Open Access Original Research Article

Dynamics of Multiple Slip and Thermal Radiation on Hydromagnetic Casson Nanofluid Flow over a Nonlinear Porous Stretchable Surface

O. E. Omotola, E. O. Fatunmbi

Physical Science International Journal, Page 1-14
DOI: 10.9734/psij/2021/v25i430249

Aims/ Objectives: This paper examines the dynamics of multiple slip together with thermal radiation effects on the transport of a magnetohydrodynamic Casson nanofluid passing a nonlinear porous stretchable sheet in the existence of viscous dissipation and chemical reaction.
Study Design: Cross-sectional study. Methodology: The outlining equations modeling the transport phenomenon are simplified into nonlinear ordinary differential equations via the approach of similarity transformations and subsequently analyzed numerically by shooting techniques alongside Runge-Kutta Fehlberg scheme.
Results: The outcomes of decisive parameters affecting the flow, heat, and nanoparticle concentration are graphically deliberated. From the investigation, it is revealed that Brownian motion, viscous dissipation, and thermophoresis parameters augment the thermal boundary layer and propel an upward growth in the temperature profile. Furthermore, the slip factor decelerates the flow and heat dissipation while the fluid movement drags in the existence of the magnetic field.

Conclusion: The results obtained in this study compared favourably well with existing related studies in literature under limiting scenarios.

Open Access Original Research Article

Depth of Space and Radius of the Electron

Stefan von Weber, Alexander von Eye

Physical Science International Journal, Page 15-31
DOI: 10.9734/psij/2021/v25i430250

The cosmological model of the expanding balloon in 4D-space (CM) delivers in interaction with a homogeneous vector field exactly Newton’s law of gravitation with its 1/r-shape of the gravitational funnel. So far, the depth of space, W, in the 4-th spatial dimension can only be calculated using the theoretical approach of Feynman’s radius of excess rex=a/3 with Schwarzschild-radius a. With this, the connection to the general theory of relativity (GR) is established, but the situation is unsatisfactory. In the present study, the possibilities of an experimental approach to the calculation of spatial depth, W, are explored. The only experimental approach so far is the bending of light on a central mass. We hypothesize in addition to the main effect φ = -4a/y, i.e., the angle of diffraction of a light beam on a heavy central mass in the distance y and with Schwarzschild-radius a, an additional effect close to the center of the form φC ~ -1/y4. This additional effect has on the edge of the central mass about 1/3 of the strength of the main effect. However, its influence disappears very quickly with increasing distance. For this reason the sun cannot be used as the central mass. The bright corona and the strong magnetosphere do not allow measurements close to the sun. However, ESA’s GAIA mission puts the planet Jupiter at the center of interest. This spacecraft measures with extremely high precision the positions of billions of stars. Results of first data analyses have already been published. As a side effect - the application of the CM to small particles provides an indication that the radius of the electron could be in the order of 10-23 m.

Open Access Original Research Article

Structural, Electronic and Optical Properties of Stanene Doped Beryllium: A First Principle Study

L. S. Taura, Isah Abdulmalik, A. S. Gidado, Abdullahi Lawal

Physical Science International Journal, Page 32-40
DOI: 10.9734/psij/2021/v25i430251

Stanene is a 2D hexagonal layer of tin with exceptional electronic and optical properties. However, the semiconductor applications of stanene are limited due to its zero band-gap. However, doping stanene could lead to a band gap opening, which could be a promising material for electronic and optical applications. In this work, optimized structure, electronic band structure, real and imaginary parts of the frequency-dependent dielectric function, electron loss function, and refractive index of stanene substitutionally doped with alkaline earth metal (beryllium) were analyzed using density functional theory (DFT) calculations as implemented in the quantum espresso and yambo suites. A pure stanene has a zero band gap energy, but with the inclusion of spin-orbit coupling in the electronic calculation of pure stanene, the band-gap is observed to open up by 0.1eV. Doping stanene with beryllium opens the band-gap and shifts the Dirac cone from the Fermi level, the band gap opens by 0.25eV, 0.55eV, and 0.8eV when the concentration of Beryllium is 12.5%, 25%, and 37.5% respectively. The Dirac cone vanished when the concentration of the dopant was increased to 50%.  The Fermi level is shifted towards the valence band edge indicating a p-type material. The material absorption shows that SnBe absorption ranges in the visible to the ultraviolet region, The refractive index in stanene doped beryllium (SnBe) was found to be higher than that of pristine stanene, the highest refractive index was 9.2 at SnBe25%. In a nutshell, the results indicate that stanene can be a good material for electronic and optical applications if doped with beryllium.

Open Access Original Research Article

A Review of the Bohr’s Model of Hydrogen Atom

Robert Wilson

Physical Science International Journal, Page 41-45
DOI: 10.9734/psij/2021/v25i430252

In this paper, the classical Bohr’s model of the hydrogen atom has been revisited. Two values of fundamental physical properties of an electron in the hydrogen atom has been identified. These physical properties ( & ) are constant in nature. The aim for the review was to contribute to the solution of disagreement between the Bohr’s wavelength ( ) and the Balmer’s experimental observation ( ) for the emission spectrum of hydrogen atom. There are two other constants  and  that were identified in the Bohr’s equation of the hydrogen atom.

The four fundamental physical constants are intrinsic properties of an electron and can be applied to multi-electron system. They can also be obtained from Schrodinger’s equation for hydrogen atom at steady state. These constants may be subjected to scrutiny for their determination for better understanding. Also, since Bohr’s model of hydrogen atom is based on classical mechanics, this paper has provided an alternate method of solving simple problems in atomic physics under Bohr’s model to aid good mental picture of hydrogen atom to scientists.

Open Access Original Research Article

Self-Organization of Charged Particles in an Electric Field

William J. B. Oldham Jr.

Physical Science International Journal, Page 46-62
DOI: 10.9734/psij/2021/v25i430253

Self-organization in small systems of particles with simple dynamic laws has been simulated. The purpose of this work was to investigate self-organization in small systems of charged particles under the influence of an electric field where we could follow individual particles. There are positively and negatively charged particles. The intention is to look for pattern formation as the system evolves. Three electric fields and the particle-to-particle interactions were utilized to provide the forces. The three electric fields were a constant field, a ramp field, and an oscillatory field. The final system states for various electric fields are presented. For the two kinds of particles simulated, like particles have a repulsive force, while unlike particles have an attractive force. Initially, the particles are randomly distributed in a two dimensional square bounded region, and then allowed to dynamically interact for a number of iterations. Using the inverse square law force, modified at short distances, most cases resulted in equilibrium with the particles of opposite polarity paired up. Since this was a state of equilibrium no more movement occurred. The results of the experiments are presented in graphical format. The main conclusions are that this model can be used to study small dynamic systems, and that the presence of an external electric field does not significantly modify the final configuration but hastens the development of the equilibrium state.