The study of the movement of an electron in a semiconductor quantum well with BenDaniel-Duke boundary conditions and of the propagation of a transversal magnetic wave in the active region of a semiconductor laser generate equivalent Sturm-Liouville problems.

The control of Macroscopic quantum self-trapping (MQST) in two coupled Bose-Einstein condensates with two- and three-body interactions is investigated. The terms representing the modulated two- and three-body interactions can be merged into one acting as the controlling parameter of the system. This facilitates the control of the system through the two- and three-body interactions. For the symmetric case adjusting the total modulating intensity of the two- and three-body interactions can effectively weaken and even eliminate the MQST. But when the total modulating intensity reaches a critical value the MQST will re-emerge in the same well and not shift to the other even for a large total modulating intensity. In some regions of the total modulating intensity the system is always in MQST states with nonzero constant population imbalances after transient processes, denoting the shutdown of atom tunnelling. For the asymmetric case adjusting the total modulating intensity can lead to shift of MQST between the two wells and no MQST states with constant population imbalance are found. In both symmetric and asymmetric systems increasing the modulating frequency can result in MQST states with nonzero constant population imbalances.

In this paper, we examine time-fractional Boussinesq-like B(m,n) equations that model some real-life systems, where the Caputo sense of fractional derivative has been used. The examined equations are characterized by a set of initial and boundary conditions. We will apply the homotopy perturbation method for analytical treatment of these equations. A comparison between our solutions and other existing solution in the literature, shows accuracy of the employed analysis. Proper graphs are used to illustrate the obtained results.

We present the experimental results on a hydrogen atom migration preceding fragmentation of the furan molecules induced by the H₃⁺ and C⁺ impact. The excited OH(A²Σ⁺) radical has been detected among the furan decomposition products using collision-induced emission spectroscopy. However, the OH moiety is absent in the furan ring skeleton, so detecting the OH(A²Σ⁺→X²Π) luminescence indicates the intramolecular H atom relocation prior to cation-induced fragmentation. Guided by the most recent theoretical calculations, the dissociation mechanism that governs the OH(A²Σ⁺) formation observed in this work is elucidated.

The pulsed-plasma treatment (PPT) was applied for surface modification of the biomedical alloys (316L, Ti-6Al-4V, Co-28Cr-6Mo) fabricated by the “Laser Based-Powder Bed Fusion” process. The subsurface modified layer was formed through the melting to the depth of about 20 μm. Plasma modification led to surface densification of the alloys with the pores eliminating. PPT decreased the hardness and wear resistance in simulated body fluid (SBF) of 316L steel while it did not have a significant effect on SBF-sliding wear behaviour of Ti-based and Co-based alloy.

The model of mechanically strained CdSe quantum dot with a multilayer shell is constructed. The proposed model takes into account the deformation that occurs due to the mismatch between the lattice parameters of the core and the shell and between the individual layers of the shell, the deformation due to surface curvature (Laplace pressure) and the external hydrostatic pressure. The dimensional dependence of elastic constants of the quantum dot materials is also taken into account. The calculations of deformation of the CdSe-core / ZnS-shell, CdSe-core / ZnS/CdS-shell, CdSe-core / ZnS/CdS/ZnS-shell quantum dots at different geometric sizes of the core and individual layers of the shell were performed. The regularities of change in the deformation of quantum dot materials under the action of external pressure are investigated. The obtained results are important in the research of optical and electrical properties of quantum dots with a multilayer shell, because the deformation significantly modifies the band structure of quantum dots.

