Abstract: Prawns and like shellfish are shelled by holding them at the tail end, cutting the shell at a point between head and tail, drawing off the head which is discarded, and then drawing the flesh out of the tail part of the shell which is still clamped. Apparatus for performing the shelling comprises a prawn holder which moves sequentially past devices for clamping, cutting and applying suction to the prawns.

Abstract: In a process for melting aluminum or its alloys in an induction melting furnace of the channel type, in which the melting channels are to be protected by cryolithe against the attack of the melt, and wherein a gas or gas mixture is introduced into the melting channels of the inductor units, which gas contains halogens or compounds capable of splitting off halogens, the improvement that, for the production of the necessary quantity of cryolithe the melting charge contains an amount of sodium of at least 15 ppm together with an amount of lithium and/or calcium and/or potassium totalling at least 15 ppm. Substances are also introduced capable of splitting-off fluorine.

Abstract: Stabilized perchloroethylene containing 0.001 to 0.1% by weight of N-alkylmorpholine, 0.001 to 0.01% by weight of alkylphenols, 0.0005 to 0.002% by weight of diisopropylamine, and 0.05 to 0.5% by weight of cyclohexeneoxide. By stabilization with the mixture of stabilizers, the perchloroethylene is stabilized to an extraordinary degree against attack by metals, particularly, decomposition through oxidation in contact with metals or metal salts, in some cases also upon exposure to light. A further improvement of the combined stabilizing action can be obtained by the addition of 0.005 to 0.1% by weight of epoxipropanol.

Abstract: An apparatus for deburring workpieces such as profiles, tubes, metal sheets or the like, is provided which includes a housing and a deburring tool rotatably mounted within the housing about a horizontal axis such that the tool partially projects from the housing. A workpiece holder is located in front of the housing for holding the workpiece to be deburred level with and in abutment with the rotatable tool. The holder has a block portion, which is a workpiece retaining device. The block portion and the workpiece receiving device are displaceable into the housing in a direction towards the tool.

Abstract: A method and device for sintering materials and, in particular, limestone gravel, of very different granular size in the granular range of 5 to 50 mm, in a rotary shaft kiln with a shaft preheater and shaft cooler, are provided wherein the sintering charge of the original gravels are crushed into two or more granular fractions and are fed in a low band width to the furnace system periodically and alternately, and wherein the process gases flow through the filling or charge layers of the sintering materials. The filling layers are automatically changed in the shaft preheater and the shaft cooler in their thickness, so that the flow through resistance thereof remains constant.

Abstract: A firearm is provided which includes a stock having a barrel end face, a generally longitudinally-extending primary bore formed therein and opening onto the barrel end face, and at least one generally transversely-extending, internally-threaded ancillary bore formed therein one end of which opens onto the primary bore and the other end of which opens onto a lateral face of the stock. The firearm also includes a double barrel having a barrel end plate and a bolt secured to the barrel end plate having an annular groove which bolt is demountably and rotatably received within the primary bore with the groove thereof being positioned such that it opposes the ancillary bore. At least one set screw is threadably receivable in the ancillary bore and has an inner end which is configured and dimensioned to permit mating engagement thereof with the annular groove, so as to retain the bolt in the primary bore while permitting rotation thereof and, in turn, the double barrel.

Abstract: A disposable animal litter collector comprising a shovel-type scoop having a flat supporting surface with a leading edge defining the opening of the scoop, vertical sidewalls on each side of the support surface, and a back wall joining the vertical sidewalls. There is a flexible bag having an opening at one end and closed at its opposite end, and joined to the back end of the scoop. A scraper is also provided so that the litter can be pushed onto the scoop and the bag pulled over the entire scoop and sealed for disposal.

Abstract: A board game apparatus is provided which is especially intended for children and which serves as an instructional aid to promote their awareness of the environment and the problems of environmental pollution. The apparatus includes a game board having a playing field and a multiplicity of spaces formed on the playing field which cooperatively define a continuous closed path along which tokens representing players are moveable in random increments. The multiplicity of spaces includes a first group of spaces having designations thereon indicative of an area of environmental concern, a second group of spaces having monetary penalties specified thereon for harms committed to the environment, and a third and fourth group of spaces having instructions thereon for selecting a card from a specified stack of cards having indicia thereon representative of a benefit or penalty assessed to the player who picks the card.

