International Journal of Physics | Vol. 12, No. 6, June 2021 | pp. 41–48
DOI: 10.46882/2021/IJP/000134
Research Article
Title: Finite Element Modeling of Acoustic Wave Scattering and Tunable Attenuation in Porous Magnetorheological Elastomers
Names of Authors: P. J. O’Connor¹, G. S. Campbell²
Authors’ Affiliations:
¹ Department of Civil and Environmental Engineering, University College Cork, Cork, Ireland
² Research School of Physics and Engineering, Australian National University, Canberra, Australia
Abstract: Controlling acoustic wave transmission paths and focal spots in dense underwater and mechanical structural systems is vital for developing smart noise barriers, specialized non-destructive evaluation systems, and adaptive shock absorption components. This paper introduces a comprehensive finite element modeling framework to simulate acoustic wave scattering profiles and track tunable attenuation properties inside porous magnetorheological elastomer matrices. The mathematical approach links Biot's dynamic equations of poroelasticity with an empirical magneto-elastic constitutive setup to capture material responses under variable external magnetic fields. Numerical simulations were executed across an acoustic sweep from 20.0 kHz to 500.0 kHz. The models demonstrate that adjusting the external magnetic flux density induces a significant change in the material's shear modulus tensor, creating a tunable attenuation peak for the fast compressional wave mode at 185.0 kHz. This damping region can be shifted continuously by 38.0% across the frequency spectrum via external field adjustments. Experimental verification used 3D-printed porous elastomer specimens enriched with iron nanoparticles, matching the numerical attenuation data within a ±5.0% margin.
Keywords: Acoustic metamaterials; finite element modeling; magnetorheological elastomers; Biot's theory; wave scattering; tunable attenuation
Manuscript Timeline: Received: March 02, 2021; Revised: April 14, 2021; Accepted: May 02, 2021; Published: June 15, 2021
Citation: O’Connor, P. J., & Campbell, G. S. (2021). Finite Element Modeling of Acoustic Wave Scattering and Tunable Attenuation in Porous Magnetorheological Elastomers. International Journal of Physics, 12(6), 41–48.
International Journal of Physics | Vol. 12, No. 5, May 2021 | pp. 33–40
DOI: 10.46882/2021/IJP/000133
Research Article
Title: Fluid Inflow Velocity Mapping and Magnetic Reconnection Energetics in Solar Coronal Loop Interactions
Names of Authors: G. R. Davies¹, C. H. Jenkins²
Authors’ Affiliations:
¹ School of Physics and Astronomy, University of St Andrews, St Andrews, UK
² Space Sciences Laboratory, University of California, Berkeley, California, USA
Abstract: High-temperature magnetic reconnection stands as the core magnetohydrodynamic process fueling energy release dynamics in the solar atmosphere, shaping solar winds and spawning coronal mass ejections. This research maps fluid inflow velocity channels and maps reconnection energetics across interacting coronal loop structures using high-resolution extreme ultraviolet spectrographs on satellite clusters. We monitored the Doppler lines and line-intensity profiles belonging to the Fe XIV and Fe XXIII ionic markers to isolate active energy transformation sites within dense plasma environments. The empirical records confirm localized plasma inflows moving at 16.5 km/s, while directed shock outflows hit velocities of 295.0 km/s along the magnetic boundary lines. Using these transport indices, the localized non-dimensional reconnection rate was determined to fall between 0.05 and 0.08. These values confirm fast magnetic dissipation fields matching Petschek models extended for Hall current layers and plasmoid tearing networks. High-resolution line-broadening diagnostics indicate localized turbulent temperature regions hitting 9.8 MK inside the current diffusion sheet, confirming rapid viscous dissipation events.
Keywords: Solar atmosphere; magnetic reconnection; extreme ultraviolet; plasma velocity; solar flares; magnetohydrodynamics
Manuscript Timeline: Received: February 11, 2021; Revised: March 24, 2021; Accepted: April 10, 2021; Published: May 17, 2021
Citation: Davies, G. R., & Jenkins, C. H. (2021). Fluid Inflow Velocity Mapping and Magnetic Reconnection Energetics in Solar Coronal Loop Interactions. International Journal of Physics, 12(5), 33–40.
