Leevijit T.,Prince of Songkla University |
Prateepchaikul G.,Prince of Songkla University |
Maliwan K.,Prince of Songkla University |
Mompiboon P.,Nakhon Si Thammarat Rajabhat University |
Eiadtrong S.,Prince of Songkla University
Renewable Energy | Year: 2017
The production, property, and utilization of un-preheated degummed/esterified mixed crude palm oil (DgMCPO/EMCPO)-diesel blends in an agricultural engine were studied. The results reveal that DgMCPO and EMCPO can be produced easily with costs comparable to diesel. They had a poor liquid phase and high viscosity. Through blending with diesel at maximum portions of 20 vol% (DgMCPO20) and 30 vol% (EMCPO30), clear liquid blends were produced. Almost important fuel properties of these blends met Thailand agricultural engine diesel standard with slightly higher densities and viscosities than diesel, significantly higher oxygen content than diesel, good cetane numbers, and slightly lower heating values than diesel. At 2200 rpm under loads in the range of 1.28–5.6 kW, un-preheated blends were able to well operate the engine as same as diesel. Comparing this with diesel; the blends resulted in slightly higher brake specific fuel consumptions (+4.5% and +5.0%), slightly lower brake thermal efficiencies (−0.9% and −1.2%), significantly lower levels of carbon monoxide (−33.7% and −33.2%), slightly lower exhaust gas temperatures (−5.1% and −5.5%), and significantly higher levels of nitrogen oxides (+8.9% and +15.9%); (all paired values, DgMCPO20 and EMCPO30 respectively). In conclusion, these blends are recommended as effective diesel substitutes for use in agricultural engines. © 2016 Elsevier Ltd
Ninwong B.,Nakhon Si Thammarat Rajabhat University |
Dungchai W.,King Mongkut's University of Technology Thonburi
Asian Journal of Chemistry | Year: 2014
A colorimetric method has been developed for determination of Fe(II) by paper-based microfluidic devices (μPADs). The analytical device is easily constructed using wax-printing on filter paper with was indicated that hydrophobic zone. Fe(II) was detected by the reaction of Fe(II) and 1,10-phenanthroline which the red/orange ferroin complex [Fe(phen)3]2+ was formed. Under the optimum conditions, the linear range between the color intensity and the concentration were found to be 0.1-3.5 and 3.5-15 mg L-1, but with a different slope. The limits of detection were obtained at the concentrations as low as 0.07 mg L-1. The proposed method can be successfully applied to the determination of Fe(II) in drinking water sample. The recoveries were in the range 86.60-109.80 %. The present procedure provides rapid, sensitive and selective for detection of Fe(II), minimal reagent consumption, low cost, thus it is suitable for on-site environmental monitoring. © 2014, Chemical Publishing Co. All rights reserved.
Saengsane N.,Nakhon Si Thammarat Rajabhat University
Asian Journal of Chemistry | Year: 2014
Momordica subangulata Blume is a plant which belongs to the Cucurbitaceae family. It can be used as herbs and only found in the South of Thailand, especially in Nakhon Si Thammarat. There are no such a report on its antioxidant activity and total phenolic content. The study aims to determine and compare total phenolic content and antioxidant activity in different parts of the plant including its leaves, roots, vines, pulp, barks and seeds. The DPPH assay and the Folin-Ciocalteu assay were applied for determining antioxidant activity and total phenolic content. The methanol extract of dried barks contained the highest antioxidant activity (IC50 = 10.85 ± 1.13 mg/L) followed by seeds, pulp, roots, leaves and vines. While the highest phenolic content in total was present in methanol extracts of M. subangulata dried leaves (80 ± 1.46 mg GAE/100 g DW). The results suggest that the plant of M. subangulata is a good natural source of antioxidants and the further studies on their pharmacological properties should be undertaken. © 2014, Chemical Publishing Co. All rights reserved.
