Somdock, Nuttakrit
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Item type:Publication, Advanced AlN/SiO2/AlN multilayer coatings for protecting gold-like decorative surfaces: Improved hardness and color stability(2025-12-01); ; This study explores the development of multilayer AlN/SiO<inf>2</inf>/AlN thin film coatings to enhance tarnish resistance, surface hardness, and color stability of gold-coated silver substrates for decorative use. Gold films were deposited via electroplating, followed by multilayer coatings using reactive magnetron sputtering. The SiO<inf>2</inf> thickness was systematically varied while maintaining fixed AlN layers. Optical evaluations using CIE Lab parameters confirmed that the specimen with a 110-min SiO<inf>2</inf> layer exhibited acceptable color difference (ΔE < 5). X-ray photoelectron spectroscopy (XPS) revealed stable Al–N and Si–O bonds with minimal oxidation. Nanoindentation tests showed a significant hardness increase, reaching 7.02 ± 0.62 GPa. After 240 days of ambient exposure, multilayer-coated samples showed no visible discoloration or sulfur-induced degradation, unlike uncoated and electrochemically coated samples. These results confirm that AlN/SiO<inf>2</inf>/AlN multilayers effectively improve the durability and aesthetic stability of gold-like surfaces, offering a promising solution for long-term decorative applications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Nitrate Removal Enhancement Using Pulse Electrolysis and Aluminum Electrode(2025-01-01); ; ; Srirach, PisanThis work focuses on nitrate elimination from municipal wastewater by an electrochemical method with pulsed DC electrolysis. The performance of electroreduction of nitrate was investigated without alkaline electrolyte addition. The nitrate removal reactor was fabricated from acrylic and aluminum electrodes. The nitrate concentration was analyzed by the light absorption of the substance using UV-Vis spectroscopy. The precipitated compounds were determined by X-ray diffraction technique. The experimental results with 180 min treatment indicated the optimum condition for nitrate removal, which was carried out on the pulse frequency of 10 kHz, pulse width of 80%, and electric current density of 16 mA/cm<sup>2</sup>. This condition was able to eradicate nitrate up to 90.73% (4.3 mg/L) from an initial nitrate concentration of 46.0 mg/L with a nitrogen selectivity of 80.08%. Furthermore, the weight loss of aluminum anodes was as low as 0.8%. The main precipitation formed in the electrolyte cell was aluminum hydroxide. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effects of Red and Blue LEDs Light on Growth and Development of Chrysanthemum Callus(2025-07-01); ; Effects of LED illumination on callus induction from petals of Karaked and Scarlet chrysanthemums cultivated in MS medium supplemented with 2 mg/I NAA and 4 mg/l Kinetin, under white LED light (PPFD 30±2 µmol/m2/s) and red to blue light in the ratios 30:10, 40:15, and 30:3 (PPFD 50±2 µmol/m2/s) for 16 h. It was determined that a light ratio throughout 4 weeks culture period had no impact on the fresh weight of callus. Conversely, varying light proportions yield distinct callus dry weights. Upon evaluating cultivar parameters, it was determined that ‘Karaked’ exhibited more fresh and dry weight compared to the callus of the ‘Scarlet’. Analysis of Karaked’s callus showed that callus cultured under 30:3 red to blue LED light exhibited the largest concentrations of all photosynthetic pigments, the greatest levels of malondialdehyde (MDA) and total phenolic compounds, and the lowest EC<inf>50</inf> value for DPPH free radical inhibition. In the case of the Scarlet chrysanthemum, following 8 weeks of callus induction, it was observed that a light ratio of red to blue at 40:15 yielded the maximum concentrations of chlorophyll a and carotenoids. No statistical difference was seen in the quantity of chlorophyll b. The MDA content of Scarlet’s callus cultivated under white LED light was the highest, and the EC<inf>50</inf> value for DPPH free radical inhibition was also the highest. Callus produced under red to blue LED light ratios of 30:10, 40:15, and 30:3 exhibited greater quantities of phenolic compared to callus cultured under white LED light. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Simultaneous Seebeck coefficient and electrical conductivity enhancement of GeSbTe films via Sn addition(2022-06-15); ; Sn-added GeSbTe (GST) thin films were deposited using a co-magnetron sputtering technique. The effects of varying the Sn content through a variable Sn target sputtering power and post annealing at 673 K were investigated. The DC power density applied to the GST target was controlled at 50 W, while the power density of the Sn target was increased from 0 W to 40 W. The results demonstrate the coexistence of the fcc-GST, hcp-GST and SnTe phases in the Sn-added GST thin films. The substitution of Sn at the Ge-site increases the crystallization speed and leads to defects and lattice disordered local arrangement in the GST films, causing the Seebeck coefficient to increase. The SnTe phase was created as a result of the high Sn content in the sample due to the over-doping limit of Sn into the GST structure. The presence of SnTe in Sn-doped GST films increased the electrical conductivity. The maximum power factor of 17.0 μW/cmK<sup>2</sup> at 450 K was obtained at an Sn content of 14.7 at%. These results indicated that the thermoelectric properties of Sn-doped GST films were improved via the formation of an appropriate amount of SnTe composite. