Abstract: Single crystals of (NH4)2Ni(SO4)2.6H2O represent an excellent material for filtering UV light and in an enclosed system will not deteriorate at temperatures as high as 125° C. They are particularly useful in solar-blind optical systems and sensing devices, which seek to identify the presence of UV light sources in the UV missile warning band.

Abstract: A crystal having good optical transmission between 260 nm and 280 nm and strongly absorbing at 285 nm and higher, which is nonhydroscopic and stable at temperatures to 250° C. An example of such a crystal is Cerium doped YLiF4. These properties make YLiF4 crystals doped with Ce3+ excellent materials for use as UV filters in the missile early warning spectral band. Optical devices including missile detection systems are also provided.

Abstract: A laser device which is tunable within the mid-IR range is provided. The device includes a thin etalon, formed as an uncoated plane-parallel plate of high refractive index material, which is transparent for both pump and resonant (signal, idler or both) radiation, for coupling the pump beam to the cavity of an optical parametric oscillator. Such an optical element does not require thin film optical coatings and inherently possesses a high optical damage threshold. Furthermore, high reflectivity at the pump wavelength and high transmittance for oscillating radiations are provided, by orienting the etalon at the Brewster angle. Examples of such materials include silicon and germanium, which are transparent at wavelengths longer than approximately 1 .mu.m and 2 .mu.m, respectively, and have refractive indices of n=3.4 and n=4.0, respectively.

Abstract: Inorganic membranes such as zeolite membranes or other molecular sieve membranes can be provided by using silicone polymer material as starting material. A thin film zeolite membrane or a thin film membrane formed of interlocking zeolite crystals can be provided. Water soluble or water insoluble silicones can be treated in a basic solution under conditions and with an appropriate structure directing template, suitable aluminum content and at a temperature that is appropriate for growing a desired inorganic crystal framework. The membranes can be formed across the perforation of a support, such as a steel screen.

Abstract: Methods for forming membranes of semiconductive material incorporating molecular sieve material therein can involve sol gel techniques and suction techniques. The semiconductors, such as metal oxides, sulfides or carbides have photoactivity and are useful in photocatalytic reactions. An example of such a membrane is titanium oxide including zeolite molecular sieve incorporated therein. The membranes can be used to perform useful chemical reactions such as the mineralization of organic chemicals in the presence of light. For example, many toxic organic chemicals can be converted to useful or benign products by contacting those chemicals with active metal oxide-molecular sieve membranes in accordance with the invention and illuminating the membranes with light of a suitable wavelength.

Abstract: A device and method for measuring the thermal conductivity of a thin film by determining the change in temperature near the surface of the film after a sample including the film is illuminated with a beam of light. This can be accomplished by modulating the beam of light at a selected modulation frequency and measuring the amplitude of the sound waves created in the gas near the surface of the sample as a result of the repetitive heating and cooling of the surface. The amplitude of the sound signal will be directly proportional to the thermal resistivity of the thin film, provided that the modulation frequency is selected within an appropriate range. In a preferred embodiment of the invention, a portion of the thin film is removed from (or not deposited on) the substrate and the entire surface of the substrate, including the portion coated with the thin film and the bare half is coated with a layer of covering material, such as graphite or metal.

Abstract: Inorganic membranes such as zeolite membranes or other molecular sieve membranes can be provided by using siliconee, polymer material as starting material. A thin film zeolite membrane or a thin film membrane formed of interlocking zeolite crystals can be provided. Water soluble or water insoluble silicones can be treated in a basic solution under conditions and with an appropriate structure directing template, suitable aluminum content and at a temperature that is appropriate for growing a desired inorganic crystal framework. Heteroatoms can be included in the crystalline framework.

Abstract: The photoconversion of steroids is carried out in microreactors to yield desired products, while limiting the formation of undesirable byproducts. The steroid reactant is combined with a microreactor such as solid particles having controlled spaces of appropriate size to provide stereochemical control over the reaction. Appropriate catalyst particles include silica and zeolitic material. The reaction can be conducted in a fluidized bed reactor and the formation of undesirable byproducts can be effectively limited.

Abstract: Inorganic membranes such as zeolite membranes or other molecular sieve membranes can be provided by using silicone polymer material as starting material. A thin film zeolite membrane or a thin film membrane formed of interlocking zeolite crystals can be provided. Water soluble or water insoluble silicones can be treated in a basic solution under conditions and with an appropriate structure directing template, suitable aluminum content and at a temperature that is appropriate for growing a desired inorganic crystal framework. The continuous thin film membranes or interlocking crystal membranes can be formed on the sides of a reaction vessel, on the surface of the solution or on the surfaces of substrates introduced into the vessel.

Abstract: Methods for forming membranes of semiconductive material incorporating molecular sieve material therein can involve sol gel techniques and suction techniques. The semiconductors, such as metal oxides, sulfides or carbides have photoactivity and are useful in photocatalytic reactions. An example of such a membrane is titanium oxide including zeolite molecular sieve incorporated therein. The membranes can be used to perform useful chemical reactions such as the mineralization of organic chemicals in the presence of light. For example, many toxic organic chemicals can be converted to useful or benign products by contacting those chemicals with active metal oxide-molecular sieve membranes in accordance with the invention and illuminating the membranes with light of a suitable wavelength.

Abstract: A rotating fluidized bed reactor in which inert solid particles are held in place by centrifugal forces. The reactor includes a rotating porous bed vessel drum within a plenum vessel and the drum rotates to hold the solid particles at the side thereof. Gas is introduced through the walls of the drum and can be drawn off at the top. An electromagnetic radiation source can be included within the drum for promoting photochemical reactions. The solid particles can be inert particles that are loaded with reactant which reacts with the gas stream and/or from the electromagnetic radiation. In other embodiments of the invention, the particles do not contain reactant and reactant is provided within the gas stream only. Such a rotating bed reactor is suitable for use with both batch and continuous flow through processes.