Thai Science and Technology Journal

A Study of Bacterial Cellulose Prepared from Coconut Water Affecting on Natural Rubber Composite Reinforcement

Tanawut Wayupa, Nuttha Suksupap, Pakjirat Singhaboot, Chalao Thepchalerm — Thu, 30 Apr 2026 00:00:00 +0700

This study aimed to apply bacterial cellulose as a bio-based filler for natural rubber. Bacterial cellulose was prepared by culturing Acetobacter xylinum on Hestrin-Schramm (HS) medium using coconut water as a carbon source. The obtained bacterial cellulose was dried, ground into powder, and separated using a shaker sieve. The cellulosic functional groups were analyzed by fourier transform infrared spectroscopy (FTIR). Natural rubber composites were prepared by blending natural rubber, various chemicals, and bacterial cellulose using a double-roll mixer. The effects of the amount (1, 2.5 and 5 parts per hundred rubber, phr) and particle size (20, 40, 60, 80 and 120 mesh) of bacterial cellulose on the dimensional stability and mechanical properties, including tensile strength and elongation to break, of the natural rubber composites were investigated. The results showed that bacterial cellulose could be successfully synthesized, and that neither its particle size nor its content significantly affected the dimensional stability of the rubber. In addition, the use of 80 mesh (180 mm) bacterial cellulose at a ratio of 1 phr provided the highest tensile strength. However, the elongation to break of the different natural rubber composite formulations did not differ significantly.

Effect of Calcination Temperature on Elemental Composition, Crystal Structure and Surface Morphology of Caulerpa lentillifera Residue

Kedsarin Meemon, Anuwat Hassadee, Tippavan Hongkachern, Watinee Chanmee — Thu, 30 Apr 2026 00:00:00 +0700

This research investigates the effects of calcination at room temperature and at 600ºC, 700ºC, and 800 ºC for 4 hours on the elemental composition, crystal structure, and surface morphology of Caulerpa lentillifera residue. The analytical techniques employed include energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Elemental analysis revealed the presence of 15 elements. The carbon and oxygen contents of the Caulerpa lentillifera residue decreased as the calcination temperature increased. Moreover, the concentrations of chlorine and sodium increased particularly at 800ºC, reaching 48.03 wt% and 29.25 wt%, respectively. XRD analysis at 600°C, 700°C and 800°C showed distinct diffraction peaks corresponding to the pyrite phase (FeS₂) with a cubic crystal structure, specifically along the (111), (200), (220), and (311) planes, consistent with JCPDS No. 42-1340. SEM image indicated that increasing the calcination temperature resulted in a transformation from an amorphous fibrous morphology to well-ordered, fine crystalline structures. At 800°C, well-defined cubic geometric crystals were observed, consistent with the XRD results. These findings demonstrate that calcination temperature significantly influences both the elemental composition and crystalline structure of the biomass, indicating its potential for development as an adsorbent, catalyst, or ceramic material. The selection of an appropriate calcination temperature can determine the desired material properties, for instance, utilizing the increased sodium and chlorine content for adsorption applications, or employing the FeS₂ phase as a catalyst.

Genotoxicity Evaluation of Zanthoxylum myriacanthum Wall. Ex Hook.f. Extract Using in vitro Micronucleus Assay

Tiyanee sahad, Nathaphat Harnkit, Pornchai Sincharoenpokai, Sarayut Radapong — Thu, 30 Apr 2026 00:00:00 +0700

