Lekchaum, Sarai
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Lekchaum, Sarai
Alternative Name
Lekchaum, S.
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Email
sarai.le@kmitl.ac.th
10 results
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Item type:Publication, Modeling and Numerical Simulation for a Spherical Vector-Potential Coil(2020-06-01); Daibo, MasahiroWe proposed a model for a spherical vector-potential coil and investigated the properties of the coil, including the uniform distribution of the vector potential. We modeled a structure in which thin toroidal coils are superposed along a spherical surface. Rather than arranging the toroidal coils in close contact with each other along the surface of the sphere, the layer spacing of the toroidal coils should be constant so that the projection onto the axis of the sphere is equally spaced. When a current was applied to a toroidal coil, no magnetic field was created outside the toroidal coils; instead, a vector potential was present. When the same current was passed through each toroidal coil, the vector potential in the sphere achieved a uniform distribution by superposition. We presented the results of our numerical simulation of the distribution of the vector potential and the induced voltage when a secondary conductor was passed through the coil. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Calculation of Lead-Iron Double-Layer Thickness for Gamma-Ray Shielding by MATLAB Program(2017-01-01); This contribution is aimed at designing the optimal thickness of lead-iron double-layer container to store a radioactive waste releasing the photon energy at 1.3325 MeV and initial radiation intensity at 100 mSv/hr using the optimization design by MATLAB software. This design consisted of three parts of calculations to achieve 1000 times the radiation attenuation of container. The first was the logarithmic interpolation for the mass attenuation coefficient. The second was the bilogarithmic interpolation for the exposure buildup factor. The third was the contour-plotting analytical technique for the optimal thickness of radiation container. The values of mass attenuation coefficient and exposure buildup factor were exactly validated as compared with the standard reference database. Furthermore, we have found that the optimal thickness was 3.2 cm for lead (1st layer) and 17.0 cm for iron (2nd layer). Container weight was 994.30 kg, whilst container cost was 167.30 USD. The benefit of our design can quickly and precisely apply for the radiation safety assessment of the occupational radiation workers who always work in the nuclear reactor area. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Design of dual flywheels with connecting rods for gamma-type Stirling engine(2018-01-01); A gamma-type Stirling engine, based on a dual flywheels’ concept, was designed and fabricated. Optimized design of the engine, with connecting rods, was introduced to achieve a steady state of the Stirling engine cycle. Performances of the engine were therefore presented in terms of piston motion, inertia force, angular speed, pressure-volume diagram and temperature difference. It was found that optimum length of 45 mm from the connecting rod was able to reach the maximum output mechanical speed of 738 rpm at the maximum inertia force of 0.5 N. The engine offered thermal efficiency of 46.15% and total output power of 1.21 W under the temperature difference of 267 K. In the future, this design is expected to prove useful for applications in portable generators. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Analysis of neutron flux measurement in Thai Research Reactor-1/Modification 1 using the Monte Carlo method(2014-01-01); Tippayakul, C.This study adopts the Monte Carlo method to analyze the neutron flux measurement technique in Thai Research Reactor-1/Modification 1(TRR-1/M1) by performing simulations using MCNPX computer program. The neutron flux measurement technique being analyzed is called "gold foil activation technique". The simulation model consists of gold foil located in the middle of in-core irradiation which is in the center of the reactor core. The variation in the calculated neutron flux is assessed by varying the gold foil thickness from approximately 500 - 800 μcm. It is found from the simulation that the calculated neutron flux can differ by 33% when increasing the gold foil thickness by 60%. In addition, more detailed simulations to determine neutron flux distribution within the gold foil are performed to study and explain the variation in neutron flux calculated at different foil thicknesses. The simulation result shows that self-shielding effect has significant impact to the neutron flux distribution within the gold foil, and hence to the average neutron flux. © (2014) Trans Tech Publications, Switzerland. