The Khorat Plateau is Thailand's largest uranium-bearing region and is well known for its Mesozoic sandstone-hosted uranium deposits and abundant dinosaur fossil localities. Recent studies have identified naturally radioactive fossils formed through the incorporation of naturally occurring radionuclides during fossilization and post-burial diagenesis. However, the implications of this natural radioactivity for occupational exposure during fossil excavation and handling remain poorly understood. This study presents the first comprehensive radiological assessment of Thailand's dinosaur fossil excavation sites by combining long-term field monitoring with laboratory characterization of naturally occurring radioactive materials (NORM).Field investigations were carried out at the indoor Phu Wiang (Khon Kaen Province) and outdoor Phu Noi (Kalasin Province) excavation sites. Ambient gamma dose rates measured using optically stimulated luminescence dosimeters ranged from 0.052 to 0.171 μSv·h−1, while radon concentrations measured using RADUET CR-39 detectors ranged from 3.158 to 74.012 Bq·m−3, with generally higher values during winter. One-way ANOVA showed significant seasonal variation in radon concentrations at the Phu Noi site (p-value < 0.001), whereas no significant seasonal difference was found at the Phu Wiang site (p-value = 0.129). High-purity germanium gamma-ray spectrometry of 33 soil samples yielded mean activity concentrations of 41.14 ± 11.55 Bq·kg−1 for 226Ra, 54.80 ± 14.82 Bq·kg−1 for 232Th, and 965.89 ± 313.81 Bq·kg−1 for 40K. Gamma dose rates measured from 37 fossil specimens differed significantly between the two excavation sites (Welch's t-test, p-value < 0.001), suggesting localized radionuclide enrichment during fossilization.Although some measured values exceeded worldwide average background levels, the estimated occupational radiation doses remained below internationally accepted protection limits. These findings support routine radiation monitoring, adequate ventilation, and appropriate work planning, particularly in enclosed environments. This study provides the first scientific basis for radiation protection and safety management at Thailand's dinosaur fossil excavation sites.
In English-Medium-Instruction (EMI) classes, the co-construction of intersubjective understanding among multilingual and multicultural students for subject-matter acquisition is complex, involving an interplay of multimodal resources-at-talk. This dynamic process is reflected in students' interactional competence (IC), foregrounded as a crucial component of their content learning. Despite its importance, scant attention has been paid to the constitutive components of IC. To address this gap, the current study aimed to develop and validate a comprehensive instrument to assess EMI students' IC in their learning situations. A five-point Likert-scale questionnaire was developed and validated prior to a pilot study involving 104 EMI students. The main study included 504 EMI students, and exploratory and confirmatory factor analyses were conducted. The results revealed a seven-factor model of IC comprising 27 valid items: non-linguistic resources, social action, interactional mechanisms, content knowledge, psychological aspects, linguistic knowledge, and pragmatic knowledge. The explained variance also reflects the nature of EMI students' interaction within contemporary educational complexities, particularly a shift from language accuracy towards the intelligibility. The findings offer implications for EMI teachers, classroom activity designers, and researchers by elucidating the constituent components of IC that should be leveraged to support EMI students' content learning and future real-world communication.
Post-recycling plastic waste contamination in freshwater ecosystems represents an escalating environmental threat, while algal blooms continue to generate vast quantities of underutilized biomass. Addressing both challenges, this study investigated the co-hydrothermal liquefaction of Chlorella pyrenoidosa with representative post-recycling plastic wastes polypropylene, polyethylene terephthalate, and Nylon-6 as a dual-resource valorization strategy. Experiments were conducted in a 1000 mL high-pressure batch reactor at 350 degrees C for 30 min, with varying biomass-to-plastic feed ratios. Systematic product characterization, including functional group, elemental analysis, Van Krevelen diagrams, and heating value assessment, was employed to elucidate synergistic effects and evaluate product quality. Results revealed that co-processing with polyethylene terephthalate achieved the highest biocrude yield of 71.5%, with an enhanced higher heating value of 35.7 MJ kg-1, surpassing the 62.4% yield from microalgae alone. Nylon-6 blends also improved oil yield to 69.6% while producing aqueous fractions enriched with epsilon-caprolactam, indicating the recovery of valuable nitrogenous monomers. In contrast, PP exhibited limited reactivity toward oil generation but produced carbon-rich biochar with a higher heating value up to 41.4 MJ kg-1, comparable to high-grade solid fuels. Mechanistic analyses confirmed that plastics acted as hydrogen donors, promoting deoxygenation, radical stabilization, and selective depolymerization, thereby improving both liquid and solid fuel fractions. By employing ecologically relevant freshwater feedstocks from Thailand, this work advances beyond prior studies dominated by marine biomass or synthetic surrogates, providing realistic insights into resource integration within polluted inland waters. The co-hydrothermal liquefaction process simultaneously mitigates eutrophication-driven algal blooms and persistent plastic pollution while generating fuels and functional carbon materials, directly contributing to a circular bioeconomy. The demonstrated synergy between biological and synthetic wastes highlights a scalable, catalyst-free route to energy-dense biofuels and multifunctional biochar. These outcomes align strongly with SDG which offer a pragmatic framework for waste-to-energy transition in freshwater-dependent regions.
Simulium asakoae is a widespread species of black fly in Southeast Asia and a potential vector of parasites of medical and veterinary importance. Despite its broad distribution and diverse habitats, population genetic information remains limited. We investigated the genetic diversity, population structure, and demographic history of S. asakoae in Laos and examined its genetic relationships with populations from other Southeast Asian countries, using mitochondrial cytochrome c oxidase subunit I (COI) sequences. A total of 369 COI sequences (241 generated in the present study and 128 retrieved from GenBank) were analyzed. Of these, 284 sequences (241 from this study and 43 from GenBank) originated from nine locations across five provinces in Laos. Among the Laotian specimens, 51 haplotypes were identified, showing high haplotype diversity (Hd = 0.9063) and moderate nucleotide diversity (π = 0.0080). Intraspecific genetic divergence among Lao populations ranged from 0 to 2.49
Sustainable irrigation planning under increasing water scarcity requires efficient allocation of limited water resources while simultaneously considering land suitability and agricultural productivity. In this study, we aim to identify optimal cropping patterns for sustainable irrigation management using an optimization-based decision-support framework applied to the Nam Mang 3 Irrigation Project in Lao PDR, based on data from 2022. Focusing on the dry season (November-April), we evaluated six major crops-rice, beans, maize, tomato, cucumber, and watermelon-under six irrigation scenarios to assess the impacts of land suitability and water availability. The analysis incorporated a water availability range from 17.70 to 18.10 mm3 to evaluate system robustness. Linear Programming (LP), the Genetic Algorithm (GA), and the African Vultures Optimization Algorithm (AVOA) were employed to determine optimal crop allocation. The proposed framework explicitly incorporates varied soil types and land-use constraints, providing a more realistic representation than conventional homogeneous assumptions. The results indicate that AVOA outperformed other models in terms of stability. Under the evaluated scenarios, the optimal cultivated area ranged from 3192 to 3200 ha, with total profits fluctuating between 34,125,930 and 34,314,900 US$. These findings demonstrate that integrating soil variability and sensitivity-based optimization significantly enhances irrigation planning, providing a practical, robust decision-support tool for planners to design adaptive and sustainable cropping strategies in water-scarce regions.
