Radiation efficiency varying equivalent radiated power.

In this paper, an improved version of the classical equivalent radiated power (ERP) approximation is proposed based on principled physical arguments. A geometry-, frequency-, and vibration pattern-dependent approximation of radiation efficiency is developed and used as a corrective factor for the classical ERP approximation. The proposed method called "radiation efficiency varying equivalent radiated power" (revERP), is shown to greatly improve the accuracy of classical ERP at low Helmholtz numbers, while attaining the accuracy of classical ERP at high Helmholtz numbers.

Molecular Beam Epitaxy of Layered Group III Metal Chalcogenides on GaAs(001) Substrates.

Development of molecular beam epitaxy (MBE) of two-dimensional (2D) layered materials is an inevitable step in realizing novel devices based on 2D materials and heterostructures. However, due to existence of numerous polytypes and occurrence of additional phases, the synthesis of 2D films remains a difficult task. This paper reports on MBE growth of GaSe, InSe, and GaTe layers and related heterostructures on GaAs(001) substrates by using a Se valve cracking cell and group III metal effusion cells.

Design and Characterization of a Sharp GaAs/Zn(Mn)Se Heterovalent Interface: A Sub-Nanometer Scale View.

The distribution of magnetic impurities (Mn) across a GaAs/Zn(Mn)Se heterovalent interface is investigated combining three experimental techniques: Cross-Section Scanning Tunnel Microscopy (X-STM), Atom Probe Tomography (APT), and Secondary Ions Mass Spectroscopy (SIMS). This unique combination allowed us to probe the Mn distribution with excellent sensitivity and sub-nanometer resolution. Our results show that the diffusion of Mn impurities in GaAs is strongly suppressed; conversely, Mn atoms are subject to a substantial redistribution in the ZnSe layer, which is affected by the growth conditions and the presence of an annealing step.

The Green's matrix and the boundary integral equations for analysis of time-harmonic dynamics of elastic helical springs.

Helical springs serve as vibration isolators in virtually any suspension system. Various exact and approximate methods may be employed to determine the eigenfrequencies of vibrations of these structural elements and their dynamic transfer functions. The method of boundary integral equations is a meaningful alternative to obtain exact solutions of problems of the time-harmonic dynamics of elastic springs in the framework of Bernoulli-Euler beam theory.