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Ubon Ratchathani, Thailand

Poopanya P.,Ubon Ratchathani Rajabhat University
Physics Letters, Section A: General, Atomic and Solid State Physics

Electronic structures and thermoelectric properties of delafossite 2H-CuAlO2 have been theoretically investigated using first principles calculations and Boltzmann transport equation. The delafossite 2H-CuAlO2 exhibits an indirect gap of 2.2 eV and a direct gap of 3.1 eV. As the temperature increases, the electrical conductivity increases but the Seebeck coefficient decreases. However, the power factor tends to increase with temperature and dramatically increases in the case of high carrier concentration when the doping level is located near the valence band. It is also found that the dimensionless figure of merit, ZT, increases with increasing temperature. At T = 680 K, the calculated ZT are 0.007 for p-type doping and 0.0035 for n-type doping. These maximum ZT are obtained at the carrier concentration of approximately 5.0 × 1021 cm- 3 and 1.0 × 1021 cm- 3 for p-type and n-type dopings, respectively. © 2014 Elsevier B.V. All rights reserved. Source

Kanso S.,Ubon Ratchathani University | Dasri K.,Ubon Ratchathani Rajabhat University | Tingthong S.,Ubon Ratchathani University | Watanapokasin R.Y.,Srinakharinwirot University
International Journal of Hydrogen Energy

This project aimed to study the diversity of cultivable hydrogen-producing bacteria, isolated from agricultural soils, waste water sludge and cow dung by analyzing 16S rRNA gene. Isolation performed anaerobically on nutrient agar using environmental samples as inoculum yielded 106 pure isolates. These isolates were tested for their capability to produce hydrogen. Then 16S rRNA gene of the 11 isolates having such ability were PCR amplified and subjected to restriction fragment length polymorphism (RFLP) analysis in order to group them into operational taxonomic units (OTUs). RFLP was evaluated for its ability to group the 1500-1600 bp PCR products into OTUs. Isolates were presumptively identified by analysis of partial 16S rRNA gene sequence data. Each OTU was found to be phylogenetically cohesive. The 11 isolates were put into 2 main groups. Group 1 composted of WS-2-2, AS-I-1 and AS-I-2 whose partial 16S rRNA genes showed similarity of 98-99% to members of the genus Paenibacillus. Group 2 composted of WS-4-2, Lao-1-2, WS-7-11, AS-1, AS-4, CD-5 and CD-6 having highest similarity of 98-99% to members of four genera in the family Enterobacteriacea. AS-I-2 which produced the highest amount of hydrogen gas of 2.70 ml had the highest 16S rRNA gene similarity of 99% to Paenibacillus polymixa. © 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Source

Tangkawanit S.,Ubon Ratchathani Rajabhat University
Advanced Materials Research

This research was an intensive study on development of Hibiscus cannabinus L. fibers dyeing with natural dyes. The result reflected that color shade and color strength value results were different depend on type of mordanted. The Hibiscus cannabinus L. washing with detergent dyeing with Caesalpinia sappan L. and various mordented showed that light fastness was in level 3-4, when CuSO4 and FeSO4 mordanted light fastness result was in level 4-5, mordants as lime, CuSO4 and FeSO4 were added washing fastness property was in level 5. © (2013) Trans Tech Publications, Switzerland. Source

Manwong M.,Ubon Ratchathani University | Songserm N.,Ubon Ratchathani Rajabhat University | Promthet S.,Khon Kaen University | Matsuo K.,Kyushu University
Asian Pacific Journal of Cancer Prevention

Background: Cholangiocarcinoma (CCA) is the most common cancer in Northeast Thailand. It is also a crucial health problem for Thai people. Various risk factors for CCA have been identified in the upper part of Northeast Thailand, but no similar studies of risk factors have been conducted in the lower parts of the region. This study aimed to investigate factors associated with CCA in the resident population. Materials and Methods: A hospital-based case-control study was conducted during 2009-2012 with the recruitment of 123 CCA cases and 123 non-CCA patient controls, matched for sex, age and residential area. Information was collected by interview with a structured questionnaire. Blood samples were collected for assays of anti-OV antibodies. Associations between various personal factors, dietary habits, family history, the presence of anti-OV antibodies and CCA were analyzed using multiple conditional logistic regression. Results: Patients who consumed raw meat (beef, pork) and alcoholic beverages ≥3 times per week had a higher risk of CCA than non-consumers (ORadj=4.33; 95%CI=1.14-16.35 and ORadj=2.13; 95%CI=1.00-4.55, respectively). Patients who had a family history of cancer had a higher risk than those who did not (ORadj=4.34; 95%CI=1.80-10.43). Also, patients who had anti-OV antibodies (AU>23.337) had a higher risk than those whose anti-OV antibodies were below the cut-off(AU≤23.34) (ORadj=3.09; 95%CI=1.04-9.16). Conclusions: As is the case in the upper part of Northeast Thailand, OV infection is a crucial risk factor for CCA in people who live in lower part of the region. Similarly, a family history of cancer and the consumption of alcohol are risk factors for CCA. Source

Wetchakun N.,Chiang Mai University | Chainet S.,Chiang Mai University | Phanichphant S.,Chiang Mai University | Wetchakun K.,Ubon Ratchathani Rajabhat University
Ceramics International

BiVO4/TiO2 nanocomposites were successfully synthesized by coupling the modified sol-gel method with hydrothermal method. The samples were physically characterized X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer, Emmett and Teller (BET)-specific surface area, UV-vis diffuse reflectance spectrophotometry, zeta potential, and photoluminescence techniques. The BiVO4/TiO2 nanocomposites exhibited good photocatalytic activity in degradation of methylene blue under simulated solar light irradiation. The photodegradation of methylene blue demonstrated that 0.5BiVO4/0.5TiO2 photocatalyst exhibited much enhanced photoactivity than pure BiVO4 and TiO2. Based on the obtained results, the as-prepare BiVO4/ TiO2 nanocomposite possessed great adsorptivity of methylene blue, extended light adsorption range, and efficient charge separation properties. Overall, this work could provide new insights into the fabrication of a BiVO4/TiO2 composite as high performance photocatalyst and promise as a solar light photocatalyst for dye wastewater treatment. © 2015 Elsevier Ltd and Techna Group S.r.l. Source

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