Recent Science and Technology

Infill Structure Analysis of 17-4 PH Materials Extrusion Additive Manufacturing based on Finite Element Method

Kaweewat Worasaen, Pasut Promsuwan — Tue, 30 Dec 2025 00:00:00 +0700

This study evaluates the mechanical performance of 17-4 precipitation-hardened (PH) stainless steel components fabricated via material extrusion additive manufacturing (MEAM), with a focus on the role of the infill structure. Finite element method (FEM) simulations and tensile testing were used to analyze how different infill patterns and densities affect structural integrity. The results show that increasing infill density improves mechanical strength and load distribution, reducing stress concentrations that lead to failure. A 30% infill density was identified as an effective balance between strength and material efficiency, making it suitable for high-pressure applications. However, this choice may limit weight reduction and material savings compared to lower infill densities. These findings highlight the importance of infill optimization in enhancing the reliability and cost-effectiveness of MEAM-produced 17-4 PH components for engineering use.

House Built with Interlocking Blocks Containing Para-Wood Ash

Tue, 30 Dec 2025 00:00:00 +0700

This research aimed to determine the optimal mixing ratio of rubberwood ash in the aggregate of masonry blocks. The most suitable ratio was selected to construct a prototype house wall using masonry blocks mixed with rubber wood ash. The cement-to-aggregate ratios tested were 1:4, 1:5, 1:6, 1:7, and 1:8 by weight. The aggregate was a mixture of laterite and heavy rubber wood ash in ratios of 100:0, 90:10, 80:20, 70:30, 60:40, and 50:50 by weight of the aggregate. The blocks were molded using a small-scale industrial press. The results were compared to the Community Product Standard 602/2547, which specifies that the compressive strength of non-load-bearing masonry blocks must be at least 25 kg/cm², while load-bearing blocks must have a compressive strength of at least 70 kg/cm² and a water absorption rate not exceeding 288 kg/m³. All ratios met the criteria for non-load-bearing blocks, while only 11 ratios met the standard for load-bearing blocks. These included a cement-to-aggregate ratio of 1:4 with aggregate mixed with 0, 10, 20, 30, 40, and 50 percent of rubberwood ash; a cement-to-aggregate ratio of 1:5 with aggregate mixed with 0, 10, 20, and 30 percent of rubberwood ash; and a cement-to-aggregate ratio of 1:6 with aggregate mixed with 0 percent of rubberwood ash. Therefore, the cement-to-aggregate ratio of 1:8 with 50% heavy rubberwood ash was the most suitable ratio for constructing a prototype house wall. The resulting blocks exhibited a maximum heat resistance of 2.0 degrees Celsius, were 60% cheaper than commercial products, did not develop mold or mildew, and had no odor of rubberwood ash. The masonry blocks mixed with rubberwood ash could be successfully used to construct residential walls and were deemed a practical building material. This innovative building material offers a cost-effective solution and effectively converts industrial waste into a valuable product.

Feature Analysis of Current Unbalance in Electrical Distribution Systems Using Random Forest

santi karisan, Sittisak Rojchaya — Tue, 30 Dec 2025 00:00:00 +0700

The building sector accounts for more than 130 exajoules (EJ) of global energy consumption, representing approximately 30% of the total energy demand, with a continuous upward trend. Notably, energy demand in buildings surged during the COVID-19 crisis and increased by approximately 20% between 2000 and 2007. A significant portion of this energy consumption is attributed to lighting and air-conditioning systems. The rising electricity demand in buildings adversely impacts power quality, leading to issues such as harmonic distortion, voltage unbalance, and current unbalance in electrical distribution systems. This study investigates the application of the Machine Learning-based Random Forest Regressor model to analyze the causes of current unbalance in a building’s power distribution system. A case study was conducted using electricity consumption data from a facility at the College of Industrial Technology and Management, Rajamangala University of Technology. The analysis results indicate that power features significantly influence current unbalance, with Power Phase A contributing the most at 74.73%, followed by Power Phase C at 10.98% and Power Phase B at 9.55%. These findings provide valuable insights for optimizing maintenance strategies and improving the efficiency of building power distribution systems.