Porrawatkul P.,Nakhon Si Thammarat Rajabhat University |
Pimsen R.,Nakhon Si Thammarat Rajabhat University
Asian Journal of Chemistry | Year: 2014
Myristica fragrants (nutmeg) is a tropical fruit in Banda Island. It is also used to cultivate in the South of Thailand. It is used as conventional medicine for disease prevention and treatment. However, there are no research studies about its antioxidant activities using ethanol solvent. The total phenolic content and antioxidant capacity in different parts of ethanolic extract (pulp, mace and seed) from nutmeg were evaluated. Dried samples were extracted using 95 % ethanol, while Folin-Ciocalteu assay was employed to determine total phenolic content. Whereas, antioxidant activities were determined by ferric reducing antioxidant power and DPPH assay. The results revealed that the nutmeg seed contained the highest total phenolic content, which was 465.91 ± 03 mg GAE/100 g DW. For antioxidant activity, the nutmeg seed possessed the highest inhibited DPPH (IC50 = 4.6 ± 15 mg/L) and the highest ferric reducing antioxidant power values (542.39 ± 22 μmol TE/100 gDW), which were significantly higher than reference standard. Phenolic compounds in nutmeg samples have exhibited strong correlation with antioxidant capacity. Therefore, nutmeg, especially nutmeg seed is potentially functional food with high antioxidants. © 2014, Chemical Publishing Co. All rights reserved.
Rittirat S.,Nakhon Si Thammarat Rajabhat University |
Klaocheed S.,Prince of Songkla University |
Thammasiri K.,Mahidol University
Acta Horticulturae | Year: 2015
Protocorm-like bodies (PLB) of Phalaenopsis cornu-cervi (Breda) Blume &Rchb. f. derived from wounded protocorm segments culturing on =Murashige and Skoog, 1962 (MS) medium containing 0.1 mg/L NAA and 0.1 mg/L TDZ. Encapsulation of the PLB using 3% sodium alginate and 100 mM calcium chloride dissolved in ND liquid medium supplemented 2% (w/v) sucrose. Among the three temperature regimes of storage (4±1°C, 8±1°C, 25±1°C), encapsulated PLB stored at 25±1°C, for 30 days showed maximum percentage of germination at 100 when culture on ND medium supplemented with 4% (w/v) sucrose with 0.2% (w/v) activated charcoal (AC). Plantlets regenerated from capsules were acclimatized successfully with 100% survival rate. Morphological characteristics of those plantlets were normal and ploidy level was the same as controlled plantlets as revealed by flow cytometry.
Pimsen R.,Chulalongkorn University |
Pimsen R.,Nakhon Si Thammarat Rajabhat University |
Khumsri A.,Chulalongkorn University |
Wacharasindhu S.,Chulalongkorn University |
And 2 more authors.
Biosensors and Bioelectronics | Year: 2014
Widespread use of dichlorvos in agriculture has posed serious concern for food and water contamination. A new colorimetric method for the detection of dichlorvos based on polydiacethylene and acetylcholinesterase inhibition is developed. The blue-to-red color transition of poly(10,12-pentacosadynoic acid) vesicles can be induced by myristoylcholine which is enzymatically hydrolyzed by acetylcholinesterase to myristic acid and choline to prevent the color transition. In the presence of dichlorvos, the hydrolytic activity of the enzyme is inhibited that the blue-to-red color transition is restored with a linear correlation to the dichlorvos concentration. Using UV-vis absorption spectrometer, the limit of dichlorvos detection is 6.7. ppb. A naked eye detection of 50. ppb dichlorvos is achievable by using dimiristoylphosphatidylcholine to the diacetylene mixed lipid vesicles. © 2014 Elsevier B.V.
Boonklong O.,Nakhon Si Thammarat Rajabhat University |
Bhumiratana A.,Thammasat University
Canadian Journal of Infectious Diseases and Medical Microbiology | Year: 2016
Using GIS-based land use map for the urban-rural division (the relative ratio of population density adjusted to relatively Aedes-infested land area), we demonstrated significant independent observations of seasonal and geographical variation of Aedes aegypti and Aedes albopictus vectors between Muang Narathiwat district (urban setting) and neighbor districts (rural setting) of Narathiwat, Southern Thailand, based on binomial distribution of Aedes vectors in water-holding containers (water storage containers, discarded receptacles, miscellaneous containers, and natural containers). The distribution of Aedes vectors was influenced seasonally by breeding outdoors rather than indoors in all 4 containers. Accordingly, both urban and rural settings elicited significantly seasonal (wet versus dry) distributions of Ae. aegypti larvae observed in water storage containers (P = 0.001 and P = 0.002) and natural containers (P = 0.016 and P = 0.015), whereas, in rural setting, the significant difference was observed in discarded receptacles (P = 0.028) and miscellaneous containers (P < 0.001). Seasonal distribution of Ae. albopictus larvae in any containers in urban setting was not remarkably noticed, whereas, in rural setting, the significant difference was observed in water storage containers (P = 0.007) and discarded receptacles (P < 0.001). Moreover, the distributions of percentages of container index for Aedes-infested households in dry season were significantly lower than that in other wet seasons, P = 0.034 for urban setting and P = 0.001 for rural setting. Findings suggest that seasonal and geographical variation of Aedes vectors affect the infestation in those containers in human inhabitations and surroundings. © 2016 Ornanong Boonklong and Adisak Bhumiratana.
