Abstract: The present invention relates to a system and method for unidirectional data transmission. Data is unidirectionally transmitted from a network having a higher security level to a network having a lower security level and a corresponding data verification result is received through a separate line. Hence, it is possible not only to physically block access to the network having a higher security level from the network having a lower security level but also to improve reliability of data delivery by appropriately handling packet loss and bit errors that may occur during data transmission.

Abstract: The present invention relates to a system and method for unidirectional data transmission. Data is unidirectionally transmitted from a network having a higher security level to a network having a lower security level and a corresponding data verification result is received through a separate line. Hence, it is possible not only to physically block access to the network having a higher security level from the network having a lower security level but also to improve reliability of data delivery by appropriately handling packet loss and bit errors that may occur during data transmission.

Abstract: A clay-polyurethane nanocomposite comprising a clay and a polyurethane covalently bonded to the surface of the clay wherein the polyurethane is formed by reacting a clay-containing diisocyanate compound with a polyol, the clay-containing diisocyanate compound contains a diisocyanate compound covalently bonded to surface silanol groups of the clay and 0.5˜5% by weight of the clay based on the diisocyanate compound, and the clay is exfoliated by the polyurethane such that no wide-angle X-ray diffraction (WAXD) peak is detected between 2° and 10° by XRD measurement. The clay-polyurethane nanocomposite structure has clay layers are completely exfoliated. In addition, the clay-polyurethane nanocomposite can be foamed to prepare a foamed clay-polyurethane nanocomposite.

Abstract: Disclosed herein is a clay-polyurethane nanocomposite comprising a clay and a polyurethane covalently bonded to the surface of the clay wherein the polyurethane is formed by reacting a clay-containing diisocyanate compound with a polyol, the clay-containing diisocyanate compound contains a diisocyanate compound covalently bonded to surface silanol groups of the clay and 0.5-5% by weight of the clay based on the diisocyanate compound, and the clay is exfoliated by the polyurethane such that no wide-angle X-ray diffraction (WAXD) peak is detected between 2° and 10° by XRD measurement. The clay-polyurethane nanocomposite has a structure wherein the clay layers are completely exfoliated, rather than a structure wherein the polyurethane is intercalated between the clay layers. Accordingly, the clay-polyurethane nanocomposite has superior physical properties to a pure polyurethane.