Suranaree Journal of Science and Technology

ELECTRICAL AND MAGNETIC PROPERTIES OF MULTIFERROIC Co0.6Zn0.4Fe1.7Mn0.3O4 DOPED 0.99Bi0.47Na0.47Ba0.06Tio3-0.01Ba(Sn0.70Nb0.24)O3 CERAMICS SYNTHESIZED VIA THE SOLID-STATE COMBUSTION TECHNIQUE

Anupong Luangpangai — 2025-08-19

Multiferroic (1-x)[0.99Bi_0.47Na_0.47Ba_0.06TiO₃-0.01Ba(Sn_0.70Nb_0.24)O₃]-xCo_0.6Zn_0.4Fe_1.7Mn_0.3O₄ (abbreviated as BNBT-BSN-xCZFMO) ceramics with x ranging from 0 to 0.20 were fabricated using the solid-state combustion technique. The effect of varying BNBT-BSN : CZFMO ratios on the phase structure, microstructure, electrical and magnetic properties was investigated. X-ray diffraction (XRD) analysis of pure BNBT-BSN showed a perovskite structure with rhombohedral and tetragonal phases. The doped BNBT-BSN-xCZFMO ceramics displayed coexisting rhombohedral, tetragonal, and cubic spinel phases, with the cubic spinel phase increasing when the CZFMO content increased. In addition, the XRD peaks shifted to higher angles as the CZFMO content increased, indicating a decrease in lattice parameters. The dielectric constant decreased with higher CZFMO content and higher frequencies. The pure BNBT-BSN ceramic exhibited a saturated P-E loop with a P_max of 33.2 µC/cm², P_r of 26.1 µC/cm², and an E_c of 14.5 kV/cm. With increased CZFMO content, non-saturated and bloated P-E loops with lower P_max, P_r, and E_c were observed, implying a rise in the leakage current. The addition of CZFMO induced ferromagnetic behavior in the ceramics, leading to an increase in M_s and a reduction in H_c as CZFMO content increased. The magnetoelectric coupling coefficient of BNBT-BSN-xCZFMO ceramics continuously increased with higher CZFMO content.

ELECTRIC AND MAGNETIC PROPERTIES OF Ni0.475Zn0.475Li0.025Al0.025Fe2O4 DOPED (Bi0.5Na0.5)0.94Ba0.06TiO3 CERAMICS PREPARED BY THE SOLID-STATE COMBUSTION METHOD

Wiwat Pattanakasem — 2025-08-20

In this study, we synthesized (1-x)((Bi_0.5Na_0.5)_0.94Ba_0.06TiO₃)-x Ni_0.475Zn_0.475Li_0.025Al_0.025Fe₂O₄[(1-x)BNBT-xNZLAF] ceramics with x= 0, 0.05, 0.10, 0.15, and 0.20 using the solid-state combustion method. The phase formation, microstructure, and dielectric, ferroelectric, ferromagnetic, and magnetoelectric properties were investigated. BNBT and NZLAF powders were calcined at 750°C and 900°C for 2 h., respectively. The calcined powders were then mixed in various ratios to produce (1-x)BNBT-xNZLAF composites, which were sintered at 1125°C for 2 h. X-ray diffraction analysis indicated that undoped BNBT ceramics exhibited a typical perovskite structure with coexisting rhombohedral (R) and tetragonal (T) phases. With increasing NZLAF content, the cubic spinel (C) phase emerged with the R and T perovskite phases. Rietveld refinement indicated a higher percentage of the C phase as x increased. When x increased from 0 to 0.10, the average grain size and density increased (from 1.0 to 9.8 m and 5.45 to 5.61 g/cm³, respectively) followed by a drop at higher NZLAF levels. Doping BNBT ceramics with NZLAF resulted in a reduction in the dielectric constant (ε_r), dielectric loss (tan δ), and remnant polarization (P_r). The undoped BNBT ceramic showed a saturated P-E hysteresis loop, while NZLAF doped ceramics exhibited unsaturated P-E loops and increased leakage current. Magnetic measurements showed a transition from diamagnetic to ferromagnetic behavior with NZLAF doping. As x increased, the remnant magnetization (M_r), saturation magnetization (M_s), and magnetoelectric coefficient also increased (M_r»0.058 emu/g, M_s»3.594 emu/g, and ME_coefficient »2.64 mV/cm•Oe at x=0.25). These results suggest that NZLAF-doped BNBT ceramics hold potential for multiferroic material applications.

