Somdock, Nuttakrit
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Item type:Publication, Enhanced thermoelectric properties of bismuth telluride via Ultra-Low thermal conductivity BOSC compound addition(2024-12-01); ; This study aimed to enhance the thermoelectric properties of bismuth telluride by adding Bi<inf>4</inf>O<inf>4</inf>SeCl<inf>2</inf> (BOSC). Commercial N-type bismuth telluride was mixed with BOSC powder in varying concentrations. As the BOSC content increased, the carrier concentration also rose due to chlorine atoms acting as donor impurities. Despite this increase, the power factor values of the samples with BOSC additives did not significantly differ from those of the bare bismuth telluride sample. However, the total thermal conductivity decreased significantly with the addition of BOSC, reaching a minimum value of 0.54 W·m<sup>–1</sup>·K<sup>–1</sup> at 150 °C for the sample with 1 wt% BOSC. Notably, the ZT value for the sample with 1 wt% BOSC was about 0.86, which is four times higher than that of the bare bismuth telluride sample. Our findings demonstrate superior thermoelectric performance, indicating a more efficient modification of thermoelectric properties through the addition of BOSC to the bismuth telluride matrix. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Modeling a Simple Single-phase Grid-connected Photovoltaic System Using Negative Conductance of Solar Cells(2023-01-01); ; ; Sirichote, WichitThis paper presents the simulation of a simple single-phase grid-connected photovoltaic (PV) system using the PSPICE model. The modeling system consists of a PV string, a single-phase current source inverter (CSI), load, and a grid voltage source. The system uses the PV string as the current source. The single-phase CSI was controlled by the grid AC voltage. The operation of the system employs the negative conductance characteristics of the PV string. We studied the voltage and current waveform at the inverter output terminal, the current waveform at the load, the AC power with various open-circuit voltages and temperatures of the PV string. The result showed the current waveform at the inverter output terminal follows the I-V characteristics of the PV string. The current waveform at the load depends on its impedance characteristics. The AC power increased with the open circuit voltage. We found that the maximum efficiency of the AC power conversion system was 63.3% at the peak of the AC voltage source, which was equal to the maximum power voltage of the PV string. In addition, the prototype was built for testing and testing verified the simulation results. The experimental results showed the current waveform at the inverter terminal and load were similar to the simulation results. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Engineering Education Roadmap of the Future Trend of Basic Metaverse based on VR with cooperation between the government and the private sector(2022-01-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Graphene addition improved figure of merit in SnTe prepared by the rapid hybrid microwave solid-state method(2022-02-01); ; ; We successfully synthesised SnTe-based powders (SnTe, Sn<inf>0.95</inf>Bi<inf>0.05</inf>Te, and SnTe with graphene addition) by a hybrid microwave solid-state method. This demonstrated comparable thermoelectric performance to the conventional heating method but had low energy consumption and rapid synthesis. Graphene addition to SnTe materials resulted in significant reduction of thermal conductivity. The SnTe with 5 wt% graphene exhibited a reduction in overall thermal conductivity from ∼10 W m<sup>−1</sup> K<sup>−1</sup> for SnTe to ∼2 W m<sup>−1</sup> K<sup>−1</sup> at 325 K and showed a moderate power factor. The Debye model was used to explain the origin of the effects of graphene on lattice thermal conductivity. The dimensionless figure of merit was increased by five times, from 0.07 for SnTe to 0.35 for SnTe with 5 wt% graphene. Our results demonstrated an effective method and additive material to synthesise and enhance the thermoelectric properties of SnTe materials. