RMUTP Research Journal Sciences and Technology

Study of the Extreme Values of River of Quality in the Tha Chin River, Bang-Len District, Nakhonpathom Province

2025-09-12T16:33:47+07:00

This study investigated the variables affecting water quality in the Tha Chin River, Bang-Len District, using the Generalized Extreme Value (GEV) distribution to analyze water quality parameters, including pH, dissolved oxygen (DO), electrical conductivity (EC), and temperature (Temp). The results indicate that higher EC values reflect increased dissolved substances such as nutrients or chemicals, while elevated water temperature suggests a continual decline in the river’s water quality. The findings also show that rising temperature levels indicate a consistent and worsening trend of water quality degradation each year. The main causes of this problem are pollutant discharges from communities, industries, and agricultural activities, as well as inappropriate water flow management. Government agencies, such as the Department of Environmental Quality Promotion and the Pollution Control Department, have implemented measures to control wastewater discharge, improve water quality, and promote community participation in monitoring programs along the Tha Chin River. These initiatives include the development of wastewater treatment systems, integrated management strategies, and environmental impact assessments. Furthermore, climate change characterized by rising temperatures and decreasing rainfall poses a direct threat to regional water resources.

Development of Demand Side Management Strategies to Reduce Peak Load in Educational Buildings through Electrical Load Trend Analysis from Real-Time Monitoring Data

2025-07-01T16:28:07+07:00

This study focuses on analyzing the peak load trends and developing Demand Side Management (DSM) strategies to enhance energy efficiency in the Industrial Technician Building at the College of Industrial Technology and Management, Rajamangala University of Technology Srivijaya, using real-time monitoring data from December 2024 to February 2025. The results show that the average daily peak load from December 1–10, 2024, was 151.3 kW with a Load Factor of 0.59, the lowest compared to the period from January 1–10, 2025, where the peak load increased to 162.4 kW and the Load Factor rose to 0.63, indicating a better energy balance early in the year. The highest peak load of 165.4 kW with a Load Factor of 0.63 occurred from January 21–31, 2025, showing increased energy use during the summer season. In February, the peak load decreased to 154.1 kW, possibly due to changes in energy usage behavior. The study suggests that redistributing the electrical load and using an automatic load control system can reduce peak load and improve energy efficiency. Furthermore, developing an intelligent energy system and implementing Demand Response can enhance long-term energy management. Economic analysis indicates that the DSM project can break even in 3.42 years and generate a net profit of approximately 200,000 baht within 5 years by utilizing appropriate DSM techniques, such as changing energy usage behavior, using renewable energy, load control, and energy-saving technologies, all of which will help reduce the load on the electrical system and improve energy efficiency in the building.

Effects of Planting Media and Plant Care Practices on Ex Vitro Rooting of Philodendron pedatum (Hook.) Kunth

2024-11-11T09:23:50+07:00

Philodendron pedatum (Hook.) Kunth is widely used as an ornamental plant for cutting leaf, gardening, or pot plant to decorate buildings. The plant tissue culture technique is employed to propagate this economically important crop for the high demand of the ornamental plant industry. However, the transplantation of in vitro rooted plants frequent results in plant death, which is causing a significant huge loss in plant propagation resource. This research aimed to evaluate the ex vitro rooting induction of P. pedatum. In vitro young shoots, 1 cm in height with 3 leaves, were cultured on Murashige and Skoog (MS) agar medium and compared with in vitro-raised plants grown under ex vitro conditions on peat moss (10 plants/condition with 3 times repeated). The results showed that all plants grown ex vitro were able to survive and rooting. Additionally, ex vitro plants exhibited data of new root number, new root length, and overall fresh weight significantly higher than in vitro plants. Planting media (peat moss, coco peat, a mixture of 1 peat moss : 1 coco peat) and plant care substance application (distilled water, MS liquid medium, Flavogen^®, Osil^®) were subsequently studied to identify the most suitable substrate for ex vitro rooting (10 plants/treatment with 3 times repeated). The findings revealed that using peat moss as the planting material combined with Flavogen^®, an agrochemical, as the plant care substance resulted in the highest shoots and roots growth. This research will solve the problem of plant death after transplantation and could help reduce the cost of propagating P. pedatum using plant tissue culture techniques.

