Abstract: A downhole tool configured for inclusion in a drill string, typically as part of a bottom hole assembly. The downhole tool configured to improve passage of the drill string through a borehole. Additionally, the downhole tool is suitable for use in a method for improving passage of a drill string through a borehole.

Abstract: An ultraviolet and infrared reflecting coating with a wide transmission band and a solar cell cover on which the coating has been deposited. The coating contains a multilayer bandpass filter, and some of the layers of this filter are comprised of mixed materials which have a selectable index of refraction. The design can be optimized by varying the index or refraction of at least one of the layers of mixed material.

Abstract: An optical thin film filter for the spatial and spectral separation of two or more transmitting bands of radiant energy. For a two band filter the filter has a substrate substantially transparent to radiant energy in the transmitted bands. On one surface of said substrate is a multilayer interference coating that transmits both wavelength bands of interest. On the other surface of said substrate (or on the same surface) are two sets of non-overlapping butted, parallel stripes with one set being alternately interspersed with the other. The widths of said stripes are varied to provide for precisely defined regions of spatial and spectral delineation. One set of stripes is capable of transmitting one of the bands of interest and reflecting all others, while the second set of stripes is capable of transmitting at least one band different from the one band transmitted by said first set of stripes and reflecting all others.

Abstract: An optical thin film filter for the spatial and spectral separation of two or more transmitting bands of radiant energy. For a two band filter the filter has a substrate substantially transparent to radiant energy in the transmitted bands. On one surface of said substrate is a multilayer interference coating that transmits both wavelength bands of interest. On the other surface of said substrate (or on the same surface) are two sets of non-overlapping butted, parallel stripes with one set being alternately interspersed with the other. The widths of said stripes are varied to provide for precisely defined regions of spatial and spectral delineation. One set of stripes is capable of transmitting one of the bands of interest and reflecting all others, while the second set of stripes is capable of transmitting at least one band different from the one band transmitted by said first set of stripes and reflecting all others.

Abstract: In vapor deposition apparatus, a plurality of spaced substrates on a rotatable horizontally disposed support, a vapor source disposed below said support and offset with respect to the axis of rotation of the support, and a mask extending approximately 180.degree. which is uniformly disposed and diametrically opposed with respect to said source whereby the effective vapor stream is generally normal to exposed substrates. A continuously exposed monitor chip is provided.