IN SILICO IDENTIFICATION OF SECONDARY METABOLITES FROM AQUATIC STREPTOMYCES ISOLATE WITH ANTIYEAST AND ANTICANCER ACTIVITIES

Jirayut Euanorasetr — 2025-08-15

This study explored the potential of bioactive metabolites from Streptomyces strain WHD3007-4. Isolated from a Nile tilapia pond, aquatic Streptomyces sp. WHD3007-4 was cultured in four media (International Streptomyces Project-2 Medium (ISP2), 301, Starch Casein Broth (SCB), and Bennet’s Broth (BN). Its secondary metabolites were extracted using ethyl acetate and acetone at a ratio of 15:2 (v/v). The cytotoxicity of all crude extracts on the human colorectal cancer cell line HCT-116 was assessed using the MTT assay. The percentage of viable HCT-116 cells was lowest with Streptomyces sp. WHD3007-4 in the SCB medium (36.20%). The antiyeast activity of the crude extract from Streptomyces sp. WHD3007-4 in SCB medium was assessed against Candida tropicalis (TISTR No. 5136) using the disk diffusion method. The crude extract effectively inhibited C. tropicalis growth at 2 mg. Known compounds in the crude extract from Streptomyces sp. WHD3007-4 in different media were identified using liquid chromatography-tandem mass spectrometry, with the data processed using MZmine 3 for molecular networking and spectral library searching on the Global Natural Products Social Molecular Networking (GNPS) web platform. Several candidate anticancer molecules were identified: kynurenic acid, brevianamide F, N-(2-hydroxyphenyl) acetamide, and decumbenone A. These results suggest that Streptomyces sp. WHD3007-4 is a potential source of antiyeast and anticancer agents.

PHASE FORMATION AND ELECTRICAL PROPERTIES OF Ba0.91Ca0.09Ti0.916Sn0.084O3-0.1WT%ZnO -0.1WT%MnO2 LEAD-FREE FERROELECTRIC CERAMICS SYNTHESIZED VIA THE SOLID-STATE COMBUSTION METHOD

Sununta Yimsabai — 2025-08-20

This work investigated the effect of firing temperatures on the phase formation, microstructure, and electrical properties of Ba_0.91Ca_0.09Ti_0.916Sn_0.084O₃-0.1wt%ZnO-0.1wt%MnO₂ (BCTS-ZnMn) lead-free ferroelectric ceramics synthesized via the solid-state combustion method. Glycine was used as fuel to reduce the synthesis temperature. The samples were calcined at temperatures from 1050 to 1250°C (in 50°C increments) for 3 h and sintered from 1250 to 1450°C (in 50°C increments) for 3 h. A pure perovskite phase was found in the powders calcined above 1100°C. The phase structure, microstructure, dielectric and ferroelectric properties of the ceramics were examined. The X-ray diffraction (XRD) analysis for the ceramics revealed the presence of tetragonal (T) and orthorhombic (O) phases in all the ceramics. The average particle size and average grain size increased with increasing firing temperatures. The density, dielectric constant at the Curie temperature (ɛ_c), P_r and P_s tended to increase with increasing sintering temperatures, up to 1400°C, and then decreased at 1450°C. The ceramic sintered at 1400°C exhibited the highest density (5.89 g/cm³), dielectric response (ɛ_c = 13324) and good ferroelectric behavior (P_r = 8.67 µC/cm², P_s = 17.92 µC/cm² and E_c = 0.99 kV/cm)

