Chanthaburi, Thailand

Rambhai Barni Rajabhat University

www.rbru.ac.th
Chanthaburi, Thailand
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Leekul P.,Rambhai Barni Rajabhat University | Krairiksh M.,King Mongkut's University of Technology Thonburi
2016 IEEE Conference on Antenna Measurements and Applications, CAMA 2016 | Year: 2016

This paper presents simulation results that describes feature of a sensor system in a continuous process. The Rician k-factors from a single frequency-monostatic and a wideband-bistatic measurements can be used as indicators for classifying maturity stage of durian fruits. © 2016 IEEE.


Thassana C.,Rambhai Barni Rajabhat University | Thassana C.,National Astronomical Research Institute of Thailand Public Organization | Nuleg W.,Rambhai Barni Rajabhat University
AIP Conference Proceedings | Year: 2017

In this work, the effect of a carbon black (CB) on the thermal properties of briquettes produced from the charcoal and the salacca leafstalk with and without CB have been investigated. Four thermal properties of a briquettes compose of the burning time, the calorific value, the percentage moisture (PMC) and an percentage ash content (PAC) were analyzed using standard laboratory methods. Our results were indicated that the sallacca leafstalk mix a carbon black is the long burning times, high heating but a few ash content. Results shown that the burning time and the calorific value of a charcoal, a charcoal with CB, the salacca leafstalk and the salacca leafstalk with carbon black particles is about 58, 63, 76, 81 minutes, and 10.33, 12.96, 13.12, 14.63 MJ/kg, respectively. In addition, the PMC and PAC were in range of 11.6 - 8.14% and 9.33 - 5.42%. So, we can conclude that a cabon black affect on the thermal properties of a briquettes and salacca leaftstalk mixed CB has been most suited for briquetting. © 2017 Author(s).


Sakultanchareonchai S.,Bangkok University | Chairuangsri T.,Chiang Mai University | Imurai S.,Rambhai Barni Rajabhat University | Nisaratanaporn E.,Bangkok University
Materials Science Forum | Year: 2017

Microstructural and mechanical development of the various heat-treated 935 Ag-Cu alloys were explored. The heat-treatment processes were applied viz. holding before quenching for 2 and 15 min, homogenization at 750 °C for 60 min followed by water quenching, and aging at 350 °C for 15 to 60 min followed by water quench. It was found that the specimens with copper addition gave a high resiliency in all heat treatment conditions however the effect of homogenization with aging treatment fostered deep blemish or fire scale on its surface. The amplifications of resiliency of 935 heat-treated AgCuSn and AgCuBe alloy were increased but elongation values were slightly reduced. The 935 AgCuBeSn specimens produced adequate resiliency and elongation after aging at 350 °C for 15 to 60 min followed by water quenching. Partial dissolution and spheroidization of eutectic phase were occurred by homogenization treatment at 750 °C. Aging treatment promoted precipitation of 3-20 nm fcc (Cu,Sn)-rich precipitates and engendered an improvement of hardness, yield strength and the modulus of resilience or resiliency. © 2017 Trans Tech Publications, Switzerland.


Lertsakwimarn K.,Rambhai Barni Rajabhat University | Phongcharoenpanich C.,King Mongkut's University of Technology Thonburi | Fukusako T.,Kumamoto University
Call for Papers - ICCEM 2016: 2016 IEEE International Conference on Computational Electromagnetics | Year: 2016

A design of dual circularly polarized antenna is proposed. By two dual L-shaped probe structure, dual-sense circular polarization (CP) for radio astronomy is achieved. The dual L-shaped probes are place in the radial direction of a circular ring to obtain both right hand circular polarization (RHCP) and left hand circular polarization (LHCP). According to our simulation results, the proposed antenna element could achieve-10dB-level of S11 and more than-20dB-level of isolation in frequency range of 1.4-1.7 GHz. The antenna element broadside gain is approximately 8.5 dBic. The axial ratio (AR) below 3dB is more than 300 MHz in each circular polarization state. The details of simulation results for the proposed design are presented and discussed. © 2016 IEEE.


