YRU Journal of Science and Technology

Bioaerosols and the Indoor Air Quality of a University Library in Surat Thani Province

Thu, 11 Dec 2025 00:00:00 +0700

Indoor air quality plays a crucial role in the health and well-being of individuals working within a building. This study presents a cross-sectional descriptive investigation aimed at evaluating indoor air quality and the presence of microorganisms, as well as exploring the correlation between microorganism levels and air quality within the library building of a university in Surat Thani Province, Thailand. The study included biological measurements of indoor air pollution, specifically total bacteria and fungi, alongside assessments of chemical factors (carbon dioxide and carbon monoxide) and thermal comfort (temperature and relative humidity). A selection of sampling sites was established, and measurements were conducted over four weeks, with two consecutive days of sampling each week. The collected data underwent analysis using descriptive statistics, analysis of variance, and correlation coefficients. The findings indicated that the levels of temperature, carbon dioxide, carbon monoxide, total bacteria, and fungi within the library building fell within the acceptable limits defined by the Department of Health guidelines. However, the relative humidity ranged from 47.3 to 82.3 percent, averaging 68.5±6.5 percent, which did not meet the recommended criteria of 50-65 percent. There were no significant correlations found between bioaerosols and temperature, relative humidity, CO₂, and CO levels (p>0.01). Additionally, the microbiological assessment of the library services indicated a statistically significant difference in the levels of bacteria and fungi (p< 0.05). The indoor-to-outdoor (I/O) ratios for carbon dioxide and bacteria were 1.3 and 1.2 times, respectively, indicating an inadequacy in ventilation from the inside of the building to the outside. Therefore, it is imperative for the library to enhance ventilation to lower humidity, carbon dioxide, and bacterial counts, while also ensuring ongoing monitoring and maintenance of indoor air quality.

Selection of Krathue (Zingiber zerumbet (L.)) Varieties in the Southern Region for the Production of Unique Flowering Plants and their Use as Herbal Tea

Thu, 11 Dec 2025 00:00:00 +0700

Zingiber zerumbet, commonly known as Krathue, is a native plant of Southern Thailand, traditionally utilized as a spice, medicinal herb, and ornamental cut flower. However, most research has focused on breeding, production, and pharmacological studies. Therefore, the objectives of this research were to study Krathue varieties in Southern Thailand with potential to be a commercial local identity plant and add economic value by processing it into herbal tea products. It was found that Krathue Pilas and Kratheu Phee have potential as cut flowers, while Krathue Phrao is a species with potential for processing to create added value. The chemical analysis of the bracts and rhizomes of Krathue Phrao showed a pH of 5.78 and 6.33, soluble solids content of 0.009 and 0.057 °Brix, total phenolic compound content of 5.48 and 4.44 mg gallic acid equivalents per gram of dry weight, and high antioxidant activity by DPPH method of 68.34 and 61.85%, respectively. In addition, the bracts contained 1.83 percent fiber content on fresh weight. When developed into herbal tea products using a combination of bract powder, rhizome powder, and oolong tea powder in different ratios, the resulting products showed statistically significant differences in both physical and chemical aspects (p ≤ 0.05). The third experimental set, using mixed powders of bracts, rhizomes, and oolong tea at a ratio of 1:0.25:0.75, was the most suitable, with the highest overall preference score of 7.17 points. It also had the highest total phenolic compound content and antioxidant activity.

The Enhancement of Biogas Production from Food Waste by Using Two-stage Upflow Anaerobic Sludge Blanket (UASB) Reactor at Mesophilic Temperature

Patcharee Intanoo, Kanjana Somrit — Thu, 11 Dec 2025 00:00:00 +0700

At present, the demand for energy is increasing, particularly for fossil fuels, which contrasts with the limited availability of natural resources. To sustainably meet this growing demand, alternative energy production technologies with properties similar to fossil fuels have been developed. One such technology is the production of biogas from food waste using a two-stage upflow anaerobic sludge blanket (UASB) reactor under mesophilic conditions, maintained at a constant temperature of 37°C and a pH range between 4.50–7.50 with a recycle ratio at 1:1. The study on biogas production from food waste using the two-stage UASB reactor was operated at different COD loading rate ranging from 10.54 to 26.40 kg/m³d based on working volume of 5 liter and 8.10 to 21.60 kg/m³d based on working volume of 16 liter. From the study, it revealed that at an optimal COD loading rate of 21.07 and 18.90 kg/m³d based on working volume of 5 and 16 liter, respectively, the system gave the highest methane production performance. It performed in term of the maximum methane production rate of 33.85 ml/d, with a specific methane production rate of 1.58 ml CH₄/l d (or 4.19 ml CH₄/g bacteria d) and a maximum methane yield of 0.114 ml CH₄/COD_applied (or 2.38 ml CH₄/COD_removed). This is corresponding to the maximum COD removal of 45.14 %.

