RMUTSB ACADEMIC JOURNAL

Diversity of crustose lichens on nature trail in Namtok Phlio National Park, Chanthaburi province

Chawanrat Somnuek — 2024-06-11

Lichens are symbiosis organisms between fungi and algae. Lichens are widely used in ecological and environmental applications, for example, to assess ecosystem changes and as an indicator of air quality in each area. This study aimed to survey the species of crustose lichens along the nature trail in Namtok Phlio National Park. The 45 samples were collected from the bark of trees, at ten learning stations distributed throughout the 1.2-km long nature trails. In the laboratory, the specimens were taxonomically classified based on morphological, anatomical, and chemical constituent substances using spot test and thin layer chromatography (TLC). The samples could be identified into seven families. The third most prominent family of lichen was Graphidaceae, with 25 samples (9 genera, 12 species, 4 unidentified species), followed by Pyrenulaceae with 8 samples (1 genus, 4 species, 1 unidentified species) and Trypetheliaceae with 5 samples (2 genera, 1 species, 1 unidentified species), representing 56, 18 and 11 percent, respectively. All the lichen families in this study were classified as resistant to pollutants. In addition, the Trypetheliaceae family was reported to be sensitive to human disturbance. It shows that the National Park still maintains the area very well even though there are many tourists visiting the area.

Optimal high-pressure processing for ready-to-eat banana jelly enriched with dietary fiber

Jaruwan Thongsanit Okumura — 2024-06-11

In Thailand, the accumulation of degraded-overripe bananas resulting from the drying process remains a substantial challenge for banana processors. Utilizing these by-products to create jelly with enhanced nutritional content and dietary fiber, via a non-thermal sterilization technique, presents a promising solution for value added. Consequently, this study was designed to refine the process of producing banana jelly enriched with dietary supplements through High-Pressure Processing (HPP) and to examine the quality alterations during a three-month storage at 4°C. The findings indicated that the most effective HPP condition for cold sterilization was at 600 MPa and 45°C using water as the pressure medium for 10 minutes. This condition successfully reduced the microbial load of Escherichia coli K12 ATCC 47076 and Listeria innocua DMST 9011 by more than 5 log CFUs, specifically to 5.78 and 6.72 log CFU/g, respectively. Additionally, at 35°C for 15 minutes condition also effectively decreased E. coli K12 and L. innocua counts by 5.66 and 6.34 log CFU/g, respectively. Over the three months of storage at 4°C, the jelly's color (Delta E: ∆E) experienced only minor variations between 0 and 0.64 (consumers cannot distinguish color changes), with no detectable microbial growth, including total viable counts, yeast, and mold.

Appropriate harvest date of Nam Wah banana on the production of reduced sugar solar dried banana using ultrasonic technology

Jakapan Rodsup — 2024-06-11

The ripening stage of bananas resulted in high sugar content in solar-dried bananas. Utilizing early-harvested bananas as raw materials and applying ultrasonic technology for porous in plant tissue may be an approach in the development of reduced-sugar solar-dried banana products. This research aims to produce reduced-sugar solar-dried bananas by comparing three banana harvest ages and applying ultrasonic treatment to fresh bananas before drying at frequencies of 40, 80, 135, and 200 KHz for 30 or 60 seconds. It was determined that bananas harvested at 110 days after flowering (DAF) were found to be suit for solar-dried banana production, exhibiting a Brix/acid ratio of 787.87, total soluble solids (TSS) of 26.0ºBrix, malic acid of 0.033%, reducing sugar of 136.05 mg/g, and non-reducing sugar of 27.30 mg/g, respectively. Samples subjected to 30 seconds of four ultrasonic treatments showed reductions in the concentration of TSS, reducing sugar, and non-reducing sugar ranging from 13.89% to 15.28%, 10.30% to 25.29%, and 27.47% to 46.96%, respectively. Furthermore, samples performed with 60 seconds of ultrasonic treatment showed significantly greater decreases in reducing sugar (19.69% to 30.32%) and non-reducing sugar (42.97% to 56.59%) compared to samples dried using the conventional method. It was also found that subjecting fresh bananas to ultrasonic treatment before drying could reduce the hardness of solar-dried bananas. These findings indicate the potential application of ultrasonic technology in the production of reduced-sugar solar-dried bananas.