RMUTTOBot: Transforming University Admission Services with a TAG-based RAG LLM Chatbot

Vipa Thananont, Saowakhon Nookhao — Tue, 30 Dec 2025 00:00:00 +0700

Advancements in artificial intelligence, particularly in large language models (LLMs) and retrieval-augmented generation (RAG) techniques, have improved chatbot capabilities for more natural and domain-specific interactions. However, conventional RAG systems, which retrieve information from unstructured text sources like websites and PDFs, exhibit critical failures when applied to the dynamic and precise nature of university information. This research addresses these gaps through the design and development of RMUTTOBot, a domain-specific chatbot providing admissions support for prospective students at Rajamangala University of Technology Tawan-ok (RMUTTO).
We propose a novel, lightweight table-augmented generation (TAG) approach that combines a curated, updatable knowledge base for general information with live database queries for real-time, dynamic data. Performance was evaluated using both automated metrics and human assessments across six criteria: semantic similarity, retrieval effectiveness, relevance, fluency, coverage, and consistency. Experimental results show that the TAG-based RAG system significantly outperformed both the baseline LLM-only configuration and PDF-based RAG system, achieving a 12.76% higher BERTF1 score compared to a PDF-based RAG. Human evaluation confirmed the system’s high response relevance and linguistic fluency, with strong inter-rater reliability (Krippendorff’s α > 0.835). These findings demonstrate that combining structured data augmentation with RAG substantially enhances chatbot accuracy, contextual grounding, and completeness, offering a robust framework for intelligent conversational systems in academic domains. The source code and implementation details are publicly available at https://github.com/vipa-thananant/RMUTTOBot.

Implementation of Lean Principles and QR Code Technology to Enhance Durable Articles Management System at Rattaphum College: A Process Efficiency Analysis

Wanpracha Nuansoi, Supawadee Mak-on, Supachai Maduea — Tue, 30 Dec 2025 00:00:00 +0700

Rattaphum College, Rajamangala University of Technology Srivijaya, previously managed its durable articles through a document-based system, leading to frequent issues such as data loss, redundancy, and difficulty in searching and editing information. This research aimed to (1) develop a durable articles management application using QR Code technology, (2) analyze operational efficiency after applying lean principles, and (3) assess user satisfaction with the new system. The research was conducted using lean principles to reduce steps and time in the operation. The efficiency was calculated from the ratio of total working time to the sum of valuable time. The developed application includes features for QR Code scanning, searching, adding, and editing durable articles, as well as user management. Results showed that, for staff, the application reduced work processes by one step, saved 12.84 minutes, and increased efficiency by 56%. For general users, work steps were reduced by three, with the same time savings and a 72.22% increase in efficiency. User satisfaction was also evaluated, with application design receiving a very good rating ( = 4.50, S.D. = 0.70), and overall system usability rated as good ( = 4.46, S.D. = 0.69). The study also revealed that an easy-to-use user interface design and the perceived usefulness of the system are important factors influencing its acceptance. This system demonstrates significant improvements in efficiency and usability and can serve as a model for implementation in other educational institutions with similar needs.