International Journal of Physics | Vol. 12, No. 4, April 2021 | pp. 25–32
DOI: 10.46882/2021/IJP/000132
Research Article
Title: Quantum Efficiency Optimization of Formamidinium Lead Iodide Perovskite Solar Cells via Graded Halide Profiling
Names of Authors: H. K. Tanaka¹, S. P. McCarthy²
Authors’ Affiliations:
¹ Department of Quantum Engineering, Nagoya University, Nagoya, Japan
² European Organization for Nuclear Research (CERN), Geneva, Switzerland
Abstract: Perovskite photovoltaic cells provide an efficient, low-cost architectural layout for building next-generation multi-junction solar harvesters. This investigation details a comprehensive numerical model to optimize the internal quantum efficiency of formamidinium lead iodide (FAPbI3) perovskite solar cells by incorporating a graded halide structural design. We simulated charge collection parameters, radiative decay dynamics, and interface traps under standard single-sun illumination matrices (AM 1.5G, 100.0 mW/cm²). The calculations demonstrate that introducing a continuous spatial gradient across the iodine-to-bromine chemical ratio induces a linear bandgap tilt (ranging from 1.48 eV to 1.75 eV), generating a built-in electric drift field. This local field quickens electron-hole separation tracks and depresses non-radiative Shockley-Read-Hall recombination events. Incorporating a baseline bulk carrier lifetime parameter of 25.0 ns, the optimized graded device configuration delivers a short-circuit current density of 26.2 mA/cm² and an open-circuit voltage reading of 1.14 V. This architecture secures a peak power conversion efficiency of 22.8%, yielding a significant improvement over the uniform bandgap reference cell.
Keywords: Perovskite solar cells; graded bandgap; quantum efficiency; charge transport; numerical modeling; photovoltaics
Manuscript Timeline: Received: January 08, 2021; Revised: February 18, 2021; Accepted: March 05, 2021; Published: April 12, 2021
Citation: Tanaka, H. K., & McCarthy, S. P. (2021). Quantum Efficiency Optimization of Formamidinium Lead Iodide Perovskite Solar Cells via Graded Halide Profiling. International Journal of Physics, 12(4), 25–32.
International Journal of Physics | Vol. 12, No. 3, March 2021 | pp. 17–24
DOI: 10.46882/2021/IJP/000131
Research Article
Title: Thermal Dispersion Metrics and Phonon Wavepacket Scattering Dynamics across Graphene-Boron Nitride Junctions
Names of Authors: D. W. Meyer¹, J. R. Weber²
Authors’ Affiliations:
¹ Institute of Physics, Karlsruher Institut für Technologie, Karlsruhe, Germany
² Physik-Department, Technische Universität München, Garching, Germany
Abstract: Maximising thermal dissipation metrics across low-dimensional heterostructures is an engineering priority for managing hotspots inside next-generation high-frequency field-effect transistors and optoelectronic microchips. This paper details molecular dynamics simulations aimed at quantifying thermal dispersion parameters and mapping acoustic phonon wavepacket scattering dynamics across graphene-boron nitride (Gr-hBN) lateral junctions. Atomistic lattices were constructed with the optimized Tersoff empirical potentials, containing varying structural configurations of boundary mismatch lines and localized point vacancy defects. Longitudinal and transverse acoustic phonon wavepackets were launched across a high-frequency grid centered between 2.0 THz and 12.0 THz. The computational models prove that high-frequency acoustic phonons (f greater than 6.0 THz) face severe diffuse scattering patterns at defective junction planes, dropping the calculated transmission coefficient from 0.78 down to 0.16. This thermal resistance stems from localized strain profiles and interface-confined vibrational resonance modes. The composite interface thermal conductance fell by 52.0% when boundary defect percentages were adjusted from 1.0% to 5.0% at 300.0 K, revealing atomic constraints for nanoscale heat management.
Keywords: Thermal conductance; phonon wavepacket; molecular dynamics; interface defects; graphene; boron nitride
Manuscript Timeline: Received: December 14, 2020; Revised: January 20, 2021; Accepted: February 08, 2021; Published: March 15, 2021
Citation: Meyer, D. W., & Weber, J. R. (2021). Thermal Dispersion Metrics and Phonon Wavepacket Scattering Dynamics across Graphene-Boron Nitride Junctions. International Journal of Physics, 12(3), 17–24.