EVOLUTION OF PHASE FORMATION, MICROSTRUCTURE, AND ELECTRICAL PROPERTIES OF BaTi0.91Sn0.09O3 LEAD-FREE CERAMICS FOR DIFFERENT CALCINATION AND SINTERING TEMPERATURES

Wiwat Pattanakasem — 2025-08-20

Lead-free BaTi_0.91Sn_0.09O₃ (BTS) ceramics were fabricated by the conventional solid-state reaction method. The evolution of phase, microstructure, dielectric, and ferroelectric properties of BTS powders and ceramics was examined at different calcination (1175-1250°C for 4 h.) and sintering (1375-1450°C for 2 h.) temperatures. X-ray diffraction (XRD) revealed that the calcined powders had perovskite structures, with a secondary BaSnO₃ impurity phase when calcined below 1200°C. The BTS ceramics displayed a secondary Ti_0.85Sn_0.15O₂ phase at a sintering temperature of 1375°C, while no impurity phases were detected at 1400-1450°C. Rietveld refinement indicated coexisting orthorhombic (O), tetragonal (T), and cubic (C) phases in all samples. The O phase increased with sintering temperatures up to 1425°C before decreasing, while the T and C phases decreased for sintering temperatures up to 1425°C before increasing. When the sintering temperature increased from 1375°C to 1425°C, the density, dielectric constant at the Curie temperature (ε_C), and maximum polarization (P_max) increased from 5.90 to 5.98 g/cm³, 9,533 to 12,538 and 15.07 to 15.36 μC/cm², respectively, before decreasing. In contrast, the dielectric loss (tan δ), remanent polarization (P_r), and coercive electric field (E_c) decreased from 0.036 to 0.020, 8.42 to 7.48 μC/cm², and 3.49 to 1.86 kV/cm, respectively, when the sintering temperature increased from 1375°C to 1425°C, before slightly increasing. The BTS ceramic sintered at 1425°C showed the highest density, a well-packed microstructure, superior dielectric properties, and high P_max. The increased orthorhombic phase content reduced P_r and E_c, making this ceramic suitable for dielectric capacitor applications.

INCREASED RHINACANTHIN PRODUCTION IN RHINACANTHUS NASUTUS HYDROPONICS BY DUAL ELICITATION USING CHITOSAN AND TRICHODERMA HARZIANUM

Thongtham Suksawat — 2025-08-07

A highly efficient hydroponic cultivation system was developed to enhance rhinacanthin production in Rhinacanthus nasutus. Within this framework, dual elicitation using chitosan (CHI) and Trichoderma harzianum extract (THE) was identified as a promising technique, strategically employed to increase the overall yield of rhinacanthins. R. nasutus hydroponics were treated with CHI (0.15 mg ml^-1) and THE (1.0 mg ml^-1) either simultaneously or sequentially, with elicitor exposure periods ranging from 24 to 96 h. The total rhinacanthin content (rhinacanthin-C, -D, and -N) in roots and leaves was analyzed using HPLC. Simultaneous dual elicitation with CHI and THE resulted in lower rhinacanthin levels in both leaves and roots compared to single elicitation with either agent. Among the treatments, the highest rhinacanthin contents in the leaves (7.05% w/w) and roots (9.65% w/w) were observed with sequential dual elicitation, in which 0.15 mg ml^-1 CHI was applied for 48 h, followed by 1.0 mg ml^-1THE for 24 h and 72 h, respectively. In contrast, a reversed sequential dual elicitation, in which 1.0 mg ml^-1THE was applied for 24 h followed by 0.15 mg ml^-1 CHI for 72 h and 48 h resulted in rhinacanthin contents of 7.34% and 7.32% w/w in the leaves and roots, respectively. The present study demonstrates an effective approach for enhancing rhinacanthin content in hydroponically cultivated R. nasutus through sequential dual elicitation using CHI and THE.

