Many surface modification technologies have been proposed and carried out practically by CVD, PVD et.al. Carbonized layer has been made using EDM method. In this paper, to make the nitride layer by EDM some new trials were carried out using a titanium electrode in liquid nitrogen. Experiments were carried out on carbon steel (S45C),...
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Many surface modification technologies have been proposed and carried out practically by CVD, PVD et.al. Carbonized layer has been made using EDM method. In this paper, to make the nitride layer by EDM some new trials were carried out using a titanium electrode in liquid nitrogen. Experiments were carried out on carbon steel (S45C), pure iron and cast iron. TiN can be obtained on EDMed surface. Moreover, TiCN can be found on cast iron and steel (S45C) by XRD investigation. To confirm the fabrication mechanisms of modified layer on the steel, the following experimental factors were investigated by EDS.
Moins
Par Boonsap Witchayangkoon
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Publiée le 11 Jan. 2012
Pages: 15
Lectures: 18
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To address the gap in bridging global and smaller modelling scales, downscaling approaches have been reported as an appropriate solution. Downscaling on its own is not wholly adequate in the quest to produce local phenomena, and in this paper we use a physical downscaling method combined with data assimilation strategies, to obtain...
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To address the gap in bridging global and smaller modelling scales, downscaling approaches have been reported as an appropriate solution. Downscaling on its own is not wholly adequate in the quest to produce local phenomena, and in this paper we use a physical downscaling method combined with data assimilation strategies, to obtain physically consistent land surface condition prediction. Using data assimilation strategies, it has been demonstrated that by minimizing a cost function, a solution utilizing imperfect models and observation data including observation errors is feasible. We demonstrate that by assimilating lower frequency passive microwave brightness temperature data using a validated theoretical radiative transfer model, we can obtain very good predictions that agree well with observed conditions.
Moins
Par Boonsap Witchayangkoon
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Publiée le 24 Mai 2012
Pages: 22
Lectures: 1
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Many universities are realizing that the implementation and use of online learning tool become a competitive advantage to address the actual learning needs. The purpose of this study is to determine the factors that influence users’ perceived ease of use of Webct an online learning tool. We administrated a questionnaire to...
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Many universities are realizing that the implementation and use of online learning tool become a competitive advantage to address the actual learning needs. The purpose of this study is to determine the factors that influence users’ perceived ease of use of Webct an online learning tool. We administrated a questionnaire to undergraduate students from an university in Quebec, Canada. The results tend to corroborate that ease of comprehension and ease of navigation are the key factors which influence the perceived ease of use of WebCT. More specifically, the terms used in educational web applications must be as simple and relevant as possible. Jargon and technical terms in the wording of text used for links should be carefully avoided. This research is extending the finding of IT adoption studies by specifying what make an online tool easy to use.
Moins
Par Boonsap Witchayangkoon
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Publiée le 24 Mai 2012
Pages: 15
Lectures: 0
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The assessment of area in risk of HazMat transportation is very beneficial for the planning of the management of such area. We prioritized the affected area using HazMat-Risk Area Index (HazMatRAI) developed on the basis of Fuzzy Logic. The purpose of such development is to reduce limits of the criteria used for the assessment which we...
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The assessment of area in risk of HazMat transportation is very beneficial for the planning of the management of such area. We prioritized the affected area using HazMat-Risk Area Index (HazMatRAI) developed on the basis of Fuzzy Logic. The purpose of such development is to reduce limits of the criteria used for the assessment which we found exist when displaying data related to Hazmat represented by iceberg. In this regard, we categorized type of Membership Function according to Fuzzy set method in order to match the existing criteria, both solid and abstract ones. The conditions of Fuzzy Number and Characteristic are used respectively so that all risk levels are covered. However, the displaying of HazMat-Risk Area Index needs weighing of each criterion that is used for the assessment which significance of each level varies. We used Saaty’s Analytic Hierarchy Process (AHP) to establish weighing value obtained from such assessment. Therefore it is beneficial for the preparation of area
Moins
Par Boonsap Witchayangkoon
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Publiée le 3 Mai 2012
Pages: 16
Lectures: 0
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In this paper, the internally pressure overloading autofrettage process of a thick-walled cylinder has been numerically investigated. The corresponding axi-symmetric and plane-stress finite element model has been employed. The elasto-plastic material model with nonlinear strain-hardening and kinematic hardening (the Bauschinger effect)...
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In this paper, the internally pressure overloading autofrettage process of a thick-walled cylinder has been numerically investigated. The corresponding axi-symmetric and plane-stress finite element model has been employed. The elasto-plastic material model with nonlinear strain-hardening and kinematic hardening (the Bauschinger effect) was adopted. The residual stresses in the thick-walled cylinder induced by internal autofrettage pressure have been investigated and optimized. The optimum autofrettage pressure and the maximum reduction percentage of the von Mises stress in the autofrettaged thick-walled cylinder under the elastic-limit working pressure have been found, the differences of stress and strain distribution between adopting the Bauschinger-effect and the non-Bauschinger-effect have been compared.
