Papers by Author: Atthakorn Thongtha

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Authors: Atthakorn Thongtha, Somchai Maneewan, Chantana Punlek, Yothin Ungkoon
Abstract: The effect of fine sand replacement by the sugar sediment (0, 10, 15, 20, 25, 30, 35, 40, 45 and 50 weight %) on the physical and mechanical properties was studied in this work. The physical and mechanical properties of AAC with various contents of sugar sediment were focused on the density, the humidity, the water absorption, the open porosity volume, the compressive strength and the flexural strength. The average density, humidity, water absorption, volume of open porosity, compressive strength and flexural strength of all compositions had the value in the range of 0.57-0.61 g/cm3, 23.0-26.7 %, 0.38-0.40 g/cm3, 259-287 cm3, 4.4-5.9 N/mm2 and 1.03-1.82 N/mm2, respectively. The maximum compressive strength and flexural strength were found from the AAC sample with the sugar sediment content of 30%, which were 5.9 N/mm2 and 18.14 N/mm2. Moreover, these samples also exhibited the density (0.60 g/cm3), the humidity (23.6%), the water absorption (0.39 g/cm3) and the volume of open porosity (272 cm3) were claimed in quality class of 4. The specimens of AAC with the sugar sediment content of 0-40% were claimed in quality class of 4, which based on the Thai Industrial Standard 1505-1998.
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Authors: Somchai Maneewan, Atthakorn Thongtha, Chantana Punlek
Abstract: This paper reports on experimental comparisons of coefficient of performance (COP) of a thermoelectric coolingsystem which cooled the hot side of the TEC by water (wc), ethylene glycol (egc) and nanofluids (nfc) The nanofluids is composed of ethylene glycol with silver nano(35 nm).The TEC was composed of the TE cooling modules, heat exchanger, and the air cooled heat sink at the cold side of the TE modules.Experiments were conducted with various current input 1 - 4.5 A to find out the optimum current input condition. To consideration of cooling capacity and COP of system was measured the hot and cold side temperature of TEC. Results shown that, the cooling capacity was increased with current input. The maximum cooling capacity of nfc, egc and wc are about 72, 62 and 41 W, respectively. Considered with highest COP found that the optimum current input is approximately 2.5 A. The maximum COP of nfc, egc and wc are about 2.01, 1.7 and 1.12, respectively. Therefore, the proposed TEC-nfc concept is expected to contribute to wider applications of the TE cooling system.
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Authors: Atthakorn Thongtha, Kritsana Angsukased, Theerachai Bongkarn
Abstract: The effect of calcination temperatures (1000-1400 oC) on the phase formation and microstructure of barium strontium zirconate titanate [(Ba0.25Sr0.75)(Zr0.75Ti0.25)O3 ; BSZT] powders were investigated. BSZT powders were prepared and compared by the solid state reaction method and the combustion technique. The higher calcination temperatures increased the percentage of the perovskite phase, but decreased the lattice parameter a. The same crystallographic pure perovskite phase of BSZT powders, which were prepared via the combustion technique were detected above 1300 oC ; which was lower than the calcinations temperature of mixed oxide method by 50 oC. The TGA-DTA results corresponded to XRD investigation. The microstructure of BSZT powders, which were prepared using both techniques, exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle sizes of BSZT powders prepared via the combustion technique (0.13-0.30 µm) and the solid state reaction method (0.18-0.38 µm) were increased with the increase of calcinations temperatures
197
Authors: Paisit Luangjok, Somchai Maneewan, Atthakorn Thongtha
Abstract: Effects of shading and blocking of solar radiation intensity through Fresnel lens onto solar cell were investigated in this work. Fresnel lens was made of polyvinyl chloride to concentrate the solar radiation onto the polycrystalline silicon solar cell with the 0.767 m x 0.670 m in size and no cooling under the solar panels. The temperature and efficiency comparisons between solar module with and without Fresnel lens were observed. The performance of the two modules overtime is assessed by monitoring the characteristic I-V and P-V curves. The maximum efficiency of the solar panels with Fresnel lens and without Fresnel lens in each hour was approximately 5-6.7% and 8.8-11.5%, respectively. This lower efficiency of PV module with Fresnel lens was a result of unsuitable distance of Fresnel lens that operated with the PV module.
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Authors: Atthakorn Thongtha, Theerachai Bongkarn
Abstract: Perovskite SrZrO3 ceramics were successfully prepared via a combustion technique. The effect of calcination temperatures (900-1400oC) and sintering temperatures (1400-1650oC) on phase and morphology evolution of perovskite SrZrO3 ceramics were studied. The highest purity of perovskite phase powder was obtained at 1250 oC and the purity of the perovskite phase of SrZrO3 ceramics were detected in the samples sintered at 1550 oC for 6 h. The SEM results showed the average particle size (84-214 nm) and the average grain size (0.35-2.09 µm) of samples increased with the increase of firing temperatures. The shrinkage of the ceramics increased as the sintering temperatures increased. The maximum density was ~98.4% of the theoretical density for the sample sintered at 1550 oC for 6 h.
