Journal of Science and Technology Phetchabun Rajabhat University

Preparation of activated carbon from agricultural waste hemp stalks using pyrolysis and microwave activation processes for the removal of methyl red dye

2025-07-21T15:04:44+07:00

Activated carbon was prepared from agricultural waste derived from hemp stalks through a pyrolysis process using a traditional charcoal kiln. The resulting charcoal was subsequently activated using microwave irradiation. The study identified the optimal activation condition as microwave power of 800 Watt for a duration of 3 minutes. The activated carbon exhibited a highly porous microstructure with numerous micron-sized pores. Characterization by SEM-EDS and FTIR techniques revealed a significant increase in carbon content in the activated carbon compared to raw hemp stalks and unactivated biochar, with carbon content exceeding 92%. The adsorption performance of the activated carbon was investigated using a synthetic solution of methyl red (MR) dye at an initial concentration of 300 mg L^-1 (100 mL volume). Adsorption was conducted under conditions of pH 3 at 30 °C, with 0.100 g of adsorbent, and agitation for 120 minutes. The activated carbon exhibited an MR removal efficiency of over 85%, with a maximum adsorption capacity (qₘ) of 270.27 mg g^-1. The adsorption behavior was consistent with both the Langmuir and Freundlich isotherm models. Thermodynamic parameters demonstrated DG < 0 and DH⁰ of -31.0412 kJ mol^-1K^-1, indicating that the adsorption process was exothermic, multilayered, and characterized by a high density of adsorbed molecules on the surface of the adsorbent. Therefore, the microwave-activated carbon derived from hemp stalk waste exhibits excellent adsorption properties and can be effectively utilized for the removal of MR dye from aqueous solutions.

On the Diophantine equation 3^x-2.5^y=z^2

2025-07-24T11:19:18+07:00

In 2022, Gope and Masud proved that the Diophantine equation has no non-negative integer solution. After studying, we found that the Diophantine equation has a non-negative integer solution. Thus, in this article, we show that the Diophantine equation has exactly two non-negative integer solutions , which are and , by using basic knowledge of number theory. Moreover, the results can also be extended to other related forms of Diophantine equations, such as multiples of X, Y+1, multiples of Z²ⁿ and .

Beef Cattle Production Efficiency Improvement Through Different Breeding Program in Khao Kor and Bueng Sam Phan District, Phetchabun Province

2025-07-30T12:05:07+07:00

This study aimed to improve beef cattle production by implementing a seasonal breeding program that utilizes estrus synchronization with different hormones to enhance the conception rate and artificial insemination (AI) in Khao Kho and Bueng Sam Phan Districts. A total of 90 beef cattle were randomly selected from the two districts (45 from each district). These cattle were assigned to three treatments with 15 cattle per group. All selected cattle underwent fertility examinations and had a body condition score (BCS) of at least 2.50. The experimental design was a randomized complete block design (RCBD) with two districts as blocks. The experimental groups included group 1: natural estrus (control), group 2: induced estrus by hormone and scheduled the duration for artificial insemination (GnRH + PG) and group 3: induced estrus by hormone plus CIDR^® and determine of the duration of artificial insemination (GnRH + PG + CIDR^®). The results indicated that the treatments did not significantly affect reproductive efficiency, first-service conception, and the artificial insemination index in both districts (P> 0.05). However, the estrus synchronization programs did lead to a slightly higher first-service conception rate. Further research is recommended to develop estrus synchronization programs that can benefit beef cattle farmers.

Geographic Information System for Managing Natural and Historical Tourism in Sara Buri Province

2025-09-04T11:05:40+07:00

This research aimed to (1) create a database of natural and historical tourist attractions and (2) determine optimal travel routes in Saraburi Province. Location data were collected using the Global Positioning System (GPS), and the database was developed with ArcGIS Version 10.5. The Network Analysis tool was employed to identify optimal the travel routes to the selected attractions. The resulting database consists of spatial data showing geographic locations and attribute data providing descriptions and images of each site. A total of five travel routes were identified, comprising two natural and three historical routes: Natural Tourist Routes: No.1 “Embrace Nature” – 82 kilometers, 8 hours 25 minutes No.2 “Trekking, Camping, and Stargazing” – 65 kilometers, 43 minutes Historical Tourist Routes: 1) “Pay Respect, Make Merit, and Retrace History” – 65 kilometers, 5 hours 13 minutes 2) “Enjoy Souvenir Shopping in Sao Hai District” – 6.5 kilometers, 5 hours 4 minutes 3) “Visit Temples and Pay Respect to the Buddha’s Footprint” – 132 kilometers, 8 hours 18 minutes. This study emphasizes the effectiveness of Geographic Information System (GIS), particularly through Network Analysis, in supporting efficient travel planning and promoting sustainable tourism development in Sara Buri Province.

