Journal of Physics and General Science

Growth Performance, Yield Components, and Consumer Preference of Eleven Muskmelon Varieties in Songkhla Province

Karistsapol Nooprom — 2025-12-30

The objective of this study was to evaluate the responses of eleven muskmelon varieties in terms of growth performance, yield components, and consumer preference. The experiment was conducted under greenhouse conditions in Songkhla Province, southern Thailand, using a completely randomized design (CRD) with three replications and twelve plants per replication. Results revealed significant differences (P ≤ 0.05) among the musk-melon varieties. Green Shizuoka, Orange Pearl and Takami exhibited superior growth performance, particularly in stem diameter and leaf area index (LAI), and reached harvest maturity earlier than the other varieties, with harvest dates occurring 1.56 to 2.44 days earlier. Orange Pear, Green Rocky and Orange Rocky produced higher yield components, including fruit length, width, and weight. Regarding fruit quality, Green Pearl and Alpha had the highest total soluble solids, with 15.77 ° Brix and 15.31 ° Brix, respectively. Consumer preference, evaluated using a nine-point hedonic scale, indicated that Green Rocky, Orange Rocky and Alpha received higher mean scores for taste (7.40–8.00), texture (7.30–8.00), and overall liking (7.45–8.17) than the other varieties. Therefore, Orange Pearl, Green Rocky, Orange Rocky and Alpha were identified as the most suitable varieties for comercial production in Songkhla Province and surrounding areas of southern Thailand.

Design and Fabrication of Cost-Effective Plaster Molds for Natural Rubber Foam

Darika Jaaoh — 2025-12-30

Due to the increasing demand for biodegradable cushioning materials, this study develops a low-cost plaster mold for forming natural latex foam and compares molds with edge thicknesses of 5 mm and 10 mm in terms of service life, physical properties, and thermal behavior. Results show that the 10-mm mold is markedly more durable, withstanding 14 cycles before failure, whereas the 5-mm mold endures only 6 cycles. Microstructural analysis indicates that foam produced from the thicker mold features smaller, more uniform cells with higher density, resulting in better compression resistance and recovery. Foam from the 10-mm mold shows an average density of 0.276 g/cm³ and a compression set of 6.43 %, compared with 0.243 g/cm³ and 7.60 % for the 5-mm mold. For thermal performance, the 10-mm mold exhibits higher thermal conductivity (0.6830 W/m·K) than the 5-mm mold (0.4674 W/m·K). The greater thickness slows water evaporation during setting, promoting tighter packing of calcium sulfate dihydrate crystals, improved solid-phase continuity, and reduced porosity, all of which enhance heat-transfer pathways. In contrast, the thinner mold tends to develop air voids from rapid moisture loss, reducing structural continuity and thermal conductivity. The increased thickness also produces a more uniform internal temperature distribution and lowers surface heat loss, allowing measured conductivity to better represent the material’s intrinsic properties.

Design and Development of a Low-Speed Horizontal Permanent-Magnet Synchronous Generator

Siriporn Testhong — 2025-12-30

This research aims to design, construct, and test a low-speed, horizontally mounted permanent-magnet synchro-nous generator. The prototype was fully fabricated from newly manufactured components and evaluated at operating speeds ranging from 100 to 500 rpm. The test results show that the generator can produce a maximum electrical power output of 1 kW, with the three-phase output voltage increasing proportionally with the rotational speed. Under practical test conditions, the generator delivered an electrical power of approximately 250 W. In addition, the voltage and current exhibited a phase angle of 120 electrical degrees, confirming proper three-phase operation. These findings indicate that the developed generator operates effectively and is well suited for low-speed applications.

Analysis of the Relationship between Climate Change and Extreme Rainfall Events Influencing Flooding in Songkhla Province

Phayao Yongsiriwith — 2025-12-30

This research aims to analyze the relationship between climate change factors and rainfall patterns influencing flooding in Songkhla Province. The study utilizes a 20-year dataset (2003–2022) of rainfall from the Southern Meteorological Center (East Coast), specifically during the monsoon months of October to December. The analysis identifies 8 El Niño years, 11 La Niña years, and 1 neutral year within the study period. Findings reveal that years with total rainfall exceeding the mean threshold of 1,500 mm predominantly coincided with La Niña events (10 out of 11 years). Furthermore, an investigation of extreme daily precipitation—defined as rainfall exceeding 200 mm, a primary driver of flooding—identified 11 occurrences, 10 of which were strictly associated with La Niña cycles. These results conclusively demonstrate that rainfall variability and flood risks in Songkhla are heavily driven by the La Niña phenomenon, reflecting the localized impacts of global climatic shifts.