Abstract: A planar transformer including first and second parts of a core with least one of the first and second parts having a center post that resides in an aperture of a PWB. The PWB includes primary windings and secondary windings that surround the center post, are magnetically coupled by the core, and are electrically independent. Separating an uppermost winding from the first part of the core is a first prepreg structure and separating a lowermost winding from the second part of the core is a second prepreg structure. There being no windings disposed between the first and second prepreg structures and the core. This planar transformer structure inhibits the windings from electrically shorting through the core when the planar transformer is subjected to shock or vibration. One variant includes the use of pre-form adhesives sheets located between the solder mask layers of the PWB and the core that further inhibit the windings from shorting through the core.

Abstract: A process for producing nitric acid by the Ostwald process involves reacting ammonia with atmospheric oxygen as primary air to afford a NOx-containing gas stream in an ammonia oxidation reactor at a first pressure and absorbing the NOx-containing gas stream in water in an absorption apparatus at a higher, second pressure. Nitric acid is bleached with bleach air as secondary air at approximately the first pressure. The secondary air is brought to an operating pressure of the bleaching operation via a separate secondary air compressor or compressor stage. The separate secondary air compressor is independent of the compressor that brings the primary air to the first pressure. Compression to the second higher pressure at which the absorption of the NOx gases is performed in the absorption apparatus is provided only downstream of the bleaching operation.

Abstract: A process and a plant for producing nitric acid involves oxidizing ammonia in the presence of catalysts to provide nitrogen monoxide-containing process gas in an oxidation reactor. The formed nitrogen monoxide may be supplied with oxygen-containing gas, and nitrogen monoxide is oxidized to provide nitrogen dioxide that is reacted with water in an absorption apparatus to give nitric acid, nitrous acid, and/or solutions of nitrates and/or nitrites. Oxidation of the nitrogen monoxide may be effected in an additional reactor positioned between the oxidation reactor and the absorption apparatus and traversed by the process gas. The oxidation of the nitrogen monoxide may be effected in an additional reactor parallel and connected to the absorption apparatus and traversed by the process gas. The disclosed processes and plants feature a high energy efficiency combined with a simple construction, and existing plants are easily upgradeable.

Abstract: A process and a plant for producing nitric acid involves oxidizing ammonia in the presence of catalysts to provide nitrogen monoxide-containing process gas in an oxidation reactor. The formed nitrogen monoxide may be supplied with oxygen-containing gas, and nitrogen monoxide is oxidized to provide nitrogen dioxide that is reacted with water in an absorption apparatus to give nitric acid, nitrous acid, and/or solutions of nitrates and/or nitrites. Oxidation of the nitrogen monoxide may be effected in an additional reactor positioned between the oxidation reactor and the absorption apparatus and traversed by the process gas. The oxidation of the nitrogen monoxide may be effected in an additional reactor parallel and connected to the absorption apparatus and traversed by the process gas. The disclosed processes and plants feature a high energy efficiency combined with a simple construction, and existing plants are easily upgradeable.

Abstract: A process and a plant for decreasing the concentration of NOx nitrogen oxides in the residual gas in the preparation of nitric acid, where the temperature of the residual gas is regulated by means of a temperature regulating apparatus during shutdown and/or start-up of the plant, with the residual gas being conveyed in a circuit and here flowing through the temperature regulating apparatus and the residual gas purification plant so that colorless shutdown and/or start-up of the plant is made possible.

Abstract: Solid inorganic particulate salts having increased hardness are produced by incorporating a novel additive composition comprised of ammonium sulfate and a naphthalene sulfonate compound.

Abstract: Fine epitaxial patterns of yttrium barium copper oxide on a strontium titanate substrate are provided by using a silicon nitride mask to define the pattern to be formed. A thin film of yttrium barium copper oxide is placed on the silicon nitride mask and exposed portions of strontium titanate substrate. Where the yttrium barium copper oxide is in contact with the silicon nitride mask, it is nonepitaxial in crystal structure. Where the yttrium barium copper oxide contacts the strontium titanate substrate in the openings, it is epitaxial in structure forming fine patterns that become superconducting below the critical transition temperature. A channel can be formed in the strontium titanate substrate. The epitaxial yttrium barium copper oxide pattern is formed in this channel to minimize possible exposure to the silicon nitride mask.