Science Journal, Chandrakasem Rajabhat University

Applying Sports Science to Bodybuilding and Fitness Sports

thanatpong Sukwong, Siraprapa Pantong — Wed, 25 Jun 2025 00:00:00 +0700

This academic article aims to analyze the application of sports science in bodybuilding and fitness sports. The areas of sports science that can be beneficial for training and developing muscle shape in these disciplines include anatomy, physiology, biomechanics, psychology, nutrition, and sports medicine. Training can be divided into four periods: the form and fitness assessment period, the training and improvement period, the competition period, and the training evaluation period. Additionally, the general principles of training involve applying sports science knowledge, particularly in physiology, to determine the structure and specifics of exercise. These principles include the principle of overtraining, the principle of specificity, the principle of individualization, and the principle of reversibility. This study provides a framework for applying sports science to enhance athlete performance while minimizing injury risks in bodybuilding and fitness sports.

Editor's note

Assoc. Prof. Dr.Amnat Sawatnatee — Wed, 25 Jun 2025 00:00:00 +0700

Science Journal, Faculty of Science, Chandrakasem Rajabhat University
Volume 35, Issue 1 (January – June 2025) This issue marks Volume 35, Issue 1 (January – June 2025) of the Science Journal, Faculty of Science, Chandrakasem Rajabhat University. It features a total of eight research articles, each of which has been peer-reviewed by three qualified experts.

The Science Journal, Faculty of Science, Chandrakasem Rajabhat University is published online via the ThaiJO 2.0 system. It holds an ISSN (Online) number 2697-4584 and ISSN (Print) number 1685-0491. The journal is issued biannually: Issue 1 (January – June) and Issue 2 (July – December). It serves as a platform for disseminating academic and scientific work from lecturers, researchers, scholars, students, and interested individuals from various higher education institutions and organizations. The journal accepts both research and academic articles.

The editorial board is committed to continuously enhancing the quality of the journal in preparation for inclusion in the Thai Journal Citation Index (TCI) database.

The editorial team would like to express our sincere gratitude to all authors for their trust in submitting eight articles (one internal and seven external) for publication in this issue. We also deeply appreciate the contribution of all expert reviewers for dedicating their valuable time to evaluating the articles and providing insightful recommendations. Lastly, our heartfelt thanks go to everyone involved in the production process for their efforts in ensuring the completeness and quality of this publication.

Effects of Friction Loss Due to Elongation of Prestressing Strands in Prestressed Concrete Slabs with Different Stand Arrangements: A Case Study of a Large Building Construction Project

Wed, 25 Jun 2025 00:00:00 +0700

Friction losses due to prestressing strand elongation are a significant concern in prestressed concrete flooring systems, especially in large-scale or high-rise buildings that utilize post-tensioned concrete systems. The losses of friction may result from different arrangements of prestressing strands, therefore affecting the long-term performance and safety of building structures. This research study aims to examine the impact of friction losses caused by elongations of prestressing strands arranged in different arrangements. Compare the different values between calculated theoretical values with actual reading values at the project site, and compare these different values with the values noted in the ACI 318–19 requirements for building work by selecting a large building construction project that utilizes post-tensioned concrete flooring systems, with 17different alignments of prestressing strands. Each alignment of prestressing tendons will calculate friction losses due to the elongation of prestressing strands, following the guidelines of the ACI 423.10R-16 standard. Compare friction losses and prestressing strand elongations from values calculated theoretically and actual reading values measured on-site. The research findings demonstrate that arrangements of prestressing strands with horizontal deviations result in losses of friction due to the elongation of the prestressing strands, which are greater than in strand arrangements without deviations. The arrangements of long prestressing strands will have higher friction losses due to the elongations of the prestressing strands compared to arrangements with shorter prestressing strands. The elongation values of prestressing strands in different strand layouts indicate that differences between actual readings and theoretical values are lower than values specified in ACI 318-19 standard. Consequently, the proper configuration of prestressing strands will reduce friction losses resulting from the elongation of prestressing strands for prestressed concrete floor structures to be effective for long-term performance.