COMPUTATIONAL STUDY ON STRUCTURAL, ELECTRON STATES, AND MUON TRAPPING SITES IN GUANINE

Wan Nurfadhilah Zaharim — 2025-08-18

Knowledge of muon trapping sites in matters is needed in the interpretation of Avoided Level Crossing-Muon Spin Resonance (ALC-µSR) experiment. Additionally, accurate computation on the trapped muon hyperfine interaction is instrumental in the planning of applied magnetic field strength for the experimental measurement. Density Functional Theory quantum mechanical method was employed to predict the most probable sites of muon addition in isolated guanine nucleobase. Utilizing B3LYP functional coupled with 6-311G++(d,p) basis set, the HOMO-LUMO gap was calculated to be 5.147 eV. The frontier molecular orbitals show significant delocalization characteristics. Molecular electronic potential map indicates that N2, O5, and N7 areas are favoured for alkylation. Out of eight possible muon addition sites, C8 was found to have the lowest total energy and therefore is the most probable location for the trapping of implanted muon. Natural Population Analysis reveals that the trapped muon is covalently bonded to the C8 atom with a bond order of 0.903. The calculated muon hyperfine coupling constant at the C8 site is 337.4 MHz. The applied magnetic field strength for ALC-µSR resonance to occur for C8 site is predicted to be around 14,000 Gauss. These findings provide valuable insights into muon behavior in nucleobases, contributing to a more precise interpretation of ALC-µSR experimental data and enhancing the design of future studies on muon interactions in biomolecular systems.

BANDGAP VOLTAGE REFERENCE USING TRIPLE CASCODE OPERATIONAL AMPLIFIER

Komal Duhan — 2025-08-18

Bandgap Voltage reference (BGR) circuits are crucial components in analog circuits. In this paper, a BGR circuit capable of obtaining a reference voltage of 1.0435 V is proposed. In the proposed BGR circuit, Miller compensated two-stage Triple Cascode Operational Amplifier (Op-Amp) has been used which achieves a higher gain of 104.1db and Phase Margin of 73.78 degrees with 1.8V supply voltage using 90nm technology. The proposed BGR circuit achieves 4.51 ppm/OK of temperature coefficient and 0.4375 mV/V of line regulation. The designed BGR circuit can be used in analog applications.

STUDY OF PHYSICAL AND OPTICAL PROPERTIES OF SUGARCANE LEAF ASH GLASS DOPED WITH COPPER OXIDE

Pattraporn Saengka — 2025-08-19

In this research, the physical and optical properties of sugarcane leaf ash doped with copper ions in glass were investigated. The composition of sugarcane leaf ash was analyzed at different sintering temperatures using X-ray fluorescence (XRF) spectroscopy, revealing the highest SiO₂ content (69 wt%). The glass formula was developed based on the ratio (50-x)SiO₂ (with sugarcane leaf ash substituting for SiO₂ and CaO): 25B₂O₃: 10Na₂O: 8CaO: 7SrO: xCuO, where x represents the concentration of copper oxide (0.00, 0.10, 0.20, 0.30, 0.40, and 0.50 mol%). The results showed that the density and refractive index increased with increasing CuO concentration, while the molar volume decreased. The absorption spectra of the glass in the wavelength range of 350-1,100 nm was measured and showed a peak around 775 nm, corresponding to the ²B₁g → ²B₂g transition of Cu²⁺. The studied glass exhibited greenish-blue color coordinates, confirmed by CIE Lab* color measurements.

