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Bangkok, Thailand

Watthananon J.,Suan Dusit Rajabhat University | Mingkhwan A.,King Mongkuts University of Technology Bangkok
Procedia Engineering | Year: 2012

A knowledge map is a technique that increasing efficiency of an explaining associations of knowledge bodies with the purpose of managing knowledge in an organization by creating similar content associations. The most commonlyused algorithm is the prediction using association rules. However, this technique sometimes produced unsatisfactory results because the retrieved information hardly met the demand and could not explain associations of information contents to users deriving in less accessibility to knowledge. This research presents methods of explaining knowledge associations using a knowledge map, and estimating an appropriate association value for each piece of information. The value was then computed to find an assembly point of multiple-relation knowledge. A comparison, in which 1,000 academic articles represented knowledge stored in an organization, revealed that the method of explaining associations hidden in the contents using the knowledge map yielded similar and more detailed prediction values compared to the method of defining categories from knowledge topics. This enabled users to see associations of knowledge in an organization and gave them access to knowledge stored within a knowledge base, consequently stimulating a knowledge spiral and integrated knowledge in a simple and effective manner. © 2010 Published by Elsevier Ltd. Source


Waranusantigul P.,Suan Dusit Rajabhat University | Waranusantigul P.,Mahidol University | Lee H.,University of Guelph | Kruatrachue M.,Mahidol University | And 2 more authors.
Chemosphere | Year: 2011

In this study, the potential of rhizospheric bacteria in promoting the growth and Pb accumulation by the woody plant Eucalyptus camaldulensis under hydroponic conditions was investigated for the first time. Three Pb-tolerant bacteria were isolated from the rhizosphere of E. camaldulensis grown in Pb-contaminated soils in the Bo Ngam Pb mine, Thailand. Based on analysis of partial 16S rRNA gene sequence, the three isolates were identified as Microbacterium paraoxydans BN-2, Ochrobactrum intermedium BN-3, and Bacillus fusiformis BN-4. Among these strains, O. intermedium BN-3 showed the highest tolerance to not only Pb but also Cd and Zn. After growth in the presence of Pb, the membranes of O. intermedium BN-3 cells exhibited an increase in unsaturated fatty acid levels but a decrease in fluidity. In hydroponic studies, inoculation of O. intermedium BN-3 significantly increased the biomass and Pb accumulation by E. camaldulensis compared to the uninoculated control. The results suggested the role of the natural rhizospheric bacteria localized to the root surface of E. camaldulensis in promoting Pb accumulation and plant growth. Our results indicate that O. intermedium BN-3 and other indigenous rhizospheric bacteria have the potential to improve the efficiency of phytoremediation of Pb-contaminated sites. © 2011 Elsevier Ltd. Source


Suksabye P.,Suan Dusit Rajabhat University | Thiravetyan P.,King Mongkuts University of Technology Thonburi
Journal of Environmental Management | Year: 2012

Coir pith samples were chemically modified by grafting with acrylic acid for the removal of Cr(VI) from electroplating wastewater. The presence of acrylic acid on the coir pith surface was verified by a scanning electron microscope with an electron dispersive x-ray spectrometer (SEM/EDX), Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TG). The carbonyl groups (CO) from the carboxylic acids (COOH) increased on the coir pith surface after grafting with acrylic acid. In addition, the thermal stability of the acrylic acid-grafted coir pith also improved. The optimum conditions for grafting the acrylic acid on the coir pith consisted of 2 M acrylic acid and 0.00125 M ceric ammonium nitrate (CAN, as an initiator). The maximum Cr(VI) removal (99.99 ± 0.07%) was obtained with the following conditions: a 1.3% (w/v) dosage of acrylic acid-grafted coir pith, a system pH of 2, a contact time of 22 h, a temperature of 30 °C, a particle size of <150 μm and an initial Cr(VI) of 1,171 mg l -1. At system pH of 2, Cr(VI) in the HCrO4- form can be adsorbed with acrylic acid-grafted coir pith via an electrostatic attraction. The adsorption isotherm of 2 M acrylic acid-grafted coir pith exhibited a good fit with the Langmuir isotherm. The maximum Cr(VI) adsorption capacity of the 2 M acrylic acid-grafted coir pith was 196.00 mg Cr(VI) g -1 adsorbent, whereas for coir pith without grafting, the maximum Cr(VI) removal was 165.00 mg Cr(VI) g -1 adsorbent. The adsorption capacity of the acrylic acid-grafted coir pith for Cr(VI) was higher compared to the original coir pith. This result was due to the enhancement of the carbonyl groups on the coir pith surface that may have involved the mechanism of chromium adsorption. The X-ray absorption near edged structure (XANES) and desorption studies suggested that most of the Cr(III) that presented on the acrylic acid-grafted coir pith was due to the Cr(VI) being reduced to Cr(III) on the adsorbent surface. FTIR confirmed the involvement of the carbonyl groups (CO) and the methoxy groups (OCH 3) in the mechanism of chromium adsorption. Thermodynamic study, such as enthalpy (ΔH), free energy (ΔG) and entropy change (ΔS) indicated that the overall adsorption process was endothermic, spontaneous and randomness. In addition, the adsorption process was favored at high temperatures. © 2012 Elsevier Ltd. Source


Mutchima P.,Suan Dusit Rajabhat University | Sanguansat P.,Panyapiwat Institute of Management
2012 IEEE International Conference on Signal Processing, Communications and Computing, ICSPCC 2012 | Year: 2012

Determination of content importance is very important in achieving high quality classification. Term weighting schemes in text classification will be applied to classify videos by measuring importance of video contents. In other words, a video sequence can be treated as a document, and frames of a video are considered as words or terms which identify contents of a video. And to enhance the efficiency of video classification, this paper proposes a novel term weighting scheme, called the Term Frequency - Relevance and Non-relevance Frequency (TF-RNF) weighting. This technique can filter both relevant and non-relevant contents so as to reduce classification errors. Empirical evaluations of results show that the proposed technique significantly outperforms traditional techniques in sports video classification. © 2012 IEEE. Source


Krisnangkura K.,King Mongkuts University of Technology Thonburi | Sansa-Ard C.,King Mongkuts University of Technology Thonburi | Aryusuk K.,King Mongkuts University of Technology Thonburi | Lilitchan S.,Mahidol University | Kittiratanapiboon K.,Suan Dusit Rajabhat University
Fuel | Year: 2010

Kinematic viscosity (η) is an important property of diesel fuels, including biodiesels, which are marketed mostly as the blends in many countries around the world. In this study, the free energy of viscous flow (ΔG vis) for a non-associated liquid mixture is assumed to be the summed of ΔGvis of individual components. Hence, the Eyring's equation, η = Ae(-ΔGvis/RT), is transformed to ln ηblend = a + bn1 + c/T + dn1/T (where, a, b, c and d, T and n1 are thermodynamically related constants, absolute temperature and mole fraction of biodiesel, respectively). The transformed equation is used to predict kinematic viscosity of biodiesel blends (ηblend) of different degree of blending at any temperatures from pour point to 100 °C. The predicted kinematic viscosities are in good agreement with those reported in literatures at all temperatures. The highest deviation is ±5.4% and the average absolute deviation (AAD) is less than 2.86%. The transformed equation can also be used to predict kinematic viscosities of pure fatty acid methyl esters in diesel fuel. Methyl ricinoleate is an exception. The AAD is 4.50% and the deviation is as high as 12.80%. The high deviation suggests that molecular interactions between methyl ricinoleate and diesel fuel is high and cannot be ignored. © 2009 Elsevier Ltd. All rights reserved. Source

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