An Analysis of RF Sputtering Power and Argon Gas Pressure Affecting on ITiO Films Characteristics

Titanium-doped indium oxide (ITiO) is widely  used as a contact for photovoltaics as a high-performance  transparent conducting oxide. The titanium-doped indium oxide (ITiO) films were deposited on corning glass substrates using RF magnetron sputtering method. In this research, we verified  the effect of RF sputtering power and argon gas pressure on the structural and electrical properties of the films using a 2.5 wt% TiO2 -doped In2O3 target. The deposition rate was in the range of 0 to 35 nm/min under 2.5 to 12.5 mTorr of gas pressure and 100 to 250 W of RF power. As a result of the lowest volume resistivity of 4.9×10-4 ?-cm and the average optical transmittance of 75% were obtained for the ITiO film, using 200 W RF power and 10 mTorr Ar gas pressure. This volume resistivity is low enough for being transparent conducting layer in various electro-optical devices. Keywords RF sputtering, Argon gas pressure, Transparent conducting oxide, Titanium-doped indium oxide, TiO2, In2O

The Design and Analysis of a Novel Vertical Axis Small Water Turbine Generator for Installation in Drainage Lines

The objective of this study was to determine the mechanical power efficiency of a novel vertical-axis small water turbine generator for installation in drainage lines. A 3D model was created to evaluate the performance of each design. The system was designed, analysed, and calculated for the most suitable geometries of the water inlet, drainage lines, main structure, and water turbine wheels using computational fluid dynamics software. The diameter of the water turbine wheel in the numerical model was 48 mm. The control volume technique was used in the numerical simulation method, and the k-epsilon turbulence model was employed to find the computational results. For the Computational Fluid Dynamics (CFD), the appropriate mash element for each model section was generated for numerical simulation, which showed that the torque from the water turbine modelling varied depending on the time domains and was related to speed relative to the developed force. The maximum torque and maximum power that a vertical-axis small water turbine for installation in a drainage line could generate at a maximum flow rate of 0.0030 m3/s were 0.55 N.m and 26.84 watts, respectively. Similarly, calculations with mathematical equations, found that the maximum mechanical power value after calculating the rate of loss within the pipe system was 12.95 watts. The forces generated by the speed and pressure of the fluid can then be applied to the structure of the water turbine wheel. The vertical-axis small water turbine for installation in a drainage line was analysed under its self-weight by applying a gravitational acceleration of 9.81 m/s2 in Solidworks Simulation software version 2022. The numerical simulations that resulted from this research could be used to further develop prototypes for small water turbines generating commercial electricity

Measurement of the thermal conductivity of construction materials using a thin film probe

The objective of this research work was to develop a thin film thermal conductivity probe for measuring thermal property of construction materials. This probe was developed based on the line heat sourceprinciple. The thermal conductivity can be determined from the slope of linear relation between the temperature differences ΔT and logarithm of time ln(t). The probe was tested by measuring the thermal conductivityof three kinds of specimens comprising of polystyrene foam (PS), autoclaved aerated concrete (ACC) and gypsum board (GB) The range of electrical power supply rate for the probe was varied from 0.15 to1.59 W. The thermal conductivity values obtained with this method were greater compared to the results obtained using the ASTM C 177. The difference of thermal conductivity between line two methods decreasedwith the increase of the power supply rate. The mean difference for PS, ACC and GB was 4.33%, 6.15% and 42.34% respectively. According to the restriction of minimum thickness requirement of specimen for testingwith the guard hot plate apparatus (ASTM C 177), it was necessary to overlay one GB slab on another. As a result, the mean difference of thermal conductivity for GB was considerably high