The The Optimization of Cassava Transportation to Reduce Carbon Emission

2026-03-18T11:49:05+07:00

This research utilized Genetic Algorithm (GA) to optimize cassava transportation routes from cultivation fields to nearby collection yards, with the objective of minimizing CO₂ emissions based on optimized distances. Data collected included plot coordinates, plot size, vehicle type, vehicle weight, and payload capacity for each vehicle type to collection yard A, as well as coordinates of two alternative nearby collection yards, B and C. Four vehicle types, including tractor, farm tractor, 6-wheel truck, and pickup truck, were analyzed in transporting cassava from 20 surrounding plots to collection yard A, with each delivering different volumes of cassava. The GA-based optimization of routing grouped the 20 plots into efficient collection routes servicing three different yards (A, B, and C), achieving a total of 18 optimized trips, which the results section that the workload was equally distributed, with each yard (A, B, and C) receiving 6 trips to ensure operational consistency across all route and payload identified a required vehicle capacity of 17,000 kg to satisfy the minimum theoretical trip demand. When CO₂ emissions were calculated along the optimized route, the observed emissions from actual operations were substantially higher than the GA-derived values. Total CO₂ emissions GA were decreased carbon emissions by up to 67.2 – 68.1 % compared to using Tractors and Farm tractors, 54.6 % when using 4-wheel pickup trucks and 0.09 % for the 6-wheel trucks. The results demonstrate that GA driven optimization significantly enhances agricultural logistics by reducing transportation time, costs, and environmental impact through the strategic selection of collection yards and vehicle types

Combustion Characteristics of a Small Diesel Engine Fueled with Ethanol and Polyethylene Glycol as Ignition Improver during Start of Engine

2025-10-06T08:26:42+07:00

This research aims to analyze the performance and combustion characteristics of a small diesel engine fueled by ethanol blended with Polyethylene Glycol (PEG) as an ignition improver. The experiments were conducted on a single-cylinder, Direct Injection (DI) diesel engine under no load and at maximum fuel position. The concentration of PEG was varied from 18% to 35% by weight. The experimental results revealed that the PEG proportion is a factor influencing engine startability; the engine failed to start when the PEG concentration was below 18%. Combustion analysis indicated that increasing the PEG concentration led to an advanced start of combustion (SOC) and a significant reduction in ignition delay. These improvements were directly correlated with a decrease in the number of misfire cycles. The findings of this study can serve as a guideline for determining the optimal additive proportions for utilizing ethanol in agricultural diesel engines.

Biomass Productivity and Antioxidant Composition of Marine Microalga Tisochrysis sp. TISTR 11470 Under Outdoor Cultivation Condition

2025-10-22T14:11:49+07:00

This study aimed to evaluate the growth performance and biochemical composition of the marine microalga Tisochrysis sp. TISTR 11470 cultivated under outdoor cultivation using white rectangular plastic tanks with a volume of 600 L over a 9-day period. The results revealed a continuous increase in cell density, as indicated by the optical density at 750 nm (OD₇₅₀), which rose from 0.10 on day 1 to 0.50 on day 9. The culture exhibited a highest specific growth rate of 0.58 day^-1 at day 1, reflecting efficient photosynthetic adaptation under outdoor conditions. The pH increased from 8.54 to 9.33, while salinity rose from 15 to 19 ppt, which was associated with photosynthetic activity and water evaporation under outdoor conditions. The total biomass yield reached 1,275 g (fresh weight) or 24.84 g (dry weight; DW.), with an average productivity of 0.81 g DW m^-2day^-1. Biochemical analysis revealed that the microalgal biomass contained chlorophyll a at 2.47 ± 0.03 mg g^-1 DW and total carotenoids at 1.90 ± 0.23 mg g^-1 DW. The protein content was 11.48 ± 0.95 mg g^-1 DW and carbohydrate content was 127.46±17.41 mg g^-1 DW. Additionally, total phenolic content was 5.29±0.02 mg gallic acid equivalent (GAE) g^-1DW, and total flavonoid content was 16.66±2.17 mg quercetin equivalent (QE) g^-1DW, indicating a high level of antioxidant potential. The results of this study indicate the feasibility of cultivating Tisochrysis sp. TISTR 11470 in outdoor systems. However, further investigations are required to optimize key cultivation parameters, such as light intensity, temperature, and nutrient composition, in order to enhance growth performance, ensure production consistency, and improve its potential for industrial-scale applications.