Impact of Stocking Density on Bioeconomic Performances of Blue Swimming Crab (Portunus pelagicus) Culture in Grow-Out Ponds

Vutthichai Oniam, Wasana Arkronrat — Tue, 30 Dec 2025 00:00:00 +0700

The blue swimming crab (BSC) is a commercially important species with high consumer demand, but escalating exploitation has negatively impacted its natural populations. Establishing effective cultivation methods for BSC offered a promising long-term solution to this issue. This study aimed to enhance stocking density in grow-out ponds by analyzing the effects on bioeconomic performance of BSC farming. The research involved rearing juvenile BSC in 1,600 m² earthen ponds at three stocking densities: low (1 crab/m²), medium (3 crabs/m²), and high (5 crabs/m²). Each group had three replicates (n = 3). BSC were fed an artificial shrimp feed (38% protein) at 5% of body weight per day, with feedings occurring twice daily. Over a 90-day period, survival rate (SR), weight gain (WG), average daily growth (ADG), specific growth rate (SGR), and feed conversion ratio (FCR) were assessed, alongside economic metrics such as total revenue (TR), break-even point (BEP), and payback period (PBP). Results indicated that stocking density significantly (p<0.05, one-way ANOVA) influenced the SR, WG, ADG, SGR, and revenue in BSC cultivation. As density increased, SR declined, and higher densities resulted in lower growth rates, reduced TR, and elevated FCR. In terms of culture efficiency, the densities of 1 and 3 crabs/m² proved to be more suitable for BSC culture compared to 5 crabs/m². However, economically, it was determined that rearing BSC at these three densities was not a worthwhile investment, with the density of 5 crabs/m² having the highest BEP (1.08 kg/m²) and PBP (7.5 years), while 1 crab/m² had the lowest BEP (0.38 kg/m²) and PBP (3.9 years). Therefore, appropriate BSC rearing guidelines should consider a density of no more than 3 crabs/m² for future production.

Encapsulated Freeze-Dried Lactic Acid Bacteria Enhance Immune Response and Support Growth of Penaeus monodon (Fabricius, 1798) in Hatchery and Earthen Pond Culture

Tue, 30 Dec 2025 00:00:00 +0700

This study investigated the effects of dietary supplementation with freeze-dried encapsulated Lactobacillus spp. (FEL) on the immune response, intestinal microbiota, and growth performance of black tiger shrimp (Penaeus monodon) under both hatchery and pond conditions. FEL, prepared with four lactic acid bacteria (LAB) strains and encapsulated in sodium alginate, was incorporated into diets at concentrations of 0%–1.0% (w/w). In hatchery trials, juvenile shrimp fed FEL-supplemented diets (0.2–1.0%) exhibited significantly enhanced total hemocyte count, phenoloxidase activity, and clearance of Vibrio parahaemolyticus, achieving 100% survival compared with 82.22 ± 8.02% in controls (p < 0.001). Shrimp fed 0.2% FEL also showed a significantly higher specific growth rate (1.94% day^-1) compared with controls (1.33% day^-1, p < 0.05). Moreover, FEL supplementation promoted LAB colonization and reduced intestinal Vibrio densities. In pond trials, shrimp were cultured for 100 days, with growth monitoring conducted from day 60 to day 100. Microbiota analysis by 16S rRNA gene sequencing revealed an increased abundance of beneficial Firmicutes and Phaeobacter inhibens and a decreased abundance of Proteobacteria and Photobacterium damselae in FEL-fed shrimp. Shrimp receiving 0.2% FEL supplementation also exhibited consistently greater body weight and length than the control group, with significant differences observed at later sampling points (p < 0.05). These findings demonstrate that FEL supplementation can enhance innate immunity, modulate the gut microbiota, and promote shrimp growth, highlighting its potential as a sustainable probiotic feed additive for shrimp aquaculture.

Impact of Seaweed Species and Density on Mitigating Cannibalism in Blue Swimming Crab (Portunus pelagicus) Juvenile

Chonlada Leearam, Rungtiwa Konsantad, Wasana Arkronrat — Tue, 30 Dec 2025 00:00:00 +0700