Development of Bag-type Semi-precast Concrete for Construction

Wed, 25 Jun 2025 00:00:00 +0700

This research studies the development of bagged semi-precast concrete for construction by analyzing the appropriate proportions based on the desired compressive strength. The mixture consists of grade 1 stone, cement and coarse sand without the concrete admixtures. The compressive strength and slump test were conducted on concrete samples in cubic form measuring 15x15x15 cubic centimeter, with curing periods of 7, 14, and 28 days. The results showed that the bagged concrete achieved a maximum compressive strength at 28 days of 206.9, 241, and 251 kilogram / square centimeter. The bagged semi-precast concrete for construction is convenient to user that on a budget and not need to find the proportions of ingredient.

Energy Conservation of a Split Air-Conditioner by Installing PVC Filling at Condensing Unit

Wed, 25 Jun 2025 00:00:00 +0700

This study aims to examine the installation of PVC filling media pads within an air-cooled condenser that exchanged the heat between water and hot air before the air entered the condenser. The study compared the coefficient of performance (COP), energy efficiency ratio (EER) and energy-saving cost in two cases: 1) the non-installation of PVC filling and 2) the installation of PVC filling of thicknesses 5, 7.5, and 10 cm. An air-cooled, split-type air conditioner, brand Focus, with a cooling capacity of 25,000 Btu/h. The air conditioner was set to a temperature of 25°C, with an airflow speed of 1 m/s and a cooling water flow rate of 2,500 L/h. The results showed that the PVC filling with a thickness of 10 cm provided the best energy efficiency. The EER and COP increased by 21.33% and 21.58%, respectively. Additionally, energy consumption was reduced by 5.67%, and the energy-saving cost was 817.61 baht/year. Moreover, energy conservation through the installation of PVC filling at the condenser could reduce CO₂ emissions by 96.90 kgCO₂/year.

The Effctive of an Integrated Exercise Program on the Physical fitness of patient risk of falling in Amphoe Mueang Lopburi

Puchong Thanaperm — Wed, 25 Jun 2025 00:00:00 +0700

The aim of this study was to investigate the effects of combination exercise on the physical fitness of patients at risk of falls in Muang Lopburi District. This quasi-experimental study employed a single-group pre-post comparison design with a paired t-test. The study included 45 individuals aged 60 years and older who were at risk of falling in Muang Lopburi District, Lopburi Province. Participants underwent a combination exercise program that incorporated physical health assessments, education on combination exercises, and training to enhance strength, flexibility, and balance over a 24-week period. The findings revealed significant differences (p < .05) in lower blood pressure, heart rate, body mass index, and waist-hip ratio. Additionally, a comparison of physical fitness before and after the program showed that participants demonstrated significant improvements (p < .05) in leg muscle strength, arm muscle strength, upper body flexibility, lower body flexibility, endurance, balance, and walking ability. Combination exercise is a crucial tool for enhancing physical fitness in the elderly and can help reduce the risk of falls, which are a major cause of accidents and discomfort in this population. Developing these skills can contribute to a longer and higher-quality life for older adults.

The Development of Mathematics Learning Achievement on Polynomials for Grade 8 Students Using Cooperative Learning with STAD Technique Combined with Multimedia

Thanawat Comjanwong, Prapaporn Nongharnpituk, Paweena Khansila — Wed, 25 Jun 2025 00:00:00 +0700

This research aimed to develop mathematics learning achievement on polynomials for Grade 8 students at Ban Non Theing School, Namon District, Kalasin Province, using cooperative learning with STAD technique combined with multimedia. The objectives of the study were to: 1) develop effective lesson plans meeting the 70/70 efficiency standard, 2) evaluate the effectiveness index of the learning approach, and 3) assess students' satisfaction with learning about polynomials through the developed activities. The target group comprised 14 Grade 8 students enrolled in the first semester. Research instruments included eight lesson plans, a 20-item multiple-choice achievement test, and a 20-item satisfaction questionnaire. Statistical analysis employed mean, percentage, standard deviation, E₁/E₂efficiency, and effectiveness index (E.I.). The results revealed that: 1) the lesson plans developed for polynomial learning using cooperative learning with STAD technique combined with multimedia achieved an E1/E2 efficiency of 71.61/71.07, meeting the criteria; 2) the effectiveness index of the developed learning approach was 0.6068; and 3) students expressed a high level of satisfaction with learning management ( 4.35, S.D. = 0.62).

