Journal of Engineering and Industrial Technology, Kalasin University

Effect of Mixing on Biogas Production Rate in a Two-Stage Digester

Phongphan Promphiphak, Phongsagorn Chidchob, Sukarin Khamsuwan — Tue, 28 Apr 2026 00:00:00 +0700

This study demonstrates the effect of stirring on the biogas production rate from cassava pulp under anaerobic conditions using a two-stage digester system which is operated in the mesophilic temperature range (35 °C). Immersion heaters were installed to control the temperature in both the acidogenic and methanogenic digesters, and the initial pH was adjusted to 8. The two-stage digestion system consisted of one acidogenic digester with a working volume of 250 liters, two methanogenic digesters with working volumes of 500 liters each, and one gas storage tank, all tanks are connected in series. The system was operated under batch feeding conditions using organic substrate prepared by mixing cassava pulp with water. The hydraulic retention time was set at 12 hours, and the total solids concentration of the solution was maintained at 20% (w/v), corresponding to an organic loading rate of 0.417 g COD L^-1day^-1. The stirring frequency was varied from no stirring to intermittent stirring at frequencies of 12, 8, 4, and 2 hours per cycle, with a stirring duration of 10 min per cycle. The results showed that the average biogas production rates were 140, 160, 190, 240, and 280 L day^-1, respectively. The average electrical energy consumption for stirring was 0, 373, 1,119, 2,238, and 4,470 Wh day^-1, respectively. The average net energy outputs were 898, 654, 100, −697, and −2,672 Wh day^-1, respectively.

Development of Photovoltaic–Thermal Porous Solar Dryer

Tue, 28 Apr 2026 00:00:00 +0700

Drying is a key post-harvest process for preserving agricultural and herbal products. However, under humid tropical conditions, drying remains energy-intensive and limited in performance. This study presents the development and performance evaluation of a photovoltaic–thermal (PVT) solar dryer integrated with porous absorbers to enhance heat and mass transfer. The system consists of a 150 W PVT panel and a solar air collector equipped with porous steel mesh absorbers with porosities of 0.98 and 0.96, together with a non-porous reference configuration. Drying experiments were conducted in Thailand under tropical conditions at an air velocity of 0.1 m/s using kaffir lime leaves. The results show that porous integration increases the effective heat transfer area and thermal energy retention, resulting in a drying rate increase of up to 50% and a reduction in specific energy consumption (SEC) of up to 33.3% compared with the non-porous system. The configuration with a porosity of 0.96 provided the best overall performance. Overall, integrating porous materials into a PVT solar dryer significantly improves drying performance and energy efficiency.

Development of a Progressive Web Apps with Artificial Intelligence for Rice Leaf Disease Classification

Piyapong Dangkham, Wadeenat Wannasawaskul — Tue, 28 Apr 2026 00:00:00 +0700

This research presents the development of RiceCare PWA, an application for classifying rice leaf diseases using Artificial Intelligence (AI) integrated with Progressive Web Apps (PWA) technology. The system is designed to provide farmers with a convenient and rapid tool for analyzing diseases from leaf images, even in areas with limited internet connectivity. The AI model was trained on a 6-class dataset from the rice leaf disease dataset using the Google Teachable Machine platform. The model's performance was evaluated through eight statistical metrics: precision, recall, F1-score, specificity, NPV, FPR, FNR, and MCC. The results demonstrate high classification accuracy, with precision values ranging from 0.70 to 0.78, recall between 0.72 and 0.82, and MCC between 0.65 and 0.76, reflecting strong stability and correlation between predictions and actual ground truth data. By leveraging PWA technology, ricecare enables offline processing, which is crucial for field operations in remote areas. System testing across six Android smartphone models revealed an average image processing time of only 1.46 seconds and a high operational success rate of 99.4%, with only minor initial latency during the first-time model download. Field testing on 200 rice leaf images showed a 90.5% agreement rate between the application's results and expert farmers' assessments, with nearly 100% accuracy in identifying healthy leaves. Furthermore, a user satisfaction survey with 10 participants yielded an excellent rating of 4.65. These findings confirm that RiceCare PWA is an effective tool for rice disease detection, reducing diagnostic time, increasing accuracy, and serving as a sustainable framework for applying AI and PWA in community-level smart agriculture.

An Integrated IoT-Based System for Vital Sign Monitoring and Patient Identification for Smart Hospitals

Pattaya Tammaboot, Ekkachai Naenudorn — Tue, 28 Apr 2026 00:00:00 +0700

This study aimed to develop an intelligent system for vital-sign monitoring and patient identification using Internet of Things (IoT) technology. The proposed system integrates multiple sensors to measure vital signs and employs a QR code embedded on a wristband to verify patient identity, thereby reducing the risk of misidentification and enhancing patient safety. The system is also connected to the Hospital Information System (HIS) to enable real-time recording of vital-sign data, allowing healthcare personnel to monitor patient conditions and assess disease severity promptly, thus improving the efficiency and quality of clinical care. System usability was evaluated using the System Usability Scale (SUS), and the obtained score was close to the general benchmark. In addition, system performance in terms of Quality of Service (QoS) was assessed, covering key indicators including availability (88.33%), accuracy (73–89%), and system stability (65.75%). The findings indicate that the proposed system can reduce healthcare workers’ workload and minimize redundant documentation, which may otherwise lead to errors and delays. The device automatically measures three essentials vital signs blood pressure, blood oxygen saturation, and body temperature—and transmits the data directly to the hospital database, enabling medical staff to access accurate and up-to-date information for effective clinical decision-making. Therefore, the system serves as an important component in supporting the Smart Hospital initiative in accordance with the policy of the Ministry of Public Health.

