Limchoowong N.,Materials Chemistry Research Center |
Sricharoen P.,Materials Chemistry Research Center |
Techawongstien S.,Khon Kaen University |
Kongsric S.,Materials Chemistry Research Center |
Chanthai S.,Thailand Institute of Nuclear Technology
Journal of the Brazilian Chemical Society | Year: 2017
In this study, we report a new method for iodine extraction from table salts, vegetables, and other food products using ultrasound-Assisted extraction, prior to the iodine determination by inductively coupled plasma optical emission spectrometry. For the ultrasound-Assisted extraction, deionized water as the extraction solvent and an extraction time of 5 min were found to be the most optimum condition. A linear calibration curve was plotted for 0.1 to 200.0 mg L-1 iodine convention. The limits of detection and quantification were 0.049 and 0.164 mg L-1, respectively. The precision for intra-And inter-day analyses was 2.75 and 4.54%, respectively. The accuracy of the method was confirmed with certified reference materials. Recoveries in 47 real samples were ranged between 80.48 and 118.1%. Therefore, the proposed method could be considered as a rapid, simple, and environmental-friendly method (the green extraction) to determine the trace amounts of iodine in different kinds of food products. © 2017 Sociedade Brasileira de Química.
Chankow N.,Bangkok University |
Punnachaiya S.,Bangkok University |
Wonglee S.,Thailand Institute of Nuclear Technology
Applied Radiation and Isotopes | Year: 2010
The aims of this research are to study properties of a neutron imaging plate (NIP) and to test it for use in nondestructive testing (NDT) of materials. The experiments were carried out by using a BAS-ND 2040 Fuji NIP and a neutron beam from the Thai Research Reactor TRR-1/M1. The neutron intensity and Cd ratio at the specimen position were approximately 9×105 ns/cm2 s and 100 respectively. It was found that the photostimulated luminescence (PSL) readout of the imaging plate was directly proportional to the exposure time and approximately 40 times faster than the conventional NR using Gd converter screen/X-ray film technique. The sensitivities of the imaging plate to slow neutron and to Ir-192 gamma-rays were found to be approximately 4.2×10-3 PSL/mm2 per neutron and 6.7×10-5 PSL/mm2 per gamma-ray photon respectively. Finally, some specimens containing light elements were selected to be radiographed with neutrons using the NIP and the Gd converter screen/X-ray film technique. The image quality obtained from the two recording media was found to be comparable. Crown Copyright © 2009.
Rattanaphra D.,Thailand Institute of Nuclear Technology |
Rattanaphra D.,Kasetsart University |
Harvey A.P.,Northumbria University |
Thanapimmetha A.,Kasetsart University |
Srinophakun P.,Kasetsart University
Fuel | Year: 2012
Simultaneous catalysed transesterification of rapeseed oil and esterification of 10 wt% myristic acid with methanol was studied using sulphated zirconia and in the absence of catalyst. The maximum total FAME content of 86% was obtained at a catalyst loading of 3 wt%, temperature of 170°C, pressure of 22 bars, molar ratio of oil to methanol of 1:20 and stirring rate of 600 rpm for 60 min. At these conditions, FFA was observed to reach 2.95% (2.94 mg/ml sol.). Thermo/catalytic cracking and hydrolysis of triglyceride was presumed to form the FFA. Water was also formed: dehydration of methanol is likely to be the principal source. Three sets of main reactions occurred at distinctly different rates. Esterification of myristic acid was the most rapid reaction. Direct transesterification of triglyceride and side-reactions of thermo/catalytic cracking of triglyceride followed by esterification of fatty acid and hydrolysis of triglyceride followed by esterification of fatty acid occurred afterward. Dehydration of methanol was observed throughout the reaction, producing a constant supply of water, thereby facilitating hydrolysis reactions. © 2012 Elsevier Ltd. All rights reserved.