Growth potential, herbage yield, and nutritional value of 10 sugarcane hybrids (Saccharum officinarum x S. spontaneum) for sugarcane forage usage

Pranee Buathong — 2024-06-11

Sugarcane hybrids (Saccharum officinarum x S. spontaneum) are tolerant to drought, exhibit good tillering, have a high dry matter content, and are suitable for use as ruminants feed. The present study aimed to evaluate the growth, yield, and nutritional value of sugarcane hybrids. The field experiment was conducted at Kamphaeng Phet province in 2021-2022. The field experiment was arranged in RCBD with 4 replications, and consisted of 10 clones of sugarcane hybrid (clone 1-124, 1-131, 1-144, 2-180, 2-200, 2-42, 3-20, 3-22, KU58-5-6 and KU58-5-7) with two check sugarcane varieties (Khon Kaen 3 and Biotec 2) and Napier grass. The growth measurements, yield, and nutritional values including contents of crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) were collected. The results showed that the clones KU58-5-6, KU58-5-7,3-22, 2-42, and 2-200 had an average plant height of 97, 93, 88, 97 and 92%, respectively, compared to that of Biotec 2, which exhibited the highest average plant height. Clone 3-20 produced the highest average tiller number (15.10 tiller/clump). Clone 2-200 had a higher average fresh biomass yield (4,820 kg/rai) than Napier grass and Biotec 2. All sugarcane clones showed an average total fresh biomass yield range of 81-119% compared to Napier grass. For nutritional value, the leaves of sugarcane clones had a higher average CP content than the stem, and the average CP content in the leaves of the six sugarcane clones was lower than that in Napier grass. The average NDF and ADF contents of stems in clones 1-131, 1-144, 2-180, 2-200, 3-22, KU58-5-6, and KU58-5-7 were lower than those in Napier grass. The average ADL content of sugarcane clone 1-131 and 2-200 had lower than Napier grass. Based on physiological and nutritional values, it is indicated that sugarcane clone 2-200 shows potential as ruminant animal feed.

Efficiency of biofloc application on growth, survival rate and water quality change in intensive hybrid catfish culture in indoor pond

Jesada Is-haak — 2024-06-11

The efficiency of biofloc application in intensive hybrid catfish culture in indoor ponds, compared to the control group without biofloc adding, was investigated. The experimental units were 6 of 3-meter-diameter PE rounded ponds, with 75 cm depth and 5.30 m³ of water volume. The experimental fish, with initial average weight and length of 1.24+0.09 g and 5.03+0.07 cm, respectively, were stocked at the stocking density of 1500 fish per pond. The experimental feed was commercial floating pellet. The trial was conducted for 17 weeks. The data of growth performance and survival rate of fish were recorded, including the water quality in experimental ponds. At the end of the experiment, it was found that average weight, average weight gain, daily weight gain and survival rate of fish in biofloc treatment, which were 188.90+4.67 and 168.40+3.82 g, 187.65+4.60 and 167.17+3.71 g, 1.58+0.06 and 1.41+0.04 g/day and 95.00+1.73 and 85.00+0.00%, respectively, were significantly higher than those of the control group (P<0.05). On the other hand, the FCR and feeding cost of 1 kg of fish, which were 1.33+0.04 and 1.50+0.19, and 33.08+0.12 and 36.38+1.05 Baht per kg, respectively, were significantly lower than those of the control group (P<0.05). The feed cost could be reduced by 3.30 baht per 1 kg of fish. Water qualities, throughout the experimental period, were in the optimal range for hybrid catfish growth. Biofloc application data had high negative Pearson's correlation coefficients to the ammonia (r=-0.89^**) and also moderate positive correlation coefficients to phosphorus (r=0.57^*).

Productivity improvement of material handling using Karakuri Kaizen hand truck: A case study of Phuwiangwari community enterprise

