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• Pub. Date : 2025
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This work investigates the possibility of getting rid of the accumulated plutonium around the world by mixing it with fertile materials and using it as a nuclear fuel for CANDU-6. Using plutonium isotopes with thorium as a nuclear fuel for CANDU-6 is a means of preventing the production of other Pu isotopes. MCNPX has been used to design a three dimensional model of the CANDU-6 bundle. Three fuel types including (238U, rgPu)O2, (232Th, rgPu)O2 and (232Th, wgPu)O2 have been examined as nuclear fuel in the designed model and their results were compared with UO2 as a standard fuel. The fuel burnup parameters such as kinf, fissile inventory ratio, plutonium concentration and minor actinides concentration have been analyzed for the suggested fuels. Some of the most related safety parameters such as effective delayed neutrons (βeff), moderator temperature coefficient, coolant temperature coefficient and Doppler constant have been studied. The excess thermal neutrons in the CANDU-6 maximized the benefit of using plutonium-based fuels, where a significant amount of plutonium has been burned during the fuel cycle. From the neutronic and safety point of view, thorium fuel mixed with reactor grade plutonium has proven to be the most promising candidate among the investigated fuels.

• Book : 57(1)
• Pub. Date : 2025
• Page : pp.1-9
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AbstractThe Juno Waves instrument can be used to accurately determine the electron density inside Io's orbit, the inner Io torus. These observations have revealed a local peak in the electron density just inside M = 5 and at centrifugal latitudes above about 10 that is likely the ’cold torus' as identified in Earth‐based observations of emissions. This peak or “finger” is separated from the more dense Io torus by a local minimum or ’trough’ at M 5. The electron densities are inferred by identifying characteristic frequencies of the plasma such as the low‐frequency cutoff of Z‐mode radiation at and the low‐frequency cutoff of ordinary mode radiation at that depend on the electron density. The “finger” density ranges from about 0.2 to 65 and decreases with increasing centrifugal latitude. The “trough” densities range from 0.05 to 10 . This pattern of a density “trough” followed by the “finger” closer to Jupiter is found on repeated passes through the inner Io torus over a range of centrifugal latitudes. Using a simple model for the electron densities measured above about 10 centrifugal latitude, we've estimated the scale height of the “finger” densities as about 1.17 with respect to the centrifugal equator, which is somewhat surprising given the expected cold temperature of the cold torus. The larger scale height suggests a population of light ions, such as protons, is elevated off the centrifugal equator. This is confirmed by a multi‐species diffusive equilibrium model.

• Book : 130(1)
• Pub. Date : 2025
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The majority of studies on laser-driven proton–boron nuclear reaction is based on the measurement of α-particles with solid-state nuclear tracks detector (Cr39). However, Cr39's interpretation is difficult due to the presence of several other accelerated particles which can bias the analysis. Furthermore, in some laser irradiation geometries, cross-checking measurements are almost impossible. In this case, numerical simulations can play a very important role in supporting the experimental analysis. In our work, we exploited different laser irradiation schemes (pitcher–catcher and direct irradiation) during the same experimental campaign, and we performed numerical analysis, allowing to obtain conclusive results on laser-driven proton–boron reactions. A direct comparison of the two laser irradiation schemes, using the same laser parameters is presented.

• Book : 32(1)
• Pub. Date : 2025
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Single crystals of potassium boro oxalate (KBO) and D-malic acid doped KBO (DMA-KBO) were grown by the slow evaporation method at room temperature. The crystal structure has been confirmed by the single-crystal X-ray diffraction method. The understudied material's functional groups have been confirmed by Fourier Transform Infrared spectroscopy (FT-IR). Their optical parameters have been evaluated using UV-visible (UV-Vis) spectroscopy. UV-Vis spectroscopy revealed higher transmittance in the visible region, with band gap energies reported at 5.35 eV for pure KBO crystals and 5.65 eV for those doped with malic acid. Scanning electron microscopy (SEM) analysis explores the structural morphology of the grown crystal. Energy dispersive X-ray spectrometry (EDS) has been employed to validate the effective incorporation of malic acid. Thermogravimetric and differential thermal analysis (TGA/DTA) revealed that the doped crystals exhibited thermal superiority over the pure KBO. Laser damage analysis showed that doping enhanced the crystals' resistance to laser radiation.

• Book : 17(1)
• Pub. Date : 2025
• Page : pp.165-176
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Millerettidae are a group of superficially lizard-like Permian stem reptiles originally hypothesized as relevant to the ancestry of the reptile crown group, and particularly to lepidosaurs and archosaurs. Since the advent of cladistics, millerettids have typically been considered to be more distant relatives of crown reptiles as the earliest-diverging parareptiles and therefore outside of ‘Eureptilia’. Despite this cladistic consensus, some conspicuous features of millerettid anatomy invite reconsideration of their relationships. We provide a detailed description of the late Permian millerettid Milleropsis pricei using synchrotron X-ray phase-contrast micro-computed tomography focusing on the cranial anatomy of three individuals known from a burrow aggregation. Our data reveal a suite of neuroanatomical features Milleropsis shares with neodiapsids that are absent both in other ‘parareptiles’ and in early diverging groups of ‘eureptiles’. Traits shared between Milleropsis and neodiapsids include: the presence of a tympanic emargination on the quadrate, quadratojugal and squamosal, the loss of epipterygoid contribution to the basicranial articulation suggesting a more kinetic palatoquadrate, the absence of a sphenethmoid and the pathway of the abducens nerve through the braincase. Our findings suggest that the early reptile neurocranium, a region poorly sampled in phylogenetic analyses due to relative visual inaccessibility and poor preservation, has the potential to inform the phylogenetic relationships of early reptiles.

• Book : 12(1)
• Pub. Date : 2025
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• Pub. Date : 2025
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