Organization Carbon Footprint Assessment: A Case Study of SME in Fashion Industry

Chawalit Chankhantha, Phuttipong Chayanto — Wed, 25 Jun 2025 00:00:00 +0700

The objective of this research is to evaluate the carbon footprint of 25 SMEs in the fashion industry, which includes seventeen apparel businesses and eight jewelry businesses. These businesses participated in activities organized by the Department of Industrial Promotion during the fiscal year 2024. Greenhouse gas emissions data for the baseline year were collected between October 2023 and September 2024, following the assessment framework of the Thailand Greenhouse Gas Management Organization (Public Organization). The assessment is categorized into three scopes: Scope 1 (direct greenhouse gas emissions), Scope 2 (indirect emissions from energy use), and Scope 3 (other indirect emissions). The results indicate that the total greenhouse gas emissions of the fashion industry amount to 262.92 tons of carbon dioxide equivalent (tCO2-eq). Energy consumption in Scope 2 contributes the highest emissions at 134.33 tCO2-eq, followed by direct emissions in Scope 1 at 99.20 tCO2-eq, and other indirect emissions in Scope 3 at 29.39 tCO2-eq, accounting for 51.09%, 37.73%, and 11.18% of the total emissions, respectively. Electricity usage is the most significant source of greenhouse gas emissions, followed by gasohol fuel consumption for transportation and tap water usage, contributing 51.09%, 28.19%, and 8.68%, respectively. Recommendations to mitigate greenhouse gas emissions include routine maintenance of machinery to reduce repairs and enhance production efficiency, adjusting air conditioner temperatures to optimal levels, transitioning to LED lighting, adopting energy-saving technologies, and using clean energy for transportation. Organizations should also implement policies encouraging employees to conserve energy and water while optimizing resource use. These measures can significantly reduce greenhouse gas emissions and effectively address global warming.

Comparison of 50-Meter Breaststroke Speed Between Land-Based and Aquatic Leg Plyometric Training Program in Female Swimmers

Rattana Boonlue, Kajornsak Roonprapunta — Wed, 25 Jun 2025 00:00:00 +0700

This research is Quasi-experimental research design. Aimed of this study was to comparison the 50-meter spatial spatial swimming speed between the onshore leg plyometric and the inner leg plyometric. The water of female swimming athletes. The sample group in this research 20 female swimmers studied at a Suphanburi sports school province aged 15 - 18 in the year study 2020 by selecting a specific athlete population. All female swimmers come to the speed test by swimming 50 meters breaststroke of water at full speed. By using test time, there were 10 upper limb plyometric test groups and 10 aqua plyometric trials using a random sampling. Practice with upper leg plyometric program and water leg plyometric program for a total of 8 weeks,3 days a week (Monday Wednesday and Friday). Breaststroke at a distance of 50 meters was measured before and after the experiment at week 8, the results were analyzed statistically. To find mean and standard deviation and compare the difference before and after the experiment and between the experimental groups. By using t-testing the value is statistically before and after the experiment and between the experimental groups. By testing the values at statistically significant at .05. The results of the research showed 1) After 8 weeks of experiment, the female swimmer's 50-meter breaststroke swimming speed with plyometric leg training on land. The speed was statistically significantly higher than before the weaving. 05 2) After 8 weeks of experiment, the female swimmer's 50-meter breaststroke swimming speed with plyometric in the water. The speed was statistically significantly higher than before the weaving. 05
3) After 8 weeks of experiment, the 50meter breaststroke swimming speed during the plyometric training leg on land and plyometric training in the water. There was not statistically as a result has significant difference at .05