Science & Technology Asia <p style="text-align: justify;">Science &amp; Technology Asia (formerly Thammasat International Journal of Science and Technology), first published in 1996, is a peer-reviewed, open access journal containing original research articles, review articles, and short communications in the fields associated with science and technology.&nbsp;Science &amp; Technology Asia aims to be a forum through which scientists and experts in the fields of science and technology share and discuss their quality research work. Original research articles as well as review articles and short communications in multidisciplinary fields of science and technology are within the scope of the journal.<br>The journal welcomes contributions in the following fields:<br>1. Biological sciences such as biology, zoology, botany, genetics, agriculture, ecology.<br>2. Engineering such as electrical engineering, chemical engineering, civil engineering, environmental engineering, computer engineering; and information technology.<br>3. Health sciences such as medicine, dentistry, veterinary, pharmacy, physical therapy, nursing, public health.<br>4. Physical sciences such as chemistry, physics, mathematics, statistics.<br>The journal publishes 4 issues per year: No.1 January-March, No.2 April-June, No.3 July-September and No.4 October-December.<br>Science &amp; Technology Asia&nbsp;is currently indexed in both national and international electronic/online databases, namely, Thai-Journal Citation Index (TCI) Tier 1, ASEAN Citation Index (ACI), Elektronische Zeitschriftenbibliothek (EZB).</p> <p style="text-align: justify;">This journal has adopted a double-blind reviewing policy whereby both the referees and author(s) remain anonymous throughout the process.</p> en-US (Wutiphol Sintunavarat) (Thanyarat Jeamklin Thammasat University (Rangsit Campus)) Mon, 21 May 2018 00:00:00 +0700 OJS 60 Optimization of Solid-Liquid Extraction of Gamma-oryzanol from Rice Bran Oil Soapstock using Soxhlet Extraction Method <p>Rice bran oil soapstock (RBOS) is a by-product from the chemical refining process of rice bran oil production. It contains a large amount of <img title="\gamma" src="\gamma">-oryzanol. The main objective of this study was to investigate the amount of <img title="\gamma" src="\gamma">-oryzanol obtained by solvent extraction using soxhlet apparatus. RBOS was saponified and was then dehydrated and extracted with ethyl acetate. The optimum conditions were determined using response surface methodology (RSM) with a Box-Behnken experimental design (BBD). BBD was used to investigate the effects of three independent variables, namely solid to solvent ratio (w/v), extraction temperature (°C), and extraction time (h). The results showed that the most suitable conditions for the extraction of RBOS that can provide the highest yield of <img title="\gamma" src="\gamma">-oryzanol (9.04% dry basis) were 1:12 solid to solvent ratio, 70.1°C extraction temperature and 7.26 h extraction time.</p> Kanitta Wangdee, Ekasit Onsaard ##submission.copyrightStatement## Mon, 21 May 2018 00:00:00 +0700 Enhanced Physical Stability of Rice Bran Oil-in-Water Emulsion by Heat and Alkaline Treated Proteins from Rice Bran and Soybean <p>The aim of this work was to improve physical stability of rice bran oil-in-water emulsion by heat and alkaline treated proteins from rice bran and soybean. Rice bran protein (RBP) was extracted from defatted rice bran by alkaline extraction and isoelectric precipitation. RBP and soy protein (SP) were modified by heat and alkaline treatment (pH 9 at 60 °C for 60 min). The ability of modified rice bran protein (MRBP) and modified soy bean protein (MSP) to stabilize rice bran-oil-in-water emulsion was investigated. Results showed that the MRBP and MSP to form and stabilize oil-in-water emulsions were better than those of RBP and SP. Emulsions with small particle sizes diameter and creaming stability could be produced at pH 6.5 for 0.4-1.0 %wt MRBP and 0.6-1.0 %wt MSP. Improved physical stability of rice bran oil-in-water emulsion by heat and alkaline treated will enhance the utilization RBP and SP as food ingredient in the food industry.</p> Rodjana Noptana, Ekasit Onsaard ##submission.copyrightStatement## Mon, 21 May 2018 00:00:00 +0700 Genetic Relationship Assessment and Identification of Strap-Leaf Paphiopedilum Using HAT-RAPD Markers <p>&nbsp;High annealing temperature - random amplified polymorphic DNA (HAT-RAPD) marker was used to identify and investigate the genetic relationship among 15 <em>Paphiopedilum</em> species of Venus slipper. The total of 72 primers was screened and 16 primers could be used for DNA amplification with clear amplified products to construct DNA fingerprints. The total of 248 polymorphic bands was found. A dendrogram, which constructed from the polymorphic bands using UPGMA by the NTSYS program, showed genetic similarities among 15 <em>Paphiopedilum</em> species with similarity coefficients ranging from 0.252 to 0.624. The orchids were classified into 3 clusters. These results indicated that the HAT-RAPD markers are capable to specify<em> Paphiopedilum</em>, and can be used in the breeding program and for genetic resource conservation in the future.&nbsp;</p> Pornprapa Siritheptawee, Somchit Damrianant, Theerachai Thanananta, Narumol Thanananta ##submission.copyrightStatement## Mon, 21 May 2018 00:00:00 +0700 Investigation of Diverse Cryopreservation Techniques for Long Term Storage of Coffee Leaf Rust Hemileia vastatrix <p>Coffee leaf rust (CLR) is the most devastating disease in coffee (<em>coffea </em>sp.) and caused by the rust fungus <em>Hemileia vastatrix</em>. Currently, there are several studies on developing disease resistance varieties. Thus, long-term live storage of <em>H. vastatrix</em> is necessary. <em>Hemileia vastatrix </em>is a biotroph pathogen, which requires nutrients from living host cells and cannot be cultivated <em>in vitro</em>. However, to continue culturing CLR in living plants is not only labor intensive, but also not cost effective. Therefore, three cryopreservation techniques and two storage temperatures were investigated on three potential CLR isolates – DC204, DC404 and DC604 – collected from Chiang Rai province, Thailand. Although, all cryopreservation techniques failed to provide long term storage of <em>H. vastatrix,</em> <em>in situ</em> cryopreservation at -20 <sup>o</sup>C showed potential for short term storage of this pathogen. Thus, this technique could be used as an alternative to <em>in</em> <em>vivo </em>culturing for maintaining pathogenic isolates in the laboratory.