Abstract: In order to scrub a waste gas, for example, of foreign matter by means of an electrostatic filter, a power supply is provided which contains a converter whose output feeds the primary winding of a high-voltage transformer. The secondary winding is connected to the electrostatic filter via a high-voltage rectifier. Disposed in the intermediate circuit of the converter is a control element for the intermediate circuit current. This shields the supply network against the effects of the power converter commutations and of short-circuits in the filter to a great extent. A limiter for the filter voltage and a temporary separation of the transformer from the inverter in case of filter short-circuits may be provided to reduce the stress on the components which can be made small if a high-frequency working cycle for the setter and the inverter is used.

Abstract: A container body is formed of a polymer material and contains coloring matter effective to render the body substantially opaque to electromagnetic radiation having a wave length of about 5 to about 600 nm and translucent or semi-transparent to electromagnetic radiation having a wave length of about 600 to about 800 nm. The container permits storage and transport of photosensitive fluids, for example, body fluids for test purposes which contain bilirubin and other photo-degradable substances, but at the same time the contents of the container body are apparent from visual inspection.

Abstract: An electrostatic precipitator is fed high voltage pulses by a pulse generating circuit including a high voltage transformer and a first thyristor switch connected in series with a primary winding of the transformer. Magnetic saturation of the core of the high voltage transformer is prevented by recurrently short circuiting the primary winding of the transformer by means of a second thyristor switch connected in parallel to the primary winding. The second thyristor switch is closed for a period of time extending from a first instant following a high voltage pulse crest to a second instant at or before the start of a pulse generating cycle subsequent to the pulse crest.

Abstract: A method for detecting breakdowns in an electrostatic filter in which single measured values of equal phase of successive half waves of the filter voltage and crest values of successive half waves of the primary current are compared with one another and in which the differences of the measured values at which a breakdown signal is delivered are made dependent on the existing filter voltage or the primary current.

Abstract: The optimum knock frequency of an electrofilter installation consisting of several filters is determined. Each filter includes a microcomputer controller and a knocking device. The knock frequency is controlled by a superimposed master computer and the optimum knock frequency for a given knock frequency, varying the frequency by the master computer, again measuring the long-term average of the dust loading, and continuing to change the frequency and measure the dust loading until the dust loading value reaches a minimum.

Abstract: A system for controlling the voltage of an electrofilter of the type which, after a voltage breakdown, substantially reduces the magnitude of the electrofilter voltage. After a predetermined deionization time, the filter voltage is raised to a new level which is lower than the filter voltage at which the initial voltage breakdown occurred, by a predetermined amount. The filter voltage is subsequently raised in accordance with a predetermined voltage-time function until a further voltage breakdown occurs. The electrofilter voltage is controlled by a microcomputer system in accordance with stored control parameter values. The stored control parameter values are advantageously recalled to control the electrofilter voltage in response to the operating state of a plant in which the electrofilter is employed.

Abstract: A liquid crystal display and a method of fabricating the same are disclosed, comprising two substantially plane parallel transparent substrates or carriers, two polarizer foils applied to the outer faces or sides of the substrates and a liquid crystal material enclosed between the substrates. The liquid crystal display is encapsulated with a layer formed of poly-para-xylylene, 2-chloro-poly-para-xylylene or 2,2'-dichlor-poly-para-xylylene. The encapsulation is produced in accordance with the parylene method at a deposition rate .gtoreq. 10 .ANG./sec.

Abstract: A method for operating an electrostatic precipitator with a DC voltage and superimposed pulses or superimposed AC voltage in which individual parameters such as amplitudes, pulse repetition frequency, pulse width, etc. are iteratively and continuously varied in such a manner that the sum of the pulse and the DC voltage power approaches a minimum. A computer which calculates, from the dust load and the absorbed electric energies of the filter, control commands for the DC and pulse voltage source is used for this purpose.

Abstract: A cutter and mixer apparatus for foodstuffs has a bowl 4 rotatably mounted in a housing. Rotary knives 10 are attached to a shaft 16 and extend into the bowl. The bowl is covered by two hoods 31, 32 which are hinged approximately in the middle above the bowl and can be swung up and open opposite one another. Below the bowl a primary plate 3 is situated on whose one end a vertical sidewall 20 is welded. An angled yoke 24 spans the bowl and is attached at one end to the sidewall and at the other end to the opposite side of the primary plate. The plate, sidewall and yoke form the support frame for the apparatus on which all important functional parts are attached. The closed construction provides for an efficient power transfer and a high level of stability.

