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In this study, beryllium oxide nanoparticles (BeO NPs) were synthesized by polymer-gel method with schlenk line. The products were then assessed using FESEM, TGA/DSC, XRD and BET analyses. The quality of two nanooxides, that were calcined at 700 and 800 °C, was studied and compared with bulk BeO particles. The results showed that nanoparticles calcined at 800 °C were more uniform and had ellipsoidal morphology with a particle size of ∼35 nm. Investigation thermoluminescence (TL) characteristics of BeO NPs showed that with the decreasing exposed dose/increasing the BeO particle size, TL peaks were observed at higher temperatures. The intensities of glow curves increase linearly with the increasing absorbed dose in the range of 0.001 mGy–1000 Gy. Various other studies including response fading, minimum temperature and minimum time for annealing, and response changes in repeatability cycles of dosimeter also approved the ability of the prepared BeO NPs for use in gamma radiation dosimetry.

The adsorption effects of small molecules (H2O, CO, NH3, NO2) and large molecules (Tetracyanoquinodimethane (TCNQ) and Tetrafluoro-tetracyanoquinodimethane (F4TCNQ)) on electronic and magnetic properties of two triangular graphene antidot lattices (GALs), [10, 3, 6]RT A and [10, 5]ET A, are investigated by means of first-principles calculations. We find that CO, NO2, TCNQ, and F4TCNQ molecules are chemisorbed by both antidots, whereas NH3 is physisorbed (chemisorbed) by [10, 5]ET A ([10, 3, 6]RT A) structure. H2O, CO, NH3 molecules reveal no significant effect on electronic and magnetic properties of these antidot structures. The adsorbed NO2 molecules affect the energy gap of GALs by changing their electronic structure from semiconducting to half-metal nature. This suggests that both GALs can act as efficient NO2 sensors. The adsorption of TCNQ and F4TCNQ molecules on GALs induces flat bands in the vicinity of the Fermi energy and also turn the electronic structure of antidot lattices to half-metallicity. Among the small and large molecules, NO2 molecules induce the most total magnetic moment, paving the way to make magnetic GAL-based devices.

In this study, simulation of ab initio molecular dynamics with phonon spectral analysis was performed with the aim of understanding the two-dimensional thermal conductivity in graphene. Using the atomic velocities obtained from the simulation of ab initio molecular dynamics, and the analysis of spectral energy density, we calculated the lifetime of phonons in each mode. The calculations show that acoustical phonons ZA, LA and TA phonons have larger lifetimes and mean free path so they have more contribution in thermal conductivity. Among optical phonons, ZO-mode phonons, i.e. vibrations perpendicular to the graphene layer, have a longer lifetime than LO, TO models, but due to the low group velocity, their role in thermal vesting is negligible.

Fission fragment angular distribution (FFAD) data would help obtain new insights into both the fission process and the mechanism of the projectile’s interaction with the nucleus. Recently, a structure has been reported in neutron-induced FFAD of even-even actinide nuclei near threshold. Statistical modelling is used in this article to analyse FFAD from neutron-induced fission of 238U and 232Th. The statistical variance K02 is obtained by fitting the measured fragment anisotropies with a theoretical model. Accurate analysis is performed to deduce the variance K02 of the K-distribution of the levels in the transition nucleus at neutron energies from threshold to 50 MeV. We show the method by which quantitative values of K02 can be obtained. The results not only present high-resolution data in these even-even nuclei but also show that for the 238U(n,f) reaction, the strength for the K-transition states comes mainly from the higher angular momenta, in agreement with the Nilsson model orbitals. We also study the periodic structure of anisotropy related to the set of (n,f) reactions in comparison with the related cross section performed with the TALYS code. The comparison of the variance with the cross section clearly illustrates the strong correlation between the value of the variance and the opening of a fission chance. We show that whenever the probability of reaction in a new channel and cross section increases, K02 decreases versus the incident neutron energy, so the minimum of K02 can show the maximum probability of the (n,f)xn reaction.