Science & Technology Asia <p class="Default">Science &amp; Technology Asia (formerly the International Journal of Science and Technology Thammasat), first published in 1996, is a peer-reviewed, open-access journal containing original research articles, review articles and short communications in areas related to science and technology. Science &amp; Technology Asia is a forum through which scientists and experts in the fields of science and technology share and discuss their quality research. Original research articles, as well as review articles and brief papers in multidisciplinary scientific and technological fields are included in the journal.</p> <p class="Default">The journal welcomes contributions in the following areas:</p> <p class="Default"><img title="\begin{array}{ll} \text{1.} &amp; \textbf{Physical sciences:} \\ &amp; \text{Chemistry, Physics, Mathematics and Statistics.} \\ \text{2.} &amp; \textbf{Engineering:} \\ &amp; \text{Electrical Engineering, Chemical Engineering, Civil Engineering,} \\ &amp; \text{Environmental Engineering, Computer Engineering and information technology.} \\ \text{3.} &amp; \textbf{Biological sciences:} \\ &amp; \text{Biology, Zoology, Botany, Genetics, Agriculture and Ecology.} \end{array}" src="\begin{array}{ll}&amp;space;\text{1.}&amp;space;&amp;&amp;space;\textbf{Physical&amp;space;sciences:}&amp;space;\\&amp;space;&amp;&amp;space;\text{Chemistry,&amp;space;Physics,&amp;space;Mathematics&amp;space;and&amp;space;Statistics.}&amp;space;\\&amp;space;\text{2.}&amp;space;&amp;&amp;space;\textbf{Engineering:}&amp;space;\\&amp;space;&amp;&amp;space;\text{Electrical&amp;space;Engineering,&amp;space;Chemical&amp;space;Engineering,&amp;space;Civil&amp;space;Engineering,}&amp;space;\\&amp;space;&amp;&amp;space;\text{Environmental&amp;space;Engineering,&amp;space;Computer&amp;space;Engineering&amp;space;and&amp;space;information&amp;space;technology.}&amp;space;\\&amp;space;\text{3.}&amp;space;&amp;&amp;space;\textbf{Biological&amp;space;sciences:}&amp;space;\\&amp;space;&amp;&amp;space;\text{Biology,&amp;space;Zoology,&amp;space;Botany,&amp;space;Genetics,&amp;space;Agriculture&amp;space;and&amp;space;Ecology.}&amp;space;\end{array}">&nbsp;</p> <p class="Default">The journal publishes 4 issues a year: No. 1, January-March; No. 2, April-June; No. 3, July-September; and No. 4, October-December.</p> <p class="Default">Science &amp; Technology Asia is currently indexed in national and international online and electronic databases, including the Thai-Journal Citation Index (TCI), the ASEAN CSE Index (ACI), the Elektronische Zeitschriftenbibliothek (EZB) and Scopus.</p> <p class="Default">This journal has adopted a double-blind reviewing policy whereby both the referees and author(s) remain anonymous throughout the process.</p> <p>&nbsp;</p> en-US (Wutiphol Sintunavarat) (Chatchada Thammasat University (Rangsit Campus)) Fri, 09 Aug 2019 00:00:00 +0700 OJS 60 Heat Transfer Augmentation in an Inclined Lid-Driven Triangular Enclosure Utilizing Nanofluids in Forced Convection Flows <p><span class="fontstyle0">Heat transfer enhancement in a two-dimensional inclined lid-driven triangular enclosure utilizing cu-water nanofluids is investigated for various relevant parameters. A model is developed to analyze heat transfer performance of nanofluids inside an enclosure taking into account the force convection parameter, namely Reynolds number, </span><span class="fontstyle2">Re</span><span class="fontstyle0">. The transport equations are solved numerically using the Galerkin finite element method. Comparisons with previously published work on the basis of special cases are performed and found to be in excellent agreement. Results are obtained for a wide range of parameters such as the Richardson number, </span><span class="fontstyle2">Ri</span><span class="fontstyle0">, and Reynolds number, </span><span class="fontstyle2">Re</span><span class="fontstyle0">. Copper-water nanofluids are used with Prandtl number, Pr = 6.2 and Reynolds number, </span><span class="fontstyle2">Re </span><span class="fontstyle0">is varied from 100 to 500. The streamlines, isotherm plots and the variation of the average Nusselt number at the hot surface as well as average fluid temperature in the enclosure are offered and discussed in detailed. It is observed that the force convection parameter strongly influenced the fluid flow and heat transfer in the enclosure at the considered three convective regimes. Furthermore, the variation of the average Nusselt number at the heated surface is found to increase when </span><span class="fontstyle2">Re&nbsp;</span><span class="fontstyle0">increases and average fluid temperature in the cavity decreases with the raise of </span><span class="fontstyle2">Re</span><span class="fontstyle0">.