In-air PIXE at the NIPNE Tandetron using 3 MeV protons and a SDD detector has been applied for qualitative elemental analysis of dental composites. Up to 15 elements including traces have been detected in these dental biomaterials. The performances of in-air PIXE have been compared with those of in-vacuo PIXE, as well as those of XRF and SEM/EDS form other laboratories. Spectra of in-air PIXE presented better resolution than in-vacuo PIXE, and both techniques achieved better analytical performances than the other X-ray spectrometry methods. The elemental compositions of two new “bulk” dental composites have been compared to those of the corresponding “classical” materials of an older generation. Compositional differences were evidenced, pointing to different composites’ development strategies of the producers. In addition to the experimental study, a formal treatment has been proposed, aiming to reduce the qualitative analysis data to a few quantitative parameters. Thus in-air PIXE analysis of dental composites with the present setup has an important potential for various qualitative and semiquantitative applications. However, upgrading the setup with a system for collected charge measurement is recommended for quantitative analysis.

Values of electron backscattering factors (EBFs) for 3 MeV and 7 MeV electron beams generated by the NOVAC7 IOERT accelerator have been calculated, by the Monte Carlo method, for 2 mm Pb shields as well as for (2 mm Al + 2 mm Pb) shields inserted at different depths in a water phantom. Our results confirm the efficiency of Al/Pb shields in the protection of healthy tissues beyond the target volume and, at the same time, in the mitigation of dose enhancement effects at shield interface due to electron backscattering.

Geological investigations in Abu Murrat, Egypt, reveal that iron oxide mineralizations of the study area are essentially associated with gabbroic rocks that are bearing iron oxides minerals as lenses or bands in the bottom of the layers, fact related to magma enrichment of iron oxides. The geochemical investigations suggest that Abu Murrat Fe-Ti oxide bearing gabbro falls in volcanic arc field and has tholeiitic affinity, with a mainly ferrobasaltic magma composition. The concentrations of major oxides and trace elements were determined by X-ray fluorescence (XRF) and the rare earth elements (REEs) by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Although the compatible elements recorded high values in both host and Fe-Ti oxide deposits, the geochemical behavior of elements can be used as an evidence of magma mixing. In contrast, the investigation shows an enrichment of Large Ion Lithophile Elements (LILEs) and depletion of High Field Strength Elements (HFSEs) both in gabbroic rocks and Fe-Ti oxide deposits as a result of the subduction zone between continental and oceanic plates. Furthermore, REEs are the most depleted elements among the analyzed elements. Nonetheless, the Light Rare Earth Elements (LREEs) are highly enriched in these rocks compared with Heavy Rare Earth Elements (HREEs). This characteristic provides an index to magma contamination by addition of some LILEs and LREEs from the subduction slap or its fluids.

This work presents the changes of the aerosol properties during COVID-19 lockdown. Data was collected during the intensive observation campaign organized in May 2020 by the European Aerosol Research Lidar Network (EARLINET). The results obtained for Magurele region emphasize that the reduced traffic and industrial activity determined a decrease of small aerosol particles.

Fiber optic dosimeters are attractive devices and intensively researched in several areas related to radiation due to their properties and characteristics. The present paper continues our previous research on the behavior of optical fibers under electron irradiation in order to the development of optical fiber dosimeters. Three commercially available single-mode optical fibers types, estimating the performance and potential of these for the possible use in radiation monitoring applications has been use. As in the others the recent studies, our results show that the attenuation response of single mode optical fibers depends linearly on a certain range of the radiation dose and exponential for each irradiation step. The optical fiber surface defects due to irradiation were investigated by Scanning Electron Microscopy (SEM).

NiTi cylindrical materials were obtained by spark plasma sintering at 850°C or 900°C from high purity Ni and Ti powders. These mixtures were previously processed by mechanical alloying for 8 and 15 hours. In order to increase the alloy homogeneity, the NiTi materials were subjected to post aging treatment in protective atmosphere at constant temperature 400°C and cooling in water with ice. All samples were characterized by optical microscopy, differential calorimetry (DSC), X-ray measurements (XRD) and micro/nanoindentation measurements. The results demonstrate that the NiTi materials obtained by this preparation route have good mechanical properties and can serve as a quantitative reference for the microstructure design of shape memory materials for various applications, such as the biomedical ones.