Papers by Keyword: Water

Abstract: In order to better understand and model the whole sorption behavior of the HF when in contact with a Cu surface inside a FOUP and thus control the related yield losses, Cu-coated wafers have been exposed to varying HF (ppbv) and H₂O (% RH) airborne concentrations. These experiments have yielded a HF-Cu sorption empirical-mathematical model that may be used as an industrial tool for queue-time or fluoride surface concentration predictions. Besides, the formation of CuF₂ only in case of corrosion is evidenced by the XPS measurements whereas the key role of the H₂O is further confirmed by the desorption experiments. The H₂O retained by the surface is actually responsible for promoting the HF adsorption/desorption onto/from Cu and enables a HF threshold concentration that separates the two well differenced uptake regimes; adsorption and corrosion.

Abstract: Underwater laser machining process has a high potential over the typical laser ablation to remove materials with less thermal damage occurring along the cut. However, the formations of vapor bubble and cut debris in water can substantially disturb the incident laser beam, thereby reducing the ablation performance. Instead of performing the ablation in still water, the flowing water technique was applied to flush away the cut debris and bubble generated. In this study, the effects of laser pulse energy, traverse speed and water flow rate on the cut surface roughness and heat-affected zone in the laser grooving of silicon were experimentally investigated and analyzed. The findings revealed that the cut surface roughness decreased with the increases in laser pulse energy and laser traverse speed. Though a higher water flow rate resulted in a rougher cut surface, the heat-affected zone can be minimized when the increased flow rate was applied.

Abstract: We report novel soft chemical synthesis method, solid hydratethermal reaction (SHR) method as a new soft chemistry. This method is very simple and can synthesize the ceramic materials just by storing the mixture of raw materials added a small amount of water in a reactor at low temperature below 373 K. For example, nanosize YVO₄ (under 100 nm in diameter) was obtained using the SHR method.

Abstract: In nature, there is a large number of materials to be discovered, all with different characteristics and for certain functions. In the case of plants, they are responsible for collecting, taking care and protect water naturally.In Mexico there are different plants of the cactus family, which catch and retain water for their existence, so some plants collect more volume of body water than they have. It is very important for this investigation.In Mexico and throughout the continent there is a common cactus or chumbera that easily adapts to the environment and very rampant in this country, so that its study and analysis makes it one of the most important natural systems for this research, because 95% of it is water and the other 5% is organic material.Later, the common Maguey or agave plant is analyzed, which is important for the history of ancient Mexico, this long before the Spaniards arrived in America. The agave juice and whole plant were an important part of Mexican culture [1], even today is used in many regions and is an important part of the economy in this country.Last but not least is the barrel cactus plant, which surprisingly lets us see how natural systems build structural and formal elements in order to the creation and configuration of new materials that can significantly help to collect water.

Abstract: As the hydrogen-rich gas produced by autothermal reforming from ethanol is utilized for the power generation via fuel cell, the change in amount of ethanol and water fed into the autothermal reformer has significant effects on the control of electricity generation and autothermal reaction temperature. The change of water and ethanol amounts affecting on the autothermal reformer temperature control system was studied in this work. An internal model control (IMC) method was designed to control the adiabatic reaction temperature of autothermal reformer by manipulating the input air flow rate. Theoretical analysis demonstrated that IMC method can realize desired performance to control the autothermal reaction temperature when the feed amounts were changed. The results of autothemal reformer control system with and without the feed temperature controller of the preheater unit were compared to offer the suitable control system.

Abstract: This paper is an endeavor to investigate an insulated mild steel pipe that exposed to three sea water drops rate (10, 30, and 50 drops/minute) at room temperature. Various experimental strategies were employed including visual inspection; scanning electron microscopy (SEM) with EDAX. After removing the insulation material, it was observed that pipes were corroded. However, the extent of corrosion was varied which was attributed to the drop rates, it was revealed that corrosion process was initiated due to water and ions penetration through the insulation, such revelation highlighted the necessity to properly examine the pipe and the insulating material. Results also revealed that severity of corrosion is proportional to the drops rates. EDAX analysis of the pipe surface and the insulating material shows the presence of difference ions including Na⁺, Cl^-, Mg²⁺, Si²⁺ and others, the results highlighted the importance of material selection and the necessity for early detection strategy in order to avoid catastrophic failure.

Abstract: We describe the mass-spectrometric approach to the analysis of the water release in the course of wear experiments in vacuum conditions. The approach is tested in wear experiments with polyurethanes and their composites.

Abstract: This paper presents a numerical investigation of water supply for cooling tertiary containment wall. These type of tanks are used as a part of petroleum high storage tank. Minimum quantity reasonably needed is perform by heat – balance equation. The calculation in is done for the most heat stressed wall part for a case when neighbouring tank is on fire.

Abstract: The consumption of microbially - and virally - contaminated water is a pressing health issue in developing nations. The concentration of surface and underground water is often responsible for a high incidence of diarrheal diseases, especially among children under the age of five years [1]. Ceramic water filters (CWFs) have been proposed as a household water treatment solution. However, despite their high bacterial filtration efficiency [2], existing CWFs cannot yet effectively remove viruses from water. Using MS2 bacteriophage as a model for human enteric viruses, this work explores the effect of doping CWFs with goethite (FeOOH) on the removal of viruses from contaminated waters. Fe-CWFs were found to remove bacteriophage from challenged water at significantly higher efficiencies than the control CWF. Filters composed of 60:40 ceramic:sawdust volume ratios and doped with different amounts of FeOOH were studied. A Fe-CWF containing 24.9 wt% Fe₂O₃ removed a mean of 1.93 log (98.83%) of MS2. The efficiency of viral filtration decreased significantly when the pH of the challenged water deviated from neutral (pH 5.9, 8.7 and 10.2). In addition, all Fe-CWFs tested removed more than 3 log (99.9%) of bacteria.

Abstract: Analysis of organic acids in natural water samples using by the distillation followed by the SPE procedure at Strata-X and GC-MS of trimethylsilane derivatives. Influence of distillation and elution, as well as a cartridge housing material, on the compounds recovery was discussed. Data on organic acids in some natural samples are provided.