Recent Science and Technology

Design of a Lidar-Based Safe Braking Distance Warning System for Small Electric Vehicles

Soontorn Odngam — 2024-12-17

This paper presents a braking distance warning system design using LiDAR technology to measure distances when approaching an object. The objective was to study and develop a system for vehicles that provides warnings before a potential collision occurs. The proposed system was designed for installation in small vehicles that lack basic driving assistance systems to detect objects in front of the vehicle. The current research divides the braking distance for testing into four zones: Zone 1 - Safe distance (greater than 700 cm from an object), Zone 2 - Caution distance (250 - 700 cm), Zone 3 - Brake distance (25 - 250 cm) and Zone 4 - Stop distance (less than 25 cm). In order to conduct this study, a prototype vehicle was moving toward an object at a constant speed of 15 km/hr. It was found that when the prototype was positioned 767.67 cm in front of the object, the warning system would display a green light to indicate a safe distance. When the prototype approached the object at a distance of 593 cm, it would indicate a yellow light for a caution distance. Once the vehicle reached the object at a distance of 237.67 cm, a red status indicator for braking distance was shown. Finally, when approaching the object at a distance of 23 cm, the system would initiate a speed reduction with a deceleration of 0.524 m/s2. This investigation showed that the proposed system was able to operate according to the specified conditions with a braking error of 5.77% from the designated distances. The system developed in this work can be applied to larger-sized vehicles to assist in braking or automatically reduce speed, thereby minimizing the occurrence of accidents.

Phytochemical Screening and Study of Cholesterol Esterase Inhibitory Activity of Extracts from Stem of Dipterocarpus intricatus Dyer

Orapun Jaisamut — 2024-12-17

Dipterocarpus intricatus Dyer is a medicinal plant used for relieving muscle soreness (bark) and curing wounds (resin). This study investigates chemical composition and cholesterol esterase inhibitory activity of D.intricatus stem harvested from Phrasaeng District, Surat Thani Province, Thailand. Using chromatographic method and spectroscopic analysis, two known compounds, dipterocarpolic acid (1) and bergenin (2), were isolated and identified as a triterpene and a coumarin, respectively. Cholesterol esterase inhibition activity of dipterocarpolic acid (1) and bergenin (2) at concentration of 1.0 mg/mL was 35.22±1.44%, and 42.01±1.65%, respectively, whereas methanolic extract showed activity of 31.70±1.23% at 5.0 mg/mL, compared to orlistat (99.55±0.53%). Therefore, D. intricatus extracts are another alternative for further studies in herbal medicine and natural product development.

A New Yeast Strain, Nakaseomyces glabratus DL5, Isolated from a Mangrove Forest in Chonburi Province and Its Potential for Lipid Production

Nisarat Sitthisom — 2024-12-17

This research aimed to search for oleaginous yeasts from mangrove forest resources and primarily investigated their potentials for lipid production. Ten of soil and decaying leaf samples from the Nature Education Center for Mangrove Conservation in Chonburi province were collected and used for the isolation of yeasts on Yeast extract peptone dextrose medium. A total of 38 yeast strains were isolated in which 11 yeast isolates (DL1-DL11) and 27 yeast isolates (S1-S27) were obtained from decaying leaf and soil samples, respectively. These yeast isolates were screened for their high lipid accumulation by Nile red fluorescence assay. Of 38 yeast isolates, five isolates, DL5, S7, S8, S10 and S2, showed the possibility of being oleaginous strains. Those five isolates of yeast were selected based on their potentials of lipid accumulation and further visualized for their ability to accumulate intracellular lipid by Sudan Black B staining. Results showed that isolate DL5 obtained from the decaying leaf sample had the most distinct intracellular lipid accumulation in comparison with the other isolates. Identification of isolate DL5 was found to be Nakaseomyces glabratus on the basis of ITS1- 5.8S rDNA - ITS2 sequence. Further investigation of lipid production by N. glabratus DL5 showed that this strain achieved a lipid content of 9.61 ± 2.17 % of dry biomass weight at 120 hours of growth in DMY broth. These results are important preliminary data for further optimization to improve lipid production and accumulation in the yeast for future applications.

