Thai Science and Technology Journal

Utilization of Eco-Friendly Hydraulic Cement in High-Strength Concrete-Filled Rectangular Steel Tubular Columns

Tue, 25 Jun 2024 00:00:00 +0700

This research focuses on studying the structural behavior of high-strength concrete-filled rectangular steel tubular columns with hydraulic cement under axial compression, and comparing them with high-strength concrete-filled steel tubular columns using Portland cement. The main parameters used in this study were the types of cement, curing time of concrete, and wall thicknesses of the steel tube. A total of 24 column specimens were tested under continuously increasing axial load until reaching their failure. The test columns were examined to determine their structural behavior, axial capacity, and key influencing parameters. From the tests, it was found that the response curves of the high-strength concrete-filled steel tubular columns exhibited linear elastic behavior up to approximately 90-95% of their maximum load capacity. Subsequently, the observed behaviors of the columns exhibited nonlinearity and high deformation before failure. The columns’ nonlinear behavior was of the strain-softening type. The failure modes of the specimens initiated with the occurrence of concrete cracks, followed by localized buckling of the steel tube wall. Furthermore, when comparing the experimental findings with the results derived from the ACI design equations, it can be concluded that the ACI design equations are suitable for predicting the maximum load of the high-strength concrete-filled steel tubular columns with hydraulic cement. Finally, the utilization of hydraulic cement has the potential to efficiently substitute Portland cement. Hydraulic cement is one approach that may contribute to significantly minimizing carbon dioxide emissions.

Cannabinoids Extraction from Cannabis Cultivar Blueberry by Pulsed Electric Field

Tue, 25 Jun 2024 00:00:00 +0700

The aims of this study were to define the optimum conditions for pulsed electric field extraction of delta-9-tetrahydrocannabinol (THC) and total cannabinoids of the Cannabis sativa L. (Blueberry variety) and to apply the response surface method to design a Box Behnken experiment to investigate the effects of three independent variables: pulse numbers at levels 100-300, pulse intensity at 5-10 kV/cm, and the solution ratio at 1:20-1:40. The best yield result was then compared with the traditional maceration extraction method. The experiments found that the optimum conditions for extracting THC and total cannabinoids were 300 pulses, a pulse intensity of 7.5 kV/cm, and a solution ratio of 1:20. The maximum THC content was 254.77±11.01 mg/g, and the total cannabinoids content was 270.98±11.96 mg/g, which were higher than those obtained by maceration by 20.13% and 22.69%, respectively. Moreover, the extraction time was significantly shorter, by 88.9%. Therefore, the extraction of cannabinoids using the pulsed electric field technique can be an effective method for extracting high-value phytochemicals from cannabis, offering both efficiency and higher quality.

Properties Evaluation of Natural Sea Water for Biodegradation Test According to ASTM D6691

Tue, 25 Jun 2024 00:00:00 +0700

The evaluation of the properties of natural seawater for a biodegradation test in accordance with ASTM D6691 was performed by utilizing seawater from the eastern coast of Thailand, specifically Chonburi Province (CB) and Rayong Province (RY). Samples were collected three times throughout the year: in November 2021, March, and July 2022. The results indicated that, over the study period, the average biodegradation percentages of the positive reference substance (cellulose chromatography grade) in both seawater samples ranged from 72.90% to 94.33% within the 28-day test period. This range aligns with the criteria outlined in ASTM D6691, which specifies that the biodegradation value of the positive reference substance must exceed 70% within the 10 to 90 days period. In conclusion, both sources of natural seawater exhibit properties suitable for assessing biodegradation according to ASTM D6691. For the upcoming study, the collection area for seawater will be expanded to validate the test method and provide evidence of its accuracy and reliability in the biodegradation testing of plastics in seawater.

Efficiency of Thai Herbal Extracts from Thai Traditional Medicine Recipe Against Human Pathogenic Microorganisms and Antioxidant Activity

Pattrawadee Ronghin, Foy Kaewsathian, Preuttiporn Supaphon — Tue, 25 Jun 2024 00:00:00 +0700

This research aims to evaluate the potential of extracts for antimicrobial and antioxidant activities from five medicinal plants used in a Thai traditional medicine recipe. Furthermore, the total phenolic and total flavonoids content were analyzed using the Folin Ciocalteu method and colorimetric aluminum chloride method, respectively. The five plants (Smilax corbularia, Smilax glabra, Stemona tuberosa, Melodorum siamense, Canna indica) were extracted with ethanol and ethyl acetate. Ten extracts were evaluated for their antimicrobial and antioxidant activities using a colorimetric broth microdilution test and DPPH radical scavenging assays, respectively. Ten human pathogenic microorganisms were used in the antimicrobial test: Staphylococcus aureus ATCC25923, Methicillin resistant Staphylococcus aureus (MRSA) SK1, Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853, Candida albicans ATCC90028, Candida albicans NCPF3153, Cryptococcus neoformans ATCC90112, Cryptococcus neoformans ATCC90113, Microsporum gypseum and Taralomyces marneffei. The ethanol extract from M. siamense was the most active against P. aeruginosa and M. gypseum with minimum inhibitory concentration (MIC) of 0.4 mg/ml, followed by the ethanol extract from S. corbularia against S. aureus with an MIC of 0.8 mg/ml. The ethanol extract from S. corbularia had the strongest antioxidant activity (DPPH) with an IC50 of 3.08 ± 0.49 μg/ml. In addition, these active extracts were tested for total phenolic and total flavonoids content. They were found to contain high amount of total phenolics at 403.53 ± 0.83 mg of gallic acid equivalent/g extract and total flavonoids at 21.23±0.16 mg QE/g of extract. These results indicate that extracts from Thai herbals are promising as they are a good source of many active metabolites for future applications.

