Part 2: Spatially Dispersive Metasurfaces - IE-GSTC-SD Field Solver with Extended GSTCs

<div>An Integral Equation (IE) based field solver to compute the scattered fields from spatially dispersive metasurfaces is proposed and numerically confirmed using various examples involving physical unit cells. The work is a continuation of Part-</div><div>1 [1], which proposed the basic methodology of representing spatially dispersive metasurface structure in the spatial frequency domain, k. By representing the angular dependence of the surface susceptibilities in k as a ratio of two polynomials, the standard Generalized Sheet Transition Conditions (GSTCs) have been extended to include the spatial derivatives of both the difference and average fields around the metasurface. These extended boundary conditions are successfully integrated here into a standard IE-GSTC solver, which leads to the new IEGSTC-SD simulation framework presented here. The proposed IE-GSTC-SD platform is applied to various uniform metasurfaces, including a practical short conducting wire unit cell, as a representative practical example, for various cases of finite-sized flat and curvilinear surfaces. In all cases, computed field distributions are successfully validated, either against the semi-analytical Fourier decomposition method or the brute-force full-wave simulation of volumetric metasurfaces in the commercial Ansys FEM-HFSS simulator.</div>

Part 2: Spatially Dispersive Metasurfaces - IE-GSTC-SD Field Solver with Extended GSTCs

<div>An Integral Equation (IE) based field solver to compute the scattered fields from spatially dispersive metasurfaces is proposed and numerically confirmed using various examples involving physical unit cells. The work is a continuation of Part-</div><div>1 [1], which proposed the basic methodology of representing spatially dispersive metasurface structure in the spatial frequency domain, k. By representing the angular dependence of the surface susceptibilities in k as a ratio of two polynomials, the standard Generalized Sheet Transition Conditions (GSTCs) have been extended to include the spatial derivatives of both the difference and average fields around the metasurface. These extended boundary conditions are successfully integrated here into a standard IE-GSTC solver, which leads to the new IEGSTC-SD simulation framework presented here. The proposed IE-GSTC-SD platform is applied to various uniform metasurfaces, including a practical short conducting wire unit cell, as a representative practical example, for various cases of finite-sized flat and curvilinear surfaces. In all cases, computed field distributions are successfully validated, either against the semi-analytical Fourier decomposition method or the brute-force full-wave simulation of volumetric metasurfaces in the commercial Ansys FEM-HFSS simulator.</div>

Scattering of Oblique Electromagnetic Waves by a Thin Conducting Wire Parallel to the Ambient Magnetic Field in a Non-Gyrotropic Plasma in the Resonance Frequency Range

&lt;p&gt;A problem of scattering of oblique plane electromagnetic waves propagating in a cold non-gyrotropic plasma in the resonance frequency range by a thin finite-length conducting wire parallel to the ambient magnetic field is considered. The solution to the scattering theory integral equation for the current induced on the wire surface as well as the scattering field and cross section are found and analyzed. The approach is based on the perturbation theory that takes into account the thin wire approximation generalized to the case of the anisotropic plasma. Special attention is paid to the case of highly oblique quasi-electrostatic waves which scattering characteristics are quite unique. The results are important for analysis of (a) reception of electromagnetic waves in the space plasma using antennas onboard spacecraft and (b) diffraction of electromagnetic waves by long field-aligned plasma density irregularities in planetary magnetospheres under certain conditions.&lt;/p&gt;&lt;p&gt;This work was supported by the Russian Science Foundation under grant 20-12-00268.&lt;/p&gt;

Experimental study on flame propagation over overload-wire under varying inclination Angle

To better understand the process of fire caused by conducting wire, based on the study of overload of the low-voltage wire, the theoretical analysis of flame spread mechanism of overload-wire was proposed, and the functional relationship between flame shape characteristics and flame spread speed, current, and inclination angle was studied. The results show that: (1) the theoretical model of flame propagation can well reflect the changes of thermodynamic parameters in the process of flame propagation, and it is in better agreement with the experimental results. (2) When the current value is constant, with the increase of the inclination angle of the wire (0°-90°), the flame is elongated along the wire direction, the width of the flame base increases, and the angle between the flame front and the wire decreases. When the inclination angle is fixed, with the increase of the inclination angle of the conductor, the flame shape becomes more "high and wide" and the flame height increases at the same time. (3) When the current is constant, the flame spread rate increases with the increase of wire inclination angle; when the inclination angle is constant, the flame spread rate decreases sharply with the increase of current.

Natural polymer-based bioabsorbable conducting wires for implantable bioelectronic devices

A bioabsorbable conducting wire with excellent conductivity, bioabsorbability, biocompatibility, and low weight provides the possibility to construct fully bioabsorbable implantable devices.

Examining the students’ understanding level towards the concepts of magnetic field: the case of conducting wire

The electromagnetism is one of the important topics in physics and it has quite a lot of applications in a wide range of area. It also examines the electromagnetic force researches that occur between the electrically charged particles. On the other hand, examination of the magnetic field around the conductors and the movement of the charged particles in the electromagnetic field is quite interesting topics on that the physics researchers intensively investigated. The electromagnetic theory has an abstract nature, because the university level students have many learning and understanding difficulties about the concepts related to these topics. In realization of meaningful learning, the role of the students’ prior knowledge about the aforementioned concepts is becoming important. This study aims to investigate the understanding of 12 pre-service physics teachers related to the concept of moving particles in an electromagnetic filed by using the qualitative research methods. The data collected through the test consisting of three question and it was analysed by using content analysis method. The understanding levels and the alternative conceptions of the pre-service physics teachers were determined by different categories at the end of the content analyses process. Keywords: Alternative conceptions, electromagnetism education, pre-service physics teachers; understanding level;

Sag and Tension of 275 kV Transmission Line using Catenary

This research will develop a catenary method to determine the sag and tension analysis on the 275 kV transmission line conductors. The catenary method is dependent on the equation of the weight of the conductor, the maximum tensile stress of the conducting wire, the length of the span, and the maximum sag of the conductor. The method will be used in determining the value of sag and tension with the design of the model using software AutoCAD. The results of research for the same tower sag height of 6.86 m, with a tension of 4610.83 kg and a conductor length of 401.06 m, while sag for the tower is not the same height of 8.14 m, with a tension of 4612.84 kg, and changes in conductor length 401.06 m. The increase in current causes the sag value to increase, when the minimum current sag value is 6.9828 m, and the maximum current sag value increases to 8.44 m. While the tension will decrease along so that temperature is increased the current minimum pressure of 4531.27kg, and at the time of maximum tension of 3749.728kg. Sag and tension are also affected by ambient temperature when the minimum temperature is 20 ℃ sags are 6.8621 m and when the maximum temperature is 40 ℃ sag increases to 7.793492 m. Tension will decrease with each increase in temperature when the minimum temperature is 20 ℃ tension 4610.538 kg when the maximum temperature is 40 ℃ the tension is reduced to 4062.345 kg.