Matsutani M.,Yamaguchi University | Nishikura M.,Yamaguchi University | Saichana N.,Yamaguchi University | Saichana N.,Rambhai Barni Rajabhat University | And 5 more authors.
Journal of Biotechnology | Year: 2013

In vitro adaptation is one of the most challenging subjects in biology to understand adaptive evolution. Microbial adaptation to temperature is not only interesting in terms of understanding the adaptation mechanism, but also useful for industrial applications. In this study, we attempted the in vitro adaptation of Acetobacter pasteurianus SKU1108 by repeating its cultivation under high-temperature acetic acid fermentation conditions. As a result, thermo-adapted strains having the higher fermentation ability than the wild-type strain were obtained. Mutations and/or disruptions in several proteins of the adapted strains were detected with NGS sequencing technology. In particular, two different adapted strains had mutations or disruptions in three specific genes in common, suggesting that these genes are essential for thermotolerance or fermentation at higher temperature. In order to clarify their involvement in thermotolerance, two of the three genes were disrupted and their phenotype was examined. The results showed that mutations of the two proteins, MarR and an amino acid transporter, are partly responsible for higher fermentation ability and/or thermotolerance. Thus, it was suggested that these elevated abilities of the adapted strains are acquired by assembling several single gene mutations including the above two mutations. © 2013 Elsevier B.V.


Gorinstein S.,Hebrew University of Jerusalem | Poovarodom S.,King Mongkut's University of Technology Thonburi | Leontowicz H.,Warsaw University of Life Sciences | Leontowicz M.,Warsaw University of Life Sciences | And 6 more authors.
Food Research International | Year: 2011

The aim of this research was to investigate the bioactivity of durian, snake fruit and mangosteen, rare exotic Thai fruits. These fruits were compared among them and with conventional fruits: durian with mango and avocado, and snake fruit with mangosteen and kiwifruit in order to find the preferable diet for human consumption. The contents of polyphenols, flavonoids, flavanols, tannins, anthocyanins, ascorbic acid and carotenoids, and the level of antioxidant potential by ABTS, DPPH, FRAP and CUPRAC in different extracts (methanol, water, acetone, and hexane) were determined. The presence of polyphenols (flavonoids and phenolic acids) in the investigated samples was characterized by Fourier transform infrared (FT-IR) spectroscopy and three-dimensional fluorimetry (3D-FL).The in vivo studies were carried out on 25 male Wistar rats, divided into 5 diet groups, each of 5. During 30. days of the experiment the rats of all 5 groups were fed basal diet (BD), which included wheat starch, casein, soybean oil, vitamin and mineral mixtures. The rats of the Control group were fed only the BD. The BD of the other 4 groups was supplemented with 1% of nonoxidized cholesterol (NOC) (Chol group), 1% of NOC in each group and 5% of lyophilized fruits: durian (Chol/Durian), snake fruit (Chol/Snake), mangosteen (Chol/Mangosteen). After the experiment diets supplemented with exotic fruits significantly hindered the rise in plasma lipids and hindered the decrease in the plasma antioxidant activity. In conclusion, the contents of bioactive compounds and the antioxidant potential are relatively high in the studied fruits and varied among them depending on the extraction procedure. FT-IR and 3D-FL can be used as additional tools for identification and comparison of bioactive compounds. Supplementation of diets with exotic fruits positively affects plasma lipid profile and antioxidant activity in rats fed cholesterol-containing diets. © 2010 Elsevier Ltd.


Lertsakwimarn K.,Rambhai Barni Rajabhat University | Phongcharoenpanich C.,King Mongkut's University of Technology Thonburi
Lecture Notes in Electrical Engineering | Year: 2016

A low-profile ultrahigh frequency (UHF) passive radio frequency identification (RFID) tag for the applications to distinguish metallic from non-metallic is presented. The proposed antenna structure consists of T-shaped structure and parasitic parallel longitudinal strip lines which are placed symmetrically. There is an air gap between the head parts of T-shaped structure for installing IC chip. The head part has shorting pin that connects the ground plane. The parametric studies are described. From the results, the tag antenna with defected ground plane has larger difference of maximum read range compared between the tag on metallic plate and the tag in free space. The proposed UHF-RFID tag antenna can adjust the impedance characteristic by changing the length of the middle longitudinal strip. The tag antenna prototype is fabricated with an area of 90 × 20 × 3 mm3 (0.28λ0 × 0.06λ0 × 0.009λ0). The measured results of maximum read range on the metallic plate and in free space are 83 and 24 mm, respectively. The simulated and measured results of the proposed RFID tag antenna are discussed. © Springer International Publishing Switzerland 2016.