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Triboelectric Nanogenerator Prepared from Poly(vinylidene Fluoride-Hexafluoropropylene) Polymer Composite(2023-01-01); ; In this work, poly(vinylidene fluoride-hexafluoropropylene)/reduced graphene oxide films were prepared by the solution casting method with N,N-dimethylformamide (DMF) and DMF/acetone mixed solvents. The effects of reduced graphene oxide and solvent type on the morphology and crystal structure of the composite films were investigated by using scanning electron microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy, respectively. The morphology study showed that the addition of acetone in the film process resulted in the occurrence of tiny pores on the film surfaces. The reduced graphene oxide incorporated into the PVDF-HFP was able to promote the formation of β- phase in the composites. The maximum power of 15.58 µW was obtained from the films using DMF/acetone mixture as solvent. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Sputter-deposited AlN coatings for enhanced tarnish resistance and mechanical durability of silver jewelry(2026-04-01); ; ; Silver jewelry is prone to surface tarnishing caused by sulfur-containing species in ambient environments. In this study, a transparent aluminum nitride–based thin film was deposited by magnetron sputtering and evaluated as a protective barrier against silver tarnishing. Sheets of 99.9% pure silver were coated under various nitrogen flow conditions to optimize film composition and performance. An appropriate nitrogen flow rate of 25 standard cubic centimeters per minute (sccm), corresponding to an N₂/Ar gas ratio of approximately 1:1, was identified for forming AlN-rich films, while an AlN-based film thickness in the range of 80–110 nm was found to be suitable for jewelry protection. X-ray photoelectron spectroscopy analysis showed that insufficient nitrogen availability suppresses complete nitridation, resulting in residual metallic aluminum, which readily reacts with residual oxygen and moisture, increasing the oxygen content in the films. At an N₂ flow rate of 25 sccm, metallic aluminum was suppressed and the films were dominated by Al–N bonding with minor oxygen incorporation, accompanied by the development of a polycrystalline structure. Nanoindentation measurements performed on the 110 nm-thick film yielded a peak hardness of approximately 3.6 GPa, indicating enhanced mechanical durability compared with uncoated silver. Comparative evaluation of color difference, mechanical hardness, tarnish resistance, and environmental durability demonstrated improved performance of the AlN-coated silver. Finally, the practical applicability of the coating was demonstrated by depositing AlN-based films onto large and intricately designed silver jewelry items, indicating compatibility with industrial-scale processing. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Contact Angle Measurement of Melting SnAgCu Solder Paste Mix with Carbon Allotropes Using In-Line Digital Holography Technique(2021-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Personal Identification using the Distance and Triangle between the Metacarpophalangeal Joints(2022-01-01); ; Sawangjit, NalitaPersonal identification using the distance among the metacarpophalangeal joints (MCPs) was presented in this study. The system was developed to specify the dorsal hand patterns. Firstly, the dorsal hand images were taken for the subjects via an infrared camera. Secondly, the dorsal hand images were converted to grayscale and binary images using image processing techniques. After that, the distance of the MCPs was measured by various the dorsal hand images including index to middle, middle to ring, ring to little, and index to little of the dorsal hand. In addition, the triangle areas between index to middle, middle to ring, ring to little, and index to little of the dorsal hand were used to specify the dorsal hand patterns. The result of the distance and the triangle area of the MCPS can be used to identify a person because of the difference of distance and the triangle area of the MCPs of each person. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Optimizing Waste Heat Conversion: Integrating Phase-Change Material Heatsinks and Wind Speed Dynamics to Enhance Flexible Thermoelectric Generator Efficiency(2024-01-01); ; ; Flexible thermoelectric generators (FTEGs) have garnered significant attention for their potential in harnessing waste heat energy from various sources. To optimize their efficiency, FTEGs require efficient and adaptable heatsinks. In this study, we propose a cost-effective solution by integrating phase-change materials into FTEG heatsinks. We developed and tested three flexible phase-change material thicknesses (4 mm, 7 mm, and 10 mm), focusing on preventing leaks during operation. Additionally, we investigated the impact of wind speed on the output performance of FTEGs with a flexible phase-change material heatsink. The results indicate that the appropriate flexible phase-change material thickness, when integrated with considerations for wind speed, demonstrates remarkable heat-absorbing capabilities at phase-change temperatures. This integration enables substantial temperature differentials across the FTEG modules. Specifically, the FTEG equipped with a 10 mm thick flexible phase-change material heatsink achieved a power density more than four times higher when the wind speed was at 1 m/s compared to no wind speed. This outcome suggests that integrating phase-change material heatsinks with relatively low wind speeds can significantly enhance flexible thermoelectric generator efficiency. Finally, we present a practical application wherein the FTEG, integrated with the flexible phase-change material heatsink, efficiently converts waste heat from a circular hot pipe into electricity, serving as a viable power source for smartphone devices. This work opens exciting possibilities for the future integration of flexible thermoelectric modules with flexible phase-change material heatsinks, offering a promising avenue for converting thermal waste heat into usable electricity. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Post-ball-milling-assisted solid-state synthesis of Bi4O4SeCl2: A low thermal conductivity material(2025-02-01);