Srinakharinwirot University Journal of Sciences and Technology

editorial board

2025-11-26T14:07:27+07:00

The Influence of the Quantity of Magnetic Materials Extracted from Electronic Waste on The Modulus and Electromagnetic Parameters of Polypropylene Composites

2024-06-07T10:58:36+07:00

This research investigated the influence of the quantity of magnetic materials on modulus and electromagnetic parameters. We ground transformer cores into powder in a ball mill. We analyzed the obtained powder using the X-ray diffraction technique, which revealed it to be iron oxide powder. We mixed the iron oxide powder with polypropylene at weights of 0, 5, 10, 15, 20, and 25 phr using an internal mixer. Control temperature, screw speed, and mixing time. Next, we used the two-roll mill to roll the material into sheets and cut test samples for each technique. Scanning electron microscopy (SEM) pictures revealed the spread of iron oxide powder in the polypropylene matrix. As the amount of iron oxide increased, the clusters got bigger. Dynamic mechanical properties tests showed that the iron oxide powder mixing increased the modulus of polypropylene at any temperature. The electromagnetic parameters, namely magnetization, permeability, and permittivity, vary linearly with the iron oxide content.

Species and Carbon Sequestration of Vascular Plants in Ban Nang Tho Seasonal Flooding Forest, Mueang Yang District, Nakhon Ratchasima Province

2024-09-24T09:20:58+07:00

Seasonal flooding forest are riparian forests that are continuously declining due to a lack of understanding about conservation and utilization among communities and relevant agencies. This research aims to study plant species and carbon sequestration efficiency in the community forest of Ban Nang Tho, Muang Yang District, Nakhon Ratchasima Province, which is one of the few remaining floodplain forest along the Mun River in the province. A survey of vascular plants in an area of 80 rai (approximately 32 acres) revealed 45 families, 113 genera, and 138 species of plants. The plant diversity index value was 3.66. The evenness value was 0.74. The family with the highest number of species was Fabaceae with 24 species, followed by Rubiaceae with 11 species, Phyllanthaceae with 7 species, and Anacardiaceae, Capparaceae, Euphorbiaceae, and Sapindaceae with 5 species each. The dominant plant species in the area included Streblus asper Lour., Sindora siamensis Teijsm. ex Miq., Dalbergia nigrescens Kurz, Diospyros rhodocalyx Kurz, Olax scandens Roxb., Schoutenia ovata Korth., Lagerstroemia floribunda Jack, Microcos tomentosa Sm., Combretum quadrangulare Kurz, and Brachypterum scandens (Roxb.) Wight & Arn. ex Miq., listed in order of their abundance. The top 5 plant species with the highest above-ground biomass, carbon storage, and carbon dioxide absorption were Dalbergia nigrescens Kurz, Pterocarpus macrocarpus Kurz, Streblus asper Lour., Sindora siamensis Teijsm. ex Miq., Diospyros rhodocalyx Kurz. Their above-ground biomass amounts were 30.66, 30.23, 17.33, 15.91, and 15.14 tons, respectively. Carbon storage amounts were 15.33, 15.11, 8.67, 7.96, and 7.57 tons of carbon, respectively. And carbon dioxide absorption amounts were 56.26, 55.47, 31.81, 29.20, and 27.79 tons of carbon dioxide, respectively.

Least Squares Method for The Mathematical Model of an Automotive Window Mechanism

2024-04-18T08:15:38+07:00

This research presents a system identification and mathematical modeling approach for an automotive window mechanism using Least Squares (LS) and Recursive Least Squares (RLS) estimation techniques due to the linearity of the automotive window mechanism system. The objective is to select the suitable dynamic model that can predict the position of the window mechanism and compare two parameter estimation methods between Least Squares (LS) and Recursive Least Squares (RLS) method. The experiment involves collecting input - output data using an ultrasonic sensor and Arduino-based data acquisition system. The collected data is used to estimate the system parameters for different model structures, including Autoregressive exogenous (ARX) and Autoregressive moving average exogenous inputs (ARMAX) models, at various model orders. The performance of each model is evaluated by comparing the simulated outputs with experimental data. The results indicate that the 4^th order ARMAX model with Recursive Least Square achieves the highest accuracy of 95.563%. When the 4^th order ARMAX model with Least Square achieves the accuracy of 94.862%. The findings of this research demonstrate that the selection of an appropriate model structure and estimation method significantly impacts the accuracy of system identification for an automotive window mechanism.

