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Nakhon Si Thammarat, Thailand

Thubsuang U.,Walailak UniversityNakhon Si Thammarat | Sukanan D.,Chulalongkorn University | Sahasithiwat S.,National Metal and Materials Technology Center | Wongkasemjit S.,Chulalongkorn University | Chaisuwan T.,Chulalongkorn University
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2015

Abstract Gas sensing composites were fabricated using polybenzoxazine-based activated carbon aerogel as a conductive filler. The activated carbon aerogel is a nano-porous material, which has high pore volume of 0.57 cm3/g and surface area of 917 m2/g. The activated carbon aerogel/polybutadiene composite displayed good response of 11.2 and 6.7 to toluene and n-hexane, respectively, compared to those of graphite/polybutadiene composite. The activated carbon aerogel/polybutadiene composite also showed high sensitivity of 3.09 × 102 ppm-1 to toluene. However, the sensitivity of activated carbon aerogel/polybutadiene composite drastically decreased to 1.99 ppm-1 and zero when exposed to acetone and water, respectively. Contrarily, when polyvinyl alcohol was used as a matrix, the sensitivity was about 4.19 ppm-1 to water. While the composite was found to be not sensitive to toluene. The activated carbon aerogel/polybutadiene composite also showed good recovery as the electrical resistance came back to the original value within minutes when exposed to nitrogen gas. © 2015 Elsevier B.V. Source


Kongkeaw S.,Kasetsart University | Riebroy S.,Kasetsart University | Chaijan M.,Walailak UniversityNakhon Si Thammarat
Chiang Mai Journal of Science | Year: 2015

Chemical composition, phenolic compounds and antioxidant activities of brown perilla and white perilla seeds were comparatively studied. Brown perilla seed had higher protein, fat, ash and crude fiber contents than those of white perilla seed (p<0.05). Additionally, brown perilla seed contained greater contents of Ca, Mg, and P than those of white perilla seed (p<0.05). However, no difference in Fe content was found in both seeds (p>0.05). Brown perilla seed was rich in polyunsaturated fatty acid, in particular γ-linolenic acid and α-linolenic acid. The most abundant of β-carotene and α-tocopherol was found in brown perilla seed. Higher total phenolic, total flavonoid, and total flavonol contents together with higher 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2’-azino-bis(3-ethylbenzthiazoline- 6-sulphonic acid) (ABTS)-radical scavenging activities as well as a greater reducing capacity were observed in brown perilla seed extract (p<0.05). Therefore, brown perilla seed can be a good source of both macro- and micro-nutrients with phytochemical antioxidant activity. © 2015, Chiang Mai University. All rights reserved. Source


Jijai S.,Yala Rajabhat University | Siripatana C.,Walailak UniversityNakhon Si Thammarat | O-Thong S.,Thaksin UniversityPhatthalung | Ismail N.,Universiti Sains Malaysia
Jurnal Teknologi | Year: 2016

The three identical lab-scale upflow anaerobic sludge blanket (UASB) reactors were operated continuously for treating cannery seafood wastewater at seven hydraulic retention times (HRTs) of 5, 4, 3, 2, 1, 0.5 and 0.25 days. The different of granule sizes from three sources: a cassava factory (CS), a seafood factory (SS), and a palm oil mill (PS), average sizes in the range 1.5-1.7, 0.7-1.0 and 0.1-0.2 mm respectively were used as inocula for anaerobic digestion. The UASB-R1 used only granules from seafood factory (R1-SS), the UASB-R2 used mixed granules from seafood with cassava factory (R2-SS+CS) and the UASB-R3 used mixed granules from seafood factory with palm oil mill (R3-SS+PS). In this study selected mathematical models including Monod, Contois, Grau second-order and modified Stover-Kicannon kinetic models were applied to determine the substrate removal kinetics of UASB reactor. Kinetic parameters were determined through linear regression using experimental data obtained from the steady-state experiment and subsequently used to predict effluent COD. The results showed that Grau second-order and modified Stover-Kicannon kinetic models were more suitable than that of others for predicting the effluent COD, with high the correlation coefficient (R2). In addition, the UASB-R2 from mixed granules with cassava factory (SS+CS) gave the best performance and highest coefficient value. © 2016 Penerbit UTM Press. All rights reserved. Source


Nontasit N.,Walailak UniversityNakhon Si Thammarat | Kanlayanapaphon C.,Walailak UniversityNakhon Si Thammarat | Mekanawakul M.,Walailak UniversityNakhon Si Thammarat
Walailak Journal of Science and Technology | Year: 2015

Taxonomic studies and traditional uses of Zingiberaceae were conducted in Khao Luang National Park from March 2011 to March 2012, in order to study species diversity, ecology, distribution, and uses. Plant samples were collected from 6 waterfalls in the southern part of the park. Thirty-four species in 10 genera, 3 tribes of Zingiberaceae were collected. A key to species for each genus is provided. Four taxa could not yet be identified. Ka Rome waterfall has the highest number of Zingiberaceae species (23 species in 10 genera, H’ = 3.091, D’ = 0.948) because this area may be less disturbed. Some areas of the park were degraded and changed to plantations, such as Wang Mai Pak waterfall, which has the lowest number of species (13 species in 7 genera, H’ = 2.432, D’ = 0.904). Information on traditional uses of the collected plants was gathered by interviewing villagers and folks who live nearby the areas. Zingiberaceae plants are found to be important natural resources for villagers and mostly used as medicines, foods, drinks, and ornaments. © 2015, Walailak University. All rights reserved. Source


Aung-Aud-Chariya A.,Rajamangala University of Technology at Srivijaya | Aung-Aud-Chariya A.,Walailak UniversityNakhon Si Thammarat | Bangrak P.,Walailak UniversityNakhon Si Thammarat | Lumyong S.,Chiang Mai University | And 3 more authors.
Jundishapur Journal of Microbiology | Year: 2015

Background: Boletus griseipurpureus Corner, an edible mushroom, is a putative ectomycorrhizal fungus. Currently, the taxonomic boundary of this mushroom is unclear and its bitter taste makes it interesting for evaluating its antibacterial properties. Objectives: The purpose of this study was to identify the genetic variation of this mushroom and also to evaluate any antibacterial activities. Materials and Methods: Basidiocarps were collected from 2 north-eastern provinces, Roi Et and Ubon Ratchathani, and from 2 southern provinces, Songkhla and Surat Thani, in Thailand. Genomic DNA was extracted and molecular structure was examined using the RNA polymerase II (RPB2) analysis. Antibacterial activities of basidiocarp extracts were conducted with Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29523 and methicillin-resistant Staphylococcus aureus (MRSA) 189 using the agar-well diffusion method. Results: All the samples collected for this study constituted a monophyletic clade, which was closely related with the Boletus group of polypore fungi. For the antibacterial study, it was found that the crude methanol extract of basidiomes inhibited the growth of all bacteria in vitro more than the crude ethyl acetate extract. Conclusions: Basidomes collected from four locations in Thailand had low genetic variation and their extracts inhibited the growth of all tested bacteria. The health benefits of this edible species should be evaluated further. © 2015, Ahvaz Jundishapur University of Medical Sciences. Source

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