Journal of Engineering and Industrial Technology, Kalasin University

Adaptive Transmission Strategies for Energy-Efficient Long-Term Outdoor IoT Monitoring

Jaratpong Tepmanee — 2026-06-29

Continuous high-resolution data transmission in Internet of Things (IoT)-based environmental monitoring systems leads to significant communication overhead and energy consumption, particularly in long-term outdoor deployments. This study aims to evaluate and compare energy-efficient data transmission strategies for long-term outdoor IoT environmental monitoring systems under real-world conditions. A system-level evaluation was conducted using a real-world environmental sensing platform deployed in Chiang Rai, Thailand. The system, built on an ESP32 microcontroller with SHT20 and PMS3003 sensors, collected temperature, humidity, and PM2.5 data at 30-second intervals from March 2024 to May 2025, resulting in 1,048,406 transmission events under the baseline configuration. Two transmission reduction strategies were evaluated: fixed downsampling and adaptive sampling based on signal variability. Performance was assessed using Data Reduction Ratio (DRR) and Event Preservation Ratio (EPR), including both PM-only and multi-parameter event detection. The fixed downsampling approach achieved the highest data reduction (90.00%) but preserved only 15.91% of multi-parameter environmental events. In contrast, adaptive sampling reduced transmission by 78.89% while preserving 56.76% of combined environmental events. The results demonstrate that maximizing transmission reduction alone is not suitable for dynamic environmental monitoring. Variability-aware adaptive transmission provides a more balanced trade-off between energy efficiency and event preservation. This study proposes a practical evaluation framework for designing energy-constrained IoT monitoring systems under real long-term outdoor conditions.

Design and Development of a 4 Row Mechanical Rice Transplanter

Siripong Treerat — 2026-06-29

This research aims to design, develop, and evaluate the performance of a 4-row mechanical rice transplanter to address labor shortages and reduce production costs for small farmers. The primary components include a power transmission system a four-bar linkage planting mechanism and a seedling supporting hook. Field performance was tested by varying the inclination angles of the seedling hook at 40, 45, 50 and 55 degrees. The results indicated that the 50-degree angle achieved the optimum performance with a minimum missing hill rate of 8%. The average planting depth ranged from 3 to 5 cm with an average of 3.86 seedlings per hill. The machine demonstrated a field capacity of 0.25 rai/hr and a field efficiency of 92%. Economic analysis showed that the prototype cost 5,000 THB to construct and reduced production costs by 700 THB per rai compared to manual transplanting, the break-even point at 1.76 rai per year. This mechanical rice transplanter proves to be a cost effective and viable solution for small rice farming.

Development of Composite Material from Sedge Mat Weaving Waste for Environmentally Friendly Packaging Design

Samart Chanthana — 2026-06-29

This research aimed to develop a bio-based material from sedge waste generated during the traditional mat-weaving process in Chanthaburi Province, Thailand, to create environmentally friendly packaging prototypes under the concept of a circular economy. The study integrated material science and eco-design approaches in both material formulation and product design. The sedge waste was ground and blended with cassava starch, starchy water, vegetable oil, and beeswax to enhance tensile strength, flexibility, and water resistance. The mixture was molded into bioplastic sheets and dried using solar energy. The mechanical tests showed an average tensile strength of 3.2 MPa, 85% recovery after bending, and over 80% biodegradation within eight months. In the design stage, the developed material was applied to create eco-friendly packaging prototypes such as souvenir boxes and display trays, emphasizing sustainable aesthetics and green communication. The evaluation using Quality Function Deployment (QFD) indicated high satisfaction in terms of safety, natural appearance, and environmental friendliness. The study demonstrates the integration of scientific experimentation and creative design to transform local waste into sustainable bio-materials, supporting community-based production and promoting circular economy development.

Thermal Efficiency Enhancement in Solar Collectors Using Porous Duct Absorbers for a Solar Dryer

Suradech Sinjapo — 2026-06-29

The objective of this research was to investigate the influence of porous media on the thermal efficiency of solar collectors using porous duct absorbers. The experiments were conducted under two configurations: 1) a flat-plate solar collector and 2) a collector equipped with porous duct absorbers. SUS 304 stainless steel wire mesh was used as the porous medium. Four pore densities of 12, 16, 20, and 24 pores per inch (PPI) were examined. The height ratio and pitch ratio were fixed at 1 and 2, respectively. The incident solar radiation intensities were set at 600, 800, and 1,000 W/m². Three mass flow rates of air consisting of 0.010, 0.015 and 0.020 kg/s were investigated. The experimental results revealed that the collector integrated with porous duct absorbers exhibited significantly higher thermal efficiency than the flat-plate collector under all operating conditions. Thermal efficiency increased with increasing air mass flow rate due to enhanced convective heat transfer. The maximum thermal efficiency of 54.96% was achieved at PPI = 12 and an air mass flow rate of 0.02 kg/s and an incident radiation intensity of 1,000 W/m². In addition, the porous duct absorbers effectively reduced the moisture content of the dried product. These findings indicate that porous duct absorbers have strong potential for improving solar drying systems and low-temperature heat exchange applications.