Zanthoxylum myriacanthum, commonly known as Ma-Khwan, is a traditional medicinal plant predominantly found in the northern part of Thailand. Its fruits are extensively used in culinary practices and traditional medicine. However, comprehensive safety and toxicity data on its extracts remain limited. This study aimed to evaluate the genotoxic potential of Z. myriacanthum fruit extract using the in vitro micronucleus assay in human TK-6 lymphoblastoid cells, following the OECD Test Guideline No. 487. The extract was tested under three exposure conditions: short-term treatment with and without metabolic activation (S9 mix) for 4 hours, and long-term treatment without S9 mix for 24 hours. The results indicated that the extract did not induce a statistically significant increase in micronucleus frequency compared with the concurrent negative controls at any tested concentration. These findings suggested that the fruit extract of Z. myriacanthum does not exhibit genotoxicity under the specified experimental conditions. The study was conducted in accordance with OECD Good Laboratory Practice (GLP) standards and aligned with the Thai Food and Drug Administration guidelines for herbal product development. Nonetheless, further in vivo toxicity assessments are required to fully substantiate its safety profile, support consumer confidence, and facilitate its potential application in commercial product registration.

Analysis of Rail Buckling Due to High Temperature

Monchai Prukvilailert — Thu, 30 Apr 2026 00:00:00 +0700

The buckling of railway tracks during Thailand’s summer season occurs frequently and is a major cause of problems in rail transport, including increased track maintenance, rail replacements, and even train derailments. This research analyzes the causes of track buckling due to rising rail temperatures using the finite element method with linear buckling analysis. The results indicate that fastening devices installed between the rails and sleepers play a critical role in preventing track buckling as the rail temperatures approach critical levels. For a standard 25-meter-long rail, when at least 25 of the 30 fastening components are properly installed and securely connected to both the rail and the sleepers, the likelihood of rail buckling can be effectively reduced. Under these conditions, the critical buckling temperature of the rail increases to above 80 °C.

Calibration and Field Testing of a PM2.5 Monitoring Station Utilizing an Electrostatic Sensor with Real-time, Continuous Online Reporting

Thu, 30 Apr 2026 00:00:00 +0700

This research aims to calibrate and field-test a PM2.5 dust measurement station that operates using an electrostatic sensor. The system is capable of measuring, recording, and displaying data online through a web browser. The developed prototype utilizes locally sourced materials and equipment, replacing imported components. The system can measure and collect dust samples within a range of 0.1 to 5,000 µg/m³, with a processing time of less than 1 second. It is capable of continuous operation for up to 3,000 hours without maintenance or component replacement. The study focused on calibrating dust mass concentration measurements. The measurements were validated against a standard PM2.5 monitor using the Federal Equivalent Method (FEM) Group 3, as specified by the United States Environmental Protection Agency in 40 CFR Part 50, under laboratory conditions. Field tests were also performed under real-world conditions in Nakhon Phanom Province. The results from both laboratory and field tests showed that the measured dust concentration trends were consistent and comparable to those obtained using the standard method (40 CFR Part 50, U.S. EPA). Additionally, the system is capable of continuously reporting real-time data via the MQTT protocol, with data accurately stored in a time-series database (TSDB) without loss. The system enables rapid querying and retrieval of historical data, and the dashboard loads data from the TSDB in less than 1 second, demonstrating its efficiency in data processing and visualization.

Assessment of Antimicrobial and Antioxidant Activities of the Extracts from a Thai Traditional Medicine Herbal Recipe for Infectious Disease

Thu, 30 Apr 2026 00:00:00 +0700

This study aimed to evaluate the antimicrobial and antioxidant activities of crude extracts from a Thai traditional medicine recipe developed by Luang Phinitphonnikon. The medicinal plants were extracted using two solvents: ethyl acetate and ethanol. The crude extracts were evaluated for the antimicrobial and antioxidant activities using the colorimetric broth microdilution method, DPPH, and ABTS free radical scavenging assays, respectively. The antimicrobial efficacy of the extracts was tested against nine human pathogenic microorganisms: Staphylococcus aureus ATCC 25923, Methicillin-resistant Staphylococcus aureus (MRSA) SK1, Staphylococcus epidermidis, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 90028, Cryptococcus neoformans ATCC 90112, Microsporum gypseum, and Talaromyces marneffei. The ethanol extract exhibited the highest inhibitory effect against Gram-positive bacteria (S. aureus, MRSA, and S. epidermidis), with minimum inhibitory concentrations (MICs) ranging from 0.025 to 6.4 mg/mL. Regarding antioxidant activity, the ethanol extract showed IC₅₀ values of 37.29 ± 1.03 µg/mL for the DPPH assay and 276.65 ± 0.41 µg/mL for the ABTS assay. In addition, total phenolic and flavonoid contents were analyzed by the Folin-Ciocalteu method and the colorimetric aluminum chloride method, respectively. The ethanol extract showed total phenolic and flavonoid contents of 67.00 ± 0.51 mg GAE/g extract and 15.20 ± 1.00 mg QE/g extract, respectively. These findings suggest that this Thai traditional medicine recipe is a promising source of bioactive compounds with both antimicrobial and antioxidant properties.