A Comparative Study of Energy Consumptions per Passenger between Hitachi Series 1000 EMU and Hitachi Series 2000 EMU for the State Railway of Thailand Northern Red Line

Tue, 28 Apr 2026 00:00:00 +0700

This study compares the electrical energy consumption per passenger-kilometer (kWh/pass-km) and per car-kilometer (kWh/car-km) of the Northern Red Line electric train service between Krungthep Apiwat Central Station (KTW) and Rangsit Station (RST), focusing on two train types: the Hitachi Series 1000 (6 car) and the Hitachi Series 2000 (4 car). Energy consumption data were obtained from the SCADA system, while passenger volume data were collected from the OD Matrix of the AFC system during October 2023. The analysis revealed that the Series 1000 consumed more energy per passenger-kilometer (0.2179–0.2411 kWh/pass-km) compared to the Series 2000 (0.1547–0.1749 kWh/pass-km), and also exhibited higher energy consumption per car-kilometer (4.5933 versus 3.3335 kWh/car-km), reflecting differences in energy efficiency between the two train types. The findings have significant implications for railway operations: train selection should be aligned with passenger demand, with Series 2000 offering greater efficiency during low-demand periods; flexible scheduling that deploys Series 2000 during off-peak hours and Series 1000 during peak hours can balance energy efficiency with passenger capacity; long-term energy cost assessments can benefit from the observed differences in energy consumption per passenger-kilometer, particularly in scenarios of route expansion or increased service frequency; and empirical evidence from this study can support future procurement or retrofitting decisions to enhance energy efficiency, especially when expanding the system or increasing fleet size.

Development and Production of Solid Nonloadbearing Concrete Masonry Units Using Corn Stalks-Based Materials

Tue, 28 Apr 2026 00:00:00 +0700

This study aims to investigate the feasibility of utilizing agricultural waste, specifically the inner core of corn stalks, as a partial replacement of conventional aggregates in concrete block production. The research focuses on analyzing the effects of replacing natural aggregates with corn core at proportions of 15%, 20%, and 25% by volume on the physical and mechanical properties of concrete blocks. Experimental evaluations included density and compressive strength tests to assess the suitability of the developed material for non-load-bearing wall applications. The results indicate that increasing the corn core content in the mixture leads to a continuous reduction in density, decreasing from 2,453.4 kg/m³ at 15% replacement to 2,243.8 kg/m³ at 25% replacement. Similarly, compressive strength declined from 24.274 MPa at 15% replacement to 15.848 MPa at 25% replacement. This trend suggests that a higher proportion of corn core increases the internal porosity of the concrete matrix, resulting in reduced unit weight and compressive capacity. Nevertheless, the compressive strength values at all replacement levels remained within an acceptable range for non-load-bearing wall applications. Considering the balance between weight reduction and mechanical performance, a replacement ratio not exceeding 20% was found to provide the most suitable outcome. At this proportion, the concrete blocks maintained adequate structural integrity while achieving a meaningful reduction in density. The findings demonstrate the potential of corn core as an alternative aggregate component in concrete block manufacturing and highlight its applicability as a locally available agricultural resource for producing lightweight construction materials suitable for practical implementation.

Design and Development of a Web-Based Geoinformatics System Integrated with QR Code for Cultural Tourism in Pa Tan Subdistrict, Lopburi Province

Yanapat Lappanitchyakul, Duangthip Rubporndee — Tue, 28 Apr 2026 00:00:00 +0700

This research aims to design and develop a web-based geoinformatics system integrated with QR code technology for cultural tourism in Pa Tan Subdistrict, Lopburi Province. The system is intended to support the management and accessibility of spatial data within the context of cultural tourism. The system was developed under a client–server architecture, emphasizing the integration of spatial data with on-site information access through QR code technology. The system was evaluated in a real-world environment using a sample of 210 participants, including local residents, tourists, and general users. The research instrument was a five-level Likert scale questionnaire for user satisfaction. The data were analyzed using descriptive statistics, including mean and standard deviation. The results showed that the system functioned according to the design specifications. Users reported satisfaction at a good level in all aspects, with an overall mean score of 3.94 and a standard deviation of 0.69, these findings indicate that the system effectively supports access to spatial information in real-world tourism contexts. Furthermore, the system demonstrates an approach to integrating spatial and cultural data with community participation, promoting continuous usage and sustainability at the local level.