This study conducts a thorough numerical investigation employing the bvp4c technique to delve into the stagnation-point flow of a magnetohydrodynamic (MHD) Casson polymeric nanofluid around a wavy circular porous cylinder. It takes into account activation energy and thermal radiation, emphasizing the significant impact of thermal radiation on fluid flow, concentration and temperature profiles. The effects of thermal radiation within the energy equation are carefully considered, along with convective Nield boundary conditions, enabling a comprehensive analysis. By introducing dimensionless variables, the study transforms the partial differential equation into ordinary equations, facilitating the application of the shooting scheme to approximate the solution. The meticulously examined results offer detailed insights into temperature, velocity and mass concentration profiles, highlighting the profound influence of thermal radiation on these parameters. Furthermore, a comprehensive graphical presentation of each engineering parameter is provided, offering a nuanced understanding of the intricate physical phenomena involved, with particular attention to the influence of thermal radiation.

In the present work, we examine the dynamical behaviour of holographic dark energy (HDE) within the framework of modified f(R) gravity in a hypersurface-homogeneous space-time. To explore the universe's evolutionary behaviour under the influence of dark energy, we consider both exponential and power-law expansions. The cosmic evolution is analysed using standard cosmological diagnostics, including the density parameter and equation of state (EoS) parameter along with the deceleration parameter. Furthermore, the statefinder diagnostic pair is tested to detect precisely different phases of the universe. The squared speed of sound parameter was used to incorporate the stability analysis for our models. This investigation links the principles of quantum gravity to cosmology, producing testable predictions for forthcoming research and illustrating that HDE functions as a credible alternative to ΛCDM.

This work presents a comprehensive theoretical and experimental study of the behavior of nickel impurity atoms in the silicon crystal lattice. The focus is on analyzing diffusion mechanisms, the energetic characteristics of interstitial nickel atoms, their interaction with defects and other impurities, as well as the formation of stable clusters within the crystal volume. First-principles quantum mechanical modeling was employed using the QuantumATK software, applying the Linear Combination of Atomic Orbitals (LCAO) method and the Local Density Approximation (LDA) exchange-correlation functional. Special attention was given to calculating the binding energy of nickel atoms in interstitial sites and estimating the activation energy for their migration along various crystallographic directions ([100] and [010]). The modeling results revealed that nickel atoms predominantly diffuse in interstitial positions with an activation energy around 0.31 eV, which aligns well with previously reported experimental data. It was found that interactions of nickel with oxygen, carbon impurities, and point defects have a minimal impact on diffusion processes. However, interactions with vacancies lead to the formation of stable nickel silicides and cause an increased concentration of nickel near the surface. The experimental part of the study confirmed the formation of nickel clusters under high-temperature treatments. Scanning Electron Microscopy (SEM), Secondary Ion Mass Spectrometry (SIMS), and Infrared (IR) microscopy revealed a high density and uniform distribution of clusters throughout the crystal volume. Cluster sizes ranged from 20 to 100 nm, with concentrations reaching approximately 1010 cm-3. These findings demonstrate that nickel acts as an effective gettering impurity, enhancing the electrophysical properties of silicon. The results provide valuable insights for optimizing the fabrication processes of high-efficiency silicon solar cells and microelectronic devices.

Ensuring optimization of the radiation treatment process of experimental samples at electron accelerators and effective prediction of the results of the interaction of electron beams with irradiation objects requires the most accurate information about the characteristics of the beams. The initial (primary) characteristics of accelerator electron beams during transportation to irradiation objects will change due to their interaction with the external environment (air). Thus, secondary particles are also generated - bremsstrahlung photons, which also interact with samples. The paper presents the results of studies on modeling the influence of air layers on the change in the initial characteristics of electron beams during their transportation to irradiation objects and on the parameters of the generated bremsstrahlung photon fluxes in the plane of placement of experimental samples. The studies used the Monte Carlo code ‒ GEANT4. The modeling was carried out for the electron accelerator of the IEP NAS of Ukraine - the M-30 microtron, taking into account its technical parameters. The results of studies of the characteristics (energy spectrum, their integral values, transverse distributions in the 10×10 cm plane) of the electron beam and secondary photons at the output of the electron accelerator are presented. The influence of the thicknesses of the air layers (0.1÷500 cm) between the electron output unit and the potential plane (100×100 cm) of the placement of experimental samples for irradiation on the characteristics of the primary electron beams and generated bremsstrahlung photons (for the energy range of 6÷20 MeV) is studied.