</span></p> Md. Masum Billah, Muhammad Sajjad Hossain, Md. Mustafizur Rahman, Abdur Rashid ##submission.copyrightStatement## Fri, 09 Aug 2019 00:00:00 +0700 Effect of Solvent Extraction on Phytochemical Component and Antioxidant Activity of Vine and Rhizome Ampelocissus martini <p><span class="fontstyle0">Som Kung, locally known as wild grape, belongs to the Vitaceae family and its scientific name is </span><span class="fontstyle2">Ampelocissus martini</span><span class="fontstyle0">. Its leaf, root and bark are used in traditional Thai medicine for providing relief of symptoms. In this work we studied the phytochemical and antioxidant activities of the hexane, ethyl acetate and methanol crude extracts of vines and rhizomes of </span><span class="fontstyle2">Ampelocissus martini</span><span class="fontstyle0">. Qualitative analysis of the phytochemical screening of the various extracts revealed the presence of terpenoid, flavonoid, saponin, phenolic acid and alkaloid. Total phenolic and flavonoid contents were investigated by using Folin-Ciocalteu and colorimetric aluminum chloride assays, respectively. The results showed that the methanolic extract of vines and rhizomes gave significantly higher total phenolic and flavonoid contents than the ethyl acetate and hexane extracts. In addition, the methanolic and ethyl acetate extracts of both parts had higher antioxidant activities than their hexane extracts. Positive correlation coefficients were observed (r = 0.987) between total phenolic and flavonoid contents and also (r = 0.998) between DPPH and ABTS. The present study provides evidence that solvent extracts of </span><span class="fontstyle2">A. martini </span><span class="fontstyle0">contain important bioactive compounds, especially the methanol extract, which produced a number of phytochemical compounds. Further study will isolate and identify the active compounds of vines and rhizomes from this solvent</span></p> Luksamee Vittaya, Sutee Aiamyang, Juntra Ui-eng, Sunanta Khongsai, Nararak Leesakul ##submission.copyrightStatement## Fri, 09 Aug 2019 00:00:00 +0700 Determination of Organochlorine Pesticide and Polychlorinated Biphenyl as POPs Residues in Freshwater Animals in Thailand during 2017-2018 <p>A rapid multiresidue method for the determination of 22 organochlorine pesticides and 7 polychlorinated biphenyl compounds as POPs contaminant was described. It involved the application of modified QuEChERS procedure followed by gas chromatography - electron capture detector (GC-ECD) analysis. The limits of detection (LOD) and quantification (LOQ) of the developed and validated method in fish tissue were 3 <img title="\mu" src="\mu">g/kg and 10 <img title="\mu" src="\mu">g/kg, respectively. The following validation parameters were within acceptable range: specificity and selectivity, linearity, accuracy and precision (at levels: 10, 15 and 50 <img title="\mu" src="\mu">g/kg, the recovery test values were between 70 and 120% and HorRat ≤2, except hexachlorobenzene and methoxychlor). The application of the method was verified by analyzing a total of 182 freshwater animal samples produced and collected in Thailand during 2017-2018. Detectable POPs residues were found in 1.6% (3 shrimp samples) of the animal samples. One of the positive samples was contaminated with pp’-DDE which was DDT metabolite (&lt;10 <img title="\mu" src="\mu">g/kg). Two shrimp samples presented residue of PCB-52 congener (&lt;10 and 30 <img title="\mu" src="\mu">g/kg). No sample had contamination higher than the extraneous maximum residue limit (EMRL) set by Ministry of Public Health of Thailand and Codex. Base on the most risky freshwater animal, primary risk assessment using shrimp daily intake of Thai population data has shown that DDT and PCB compounds contain in shrimp are unlikely to pose any health risk to Thai consumers.