Abstract: A solar radiation collector is provided. The collector is configured to receive solar radiation from a range of angles including a first range constituting an acceptance angle, and a second range constituting angles outside said first range. It further includes a photovoltaic cell and a regulator, which is configured to regulate the appearance of the collector to an observer within the second range, constituting a source of visible radiation which is visible to an observer within the second range.

Abstract: A solar radiation collector comprising a concentrator and a photovoltaic cell, the concentrator comprising at least a prismatic primary portion, the primary portion comprising primary entrance aperture having a perimeter, an outer surface adapted for receiving radiation, and a inner surface; a primary receiver plane; sidewalls, meeting the primary entrance aperture along at least a portion of the perimeter; and a reflective bottom surface. The primary portion is adapted to utilize total internal reflection at least from the inner surface of the primary entrance aperture to concentrate radiation entering through the primary entrance aperture toward the primary receiver plane.

Abstract: A system, a device and a method for accelerating packet filtration by supplementing a firewall with a pre-filtering module. The pre-filtering module performs a limited set of actions with regard to the packets, according to whether the packets are received from a connection which has been previously permitted by the firewall. If the packets are received from such a permitted connection, then the pre-filtering module forwards the packets to their destination, optionally performing one or more actions on the packets. Otherwise, the packets are forwarded to the firewall for handling. Preferably, once the firewall has transferred responsibility for the connection to the pre-filtering module, or “off-loaded” the connection, the firewall does not receive further packets from this connection until a timeout occurs for the connection, or a packet is received with particular session-control field values, such that the connection is closed.