Rice (Oryza sativaL.) Seed Quality after Storage in the Humid Tropicsand after Accelerated Aging

Pongsit Chor-unchun — 2024-12-17

Accelerated aging test (AA) has been applied as a technique to evaluate seed vigor and to predict seed storability. This study evaluated the storability and vigor of Sang Yod Phatthalung, Leb Nok Pattani,and Chaing Phatthalung rice seeds by the AA. The seeds were subjected to AA at 42, 44, 46, and 48°C for durations of 48, 72, 96, and 120 h at 100% relative humidity. The seeds were stored in woven plastic bags at room temperature (28±1°C) for 12 months, and were sampled for physical and physiological quality tests every two months. The results showed that Sang Yod Phatthalung, Leb Nok Pattani, and Chaing Phatthalung rice seeds had 94.75-97.25% germination and 9.05-9.98% seed moisture content, and could be stored in the humid tropics for six months with above 80% germination. It suggests that the appropriate AA conditions for the evaluation of rice seed storability in the humid tropics should be done at 46°C for 96 h and 100% relative humidity. This aging regime gave seed vigor separation among varieties with a germination gap of about 10%, while a greater classification (10-30%) occurred after aging at 44°C for 120 h. These AA regimes (46°C for 96 h) serve as a potential tool for predicting the seed storability and classifying rice seeds by their vigor.

Study on Physical and Chemical Quality of Fourfinger Threadfin (Eleutheronema tetradactylum) from Bang Tawa Sub-district,

Phattharawadee Aedtem — 2024-12-17

Bang tawa Sub-district, located in Nong Jik District, Pattani Province, is known as an important fishing ground for "Pla Kulao" (Fourfinger threadfin). The fish caught in this area are primarily processed for salting. However, there is a lack of statistical data on the quantity of Fourfinger threadfins in this area and their post-harvest quality. Hence, this research aims to study the quantity and quality of catches, as well as their storage, during the fishing season. The study revealed that the catch quantity of Fourfinger threadfin in the Bang tawa Sub-district amounted to 8,366.6 kilograms/year. The highest catch quantity was recorded in January, with 2,013.6 kilograms/year. The physical and chemical quality of Fourfinger threadfin with three sizes was studied, and the fish were classified into three weight ranges. Samples were collected every 3 months, namely in January, April, July, and October. The average protein content for each weight range was as follows: 19.97%, 22.79%, 24.35%, and 22.99%, respectively. The 1-2 kilograms Fourfinger threadfin showed the highest protein content in every month (p<0.05). For each weight range, the average fat content was 2.52%, 2.20%, 2.82%, and 2.84%, respectively. Additionally, the fat content in female Fourfinger threadfin was 1.32 times higher than that in males. The TVB-N value, which indicates fish deterioration, had the highest value of 21.51 (mg/100 g)in April. When analyzing the correlation between chemical properties and freshness score of Fourfinger threadfin, it was found that physical characteristics were positively correlated with chemical properties (p<0.01). Regarding the preservation of fresh Fourfinger threadfin for salted fish production, chilling (10±2 °C) allowed preservation for 3 days, whereas freezing (-18±2 °C) extended preservation beyond 30 days.

Determination of Benzoic Acid and Sorbic Acid in Salad Cream and Mayonnaise Samples Using Optimized Microextraction Followed by High Performance Liquid Chromatography

Pimpimol Phukpattaranont — 2024-12-25

This research has developed an analytical method for simultaneously determining two preservatives, namely benzoic acid and sorbic acid, in salad cream and mayonnaise by high performance liquid chromatography (HPLC). The chromatographic separation was performed on a Hypersil GOLD (5 micrometers, ID 4.6 mm, length 150 mm) column with gradient elution of 0.02 M aqueous KH2PO4 (pH 5) and acetonitrile with a 1.0 mL/min flow rate and UV detection at 220 nm. For both benzoic acid and sorbic acid, the limit of quantification (LOQ) was 0.02 mg/L, whereas the limits of detection (LOD) were 0.007 and 0.006 mg/L, respectively. Excellent linearity (R2 > 0.9997) was obtained over the concentration range of 0.02-100 mg/L. The high accuracy of two compounds was presented by % recovery. While the % recovery of benzoic acid and sorbic acid in the salad cream sample was in the range of 89.6–99.4% and 90.6–98.3%, respectively, the % recovery of benzoic acid and sorbic acid in the mayonnaise sample was in the range of 99.4-104.3% and 101.3-103.9%, respectively. For benzoic acid and sorbic acid in salad cream samples, the repeatability (intra-day) values were 0.1%, and the intermediate precision (in 3 days) values were 0.2%. In addition, benzoic acid and sorbic acid in mayonnaise samples had repeatability (intra-day) values of 0.1% and intermediate precision (in 3 days) values of 0.2%. For the sample preparation method, the study indicates that dispersive liquid-liquid microextraction (DLLME) can reduce matrix interferences better than liquid-liquid extraction (LLE) does. The matrix effect evaluated by one-way analysis of variance (ANOVA) from DLLME was significantly different at the 95% confidence level compared with that from LLE. The advantages of DLLME also include environmental friendliness by reducing the amount of organic solvent used, simple extraction, low cost, and time efficiency.

