The Dow Chemical Company

Other

Charles A Langhoff

John Allen Wheatley

Stephen E Bales

Arne K Knudsen

Walter J Schrenk

Mark Alan Barger

Ravi Ramanathan

Scott H Delzer

Thiodiphenol copolycarbonates and their use as components of

A multilayered reflective body which is thermoformable and capable of being fabricated into films, sheets and a variety of parts while maintaining a uniform reflective appearance is provided. The reflective polymeric body includes at least first and second diverse polymeric materials of a sufficient number of alternating layers of the first and second polymeric materials such that at least 30% of the light incident on the body is reflected. A substantial majority of the individual layers of the body have an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, and adjacent layers of the first and second polymeric materials differ from each other in refractive index by at least about 0.1. The reflective body may be fabricated into sheets, mirrors, noncorroding metallic appearing articles and parts, reflectors, reflective lenses, and the like.

Optically dissimilar composition for polymeric reflective bodies

A sequence of temporally-spaced radiant energy pulses are applied to the front surface of the sample and the heat rise caused by each thermal pulse is measured at the second surface using a suitable thermocouple or infrared sensor. The temperature rise data for each pulse is digitized and stored in a two-state memory device such as a random access memory. The data from each successive pulse is coadded and statistically processed by averaging to derive a set of favored values indicative of the temperature of the sample as a function of time. The favored values data is further processed using a least squares curve fitting algorithm to determine a numerical value indicative of the diffusivity of the sample.

Laser flash thermal conductivity apparatus and method

Ultrafine, high purity B.sub.4 C is produced by BCl.sub.3, CH.sub.4 or C.sub.2 H.sub.4, and H.sub.2, using a CO.sub.2 laser, when a stoichiometric excess of H.sub.2 and about half the stoichiometric amount of CH.sub.4 or C.sub.2 H.sub.4 is employed.

Process for the preparation of submicron-sized boron carbide powders

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Midland, MI, United States of America

Charles A Langhoff