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.
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From Boonsap Witchayangkoon
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Pub. on Jan. 11th 2012
Pages: 15
Views: 18
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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.
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From Boonsap Witchayangkoon
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Pub. on May 24th 2012
Pages: 15
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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.
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From Boonsap Witchayangkoon
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Pub. on May 24th 2012
Pages: 22
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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.
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From Boonsap Witchayangkoon
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Pub. on May 4th 2012
Pages: 10
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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.
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From Boonsap Witchayangkoon
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Pub. on May 4th 2012
Pages: 12
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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
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From Boonsap Witchayangkoon
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Pub. on May 3rd 2012
Pages: 16
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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.
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From Boonsap Witchayangkoon
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Pub. on May 4th 2012
Pages: 19
Views: 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
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From Boonsap Witchayangkoon
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Pub. on May 4th 2012
Pages: 9
Views: 1
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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...
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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.
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From Boonsap Witchayangkoon
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Pub. on Jan. 20th 2012
Pages: 15
Views: 35
Downloads: 6
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.
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From Boonsap Witchayangkoon
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Pub. on Jan. 20th 2012
Pages: 20
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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,...
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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.
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From Boonsap Witchayangkoon
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Pub. on Jan. 20th 2012
Pages: 20
Views: 15
Downloads: 1
This paper deals with the study of the carbon/metal oxide composites synthesis for electrochemical capacitor electrode material. Transition metal salts, such as FeCl3 and TiCl3 act as activator in the synthesis of activated carbon from gelam wood sawdust (Melaleuca cajuputi Powell) which also have the functions as substrates for the...
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This paper deals with the study of the carbon/metal oxide composites synthesis for electrochemical capacitor electrode material. Transition metal salts, such as FeCl3 and TiCl3 act as activator in the synthesis of activated carbon from gelam wood sawdust (Melaleuca cajuputi Powell) which also have the functions as substrates for the composites. The surface functionalities of activated carbons were modified using oxidative treatments. The changes on crystallography and surface functionalities were analyzed based on XRD and FTIR data. The electrical conductivities and electrochemical properties were determined using kelvin and cyclic voltammetry methods, respectively. FTIR analyses showed that the activation and oxidation treatments affected their surface functionalities. The XRD analyses showed that oxidative treatments also affected carbons crystallite. The electrical conductivities and electrochemical properties were influenced by their crystallite and surface functionalities. The sh
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From Boonsap Witchayangkoon
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Pub. on Jan. 18th 2012
Pages: 14
Views: 8
Downloads: 0
SS 304L, an austenitic Chromium-Nickel stainless steel offering the optimum combination of corrosion resistance, strength and ductility, is favorable for many mechanical components. The low carbon content reduces susceptibility to carbide precipitation during welding. In case of single pass welding of thinner section of this alloy,...
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SS 304L, an austenitic Chromium-Nickel stainless steel offering the optimum combination of corrosion resistance, strength and ductility, is favorable for many mechanical components. The low carbon content reduces susceptibility to carbide precipitation during welding. In case of single pass welding of thinner section of this alloy, pulsed current micro plasma arc welding was found beneficial due to its advantages over the conventional continuous current process. The paper focuses on developing mathematical models to predict grain size and hardness of pulsed current micro plasma arc welded SS304L joints. Four factors, five level, central composite rotatable design matrix is used to optimize the number of experiments. The mathematical models have been developed by response surface method. The adequacy of the models is checked by ANOVA technique. By using the developed mathematical models, grain size and hardness of the joints can be predicted with 99% confidence level. Contour plots are
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From Boonsap Witchayangkoon
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Pub. on Jan. 16th 2012
Pages: 18
Views: 4
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The aim of this work is to evaluate the wind energy potential of two sites in the Ibiapaba Mountain situated in the Ceará State, Brazil. Techniques and parameters used for the assessment of wind energy in those sites are described and statistical analysis of wind speed and direction is performed in data collected of two meteorological...
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The aim of this work is to evaluate the wind energy potential of two sites in the Ibiapaba Mountain situated in the Ceará State, Brazil. Techniques and parameters used for the assessment of wind energy in those sites are described and statistical analysis of wind speed and direction is performed in data collected of two meteorological stations. It was observed that the Ibiapaba Mountain presents significant wind energy potential and adequate to satisfy the demand for electricity at the region and consequently may be suitable to complement the energy matrix of the Ceará State.
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From Boonsap Witchayangkoon
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Pub. on Jan. 16th 2012
Pages: 19
Views: 21
Downloads: 1
This paper deals with the cyclic elastoplastic large displacement analysis and stability evaluation of steel tubular braces subjected to axial tension and compression. The inelastic cyclic performance of cold-formed steel braces made of circular hollow sections is examined through finite element analysis using the commercial computer...