Utilization of Avocado as a Fat Replacer in Healthy Chocolate Custard Filling

Achara Dholvitayakhun — 2024-12-25

This research aimed to develop a healthy chocolate custard filling product by replacing fat with avocado and using maltitol to replace sucrose in varying ratios. The study investigated fat replacement with avocado in products by substituting 25, 50, 75, and 100 of butter by weight. The results showed that increasing the amount of avocado resulted in lower lightness (L*) and yellowness (b*) values, while redness (a*) and moisture content were increased (p≤0.05). The sensory evaluation revealed that the overall liking score for 100% avocado replacing butter was moderate (7.09±1.41), which reduced butter use in the chocolate custard filling by 100%. Moreover, the sucrose was replaced with maltitol at levels of 25, 50, 75, and 100 by weight of the total sucrose. The results showed that increasing the amount of maltitol resulted in higher values of lightness (L*) and yellowness (b*), moisture content, and water activity. At the same time, the redness (a*) and spread ratio were decreased (p≤0.05). However, replacing 100% avocado and 100% maltitol in the chocolate custard filling product showed the highest overall ranking, with scores falling within a medium range (7.23±1.91). The nutrition values per serving (15 grams) showed that the developed product consisted of 5 grams of carbohydrates, 1 gram of fat, 1 gram of sugar, and 31 kilocalories of energy. This provided no more than 40 kilocalories of energy per serving aligning with the criteria set by the Ministry of Public Health of Thailand (issue182), making this chocolate custard filling, which replaces butter with avocado, to be classified as a low-calorie. Therefore, this product can be developed into a healthy food option in the future.

Genetic Variation of Long-Whiskered Catfish (Mystus gulio) Population Using Microsatellite DNA for Hatchery Broodstock Management

Chaowalee Jaisuk — 2024-12-25

Long-whiskered catfish (Mystus gulio) is attractive and promoted in aquaculture due to consumer demand, but there is a lack of fry. This study emphasizes on good management for offspring production to support aquaculture. Therefore, operations should possess sufficient population genetics information to effectively manage broodstock for producing the target offspring. Brood-stock samples were collected from a farm located in Chanthaburi province, Thailand. They were divided into two groups: male and female. Six microsatellite loci developed for M. nemurus were used to assess population genetic variation of M. gulio in the study. The results revealed that the markers could be used for cross-species studies with M. gulio. These microsatellites were polymorphisms. M. gulio males and females showed no significant difference in genetic diversity (p > 0.05), and the effective population size (N_e) was infinite. A bottleneck was detected in males, considering that N_e was exceeded. The results indicated that increasing broodstock numbers could enhance genetic diversity. Genetic differentiation between males and females showed significant values (p < 0.05). Consequently, maintaining genetic diversity level and phenotype of domesticated stockrequires careful brood-stocks management to prevent inbreeding, genetic drift, and negative selection. Improvement of broodstock management practices will have a positive long-term impact of M. gulio production.

Techno-economic Analysis of Heat Pump Assisted Solar Dryer for Krajood

Jaruwat Jareanjit — 2024-12-25

This study applies solar energy-assisted heat pumpdryer for Krajood. The prototype solar-assisted heat pump drying system was designed to evaluate heat transfer efficiency and to conduct economic analysis for potential implementation. In the study, temperatures of 45°C, 55°C, and 65°C were investigated. Experimental results indicated that the optimal drying temperature was 55°C, achieving a balance between energy efficiency and product quality. The solar-assisted heat pump drying system exhibited a specific energy consumption of 2.67 kWh/kg and a thermal efficiency of 22.13%. The drying time with the solar-assisted heat pump dryer (22 hours) for 10 kg of Krajood was proven to be shorter compared to open solar drying of Krajood (batch 24 h or 3 days). An economic analysis employing Net Present Value and payback period revealed significant economic benefits over a 5-year lifespan. The payback period for Krajood drying (2.9 years) aligned well with previous studies. These findings demonstrate the economic feasibility and potential of solar-assisted heat pump dryer for reducing postharvest losses of Krajood, particularly in developing countries.

