Abstract: The invention relates to a method for ventilating and temperature controlling rooms according to the principle of dilution ventilation, wherein a primary air flow (40) is introduced into the ceiling cavity (30) of a room (4), which is partitioned from a story ceiling (26) by a false ceiling (31) and is introduced into the room (4) by means of porosities (41, 42, 43) in the false ceiling (31), wherein the primary air flow (40) in the ceiling cavity (30) produces a secondary air flow (33) as an induction air flow, which vacuums a room air flow (32) from the room (4) into the ceiling cavity (30), mixes with the secondary air flow (33) and introduces it into the room (4) as a tertiary air flow (34) through the porosities (41, 42, 43) in the false ceiling (31).

Abstract: In order to achieve a high cooling power while avoiding troublesome cold air flows, a chamber (2) is sealed, from the room to be cooled, by a thin cooling wall (1) of powder-coated steel with micro-holes which are arranged in a square 5 mm grid and have a diameter of 0.5 mm and whose free cross-section is consequently less than 1%. An antechamber (4) which is connected to the chamber (2) through a partition (3) by means of a distributor nozzle (17) and has air connections for connection to an air supply or an adjacent air-cooling element is arranged above the chamber (2). The cool air is introduced into the chamber (2) via the distributor nozzle (17) in such a way that it passes with high turbulence along the inside of the cooling wall (1). An air-cooling arrangement consists of rows, arranged side by side, of air-cooling elements whose antechambers (4) are connected by connecting nipples which each project into connecting orifices (10) of adjacent air-cooling elements.

Abstract: In order to cool a room, a cooling element fitted in the ceiling region is cooled to below the freezing point, preferably to about −40° C., during the cooling phases so that condensate forming thereon freezes immediately. During regeneration phases when the room is not in use, the cooling element is defrosted and the melted condensate is caught in a condensate tray beneath the cooling element and drained via a discharge. The great temperature difference between the room to be cooled and the cooling element also makes it possible to obtain a strong cooling effect with a small cooling element, especially by indirect radiation exchange between the room and the cooling element via an intermediate ceiling. The air in the room is also dehumidified since water vapor is deposited on and bonded to the cooling element in the form of ice.

Abstract: In order to cool a room, a cooling element fitted in the ceiling region is cooled to below the freezing point, preferably to about -40.degree. C., during the cooling phases so that condensate forming thereon freezes immediately. During regeneration phases when the room is not in use, the cooling element is defrosted and the melted condensate is caught in a condensate tray beneath the cooling element and drained via a discharge. The great temperature difference between the room to be cooled and the cooling element also makes it possible to obtain a strong cooling effect with a small cooling element, especially by indirect radiation exchange between the room and the cooling element via an intermediate ceiling. In addition, the air in the room is dehumidified since water vapour is deposited on and bonded to the cooling element in the form of ice.

Abstract: In order to cool a room, a cooling element fitted in the ceiling region is cooled to below the freezing point, preferably to about -40.degree. C., during the cooling phases so that condensate forming thereon freezes immediately. During regeneration phases when the room is not in use, the cooling element is defrosted and the melted condensate is caught in a condensate tray beneath the cooling element and drained via a discharge. The great temperature difference between the room to be cooled and the cooling element also makes it possible to obtain a strong cooling effect with a small cooling element, especially by indirect radiation exchange between the room and the cooling element via an intermediate ceiling. In addition, the air in the room is dehumidified since water vapor is deposited on and bonded to the cooling element in the form of ice.

Abstract: Process for producing a sound recording cutting base, which includes precipitating a cuttable copper layer on a substrate from an electroplating bath, the copper layer having an initial grain size and having recrystallizing characteristics as a result of the bath's composition, convection and current density, characterized in that in order to extend recrystallization time, substances are added to the bath which, by their incorporation in the copper layer, stabilize the latter in such a manner that recrystallization is prevented or delayed, the substances including leveling agents added in effective amounts to prevent formation of layer-grain crystals of copper having a grain size which substantially exceeds the initial grain-size.

Abstract: Process for manufacturing a record carrier having a cuttable copper layer, wherein a copper layer is precipitated onto a substrate in an electrochemical bath and a desired Vickers hardness in the precipitated copper layer is obtained by controlling the concentration of brightener additives. The copper layer is precipitated in a recrystallizable phase, and the recording is cut while the copper layer is in its recrystallizable phase.

Abstract: In an apparatus for forming a groove which is modulated to present an information track in a signal record carrier having a copper surface portion by cutting such groove into the copper surface portion by means of a cutting stylus, the stylus is formed to present, during cutting, a rake angle of between 10.degree. and 20.degree., and the copper constituting the surface portion into which the groove is cut has a Vickers hardness of between 110 and 300, and preferably between 120-220.

Abstract: A process for producing and operating an electroplating bath in which there appears NH.sub.4.sup.+ ions which impair the quality of the bath comprising adding salts of a hexanitrocobaltate-III complex to the bath to bring about precipitation of the NH.sub.4.sup.+ ions.

Abstract: A matrix, which is to be employed for pressing foil disc copies carrying a spiral groove which is highly concentric to the axis of disc rotation, is formed by electrodeposition from a lacquer foil original which is cut to form a groove corresponding to such spiral groove and to form additional grooves deeper than the spiral groove and having a form that produces, on the matrix, sharp edges capable of directly cutting the outer periphery and center hole of a foil disc copy.