Journal of Science and Technology Phetchabun Rajabhat University

Stability analysis of switched positive nonlinear systems with a suitable switching law

2025-12-01T10:35:48+07:00

This paper examines the stability of switched positive nonlinear systems with all unstable subsystems. A discretized co-positive Lyapunov function, combined with a mode-dependent dwell time switching law, yields novel sufficient conditions for ensuring global uniform asymptotic stability for these systems. Comparison with prior work demonstrates greater generality, owing to both the systems' nonlinearity and the specific switching strategy. A numerical example supports the theoretical findings.

The Developing Knowledge of Educational Officer of Construction for Contract Management in the Fundamental Education Area in Phetchabun Province

2025-11-11T10:26:21+07:00

The applied research on "The Developing Knowledge of Educational Personnel in Construction Contract Management in Primary Educational Service Areas of Phetchabun Province," had two main objectives: 1) to survey the knowledge development needs and problems in construction management among higher education personnel in educational institutions, and 2) to develop and evaluate the effectiveness of a training curriculum. The basic data was collected through questionnaires and interviews with educational personnel in Primary Educational Service Areas of Phetchabun Province. The results of the needs assessment showed that, overall, personnel had a moderate need for knowledge development, with an average score of 3.36% out of a possible 5 evaluation criteria across 3 areas and 9 items. This indicates the necessity for developing specialized knowledge. The collected data was used to design and develop a training curriculum in construction contract management. This research piloted the curriculum with a group of 50 educational personnel. The effectiveness evaluation (E1) of learning units 1, 2, and 3 was 85.36%, 85.68%, and 85.84%, respectively. The overall curriculum effectiveness (E1/E2) was 85.63%/85.84%, exceeding the set criteria of 80%/80%, demonstrating the high efficiency of the developed curriculum and its ability to effectively transfer knowledge.

Furthermore, participant satisfaction was high, particularly regarding knowledge, understanding, and practical application, which had the highest average score of 4.39. the satisfaction with the instructors had an average score of 4.17, and satisfaction with the venue/time/food had an average score of 3.47.

Performance of supercapacitor electrodes made from corn cob-derived activated carbon

2025-12-29T09:44:45+07:00

Corn is a significant economic crop in the country, utilized for consumption and in the food production industry. The residual byproduct, corn cobs, can be synthesized into highly porous carbon, which can then be fabricated into electrodes for supercapacitors. In this research, the performance of the supercapacitors was enhanced by incorporating carbon black (CB) in ratios of 1:4, 2:3, and 1:1. The mixtures were ball-milled for 24 hours and subsequently coated as carbon films onto aluminum foil using a spray technique. This process yielded both pure corn cob-derived carbon electrodes and those mixed with carbon black. Surface morphology of the resulting carbon films was examined using Scanning Electron Microscopy (SEM). The results indicated that the carbon black nanoparticles were intercalated into the surface of the corn cob-derived carbon. Fourier-Transform Infrared Spectroscopy (FT-IR) analysis was conducted to investigate the functional groups of the electrodes; the 2:3 ratio exhibited the highest absorption values at the O-H stretch and C-N stretch bonds. Finally, the materials were assembled into coin-cell supercapacitors. It was found that the corn cob-derived carbon supercapacitors could achieve a 2.7-fold increase in efficiency with the addition of carbon black. Therefore, this material is suitable for fabrication into supercapacitors to be utilized as an energy storage source.

The Development of a Prototype Gas Stove Safety System for Residential Buildings Using Embedded Systems Technology

2026-02-25T15:25:38+07:00

The objectives of this research were to 1) develop a prototype safety system for household gas stoves using an embedded system technology, 2) evaluate the efficiency of the prototype system, and 3) assess user satisfaction with the prototype system. The prototype system consists of two main components: a main control unit and a gas leakage detection unit. The system operates in both automatic and user-controlled modes, with functions including scheduled operation and on/off control and visual and audible notification system. The prototype is developed using an Arduino Uno R3 board, an MQ-6 gas sensor, a gas solenoid valve, a keypad, an LCD display, an audible and LED notification. System performance evaluation includes unit testing with four functions and system testing with four functions, as well as a study of user satisfaction with the prototype system. The statistical methods used for data analysis included mean, percentage, and standard deviation. The results showed that the efficiency of the prototype based on unit testing achieved 100% on all 4 functions which are gas dispersion over the distance, automatic gas shutoff, automatic operation scheduling, and gas concentration alert notification at 400 ppm. Similarly, the system testing results also demonstrated 100% efficiency on all 4 functions which were gas dispersion over distance, automatic gas shutoff, automatic operation scheduling, and gas concentration alert notification at 400 ppm. Furthermore, user satisfaction rate of the prototype system was at the highest level, with an average score of 4.57 and a standard deviation of 0.52

The production of briquetted biochar to meet market demand

2026-02-24T11:00:25+07:00

This study aims to evaluate the physical characteristics, combustion performance, thermal properties, and economic feasibility of briquetted biochar produced by two community enterprises (BS and JJ), in comparison with five commercially available briquetted biochar samples collected from local markets in Phan and Mueang Districts, Chiang Rai Province. The evaluation was conducted in accordance with the Community Product Standard for briquetted biochar (TISI 238/2547).
The results revealed that all samples exhibited higher heating values (HHVs) exceeding 20.93 MJ/kg. The HHVs of samples BS and JJ were 24.10 ± 0.08 and 22.15 ± 0.20 MJ/kg, respectively. However, the moisture contents of the community-produced briquettes were higher than those of several commercial samples, which affected combustion quality. In particular, sample JJ showed higher smoke emissions, indicating a need for further improvement in the production process. Economic analysis indicated that the initial investment ranged from 45,000 to 70,000 THB, with a production capacity of approximately 100 kg per day and a suitable selling price of 15–20 THB/kg. The estimated payback period was 7–8 months. Overall, the findings demonstrate the potential for improving the quality and market competitiveness of community-based briquetted biochar, supporting sustainable local economic development.

An Examination Management System for the Faculty of Science and Technology

2026-02-26T11:18:37+07:00

This research aimed (1) to develop an examination management system for the Faculty of Science and Technology and (2) to investigate user satisfaction with the developed system. The study addressed limitations in existing examination administration processes that relied on paper-based documents and general office software, resulting in data redundancy, delays in examination scheduling and verification, insufficient traceability of examination procedures, and increased risks of data management errors. The proposed system was developed as a web-based application using HTML, PHP, CSS, JavaScript, jQuery, and SQL, and was integrated with notification services via the LINE Messaging API. The system supports comprehensive examination management processes, including course and stakeholder management, examination scheduling, data storage and retrieval, process status tracking, automated notifications, and summary report generation, with the aim of enhancing efficiency, accuracy, and transparency in examination administration.

The system evaluation utilized user satisfaction surveys, analyzed through descriptive statistics specifically mean and standard deviation from a purposive sample. The assessment covered four key areas: system requirements, system functionality, system usability, and system security. The results indicated the highest level of satisfaction across all dimensions. Specifically, system requirements achieved a mean of 4.68 (SD = 0.47), system functionality 4.61 (SD = 0.49), system usability 4.64 (SD = 0.46), and system security 4.62 (SD = 0.49). With an overall mean of 4.63 (SD = 0.47), these findings demonstrate that the system effectively meets practical operational needs and efficiently supports examination management.