A Simple Technique for Improving the Anechoic Performance of a Pyramidal Absorber

Abstract

In this paper, we propose a very simple technique that offers an extra degree of freedom to optimize the design of a tire dustbased absorber with reduced height. Cladding is a technique that is used to enhance the surface properties of a part, and it has been used in many applications for many years. In this technique, a clad layer is created on the core material, and the composition of the clad layer is adjusted to enhance the performance of the core material. We use a rice husk-clad layer to enhance the impedance matching characteristics of the low-loss, tire-dust core, microwave absorber. The overall design is a two-layer, geometrically-tapered, pyramidal structure composed of two lossy waste materials. Our main goal was to make the front surface less reflective (impedance matched), hence the material of the outer layer (clad) of the absorber was selected on the basis of the analysis of the dielectric properties of the candidate materials. Optimum thickness of the clad was obtained by using CST simulation software and found to be 12 mm, for which a reflectivity performance of less than −20 dB was

A New Facile Synthesis of Tungsten Oxide from Tungsten Disulfide: Structure Dependent Supercapacitor and Negative Differential Resistance Properties

“…The precursor material WS 2 powder shows two characteristic peaks at 352 and 422 cm −1 corresponding to E 1 2g (in-plane optical mode) and A 1g (out-of-plane vibration of the sulfur atoms) modes, respectively. [38,42] WO 3· H 2 O shows two characteristic peaks at 645 and 947 cm −1 , attributed to the stretching mode of WOH 2 and symmetric stretching of terminal (WO) groups, respectively. After thermal annealing, the peaks at 645 and 947 cm −1 completely disappear and new peaks at 264, 326, 700, and 796 cm −1 appear.…”

Schottky Contact in Monolayer WS2 Field‐Effect Transistors

“…Because the traditional substitute doping method is hard to realize in 2DSC FETs, contacting metals in a direct way becomes a commonly used way to inject carriers into the 2DSCs . Experimentally, Ni, Ti, Cr, Au, Pd, and graphene have been adopted as electrodes in WS 2 FETs . There are two kinds of interfaces in the FET configuration, as labeled in Figure : the one is the vertical interface (interface B) between metal and the underneath ML WS 2 , and the other is the lateral interface (interface D) between the electrode ML WS 2 and the channel ML WS 2 .…”

All-Optical Reversible Manipulation of Exciton and Trion Emissions in Monolayer WS2

“…Recently, unprecedented tunability of the optical properties of layered MX2 have been achieved both theoretically and experimentally. For example, by spinning coating p/n-type organic dopants (for instance, TCNQ and NADH molecules) or even biomolecules (such as DNA nucleobases) on monolayer MX2, 9,[14][15][16] the conversion among neutral exciton and positive or negative trion can be undoubtedly determined, although these manipulations are irreversible. The reversible electrostatic tunability of the exciton charging effects in monolayer MX2 has been realized by using field-effect transistor (FET) structure or molecular physisorption gating.…”