Tandem solar cells based on hybrid organic–inorganic metal halide perovskites have achieved power conversion efficiencies of up to 28%. However, issues related to long-term stability and lead (Pb) toxicity have prompted the search for earth-abundant, chemically stable, and non-toxic alternatives. In this work, we report the first vacuum evaporation synthesis of BaZrS₃ (barium zirconium sulfide) thin films at a substrate temperature of 550 °C. The resulting films exhibit near-stoichiometric Ba:Zr ratios and strong light absorption, with absorption coefficients exceeding 10⁵ cm⁻¹ near 1.9 eV. Under controlled conditions, a baseline oxygen content of 4–6% was consistently observed. The absence of an additional sulfurization step markedly increased the resistance of the thin film and suppressed the dark current by approximately three orders of magnitude, indicating a substantial reduction in carrier density likely resulting from a decreased concentration of sulfur vacancies. These findings highlight the potential of BaZrS3 as a stable, lead-free absorber for next-generation photovoltaics.

Analytical expressions are obtained that describe the nonparaxial diffraction in free space of the TM01 mode with radial polarization of the field of the dielectric waveguide resonator of a terahertz laser during its interaction with a spiral phase plate with different topological charge (n). The physical features of the obtained vortex beams during their propagation and tight focusing are studied by numerical simulation. The integral diffraction Rayleigh-Sommerfeld transforms are used to simulate the propagation and focusing of the obtained beams. In free space the use of the spiral phase plate at the waveguide output with a topological charge of n = 1 leads to a change in the transverse beam profile from annular to a beam that has a field maximum on the axis, and then for n = 2 again to annular. During focusing the transverse distribution of the total field intensity in the absence of a spiral phase plate has a ring structure. In this case there is a slight intensity on the axis due to the contribution of the longitudinal component of the field. The transverse profile of the beam changes in the same way as during its propagation when using a phase plate. In this case the phase front changes from spherical to spiral with the presence of two (n = 1) and four (n = 2) branching vortices.

In this paper, the principle of corresponding states was used when conducting a comparative analysis of the temperature dependences of the isobaric heat capacity of aliphatic alcohols and their fluorosubstituted analogues. For the heat capacity, both literature experimental data and simulated data, obtained using artificial neural networks, were applied. The isobaric heat capacity for the aliphatic alcohols in the absolute values in a wide temperature range at constant pressure is smaller than that for the corresponding fluorosubstituted analogues. The comparison of the heat capacity data on the aliphatic alcohols and their fluorosubstituted analogues with the heat capacity of water, for which there is a hydrogen bond network, and comparison of the corresponding data with the heat capacity of hydrogen peroxide, where there are hydrogen bonds, but the network is absent, indicates that the change in the physical properties of alcohols upon fluorosubstitution is associated with the hydrogen bond density.

In a non-relativistic framework the mass spectra of cĉ, cc, ccc and ccu systems are investigated. The potential consists of the Cornell potential along with a logarithmic correction term as suggested from lattice QCD. We analyze the S, P, and D wave charmonium states and, S and P wave cc diquark states and have compared them with existing results from experiments and other potential models. Using the quark-diquark model, we have evaluated the S-wave spectra of doubly charmed baryon Ξ++cc and the triply charmed baryon Ωccc. These masses are compared with other theoretical studies.

The quaternary general form A2BCX4-based semiconducting materials with Kesterite-type structures are promising candidates for thin film-based solar cell devices. We examined the structural, electrical, optical, elastic, thermodynamic, and thermoelectric characteristics of Cu2ZnSnX4 (X = S, Se) using the FP-LAPW technique with an implanted Wien2k code. The Burke-Ernzerhof-generalized gradient approach (PBE-GGA) and Trans-Blaha modified Becke-johnson (TB-mBJ) are used to manage the exchange and correlation potentials. The results shows that Cu2ZnSnS4 and Cu2ZnSnSe4 compounds have stable structures with direct bands at 1.51 eV and 1.29 eV, respectively. The optical characteristics of these compounds were estimated using the dielectric function, allowing for an analysis of their reflectivity, refractive index, and absorption. Elastic parameters such as the Bulk, Young, Pugh, and Poisson ratios demonstrate that they are ductile and can be formed as thin films, a significant characteristic of Photovoltaic applications. Furthermore, we calculated various thermodynamic parameters entropy, and constant volume under pressure and temperature. We also determined the Cu2ZnSnX4 (X = S, Se) exhibits good thermoelectric performance concerning the figure of merit at 300K which is nearly unity. According to our findings, these materials are viable candidates for future clean green solar energy applications.

This study examines the effects of magnetically quantized degenerate trapped electrons and positrons on small-amplitude ion acoustic shock waves (IAShWs) in a pair ion plasma using the Zakharov-Kuznetsov Burger (ZKB) equation. It focuses on how factors like magnetic quantization, degenerate temperature, normalized negative ions, electrons, positrons, anisotropic pressure, and other relevant physical parameters from an astrophysical plasma environment influence the propagation of IAShWs, particularly in the nonlinear regime. This research explores that there exist two distinct wave propagation modes—subsonic and supersonic which shows few distinct characteristics in different physical plasma environment of astrophysical origin. The results could aid in understanding the nonlinear dynamics and wave propagation characteristics in superdense plasmas found in white dwarfs and neutron stars, where the effects of trapped electrons and positrons, as well as ionic pressure anisotropy, are significant which is yet to be explored in detail.