Jannoo K.,Kasetsart University |
Teerapatsakul C.,Kasetsart University |
Punyanut A.,Thailand Institute of Nuclear Technology |
Pasanphan W.,Kasetsart University
Radiation Physics and Chemistry | Year: 2015
Silver nanoparticles (AgNPs) in chitosan (CS) stabilizer were successfully synthesized using electron beam irradiation. The effects of irradiation dose, molecular weight (MW) of CS stabilizer, concentration of AgNO3 precursor and addition of tert-butanol on AgNPs production were studied. The stability of the AgNPs under different temperatures and storage times were also investigated. The AgNPs formation in CS was observed using UV-vis, FT-IR and XRD. The characteristic surface plasmon resonance (SPR) of the obtained AgNPs was around 418nm. The CS stabilizer and its MW, AgNO3 precursor and irradiation doses are important parameters for the synthesis of AgNPs. The optimum addition of 20% v/v tert-butanol could assist the formation of AgNPs. The AgNPs in CS stabilizer were stable over a period of one year when the samples were kept at 5°C. The AgNPs observed from TEM images were spherical with an average particle size in the range of 5-20nm depending on the irradiation doses. The AgNPs in CS solution effectively inhibited the growth of several fungi, i.e., Curvularia lunata, Trichoderma sp., Penicillium sp. and Aspergillus niger, which commonly found on the building surface. © 2015 Elsevier Ltd.
Wimolwattanapun W.,Thailand Institute of Nuclear Technology |
Hopke P.K.,Clarkson University |
Pongkiatkul P.,King Mongkut's University of Technology Thonburi
Atmospheric Pollution Research | Year: 2011
Fine and coarse fractions of PM10 (PM2.5 and PM2.5-10, respectively) were collected from January 2003 to December 2007 at an urban Bangkok site (Chatuchak district) and a suburban site (Klongha district, Pathumthani) in Thailand. The filter samples were analyzed for mass, black carbon, and up to 28 elements were determined using instrumental neutron activation analysis and Particle-Induced X-ray Emission (PIXE). The long-term database shows that PM mass at the urban area had higher mass, black carbon, and some elements than the one at the suburban area. Furthermore, it is found that mass and elemental concentrations were generally elevated in the coarse fractions whereas black carbon was the major content in fine fractions. Positive Matrix Factorization (PMF) and multiple linear regression were applied to investigate for PM source fingerprints and apportionment. Source contributions and wind direction influence were also examined by use of conditional probability function (CPF) and potential source contribution function (PSCF). The PMF results indicated that major sources contributed to coarse fractions were soil, construction, whereas traffic and biomass burning were the major sources for fine fractions. CPF and PSCF models assisted in determining of the potential locations and/or the preferred pathways of these possible sources. © Author(s) 2011.
Silva K.,Thailand Institute of Nuclear Technology |
Ishiwatari Y.,University of Tokyo |
Takahara S.,Japan Atomic Energy Agency
Reliability Engineering and System Safety | Year: 2014
The Fukushima Accident emphasizes the need to integrate the assessments of health effects, economic impacts, social impacts and environmental impacts, in order to perform a comprehensive consequence assessment of severe accidents in nuclear power plants. "Cost per severe accident" is introduced as an index for that purpose. The calculation methodology, including the consequence analysis using level 3 probabilistic risk assessment code OSCAAR and the calculation method of the cost per severe accident, is proposed. This methodology was applied to a virtual 1,100 MWe boiling water reactor. The breakdown of the cost per severe accident was provided. The radiation effect cost, the relocation cost and the decontamination cost were the three largest components. Sensitivity analyses were carried out, and parameters sensitive to cost per severe accident were specified. The cost per severe accident was compared with the amount of source terms, to demonstrate the performance of the cost per severe accident as an index to evaluate severe accident consequences. The ways to use the cost per severe accident for optimization of radiation protection countermeasures and for estimation of the effects of accident management strategies are discussed as its applications. © 2013 Elsevier Ltd. All rights reserved.