Abstract: A system for automatically controlling the voltage of an electrostatic filter with respect to its breakdown voltage limit. The detection of secondary voltage breakdowns which occur within a post-breakdown time period after an initial voltage breakdown cause the filter voltage to be lowered to zero value. After a deionizing time period, the filter voltage is gradually raised during a predetermined rise time period until it reaches a new value. The duration of the deionizing time period and the rise time period may be advantageously computed in response to the history of voltage breakdowns, by a microcomputer system.

Abstract: The automatic recording of the current-voltage characteristic of an electrostatic filter in which the characteristic obtained upon stepwise variation of the control is displayed to the operating personnel and at the same time saturation phenomena and voltage maxima are picked up.

Abstract: A method for controlling the voltage of an electrostatic filter at the breakdown limit in which, when a breakdown occurs, the voltage is reduced by an amount which is determined by the breakdown voltage and the prior history of the breakdown and the waiting time to the next increase of the filter voltage is made dependent on the ratio of the voltages at successive breakdowns by comparing voltage amplitudes which immediately precede the breakdowns.

Abstract: An optically transparent and electrically conductive film pattern on a substrate, e.g., an electrooptical display plate provided with a patterned transparent electrode layer, is prepared by a process in which an optically transparent layer of electrically conductive material, coated on the substrate, is removed in predetermined areas by an etching treatment. In this process, the areas of the optically transparent layer on the substrate which are to be removed by etching are printed with an etchant composition which contains an etching agent for the electrically conductive material. The composition is then allowed to remain in contact with the electrically conductive material in order to etch through the areas covered by the composition. Finally, the products formed by reaction of the etchant products formed by reaction of the etchant with the conductive material are removed together with the unspent portions of the composition.

Abstract: A display element formed by two parallel glass plates each having opposed electrodes provided thereon and an optical medium disposed in the intermediate space therebetween, wherein a connection between at least one electrode of one plate and at least one electrode of another plate, and the interplate spacing is achieved by means of electrically conducting fibers each having the same constant diameter disposed between the plates around the periphery thereof, with the conductive fibers contacting the respective electrodes formed on the display plates and thereby electrically connecting the same. The spacing for the display element is derived by mixing the conductive fibers in an adhesive compound to form a cement ridge around the periphery of the plates and applying the compound containing the conductive fibers to at least one of the plates, and then pressing the plates together until the plates are separated by a distance corresponding to the diameter of the conductive fibers.

Abstract: A particularly active Raney nickel catalyst is provided with a high-iron content, containing about 10 to 30% by weight of iron relative to the sum of the active metals nickel and iron. The catalyst can be prepared by treating aluminum/nickel/iron alloys which contain (1) 21 to 49.5% by weight of nickel, (2) 3 to 16.5% by weight of iron and (3) aluminum to make up to 100%, with an inorganic or organic base and separating the catalyst from the reaction mixture. According to the invention, said particularly active Raney nickel catalysts are used for the hydrogenation of organic compounds.

Abstract: Iridium from the crucible wall, taken into solution during the growth of crystals by the Czochralski technique, is trapped at the bottom of the iridium crucible by cooling at least the bottom of the crucible. This part of the crucible is cooled to a temperature above the solidification temperature of the melt and results in almost inclusion-free crystals.

Abstract: An improved power supply for an electric precipitator which includes a d-c voltage source and a pulsed a-c voltage source coupled to the high-voltage electrodes of the precipitator. The improvement of the invention comprises the pulsed a-c voltage source comprising a high-voltage transformer including a primary winding and a secondary winding, the latter of which is coupled to the high-voltage electrodes of the precipitator. A d-c voltage source has one of the voltage terminals thereof coupled by means of a center tap to the primary winding of the transformer and the other of its voltage terminals coupled to a pair of thyristors and a pair of diodes connected to the ends of the primary winding of the transformer. The thyristors are coupled in anti-parallel relationship with the diodes and are adapted to be triggered in alternating fashion at the frequency of the voltage pulses desired to be generated.

Abstract: Polished single crystal wafers are checked for defects by means of a method employing a optical microscope. The image is blurred by a translucent material and the transmitted light is then sensed by a light sensitive instrument which records the increased light intensity caused by a defect passing through the field of view. The position of the defects are then plotted automatically.

Abstract: A wheel for pneumatic tires for use on motor vehicles having a ring-shaped rim around a central disc or dish wherein the rim is made of a composite section with a light metal body section and an insert of higher strength metal which forms part of the surface of the body section.