</p> Weerawut Wittayanan, Rattiyakorn Srikote, Thoranit Chaimongkol ##submission.copyrightStatement## Fri, 09 Aug 2019 00:00:00 +0700 Optimal Feeding Trajectory for an Industrial Sugar Mill Cogeneration Plant <p><span class="fontstyle0">Using an optimum dynamic scheduling plan, the formulated problem aimed to maximise daily profitability from an existing 12. 5 MW bagasse-based cogeneration plant with a steam capacity of 125 tonne/ h used for sugar refining. The optimal bagasse feed rate yielded a maximum daily profit of 838.49 USD (base case), about 5.14% higher than the conservative constant feeding bagasse into the existing plant. A sensitivity analysis of daily profit was constructed by perturbating the fuel low heating value (LHV), electricity selling rate of electric utility (</span><span class="fontstyle2">p</span><span class="fontstyle0">) and cost of electricity generation (</span><span class="fontstyle2">c</span><span class="fontstyle0">) . The maximum daily profit was insensitive to increases in LHV until this LHV was 11% lower than its base case value, which resulted in a decrease in maximum daily profit by 11%. Excessive moisture in the bagasse and the cost of generating electricity (</span><span class="fontstyle2">c</span><span class="fontstyle0">) caused lower profits, whereas the price of electricity (</span><span class="fontstyle2">p</span><span class="fontstyle0">) increased profits.</span></p> Wanwisa Skolpap, Kittiwut Kasemwong ##submission.copyrightStatement## Fri, 09 Aug 2019 00:00:00 +0700 Carcass Characteristics, Meat Quality and Eating Quality of Culled Dairy Cows <p><span class="fontstyle0">This study investigated the effect of breed and marbling score on carcass characteristics, meat quality and sensory evaluation of culled dairy cows (HFF), fattening dairy steers (HFM) and crossbred Charolais steers (CHA) with different marbling score (MBS&lt;3 and MBS≥3). Results showed that the CHA group had greater carcass weight and dressing (%) than the HFM and HFF groups. Rib-eyes area of the HFF group was smaller than the others (p&lt;0.05). HFF beef with MBS&lt;3 had higher fat content than the others (p&lt;0.05) while beef with MBS≥3 of all breeds did not differ in fat content (p&gt;0.05). At MBS&lt;3, CHA beef had higher L*and b* values than the others (p&lt;0.05), but there was no difference in L* and b* values when MBS≥3. At MBS&lt;3, CHA and HFM groups had higher WBSF than HFF group (p&lt;0.05) but at MBS≥3, there was no difference in WBSF among breeds. CHA and HFF beef had notable oleic acid content and MUFA contents (p&lt;0.05), while HFM and HFF beef had greater P/S ratio (p&lt;0.05). Sensory attributes were not affected by breeds (p&gt;0.05). It could be concluded that culled dairy cows had inferior carcass quality compared to Charolais steers and dairy steers. However, the beef of culled dairy cows had no difference in meat color, fat and protein contents in meat, shear force value, or sensory acceptability compared to the others when beef had a marbling score up to score 3. Therefore, culled dairy cows with marbling scores greater than 3 could be an alternative for producing high quality beef.</span></p> Jarunan Chainam, Yanin Opatpatanakit, Patthamawadi Kiatbenjakul, Rong-Shinn Lin, Siriporn Kiratikarnkul ##submission.copyrightStatement## Fri, 09 Aug 2019 00:00:00 +0700 Effects of Light-Emitting Diode Light Irradiance Levels on Yield, Antioxidants and Antioxidant Capacities of Indigenous Vegetable Microgreens <p><span class="fontstyle0">Light-Emitting Diode (LED) lights allow specific wavelengths to be selected. These may be associated with microgreen growth, nitrate accumulation, and synthesis of bioactive compounds</span><span class="fontstyle2">. </span><span class="fontstyle0">The objective of this study was to assess the effect of LED irradiance on the yield, antioxidant production, and antioxidant capacity of microgreens from five traditional vegetables: rat</span><span class="fontstyle2">-</span><span class="fontstyle0">tailed radish </span><span class="fontstyle2">(</span><span class="fontstyle3">Raphanus sativus </span><span class="fontstyle0">Linn var</span><span class="fontstyle2">. </span><span class="fontstyle3">caudatus </span><span class="fontstyle0">Ale</span><span class="fontstyle2">.)