Cricket Frass Decomposition of Ammonia and Carbon Dioxide Emission

Sarawut Saenkham — 2024-12-25

Cricket frass in ponds is a waste that continually accumulates, potentially affecting the quantity and quality of cricket farming. This research aims to study the factors of temperature (28, 35, and 40 °C), moisture content (20, 25, and 30%w.b.), and cricket frass (4.17, 8.68, and 12.86 kg/m²) affecting decomposition, NH3, and CO₂. A fractional factorial experiment planned with 15 treatments, each condition repeated three times, was conducted in a temperature-controlled sample box measuring 0.40 meters in width, 0.60 meters in length, and 0.37 meters in height. New cricket frass was prepared after harvesting and cleaning, with moisture content levels adjusted as needed. The bio decomposition test involved sampling cricket frass according to specified moisture content levels, placing 15-gram samples in aluminum containers, packing them in temperature-controlled sample boxes under 15 conditions with 18 samples per box, and removing them weekly for 6 weeks to determine dry weight (without returning the samples). NH₃ and CO₂ were tested under temperature and moisture content conditions corresponding to cricket frass quantity. Gas production was recorded daily for 42 days. Decomposition rate, NH₃, and CO₂ were analyzed statistically, along with their relationship to the test factors. The results revealed that NH₃ was primarily found at the bottom of the pond, whereas CO₂ was distributed throughout the experimental pond. Decomposition was more pronounced in the high-factor level group compared to the medium and low-level groups. Over the six-week test period, cricket frass mass decreased by approximately 10% compared to the initial mass. NH₃ and CO₂ behavior indicated that NH3 generation peaked quickly, reaching a maximum value of
90-63 ppm between days 2 and 7 before gradually decreasing until the end of the experiment. CO₂ production peaked rapidly within 1-3 days, reaching a maximum value between 1050-960 ppm, followed by a rapid decline until stabilizing at a level similar to atmospheric levels. Therefore, at low factor levels, low decomposition results in low values of both NH₃ and CO₂, making them suitable for cricket farming conditions.

Biogas Production Potential from Anaerobic Digestion of Food Waste and Pre-Treated Water Hyacinth by Hot Air Oven and Hot Water Bath

Nanthanat Sriprasert — 2024-12-26

This research aims to study the treatment and utilization of organic wastes, namely food waste (FW) and the primary surface water weed, water hyacinth (WH), for biogas production through anaerobic digestion. It includes evaluating the effect of thermal pre-treatment of WH by using temperature-controlled hot water bath (WHB) and hot air oven (WHO) techniques for mono-digestion and co-digestion of both substrates in batch experiments at mesophilic temperatures for 40 days. It was found that FW and WH were good substrates for biogas production since they consist of high organic substances in terms of VS, accounting for more than 74 %TS. WHB presented a higher tendency to increase the amount of readily organic fractions as substrate in biogas production compared to WHO when considering CODs, VFAs, and Org_N. The mono-digestion of FW had the highest BY value of 189 mL_biogas/gVS_addeddespite having a high F/M of 4.58 with Volatile Solid Destruction (VSD) of 59.19 %. The WHB digestion had 1.9 folds higher Biogas Yield (BY) than the WH digestion, while the BY of WHO digestion was only slightly different from that of WH digestion, with values of 28 and 24 mL_biogas/gVS_added, respectively, at similar F/M ratios of 1.3-1.4. The results of co-digestion with a substrate mixing ratio of FW and WH (treated and untreated)
~ 80-90 % FW: 10-20 % WH, resulting in an F/M value of ~ 3-3.6 showed that BY was WHB > WH > WHO. Meanwhile, in the ratio ~ 60 % FW: 40 % WH (F/M ~2.3), WH pre-treatment had almost no effect on BY, with WH > WHO > WHB. This is because BY was obtained mainly from the digestion of FW fraction. As a result, BYs of co-digestions were 122-179 mL_biogas/gVS_added with VSD of 61.1-74.1 %.

