Journal of Earth Science, Astronomy and Space

Assessment of Carbon Sequestration in the Ban Pong Salod Community Forest, Nong Kapu Subdistrict, Ban Lat District, Phetchaburi Province

Supada Khunnarong — 2025-12-26

This study aimed to evaluate the carbon sequestration potential of the Ban Pong Salod Community Forest, located in Nong Kapu Subdistrict, Ban Lat District, Phetchaburi Province, Thailand. Field surveys and data analyses were conducted in a 40 × 40 m sample plot (equivalent to 1 rai) within a total community forest area of 100 rai. The plot was subdivided into sixteen 10 × 10 m subplots. A total of 27 tree species were identified, with Sampantaea amentiflora (Airy Shaw) (locally known as Sam Phan Ta) being the most abundant, showing a density of 125 trees per rai. The species with the highest carbon sequestration, carbon dioxide uptake, and oxygen release was Afzelia xylocarpa (Makha Mong), which stored 0.47352 ton of carbon per tree, absorbed 1.73624 ton of CO₂ per tree, and released 1.26272 ton of oxygen per tree. The total carbon sequestration across all 16 subplots was 15.73877 ton/rai, with total CO₂uptake and oxygen release calculated at 57.70884 ton/rai and 41.97006 ton/rai, respectively. Based on the average 2024 TVER carbon trading price for forestry projects of 509.34 THB/ton, the estimated carbon credit (tCO₂e) value was 29,393.42 THB/rai.

Orbital Period Change of the Binary System V700 Cyg

Supat Sairattanain — 2025-12-26

This research aims to investigate the orbital period change of the contact binary system V700 Cyg, classified as a W Ursae Majoris (W UMa)-type binary. Observations were carried out using a 0.7-meter reflecting telescope equipped with a CCD sensor and B and V photometric filters at the Regional Observatory for the Public, Songkhla on August 7, 2021. The photometric data obtained were used to construct light curves and determine the times of minimum light, which were then used to generate an O–C diagram. The analysis reveals that the orbital period of V700 Cyg is gradually decreasing, with the change of 9.98 × 10^-4 seconds per year. This indicates that the two stellar components are slowly spiraling closer to each other over time. That explained the by the Angular Momentum Loss (AML) evolution theory.

Evaluation of In Silico Screening Techniques for Predicting and Comparing Bioactivities of Compounds from Dragon’s Blood Tea

Pattharavadee Siriamnuaylap — 2025-12-26

This study aimed to evaluate the potential of in silico screening techniques for predicting the bioactivities of compounds found in Peristrophe roxburghiana (Dragon’s Blood Tea) and to compare the computational predictions with preliminary experimental data to assess their consistency. Nineteen organic compounds previously reported in published studies were selected and modeled into three-dimensional (3D) structures. These structures were analyzed using freely available online platforms, including the SEA server, PharmMapper server, and PASS online, to predict their possible biological activities. The in silico results were then compared with in vitro findings obtained from the determination of total phenolic content (TPC) of extracts from Dragon’s Blood Tea leaves and fresh leaves of P. roxburghiana. The results revealed that anthocyanidin glycosides from the methanolic extract exhibited potential antioxidant, anti-inflammatory, and anticancer activities, while alkaloid compounds from the aqueous extract showed antineoplastic and anti-inflammatory potentials. These findings were consistent with the high TPC values observed in the aqueous extracts. The outcomes suggest that in silico screening can effectively identify bioactive compounds and serve as a supportive tool for natural product research. Moreover, the freely accessible databases and software used in this study provide a cost-effective and practical approach for researchers investigating bioactivity prediction of natural compounds.

A Study of the Astronomical Alignment of Prang Ku Monuments in Chaiyaphum Province with Solar Movements

Kiadtichai Tavilab — 2025-12-26

This research aims (1) to study the orientation of Prang Ku Monuments in Chaiyaphum Province using digital mapping software, and (2) to determine the dates when the rising and setting of the sun aligns with the doors of the Prang Ku by calculating the declination of the sun. The azimuth angles of the Prang Ku monuments were measured in relation to longitude using the digital mapping software. These azimuth angles and the geographic latitudes of the Prang Ku locations, were used to calculate the sun’s declination in order to identify the dates when the sunrise aligns with the doorways of the Monuments. The study revealed that only four Prang Ku monuments in Chaiyaphum Province exist in a relatively intact state. These structures are oriented along an east-west axis and face slightly northeast, corresponding with the sunrise that aligns with the doorway in April and September, during which the sun enters the zodiac sign of Aries according to the Maha Sakaraj calendar, marking the solar New Year or Thaloeng Sok, which adds another year to the calendar cycle influenced by Indian culture that got adopted by the Khmer Empire. These structures may have been built as ancient instruments for dividing time and seasons, functioned as an ancient calendar. Studying the orientation of the Prang Ku monuments reveals the wisdom of ancient builders in designing architecture that utilizes the position of the sun to determine optimum orientation, aligning functional space use with astronomical events.