Improvement of Distribution Systems Affected by Voltage Drop at Load Bus Using Power Flow Estimation Methods

2024-10-31T22:05:44+07:00

This article presents the improvement of an electrical distribution system utilizing a 250kVA transformer that supplies power in a radial network configuration. The distribution system is modeled as a 6-bus system, with transmission line parameters determined based on conductor size, distance, and configuration. Power flow calculations are performed using the Gauss-Seidel method to estimate voltage and power losses in the power system (Case 1), identifying a voltage drop issue at Bus 4 is 199.68 V. To address this voltage drop, improvement method are proposed. In Case 2, the transformer is relocated to the load center network, resulting in an estimated voltage at Bus 4 is 207.03 V, a voltage increase is 3.68 % and a power loss reduction is 6.97 %. However, the voltage remains below the operational rated of 230 V. In Case 3, add a second transformer 50 kVA is installed at Bus 4, the voltage to the operational rated, with an estimated voltage increase is 15.18% and a power loss reduction is 24.93%. In Case 4, capacitors are introduced as an alternative to the 50kVA transformer, employing two sizes is 391 μF and 270 μF, while using the Power Loss Index (PLI) and Capacitor Suitability Index (CSI) to determine optimal installation locations, resulting estimated voltages at Bus 4 is 208.32 V and 206.55 V, corresponding to voltage increases is 4.33% and 3.44%, respectively. The capacitor-based approach further reduces power losses by 40.62% and 31.60%, respectively. The analysis results demonstrate that Case 2, while suitable for load distribution, is impractical due to the relocation costs and its inability to resolve the voltage drop issue. Case 3 improvement the voltage across the system and successfully mitigates the voltage drop at Bus 4 to meet the operational rated, making it appropriate for accommodating future load demands despite higher installation costs. Case 4 is effective for reducing power losses and improving power flow efficiency in systems where the voltage already meets the operational rated. This study provides guidance for planning improvements to the electrical distribution system, addressing voltage drop issues while enhancing power efficiency.

Effectively of Construction Wetland in Laboratory Science Wastewater Treatment

2024-05-12T16:20:02+07:00

This study aimed to determine the efficiency of wastewater treatment using a constructed wetland system. The research focused on wastewater from the Environmental Science analysis laboratory, Faculty of Science, Ubon Ratchathani Rajabhat University. The artificial wetland system was designed with three plant species: Typha angustifolia Linn, Canna Russian Red, and red lotus (Nymphaea sp.). The system consisted of 12 oval-shaped ponds, each measuring 0.89 x 1.18 x 0.3 m³. The treatment process followed a cycle of water retention for 5 days, followed by a 2-day drying period. Key water quality parameters, including pH, suspended solids, biological oxygen demand (BOD), chemical oxygen demand (COD), ammonia, total phosphorus, and chromium were analyzed. Statistical analyses, including percentage, mean, and one-way ANOVA, were employed. Results showed that experimental ponds with the plants exhibited higher wastewater treatment than that of control ponds without plants. Differences in plant species influenced treatment efficiency for suspended solids, BOD, COD, and total phosphorus. The statistical analysis indicated a significant difference (p<0.05) in the reduction of COD across the different treatments. Canna Russian Red demonstrated the highest treatment efficiency, achieving BOD removal of 92.41%, suspended solids removal of 91.23%, COD removal of 89.62%, ammonia removal of 69.52%, and total phosphorus removal of 89.85%. Chromium was not detected in any treatment units. Overall, no statistically significant differences in treatment efficacy were observed at the 95% confidence level.

Non-Cancer Health Risk Assessment from Lead and Cadmium Contamination in Rice Near the Municipal Waste Dumping Site in Ongkharak District, Nakhon Nayok Province

2025-02-11T12:56:43+07:00

This research aimed to study the amount of lead and cadmium contamination in rice fields near the waste dumping site in Ongkharak District, Nakhon Nayok Province. It was found that the level of lead in the soil was 0.178-0.253 mg/kg and cadmium was 2.326-3.314 mg/kg, which did not exceed the standard criteria according to the announcement of the National Environment Board on the determination of soil quality standards B.E. 2564. The level of lead and cadmium contamination in rice grains, they were 0.010-0.060 mg/kg and 0.433-0.791 mg/kg, respectively. The level of lead in all rice grain samples did not exceed the standard of the Ministry of Public Health Announcement (No. 414) B.E. 2563, but the level of cadmium in some samples was found to exceed the standard. The result of non-cancer health risk from oral intake from rice consumption by considering the HQ value, the results found that the HQ value of Pb was 0.01-0.06 in children and 0.01-0.04 in adults, which Indicates no significant health risk (HQ<1). However, for the risk of cadmium intake from rice consumption in the sample group found to have cadmium exceeding the standard, it was found that the HQ value was 1.32-2.55 in children 0.98-2.07 in adults, indicating that cadmium intake from rice consumption may cause health effects and risks (HQ>1).