Potipat J.,Burapha UniversityChonburi | Potipat J.,Rambhai Barni Rajabhat University | Tangkrock-Olan N.,Burapha UniversityChonburi | Helander H.F.,Gothenburg University
EnvironmentAsia | Year: 2015

The sediment samples from 24 stations in coastal area of Chanthaburi Province were collected during March 2012 to March 2013 and analyzed for heavy metal contents (Pb,Cd, Ca, Fe, Cu and Zn), pH, onganic matters and grain sizes. The correlation analyses showed that heavy metal conceatrntions were affeeted by the content of organic matter and the size of clay particles. The evoluation of the quality of sediment was carried out using the geoaccumulation index (Igeo)and the enrichment factor (EF) as well at the comparison with those in t4e Thailand’s sediment quality guideiine (SQG) values. The results oe the geoaccumulation index and the enrichment factor values of the heavy metals content in the sediments revealed that the study area was unpolluted and not enriched, respectively. The relationship between the heavy metals concentration and the organic matter, and the clay particle wns proposed try using the multiple regression equations. © 2015 Thai Society of Higher Eduation Institutes on Environment


Sukhumpinij P.,Rambhai Barni Rajabhat University | Chanasit N.,Rambhai Barni Rajabhat University
Acta Horticulturae | Year: 2015

Efficient artificial seed protocol for the orchid Dendrobium friedericksianum Rchb.f. was developed for in vitro conservation study. Dendrobium friedericksianum Rchb.f. is a beautiful native Thai wild orchid found in the eastern provinces of Thailand especially in Chanthaburi province. Currently, illegal forest harvests are impacting this orchid. Meanwhile, environmental changes due to wood-cutting and the decreasing rate of natural breeding cause decreasing numbers of this orchid and lead to a higher risk of extinction. For the reasons mentioned, we have been trying to either keep or preserve the orchid strains. The present study was to develop an effective and applicable protocol for short term in vitro storage of protocorm-like bodies (PLBs) of this orchid species. PLBs were encapsulated in 3% sodium alginate (Na-alginate) and 100 mM calcium chloride (CaCl2.2H2O). The efficiency of survival declined with both increasing storage duration and storage temperature. The encapsulated PLBs were stored at 4 and 25°C for 30, 60, 90, 150 and 180 days. After storage, PLBs were transferred to modified VW medium to determine the time taken for germination, the germination percentage, and the morphological categorization of regenerated PLBs. Encapsulated PLBs stored at 4°C had rapid deterioration and complete death within 150 days, while those stored at 25°C were more tolerant to storage. Encapsulated PLBs survived longer when stored at 25°C compared to 4°C. All plantlets survived after acclimatization when transferred to greenhouse.


Moonrungsee N.,Rambhai Barni Rajabhat University | Pencharee S.,Ubon Ratchathani University | Jakmunee J.,Chiang Mai University
Talanta | Year: 2015

A field deployable colorimetric analyzer based on an "Android mobile phone" was developed for the determination of available phosphorus content in soil. An inexpensive mobile phone embedded with digital camera was used for taking photograph of the chemical solution under test. The method involved a reaction of the phosphorus (orthophosphate form), ammonium molybdate and potassium antimonyl tartrate to form phosphomolybdic acid which was reduced by ascorbic acid to produce the intense colored molybdenum blue. The software program was developed to use with the phone for recording and analyzing RGB color of the picture. A light tight box with LED light to control illumination was fabricated to improve precision and accuracy of the measurement. Under the optimum conditions, the calibration graph was created by measuring blue color intensity of a series of standard phosphorus solution (0.0-1.0 mg P L-1), then, the calibration equation obtained was retained by the program for the analysis of sample solution. The results obtained from the proposed method agreed well with the spectrophotometric method, with a detection limit of 0.01 mg P L-1 and a sample throughput about 40 h-1 was achieved. The developed system provided good accuracy (RE<5%) and precision (RSD<2%, intra- and inter-day), fast and cheap analysis, and especially convenient to use in crop field for soil analysis of phosphorus nutrient. © 2015 Elsevier B.V. All rights reserved.

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