</span><span class="fontstyle0">, water convolvulus&nbsp;</span><span class="fontstyle2">(</span><span class="fontstyle3">Ipomoea aguatica </span><span class="fontstyle0">Forsk</span><span class="fontstyle2">)</span><span class="fontstyle0">, red holy basil </span><span class="fontstyle2">(</span><span class="fontstyle3">Ocimum sanctum </span><span class="fontstyle0">L</span><span class="fontstyle2">.)</span><span class="fontstyle0">, dill </span><span class="fontstyle2">(</span><span class="fontstyle3">Anethum graveolens </span><span class="fontstyle0">L</span><span class="fontstyle2">.)</span><span class="fontstyle0">, and lemon basil </span><span class="fontstyle2">(</span><span class="fontstyle3">O. africanum </span><span class="fontstyle0">Lour</span><span class="fontstyle2">)</span><span class="fontstyle0">. Samples were grown on a peat substrate in a controlled environment </span><span class="fontstyle2">( </span><span class="fontstyle0">8</span><span class="fontstyle2">-</span><span class="fontstyle0">12 days from sowing to harvesting, 25+2 ºC and 16-h photoperiod, 0.05% CO</span><span class="fontstyle0">2 </span><span class="fontstyle0">concentration, and 60+2% RHs)</span><span class="fontstyle2">. </span><span class="fontstyle0">Light irradiance levels of 330, 220, and 110 µmol.m</span><span class="fontstyle2">-</span><span class="fontstyle0">2</span><span class="fontstyle0">. s</span><span class="fontstyle2">-</span><span class="fontstyle0">1 </span><span class="fontstyle0">photosynthetically active flux density </span><span class="fontstyle2">(</span><span class="fontstyle0">PPFD</span><span class="fontstyle2">) </span><span class="fontstyle0">were compared, with fluorescence lighting as control</span><span class="fontstyle2">. </span><span class="fontstyle0">The different species showed different responses to irradiance levels. Irradiance at 330 µmol.m</span><span class="fontstyle2">-</span><span class="fontstyle0">2</span><span class="fontstyle0">.s</span><span class="fontstyle2">-</span><span class="fontstyle0">1 </span><span class="fontstyle0">PPFD was found to be optimal for growth and accumulation of bioactive compounds by water convolvulus, red holy basil, dill, and lemon basil microgreens, producing the greatest dry weight, total phenolic and flavonoid content, and ABTS and DPPH free radical scavenging</span><span class="fontstyle2">. </span><span class="fontstyle0">Rat</span><span class="fontstyle2">-</span><span class="fontstyle0">tailed radish microgreen was not significantly responsive to the irradiance level</span><span class="fontstyle2">. </span><span class="fontstyle0">We recommend the use of LED lighting to enhance productivity and promote higher production of bioactive compounds in indigenous vegetable microgreen cultivation.</span></p> Bhornchai Harakotr, Sophit Srijunteuk, Panumart Rithichai, Sompong Tabunhan ##submission.copyrightStatement## Fri, 02 Aug 2019 00:00:00 +0700 Relationships among Characteristics of the Wave-like Pattern of Ovarian Follicular Development in White Lamphun Cows <p><span class="fontstyle0">The aims of the current study were to characterize the pattern of ovarian follicular wave and to evaluate the relationships among length of interovulatory interval (IOI), number of follicular wave, duration of follicular growth phase, and lifespan of corpus luteum (CL) in White Lamphun cows. The dominate follicle (DF) and CL of ovulated White Lamphun cows (n=16) were scanned with an ultrasound machine and blood samples were collected from first ovulation until second ovulation. Cows with 2 follicular waves (2-wave cows) tended to have a shorter (P=0.063) length of IOI than cows with 3 follicular waves (3-wave cows). Prolonged duration of DF growth phase in first follicular wave (Wave 1) was observed more often in 2- wave cows than in 3-wave cows (P&lt;0.05). At the end of DF growth