International Journal of Physics | Vol. 12, No. 2, February 2021 | pp. 9–16
DOI: 10.46882/2021/IJP/000130
Research Article
Title: Relativistic Hydrodynamic Modeling of Collective Elliptic Flow Fluctuations in Asymmetric Neon-Gold Collisions
Names of Authors: S. C. O’Brien¹, L. M. Dupont²
Authors’ Affiliations:
¹ School of Physics, University College Dublin, Dublin, Ireland
² Laboratoire de Geologie de Lyon, Ecole Normale Superieure de Lyon, Lyon, France
Abstract: High-energy asymmetric heavy-ion interactions generate miniature high-density subatomic interaction volumes that allow researchers to map out the minimal spatial boundaries required to establish liquid-like quark-gluon plasma states. This paper implements a relativistic hydrodynamic modeling framework to simulate multi-particle production cascades and measure elliptic flow fluctuations during asymmetric neon-gold (Ne-Au) collision events. We carried out numerical runs using a 3+1 dimensional viscous hydrodynamic code matched to a statistical hadronization processing module to evaluate final-state momentum metrics. The initial geometric configurations were derived via a Monte Carlo Glauber scheme to capture localized sub-nucleon density fluctuations. The simulations demonstrate that the high-acceleration expansion profile builds a large radial flow signature, boosting the average transverse momentum parameters of emerging kaons up to 1.15 GeV/c in central runs. The simulated elliptic flow index (v²) showcases a clear mass-ordering trend, matching tracking statistics compiled by heavy-ion detectors within a tight ±5.2% accuracy margin. This behavior proves that intermediate asymmetric collision tracks can support brief, fluid-like collective hydrodynamic expansions.
Keywords: Relativistic hydrodynamics; quark-gluon plasma; elliptic flow; asymmetric collisions; Glauber model; statistical hadronization
Manuscript Timeline: Received: November 02, 2020; Revised: December 18, 2020; Accepted: January 11, 2021; Published: February 12, 2021
Citation: O’Brien, S. C., & Dupont, L. M. (2021). Relativistic Hydrodynamic Modeling of Collective Elliptic Flow Fluctuations in Asymmetric Neon-Gold Collisions. International Journal of Physics, 12(2), 9–16.
International Journal of Physics | Vol. 12, No. 1, January 2021 | pp. 1–8
DOI: 10.46882/2021/IJP/000129
Research Article
Title: Kinetic Characterisation of Electron Transport Swarms and Dissociation Kinetics in Ammonia-Hydrogen Plasmas
Names of Authors: D. L. Santos¹, S. H. Zhang²
Authors’ Affiliations:
¹ Department of Physics, University of Coimbra, Coimbra, Portugal
² Department of Physics, Tsinghua University, Beijing, China
Abstract: Ammonia-hydrogen (NH3-H2) gas mixtures are heavily utilized across the metallurgical processing and microelectronics manufacturing sectors for nitride passivation, steel hardening, and high-purity semiconductor crystal deposition. This paper presents a self-consistent kinetic characterisation of electron transport swarms and evaluates molecular dissociation paths in low-pressure ammonia-hydrogen discharges. We calculated solution profiles for the electron Boltzmann equation using a multi-term spherical harmonic expansion engine across an expansive reduced electric field range (E/N) spanning 5.0 Td to 600.0 Td. The cross-section matrix items detailed elastic momentum shifts, rotational transitions, vibrational pumping, dissociative attachment, and direct electronic impact ionization events. The calculations reveal that adding small ammonia quantities (from 2.0% to 15.0% by volume) strongly skews the high-energy profile of the electron energy distribution function. At a marker of E/N = 50.0 Td, the total amidogen (NH2) radical generation rate coefficient scales up by an order of magnitude, driven by intense energy confinement near the primary vibrational impact boundaries. The simulated drift velocity constants match independent experiment recordings within a minor ±4.8% variation.
Keywords: Ammonia plasmas; Boltzmann equation; electron transport; dissociation kinetics; plasma processing; cross-section
Manuscript Timeline: Received: October 12, 2020; Revised: November 24, 2020; Accepted: December 15, 2020; Published: January 14, 2021
Citation: Santos, D. L., & Zhang, S. H. (2021). Kinetic Characterisation of Electron Transport Swarms and Dissociation Kinetics in Ammonia-Hydrogen Plasmas. International Journal of Physics, 12(1), 1–8.