https://ph02.tci-thaijo.org/index.php/RJST/issue/feed Rattanakosin Journal of Science and Technology 2026-08-31T10:31:32+07:00 รศ.ดร.พิชิต กิตติสุวรรณ์/Assoc.Prof.Dr.Pichid Kittisuwan rjst@rmutr.ac.th Open Journal Systems <p>The Rattanakosin journal of science and technology (RJST) is the peer-reviewe and open-access journal that disseminates novel research works about science and technology. At present, three peer reviewers in each research topic from various institutes based on the blind peer review technique are used to review each manuscript. Moreover, all authors and peer reviewers belong to different institutes.</p> <p>RJST is a forum through which scientists and experts in the fields of science and technology share and discuss their quality research. Original research articles, as well as review articles and brief papers in multidisciplinary scientific and technological fields are included in the journal. </p> <p>Welcome article submissions from all science and technology research areas including Physics, Chemistry, Biology, Mathematics, Statistics, Computational, Food Science Technology, Engineering, Architecture and Educational Science, ect.</p> <p>Rattanakosin Journal of Science and Technology is published 3 issues a year: Issue1 (January-April), Issue 2 (May-August) and Issue 3 (September-December).</p> <p> </p> <p><strong>Aims and Scope:</strong></p> <p>The journal aims to provide a platform for researchers, scientists, academicians and students to share knowledge and ideas in the form of high quality articles covering the main fields of science and technology including Physics, Chemistry, Biology, Mathematics, Statistics, Computational, Food Science Technology, Engineering, Architecture and Educational Science, ect.</p> <p><strong>Editorial Policy:</strong></p> <p>Papers, comprising review articles and research paper, will be judged for publication on the basis of evaluation by independent reviewers. Such articles include substantial supported theories, innovative work, substantial experimental results, useful and constructive discussion, and review articles in the fields of of science and technology including Physics, Chemistry, Biology, Mathematics, Statistics, Computational, Food Science Technology, Engineering, Architecture and Educational Science, ect. An electronic journal is provided on the website (https://www.tci-thaijo.org/index.php/RJST/index). The Editors reserve the right to require revision of the submitted manuscript as a condition for final acceptance.</p> <p>The institute and the editorial board claim no responsibility for the contents or views expressed by the authors of individual articles. Copying is allowed provided that acknowledgement is made. All articles submitted for publication will be assessed by a group of distinguished reviewers.</p> <p><strong>Open Access Policy:</strong></p> <p>This journal provides open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge and ideas.</p> <p><strong>Journal Abbreviation</strong>: RJST<br /><strong>e-ISSN</strong>: 2673-0553 (Online)</p> <p><strong>Starting Year</strong>: 2019<br /><strong>Language</strong>: English and Thai<br /><strong>Publication Fee</strong>: No Page Charge (Free). All articles can be freely downloaded from the journal website.<br /><strong>Publication Date:</strong> Each volume comprises three issues (January-April, May-August and September-December).</p> https://ph02.tci-thaijo.org/index.php/RJST/article/view/257807 Assessment of The Working Posture Risks of Material Handling Employees: A Case Study of Food Production Company 2025-03-25T10:09:17+07:00 Maninthara Chaikhampan p.surin1980@rmutl.ac.th Sutipong Sopanut p.surin1980@rmutl.ac.th Supakit Saisom p.surin1980@rmutl.ac.th Wuttichai Songsang p.surin1980@rmutl.ac.th Sarayut Malaipun p.surin1980@rmutl.ac.th Pongsakorn Surin p.surin1980@rmutl.ac.th <p>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.</p> 2026-08-31T00:00:00+07:00 Copyright (c) 2026 Rajamangala University of Technology Rattanakosin https://ph02.tci-thaijo.org/index.php/RJST/article/view/259562 Influence of Recycled Asphalt Concrete Pavement Gradation on CBR of Mixed Materials 2025-07-15T14:48:37+07:00 Piyachat Chattonjai piyachatc@eng.buu.ac.th Weeraporn Phongtinnaboot weeraporn@buu.ac.th Sruangsuda Khunayai 63050610@go.buu.ac.th Saranchana Pattanajan 63050611@go.buu.ac.th Songpol Suwannaparteep 63050381@go.buu.ac.th Junladaphon Kunlabut 63050063@go.buu.ac.th <p>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 <br />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.</p> 2026-08-31T00:00:00+07:00 Copyright (c) 2026 Rajamangala University of Technology Rattanakosin https://ph02.tci-thaijo.org/index.php/RJST/article/view/258745 Home Visit Information System for Student Behavior Management 2025-07-26T14:50:56+07:00 Krit Chaiwannakoop krit@uru.ac.th Aekkarat Jaichana u65042380102@live.uru.ac.th Somkid Thunjai somkid@uru.ac.th <p>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 <br />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.