Encapsulated thermoacoustic projector based on freestanding carbon nanotube film

A suspended nanotube film (or films) producing sound by means of the thermoacoustic (TA) effect is encapsulated between two plates, at least one of which vibrates, to enhance sound generation efficiency and protect the film. To avoid the oxidation of carbon nanotubes at elevated temperatures and reduce the thermal inertia of surrounding medium the enclosure is filled with inert gas (preferably with high heat capacity ratio, γ=Cp/Cv, and low heat capacity, Cp). To generate sound directly as the first harmonic of applied audio signal without use of an energy consuming dc biasing, an audio signal modulated carrier frequency at much higher frequency is used to provide power input. Various other inventive means are described to provide enhanced projected sound intensity, increased projector efficiency, and lengthened projector life, like the use of infrared reflecting coatings and particles on the projector plates, non-parallel sheet alignment in sheet stacks, and cooling means on one projector side.Board of Regents, University of Texas Syste

Postcard: A Residence Scene on Superior Street, Plains, Kansas

This colorized photographic postcard of a row of houses promotes a residential area in Plains, Kansas. Each house is two stories tall and has a yard in front. A sidewalk in front of the houses starts in the foreground and ends in the background. There is printed text at the bottom of the card. There is printed text and handwriting on the back of the card.https://scholars.fhsu.edu/tj_postcards/1708/thumbnail.jp

Postcard: Best Wishes, Robert & Helen Baughman, 1966, Liberal Kansas

This color printed postcard features stamp collection materials on the bottom left of the card. The card contains a border of holly and poinsettias in green and red. Printed text is in the middle of the card. Printed text with black, green and red ink are on the back of the card. An illustration of green holly and a red poinsettia decorate the left and top of the card. Two emblems, one of the Society of Philatelic Americans and one of the Kansas Precancel Society are on the center of the card. Typed text is on the right side of the card.https://scholars.fhsu.edu/tj_postcards/1832/thumbnail.jp

Evidence for Braggoriton Excitations in Opal Photonic Crystals Infiltrated with Highly Polarizable Dyes

We studied angle-dependent reflectivity spectra of opal photonic crystals infiltrated with cyanine dyes, which are highly polarizable media with very large Rabi frequency. We show that when resonance conditions between the exciton-polariton of the infiltrated dye and Bragg frequencies exist, then the Bragg stop band decomposes into two reflectivity bands with a semi-transparent spectral range in between that is due to light propagation inside the gap caused by the existence of braggoriton excitations. These novel excitations result from the interplay interaction between the Bragg gap with spatial modulation origin and the polariton gap due to the excitons, and may lead to optical communication traffic inside the gap of photonic crystals via channel waveguiding.Comment: LaTex, 5 pages, 3 figures include