Development of a Business Data Question-Answering System Using Natural Language Based on Generative Artificial Intelligence

2026-04-09T15:13:57+07:00

Accessing business information for rapid decision-making today remains significantly hampered by specialized SQL language skills and the problem of hallucination in large-scale language models when working with complex database structures. This research aims to develop a natural language-to-database (NL2SQL) business information querying system and evaluate its technical performance by applying Retrieval-Augmented Generation (RAG) techniques combined with schema injection through the gpt-oss-120b generative AI model on a Groq LPU. The research process involved pilot testing using a standard Spider 1.0 dataset in the department store domain, consisting of 25 questions covering difficulty levels from easy to difficult. The results showed that the developed system performed significantly better than the basic query input method (zero-shot baseline), with an execution accuracy of up to 96.00% and an exact matching (EM) accuracy of 32.00%. Processing time efficiency was also assessed. The system has an average response time of only 0.73 seconds, which meets the human-computer interaction (HCI) benchmark of no more than 3 seconds. The results of this research confirm that integrating database architecture with generative artificial intelligence technology can effectively solve data hallucination problems and reduce communication latency, enabling general users and executives to access insightful data to support business decision-making accurately and quickly at a real-world level.

The Effect of Kale Powder Fortification on Color, Hardness and Sensory Acceptability of Jelly

2026-04-09T14:37:10+07:00

This research aimed to develop a jelly product supplemented with kale powder. The study investigated four levels of kale powder added to the jelly product: 0% (Control), 0.5%, 1%, and 1.5%. The results showed that the panelists gave the highest acceptance scores to the control formula. The Control formula obtained liking scores of 7.93±1.52 for appearance, 7.56±1.44 for color, 7.26±1.05 for aroma, 7.30±1.64 for taste, 7.26±1.48 for texture, and 7.06±1.92 for overall acceptance. However, since there was no statistically significant difference (p>0.05) between the control formula and the jelly product supplemented with 0.5% kale powder in terms of appearance, color, odor, taste, texture, and overall liking. Therefore, it can be concluded that the jelly product can be supplemented with up to 0.5% kale powder while still maintaining sensory acceptance from the panelists. When considering the results of the color values (L*, a* and b*), it was found that the jelly products supplemented with all four levels of kale powder were statistically significantly different (p≤0.05) due to the green color of kale powder. As the amount of kale powder increased the jelly product became darker green. Regarding texture (hardness), it was found that the control formula of the kale powder-supplemented jelly product was significantly different from the 5% kale powder-supplemented product (p<0.05). As the concentration of kale powder increased, the hardness of the jelly product markedly decreased. This might be because kale powder interfering with gel network structural of the jelly.

Optimal Allocation of Lifting Workload Using MILP Model under Time and Ergonomic Constraints

2026-05-18T11:21:46+07:00

This study aims to develop an optimal workload allocation model for manual lifting tasks by applying a Mixed Integer Linear Programming (MILP) framework under the Deterministic Allocation concept. The objective is to enhance operational efficiency while minimizing ergonomic risks in repetitive lifting activities. Experimental data were collected from ten volunteers in a controlled laboratory environment. Each participant performed repetitive lifting tasks of 10 kg objects, while video recordings were used to analyze time duration and postural behavior in each lifting phase. The ergonomic risk level was assessed using the Rapid Upper Limb Assessment (RULA) method. The results showed that the average lifting cycle time was 7.17 seconds, and the overall RULA scores indicated a moderate risk level. The MILP model was then applied to determine optimal workload allocation under three scenarios: (A) minimum total ergonomic load, (B) fair distribution, and (C) equal distribution. The findings revealed that scenario A achieved the lowest total risk but lacked fairness, while scenario B provided a balanced allocation between efficiency and equity. Scenario C demonstrated practicality for real applications requiring ease of management. Sensitivity analysis ±10% confirmed the model’s robustness and low sensitivity to parameter variations. Overall, the study highlights that MILP can serve as a quantitative decision-making framework for designing safe, ergonomic, and efficient lifting workload allocation policies.

Effect of Erythritol Substitution for Sucrose on Quality and Shelf Life of Coconut Candy under Modified Atmosphere Packaging

2026-04-09T14:37:51+07:00

This research aimed to investigate the basic formulation, production process, and to evaluate the sensory, chemical, physical, and microbiological qualities of coconut candy, including the partial replacement of sugar with erythritol. Sensory evaluation results indicated that the control formulation exhibited high overall acceptability in terms of aroma, taste, texture, and overall liking, with a mean score of 8.15. Among the erythritol-substituted formulations, the sample containing 30% erythritol replacement received the highest consumer acceptance for appearance, color, aroma, taste, texture, and overall liking, with a mean score of 8.59. Chemical and physical analyses revealed that the formulation with 30%erythritol replacement had the lowest moisture content (2.08%) and the highest ash content (0.86%). The formulation containing 30% erythritol replacement exhibited the highest fat, carbohydrate, and protein contents, at 11.32%, 82.99%, and 2.16%, respectively. Regarding color characteristics, the control formulation showed the highest lightness value (L*), while the formulation with 30% erythritol replacement presented the highest redness (a*) and yellowness (b*) values. Microbiological analysis demonstrated that coconut stored under 100% carbon dioxide modified atmosphere had the longest shelf life of 12 days, whereas vacuum-packed samples exhibited the shortest shelf life of 3 days. Total viable counts exceeded the acceptable limit on day 13 for carbon dioxide storage and on day 4 for vacuum storage. However, Staphylococcus aureus levels in all samples remained below 100 CFU/g, in accordance with the standards established by the Department of Medical Sciences.