</p> 2026-08-31T00:00:00+07:00 Copyright (c) 2026 Rajamangala University of Technology Rattanakosin https://ph02.tci-thaijo.org/index.php/RJST/article/view/257825 An experiment to measure local gravity using a cylindrical rod pendulum by the classical method 2025-04-28T09:17:03+07:00 Bancha Kongtragool bancha@northcm.ac.th Saichon Sithipong saichon@northcm.ac.th <p>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%</p> 2026-08-31T00:00:00+07:00 Copyright (c) 2026 Rajamangala University of Technology Rattanakosin https://ph02.tci-thaijo.org/index.php/RJST/article/view/261945 Growth Response of Bacopa monnieri (L.) Wettst. to Different Dilution Ratios of Organic Composting Leachate 2025-11-12T10:47:06+07:00 Apichaya Phadpin apichaya_ph@kpru.ac.th Jarukit Sangsong jarugiant1997@gmail.com Thanakorn Wongsa thanakorn_wo@kpru.ac.th <p>The study investigated the optimum proportion of leachate solution for the soilless cultivation of <em>Bacopa monnieri</em> (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. <em>Bacopa monnieri</em> (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 (<em>P</em>&lt;0.05), measuring 22.40 cm and 1.00 cm, respectively. Furthermore, the 21-day leachate solution treatment yielded the highest (<em>P</em>&lt;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</p> 2026-08-31T00:00:00+07:00 Copyright (c) 2026 Rajamangala University of Technology Rattanakosin https://ph02.tci-thaijo.org/index.php/RJST/article/view/258857 Facial recognition system for borrowing equipment 2025-07-15T13:31:17+07:00 Mallika Chatchawankitkun mallika.chkk@gmail.com Aphilap Suksamran mallika.chkk@gmail.com Warawut Settha mallika.chkk@gmail.com Sommart Thongkharn mallika.chkk@gmail.com Jaruwat Jarusombat mallika.chkk@gmail.com Chalalai Pakulanon mallika.chkk@gmail.com Kawin Jewsuwun mallika.chkk@gmail.com <p>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.</p> 2026-08-31T00:00:00+07:00 Copyright (c) 2026 Rajamangala University of Technology Rattanakosin https://ph02.tci-thaijo.org/index.php/RJST/article/view/259415 On the Solutions of Two Egyptian Fractional Equations 2025-08-18T14:55:31+07:00 Suton Tadee suton.t@lawasri.tru.ac.th <p>In this research, we have studied all positive integer solutions of two Egyptian fractional equations <img src="https://latex.codecogs.com/svg.image?\frac{1}{a}&amp;plus;\frac{1}{b}=\frac{mn}{m&amp;plus;1}" alt="equation">&nbsp;and <img src="https://latex.codecogs.com/svg.image?\frac{1}{a}&amp;plus;\frac{1}{b}=\frac{m}{p^{n}}" alt="equation">. The results showed that the Egyptian fractional equation&nbsp; <img src="https://latex.codecogs.com/svg.image?\frac{1}{a}&amp;plus;\frac{1}{b}=\frac{mn}{m&amp;plus;1}" alt="equation"> &nbsp;has twelve positive integer solutions<img src="https://latex.codecogs.com/svg.image?\left(a,b,m,n\right)" alt="equation">, which are&nbsp; <img src="https://latex.codecogs.com/svg.image?\left(2,3,5,1\right),\left(2,4,3,1\right),\left(1,2,3,2\right),\left(2,6,2,1\right),\left(1,3,2,2\right),\left(3,6,1,1\right),\left(1,2,1,3\right),\left(3,3,2,1\right),\left(1,1,2,3\right),\left(4,4,1,1\right),\left(2,2,1,2\right)" alt="equation">&nbsp;and <img src="https://latex.codecogs.com/svg.image?\left(1,1,1,4\right)" alt="equation">. The Egyptian fractional equation <img src="https://latex.codecogs.com/svg.image?\frac{1}{a}&amp;plus;\frac{1}{b}=\frac{m}{p^{n}}" alt="equation"> , where <img src="https://latex.codecogs.com/svg.image?p" alt="equation">&nbsp;is a prime number and <img src="https://latex.codecogs.com/svg.image?n" alt="equation">&nbsp;is a positive integer, has all positive integer solutions <img src="https://latex.codecogs.com/svg.image?\left(a,b,m\right)" alt="equation">, which are in the form <img src="https://latex.codecogs.com/svg.image?\left(p^{i}k,k,\frac{p^{n-i}\left(p^{i}&amp;plus;1\right)}{k}\right)" alt="equation">, where <img src="https://latex.codecogs.com/svg.image?i" alt="equation"> is an integer with&nbsp;<img src="https://latex.codecogs.com/svg.image?0\leq&amp;space;i\leq&amp;space;n" alt="equation"> &nbsp;and <img src="https://latex.codecogs.com/svg.image?k" alt="equation">&nbsp;is a positive integer with <img src="https://latex.codecogs.com/svg.image?k\mid&amp;space;p^{n-i}\left(p^{i}&amp;plus;1\right)" alt="equation">.</p> 2026-08-31T00:00:00+07:00 Copyright (c) 2026 Rajamangala University of Technology Rattanakosin https://ph02.tci-thaijo.org/index.php/RJST/article/view/259817 Comparative Evaluation of Antioxidant Potential and Basic Chemical Properties of Thai Honeys from Four Floral Sources 2025-10-30T14:14:30+07:00 Warawaran Shimbhanao warawaran@rmutl.ac.th Sureewan Rajchasom sureewan@rmutl.ac.th Janyawat Tancharoenrat Vuttijamnong vjanyawat@hotmail.com Maneerat Mueangjai mmaneerat@rmutl.ac.th Phowpinyo Shimbhanao aorphow@rmutl.ac.th <p>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.</p> 2026-08-31T00:00:00+07:00 Copyright (c) 2026 Rajamangala University of Technology Rattanakosin