Moins
Par Boonsap Witchayangkoon
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Publiée le 4 Mai 2012
Pages: 19
Lectures: 3
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Nepenthes mirabilis Druce Seeds need light for their germination. The best medium for seeds germinated was half strength MS medium supplemented with 0.1 % activated charcoal. The organic substance such as coconut water, potato, and banana were not enhanced seed germinated. Shoot tip of N. mirabilis about 1 cm. long were cultured on...
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Nepenthes mirabilis Druce Seeds need light for their germination. The best medium for seeds germinated was half strength MS medium supplemented with 0.1 % activated charcoal. The organic substance such as coconut water, potato, and banana were not enhanced seed germinated. Shoot tip of N. mirabilis about 1 cm. long were cultured on half strength MS medium supplemented with 2.0 mg/l BA gave the best result in the highest average height of plant (1.3 cm). Half strength of MS medium supplemented with 1.0, 2.0, and 3.0 mg/l BA gave the same result in the highest average number of leaf per plant, leaf width, leaf length. But number of root and root length were not significant different in each concentration of BA. After cultured shoot tip in half strength MS medium supplemented with 2.0 mg/l BA for 20 weeks. It was found that the base of some shoots tip were formed the highest percentage of callus. The average number of new shoot tip (4.2 shoots) proliferated at the base of shoot tip which
Moins
Par Boonsap Witchayangkoon
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Publiée le 4 Mai 2012
Pages: 9
Lectures: 1
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Turbulent methane-air combustion in porous burner is numerically investigated. Several computed field variables considered include temperature, stream function, and species mass fractions. The one-step reaction considered consists of 4 species. The analysis was done through a comparison with the gas-phase combustion. Porous combustion...
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Turbulent methane-air combustion in porous burner is numerically investigated. Several computed field variables considered include temperature, stream function, and species mass fractions. The one-step reaction considered consists of 4 species. The analysis was done through a comparison with the gas-phase combustion. Porous combustion is found to level down the peak temperature while giving more uniform distribution throughout the domain. The porous combustion as in a burner is proved wider flame stability limits and can hold an extended range of firing capabilities due to an energy recirculation.
Moins
Par Boonsap Witchayangkoon
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Publiée le 4 Mai 2012
Pages: 10
Lectures: 1
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Catalytic hydrodeoxygenation of palm oil in dodecane over NiMo/Al2O3 has been investigated in a 300mL Parr’s reactor. Triglycerides have been converted to hydrocarbons with various molecular sizes due to the compositions of fatty acids in palm oil. In this experiment, parameters of interest are temperature, pressure and turbine...
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Catalytic hydrodeoxygenation of palm oil in dodecane over NiMo/Al2O3 has been investigated in a 300mL Parr’s reactor. Triglycerides have been converted to hydrocarbons with various molecular sizes due to the compositions of fatty acids in palm oil. In this experiment, parameters of interest are temperature, pressure and turbine speed. Liquid samples were collected and analyzed by a gas chromatography (GC) to quantify desired hydrocarbon products (C15-C18) in the diesel range. It was found that the amount of desired products depends on the studied parameters. The conversion increases as the reaction temperature and a turbine speed increase, but the operating pressure decreases. In addition, the ratios of Cn/Cn-1 (C18/C17 and C16/C15) have been presented.
Moins
Par Boonsap Witchayangkoon
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Publiée le 4 Mai 2012
Pages: 12
Lectures: 4
Téléchargements: 0
The purpose of this paper is to understand how a capillary viscometer is able to measure the viscosity of a fluid, which equals time required to empty a given volume of liquid through an orifice. A fluid analysis was done on a capillary viscometer in order to derive equations to theoretically describe the viscometer. In addition,...
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The purpose of this paper is to understand how a capillary viscometer is able to measure the viscosity of a fluid, which equals time required to empty a given volume of liquid through an orifice. A fluid analysis was done on a capillary viscometer in order to derive equations to theoretically describe the viscometer. In addition, physical experiments were undertaken in order to correlate empirical data with theoretical models. Various fluids were tested and their corresponding times were recorded. Time readings were taken at two separate temperatures of 25oC and 100oC. The kinematic viscosity of a fluid is measured in Saybolt Universal Seconds (SUS), which is related to the kinematic viscosity of the tested fluid.
Moins
Par Boonsap Witchayangkoon
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Publiée le 20 Jan. 2012
Pages: 20
Lectures: 15
Téléchargements: 1
This work proposes a rugged and reliable set-up to characterize incoherently illuminated optical imaging systems. It complies with the ISO 12233 standard and is suitable for industrial applications. The standard has been implemented taking advantage of the allowed degrees of freedom to optimize noise robustness. Key points of the...
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This work proposes a rugged and reliable set-up to characterize incoherently illuminated optical imaging systems. It complies with the ISO 12233 standard and is suitable for industrial applications. The standard has been implemented taking advantage of the allowed degrees of freedom to optimize noise robustness. Key points of the algorithm are automatization of the whole measurement procedure and customization, to comply with specific needs. Experimental results confirming the successful implementation are presented and discussed.
Moins
Par Boonsap Witchayangkoon
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Publiée le 20 Jan. 2012
Pages: 15
Lectures: 35
Téléchargements: 6
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