United States of America As Represented by the Administrator of Nasa

Maria A Kuczmarski

Robert A Miller

Michael G Jones

James C Johnston

Christopher J Miller

Lisa Danielle Koch

Peter J Bonacuse

Nicholas Leventis

Mary Ann B Meador

J Chris Johnston

Broadband acoustic absorbers may be capable providing good absorption performance between 0 and 3,000 Hz, and particularly below 1,000 Hz. Reeds may be incorporated in a single layer, multiple layers, or bundles. Such broadband acoustic absorbers may be applied for acoustic absorption in aircraft, spacecraft, residential and commercial buildings, vehicles, industrial environments, wind tunnels, or any other suitable environment or application where noise reduction is desired.

Broadband acoustic absorbers

A method and apparatus for the measurement of thermal conductivity combines the following capabilities: 1) measurements of very small specimens; 2) measurements of specimens with thermal conductivity on the same order of that as air; and, 3) the ability to use air as a reference material. Care is taken to ensure that the heat flow through the test specimen is essentially one-dimensional. No attempt is made to use heated guards to minimize the flow of heat from the hot plate to the surroundings. Results indicate that since large correction factors must be applied to account for guard imperfections when specimen dimensions are small, simply measuring and correcting for heat from the heater disc that does not flow into the specimen is preferable.

Method and apparatus for measuring thermal conductivity of small, highly insulating specimens

This invention comprises reinforced aerogel monoliths such as silica aerogels having a polymer coating on its outer geometric surface boundary, and to the method of preparing said aerogel monoliths. The polymer coatings on the aerogel monoliths are derived from polymer precursors selected from the group consisting of isocyanates as a precursor, precursors of epoxies, and precursors of polyimides. The coated aerogel monoliths can be modified further by encapsulating the aerogel with the polymer precursor reinforced with fibers such as carbon or glass fibers to obtain mechanically reinforced composite encapsulated aerogel monoliths.

Surface modified aerogel monoliths

A hot plate method and apparatus for the measurement of thermal conductivity combines the following capabilities: 1) measurements of very small specimens; 2) measurements of specimens with thermal conductivity on the same order of that as air; and, 3) the ability to use air as a reference material. Care is taken to ensure that the heat flow through the test specimen is essentially one-dimensional. No attempt is made to use heated guards to minimize the flow of heat from the hot plate to the surroundings. Results indicate that since large correction factors must be applied to account for guard imperfections when specimen dimensions are small, simply measuring and correcting for heat from the heater disc that does not flow into the specimen is preferable. The invention is a hot plate method capable of using air as a standard reference material for the steady-state measurement of the thermal conductivity of very small test samples having thermal conductivity on the order of air.

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Independence, OH, United States of America

Maria A Kuczmarski