Rattanakosin Journal of Science and Technology

Assessment of The Working Posture Risks of Material Handling Employees: A Case Study of Food Production Company

Maninthara Chaikhampan — 2026-08-31

This research article aims to study the working postures of material handling employees and to propose guidelines for reducing ergonomic risk factors. The research methodology involved purposive sampling for data collection with a case study of 6 material handling employees from a food production company. The Abnormal Index and Rapid Upper Limb Assessment (RULA) were used for evaluation. The research findings showed that 3 employees had an abnormal Index score of 3 or higher. The RULA score after improvement was 5, which is level 3, compared to the pre-improvement score of 7, which is level 4. The factors that led to a decrease in the RULA score were the use of tools and equipment to assist in lifting boxes onto the conveyor belt for stacking on pallets.

Influence of Recycled Asphalt Concrete Pavement Gradation on CBR of Mixed Materials

Piyachat Chattonjai — 2026-08-31

Due to its inherently low compactibility, Reclaimed Asphalt Pavement (RAP) cannot be directly used as a landfill material for road structures without improving its engineering properties. One simple and economical method to enhance RAP is by adding RAP with soil to improve the gradation without the addition of cementitious materials. However, the gradation of RAP, which is a by-product of
the removal process of old asphalt concrete pavements, varies depending on the penetration speed during the milling process. Therefore, it is important that construction planning considers not only the economic benefits, but also the impact of RAP gradation on the bearing capacity of the mixed materials. In this research, the different gradations of RAP were mixed with lateritic soil and crushed rock at various weight ratio. The mixed materials were compacted and tested using California Bearing Ratio (CBR) to investigate the influence of RAP gradation on bearing capacity. Based on the test results, the CBR value increased with the amount of both types of soil added. However, the maximum CBR value of the mixed material was not governed by the gradation of RAP, but controlled by the CBR of the mixed soil, which is equal to the CBR of mixed soil at the maxing ratio of optimal mix proportion point and will constant after beyond this point. Coarse-grained RAP not only offers greater cost benefits compared to fine-grained RAP, but also provides better bearing capacity at the same mixing ratio.

Home Visit Information System for Student Behavior Management

Krit Chaiwannakoop — 2026-08-31

Home visits are essential for supporting student behavior and school–family collaboration. However, current practices lack an integrated system that combines behavioral and spatial data.This study aimed to develop a web-based Home Visit Information System using a relational database and the Google Maps API to record student home coordinates and support navigation for home visits
in real settings. The system supports four user roles—administrators, teachers, students, and system managers—and provides key functions including visit record management, behavioral assessment, attachment of evidence, and statistical reporting. The system was developed following the System Development Life Cycle (SDLC) and evaluated using a mixed-methods research design through questionnaires and in-depth interviews. The evaluation results indicated good to very good efficiency (𝑥̄ = 4.48, S.D. = 0.56), particularly in functionality and security. Users expressed satisfaction with its convenience and accuracy, emphasizing its ability to reduce paperwork, enhance transparency, and support administrative decision-making. The findings highlight progress in integrating behavioral data with spatial information and demonstrate the potential for extension to other educational information systems, such as guidance, student support, and policy analysis systems. This advancement contributes to proactive educational management at both the school and district levels.

An experiment to measure local gravity using a cylindrical rod pendulum by the classical method

Bancha Kongtragool — 2026-08-31

Engineering calculations that require gravitational values for precise and sensitive results must always consider the local gravitational acceleration. In this paper, the results of determining local gravity using a rod pendulum as a gravimeter are presented. The study was conducted at a location with a latitude of 18°39'43" N and an elevation of 300 meters above mean sea level (MSL). The studying used rod pendulums with varying free lengths of 60, 120, 180, 240, and 300 mm. The time for 100 oscillations of the pendulum was measured and repeated 12 times. The experimental results showed a local gravitational acceleration of 9.789 ± 0.001 m/s². When compared with the calculated local gravity value of 9.7847 m/s², the error was approximately 0.04%

Growth Response of Bacopa monnieri (L.) Wettst. to Different Dilution Ratios of Organic Composting Leachate