Development of an E-commerce Application System for Durian Entrepreneurs in Narathiwat Province, Thailand

Surachet Sangkhapan — 2024-12-26

This research and development project aims to create an application for managing processed durian products to support B2B2C e-commerce. The objectives are to 1) study relevant data, 2) design the system architecture, and 3) evaluate system efficiency. The sample group consists of the processed durian community in Bukit Subdistrict, Cho-I-Rong District, Narathiwat Province. The development follows the SDLC model, using NextJS with Server-Side Rendering (SSR) for the frontend, Node.js for the backend, and Firestore on Firebase as a NoSQL database. The system comprises seven core modules: member management, product management, order management, payment channels, database management, multi-vendor management, and reporting. Evaluation by two experts and 30 users shows that the system performs excellently, particularly in meeting user requirements ( = 4.67, S.D. = 0.49), system functionality ( = 4.62, S.D. = 0.55), ease of use ( = 4.57, S.D. = 0.49), and data security ( = 4.60, S.D. = 0.56). The research results indicate that this system is efficient and can be implemented in real-world scenarios. It helps connect community products to online markets through social media, increases sales channels, and can potentially aid in controlling product prices and quality in the future.

The Statistical Forecasting of COVID-19 Infected People in Thailand

Jutharath Voraprateep — 2024-12-26

The research objectives are to compare the statistical forecasting of COVID-19 infected people in Thailand using four techniques: global constant mean model, local constant mean model, adaptive forecasting and Box - Jenkins; and to study the errors from the statistical forecasting using MAD, MSE and MAPE to select the appropriate forecasting. This research has taken the number of COVID-19 infected people from the Center for COVID-19 Situation Administration (CCSA) between 1st April 2022 and 31st October 2022 (7 months or 214 days) for forecasting COVID-19 infected people in Thailand. The research results were summarized as follows: the minimum number of COVID-19 infected people was 26 persons in April and the maximum was 23,418 in August. The average number of COVID-19 infected people for 7 months is 8,802 persons, and the top three with the least MAD, MSE and MAPE for statistical forecasting of COVID-19 infected people in Thailand are single exponential smoothing with smoothing constants of = 0.1 and 0.5, and single moving average with n = 2.

Effect of Chicken Meat Protein on Gel Properties of Different Surimi Quality

Daungdoen Kulwilai — 2024-12-26

Surimi is often used as a raw material for fish jelly products, which sometimes face raw material shortages or have low quality. The improvement of functional properties of medium quality (SM) and low quality (SL) surimi gels with breast chicken meat was investigated. The chicken gel preparation conditions were studied by comparing unwashed minced chicken (UW) and minced chicken rinsed 3 times (W) with ground chicken meat to ice water ratio (w/w) of 1:4. The mixtures were heated at 40 °C for 30 min, followed by 90 °C for 20 min (40/90), and at 60 °C for 30 min, followed by 90 °C for 20 min (60/90). Then, the mixtures of surimi and chicken meat at ratios (w/w) of 75:25 and 50:50, heated at 40/90 and 60/90 were compared with mixtures of chicken meat at 60/90 and surimi at 40/90. The 50:50 ratio and 60/90 °C treatment gave optimum gel properties, with breaking force, breaking distance, gel strength, springiness, cohesiveness and chewiness higher than those of 40/90. Breaking force, hardness and chewiness increased from surimi gel by 1.45, 2.14 and 1.92 times, respectively. Moreover, the mixed gel had higher gel strength, hardness, chewiness than those of the 75:25 ratio (p≤0.05). In contrast, the 50:50 ratio of SL and chicken gels at 60/90 and 40/90 showed no differences in gel properties (p>0.05), while gel strength, springiness, cohesiveness, L*, b*, and whiteness were higher than those of the 75:25 ratio (p≤0.05). The breaking force, hardness, springiness, cohesiveness and chewiness of the 50:50 ratio increased from the surimi gel by 1.34, 1.71, 1.14, 1.71 and 3.31 times, respectively. Therefore, adding water-washed chicken to the surimi could greatly improve the texture of medium-quality surimi and slightly improve the texture of low-quality surimi.

