A window assembly heat transfer system is disclosed in which a window member has a selected transparency to monitored or sensed light wavelengths. One or more passages are provided in the window member for flowing a single-phase or two-phase heat transfer fluid, the passages being optically non-transparent to the monitored or sensed light wavelengths. A mechanism allows either evaporation or condensation of the fluid and/or balancing of a flow of the fluid within the passages. In one embodiment, the window assembly can be made by producing passages in a top surface of a first single plate, optionally producing passages in a bottom surface of a second single plate and bonding the top surface of the first plate to a bottom surface of a second single plate to form the window member with the passage or passages. In another embodiment, the window assembly can be made by providing a core around which the window member material is grown and thereafter removing the core to produce the passage or passages.

A window assembly heat transfer system is disclosed in which a window member has a selected transparency to monitored or sensed light wavelengths. One or more passages are provided in the window member for flowing a single-phase or two-phase heat transfer fluid, the passages being optically non-transparent to the monitored or sensed light wavelengths. A mechanism allows either evaporation or condensation of the fluid and/or balancing of a flow of the fluid within the passages. In one embodiment, the window assembly can be made by producing passages in a top surface of a first single plate, optionally producing passages in a bottom surface of a second single plate and bonding the top surface of the first plate to a bottom surface of a second single plate to form the window member with the passage or passages. In another embodiment, the window assembly can be made by providing a core around which the window member material is grown and thereafter removing the core to produce the passage or passages.

A silicon carbide single-crystal substrate having a first main surface angled off relative to a {0001} plane, and a first peripheral edge provided continuously with the first main surface is prepared. A silicon carbide epitaxial layer is formed on the first main surface. The silicon carbide epitaxial layer has a second main surface in contact with the first main surface, a third main surface opposite to the second main surface, and a second peripheral edge provided continuously with each of the second main surface and the third main surface. A peripheral region including the first peripheral edge and the second peripheral edge is removed. The silicon carbide epitaxial layer has a thickness of not less than 50 μm in a direction perpendicular to the third main surface.

A silicon carbide single-crystal substrate having a first main surface angled off relative to a {0001} plane, and a first peripheral edge provided continuously with the first main surface is prepared. A silicon carbide epitaxial layer is formed on the first main surface. The silicon carbide epitaxial layer has a second main surface in contact with the first main surface, a third main surface opposite to the second main surface, and a second peripheral edge provided continuously with each of the second main surface and the third main surface. A peripheral region including the first peripheral edge and the second peripheral edge is removed. The silicon carbide epitaxial layer has a thickness of not less than 50 μm in a direction perpendicular to the third main surface.

A device includes a semiconductor substrate containing gallium nitride and having a crystal face inclined from 0.05° to 15° inclusive with respect to the c-plane. The semiconductor substrate includes an irregular portion on the crystal face, and the contact angle of pure water having a specific resistance of 18 MΩ.Math.cm or more on the surface of the irregular portion is 10° or less.

A device includes a semiconductor substrate containing gallium nitride and having a crystal face inclined from 0.05° to 15° inclusive with respect to the c-plane. The semiconductor substrate includes an irregular portion on the crystal face, and the contact angle of pure water having a specific resistance of 18 MΩ.Math.cm or more on the surface of the irregular portion is 10° or less.

Disclosed is a qualitative evaluation method of a volumetric defect density due to other grains having different crystal orientations from a single crystal matrix in a (001) monoclinic gallium oxide sample or a (010) monoclinic gallium oxide sample.

The method includes the steps of: forming an etch pit by etching an observation plane of a single crystal; and selecting a quadrilateral etch pit formed by volumetric defects except for void defects.

Methods are provided for the manufacture of razor blades from silicon material. In some implementations, the method includes aligning a mono-crystalline silicon wafer comprising a {100} surface at an angle where {111} planes intersect the {100} surface parallel and perpendicular to the wafer; etching the mono-crystalline silicon wafer to expose an {111} plane and a second plane to provide a blade edge having between about a 20 degree included blade angle and about a 35 degree included blade angle; applying a hard coating on the blade edge; providing a radius of curvature of the blade edge between about 20 nanometers and about 100 nanometers after deposition of the hard coating; applying a soft coating on the blade edge; and removing the razor blade from the mono-crystalline silicon wafer.

Methods are provided for the manufacture of razor blades from silicon material. In some implementations, the method includes aligning a mono-crystalline silicon wafer comprising a {100} surface at an angle where {111} planes intersect the {100} surface parallel and perpendicular to the wafer; etching the mono-crystalline silicon wafer to expose an {111} plane and a second plane to provide a blade edge having between about a 20 degree included blade angle and about a 35 degree included blade angle; applying a hard coating on the blade edge; providing a radius of curvature of the blade edge between about 20 nanometers and about 100 nanometers after deposition of the hard coating; applying a soft coating on the blade edge; and removing the razor blade from the mono-crystalline silicon wafer.

An abrasive particle having an irregular surface, wherein the surface roughness of the particle is less than about 0.95. A method for producing modified abrasive particles, including providing a plurality of abrasive particles, providing a reactive coating on said particles, heating said coated particles; and recovering modified abrasive particles.