Abstract: A method for providing frequency selective surface zoning includes selecting a location for positioning a frequency selective surface (FSS) panel along a support arm of a reflector antenna system, and positioning a second feed horn on the support arm on an opposite side of the FSS panel. A number of unit cells are used to populate the FSS panel, and metallic patterns are formed on each unit cell. Multiple zones are subsequently defined on the surface of the FSS panel. Each zone is optimized for a predetermined range of incident angles.

Abstract: A method for providing frequency selective surface zoning includes selecting a location for positioning a frequency selective surface (FSS) panel along a support arm of a reflector antenna system, and positioning a second feed horn on the support arm on an opposite side of the FSS panel. A number of unit cells are used to populate the FSS panel, and metallic patterns are formed on each unit cell. Multiple zones are subsequently defined on the surface of the FSS panel. Each zone is optimized for a predetermined range of incident angles.

Abstract: Molding compositions for shaping parts from stainless steel powders are disclosed. The process comprises the steps of forming a mixture comprising stainless steel powder, a gel-forming material having a gel strength, measured at a temperature between 0° C. and about 30° C. and a gel comprising about 1.5 wt % of the gel-forming material and water, of at least about 200 g/cm2, and water, and molding the mixture at a temperature sufficient to produce a self-supporting article comprising the powder and gel. The preferred gel-forming material is an agaroid and the preferred molding process is injection molding.

Abstract: This invention provides a composition and a process for forming sintered, molded articles having improved dimensional stability. More particularly, this invention pertains to a composition having a sugar additive that increases the solids loading potential of the composition and a process for forming injection molded articles therefrom. Increasing the solids loading potential of the composition, enables the formation of metal or ceramic articles attaining about 98-99% of their theoretical maximum density, without cracking or shrinking significantly during sintering.

Abstract: Recycled, reground ceramic powder is mixed with a liquid carrier, a binder and processing additives to form a material useful for molding complex-shaped parts at relatively low pressures in conventional injection molding equipment.

Abstract: Molding compositions for shaping parts from stainless steel powders are disclosed. The process comprises the steps of forming a mixture comprising stainless steel powder, a gel-forming material having a gel strength, measured at a temperature between 0.degree. C. and about 30.degree. C. and a gel comprising about 1.5 wt % of the gel-forming material and water, of at least about 200 g/cm2, and water, and molding the mixture at a temperature sufficient to produce a self-supporting article comprising the powder and gel. The preferred gel-forming material is an agaroid and the preferred molding process is injection molding.

Abstract: Parts from ceramic and/or metal powder(s) are shaped by a process that comprises the steps of (1) forming a mixture comprising ceramic and/or metal powder(s), a gel-forming material chosen from the class of polysaccharides known as "agaroids", a gel-forming solvent, and a gel strength enhancing agent, and said mixture being formed in a blender that provides a shearing action and being heated to raise the temperature of the mixture to about 70.degree. C. to 100.degree. C.; and (2) molding the mixture at a temperature sufficient to produce a self-supporting structure comprising the powder and gel. The parts exhibit excellent green strength and are rapidly fired without cracking, distortion or shrinkage problems.

Abstract: A nitrogen containing feedstock is hydrodenitrified by passing the feed through at least two hydrodenitrification zones, with ammonia produced in the hydrodenitrification being purged from the system prior to the last hydrodenitrification zone to maintain a low ammonia partial pressure in the last hydrodenitrification zone. The ammonia is preferably purged by stripping ammonia from the liquid portion of the effluent withdrawn from the next to last hydrodenitrification zone. Improved denitrification is obtained by maintaining a low ammonia partial pressure in the last hydrodenitrification zone.