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Water remediation with a dielectric-free portable triple-electrode cold plasma discharge system(2024-01-01); This paper presents the design and application of a portable multi-electrode cold plasma corona discharge system for pollutant degradation in wastewater. The system generated stable plasma without a dielectric barrier, producing active species such as hydroxyl radicals, hydrogen peroxide, nitrite, and nitrate. The experimental results presented a pollutant degradation efficiency of 100%, reducing methylene blue as a model pollutant from 6 ppm to 0 ppm within 125 s at an optimized electrode distance of 0.20 cm. This optimization minimizes the risks associated with the arcing and self-collision of plasma streams while sustaining continuous plasma discharge, ensuring the maximum breakdown voltage and high ion density for efficient plasma production. The system further demonstrated its application in treating hand washing as a target pollutant to reduce the risk of infection during the COVID-19 pandemic. A comparative analysis highlighted the advantages of the system in terms of rapid treatment, energy efficiency, and low-cost operation. The processed water met the World Health Organization (WHO) wastewater discharge standards and WHO guidelines for virus elimination, with residual nitrogen compounds maintained below 50 ppm and hydrogen peroxide levels kept under 5,000 ppm, confirming the effectiveness of the system in pathogen reduction and wastewater purification. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preliminary validation of computational model for neutron flux prediction of Thai Research Reactor (TRR-1/M1)(2015-05-07); Tipayakul, C.This study is a part of an on-going work to develop a computational model of Thai Research Reactor (TRR-1/M1) which is capable of accurately predicting the neutron flux level and spectrum. The computational model was created by MCNPX program and the CT (Central Thimble) in-core irradiation facility was selected as the location for validation. The comparison was performed with the typical flux measurement method routinely practiced at TRR-1/M1, that is, the foil activation technique. In this technique, gold foil is irradiated for a certain period of time and the activity of the irradiated target is measured to derive the thermal neutron flux. Additionally, the flux measurement with SPND (self-powered neutron detector) was also performed for comparison. The thermal neutron flux from the MCNPX simulation was found to be 1.79×10<sup>13</sup> neutron/cm<sup>2</sup>s while that from the foil activation measurement was 4.68×10<sup>13</sup> neutron/cm<sup>2</sup>s. On the other hand, the thermal neutron flux from the measurement using SPND was 2.47×10<sup>13</sup> neutron/cm<sup>2</sup>s. An assessment of the differences among the three methods was done. The difference of the MCNPX with the foil activation technique was found to be 67.8% and the difference of the MCNPX with the SPND was found to be 27.8%. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Improvement of thermal performance of gamma-type stirling engine(2018-06-04); The gamma-type stirling engine was designed and fabricated using three main types of the materials for the engine assembly in order to get better the heat transfer between the cold and hot sides of the engine cylinders. Stainless steel and brass were applied for the hot cylinder, whereas aluminum was used for the cold cylinder. We have achieved the indicated work, engine speed and indicated power of 71.64 mJ, 599 rpm and 0.71 J/s, respectively. Furthermore, we were able to accomplish the constant temperature difference of 300 K with the thermal efficiency of 40 %. The improvement of the engine performance was confirmed by the heat flow simulation via the Solidwork program. Our inexpensive home-made engine is expected to be very useful for the people in the rural areas where the electricity is unable to reach them. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, In-house development of neutron moisture gauge for field measurement(2017-10-20); Kanjana, K.The measurement of moisture content in soil is based on the principle of neutron back scattering. In this principle, when fast neutrons emitted from a radioactive source collide with hydrogen atoms their energies are much greater reduced than colliding with other elements. The number of slowed down neutrons, hence, represents the number of hydrogen atoms present in the vicinity of the source. As water is the main contributor of hydrogen atoms in a soil medium, the moisture content in soil, therefore, can be measured based on this principle. An in-house developed probe containing a source of fast neutrons and a slow neutron detector was inserted into soil at different depths under the ground level. The probe was made of high density polyethylene and connected to a suitably calibrated detection system by a single cable. The moisture content was determined from the slow neutron count rate. The results of field measurement tests were reported and discussed. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Home-made temperature monitoring system from four-channel K-type thermocouples via internet of thing technology platform(2018-06-04) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Continuous spectrum generated by the excited dental X-ray tube(2010-10-01); Yupapin, P. P.The continuous X-ray spectral profiles have been successfully produced using the excited dental X-ray tube, where used dental X-ray tube was employed in the experimental setup. The effect of parameters on the continuous spectrum is investigated, whereas the major parameters are the anode current and adjustable voltage. It was found that the optimum conditions for the threshold voltage were three times higher than the highest energy absorption edge with tungsten anode target on the spectral distribution of radiation energy, which was increased, and the short wavelengths limitation obtained are 1.03, 0.73, 0.59, 0.48 and 0.46 . The relative sensitivity is increased from 12 to 25 kV, and it is decreased at 26 and 27 kV. The intensity near the short wavelength is increased by the double voltage value. © 2009 Elsevier GmbH.