Development of an Electric Tugger for Patient Bed Transportation

Chanisa Nimitpanyakul — 2024-12-26

Transporting a patient in a bed within Songklanagarind Hospital, Faculty of Medicine, Prince of Songkla University, typically requires at least two workers. During peak hours, insufficient personnel often overburdens the patient transportation team. To address this challenge, this research aims to develop an electric tugger, or e-tugger, to facilitate patient bed transport. The e-tugger is designed to enable a single staff member to haul a patient bed on flat surfaces and up to a 5% incline to the destination. The e-tugger's design includes an electric tugger and a forklift. The tugger’s structure provides space to install the necessary components. A 3-kW brushless DC motor, powered by 72V, 15Ah Li-ion batteries, drives the system, allowing it to move a patient bed weighing up to 400 kg on a 5% incline. The staff can control the e-tugger's motion using either a control box or a joystick. The forklift, when viewed from the side, has an L-shape and is equipped with an integrated electric scissor jack that lifts the forklift up and down, operated via the control box. The e-tugger’s performance study focuses on two main aspects: (1) the user experience of coupling the e-tugger to the patient bed, and (2) the e-tugger’s operation on a 30-meter flat surface and in a passageway. Onsite testing demonstrates that one staff member can effectively transport a patient in a bed using the e-tugger. Coupling the e-tugger to a patient’s bed takes only 10 seconds. The e-tugger can propel a 255-kg patient bed at approximately 1.66 m/s. The electric motor consumes 2.46 A on a flat surface and 4.46 A on a 5% incline. Additionally, after transporting a 380-kg patient bed for 2.36 km, the battery's state of charge decreases by 2 %, with the e-tugger's average energy consumption rate being approximately 91.5 Wh/ 10 km.

Development of Mobile Application for Disseminating Baan Chin Community’s Local Food and Desserts

Aroonrak Tunpanit — 2024-12-26

Local foods and snacks are local cultural heritages which hold significant value for ongoing conservation. Baan Chin Community in Satun Province is known for its unique local foods and snacks, which are exclusively prepared during important festivals. The application of modern technology in data management allows easy and quick access to all people. It serves as a method for storing and releasing data, including for commercial use. This research aimed to design and develop a mobile application for promoting local foods and snacks of Baan Chin Community. The system was analyzed and designed using “Use Case Diagram” and “Data Flow Diagram”. The application was developed using Glide, Google sheets and Canva. The efficiency and satisfaction of the mobile application were evaluated by five experts. The satisfaction of the application was assessed by a sample group of 300 people, selected using a specific selection method. Statistics used in the data analysis consisted of percentage, mean () and standard deviation (S.D.). The efficiency evaluation result showed that the application was highly effective ( = 4.63, S.D. = 0.529) because it was easy to use and allowed for quick information searches, aligning well with current technology. The result of satisfaction evaluation from the sample group, which tested the application, were divided into 3 areas: 1) Conformity with User Demand received the highest level of satisfaction ( = 4.75, S.D. = 0.545); 2) Application Design received the highest level of satisfaction ( = 4.64, S.D. = 0.532); and 3) Functioning of the Application had the high level of satisfaction ( = 4.48, S.D. = 0.619), respectively. This showed that the application is easy to use, convenient, and fast, meeting the users’ needs. It serves as a channel to preserve the unique identity of local foods and snacks, while also promoting the community’s economy. Furthermore, it has potential to extend into the business sector through electronic commerce to be accessible to the target group for selling community products as intended.

The Effects of Dry Yeast Supplementation on Rumen Ciliated Protozoa Population and Volatile Fatty Acid Production in Lactating Beef Cows

Wiruntita Bohman — 2024-12-26

This present study aims to assess the impact of supplementing dry yeast (Saccharomyces cerevisiae: SC) on ruminal ciliated protozoa and volatile fatty acid production in lactating beef cows. Nine lactating beef cows were divided into three groups: the control group (SC0) received a 16% protein commercial concentrate diet without yeast supplementation at 0.5% of body weight (BW) in kilograms, while the second (SC2) and third (SC4) groups were given the basal diet along with 2 or 4 grams per head/day of SC, respectively, plus 10% BW roughage for 21 days. At the last day of experiment, ruminal fluid was collected at 2 time points (0 and 4 h post-feeding) using rumenocentesis technique. The samples underwent analysis for ruminal pH, ciliated protozoa motility and population, and volatile fatty acids production. Results demonstrated that the SC2 group exhibited a lower pre-feeding ruminal pH compared with the other groups (P < 0.05), whereas the SC4 group displayed reduced protozoa motility (P < 0.05). Although the SC2 group tended to have a higher ciliated protozoa population, this difference was not statistically significant. Total VFA production was significantly elevated in the SC4 group (P < 0.05), and both the SC2 and SC4 groups exhibited increased total VFAs and acetate levels post-feeding. The SC2 group displayed significantly higher acetate:propionate and acetate:butyrate ratios compared to the other groups (P < 0.05). These findings suggest that dry yeast supplementation can modulate rumen fermentation through alterations in protozoal activity and VFA profiles, with potential implications for digestive efficiency and nutrient absorption in lactating beef cows.