A STUDY OF THE PHYSICAL AND OPTICAL PROPERTIES OF PINK GLASSES MADE FROM SUGARCANE LEAVES IN NAKHON PATHOM PROVINCE

Pornnapha Mangthong — 2025-08-07

This research aims to study of the physical and optical properties of pink glasses made from sugarcane leaves in Nakhon Pathom Province. Sugarcane leaves were subjected to baking at temperatures of 1000°C. It was observed that as the SiO₂ content increased, the color of the glass changed. The glass formula was designed according to the ratio of (40-x) SiO₂: 20B₂O₃: 25Na₂O: 15CaO: xEr₂O₃ mol%, where x represents the concentration of Er₂O₃ in the glass. The ground mixture was melted in a porcelain crucible at a temperature of 1,200°C in an electric furnace for 3 hours under normal atmospheric conditions. Subsequently, the homogeneous melts were formed and quenched into a preheated graphite mold, followed by immediate annealing at 500°C. The glass was then slowly cooled to room temperature. Afterward, the colored glass samples were analyzed, revealing that the density and refractive index of the glass samples ranged from 2.6060 to 2.7548 g/cm³ and 1.5465 to 1.5664, respectively. All glass samples exhibited a hardness value of 5.5 on the Mohs scale.

FOOD INNOVATION FOR EXTENDING SHELF LIFE OF WHITE SHRIMP, TILAPIA, AND NAM DOK MAI MANGO WITH CHITOSAN EXTRACTED FROM LEFTOVER WHITE SHRIMP SHELL

Bpantamars Phadungchob — 2025-08-19

This study repurposes white shrimp shells, an agricultural waste, to extract chitosan—a natural biopolymer with antimicrobial properties—for enhancing food safety and extending shelf life. Chitosan was extracted using a simple, cost-effective process involving chemical treatments and drying. The extracted chitosan, characterized as high DA chitosan (% DA = 75.93 ± 1.40) with enhanced solubility, with functional groups similar to those found in commercial chitosan. Preservation tests demonstrated that the extracted chitosan effectively extended the shelf life of unpeeled shrimp by 3-5 days, peeled shrimp by 1-2 days, and tilapia by 2-3 days while maintaining sensory quality, including color, pH stability, and odor control. For Nam Dok Mai mangoes, chitosan coatings at the peduncle area preserved marketable quality for up to 10 days. This method provides a cost-effective, sustainable solution for local producers, promoting value-added agricultural practices and benefiting both seafood and fruit preservation.

STUDIES OF PRESERVATION OF LOTUS POLLENS AND INTERSPECIFIC LOTUS BREEDING

Vichai Puripunyavanich — 2025-08-08

Lotus (Nelumbo nucifera) pollen viability was studied under various conditions, including 30°C room temperature, 8°C refrigerator, and -20°C freezer for storage periods of 7, 10, and 14 days, respectively. The pollens were stained with acetocarmine for pollen survival testing. Lotus pollens stored for 7 days at room temperature and 8°C refrigerator exhibited the highest viability percentages (88.00% and 89.00%, respectively). Subsequently, lotus anthers were irradiated with gamma rays at 0, 30, and 60 Gy and preserved at 8°C refrigerator for 7, 10, and 14 days. Examination of pollen viability showed that there was no statistically significant difference between the viability of pollens irradiated at 30 Gy and non-irradiated treatment after 7 days. However, over a storage period of 14 days, the survival percentage of 30-Gy irradiated pollen decreased more rapidly compared to the non-irradiated. Pollens from the mutant yellow lotus N. lutea were collected at Queen Sirikit Botanical Garden, Chiangmai, and stored under 8°C as the optimal condition for preserving lotus pollens and transferred to Thailand Institute of Nuclear Technology, Nakhon Nayok for interspecific crosses with white native lotus flowers (N. nucifera ‘Boontarik’). Only four plants survived and only one could flower. These cultivars successfully adapted to the Thai central plain climate and flowered after 4 months of planting. Plant characteristics were similar to Thai native ‘Boontarik’ lotus but its flowers showed creamy petals. This cultivar was unofficially named Nelumbo ‘Yellow Boontarik’.