Papers by Keyword: Distilled Water

Abstract: Abstrac. In the present work, gold nanoparticle (Au NPs) was synthesis by pulsed laser ablation (PLA) by using Q-switched, (Nd: YAG) (E=80mJ) (λ=532,1064nm) and Number of pulses (500)pulse of the gold metal target in deionized water. The optical properties were studied with a UV-vis spectrophotometer which tests the absorbance spectra and comparison of the generated nanoparticles solution. atomic force microscope (AFM) results show that the grain size increase by decreasing wavelength. The optical limiter of the resulting colloidal solution was studied.

Abstract: On a film of aluminum oxide (Al₂O₃) formed by electrolytic oxidation in distilled water (DW), the growth, transformation of its nanoporous structure, and the generation of electroluminescence (EL) in ketones and related compounds containing carbonyl groups were studied. For those contributing to the brightest EL – acetylacetone and methylpyrrolidone, it was found that the processes described in these electrolytes proceed with the highest intensity. Under the same electrolytes and conditions, similar processes, but with a lower intensity, proceed for A₂O₃ formed on pure aluminum. It was found that, with the external voltage, thermodynamic and geometrical parameters of the electrolytic system being constant, the brightness characteristics of the EL of the anodic Al₂O₃ are influenced by its structural organization and the electrophysical characteristics of the electrolyte surrounding the oxide film, which is proposed to be arbitrarily called “nonelectrolysis” because electrolysis products are not revealed in it.

Abstract: This article deals with the performance of heat pipes, depending on the operating temperature and positions (operation angle). There is described the essential function of the heat pipe manufacturing process. Measurements were carried at an operating temperature of 40 °C to 90 °C. Stainless heat pipes were made of three kinds of materials AISI 304, AISI 310, AISI 316 and filled with a distilled water, up to 20% of the heat pipe inner volume. For each material was selected heat pipe with the best results. The heat pipes were measured at various angles of vertical inclination (0 ° - 90 °), at the working temperature 90 ° C. The performance was measured on the experimental device. Presented results show the progress of individual measurements and the effect of operating parameters on the performance of heat pipes.

Abstract: In this work, the effect of temperature of distilled water on the morphology of ZnO nanoporous thin films formed by anodizing was studied. ZnO nanoporous thin films were formed by anodizing of Zn plates at voltage 30 V in 500 ml distilled water of temperature ranged from 5 °C to 25°C. As anodized zinc plates were characterized by using SEM and XRD. Characterization of as anodized Zn plates using SEM showed that the morphologies of the as anodized Zn plates were significantly influenced by the temperature of distilled water. Nanoporous ZnO thin films were formed when 15 °C to 25 °C were used while ZnO thin films without nanoporous structures were formed when 5°C and 10 °C were used. XRD analysis indicated the ZnO thin films formed in distilled water of 5 °C to 25°C were of hexagonal wurtzite structures.

Abstract: In this work, ZnO nanoporous thin films were formed by anodizing of Zn plates in 500 ml distilled water of 25°C at voltage ranged from 10 V to 30 V. As anodized zinc plates were characterized by using SEM and XRD. Characterization of as anodized Zn plates using SEM showed that the morphology of the as anodized Zn plates were significantly influenced by the anodizing voltages. Nanoporous ZnO thin films were formed when 25 V and 30 V were used while ZnO thin films without nanoporous structures were formed when 10 V, 15 V and 20 V were used. XRD analysis indicated the ZnO thin films formed at 10 V to 30 V were of hexagonal wurtzite structures.

Abstract: Preparation of nanoparticles by pulsed Nd:YAG (1064 nm) laser ablation on copper target submerged in distilled water has been studied. Effects of pulse power and liquid height were investigated. Colloidal nanoparticles were characterized by UV-Vis spectroscopy, Raman dynamic light scattering and transmission electron microscopy. The concentration of nanoparticles was increased with the pulse power at a particular liquid height or volume. The size of nanoparticles related complicatedly to both parameters. The optimum conditions were the pulse power of 80 W and the liquid height of 3-4 mm. The obtained mean particle size was 20-37 nm, having the maximum UV-Vis absorption wavelength at 617-630 nm. The colloids contained mainly copper oxide nanoparticles.

Abstract: Micro-flowing technique gained popular applications in microdevices of microelectromechanical systems (MEMS), and the performance of micro-devices is greatly determined by the properties of micro-flow. This paper studied the characteristics of different viscosity fluid flowing over microchannels with different diameters and lengths under low pressure driving, and the influence of scale effects on the flowing characteristics of low viscosity fluids was also examined. The experiments studied the flow rate–pressure characteristics of distilled water flowing over microchannels with diameter of 13 μm, 20 μm, and silicon oil flowing over microchannels with diameters of 50 μm, 100 μm. The results indicate that, when the diameter of micro-channel is more than 20 μm, the flowing characteristics of distilled water and silicon oil agrees well with conventional flow theory, and when the diameter of microchannels is 13μm, the flowing characteristics are related to the length of micro-channel. When the length is relatively shorter, the flowing characteristics are almost in agreement with the conventional flow theory. When the length reaches 100 mm, the flow rate is much higher than the values predicted by theoretical calculation when the length reaches 100 mm. It is obvious that scale effect arises when the length arrives to 100 mm and the velocity slippage results in the great increase of flow rate.

Abstract: The spot welded structure operates in diverse climatic situations because of temperature, humidity and precipitation. In addition, factors of environmental pollution such as acid rain, that causes corrosion, have the tendency to increase. But spot welded structure strength is affected by dampness and environment temperature. Therefore, it is important to evaluate the effect of temperature of the spot welded part. In this study, the strength distribution of spot welded plates is evaluated for the environmental temperature of zinc coated steel plates and the test is conducted with the welded part immersed in distilled and synthetic sea water. Specimens are immersed into water for 10, 100, 500 and 1000hours to evaluate the effects of water immersion time on tensile-shear strength under the conditions of -40, 0, 20 and 50°C. Strength is evaluated by using the tensile-shear test. The conditions of spot welding are 240kgf electrode force, 10kA welding current with 0 and 5mm clearance. In this study, spot welded specimens with clearance have lower tensile-shear strength in the distilled water or synthetic sea water compared with spot welded specimens without clearance. And they have lower tensile-shear strength under -40°C and over 50°C.