</p> Siraprapa Brooks, Dusit Athinuwat ##submission.copyrightStatement## Mon, 21 May 2018 00:00:00 +0700 Manifold Ambiguities in Higher-Order Statistics-based Direction-Finding Systems <p>Subspace-based direction-finding methods assume that all source’s manifold vectors<br>are linearly independent. However, when this condition is not satisfied, the estimation<br>methods will subsequently fail to identify the directions of the sources. This undesirable effect<br>is referred to as a manifold ambiguity. In this paper, the presence of manifold ambiguity<br>associated to a higher-order statistics-based array processing is investigated. By analyzing the<br>geometrical shape of the corresponding array manifold, a class of ambiguous sets based on a<br>uniform partition of the effective manifold curve can be found. A general procedure is<br>provided in order to model and categorize these ambiguities into the form of ambiguous<br>generator sets.</p> Supawat Supakwong ##submission.copyrightStatement## Mon, 21 May 2018 00:00:00 +0700 Application of the Task-Technology Fit Model to Structure and Evaluation of the Adoption of Smartphones for Online Library Systems <p>Clearly, smartphone usage is increasing more than tablet usage, thus providing opportunities to evaluate how well the use of smartphones meets the requirements of patrons in an academic library setting. This study used the task-technology fit (TTF) model to explore the effectiveness of smartphones for interacting with online library systems, the need for smartphone support, and the “fit” of the device to tasks, as well as performance. The study used interviews and survey data to identify what are the core strengths and limitations of a smartphone construct that stimulate patrons to perform their tasks in an online library setting. Using exploratory factor analysis, preliminary findings confirmed Technology-Content, Technology-Ergonomics, Technology-Smartphone Support, Technology-Platform, and Technology-Interaction design as the core dimensions of the smartphone construct. The results of the structural model supported the overall TTF model in reflecting significant positive impact of task and technology in TTF for smartphones in a digital-library setting; it also confirmed a significant positive impact of TTF on individuals’ performance.</p> Sununthar Vongjaturapat ##submission.copyrightStatement## Mon, 21 May 2018 00:00:00 +0700 Optimization of Bioethanol Production from Raw Sugar in Thailand <p>Since the increasing demand of molasses as raw material for ethanol production in Thailand, the feasibility of applying raw sugar as an alternative raw material for ethanol production is studied in this research. However, although raw sugar has higher sugar content and pure quality than molasses, raw sugar costs are higher than molasses. Thus, it is necessary to evaluate the optimum proportion of raw sugar by considering the value of fermentation efficiency by analyzing the ratio of raw sugar to molasses from 0%:100% to 100%:0%. The results showed that the mixture of raw sugar and molasses in Experiment No.1 at a ratio of 20%:80% gained the highest fermentation efficiency at 82.71%. With the addition of enzyme (Experiment No.2), it would enhance the fermentation efficiency to 84.27% at a ratio of 60%:40%. Moreover, by adding enzyme and ferment nutrients (Experiment No.3) it could enhance the fermentation efficiency to 85.98% at a ratio of 80%:20%. These results indicated that the higher amount of applying raw sugar, the more fermentation efficiency in ethanol production. Furthermore, the economic results shown that even though a ratio of 80%:20% from Experiment No.3 had the highest fermentation efficiency, a ratio of 20%:80% presented the best economic result (profit) with high fermentation efficiency (around 85%). Moreover, when the prices of raw sugar and molasses were changed, the Experiment No.3 had more appropriate operation than Experiment No.1 and No.2, because the Experiment No.3 provieded the best economic results with any conditions.</p> Woranee Mungkalasiri, Boonchuay Pan-in, Jitti Mungkalasiri ##submission.copyrightStatement## Mon, 21 May 2018 00:00:00 +0700 Adsorption of Metal-Phthalocyanine Molecule on Aluminum (100) Surface: The DFT Study <p>Adsorption of various metal-phthalocyanine (MPc) molecules on Al(100) substrate were investigated by using the Density functional Theory (DFT).&nbsp; There are six transition metal atoms substituted in phthalocyanine skeleton ranking from d<sup>5</sup> to d<sup>10</sup> of the 1<sup>st</sup> row of transition metal and metal free phthalocyanine (H<sub>2</sub>Pc) molecule were studied. After adsorption, we found that the interaction between MPc molecules and substrate depended on the central metal of MPc molecule. The interaction between the ZnPc, CuPc and NiPc molecules on Al substrate are relatively weak comparing to the adsorption of H<sub>2</sub>Pc molecule, while the CoPc, FePc, and MnPc adsorptions show stronger interaction. This work are further investigated the vacuum level shift by extracting the information from the density of state (DOS) calculation. The shift of DOS of MPc molecule effect to the charge barriers at the interface.</p> Asanee Somdee, Malliga Suewattana, Withoon Chunwachirasiri, Tanakorn Osotchan, Asawin Sinsarp ##submission.copyrightStatement## Mon, 21 May 2018 00:00:00 +0700