Now it is well recognized that although Jansky discovered radio astronomy at decametric wavelengths, the quest for higher angular resolution and the difficulties in handling ionospheric effects have left the low frequency (below 150 MHz) spectrum poorly explored. This is despite many unique astrophysical questions that can be better addressed at low frequencies, and problems requiring accurate ...

This research paper studies the fracture and mechanical properties of rippled graphene containing dislocation dipoles. The atomistic simulation is performed to study deformation behavior pristine defective wrinkled graphene. Graphene wrinkling considerably decreases ultimate tensile strength with without defects but increases strain. For dipoles, temperature increase slightly affects properties...

Purpose To develop an unshielded dipole transceiver array for human head imaging at 9.4 Tesla and to improve decoupling of adjacent elements, a novel design with modified passive antennas was developed, evaluated, tested. Methods The new consisted 8 bent folded-end elements placed in single row surrounding the head. Adjacent RF arrays are usually decoupled by introducing circuits electrically c...

Using the sampled data of a desired pattern is a common technique in pattern synthesizing of array factor (AF) of antenna arrays. Based on the obtained data matrix, Least Square Method (LSM) is used to calculate the exciting coefficient of array elements. The most important parameter, which involves the accuracy and complexity of calculation, is the sampling rate of the desired pattern. Classic...