REFLECTION COEFFICIENT OF AN ELECTROMAGNETIC WAVE IN CONDUCTIVE MEDIA

Within the ground penetrating radar bandwidth the medium is considered to be an ideal dielectric, which is not always true. Electromagnetic waves reflection coefficient conductivity dependence showed a significant role of the difference in conductivity in reflection strength. It was confirmed by physical modeling. Conductivity of geological media should be taken into account when solving direct and inverse problems, survey design planning, etc. Ground penetrating radar can be used to solve the problem of mapping of halocline or determine water contamination.

Aminopropyltrimethoxysilane-functionalized boron nitride nanotube based epoxy nanocomposites with simultaneous high thermal conductivity and excellent electrical insulation

An ideal dielectric epoxy nanocomposite with high thermal conductivity is successfully fabricated utilizing aminopropyltrimethoxysilane-functionalized BNNTs.

Quasi-freestanding epitaxial silicene on Ag(111) by oxygen intercalation

Silicene is a monolayer allotrope of silicon atoms arranged in a honeycomb structure with massless Dirac fermion characteristics similar to graphene. It merits development of silicon-based multifunctional nanoelectronic and spintronic devices operated at room temperature because of strong spin-orbit coupling. Nevertheless, until now, silicene could only be epitaxially grown on conductive substrates. The strong silicene-substrate interaction may depress its superior electronic properties. We report a quasi-freestanding silicene layer that has been successfully obtained through oxidization of bilayer silicene on the Ag(111) surface. The oxygen atoms intercalate into the underlayer of silicene, resulting in isolation of the top layer of silicene from the substrate. In consequence, the top layer of silicene exhibits the signature of a 1 × 1 honeycomb lattice and hosts massless Dirac fermions because of much less interaction with the substrate. Furthermore, the oxidized silicon buffer layer is expected to serve as an ideal dielectric layer for electric gating in electronic devices. These findings are relevant for the future design and application of silicene-based nanoelectronic and spintronic devices.

Ideal dielectric thermally conductive bismaleimide nanocomposites filled with polyhedral oligomeric silsesquioxane functionalized nanosized boron nitride

NH2–POSS functionalized nanosized boron nitride fillers were performed to fabricate thermally conductive bismaleimide/diallylbisphenol A (BMI/DABA) nanocomposites combining excellent dielectric properties and outstanding thermal stabilities.

Numerical Analysis of the Failure Modes for the Circular Dielectric Elastomer Actuator

The circular actuators of dielectric elastomer are a type of basic configurations [1]. A pre-stretched polymer film with an annulus electrode will be investigated in this work. The deformation along the radius was be proved to be inhomogeneous [2]. We study the inhomogeneous properties of circular ring actuators based on the ideal dielectric model and meanwhile obtain the failure modes of tension loss which will occur under different geometric parameters. For this type of circular actuator, the loss of tension will occur before electric breakdown. The method illustrated here is generic and can be applied to other complex circular configuration. The results will contribute to the further improvement of DE.