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Suksabye P.,Suan Dusit Rajabhat University | Thiravetyan P.,King Mongkut's 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.

Krisnangkura K.,King Mongkut's University of Technology Thonburi | Sansa-Ard C.,King Mongkut's University of Technology Thonburi | Aryusuk K.,King Mongkut's 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.

Chootrakool H.,Suan Dusit Rajabhat University | Shi J.Q.,Newcastle University | Yue R.,Shanghai Normal University
Statistics in Medicine | Year: 2011

Multi-arm trials meta-analysis is a methodology used in combining evidence based on a synthesis of different types of comparisons from all possible similar studies and to draw inferences about the effectiveness of multiple compared-treatments. Studies with statistically significant results are potentially more likely to be submitted and selected than studies with non-significant results; this leads to false-positive results. In meta-analysis, combining only the identified selected studies uncritically may lead to an incorrect, usually over-optimistic conclusion. This problem is known asbiselection bias. In this paper, we first define a random-effect meta-analysis model for multi-arm trials by allowing for heterogeneity among studies. This general model is based on a normal approximation for empirical log-odds ratio. We then address the problem of publication bias by using a sensitivity analysis and by defining a selection model to the available data of a meta-analysis. This method allows for different amounts of selection bias and helps to investigate how sensitive the main interest parameter is when compared with the estimates of the standard model. Throughout the paper, we use binary data from Antiplatelet therapy in maintaining vascular patency of patients to illustrate the methods. © 2011 John Wiley & Sons, Ltd.

Watthananon J.,Suan Dusit Rajabhat University | Mingkhwan A.,King Mongkut's 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.

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.

Phiwma N.,Suan Dusit Rajabhat University | Sanguansat P.,Panyapiwat Institute of Management
International Arab Journal of Information Technology | Year: 2014

In this paper, we propose new methods for feature extraction and soft majority voting to adjust efficiency and accuracy of music retrieval. For our work, the input is humming sound which is sound wave and Musical Instrument Digital Interface (MIDI) is used as the reference song in database. A critical issue of humming sound are variation such as duration, sound, tempo, key, and noise interference from both environment and acquisition instruments. Besides all the problems of humming sound we have mentioned earlier, whether humming sound and MIDI in different domain which will make the difficulty for two domains to compare each other. However, to make these two in the same domain, we convert them into the frequency domain. Our approach starts from pre-processing by using features for note segmentation by humming sound. The process consists of four steps as follows: Firstly, the MIDI is already a sequence of pitch while the pitch in humming sound is needed to extract by Subharmonic-to-Harmonic (SHR). Subsequently, the extracted pitch can be used to calculate all above attributes and then multiple classifiers are applied to classify the multiple subsets of these features. Afterwards, the subset contain the multiple attributes, Multi-Dimensional Dynamic Time Warping (MD-DTW) is used for similarity measurement. Finally, Nearest Neighbours (NN) and soft majority voting are used to obtain the retrieval results in case of equal scores. From the experiments, to achieve 100% accuracy rate at the early top-n rank in retrieving, the appropriate feature set should consist of five classifiers.

Subsorn P.,Suan Dusit Rajabhat University | Limwiriyakul S.,Edith Cowan University
Procedia Engineering | Year: 2012

Internet technology has influenced everyday life during the past few decades because of its capability to assist and enhance operational and managerial performance in both non-business and business industries. Furthermore, security issues have become more common nowadays in internet technology particularly on internet banking systems due to the harmful impact on confidentiality, integrity and privacy of the bank and its customers. In the previous research, we investigated the internet banking security system of 16 selected Australian banks. The findings from that research revealed that there were deficiencies in internet banking security in all 16 of the selected Australian banks which were likely to affect the confidentiality of the existing and potential customers of the banks. The aim of this paper was to further the scope of the research by investigating internet banking security in another country. It examined 12 Thai commercial banks and compared the results/findings obtained from the previous research paper to generate a feasible guideline for Thai commercial banks. The investigation revealed that there was a distinct lack of internet banking security information provided on all the selected Thai banks' websites as compared to the selected Australian banks which provided better internet banking security information. © 2010 Published by Elsevier Ltd.