Chaiwat Kittidecha — 2024-06-11

The objective of the project is to develop the material handling and optimize the equipment for material handling of Phuwiangwari community enterprise, Lamphun province. It was found that this enterprise used a 2-wheeled steel trolley for handling the product, then the worker was exhausted and impacted for other jobs. The Karakuri Kaizen idea was applied for design and fabricate apparatus for crate transportation. The Karakuri mechanism is autonomous equipment without the need of an electric motor, leading to decrease the costs. The dimension of Karakuri Kaizen cart was 800 mm in width, 600 mm in length, and 1,700 mm in height, using the gravity force. When the weight of the cargo crate reached the specified value, the product tray would move down one level. The drop-down distance was applied from the height of the crate. Therefore, loading the next crate would be at the same level as loading the first crate. The workers did not have to bend down. Test results showed that fatigue in moving crates was significantly reduced, and also reduced the time for moving per load or 6 crates of goods from the standard time for moving with a 2-wheeled steel trolley of 1.10 minutes to 1.01 minutes, referred as 9% reduction. The fatigue assessment results found that the pain at the maximum level decreased from the level of feeling a lot of pain or fatigue to the level of feeling moderate pain. The lower back was the part of the body that still experienced the most fatigue, and overall fatigue was greatly reduced, meaning there were 5 parts of the body that didn't feel tired, instead of only 1 part.

Error assessment of distance measurement by small, low-cost unmanned aerial vehicles without real time kinematic point

Yodchay Singthong — 2024-06-11

The application of unmanned aerial vehicles (UAVs) in various fields has gained global recognition, particularly in civil engineering projects where they play a significant role. In tasks such as rapid surveying and resource-efficient operations, small-sized, cost-effective UAVs have become instrumental. This research aims to propose a methodology for assessing distance measurement accuracy using small-sized, low-cost UAVs, eliminating the need for costly Real Time Kinematic (RTK) satellite signal receivers, diverging from previous studies that often-required extensive resources and complex procedures. The research methodology involved three key steps: 1) Building a geometric shape distance measurement model consisting of three shapes: triangle, square, and pentagon 2) Defining the lengths of each side randomly, ranging from 34-38 meters and 3) Measuring the lengths using a tape measure and comparing the results with measurements obtained through image processing from aerial photographs at an altitude of 90 meters. The testing was conducted in an obstacle-free, flat terrain. The comparative analysis revealed that the average measurement errors for triangle, square, and pentagon shapes were 0.12, 0.15, and 0.14 meters, respectively, or 0.98%, 0.43%, and 0.37% in percentage terms. These discrepancies may be attributed to unclear reference points in certain positions within the images. However, when compared to human-based measurements, the UAV measurements demonstrated minimal motion, making them suitable for preliminary surveying work.

A solution to the shortest path problem in communication networks based on Q-learning

Danuphon Yingyong — 2024-06-11

This paper proposes an application of a Q-learning algorithm to solve the shortest path problem in communication networks, which are widely used in both wireline and wireless communications. The objective is to minimize the cost occurred in a transmission process. The cost may refer to transmit power and time delay. To bench mark such a proposed method, Dijkstra’s, Bellman-Ford’s, and Floy-Warshall’s algorithms, which are existing methods, are taken into a comparison. The research method begins with studying Dijkstra’s, Bellman-Ford’s, and Floy-Warshall’s algorithms to obtain some insights of advantages and disadvantages. In applying the Q-learning, the shortest path problem is decomposed into Q-learning’s components such as agent, action, state, environment, and reward which can be completely used in training process. Experimental results show that all methods provide the same solution. For the Q-learning method, it can be stated that this method requires a small number of episodes in training procedure e.g., 35 episodes for the interested example. Furthermore, it can also be found that the Q-learning algorithm offers all paths for any sources to the destination node. This is comparable with the Floy-Warshall’s algorithm. However, the Q-learning method requires less complexity in calculation. Furthermore, it can be concluded from the study results that the Q-learning method can be applied in multiple source-destination pairs.

Input power control of grid-connected inverters under a low irradiance condition to improve efficiency and power quality for distributed rooftop photovoltaic systems

Kittiphong Khaidee — 2024-06-11

From increasing the trend of the rooftop photovoltaic (PV) system and reducing the performance of grid-connected inverters with low irradiation, this paper presents the efficiency and power quality improvements of the grid-connected PV system by controlling the input power of inverters under low irradiance conditions. The relationship between efficiency and power was utilized by using PVsyst simulation to control the proper inverter parallel following the power of solar cell panels on the changing irradiance. Moreover, in this paper, the different output power of inverters on the total harmonic distortion of currents (THDi) was also considered. The research results revealed that the output power of inverters with the proposed method under low irradiance conditions could be increased from 63.29 W to 76.58 W. Consequently, the efficiency of the proposed method was more than that of the conventional distributed PV system. As a result, it could be able to boost the energies by 21%. Furthermore, the experimental results also clearly confirmed that increasing the input power under low irradiance conditions affects the decrease of the THDi from 18% to 11.25%.