Deeyai P.,King Mongkut's University of Technology Bangkok |
Amnuaycheewa P.,King Mongkut's University of Technology Bangkok |
Kerdtongmee P.,Nakhon Si Thammarat Rajabhat University
Key Engineering Materials | Year: 2016
Atmospheric pressure plasma is potential to inhibit microbial growth on various food surfaces without affecting product bulk and leave no significant chemical residues. The aim of this work was to study the effect of atmospheric pressure argon plasma on the mold growth on white flour wheat bread and whole wheat bread. Aspergillus sp., was isolated from the two breads and inoculated on potato dextrose agar (PDA) and was directly exposed to argon plasma jet treatment at powers of 10, 20, or 40W for 5 or 10 min. Fungal dry weight determination was used to study the effect of APJ on the inactivation of the molds on the breads. The results showed there is a correlation between power level and treatment time. The higher the power and the longer the treatment time, the higher the degree of fungal inactivation. The amounts of the molds were significantly reduced after plasma treatment, especially in power of 40 W for 10 min. These results demonstrated that argon plasma jet could be used effectively to inhibit the fungal growth on bread surface. © 2016 Trans Tech Publications, Switzerland.
Eadkhong T.,Walailak University |
Rajsadorn R.,Nakhon Si Thammarat Rajabhat University |
Jannual P.,Nakhon Si Thammarat Rajabhat University |
Danworaphong S.,Walailak University
European Journal of Physics | Year: 2012
We propose the use of Tracker, freeware for video analysis, to analyse the moment of inertia (I) of a cylindrical plate. Three experiments are performed to validate the proposed method. The first experiment is dedicated to find the linear coefficient of rotational friction (b) for our system. By omitting the effect of such friction, we derive I for a cylindrical plate rotated around its central axis from the other two experiments based on the relation between torque and angular acceleration of rotational motion and conservation of energy. Movies of the rotating plate and hung masses are recorded. As a result, we have the deviation of I from its theoretical value of 0.4% and 3.3%, respectively. Our setup is completely constructed from locally available inexpensive materials and the experimental results indicate that the system is highly reliable. This work should pave the way for those who prefer to build a similar setup from scratch at relatively low cost compared to commercial units. © 2012 IOP Publishing Ltd.
Chutinantakul A.,Nakhon Si Thammarat Rajabhat University |
Chutinantakul A.,Prince of Songkla University |
Tongkumchum P.,Prince of Songkla University |
Bundhamcharoen K.,International Health Policy Program IHPP |
Chongsuvivatwong V.,Prince of Songkla University
Population Health Metrics | Year: 2014
Background: It is known that death registry (DR) underestimates HIV deaths. The objectives of this study were to examine under-reporting/misclassification and to estimate HIV mortality in Thailand during 1996-2009 from a model based on 2005 verbal autopsy (VA) data.Methods: Logistic regression was used to predict HIV deaths from the VA dataset with and without demographic covariates. This full model was then used to predict individual HIV deaths from the DR dataset of provinces in which VA was conducted. The proportions in the remaining provinces were predicted from spatial interpolation based on coefficients of the VA provinces.Results: Area under Receiver Operating Characteristic curve of the full model was 0.969 compared to 0.879 of the simple cross-referencing model when demographic covariates were not included. DR-reported HIV deaths accounted for only one-third of all VA-estimated HIV deaths. The most misclassified HIV deaths were those registered as tuberculosis and mental and nervous system. Under-reporting was most common among females and people aged 20-39 years, and effect of province was highest in the upper north and upper south regions.Conclusions: For approximately two-thirds of all HIV deaths estimated by the full model, the causes were reported under other categories, not HIV. Demographic variables are essential for accurately correcting causes of death from death registries. © 2014 Chutinantakul et al.; licensee BioMed Central Ltd.