Chittasupho C.,Srinakharinwirot University |
Lirdprapamongkol K.,Chulabhorn Research Institute |
Kewsuwan P.,Thailand Institute of Nuclear Technology |
Sarisuta N.,Thammasat University
European Journal of Pharmaceutics and Biopharmaceutics | Year: 2014
Doxorubicin is used to treat a variety of cancers, but dose limiting toxicity or intrinsic and acquired resistance limits its application in many types of cancer. CXCR4 is a chemokine receptor which implicates in metastasis of cancers including lung cancer. LFC131, a peptide inhibitor of CXCR4-ligand binding, is a linear type of low molecular weight CXCR4 antagonist. In this study, we investigated the possibility of using LFC131 conjugated nanoparticles for targeted delivering doxorubicin to CXCR4 expressing lung cancer cells. The LFC131 peptide was conjugated to sodium carboxylmethyl cellulose coated poly(dl-lactic-co-glycolic acid) (PLGA) nanoparticles. Binding and cellular uptake of doxorubicin-loaded LFC131 conjugated nanoparticles (LFC131-DOX NP) in adenocarcinomic human alveolar basal epithelial cells called A549 cells were higher and faster than that of untargeted nanoparticles. The specificity of CXCR4-mediated internalization of LFC131-DOX NPs was confirmed by using free LFC131 peptide or anti-CXCR4 monoclonal antibody. Cell studies suggested that sustained release of doxorubicin afforded by PLGA nanoparticles may enable LFC131-DOX NP as a targeted and controlled release drug delivery system. © 2014 Elsevier B.V. All rights reserved.
Wetchagarun S.,University of Washington |
Wetchagarun S.,Thailand Institute of Nuclear Technology |
Riley J.J.,University of Washington
Physics of Fluids | Year: 2010
The dispersion and temperature distribution of inertial particles are important in many turbulent, multiphase flow problems. In order to understand these better, direct numerical simulations (DNSs) are performed for inertial particles in a fluid with a constant temperature gradient and whose motion is either statistically stationary or decaying, isotropic turbulence. It is found that, for long times, the dispersion of inertial particles is the greatest when the Stokes number, Stη=τp/τη, is of order 1, where τp and τη are, respectively, the particle response time and the flow Kolmogorov time scale. A similar result is found for the long time behavior of the time rate of change of the mean-square particle temperature fluctuations, d
Hemvichian K.,Thailand Institute of Nuclear Technology |
Chanthawong A.,Thailand Institute of Nuclear Technology |
Suwanmala P.,Thailand Institute of Nuclear Technology
Radiation Physics and Chemistry | Year: 2014
Superabsorbent polymer (SAP) was synthesized by radiation-induced grafting of acrylamide (AM) onto carboxymethyl cellulose (CMC) in the presence of a crosslinking agent, N,N'-methylenebisacrylamide (MBA). The effects of various parameters, such as dose, the amount of CMC, AM, MBA and ionic strength on the swelling ratio were investigated. In order to evaluate its controlled release potential, SAP was loaded with potassium nitrate (KNO3) as an agrochemical model and its potential for controlled release of KNO3 was studied. The amount of released KNO3 was analyzed by an inductively coupled plasma mass spectrometry (ICP-MS). The results from controlled release experiment agreed very well with the results from swelling experiment. The synthesized SAP was characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The obtained SAP exhibited a swelling ratio of 190g/g of dry gel. © 2014.
Kewsuwan P.,Thailand Institute of Nuclear Technology |
Chukaew S.,Thailand Institute of Nuclear Technology
Energy Procedia | Year: 2016
The present study reports the effect of different molecular weight and concentration of irradiated chitosan on preliminary plant growth promoter test of corn in potting experiment. The average molecular weights of degraded chitosan were determined by intrinsic viscometric and GPC analysis. Four kinds of ultrafiltration membrane were used to separate the 100 kGy irradiated chitosan into five fractions (<10, 10-30, 30-50, 100-300, and >300 kDa). All five separated fractions, the irradiated and unirradiated chitosan were used for plant growth test of corn. The effects of different molecular weight fractions and concentrations of chitosan on average plant height, leaf greenness, average ear number and average ear weight of corn were studied. The results show that irradiated and unirradiated chitosan at concentrations ranging from 20, 50 and 100 ppm are effective for the growth promotion of corn plant, such as plant height, number of ear and ear size, in comparison with the control (untreated chitosan). © 2016 The Authors.