Comparison of Fresh Fish and Formulated Diets on Growth Performance of Cobia (Rachycentron canadum) Cultured in Sea Cages in Ban Ko Pu, Krabi Province, Thailand

2026-05-15T18:25:42+07:00

This study aimed to compare the effects of fresh fish feed and commercial pellet diets on growth performance, survival rate, and feed utilization efficiency of cobia (Rachycentron canadum) cultured in marine cages at Ban Koh Pu, Krabi Province, Thailand. A Completely Randomized Design (CRD) consisting of three dietary treatments with three replicates per treatment was employed. Thirty fish were stocked in each cage and reared for 180 days. The results showed that the initial body weight of fish did not differ significantly among treatments (p>0.05). At the end of the experiment, fish fed the fresh fish feed exhibited the highest final body weight (2,023.16±22.62 g) and daily weight gain (8.01±0.13 g day⁻¹), which were significantly higher than those of fish fed the commercial pellet diets (p<0.05). Final body length differed significantly among treatments (p<0.05), whereas daily length gain showed no significant difference (p>0.05). Survival rates ranged from 91.12±2.65 to 93.34±2.31% and did not differ significantly among treatments (p>0.05). Similarly, feed conversion ratio (FCR) values ranged from 1.60±0.31 to 1.72±0.31, with no significant differences among treatments. Overall water quality remained within ranges suitable for marine cage culture of cobia throughout the study period. The findings indicate that fresh fish feed promoted better growth performance than the commercial pellet diets under the culture conditions of the present study. The results provide useful information for feed management strategies in community-based and commercial cobia cage farming operations.

A Robust Machine Learning Framework for Banana Damage Classification Using Image Processing Techniques for Smart Agricultural Quality Assessment

2026-05-15T17:52:26+07:00

Reliable banana quality assessment remains challenging due to the subjectivity of manual inspection. This study proposes a robust and evaluation-driven framework for banana damage classification that integrates image preprocessing, texture-based feature extraction, and multi-model learning strategies. A dataset of 568 banana images categorized into three damage levels was systematically processed to extract discriminative texture descriptors, reflecting surface variations and bruising patterns observed in practical conditions. To ensure statistical reliability, multiple training–validation–testing configurations were employed to evaluate model stability across varying data distributions. Five machine learning classifiers, namely Updateable Multiclass Classifier, Sequential Minimal Optimization (SMO), Multilayer Perceptron (MLP), Random Forest, and Iterative Classifier Optimizer, were evaluated to investigate the relationship between texture representation and classifier behavior. Comparative results demonstrate that adaptive classification models achieve superior performance, with the best model reaching 91.11% accuracy and an F1-score of 0.91, while maintaining consistent performance across experimental settings. Performance depends more on feature–model compatibility than model complexity. This work contributes a reproducible and practically applicable framework for intelligent quality assessment, supporting scalable deployment in smart agriculture and reducing post-harvest losses through data-driven decision-making. The proposed framework can support automated banana grading systems in post-harvest operations, reducing inspection subjectivity and enabling scalable deployment in smart agriculture environments.

Study of the Characteristics of Heat Rransmission in Spiral Pipes of Different Degrees

2026-05-22T15:01:29+07:00

Presently, there is an escalating research trend focused on renewable energy exploration and energy efficiency optimization. Rapid advancements in industrial technologies have concurrently led to a substantial increase in global energy consumption. Consequently, enhancing the performance of heat exchangers represents a viable strategy to mitigate energy consumption while simultaneously minimizing the physical size, weight, and installation footprint of the equipment. This study investigates the heat transfer characteristics and fluid flow behavior of hot water within twisted tubes configured at distinct angles. Experiments were conducted under a constant wall heat flux condition. The specific thermal transport characteristics were evaluated by adjusting the twist angles to 30, 60, and 90 degrees, utilizing volumetric flow rates of 20, 40, and 60 liters per minute at a constant temperature of 50 degrees Celsius. The experimental results indicate that turbulent flow occurs within the tubes when the Reynolds number exceeds 4,000 (Re > 4,000). Comparatively, the 30-degree twisted tube exhibited the highest heat transfer coefficient among all tested configurations, including the conventional smooth tube. Specifically, at flow rates of 20, 40, and 60 liters per minute the 30-degree twisted tube enhanced the convective heat transfer coefficient by 18.89%, 18.30%, and 18.83%, respectively, relative to the smooth tube.

