Abstract: Methods for producing silicon carbide crystals, seed crystal holders and seed crystal for use in producing silicon carbide crystals and silicon carbide crystals are provided. Silicon carbide crystals are produced by forcing nucleation sites of a silicon carbide seed crystal to a predefined pattern and growing silicon carbide utilizing physical vapor transport (PVT) so as to provide selective preferential growth of silicon carbide corresponding to the predefined pattern. Seed holders and seed crystals are provided for such methods. Silicon carbide crystals having regions of higher and lower defect density are also provided.

Abstract: A high-resistivity silicon carbide single crystal is disclosed that includes at least one compensated dopant having an electronic energy level far enough from an edge of the silicon carbide bandgap to avoid conductive behavior, while far enough from mid-gap towards the band edge to create a greater band offset than do mid-level states when the substrate is in contact with a doped silicon carbide epitaxial layer and when the net amount of the dopant present in the crystal is sufficient to pin the Fermi level at the dopant's electronic energy level. The silicon carbide crystal has a resistivity of at least 5000 ohms-centimeters at room temperature.

Abstract: An intake port for an internal-combustion engine is composed of an inlet duct which is constructed in the cylinder head and has a more curved section close to the combustion space and a flat or less curved section away from the combustion space. The inlet duct is adjoined by an intake connection piece which is fastened to the cylinder head and is connected wit the intake system. In the intake port formed of the intake connection piece and the inlet duct, a guiding device is constructed which is arranged in the inlet duct and extends into the more curved area of the inlet duct. The guiding device includes a movable section to differently guide the inlet duct flow as a function of engine operating conditions.

Abstract: A method for cylinder cutout in an internal combustion engine, with the engine having charge exchange valves on a portion of its cylinders. The charge exchange valves can be cut out as well as a switchable fuel supply, both of which can be switched from a cut-out or cut-off state to a cut-in state and vice versa. In order to provide a method for cylinder cutout that permits a safe transition from operation in which they are not cut out to one in which they are cut out, and by which the effects of cylinder cutout on fuel consumption and exhaust behavior are minimized, the fuel supply and the charge exchange valves may be cut out separately or in parallel. Before cylinder cutout, both the time required to cut out the charge exchange valves and the time required to cut off the fuel supply are calculated. Then these two times are compared and a waiting time is determined for the shorter process. When the next reference mark on the internal combustion engine is reached, both processes can proceed independently.

Abstract: A method for cylinder cut-in in an internal combustion engine, with the engine having on a portion of its cylinders. The charge changing valves can be cut out as well as a switchable fuel supply, both of which can be switched from a cut-out or cut-off state to a cut-in state and vice versa. In order to provide a method for cylinder cut-in that permits a safe transition from operation in which they are cut out to one in which they are not cut out, and by which the effects of this switch are exhaust behavior are minimized, the charge changing valves are cut in first and then, after checking to determine whether the charge changing valves have been switched, the fuel supply is cut in to the cylinders that were previously cut out.