Cannibalism poses a major challenge in the aquaculture of crustaceans, particularly during the early nursery stages of the blue swimming crab (Portunus pelagicus), an economically important species that often experiences high mortality rates due to this behavior. This study investigated the effects of varying densities of Caulerpa lentillifera (CL), and Chaetomorpha crassa (CC), two green seaweed species, on reducing cannibalism in juvenile C2-stage crabs during their nursery phase. A two-factor experimental design was applied to crabs reared in controlled-environment indoor tanks for 30 days, based on seaweed density (0.5, 1, and 2 kg/m²) and species presence, with a negative control group lacking shelter. Based on the findings, while the seaweed species did not significantly influence growth parameters, the density of 0.5 kg/m² promoted higher growth rates, although these were not significantly different from the negative control. Conversely, the 2 kg/m² density of CC resulted in a substantial reduction in cannibalism, particularly from day 20 onward, with the lowest mortality rates observed under this treatment. These results underscore the importance of optimizing seaweed density and species type to enhance survival rates in crab juveniles, suggesting that CC at 0.5 kg/m² was optimal for growth, while CC at 2 kg/m² was most effective in minimizing cannibalism.

Efficacy of Ethanol Extract of Leftover Chili (Capsicum annuum var. frutescens L.) on Weed Control, Growth and Yield of Thai Eggplants (Solanum xanthocarpum Schrad. & Wendl.)

Nalin-on Nuiplot — Tue, 30 Dec 2025 00:00:00 +0700

Weeds pose major problems for farmers as they compete for essential factors for plant growth, thereby affecting crop yields. Currently, natural methods are increasingly popular for weed control. In the study area where vegetables like chili and eggplant are grown for consumption and sale, a significant weed problem in the eggplant plots led to low quality and insufficient yields. This prompted the researcher to investigate using leftover chili extract to control weeds. This study aimed to evaluate the efficacy of ethanol extracts of leftover chili in controlling weeds. The extract was prepared using a 70% ethanol solution, filtered to separate pulp, then diluted with water to a 30% alcohol concentration, and poured into a spray bottle. Three treatment groups were tested: Control Group 1 (pulling weeds by hand), Control Group 2 (spraying with 30% ethanol), and Experimental Group (spraying with chili extracts). Treatments were applied around the base of eggplant plants every 10 days for 90 days. The growth of both Thai eggplant and weeds was measured by assessing height above the soil surface, counting weed growth, and counting eggplant fruit after spraying. Statistical analyses included mean and analysis of variance. The results showed that the chili extract significantly reduced weed germination and growth (dry weight), performing comparably to manual weeding. Notably, eggplant yields in the chili extract group were the highest, significantly outperforming the ethanol control and matching manual weeding. This indicates the extract's potential for effective, chemical-free weed control that supports crop growth.

Growth Performance of Green Oak, Red Oak, and Green Cos in a Deep Flow Technique Hydroponic System

Poonnanan Phankaen, Warawut Kumpanuch — Tue, 30 Dec 2025 00:00:00 +0700

This study examined the growth performance and economic returns of three types of salad vegetables grown in a closed greenhouse using a deep flow technique (DFT) hydroponic system and adjusted to an electrical conductivity (EC) of 1.2–1.8 mS/cm and a pH of 5.6–6.5. The solution contained two balanced stock solutions: Stock A (N, P, K, Mg, S, Mo, B, Zn, Cu, and Mn) and Stock B (Ca and Fe). The study was conducted in Non Mak Khaeng, Watthana Nakhon, Sa Kaeo, Thailand, from March to April, 2024, utilizing a completely randomized design (CRD) with salad vegetable types as the treatment factor. Three lettuce varieties were tested: Green Oak, Red Oak, and Green Cos, with five replications of 10 plants each. The results revealed that Green Cos exhibited the highest growth performance in terms of root length (30.97 ± 0.32 cm), canopy height (19.33 ± 0.25 cm), and weight per plant (162.40 ± 5.29 g), with statistically significant differences (p<0.05) compared with Green Oak and Red Oak. However, Green Oak was recorded for the highest number of leaves (22.00 ± 1.00 leaves per plant). Survival rates were consistent at 100% across all three types. From an economic perspective, Green Cos yielded the highest profit of 4,872.54 THB, followed by Green Oak and Red Oak with profits of 4,526.94 THB and 3,867.88 THB, respectively. This research can be applied to the planning of salad vegetable production in a DFT hydroponic system to align with market goals. For example, it can help increase yields to meet the demands of health-conscious consumers, enhance competitiveness in the market, and ensure stable long-term income. Additionally, this approach supports the development of sustainable agricultural practice.