The Design of Visual Communication Barriers and Decoding Perceptions for Standardizing Signage for Deaf Drivers in Thailand

2026-05-30T21:49:16+07:00

The primary objective of this study is to establish a standardized safety framework by evaluating behavioral intent and semantic transparency through a mixed-methods approach. Structuring the study into three systematic phases, a target sample was selected via purposive sampling from the national population of 391,371 registered deaf individuals. The experimental sample comprised 20 participants, bifurcated into two distinct groups: licensed deaf drivers (n = 10) and general motorists (n = 10). Empirical testing was executed using semi-structured interviews in conjunction with a Virtual Reality (VR) driving simulation experiment under dynamic environmental conditions to rigorously measure participants' cognitive latency and reaction times. Crucially, empirical findings reveal that current disability stickers fail as "active safety signals" due to poor chromatic contrast and a lack of ergonomic semiotic linkage. General motorists consistently fail to decode their meaning often perceiving outdated materials as visually obstructive while qualitative insights indicate that a subset of deaf drivers (80.0%, n = 8 out of 10) exhibit a profound psychological reluctance to display static identifiers due to fears of harassment and criminal targeting once their status is publicly marked. To address these systemic failures, the study proposes a standardized visual signaling framework based on ISO 7010 and Universal Design principles. By optimizing chromatic contrast and utilizing situational LED activation, this proposed active system aims to minimize perceptual latency, ensuring critical traffic safety information is decoded instantaneously without compromising the user’s anonymity.

A Solar Dryer Integrated with an Electric Heating System for Avocado Drying

2026-05-19T11:05:45+07:00

This research aims to design, develop, and evaluate the performance of a hybrid solar–electric dryer for drying local avocado varieties. The developed drying system operates by combining solar energy during the daytime with electrical energy when solar radiation is insufficient, enabling continuous drying for 24 hours. The experiment was conducted using 5 kg of avocados with an initial moisture content of approximately 84.7% (wet basis), under controlled drying temperatures of 60, 65, and 70 °C. The results showed that the drying system was able to maintain stable temperatures and achieve uniform heat distribution, resulting in a reduction of moisture content to approximately 10% (wet basis), with drying times of 24.1, 22.8, and 21.9 hours, respectively. Furthermore, the thermal efficiency of the system increased with higher drying temperatures, with values of 4.55%, 5.31% และ 5.65%, respectively, indicating that the temperature of 70 °C provided the highest efficiency. In conclusion, the developed hybrid solar–electric dryer effectively enhances drying performance, reduces drying time, and extends the shelf life of avocados and helps reduce post-harvest losses.

Effect of Al2O3 Particle Reinforcement on Mechanical and Thermal Properties of UHMWPE Composites

2026-06-18T08:52:36+07:00

Ultra-high molecular weight polyethylene (UHMWPE) is widely recognized for its excellent wear resistance, impact toughness, and chemical stability; however, its relatively low stiffness and thermal conductivity restrict its application in advanced engineering components. This study investigates the influence of micron-sized B-grade aluminum oxide (Al₂O₃) particles on the mechanical, thermal, chemical, and microstructural properties of UHMWPE composites. Composites containing 0–25 wt.% Al₂O₃ were fabricated through ultrasonic particle dispersion, high-speed powder homogenization, and hot compression molding. The materials were subsequently characterized using mechanical, thermal, spectroscopic, and microstructural analyses. The results demonstrated that Al₂O₃ reinforcement effectively enhanced the stiffness, hardness, breaking strength, and thermal conductivity of UHMWPE composites, while reducing elongation at break and impact resistance because the rigid ceramic particles restricted polymer-chain mobility. FTIR analysis confirmed that the molecular structure of UHMWPE remained unchanged after reinforcement, indicating that the improvement in properties originated primarily from physical interactions between the polymer matrix and ceramic particles. SEM observations further revealed effective particle dispersion and improved interfacial bonding at moderate filler contents, whereas localized particle agglomeration became more evident at higher loadings. The incorporation of ceramic particles significantly improved the thermal conductivity of the composites, demonstrating the effectiveness of ceramic reinforcement in enhancing heat-transfer capability. Overall, the findings confirm that controlled incorporation of Al₂O₃ particles provides a practical and efficient strategy for simultaneously enhancing the mechanical rigidity, thermal performance, and structural reliability of UHMWPE composites.