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Authors: Somchai Maneewan, Weera Punin, Chantana Punlek, Atthakorn Thongtha, Tanongkiat Kiatsiriroat
Abstract: The main focus of this paper is concerned with the production and properties of refuse derived fuel 5 (RDF-5) for use in energy from waste technologies. The analysis was performed using feedstocks made up of residues from a range of mechanical biological treatment (MBT) plants and crude oil sludge. The RDF-5 was composed of crude oil sludge and mechanical biological waste treatment (MBWT). The ratios of MBWT to crude oil sludge were 5:95, 10:90, 15:85 and 20:80 respectively. The physical and thermal characteristics of RDF-5 were examined. This was further investigated in the context of the parameters required during production and the properties of RDF-5. RDF-5 was produced using a screw compactor. Analysis of the optimal mixing ratios between the crude oil sludge and MBWT were undertaken by testing the thermal value based on ASTM D 240 moisture contents was based on ASTM D 3173, ash was based on ASTM D 3174, and density was based on ASTM E 75 respectively. The results showed that the optimal ratios of MBWT to crude oil sludge were 15:85 and 20:80 have feasibility to produce the RDF-5. Because of the ratios of 15:85 and 20:80 have a high value 10,831 kcal/kg and 11,260 kcal/kg, the percentages of moisture were 2.73% and 5.93% and the density values were 750 kg/m3 and 806 kg/m3 respectively (RDF-5 has a high heating value (HHV > 5,000 kcal/kg), with the percentage of moisture content not exceeding 10 percent and the density value (D 600 kg/m3) according to production of solid fuels standards). The ash values were 5.10% and 4.74% respectively. Comparing the energy production costs between RDF-5 and other fuels used in Thailand we found that the production costs of RDF-5 were 0.014 /MJ and 0.013 /MJ which are comparable to that of paddy husk and much cheaper than those of fuel lignite and bituminous. This preliminary evaluation reveals that the recovery of energy through RDF-5 production from MBWT with crude oil sludge is cost attractive and it should be considered as a feasible option for utilizing energy from MBWT with crude oil sludge.
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Authors: Atthakorn Thongtha, Somchai Maneewan, Chantana Punlek, Yothin Ungkoon
Abstract: The comparison of microstructure and mechanical properties between the autoclaved aerated concrete (AAC) and the autoclaved aerated concrete consist of sugar sediment (AAC-SS) was investigated in this work. The microstructure of AAC and AAC-SS was analyzed by the scanning electron microscopy (SEM). The mechanical properties of AAC and AAC-SS were focused on the compressive strength, the density, the water absorption and the flexural strength. To comfirm the tobermorite phase, the phase formation of the samples was tested using X-ray diffraction (XRD). It was found that the microstructure of AAC and AAC-SS surface was the finer needle-like crystalline morphology. The compressive strength (5.9 N/mm2) and flexural strength (1.82 N/mm2) of AAC-SS were higher than that of the AAC (5.0 N/mm2 and 1.64 N/mm2). While, the value of density (0.60 g/cm3) and humidity (23.59%) of AAC-SS had little less than that of the AAC (0.61 g/cm3 and 24.11%). The increasing of the tobermorite phase, which was added by the sugar sediment, had affected to the improvement of the mechanical properties. The specimens of both AAC and AAC-SS were claimed in quality class of 4, which based on the Thai Industrial Standard 1505-1998.
1266
Authors: Atthakorn Thongtha, Hoy Yen Chan, Paisit Luangjok
Abstract: This study investigated the application of phase change material and fins into photovoltaic panel. The experimental design was divided into 2 cases: conventional photovoltaic and photovoltaic with phase change material and fins. The thermal performance and electrical efficiency was tested under the solar radiation simulator between 500 and 1000 W/m2. The insolation intensity was tested by an incident-light photometer. The power of the nine halogen lamps was controlled by a simple voltage control device. It was found that temperature of normal PV module is constant after the tested time of 20 minutes. The temperatures of PV module with phase change material and fins were lower than a normal PV module throughout the testing duration. Approximately 2-6% of photovoltaic module temperatures have decreased and this have improved the electrical efficiency of about 1-4%. This indicated the use of phase change material and fins is able to decrease the photovoltaic module temperature and thus increase the efficiency of photovoltaic module cooling.
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Authors: Atthakorn Thongtha, Surirat Ketchaona, Jutarud Wattana, Tanapon Patanin
Abstract: The research in this paper aims to study the physical, mechanical and thermal properties of building wall materials (Cellular lightweight concrete) with various proportions of Portland cement. The research in this paper is separated into two parts, in the first part, the density, water absorption and compressive strength of 7.0 cm x 7.0 cm x 7.0 cm concrete sample was investigated. This study found that the optimal proportion of Portland cement was 15% by weight (this condition showed the highest compressive strength of 3.62 MPa). The physical and mechanical properties of lightweight concrete conformed to the Thai Industrial Standard 2601-2013. In the second step, the thermal properties of the improved lightweight concrete, brick and commercial concrete were compared. It was found that the samples with increasing 15% by weight of Portland cement showed the lowest heat flux that affected to a lower tested room temperature as well.
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Authors: Atthakorn Thongtha, Kritsana Angsukased, Theerachai Bongkarn
Abstract: The effect of calcination (1000-1400 oC) and sintering temperatures (1400-1600 oC) on the phase formation and microstructure of barium strontium zirconate titanate [(Ba0.25Sr0.75)(Zr0.75Ti0.25)O3; BSZT] ceramics were investigated. BSZT powders were prepared by the solid-state reaction method. Higher calcination temperatures increased the percentage of the perovskite phase, but decreased the lattice parameter a of BSZT powders. The pure perovskite phase of BSZT powders was detected above the calcination temperature of 1350 oC. The microstructure of BSZT powders exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle size and the average grain size of the ceramics were increased with the increase of calcination and sintering temperatures. The highest density of the samples was 5.42 g/cm3 which was obtained from ceramic sintered at 1550 oC for 2 h.
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