics of waterjets in the so-called first wind-induced breakup regime are briefly explained and the impaction between such waterjets and a smooth flat plate is discussed. We consider these waterjets to consist of three different regions: (1) a continuous portion, (2) a discrete portion (a stream of drops) and (3) a spray region. Using fluid dynamics simulation we obtain an impulsive impact force for the discrete portion of these waterjets. The peak of this impulsive impact force is found to be 3.5–4 times greater than that of the continuous portion. We validate our simulations by conducting an experiment for a stream of large low-speed drops. The impact force of these drops is in good agreement with that of simulation. 相似文献
14.
Chamani Alieh Abtahi Seyed Mohammad Mahdi Tafreshi Mohammad Amirhamzeh 《Journal of Radioanalytical and Nuclear Chemistry》2021,330(3):737-745
Journal of Radioanalytical and Nuclear Chemistry - The effects of high-energy protons produced in the plasma focus device on molybdenum and copper metals were studied. Molybdenum and copper samples... 相似文献
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In this note, the evaporation rate from a vertical wet fabric sheet is calculated using a free convection heat transfer correlation. Chilton–Colburn analogy is used to derive a mass transfer correlation from a heat transfer correlation proposed by Churchill and Chu for free convection from a vertical isothermal plate. The mass transfer rate obtained from this expression has shown excellent agreement with experimental data. 相似文献
17.
A. Ashari T.M. Bucher H. Vahedi Tafreshi 《International Journal of Heat and Fluid Flow》2011,32(5):1076-1081
Modeling the rate of fluid release from moving partially saturated nonwoven sheets in contact with a solid surface is a challenge, as the release rate depends on many parameters, some of which are difficult to quantify. In this paper, we report on a diffusion-controlled boundary treatment which we have developed to simulate fluid release from partially saturated porous materials onto surfaces with different hydrophilicy. The new boundary treatment considers the solid impermeable surface as a fictitious porous layer with a known fluid diffusive coefficient. Motion of the porous sheet on the surface is incorporated in the simulations by periodically resetting the saturation of the fictitious layer equal to zero, with a period obtained from the sheet’s speed of motion. Fluid transport inside the fibrous sheets is calculated by solving Richards’ equation of two-phase flows in porous media. Our numerical simulations are accompanied with experimental data obtained using a custom-made test rig for the release of liquid from partially saturated media at different speeds. It is demonstrated that the novel mathematical formulations presented here can correctly predict the rate of fluid release from moving fibrous sheets onto solid surfaces with different hydrophilicity as a function of time. 相似文献
18.
Viscosities of noble gases have been calculated over a wide temperature‐pressure range. Simple and accurate Tang‐Toennies potential of the noble gases are used in the Chapman‐Enskog calculation of the zero density viscosity and in the Rainwater‐Friend theory to determine the initial density dependence of the viscosity. At densities beyond the range of the theory (up to 46 mol.dm?3), a variant of the residual viscosity is developed. A correlation function for the calculation of viscosity over the whole range of density is presented. A comparison of the calculated and experimental values of the viscosity yields an average absolute deviation of 1.5%. 相似文献
19.
KTP crystals have been grown by two nucleation techniques namely spontaneous nucleation in flux medium and nucleation on Pt rod using K6P4O13 flux.10 °C/h, 7 °C/h, 0.8 °C/h, 0.4 °C/h and 0.2 °C/h cooling rates were applied for spontaneous nucleation and crystals up to 15 × 7 × 4 mm3 in size were grown. 1 °C/h and 0.8 °C/h cooling rates were also used for nucleation on Pt rod and crystals up to 8 × 6 × 3 mm3 in size were grown. The effect of cooling rate on size, morphology and optical quality of grown crystals by both techniques were studied. For nucleation on Pt rod upper and lower rotation rates limits and an optimum rotation rate were distinguished for each cooling rate. Quality of the grown crystals by both techniques was characterized by optical transmission analysis. 相似文献