Effects of Med Fai 62 Brown Rice Flour and Protein Sources on The Quality of Dried Instant Noodles

2025-04-08T10:25:15+07:00

This study investigated the optimal amount of brown rice flour from the Med Fai 62 variety by comparing the physical, chemical, and sensory properties, as well as consumer acceptance, of instant noodle products enriched with different protein sources. The results showed that the physical and chemical characteristics of instant noodles in which wheat flour was partially replaced by Med Fai 62 brown rice flour differed significantly from the control sample. Increasing the proportion of Med Fai 62 brown rice flour (10–30%) affected the lightness (L*), red-green (a*), and yellow-blue (b*) color values. Higher levels of brown rice flour resulted in a darker noodle color. The color values (L*, a*, and b*) ranged between 17.92–69.73, 3.35–11.00, and 6.10–29.88, respectively. As the proportion of brown rice flour increased, the L* and b* values decreased, while the a* values increased. Compared to commercial samples, the moisture content, water activity, and texture firmness of the instant noodles ranged between 0.39–12.95%, 0.13–0.61, and 0.38–29.73 N, respectively. Cooking time, cooking loss and water absorption ranged from 3.00–7.17 minutes, 1.68–7.13 times, and 25.32–31.65 grams, respectively. In terms of sensory quality, the instant noodles containing 10% Med Fai 62 brown rice flour received the highest overall liking score (8.23), which was not significantly different from the commercial instant noodle sample. The instant noodles with a 0.29% reduction in sodium chloride also received the highest overall liking score of 8.00. When comparing chemical properties and texture of the brown rice noodles enriched with protein, the moisture content, water activity, and firmness ranged from 5.28–8.04%, 0.58–0.66, and 14.50–17.48 N, respectively. These noodles exhibited increased cooking time and weight loss compared to the control. Sensory evaluation revealed that instant noodles with 10% Med Fai 62 brown rice flour enriched with soy protein powder received the highest overall liking score (7.87), while those enriched with cricket powder were not significantly different from the control. Therefore, dried instant noodles fortified with 10% Med Fai 62 brown rice flour, reduced sodium chloride by 0.29%, and enriched with soy protein or cricket powder have potential to a commercial product health-conscious consumer.

The Effects of Plant Growth Regulators from Endophytic Bacteria on Propagation of Rare and Economically Valuable Plants (Zingiberaceae) by Plant Tissue Culture Technique

2024-10-22T16:36:39+07:00

The purposes of this study were to investigate rare and economically valuable plants (Zingiberaceae) in Chaiyaphum Province and to expand their population by using tissue culture technique. The study's findings demonstrated that ginger plants could be gathered from the regions covered by the herb group community enterprises in the province of Chaiyaphum, which included Ban Tha Thang Kwian and the Thai Way Ban Sai Ngam. These two groupings are sources that plant for agricultural cultivation and gather species for conservation. It was found that a total of 4 genera and 8 species of ginger plants were planted and collected, such as ginger (Zingiber officinale Roscoe), Pyle (Zingiber cassumunar Roxb), Galangal (Alpinia galanga (L.) Willd.), Chinese keys (Boesenbergia rotunda L. Mansf.), Turmeric (Curcuma longa L.), Mango ginger (Curcuma mangga Valeton and Zijp), Pathumma (Curcuma alismatifolia), and White Okra (Curcuma parviflora). An interesting plant, White Okra samples were surface sterilized before propagated through plant tissue culture. This was achieved by first sterilizing with 20% Clorox for 10 minutes and then sterilizing them again with 10% Clorox for 10 minutes, resulting in a 96% sterility rate for the plant samples. Additionally, the plant samples could increase the most in number at 2.5 shoots per tissue piece. When MS medium supplemented with TDZ in combination with IAA derived from endophytic bacteria was used in place of commercial NAA (1:0.1 mg/L), a 100% shoot induction rate was achieved, with the highest average number of shoots at 2.25 shoots per explant. Moreover, the medium containing only IAA (0.1 mg/L) from isolate ZCK-8 resulted in the highest average number of roots and root length per explant. The results of the experiment indicated that the IAA hormone from the ZCK-8 isolate could successfully stimulate the growth of plant samples' shoots and roots comparable to the commercial hormone NAA.