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This paper deals with the cyclic elastoplastic large displacement analysis and stability evaluation of steel tubular braces subjected to axial tension and compression. The inelastic cyclic performance of cold-formed steel braces made of circular hollow sections is examined through finite element analysis using the commercial computer program ABAQUS. First some of the most important parameters considered in the practical design and ductility evaluation of steel braces of tubular sections are presented. Then the details of finite element modeling and numerical analysis are described. Later the accuracy of the analytical model employed in the analysis is substantiated by comparing the analytical results with the available test data in the literature. Finally the effects of some important structural and material parameters on cyclic inelastic behavior of steel tubular braces are discussed and evaluated.
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From Boonsap Witchayangkoon
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Pub. on Jan. 19th 2012
Pages: 16
Views: 5
Downloads: 0
This study uses Relevance Vector Machine (RVM) regression to develop a probabilistic model for the average horizontal component of 5%-damped earthquake response spectra. Unlike conventional models, the proposed approach does not require a functional form, and constructs the model based on a set predictive variables and a set of...
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This study uses Relevance Vector Machine (RVM) regression to develop a probabilistic model for the average horizontal component of 5%-damped earthquake response spectra. Unlike conventional models, the proposed approach does not require a functional form, and constructs the model based on a set predictive variables and a set of representative ground motion records. The RVM uses Bayesian inference to determine the confidence intervals, instead of estimating them from the mean squared errors on the training set. An example application using three predictive variables (magnitude, distance and fault mechanism) is presented for sites with shear wave velocities ranging from 450 m/s to 900 m/s. The predictions from the proposed model are compared to an existing parametric model. The results demonstrate the validity of the proposed model, and suggest that it can be used as an alternative to the conventional ground motion models. Future studies will investigate the effect of additional predic
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From Boonsap Witchayangkoon
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Pub. on Jan. 11th 2012
Pages: 15
Views: 10
Downloads: 0
Adsorption of reactive dye solution on nanochitin and chitin particle under acidic, neutral and basic condition was studied. The percentage adsorption of reactive dye solution on nanochitin and chitin under basic condition was 98% and 59%, respectively. In this study, we used ATR-FTIR spectroscopy to study the adsorption mechanism...
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Adsorption of reactive dye solution on nanochitin and chitin particle under acidic, neutral and basic condition was studied. The percentage adsorption of reactive dye solution on nanochitin and chitin under basic condition was 98% and 59%, respectively. In this study, we used ATR-FTIR spectroscopy to study the adsorption mechanism between nanochitin and reactive dye. The results indicated that the amine group of nanochitin was a functional group for the adsorption of Reactive Red (RR141) under acidic condition while the hydroxyl group of nanochitin was the main site for adsorption of Reactive Red (RR141) under basic condition. Azo group (N=N) of reactive dye might be electron donor, while amide group (-CONH2) of nanochitin was electron acceptor under neutral condition. XAS spectra obtained the changes of S atom in RR141 adsorbed onto nanochitin under acidic, whereas adsorption under neutral and basic condition caused no change in the form of S- atom in the dye.
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From Boonsap Witchayangkoon
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Pub. on Dec. 27th 2011
Pages: 10
Views: 5
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Young shoot tips were used as explants and cultured on MS medium supplemented with varying concentrations of (0.1, 0.5, 1.0 mg/l) BA and (0.1, 0.5, 1.0 mg/l) NAA. Calli and new shoots were grown on MS medium supplemented with combination of 0.5 mg/l BA and 0.5 mg/l NAA. New shoots averaging 0.5–0.8 cm were irradiated with varying...
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Young shoot tips were used as explants and cultured on MS medium supplemented with varying concentrations of (0.1, 0.5, 1.0 mg/l) BA and (0.1, 0.5, 1.0 mg/l) NAA. Calli and new shoots were grown on MS medium supplemented with combination of 0.5 mg/l BA and 0.5 mg/l NAA. New shoots averaging 0.5–0.8 cm were irradiated with varying doses of gamma rays (5, 10, 15, 20 grays). Gamma irradiation had various effects on growth of Torenia fournieri. Higher dosage of gamma irradiation reduced plant height, number of roots, number of leaves, leaf length, leaf width, petiole length and number of guard cells at abaxial and adaxial epidermis surface. Plant morphology and flower development was also modified.
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From Boonsap Witchayangkoon
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Pub. on Dec. 27th 2011
Pages: 9
Views: 6
Downloads: 0
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