Abstract: A airfoil blade for vertical axis wind turbines is presented. The airfoil blade comprises an internal cavity, an upper blowing slot disposed on the airfoil blade, and a lower blowing slot on the airfoil blade, and further comprises a valve means for variably connecting the outside air to the internal cavity through the blowing slots to selectively produce a variable lift-drag condition of said airfoil blade.

Abstract: A quarter wave coaxial cavity resonator for producing corona discharge plasma from is presented. The quarter wave coaxial cavity resonator has a folded cavity made of opposing concentric cavity members that are nested together to form a continuous cavity ending in a aperture. A center conductor with a tip is positioned in the cavity. The folded cavity advantageously permits the coaxial cavity resonator to resonate at a lower operating frequency than an unfolded quarter wave coaxial cavity resonator of the same length. Embodiments of the quarter wave coaxial cavity resonator use narrower apertures to reduce radiative losses, and include center conductors that are reactive load elements, such as helical coils. When a radio frequency (RF) oscillation is produced in the quarter wave coaxial cavity resonator, corona discharge plasma is formed at the tip of the center conductor. The corona discharge plasma can be used to ignite combustible materials in combustion chambers of combustion engines.

Abstract: An apparatus and method for igniting combustible materials in a combustion chamber of a combustion engine using corona discharge plasma from a quarter wave coaxial cavity resonator. A tapered quarter wave coaxial cavity resonator is adapted to mate with the combustion chamber. The quarter wave coaxial cavity resonator is coupled with an energy shaping means, or waveform generator, that develops the appropriate waveform for triggering radio frequency oscillations in the quarter wave coaxial cavity resonator. A loop coupling is angularly positioned within the quarter wave coaxial cavity resonator to match impedances between the quarter wave coaxial cavity resonator and the energy shaping means, or waveform generator. Radio frequency oscillations produce a standing wave in the quarter wave coaxial cavity resonator and a corona discharge plasma develops near the center conductor.

Abstract: An apparatus and method for igniting combustible materials in a combustion chamber of a combustion engine using corona discharge plasma from a coaxial cavity resonator. This system and method uses a coaxial cavity resonator in a body adapted to mate with a combustion chamber of a combustion engine. The coaxial cavity resonator is coupled with an energy shaping means that develops the appropriate waveform for triggering radio frequency oscillations in the coaxial cavity resonator. A connection means on the apparatus allows for the apparatus to accept an electrical ignition stimulus from an electronic ignition control system. The coaxial cavity resonator develops corona discharge plasma at a discharge electrode when a sustained radio frequency oscillation results in a standing wave in the coaxial cavity resonator. The corona discharge plasma developed near the discharge electrode ignites the combustible materials in the combustion chamber of the combustion engine.

Abstract: An apparatus and method for igniting combustible materials in a combustion chamber of a combustion engine using corona discharge plasma from a coaxial cavity resonator. This system and method uses a coaxial cavity resonator in a body adapted to mate with a combustion chamber of a combustion engine. The coaxial cavity resonator is coupled with an energy shaping means that develops the appropriate waveform for triggering radio frequency oscillations in the coaxial cavity resonator. A connection means on the apparatus allows for the apparatus to accept an electrical ignition stimulus from an electronic ignition control system. The coaxial cavity resonator develops corona discharge plasma at a discharge electrode when a sustained radio frequency oscillation results in a standing wave in the coaxial cavity resonator. The corona discharge plasma developed near the discharge electrode ignites the combustible materials in the combustion chamber of the combustion engine.

Abstract: A method and apparatus for verifying the authenticity of a document relative to a previously programmed document are disclosed. The method provides a broadband light source; illuminates a document with the light source; collects reflected light; converts it into a corresponding electrical signal or signals; digitizes the electrical signals; and prepares a spectral signature of the document for further analysis. The spectral signature can also be normalized to account for variations in analyzed documents caused by soiling and fading. The method also provides for comparing a previously programmed and stored spectral signature to the spectral signature of a test document using a matching value to indicate whether the test document is authentic or not. The apparatus provides a device for application of the method for verifying document authenticity.

Abstract: An electromagnetic antenna includes a multiply connected surface, such as a toroidal surface; first and second insulated conductors; and first and second signal terminals. The first insulated conductor extends around and over the surface with a first pitch or winding sense from a first node to a second node. The second insulated conductor also extends around and over the surface with a second pitch or winding sense, which is opposite from the first pitch or winding sense, from a third node to a fourth node. The first and second insulated conductors are contrawound relative to each other around and over the surface. In one embodiment of the invention, at least one of the nodes is open. In other embodiments of the invention, the signal terminals are structured for connection to a cooperative antenna structure.

Abstract: An electromagnetic antenna includes a multiply connected surface, such as a toroidal surface; a first conductive loop proximate to the toroidal surface; a second conductive loop proximate to the toroidal surface; first and second signal carrying terminals electrically or magnetically connected to the first and second conductive loops, respectively; and a plurality of conductive transceiver elements, such as plural pairs of contrawound insulated conductor windings. Each pair of the contrawound insulated conductor windings has a first end, a plurality of turns, and a second end, and extends around and at least partially about the toroidal surface. Each pair of these windings is electrically connected to the first and second conductive loops. The first end of the windings is electrically connected to one of the first and second conductive loops, and the second end of the windings is electrically connected to the other of the first and second conductive loops.