Appropriate battery energy storage system for house-based in case of charging system for EV installation

Nopphamat Promasa — 2024-06-11

This paper presents the analysis of the battery energy storage system (BESS) appropriating for a house-based on installation of a charging system for electric vehicle (EV). The charging system taps into both the Metropolitan Electricity Authority's (MEA) low-voltage power grid, and a rooftop solar photovoltaic system. By using data on the daily electrical energy demand (load profile), the total electrical energy consumption was 20.39 kWh/day, which was used to simulate and analyze an appropriate battery energy storage system by using the DIgSILENT PowerFactory program. In the case of installing a charging system for electric vehicles (electric vehicles: EV), the portable charge rate of an electric vehicle was 3.60 kW (current 16.00 A), which an average daily energy consumption of 37.20 kWh with an average daily residential electricity consumption of 20.39 kWh. All loads were connected to a 5.00 kWp rooftop solar power generation system and the MEA's low-voltage grid. Results of simulation and analysis found that the load use of rooftop solar generation system during daytime was 6.04 kWh, and battery energy storage system suitable for storing remaining energy from solar rooftop production was 18.52 kWh, which can reduce the average daily electrical energy consumption from 57.60 kWh down to 33.04 kWh.

Editorial statement

Natthapong Wongdamnern — 2024-06-11

วารสารวิชาการ มทร. สุวรรณภูมิ ปีที่ 12 ฉบับที่ 1 (มกราคม - มิถุนายน 2567) ประกอบด้วย บทความวิจัย (Research article) จำนวนทั้งสิ้น 10 บทความ โดยเป็นบทความด้านวิทยาศาสตร์ เทคโนโลยีการเกษตร และวิศวกรรมศาสตร์ ซึ่งตรงกับเป้าหมายและขอบเขตของวารสาร (Aim and scope) ในวารสารฉบับนี้ บทความส่วนใหญ่จะเป็นบทความด้านวิศวกรรมศาสตร์และเทคโนโลยีการเกษตร ในด้านวิศวกรรมศาสตร์ มีบทความที่น่าสนใจและเต็มไปด้วยองค์ความรู้และเทคโนโลยีใหม่ ๆ ในสาขาวิชาต่าง ๆ อาทิ วิศวกรรมไฟฟ้า วิศวกรรมโยธา วิศวกรรมอิเล็กทรอนิกส์ และวิศวกรรมอุตสาหการ ในขณะที่ในด้านเทคโนโลยีการเกษตร มีบทความที่เกี่ยวข้องกับการพัฒนาผลิตภัณฑ์ทางการเกษตรทั้งพืชไร่และประมงน้ำจืด ซึ่งบทความทั้งหมดเหล่านี้จะก่อให้เกิดประโยชน์ในด้านการให้องค์ความรู้ แนวทางการใช้ประโยชน์ และแนวทางในการพัฒนาแก่หน่วยงานที่เกี่ยวข้อง ตลอดจนวิศวกร เกษตรกร ผู้ปฏิบัติงาน และผู้สนใจต่อไป

ทุกบทความในวารสารฉบับนี้ ได้รับการประเมินคุณภาพทางวิชาการจากผู้ทรงคุณวุฒิในสาขาวิชานั้น ๆ แต่ละบทความมีความใหม่ มีความน่าสนใจและมีองค์ความรู้และเทคโนโลยีที่ทันสมัย ซึ่งจะเป็นประโยชน์สำหรับนักวิจัยและผู้สนใจทั่วไป ที่จะนำองค์ความรู้ที่ได้ไปต่อยอดงานวิจัยในระดับที่สูงขึ้น ตลอดจนนำเทคโนโลยีที่เหมาะสมไปประยุกต์ใช้ให้เกิดประโยชน์ในทางปฏิบัติ กองบรรณาธิการขอขอบคุณผู้ส่งบทความทุกท่านที่เลือกวารสารวิชาการ มทร. สุวรรณภูมิ เป็นที่เผยแพร่ผลงานวิจัยและหวังเป็นอย่างยิ่งว่าวารสารฉบับนี้จะเป็นประโยชน์ต่อนักวิชาการ นักวิจัย และผู้สนใจทั่วไป