The Effect of Vulcanization Temperature on the Properties of Natural Rubber Latex to Prepare the Suturing Training Pad

Korn Taksapattanakul — 2024-12-26

This study focuses on the controlled curing method for preparing natural rubber latex as a suturing training pad. Local natural rubber latex was transformed into pre-vulcanized rubber latex using a chemical. The natural rubber sheets were cured at temperatures of 30 ± 2 °C, 40 ± 2 °C, and 50 ± 2 °C for 7 days under controlled conditions. Various properties, including stress-strain curves, hardness, crosslink density, swelling, and crosslinking behavior, analyzed using FT-IR spectra, were examined. The FT-IR spectra indicated a decrease in the signal of the C=C bond and an increase in the C-S bond, demonstrating the crosslinking behavior. As the curing temperature increased, crosslinking also increased, resulting in enhanced stress-strain properties at break, higher Young's modulus, greater strain hardening, and increased hardness. Additionally, crosslink density increased while swelling decreased. A curing temperature of 30 ± 2 °C was selected for preparing the natural rubber sheet for use as a suturing training pad. The performance of this rubber sheet was tested and compared with a commercial silicone skin suture practice sheet. The results showed that no cracking occurred around the pinholes, and the rubber surface could be sutured without tearing. A nylon suture placed on the rubber surface demonstrated a tight closure, similar to that of the silicone skin suture practice sheet.

Mechanical, Thermal and Barrier Properties of Poly(butylene adipate-co-terephthalate) Biocomposite Films Incorporated with Nano-Calcium Carbonate and Glycerol

Kannika Yimnak — 2025-01-03

This research aims to improve the mechanical, thermal and barrier properties of poly (butylene adipate-co-terephthalate) (PBAT) bioplastic by compounding with nano-calcium carbonate (CaCO₃) and glycerol. Firstly, the compounding pellets were prepared by incorporating 5, 7 and 10 wt% CaCO₃ and 5 parts per hundred of resin (phr) of glycerol using a twin-screw extruder. Then, these pellets were processed into films using blown film extrusion. It found that the addition of 5 wt% CaCO₃ into PBAT (PBAT5C) resulted in increasing tensile strength and melting temperature of PBAT. It can also reduce oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) compared with PBAT films. In addition, the inclusion of 5 phr of glycerol in PBAT5C (PBAT5G5C) improved the dispersion of nano-calcium carbonate within the PBAT film, resulting in substantial improvements in the mechanical, thermal and barrier properties of the PBAT5G5C film compared with the PBAT5C film. Therefore, the PBAT5G5C film is suitable for use as a packaging film for food products that require low OTR and WVTR. This provides an alternative to replace conventional plastics that are difficult to decompose.

Development of Shredded Catfish as a Health Food Product for the Elderly

Rattanakorn Saenthumpol — 2025-01-06

This research aimed to develop shredded catfish products for the elderly by studying physical, chemical, and microbiological qualities, and evaluating sensory attributes. Using 30 people with a 9-point hedonic scale, formula 3 was most accepted, leading to the development of two products: original flavor and seaweed with sesame flavor. Results showed lightness (L*) values of 53.91±1.36 and 50.20±0, red (a*) values of 10.50±0.69 and 11.25±0.51, and yellow (b*) values of 30.23±0.26 and 28.65±0.51, respectively, with significant differences (P<0.05). Water activity values (0.57 and 0.56) were not statistically different (P>0.05). Chemical composition of the original and seaweed with sesame products were, respectively, moisture 4.53% and 4.75%, protein 48.06% and 50.12%, fat 6.54% and 7.35%, carbohydrate 32.64% and 33.52%, and ash 7.47% and 7.54%. Moisture content met standards. Microbiological analysis showed total microbial counts of 2.5x10³ CFU/g (original) and 3x10³CFU/g (seaweed with sesame). Both flossed catfish products contained yeast and mold levels of less than 25 CFU/g, which are within the standard limits.