Apichaya Phadpin — 2026-08-31

The study investigated the optimum proportion of leachate solution for the soilless cultivation of Bacopa monnieri (L.) Wettst. derived from the composting of discarded vegetable waste from Kamphaeng Phet fresh market in Kamphaeng Phet province, Thailand. The composting process relied on microbial activity in soil to decompose raw materials and convert them into essential nutrients. Leachate samples were collected after 0, 7, 14, and 21 days of composting and subsequently diluted with sterile water at ratios of 1:1, 1:5, 1:10, 1:50, and 1:100 (leachate: sterile water) to formulate different nutrient solutions. Bacopa monnieri (L.) Wettst. was cultivated soilless in a greenhouse, with treatments arranged in a completely randomized design, and grown until post-harvest (42 days). Results indicated that the 14-day leachate solution at a 1:10 ratio significantly promoted plant height and leaf length (P<0.05), measuring 22.40 cm and 1.00 cm, respectively. Furthermore, the 21-day leachate solution treatment yielded the highest (P<0.05) average number of leaves, with a value of 18.3, compared to other treatments. These findings confirm that leachate derived from composting organic waste, particularly the 14-day fermentation leachate diluted at a 1:10 ratio, possesses the potential to serve as a valuable substitute for chemical fertilizers, providing a necessary nutrient source for plant growth. Furthermore, it serves as a waste management strategy that adds value to vegetable scraps and reduces reliance on chemical fertilizers in urban farming systems moving forward

Facial recognition system for borrowing equipment

Mallika Chatchawankitkun — 2026-08-31

This project proposes the development of a smart borrowing and returning cabinet system using Raspberry Pi integrated with infrared sensor and a facial recognition system. The system designs to identify the users through facial recognition before granting access to borrow or return equipment. The cabinet operation has simple two states: when the user’s face successfully verified the cabinet unlocks; otherwise, the access is denied. The cabinet shows the status through the LED, if there is an equipment in the cabinet, the light will be on. But if there is no equipment, the light will be off. All borrowing and returning activities are logged in a .txt file to recording the student ID, date, and time. The face recognition methodology is recognizing the user faces without any face covering like hats, glasses, masks, etc. and record in database as reference. The evaluates from 3 volunteers. The results show all samples the face recognition system can be verified when users no face covering. In case of wearing sunglasses, hats or masks or have some covering the face, the system will lower performance. In addition, if another person who does not store information, the system cannot verify as designed.

On the Solutions of Two Egyptian Fractional Equations

Suton Tadee — 2026-08-31

In this research, we have studied all positive integer solutions of two Egyptian fractional equations and . The results showed that the Egyptian fractional equation has twelve positive integer solutions, which are and . The Egyptian fractional equation , where is a prime number and is a positive integer, has all positive integer solutions , which are in the form , where is an integer with and is a positive integer with .

Comparative Evaluation of Antioxidant Potential and Basic Chemical Properties of Thai Honeys from Four Floral Sources

Warawaran Shimbhanao — 2026-08-31

This study aimed to investigate the antioxidant activities and chemical compositions of honeys derived from four floral sources: coffee, lychee, longan, and Siam weed. Honey samples were collected from commercial honey producers in Chiang Mai Thailand. The antioxidant activities were evaluated using FRAP and DPPH assays, while total phenolic content and chemical compositions, including total soluble solids (°Brix), total acidity, and pH, were also analyzed. The results showed that coffee flower honey exhibited the highest antioxidant capacity, with FRAP and DPPH inhibition values of 36.33±2.01 µmol mg GAE/100 g honey and 39.53±0.76%, respectively, along with a total phenolic content of 49.91±1.88 mg GAE/100 g honey. Lychee and longan honeys demonstrated similar moderate levels of antioxidant activity, whereas Siam weed honey showed the lowest values across all antioxidant parameters. In terms of chemical composition, coffee flower honey had the highest °Brix value (81.03±0.49°Brix), while lychee honey exhibited the highest total acidity (2.09±1.33 mEq/100 g honey) and the lowest pH (3.38±0.06). Siam weed honey presented the lowest total soluble solids and total phenolic content values, corresponding with its weak antioxidant properties. These findings indicate that coffee flower honey has the highest potential as a biologically valuable ingredient suitable for development into natural health supplements or beauty products. Lychee and longan honeys also demonstrated promising chemical and biological properties. This study provides essential baseline data for selecting high-value Thai honeys and for adding commercial value through product innovation.