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis of Fe–Cu Alloys via Ball Milling for Electrode Fabrication Used in Electrochemical Nitrate Removal from Wastewater(2025-07-01); ; ; Srirach, PisanFe and Cu powders were mixed at a 50:50 ratio. Then, Fe-Cu alloys were prepared using the ball milling technique with different milling times of 6, 12, 18, 24, 30, 36, and 42 h. The crystalline structure was analyzed using X-ray diffraction (XRD), and it was found that the optimum milling time was 30 h. The homogeneity of the Fe and Cu elements in the Fe–Cu alloys was analyzed using the scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX) mapping technique. Additionally, the crystal orientation of the Fe–Cu alloys was investigated using transmission electron microscopy (TEM). To fabricate the cathode for nitrate removal via electrolysis, an Fe–Cu alloy milled for 30 h was deposited onto a copper substrate using mechanical milling, then annealed at 800 °C. A pulsed DC electrolysis method was developed to test the nitrate removal efficiency of the Fe–Cu-coated cathode. The anode used was an Al sheet. The synthesized wastewater was prepared from KNO<inf>3</inf>. Nitrate removal experiments from the synthesized wastewater were performed for durations of 0–4 h. The results show that the nitrate removal efficiency at 4 h was 96.90% compared to 74.40% with the Cu cathode. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Automated method for measuring the energy gap of p-n junction semiconductor diodes with the temperature-voltage method(2021-03-01); ; An automated system for measuring the energy gap E g of a p-n junction semiconductor diodes was presented in this study. The system, based on temperature-voltage (T-V) measurement, was designed and developed as a teaching tool to support teaching for undergraduate students. The energy gap of diodes was measured by varying the diode temperature from 273 to 343 K and by measuring the voltage drop across the diode while the bias current of diodes was kept constant at a specific value. In the proposed system, an Arduino UNO R3 microcontroller was employed to automatically acquire the temperature and voltage drop across the diode. T-V data were plotted, and then the slope and intercept were used to calculate the energy gap by a simplified diode equation. In this system, the temperature and voltage of the two diodes were measured simultaneously at different constant bias currents in the range of 10 μA-10 mA. The average E g value of 1.22 eV obtained in this work is in good agreement with that reported in the literature.2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhancement of thermoelectric properties in rapidly synthesised β-Cu2Se using optimized Cu content and microwave hybrid heating(2024-01-15); ; 3 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhanced thermoelectric properties of Cu2Se via Sb doping: An experimental and computational study(2023-02-01); ; 2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of real working environment/formation of oxide phase on thermoelectric properties of flexible Sb2Te3 films(2019-09-01); ; Flexible Sb<inf>2</inf>Te<inf>3</inf> thin films, for thermoelectric generator applications, were deposited by DC magnetron sputtering. As-deposited films were annealed in air to simulated a realistic operating environment. The oxidation behavior of the films was studied by monitoring their phase change on exposure to air at different temperatures between 50 and 300 °C for annealing times from 1 to 15 h. Oxidation of Sb and Te formed Sb<inf>2</inf>Te<inf>4</inf> and TeO<inf>2</inf> phases when annealing above 100 °C and Sb<inf>2</inf>Te<inf>3</inf> decomposed into oxide phases at an annealing temperature of 250 °C for 15 h. The thermoelectric performance decreased as the content of Sb<inf>2</inf>O<inf>4</inf> and TeO<inf>2</inf> phases increased. These findings show the limitations of Sb<inf>2</inf>Te<inf>3</inf> films operating in air without vacuum or a protective environment. We propose that the kinetic growth of oxide formation on the Sb<inf>2</inf>Te<inf>3</inf> thin films depend on chemical activation energy and oxygen diffusion through the oxide barrier by the variation of annealing temperature and annealing time, respectively.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhanced antimony telluride thermoelectric generators: From material synthesis to device applications(2025-12-01); ; This study investigates the effect of Bi₄O₄SeCl₂ (BOSC) addition (0–4 wt%) on the thermoelectric performance of p-type Bi₀.₅Sb₁.₅Te₃ synthesized via high-energy ball milling. XRD analysis revealed lattice incorporation at 1 wt% BOSC, while higher concentrations led to phase separation. The 1 wt% BOSC sample exhibited a significantly reduced total thermal conductivity of 0.28 W/m·K, compared to 0.46 W/m·K in the undoped sample, attributed to enhanced phonon scattering. Despite moderate decreases in electrical conductivity and Seebeck coefficient, a peak ZT of 1.02 at 50 °C was achieved—representing a ∼54 % improvement over the undoped material. Furthermore, a prototype thermoelectric module fabricated with BOSC-doped legs produced a power density of 17.6 mW/cm² under a 150 °C temperature gradient. These results demonstrate that BOSC is an effective additive for reducing thermal conductivity and enhancing overall thermoelectric performance, offering potential for energy harvesting applications at moderate temperatures.2