Pumpkin Slices Using Heat Pump Dryer for Farmers

Teerasad Kanasri — 2026-06-29

This research aimed to investigate the use of a heat pump drying system powered by a 5.5 kW electric compressor and a 7.8 kW heating coil. The system delivered an air flow rate of 12,800 –23,600 m³/h within a drying chamber sized 200×400×200 cm (W×L×H). The dryer structure included a drying chamber, product trays, and a heat pump system integrated with an electric heating coil. The maximum controllable drying temperature was 75 °C. Drying experiments of 300 kg were conducted using sliced pumpkin, evaluating parameters such as energy consumption, drying time, moisture content, water evaporation rate, and color quality of the dried product. The system efficiently transferred heat from the evaporator to the condenser using compressor energy, while also removing moisture from the chamber without requiring external ventilation. This allowed for stable drying conditions independent of ambient temperature drying at 60 °C effectively reduced moisture content in thin pumpkin slices to the required standard within 7 hours. The energy consumption was recorded at 85.16 kWh, with a specific energy consumption of 1.51 MJ/kg of evaporated water.

A Hybrid Dynamic Thermal Modeling Approach for Tank Temperature Estimation of a 25-MVA ONAF Power Transformer

Dumrongsak Wongta — 2026-06-29

This research presents the development of a hybrid dynamic thermal model for estimating the tank temperature of a 25 MVA power transformer equipped with an Oil Natural Air Forced (ONAF) cooling system. The primary objective is to enhance the accuracy of temperature prediction under time-varying load conditions. The proposed model integrates the principles of steady-state thermal modeling and dynamic thermal modeling, enabling the simultaneous determination of both the final steady-state temperature and the transient thermal response. In the simulation, the ambient temperature was assumed constant at 28 °C, and the computation was performed at 15-minute intervals over a 24-hour period, yielding a total of 96 data points. The load current was varied within a range of 0.3 to 1.8 per unit (p.u.). The comparative results indicate that the hybrid dynamic thermal model more accurately captures the temperature variation trends in accordance with actual operating behavior than either the steady-state or conventional dynamic thermal model. Furthermore, the model performance was validated against the Finite Element Method (FEM). The evaluation was conducted across three load levels conditions: low, medium, and high, with copper losses ranging from 0 to 57.39 kW, consistent with the transformer’s rated loss specifications. The mean absolute percentage error (MAPE) for the steady-state model was found to be 6%, 8%, and 10% for low, medium, and high load conditions, respectively. In comparison, the dynamic thermal model yielded MAPE values of 1.80%, 2.57%, and 3.31%, while the hybrid dynamic thermal model achieved lower errors of 1.24%, 0.66%, and 2.35%, respectively. The results demonstrate that the hybrid dynamic thermal model provides the lowest average temperature estimation error among the considered approaches. This confirms that the proposed model achieves an acceptable level of engineering accuracy and shows strong potential for practical applications in load analysis and real-time transformer temperature monitoring systems.

Optimal Design of a Prototype Sugarcane Harvester Using the Finite Element Method

Khanthamat Choodoungkaittikul — 2026-06-29

This research aims to develop a prototype of a whole-stalk sugarcane harvester by applying reverse engineering in combination with three-dimensional design and analysis using the Finite Element Method (FEM) to propose structural improvements prior to actual fabrication. Data from the existing prototype were utilized to create a three-dimensional model and to evaluate structural strength. The sugarcane topper cutting unit was designed to enable more continuous operation, to reduce the accumulation of debris within the working area. The structural analysis results indicated that the original sugarcane topping system had a yield strength of 2.83×10⁸ Pa and a maximum Von Mises stress of 2.67×10⁸ Pa, resulting in a factor of safety (FoS) of 1.06, which is close to the yielding condition of the material. After structural improvement, the maximum Von Mises stress was reduced to 140.50 MPa, and the FoS increased to approximately 2.01, demonstrating an improvement in structural safety and an enhanced capability to withstand fluctuating loading conditions in actual operation. In addition, the concept of a leaf-clearing mechanism helps reduce clogging caused by the accumulation of sugarcane leaves, resulting in a more continuous and efficient harvesting process.