Numerical Analysis and Experimentation of an AC Voltage Regulator for Spot Welding Machine

2025-08-25T16:12:33+07:00

This study aimed to present the development of a chain welding machine equipped with voltage level control and to analyze the results obtained from measuring the input voltage of the transformer in comparison to numerical mathematical analysis.The experiment was conducted by regulating the welding current using a microcontroller, which generates trigger signals for the Silicon-Controlled Rectifier (SCR) in a single-phase full-wave AC-AC converter circuit. The experimental results were compared to numerical analysis, and the study found that it is feasible to control the welding current to suit the specific type of chain being used. The AC voltage adjustment unit connected to the chain welding machine was utilized to adjust the voltage for welding chains of various sizes. The results obtained from mathematical analysis were found to be consistent with the experimental results in adjusting the voltage, with a maximum discrepancy of 6.18% compared to numerical mathematical analysis.

Effects of Marigold Crude Extract Supplementation in Diets on Body and Caudal Fin Coloration Intensity in Siamese Fighting Fish (Betta splendens)

2025-08-30T23:05:36+07:00

Siamese fighting fish is an economically important ornamental fish popular among aquarists for its variety of patterns and colors. The shade and intensity of its color are correlated with the pigment intake from the diet. A commonly used natural source in fish feed supplementation is marigold flower, which contains high levels of lutein in the carotenoid group. However, information on the optimal concentration of marigold extract for maximizing color enhancement in this species remains limited. This study, therefore, aimed to investigate the effect of supplementing marigold extract, prepared with 95% ethanol, in the diet at levels of 0%, 3%, 5%, and 7% on improving the color intensity of the body and caudal fin of the fish over a period of 5 weeks. Color assessment was performed using the RGB system from photographs. The results showed that marigold extract supplementation significantly enhanced the color intensity of the body and caudal fin, with the 5% level (3.66 mg/ml estimated lutein content) yielding the best results for all color values (R, G, B) on both the body (average R-value increase of 55.05) and caudal fin (average R-value increase of 48.29) when compared to the control group (p < 0.001). This study confirms the potential of marigold extract to enhance the coloration of this ornamental fish, with the 5% level being the appropriate inclusion rate.

The Use of Clove and Galangal Medicinal Plant Extracts to Control Fungi from Rotten Peanut Pods, Nikhom Sang Ton Eng Subdistrict, Mueang District, Lopburi Province

2025-09-10T15:21:09+07:00

This research aimed to study the efficacy of essential oil extracts from medicinal plants, clove and galangal in inhibiting fungi causing peanut pod rot. The research was divided into three activities: 1) isolation and identification of fungi from rotten peanut pods, 2) testing the efficacy of extracts in inhibiting fungi, and 3) field trial evaluation. Results showed that 10 isolates were obtained, with dominant isolates No.1(1), No.3(2), and No.3(5) identified as Aspergillus spp.
Testing the efficacy of essential oil extracts from clove, galangal, and clove+galangal at concentrations of 10, 50, and 100 percent revealed that clove extract had the strongest inhibitory effect against fungi. At 50% concentration, it could inhibit fungi isolates No.1(1), No.3(2), and No.3(5) by 68.27±1.42%, 71.79±1.81%, and 71.15±1.23%, respectively. Field spraying tests with 50% (w/w) clove oil showed disease severity reduction comparable to carbendazim treatment. Technology transfer evaluation found that participants had the highest levels of knowledge/understanding, satisfaction, and practical application at 4.82±0.39, 4.78±0.46 and 4.86±0.39, respectively.
This research demonstrates the potential of medicinal plant extracts in controlling pathogenic fungi in peanuts and provides an alternative to reduce chemical usage.