Seed Priming with KNO3 Solutions on Seed Quality of Asiatic Pennywort

Tue, 25 Jun 2024 00:00:00 +0700

Seed dormancy of Asiatic pennywort is caused by germination inhibitors in the embryo or food storage inside the seed at the physiological maturity stage, resulting in poor, slow and non-uniform germination. Therefore, this research aimed to study the effects of seed priming with KNO₃ solutions on the seed quality of Asiatic pennywort to enhance seed germination. The experiment was designed in a completely randomized design comprising six treatments, including non-primed seeds (control), and seed primed by soaking in 0% (reverse osmosis water), 0.5, 1, 2 and 3% KNO₃ solutions for 24 hours. Seeds were then dried to reduce the moisture content to the initial level (7%). The results showed that seed priming of Asiatic pennywort with all treatments had no effect on the percentages of radicle emergence and germination compared to non-primed seeds. However, it did reduce the days to emergence (DTE) and mean germination time (MGT) compared to the control. Therefore, seed priming of Asiatic pennywort with 1% KNO₃ for 24 hours was the best method, resulting in higher germination rate, and faster DTE and MGT compared to non-primed seeds.

Antioxidant Properties of Barringtonia acutangula Gaerth. Leaf Tea with Different Drying Methods and Brewing Conditions

Tue, 25 Jun 2024 00:00:00 +0700

This research aimed to investigate the effects of different drying methods (hot-air drying and roasting), soaking temperatures (60, 70, 80 and 90^oC), and brewing times (0, 2, 4, 6, 8 and 10 minutes) on the antioxidant properties of Barringtonia acutangular Gaerth. leaf tea. It was found that B. acutangular leaf tea dried using hot-air oven had less degradation of antioxidant properties compared to roasting. Increasing the hot water temperatures and brewing times improved the antioxidant properties for B. acutangular leaf tea. The hot-air dried B. acutangular leaf tea brewed with hot water at various temperatures contained higher levels of total phenolic compounds, total flavonoid, 2,2–Diphenyl–1–picrylhydrazyl (DPPH)-radical inhibition, 2,2’-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)(ABTS•+)-radical inhibition, and ferric reducing antioxidant power (FRAP) values compared to roasted B. acutangular leaf tea as brewed at lower temperatures and shorter brewing times (P≤0.05). Overall, B. acutangular leaf tea brewed with hot water at 90ºC for 10 min had the highest amounts of total phenolic compounds, total flavonoids, and the highest antioxidant effects.

Effects of Chlorine Dioxide and Sodium Hypochlorite in Culture Medium on Micropropagation of Pineapple (Ananas comosus) cv. Phulae

Tue, 25 Jun 2024 00:00:00 +0700

Plant tissue culture is widely used for pineapple propagation due to its ability to produce many plantlets but the cost of media sterilization through autoclaving is expensive. Medium supplemented with disinfectants can achieve sterility and cost reduction. However, these disinfectants could affect shoot multiplication and root induction of pineapple grown under aseptic conditions. Therefore, the objective of this study was to investigate the effect of various concentrations of sodium hypochlorite (NaOCl) and chlorine dioxide (ClO2) on shoot and root induction of pineapple cv. Phulae. In vitro shoots were cultured for 6 weeks on MS medium supplemented with 1 mg/L benzyladenine (BA) for shoot induction and on MS medium supplemented with 2 mg/L 1-naphthaleneacetic acid (NAA) for root induction. NaOCl at concentrations of 0.5, 1 and 2 mL/L and ClO2 at concentrations of 50, 75 and 100 mg/L were added to the medium for sterilization, compared to autoclaving (control). The experiments were arranged in a completely randomized design with 7 treatments and 4 replications. The results indicated that a 100% sterilized medium was obtained by adding NaOCl and ClO2. Furthermore, the application of 1-2 mL/L NaOCl and 50-100 mg/L ClO2 did not affect shoot and root induction. The number of shoots ranged from 3.81±0.53 to 5.16±0.33, the number of roots varied from 19.88±0.96 to 21.41±1.33, and root length ranged from 1.29±0.11 to 1.75±0.37 cm. After transplanting the plantlets, a 100% survival rate was achieved.

The Ability of Seedling Growth and Development of Pigeon Pea Selected Lines

Tue, 25 Jun 2024 00:00:00 +0700

Pigeon pea is an alternative protein plants that grows in tropical and subtropical humid regions, and is well-adapted to resist drought and climate change. Pigeon pea contains 18.8-24% protein and includes amino acids that contribute to balanced and beneficial health. Selecting pigeon pea lines that are effective in germination and the seedling growth stage is an important starting point for improving growth, adaptation and yield. This experiment aimed to assess the seed germination and seedling growth stages of selected pigeon pea lines. A total of 30 lines were chosen from the T9 mixed pigeon pea population to identify strains with early growth capacity before evaluating their growth and yield potential under growing conditions. The results showed that the selected pigeon pea line exhibited high variability in plant height, epicotyl length, hypocotyl length, and root length at 10 days after seeding. Additionally, variability in the selected pigeon pea lines at 30 days after seeding indicated statistically significant differences in plant height, epicotyl length, leaf length, leaf width, number of roots, fresh weight, and dry weight. The correlation coefficient of seedling growth at 30 days after seeding showed that plant height was highly positively correlated with epicotyl length (0.77). Lines P80-1-1, P38-6-1, P04-1-1, and P29-1-1 were identified as promising for further assessment of growth and yield potential in breeding programs.