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.
The introduced investigation demonstrates an extensive finite element analyzation in order to explore thermal transportation features of engine oil enriched with triadic hybrid Nano-size particles exposed to 3D inclined plate incorporated with non-Fourier thermal conduction combine with thermal radiation influence. The mathematical modeling is established by incorporating thermal relaxation impacts to attain definite thermal wave speed, which are pivotal in high temperature and also in nanoscale thermal systems. For the realistic description radiative thermal flux, non-linear thermal radiation is invoked exposed to high temperature gradients. The acquired coupled comprehensive partial differential equations specified by momentum as well as energy transport are modified into a weak variational structure and numerically solution is obtained by utilization of robust finite element approach. The impacts of key physical constraints, including Nano-scale particle volume fraction, radiation as well as also thermal relaxation constraint and inclination angle across temperature compartment and also thermal transportation rate is discussed in detail. Attained outcomes depicts that the inclusion of triadic hybrid Nano size particles considerably intensifies thermal efficiency in contrast to conventional fluids, whilst non-Fourier features moderate thermal propagation closed to the plate surface. The proffered examination highlights the collective role of Nanoscale synergy and also modified thermal conduction theory in enhancing thermal management particularly of lubricated mechanical systems.
Room-temperature Na-S batteries (RT-NSBs) hold great promise for high-energy-density storage, but their practical deployment remains hindered by polysulfide dissolution (i.e., shuttle effect), sluggish sulfur redox reactions (SRR), and limited ionic transport. Rational design of electrocatalysts with a strong adsorption affinity toward polysulfides and high catalytic activity is therefore essential to address these issues. In this work, we employ density functional theory (DFT) to investigate N-, O-, and dual (N, O)-doped MoS2 as potential electrocatalytic cathode hosts for RT-NSBs. Unlike most previous studies that solely assessed Na2Sn adsorption in the gas phase, we utilized an implicit solvent model to incorporate intrinsic electrolyte effects on polysulfide stability. We show that this approach yields lower Na2Sn binding energies on the cathode hosts as compared with the gas-phase approach due to solvent polarity and dielectric screening, indicating the importance of solvation in evaluating polysulfide dissolution. N-, O-, and (N, O)-doped MoS2 exhibit sufficiently strong Na2Sn adsorption to mitigate the shuttle effect. Nevertheless, their catalytic behaviors differ considerably. While N- and O-doped MoS2 (monodoped MoS2) provide limited SRR enhancement, (N, O)-doped MoS2 delivers significantly improved catalytic activity. This is attributed to the significant population of antibonding states in the N-Na and O-Na bonds formed at the interface of (N, O)-doped MoS2 and Na2Sn, inducing s- and p-band shifting after interacting with Na2Sn to catalytically activate the conversion of Na2Sn in the SRR. Kinetic analysis quantitatively shows that (N, O)-MoS2 markedly lowers the rate-determining barrier of the SRR from 0.93 eV in pristine MoS2 to 0.57 eV. These results identify (N, O)-doped MoS2 as a highly effective cathode host for RT-NSBs.
This paper presents a reliability-based design optimization (RBDO) specifically applied to the design of low-speed wind turbines (LS-WT). The research explores the impact of uncertainty on optimum blade design by using metaheuristic (MH), integrating blade element momentum (BEM) theory for aerodynamic analysis and finite element analysis (FEA) for structural evaluation. Uncertainties, including tip speed ratio and allowable stresses, are modeled as truncated normal distribution. The multi-objective optimization problem is minimized total mass while maximized power output and the reliability index. Constraints include buckling factor, displacement, and the probability of failure. The optimum latin hypercube sampling (OLHS) is utilized to quantify uncertainty, compute the probability of failure, and reliability index. The distribution of uncertainties was investigated to assess its influence on optimum results. Findings show that reducing uncertainty levels enhances Pareto fronts while maintaining reliability index.
Methoxyacetic acid (MAA) is a testicular toxin that targets spermatocytes and round spermatids by disrupting mitochondrial function, leading to cellular energy depletion. Male Sprague-Dawley rats were given single oral doses of MAA (150 or 650 mg/kg), resulting in no mortality but transient toxicity signs and modest body weight effects, especially at the higher dose. Histopathology revealed dose- and time-dependent testicular damage, with selective germ cell necrosis by 48 h and extensive germ cell loss, spermatic giant cells, and epididymal inflammation observed in high-dose animals by 168 h. Metabolic analysis using high resolution 1H NMR spectroscopy and OPLS-DA identified elevated urinary excretion of N-butyryl glycine, a marker of mitochondrial dysfunction and impaired β-oxidation. The persistence of N-butyryl glycine and altered energy metabolites up to 168 h indicates sustained mitochondrial stress and disruption of ATP-dependent processes essential for spermatogenesis. Moreover, the close structural similarity between MAA and butyrate raises the possibility that MAA interacts directly with enzymes involved in butyryl-CoA turnover during the terminal steps of β-oxidation in rodents.