Sustainable Production of Cordycepin and Adenosine from Cordyceps militaris Using Agro-Industrial Byproducts

2025-08-13T15:26:24+07:00

Agro-industrial byproducts are abundant, low-cost resources with strong potential for bioconversion into high-value bioactive compounds. This study explored the use of soybean hulls (SB-H), sugarcane bagasse (SC-B), and rice husk (RH-K) as alternative substrates for the cost-effective cultivation of Cordyceps militaris under solid-state fermentation, with jasmine brown rice (JBR) serving as the control. The results indicated that SB-H produced a biomass yield of 3.04 ± 0.06 g dry weight (DW), which was not significantly different from JBR (3.07 ± 0.06 g DW). However, SB-H significantly (p ≤ 0.05) enhanced the production of bioactive compounds, yielding cordycepin at 7.76 ± 0.26 mg/g DW, representing a 22.40% increase over the control, and adenosine at 0.47 ± 0.02 mg/g DW. In addition, cultivation with SB-H reduced the production cost per gram of dry biomass by 7.54%. Analysis of spent mushroom substrates (SMS) revealed high levels of residual compounds, with SB-H containing the highest residual cordycepin content (6.83 ± 0.16 mg/g DW), while SC-B contained the highest residual adenosine content (0.37 ± 0.02 mg/g DW), highlighting their potential for secondary utilization. These findings demonstrate that agro-industrial byproducts, particularly soybean hulls, can serve as sustainable and efficient alternative substrates for the cultivation of C. militaris, offering comparable biomass yield, enhanced bioactive compound production, cost reduction, and support for circular economy practices in medicinal mushroom cultivation.

Production of Hydrochar from Tea Waste for Fuel Through Hydrothermal Carbonization

2025-03-19T10:16:50+07:00

The objective of this study was to identify an effective approach for managing high-moisture tea waste from the tea beverage industry by comparing hydrothermal carbonization (HTC) and dry carbonization (CT) processes for producing hydrochar and char. Experiments were conducted at temperatures of 230–270 °C for 90 and 180 minutes, with a water-to-tea waste ratio of 5:1 (w/w). The percentage yield, higher heating value (HHV), elemental composition (ultimate analysis), physical properties (proximate analysis), and functional groups (FTIR) were analyzed. Results indicated that HTC at 250 °C for 90 minutes achieved an HHV of 5727.7 cal/g, the highest energy recovery efficiency (ERE) of 94.5%, and greater carbon retention and energy densification (ED) compared to CT at 270 °C under the same conditions. In contrast, CT exhibited higher ash content and a lower abundance of carbonyl (C=O) functional groups than HTC. FTIR analysis revealed that HTC reduced C–O and aliphatic C–H functional groups, while increasing CHx and C=O groups with rising temperature, corresponding to dehydration and decarboxylation reactions. This comparison highlights HTC as a suitable process for wet feedstocks such as tea waste, as it reduces drying requirements, operates at lower temperatures, and produces a product with superior energy performance and chemical properties compared to CT. Therefore, HTC has strong potential for further development into solid fuels, adsorbents, and soil conditioners.

Optimization of Biological Substance Production from Bacillus subtilis Strain OK1101 in A 10 L Stirred Fermenter

2025-09-12T10:00:12+07:00

Bacillus subtilis strain OK1101, isolated from soil, has been reported to produce amylase and cellulase enzymes and exhibits potential for inhibiting weedy rice germination by more than 50% at the flask scale. This study aimed to determine optimal conditions and develop a biocontrol formulation from B. subtilis OK1101 for managing weedy rice in paddy fields. The effects of medium composition and physical parameters were investigated using a 10 L bioreactor. Among the tested media, formulation T supported the highest growth and biomass production, yielding 3.01±0.19 g/L, with viable cell counts of 7.91±0.02 log CFU/ml and an optical density at 600 nm of 2.28±0.11. Furthermore, cultivation at an agitation speed of 200 rpm combined with an aeration rate of 0.07 vvm (volume of air per volume of medium per minute) was found to be optimal for microbial cell production. Under these conditions, the maximum biomass yield reached 11.97±0.76 g/L, with viable cell counts of 8.93±0.17 log CFU/ml and optical density at 600 nm of 0.64±0.13. These findings demonstrate that B. subtilis OK1101 can be efficiently cultivated under controlled bioreactor conditions, achieving enhanced production of biomass, enzymes, and biological substance when using an aeration rate of 0.07 vvm and agitation speed of 200 rpm.