Comparisons of Mycelial Growth of Oyster Mushroom (Pleurotus spp.) on Culture Media and Sorghum Grain Spawn in Relation to Yield from Commercial Spawn Sources in Thailand

Somthob Wetosot, Suthep Wacharawetsaringkharn — Thu, 11 Dec 2025 00:00:00 +0700

Oyster mushroom (Pleurotus spp.) is widely cultivated for commercial purposes. However, genetic variation among strains from different production sources in Thailand leads to differences in yield performance. This study aimed to compare the mycelial growth and yield potential of oyster mushroom strains from 10 commercial sources in Thailand. Mycelial growth was evaluated on PDA medium, sorghum grain, and rubberwood sawdust substrate by recording colony diameter on PDA and sorghum grain, mycelial length on the substrate, mycelial dry weight, and mycelial density. Yield performance was assessed based on fresh mushroom weight and the number of fruiting bodies per cluster. The experiment was conducted using a completely randomized design (CRD), and means were compared using Duncan’s Multiple Range Test (DMRT). The results showed that strains from DOA and WTN MF-RYG exhibited the highest colony diameters on PDA (87.43 mm and 86.87 mm, respectively). On sorghum grain, the DOA strain showed the highest mycelial growth (96.77 mm). In terms of dry weight, strains from DOA, SP MF-CMI, SRY MF-LEI, and SHP-TAK were among the highest performers (10.02–5.99 g). Regarding yield, strains from DD MF-SKA, SP MF-CMI, SRY MF-LEI, SHP-TAK, WTN MF-RYG, NKP LM-NPT, PP MF-PCT, and CB MF-RBR produced high fresh weights (67.42–56.57 g) and a large number of fruiting bodies per cluster (19.67–9.33 mushrooms/cluster). Overall, the DOA strain demonstrated the best performance across all parameters. Additionally, strains from SHP-TAK, SRY MF-LEI, and SP MF-CMI exhibited rapid mycelial colonization on the substrate and good yield potential, making them suitable for commercial cultivation. These findings provide practical guidance for selecting and developing oyster mushroom strains that meet the specific needs of commercial producers.

Carbon Footprint Assessment of Local Administrative Office: A Case Study of Bannang Sata Subdistrict Administrative Organization, Yala Province

Narumol Phantaweesub, Arif Cheseng, Maytiya Muadchim, Hafsah Chesoh — Thu, 11 Dec 2025 00:00:00 +0700

Natural disasters are becoming increasingly severe, primarily due to human-induced greenhouse gas emissions, causing significant impacts on life and property. This study aimed to assess the carbon footprint and propose strategies to reduce greenhouse gas emissions of the Bannang Sata Subdistrict Administrative Organization, Yala Province. The assessment was conducted across three scopes, with refrigerant leakage of R-22 considered separately, following the guidelines of the Thailand Greenhouse Gas Management Organization, and data were collected from January to December 2023. The total carbon footprint was 51.42 tCO₂e, with electricity consumption in Scope 2 contributing the most 41.87 tCO₂e (81.39%), followed by Scope 1 8.69 tCO₂e (16.90%) and Scope 3 0.86 tCO₂e (1.71%). Refrigerant leakage of R-22 accounted for 152.41 tCO₂e (74.76% of all activities). Replacing conventional lighting with LED bulbs could reduce the organization’s greenhouse gas emissions by 49%, with a payback period of 10 months. Installing rooftop solar panels was identified as a cost-effective long-term investment. Additionally, switching the refrigerant to R-32 could save up to 48.89 kWh per year, or alternatively using R-290, which has comparable efficiency but a global warming potential (GWP) 550 times lower than the original refrigerant. Establishing a data recording system and expanding assessment activities to align with evaluation guidelines can enable the organization to assess its carbon footprint more effectively, supporting the achievement of future greenhouse gas emission reduction targets.

Effect of Physiological Maturity on Hybrid Sunflower Seed Quality

Thu, 11 Dec 2025 00:00:00 +0700

Appropriate timing of seed harvesting is a crucial factor in producing high quality hybrid sunflower seeds. Specifically, harvesting during the physiological maturity stage, when seeds reach their highest dry weight and germination potential, is considered optimal. Proper timing of seed harvest is a critical factor in obtaining high-quality seeds, particularly at the stage of physiological maturity. This study aimed to determine the appropriate harvest time to obtain the best seed quality. The experiment was conducted at the Faculty of Agriculture, Rajamangala University of Technology Srivijaya, Thung Song District, Nakhon Si Thammarat Province, from May to July 2022, using a Completely Randomized Design (CRD) with four replications. The treatments consisted of five harvest times: 10, 20, 30, 40, and 50 days after flowering (DFA). Flowering dates were marked using different colored threads tied to the heads. Physical and seed quality traits were evaluated. The results revealed statistically significant differences (p ≤ 0.01) among all traits. The best results were obtained at 40 DFA, when sunflower heads showed 50% light brown and 50% dark brown coloration. Seed moisture content before and after drying was 17.00% and 8.33%, respectively. The 100-seed weight was 6.84 grams, germination was 84.75%, soil emergence was 78.25%, field emergence was 74.00%, and mean germination time was 4.32 days. Therefore, harvesting at 40 DFA is the most suitable stage for obtaining high-quality seeds of the hybrid sunflower cultivar Pacific Aquara 6.