phase in Wave 1, the concentration of progesterone was greater in 2-wave cows than in 3 wave cows (P&lt;0.05). The 2-wave cows had a shorter length of luteal phase than 3-wave cows (P&lt;0.05). The length of IOI was positively correlated with number of follicular wave (P&lt;0.05) and length of luteal phase (P&lt;0.01) but was negatively related with duration of DF growth phase in Wave 1 (P&lt;0.05). These results demonstrate that short length of IOI in 2-wave cows is due to extended duration of DF growth phase in Wave 1 and short lifespan of CL. These data emphasized that length of IOI increased linearly with high number of follicular wave and extended lifespan of CL but decreased linearly with prolonged duration of DF growth phase in Wave 1.</span></p> Punnawut Yama, Maslin Osathanunkul, Jakree Jitjumnong, Wilasinee Pirokad, Warittha U-krit, Warunya Chaikol, Tossapol Moonmanee ##submission.copyrightStatement## Fri, 09 Aug 2019 00:00:00 +0700 Molecular Analysis of Dihydrofolate Reductase and Dihydropteroate Synthase Genes of Plasmodium falciparum Field Isolates from Afgoi and Balad, Southern Somalia <p><span class="fontstyle0">This study aimed to investigate the prevalence of the </span><span class="fontstyle2">pfdhps </span><span class="fontstyle0">and </span><span class="fontstyle2">pfdhfr&nbsp;</span><span class="fontstyle0">polymorphisms in southern Somalia. The genetic polymorphisms of both genes were analyzed by nested PCR-RFLP. A total of 150 samples were collected; of these, 101 were shown to be positive for </span><span class="fontstyle2">Plasmodium </span><span class="fontstyle0">(96 </span><span class="fontstyle2">P. falciparum </span><span class="fontstyle0">and 5 </span><span class="fontstyle2">P. vivax</span><span class="fontstyle0">) by nested PCR, the remaining 49 were PCR negative. Of the 96 </span><span class="fontstyle2">Plasmodium falciparum </span><span class="fontstyle0">isolates, 88 were successfully amplified for </span><span class="fontstyle2">pfdhps </span><span class="fontstyle0">and </span><span class="fontstyle2">pfdhfr </span><span class="fontstyle0">polymorphisms. The mutations occurring in the pyrimethamine resistance gene (</span><span class="fontstyle2">pfdhfr</span><span class="fontstyle0">) at codons 51, 59 and 108 were 59 (67.0%), 51 (58.0%) and 83 (94.3%) isolates, respectively. Sulfadoxine resistance-associated mutations in the </span><span class="fontstyle2">pfdhps </span><span class="fontstyle0">gene at codons 437, 540 and 581 were found in 41 (46.6%), 43 (48.9%) and 13 (14.8%) samples, respectively. The analysis of </span><span class="fontstyle2">pfdhfr </span><span class="fontstyle0">and </span><span class="fontstyle2">pfdhps </span><span class="fontstyle0">combination revealed that 27 (30.7%) isolates harbor the quintuple mutations (</span><span class="fontstyle3">I</span><span class="fontstyle0">51&nbsp;</span><span class="fontstyle3">R</span><span class="fontstyle0">59&nbsp;</span><span class="fontstyle3">N</span><span class="fontstyle0">108&nbsp;</span><span class="fontstyle3">- G</span><span class="fontstyle0">437&nbsp;</span><span class="fontstyle3">E</span><span class="fontstyle0">540&nbsp;</span><span class="fontstyle0">A</span><span class="fontstyle0">581 </span><span class="fontstyle0">and </span><span class="fontstyle3">I</span><span class="fontstyle0">51&nbsp;</span><span class="fontstyle3">R</span><span class="fontstyle0">59&nbsp;</span><span class="fontstyle3">N</span><span class="fontstyle0">108 -&nbsp; G<span class="fontstyle1">437</span><span class="fontstyle1">K</span><span class="fontstyle1">540</span>G<span class="fontstyle1">581</span><span class="fontstyle1">).&nbsp; The prevalence of single mutation, triple mutations, quadruple mutations and double mutations haplotypes were 19.3%, 18.2%, 15.9% and 12.5%, respectively. Additionally, sextuple mutations were observed at 2 isolates (2.3%). This study shows that the <span class="fontstyle2">pfdhfr/pfdhps </span>mutant alleles have moderately declined compared to a previous study, but still remain high. </span></span></p> Abdifatah Abdullahi Jalei, Wanna Chaijaroenkul ##submission.copyrightStatement## Fri, 09 Aug 2019 00:00:00 +0700