Volume 70, Issue 2

The nuclear reaction of deuterium–tritium (D–T) fusion by the usual magnetic or inertial confinement suffers from a number of difficulties and problems caused by tritium handling, neutron damage to materials and neutron-induced radioactivity, etc. The study of the nuclear synthesis reaction of deuterium–helium-3 (D– 3 He) at low collision energies (below 1 keV) is of interest for its applications in nuclear physics and astrophysics. Spherical tokamak (ST) reactors have a low aspect ratio and can confine plasma with β ≈1. These capabilities of ST reactors are due to the use of the alternative D– 3 He reaction. In this work, the burn condition of D– 3 He reaction was calculated by using zero-dimensional particles and power equations, and, with the use of the parameters of the ST reactor, the stability limit of D– 3 He reaction was calculated and then the results were compared with those of D–T reaction. The obtained results show that the burn conditions of D– 3 He reaction required a higher temperature and had a much more limited temperature range in comparison to those of D–T reaction.

In this study, we obtain the approximate analytical solutions of the radial Schrödinger equation for the Deng–Fan diatomic molecular potential by using the exact quantisation rule approach. The wave functions were expressed by hypergeometric functions via the functional analysis approach. An extension to the rotational–vibrational energy eigenvalues of some diatomic molecules is also presented. It is shown that the calculated energy levels are in good agreement with those obtained previously ( E nℓ – D ; shifted Deng–Fan).

The structures, stabilities, and electronic properties of rare-earth lanthanum doped gold La 2 Au n ( n = 1–9) and pure gold Au n ( n ≤ 11) clusters have been investigated by using density functional theory. The optimized geometries show that the lowest energy structures of La 2 Au n clusters favour the 3D structure at n ≥ 3. The lanthanum atoms can strongly enhance the stabilities of gold clusters and tend to occupy the most highly coordinated position. By analysing the gap, vertical ionization potential, and chemical hardness, it is found that the La 2 Au 6 isomer possesses higher stability for small-sized La 2 Au n clusters ( n = 1–9). The charges in the La 2 Au n clusters transfer from La atoms to the Au n host. In addition, Wiberg bond indices analysis reveals that the intensity of different bonds of La 2 Au n clusters exhibits a sequence of La–La bond > La-Au bond > Au–Au bond.

In this article, we investigated a generalised scalar field cosmology characterised by a time-dependent coupling function, a time-dependent cosmological constant, a chameleonic field, and a time-dependent equation of state parameter. Based on a particular choice of the Hubble parameter as function of the scalar field and its time derivative, we have investigated the dynamics of the Friedmann–Robertson–Walker flat universe. We have observed that for a particular choice of the free parameters in the theory, the universe accelerates with time and asymptotically tends toward a static universe. For specific values of the free parameters, the asymptotically static universe may be dominated by phantom energy or a cosmological constant without the need to implement in the theory multiple scalar fields or additional interactions. It is also pointed out that an asymptotically static universe is as well one special class of solutions for Horndeski and generalised galileons cosmologies. Special properties and features are discussed accordingly.

We have studied the Rashba spin-orbital effect on a diluted magnetic semiconductor (DMS) quantum well with parabolic potential in the presence of a magnetic field parallel to the z axis, taking into account the Zeeman coupling and the s-d exchange interaction between the carriers and the magnetic ions. We have obtained an analytical expression for the electron energy spectrum, which depends on the magnetic ion concentration, temperature, and strength of magnetic field. By using the obtained energy spectrum, we calculated the electron effective g *-factor. We have found that effective g *-factor increases when the magnetic field increases; by increasing the strength of spin-orbit interaction, the electron g *-factor decreases and by increasing the temperature, the electron g *-factor increases.

Influence of a spatially varying magnetic field on Fe 3 O 4 -plasma nanofluid flow in a vessel as a targeted drug delivery system is investigated. Combined effects of ferrohydrodynamic (FHD) and magnetohydrodynamic (MHD) are considered in mathematic models. The lattice Boltzmann method is applied to solve the governing equations. Effects of active parameters, such as the Reynolds number and magnetic number on the flow characteristics, have been examined. Results indicate that the presence of the magnetic field affects considerably the flow field. Back flow occurs near the region where the magnetic source is located. Also, it can be found that the skin friction coefficient is a decreasing function of the Reynolds number and magnetic number.

Peristaltic transport of water-based nanofluids in the presence of applied magnetic field is studied. Two different types of nanofluids (silver-water and copper-water nanofluids) are used in the analysis. Effects of mixed convection, viscous dissipation, Joule heating, and heat generation/absorption are considered. Long wavelength and low Reynolds number approximations are used in the mathematical modelling. Numerical solutions are obtained for the velocity, pressure gradient, pressure rise per wavelength, temperature, and heat transfer rate at the wall. Physical quantities of interest are studied through graphs and tables. Comparison of water, silver-water, and copper-water nanofluid is presented. Results show that velocity and temperature of ordinary water are larger than those of nanofluids. Maximum velocity, temperature, and heat transfer rate at the wall of silver-water nanofluid is relatively higher than the copper-water nanofluid.

The electrical conductivity of molten ZnCl 2 was measured in a wide temperature range (Δ T =863 K) to a temperature as high as 1421 K that is 417 degrees above the boiling point of the salt. At the temperature maximum of the own vapor pressure of the salt reached several megapascals.