Abstract: The present invention provides an improved syntactic foam plug for plug assist thermoforming wherein such plug is composed of a thermoplastic material having a relatively high melting and/or glass transition temperature. Accordingly, the subject invention encompasses diminishing or removing the undesirable characteristics of thermoset syntactic plugs while increasing the ease by which these articles may be constructed for a given use, by forming such plugs from syntactic foams containing thermoplastics.

Abstract: The present invention provides an improved syntactic foam plug for plug assist thermoforming wherein such plug is composed of a thermoplastic material having a relatively high melting and/or glass transition temperature. Accordingly, the subject invention encompasses diminishing or removing the undesirable characteristics of thermoset syntactic plugs while increasing the ease by which these articles may be constructed for a given use, by forming such plugs from syntactic foams containing thermoplastics.

Abstract: The present invention provides an improved syntactic foam plug for plug assist thermoforming wherein such plug is composed of a thermoplastic material having a relatively high melting and/or glass transition temperature. Accordingly, the subject invention encompasses diminishing or removing the undesirable characteristics of thermoset syntactic plugs while increasing the ease by which these articles may be constructed for a given use, by forming such plugs from syntactic foams containing thermoplastics.

Abstract: A warship is provided with a plurality of interior volumes defined by an inner wall structure and an outer wall structure spaced apart from the inner wall structure. The space between the inner wall structure and the outer wall structure includes a syntactic foam-macrosphere composition between the wall structure which dissipates force applied to an outer wall structure.

Abstract: An electromagnetic energy absorber provides a base having an electrically conductive ground plane positioned thereover. At least one dielectric and one impedance layer are positioned over the ground plane or surface on a side thereof opposite the base. An external most dielectric skin seals the structure. Additional alternating dielectric and impedance layers can be positioned over the first dielectric and impedance layers. The impedance layer, can be formed from a resistive sheet formed into a broken pattern that can comprise a series of geometric shapes spaced from each other. The broken pattern is sized to vary the specific impedance of the sheet. The resistive sheet can be combined with a series of composite dielectric layers to form an integral composite structure. Three resistive sheet layers can be provided with predetermined spacings from the ground surface and predetermined impedance to effect broadband absorption characteristics.

Abstract: An electromagnetic energy absorbing structure provides a base structure having an electrically conductive ground plane positioned thereover. At least one dielectric and one impedance layer are positioned over the ground plane or surface on a side thereof opposite the base. An external most dielectric skin seals the structure. Additional alternating dielectric and impedance layers can be positioned over the first dielectric and impedance layers. The dielectric layer can be constructed from syntactic foam with impedance layers formed from patterns of conductive dipoles. The impedance layer, can alternatively, be formed from a resistive sheet formed into a broken pattern that may comprise a series of geometric shapes spaced from each other. The resistive sheet can be combined with a series of composite dielectric layers to form an integral composite structure.

Abstract: Small hollow glass spheres are prepared by adding a surfactant to a liquid glass precursor mixture. The surfactant-containing solution or dispersion can be formed into droplets which are directed into a heated zone and the product collected in a cooler zone. Alternately, the solution or dispersion may be spray-dried, and the spray-dried product is fed into the heated zone and collected in the cooler zone. Nonionic fluorocarbon surfactants are the preferred surfactants.