Effects of Seed Soaking in Cucumber and Carrot Aqueous Extract on Germination and Vigor of Rice Seeds

Pharadee Saeung — Tue, 30 Dec 2025 00:00:00 +0700

Rice seed production in Thailand faces problems related to poor seed quality, resulting in yields not meeting farmers' expectations. This research studies the effects of soaking rice seeds in cucumber and carrot extracts prior to planting on their germination and vigor qualities. The hypothesis for this pre-treatment is that the technique could enhance seeding growth and increase their average yield. The rice seed variety tested was RD49. The experiment consisted of eight treatments: (1) no soaking, (2) soaking in distilled water, (3) soaking in 10% cucumber aqueous extract, (4) soaking in 20% cucumber aqueous extract, (5) soaking in 30% cucumber aqueous extract, (6) soaking in 10% carrot aqueous extract, (7) soaking in 20% carrot aqueous extract, and (8) soaking in 30% carrot aqueous extract. The results showed no statistical differences in terms of germination percentage among eight seed soaking treatments. However, soaking in 20% cucumber aqueous extract (treatment 4) improved seed vigor. The seedling growth rate (8.83 mg/plant) under this treatment was higher than that of treatments (1) and (2), in which the seeds underwent no treatment and were soaked in distilled water. Seedling growth, measured in terms of plant length (7.52 cm) and root length (8.52 cm), was highest in treatment (4) compared with all other treatments (1-3 and 5-8).

Application of Silver/Carbon-based Composite Nanofiber Membrane for Improvement of Microfiltration System

Tanayt Sinprachim, Kattinat Sagulsawasdipan, Somchai Sonsupap — Tue, 30 Dec 2025 00:00:00 +0700

In this study, silver-reinforced carbon nanofiber membranes (CNF@Ag) were fabricated through a binder-free extrusion process. A precursor mixture of carbon nanofibers (CNF) and silver nitrate (AgNO₃) was extruded at 40 MPa, followed by sintering at 800°C in an argon atmosphere for 4 hours to enhance the membrane structure. The physical properties of the CNF@Ag membranes, including porosity, wettability, morphology, and microfiltration efficiency, were systematically analyzed. The results demonstrated that the CNF@Ag membranes exhibited effective microfiltration properties with pore sizes ranging from 9.21 to 21.99 nm. These membranes achieved a turbidity removal efficiency of up to 92.69%, indicating their potential as an effective pre-treatment step for seawater desalination. This study highlights the promising application of CNF@Ag membranes in water purification processes, particularly for turbidity removal in desalination systems.

Characterization of Soluble Polysaccharides from Coconut Residue of Virgin Coconut Oil Production

Viriya Nitteranon, Ananthaya Sansawat — Tue, 30 Dec 2025 00:00:00 +0700

This study aimed to explore the potential of soluble polysaccharides extracted from defatted coconut residue (DCR) as a prebiotic. Our findings reveal that the defatting process of coconut residue (CR) changes its chemical composition of coconut residue in terms of moisture content (7.04 ± 0.04%), fat (3.99 ± 0.55%), protein (2.93 ± 0.18%), ash (0.76 ± 0.04%), and carbohydrate contents (46.58 ± 1.05%). The percentage of soluble polysaccharide was 2.50 ± 0.40. The extraction of soluble polysaccharides (SP) from DCR resulted in increased total sugar contents and non-reducing sugars. Structural analysis of SP by Fourier transform infrared (FT-IR) analysis showed a predominantly polysaccharide composition. High performance liquid chromatography (HPLC) analysis further identified mannose (27.87%) and glucose (25.00%) as the major monosaccharides present in SP. Remarkably, SP exhibited stronger resistance (92.42% resistance) to acidic condition in the human stomach compared to inulin (25.52% resistance) at pH 1. Furthermore, SP demonstrated prebiotic properties by promoting the growth of Lactobacillus acidophilus TISTR 2365. These findings confirmed the promising prebiotic properties of coconut residue after cold-pressed coconut oil processing, which may be used as an ingredient in functional foods and nutraceutical products.