Developing Fermented Bio Extracts from Agricultural Waste to Increase Cassava Production

Sakol Thongprapa; Suparatchai Vorarat, Surasak Janchai, Nat Nakkorn — Thu, 30 Apr 2026 00:00:00 +0700

Since the price of chemical fertilizers has increased significantly due to conflicts among major fertilizer producers and exporters (Russia and Ukraine), the cost of crop production in Thailand has risen, resulting in lower yields. Organic fertilizers offer an alternative approach for supplying nutrients to the soil and enhancing crop productivity. Accordingly, this research aims to develop a process for transforming agricultural waste materials into biologically fermented products that meet the fertilizer standards specified by the Department of Agriculture. These fermented products were applied to experimental cassava plants, and crop yields were assessed. Cassava leaves and water from a circulating pump were used as raw materials for fermentation. The experiment was conducted using an A x B factorial design in a completely randomized design (CRD), with two replicates (n = 2). Key parameters (temperature, pH, and dissolved oxygen) were monitored daily during the 30-day fermentation process, and the resulting products were analyzed for nitrogen (N), phosphorus (P), and potassium (K) contents. The results showed that Process 4 produced a fermented product containing all essential macronutrients at levels meeting the required criteria. Furthermore, when bio-fermented products were applied to Cassava plant experimental plots, Process 4 yielded the best results in terms of fresh tuber weight and starch content. In summary, the findings indicate that the process developed in this study for producing bio-fermented products can enhance agricultural productivity and can serve as a guideline for sustainable agricultural practices, offering economic, social,environmental, and ecological benefits.

Development of Blast Disease Resistance in Khao Dawk Mali 105 Plus IV Rice Variety Using all Four Alleles (Pi2, Pi9, Piz and Piz-t) of Pi9 Gene

Rattigan Kaedphol, Tanapon Chaisan, Nonglak Parinthawong, Tanee Sreewongchai — Thu, 30 Apr 2026 00:00:00 +0700

Khao Dawk Mali 105 (KDML105) is a premium Thai rice variety widely favored for consumption; however, it is highly susceptible to blast disease. This study aimed to introgress four alleles of the Pi9 gene group—Pi2, Pi9, Piz, and Piz-t—from resistant donor lines IRBLZ5-CA, IRBL9-W, IRBLZ-FU, and IRBLZT-T, respectively, into the improved KDML105⁺⁴ variety through marker-assisted backcrossing. Simple sequence repeat (SSR) markers RM225 and Naro1 were used to detect the presence of blast resistance genes and the fragrance gene, respectively. Additionally, amplified fragment length polymorphism (AFLP) markers were employed to identify individuals with genetic backgrounds closely resembling that of the recurrent parent. Phenotypic traits were also evaluated to support the selection process. The results successfully identified 10 BC₂F₂ lines per cross that carried the targeted resistance genes and exhibited the desired phenotypic traits, resulting in a total of 40 selected lines. These lines are recommended for further evaluation under field conditions to assess the stability of blast resistance and yield performance. Moreover, future studies should examine their resistance against diverse blast pathogen races under real-world growing environments, particularly in high-risk areas. The ultimate goal is to develop new rice lines suitable for cultivation in areas vulnerable to blast outbreaks and capable of meeting the practical needs of local farmers.