Abstract: An exemplary heat exchanger, suitable for use in exhaust gas recirculation to cool exhaust gas, includes a cover plate having a plurality of openings, an upper plate having a plurality of openings, a lower plate having a plurality of openings and a bottom plate where seals exist between various plates to form at least one gas flow space and at least one liquid flow space. Various other exemplary heat exchanger configurations are also disclosed.

Abstract: Improved, adaptable tissue-type heart valves and methods for their manufacture are disclosed wherein a dimensionally stable, pre-aligned tissue leaflet subassembly is formed and its peripheral edge clamped between and attached to an upper shaped wireform and a lower support stent. A variety of adaptable structural interfaces including suture rings, flanges, and conduits may be attached to the support stent with or without an outlet conduit disposed about the wireform to provide a tissue-type heart valve adaptable for use in either a natural heart or in mechanical pumping devices. The methods include forming individual leaflets with a template and using the template to attach the leaflets together to form a tissue leaflet subassembly. The template and leaflets include a straight edge terminating in oppositely directed tabs, and a curvilinear cusp edge extending opposite the straight edge.

Abstract: A control system for a variable-geometry turbocharger includes a supervisor logic (12) selecting a pulse control output (24) for large variation of desired and previous control signal inputs exceeding a threshold differential and a normal control signal (26) for small control signal input changes. The control system calculates an amplitude and duration for the pulse control output based on input control signal variation or the actual versus desired position of the variable-geometry system in the turbocharger.

Abstract: An apparatus and method for cooling hot fluids, especially exhaust gases, with a multi-pass cooler core. The cooler core is particularly useful for cooling exhaust gases flowing in an exhaust gas recirculation (EGR) system or regime in operative association with an internal combustion engine, such as a diesel engine. Cooled gases are recirculated to the engine input to help reduce noxious exhaust emissions. The invention utilizes unequal areas-in-flow between the first exhaust pass through the core and the second and subsequent passes through the core. The first pass through the core features an area-in-flow comparatively larger than the area-in-flow of the second pass. The difference in areas-in-flow between passes influences gas velocities to reduce fouling, despite changes in exhaust gas temperature between passes through the core.

Abstract: A high-pressure ratio turbocharger of this invention has a two-stage compressor section comprising a first-stage compressor impeller rotatably disposed in a first compressor housing, and a second-stage compressor impeller rotatably disposed in a second-stage compressor housing. The first and second stage compressor impellers are attached to a common shaft, and are positioned within respective compressor housing in a direction facing away from one another. A portion of the second-stage compressor housing is formed from a compressor backplate attached to a turbocharger center housing. A scroll seal is disposed between the first and second-stage compressor housings, and is interposed between the impellers to separate outlet air flow between each respective first and second-stage compressor chamber.

Abstract: A surgical knife which provides improved multi-sided incisions and is preferably allows for a substantially cruciate, or cross-shaped incision. The surgical knife includes a handle and a multi-bladed portion located at one end of the handle. The handle is sized and configured to maximize grip and surgical manipulation thereof. The multi-bladed portion is formed from a primary blade and a secondary blade. The primary blade is configured with two exemplary primary blade members. The primary blade members are formed with sharpened edges which combined to form a sharpened distal point of the primary blade. The secondary blade is formed with sharpened edges and cooperates with the primary blade. The coupling of the primary blade and the secondary blade is such that the distal end of the secondary blade is located at a distance from the sharpened distal point of the primary blade.