Effects of Cannabis (Cannabis sativa L.) Leaf Supplementation in Broiler Diets on Growth Performance, Carcass Characteristics, and Meat Quality

Tue, 30 Dec 2025 00:00:00 +0700

This study investigated the effects of supplementing broiler diets with Cannabis sativa L. leaves on growth performance, carcass characteristics, and meat quality. A total of 150 unsexed broiler chicks (aged 7 days) were randomly assigned to five dietary treatments with three replicates per treatment and 10 birds per replicate. The treatments included a control group fed a basal diet and four experimental groups receiving the basal diet supplemented with 0.5%, 1%, 1.5%, and 2% cannabis leaf powder, respectively. The birds were raised in an open-house system with ad libitum access to feed and water throughout the trial. The results showed that cannabis leaf supplementation had no significant effect on feed intake and feed conversion ratio (FCR) (P > 0.05). However, supplementation at 0.5% significantly increased final body weight and average daily gain (ADG) (P < 0.01), while the 2% supplementation level resulted in a significant reduction in these parameters (P < 0.01). Regarding carcass characteristics, the 0.5% supplementation level increased the percentage of breast and tenderloin yields (P < 0.01), whereas the 2% level reduced neck yield (P < 0.05). Meat quality parameters, including pH, water-holding capacity, and sensory attributes, were unaffected by dietary cannabis supplementation (P > 0.05). However, the 1% supplementation level resulted in a significantly higher b* value in drumstick meat (P < 0.05). In conclusion, supplementing broiler diets with 0.5% cannabis leaf powder may enhance growth performance and improve carcass characteristics without negatively affecting meat quality. Further studies are recommended to determine the optimal inclusion level for practical applications in poultry nutrition.

Effects of Roughage Feeding Strategies on Growth Performance Carcass Quality and Fatty Acid Composition in Meat Goats

Tue, 30 Dec 2025 00:00:00 +0700

This study aimed to compare the effects of three different roughage sources—Leucaena (Leucaena leucocephala), Pakchong 1 Napier grass (Pennisetum purpureum × Pennisetum americanum), and Pangola grass (Digitaria eriantha) in combination with concentrate supplementation on production performance, carcass quality, and fatty acid composition in meat goat. The experiment was conducted using a completely randomized design (CRD) involving nine male goats (50% Thai Native × Boer crossbred), approximately four months old, with an average initial body weight of 17.94 ± 1.5 kg. The animals were randomly allocated into three treatment groups (n = 3 per group), each receiving one type of freshly cut roughage ad libitum (Leucaena, Pakchong 1 Napier grass or Pangola grass) and supplemented with a 14% crude protein concentrate at 1.5% of body weight. The results indicated that goats fed Leucaena leucocephala combined with concentrate exhibited the highest dry matter digestibility, body weight gain, and omega-3 fatty acid accumulation, indicating that Leucaena is the most effective roughage source under the present experimental conditions. Nevertheless, both Pakchong 1 Napier grass and Pangola grass proved to be suitable and sufficient alternatives for goat feeding, particularly in areas where these grasses are readily available. Additionally, these forages contributed to the accumulation of omega-6 (C18:2) fatty acids, which are known to help maintain normal cell function, support immune responses, and reduce the risk of cardiovascular disease when consumed in balanced proportions.