Panichakul T.,Suan Dusit Rajabhat University | Payuhakrit W.,Mahidol University | Panburana P.,Mahidol University | Wongborisuth C.,Mahidol University | And 2 more authors.
Malaria Journal | Year: 2012

Background: Severe anaemia due to dyserythropoiesis has been documented in patients infected with Plasmodium vivax, however the mechanism responsible for anaemia in vivax malaria is poorly understood. In order to better understand the role of P. vivax infection in anaemia the inhibition of erythropoiesis using haematopoietic stem cells was investigated. Methods: Haematopoietic stem cells/CD34 + cells, isolated from normal human cord blood were used to generate growing erythroid cells. Exposure of CD34 + cells and growing erythroid cells to P. vivax parasites either from intact or lysed infected erythrocytes (IE) was examined for the effect on inhibition of cell development compared with untreated controls. Results: Both lysed and intact infected erythrocytes significantly inhibited erythroid growth. The reduction of erythroid growth did not differ significantly between exposure to intact and lysed IE and the mean growth relative to unexposed controls was 59.4 ± 5.2 for lysed IE and 57 ± 8.5% for intact IE. Interestingly, CD34 + cells/erythroid progenitor cells were susceptible to the inhibitory effect of P. vivax on cell expansion. Exposure to P. vivax also inhibited erythroid development, as determined by the reduced expression of glycophorin A (28.1%) and CD 71 (43.9%). Moreover, vivax parasites perturbed the division of erythroid cells, as measured by the Cytokinesis Block Proliferation Index, which was reduced to 1.35 ± 0.05 (P-value≤0.01) from a value of 2.08 ± 0.07 in controls. Neither TNF-a nor IFN-g was detected in the culture medium of erythroid cells treated with P. vivax, indicating that impaired erythropoiesis was independent of these cytokines. Conclusions: This study shows for the first time that P. vivax parasites inhibit erythroid development leading to ineffective erythropoiesis and highlights the potential of P. vivax to cause severe anaemia. © 2012 Panichakul et al.; licensee BioMed Central Ltd.

Phoohinkong W.,Suan Dusit Rajabhat University | Sukonket T.,Suan Dusit Rajabhat University
Key Engineering Materials | Year: 2016

Nano-sized manganese oxide particles are attracted considerable interest in many industry areas especially in energy storage device applications because of their unique properties. For industry large scale synthesis, it needs a simple and low energy technique for scaling up production process. In this work, nano-sized manganese oxide particles were prepared via a solid-state reaction route at room temperature. The products were characterized by field emission scanning electron microscopy (FE-SEM) coupled with energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction infrared spectroscopy (XRD), and raman spectroscopy. The results show that the sizes of particles were smaller than 50 nm with narrow size distribution and high yield were obtained. In addition, this technique may be applicable to industry production of nano-sized manganese oxide or nano-sized manganese oxide composite. © 2016 Trans Tech Publications, Switzerland.

Binwahlan M.S.,Yemen University of Science and Technology | Salim N.,University of Technology Malaysia | Suanmali L.,Suan Dusit Rajabhat University
Information Processing and Management | Year: 2010

High quality summary is the target and challenge for any automatic text summarization. In this paper, we introduce a different hybrid model for automatic text summarization problem. We exploit strengths of different techniques in building our model: we use diversity-based method to filter similar sentences and select the most diverse ones, differentiate between the more important and less important features using the swarm-based method and use fuzzy logic to make the risks, uncertainty, ambiguity and imprecise values of the text features weights flexibly tolerated. The diversity-based method focuses to reduce redundancy problems and the other two techniques concentrate on the scoring mechanism of the sentences. We presented the proposed model in two forms. In the first form of the model, diversity measures dominate the behavior of the model. In the second form, the diversity constraint is no longer imposed on the model behavior. That means the diversity-based method works same as fuzzy swarm-based method. The results showed that the proposed model in the second form performs better than the first form, the swarm model, the fuzzy swarm method and the benchmark methods. Over results show that combination of diversity measures, swarm techniques and fuzzy logic can generate good summary containing the most important parts in the document. © 2010 Elsevier Ltd. All rights reserved.

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