Abstract: Method and apparatus for the fast inspection of objects for the detection of elementary or compounded metals of the kind that are capable of producing with impinging X-radiation within the range of 60-160 KeV a detectable photoelectric interaction. A 110-160 KeV X-ray source is used in association with collimating and filtering apparatus, capable of generating a collimated X-ray beam consisting of repeating cycles comprising each one energy bin having a flux centred around the K-edge energy of the target metal and, if desired, comprising additionl energy bins. There is also provided a linear array of solid state, spectroscopy grade detectors.

Abstract: A laser application system comprises an amplifier and two rotating polarization devices so that a laser beam is given with linear polarization which is converted into a circular polarization. Then the beam passing through amplifier means, is reflected into a second pass and reflected back to the amplifier. The system further includes a stimulated Brillouin scattering non-linear isolator for transmitting substantially all of the light beam when its energy is below a predetermined threshold and reflecting substantially all of the light beam without substantially reducing the quality of the beam, when its energy exceeds the threshold.

Abstract: A gun for accelerating projectiles in which the travelling chemical charges are ignited by electrothermal energy sources. By one mode there are provided electrothermal energy injectors along the gun barrel which are fired synchronously with the displacement of the projectile within the barrel, each such injector igniting a distinct chemical propellant charge attached to the projectile. Essentially that mode of the gun operates by the travelling charge principle in which the boosting of the thrust on the projectile is brought about by successively ignited propellant charges attached to the projectile itself while the electrothermal energy injectors on the barrel serve for ignition only.By an alternative mode a plasma injector unit is mounted at the rear of the gun coaxially with the barrel and the injected plasma acts via fluid to initiate the chemical propellant and enhances the chemical propellant burning rate to improve the gun performance.

Abstract: A thermoelectric device of the kind that comprises an array of thermoelectric rods of two different materials alternatingly arranged between two carrier plates with each carier plate being a plurality of discrete conductive metal junctions to which the thermoelectric rods are pairwise connected. The two carrier plates are made of synthetic polymeric materials and each of the junctions comprises a monolithic metal member directly linked to a carrier plate.

Abstract: A method for the detection of a nitrogenous explosive material in an object is provided which makes use of nuclear resonance absorption. The object to be tested is placed between a 9.17 MeV .gamma.-rays source and an .gamma.-rays detector holding a nitrogen medium. The total and the non-resonant attenuation of the .gamma.-rays flux is read by the detector and fed into a recorder. From the measured attenuation the net non-resonant attenuation is calculated and the amount of a nitrogenous explosive present in the object is determined therefrom.Also provided by the invention is a system for detecting a nitrogenous explosive in an object.

Abstract: Optical glass elements with graded refraction index in the infra red region. The elements are made of doped oxygen free chalcogenide glass. The concentration of the dopant decreases from the periphery inward. Typical examples of dopants are As, S and Se.The glass elements are prepared by exposing an oxygen free chalcogenide glass to a molten chemical element or salt at about 150.degree.-400.degree. C. in an oxygen free atmosphere.