Abstract: A process for producing high purity semiconductor materials and metals by ermal decomposition of a gaseous compound of said materials, comprising the steps of arranging conductive carrier bodies in electrical current branches in a multi-phase a.c. system, then passing an equal amount of electrical current through each of the branches so as to heat the carrier bodies to deposition temperature, regulating the current in each of the branches so that the same magnitude of current flows through each branch.

Abstract: A process for the production of substituted furans of the general formula ##STR1## wherein R is a member of the group consisting of alkoxy radicals having from 1-6 C-atoms, a substituted aryloxy radical, an unsubstituted aryloxy radical and an alkyl radical, R.sub.1 is a alkyl or aryl radical with 1-6 C-atoms, preferably methyl, R.sub.2 and/or R.sub.3 is an alkyl radical with 1-6 C-atoms or hydrogen by reacting a .beta.-dicarbonyl compound with an .alpha.-chlorocarbonyl compound in the presence of a compound capable of combining with the hydrochloric acid formed, at temperatures between 30.degree. and 100.degree. C., the reaction being carried out at pH values between 2 and 7, preferably between 3.5 and 6, with the addition of equimolar amounts of an alkaline earth carbonate.

Abstract: A heating device for heating a glass surface, such as the rear window of a car, includes a pair of elongated electrically non-conductive carrier strips having an adhesive layer on both sides thereof and secured in spaced-apart relationship to the glass surface by one of their adhesive layers to laterally delimit the surface area of the glass encompassed by the heating device. A plurality of spaced, thin electrically conductive foil strips, each cut in predetermined lengths from a continuous strip, and each of which has an adhesive layer on one side, extend between the carrier strips. The ends of the foil strips overlie the carrier strips and are secured to the carrier strips and the glass surface by the adhesive layer thereof. A strip-shaped electrical terminal conductor overlies each carrier strip in electrically conductive engagement with the foil strip ends and is fastened to the carrier strip by the other adhesive layer on the carrier strip exposed between the foil strip ends.

Abstract: An improved shoulder rest for an instrument and, in particular, a violin, viola, or the like, having a chin rest and a supporting clamp engaging a back portion of the instrument generally opposite the chin rest, is provided which includes a mounting base securable between the supporting clamp and the back portion of the instrument. An arm is detachably securable to the base at a number of different locations. A shoulder rest element which rests against the user's shoulder is, in turn, secured to the arm in such a manner so as to permit sliding, rotational, and tilting adjustable movement of the rest element relative to the arm. Thereafter, the shoulder rest element may be locked in the desired and stationary position of orientation relative to the arm.

Abstract: The invention provides a process and an apparatus for machining silicon r and tubes by abrasion. The risk of fracture of such workpieces during grinding is prevented in this method and apparatus by the workpiece being held vertically in a cylindrical grinding machine in which the individual tools are uniformly arranged around the circumference of the workpiece in such a manner that their contact pressures are mutually substantially compensated.

Abstract: A stapling machine is provided of the type which includes at least one stapling cylinder having a wire transport, a shaped disk which for the formation of the staples bites into a peripheral recess provided in the stapling cylinder, and a fixed staple guide which, with reference to the rotational direction of the stapling cylinder, is positioned after the shaped disk, projects into the peripheral recess and is underrun by the finished staple. The stapling machine is characterized in that the staple guide has, in the area of its surface which is underrun by the back of the staple, a post-bending edge which bites deeper into the recess in the stapling cylinder than does the outer periphery of the shaped disk.

Abstract: A process for determining the effective doping agent content of hydrogen the production of semiconductors which comprises zone drawing a silicon rod of highest purity and having a known specific resistance, in the presence of hydrogen to be tested, subsequently redetermining the specific resistance of the silicon rod, and computing the concentration of the doping agent in the hydrogen used from the known relationship between the specific resistance and the amount of doping agent. By stepwise determination of the resistance along the longitudinal axis of the rod, the amount of doping agent built into the rod at different levels can thus be determined.

Abstract: According to the invention, .alpha.-chloracetoacetamides, which is to be understood as including both .alpha.-chloro-N-monoalkylacetoacetamides and .alpha.-chloro-N,N-dialkylacetoacetamides, the alkyl radicals of which contain 1 to 3 carbon atoms, are produced by reacting the corresponding acetoacetamides with chlorine in aqueous solution at temperatures in the range of from -1.degree. C. to -25.degree. C. At a conversion of at least 95%, a selectivity of at least 97% and a yield of at least 95% of the theoretical yield, calculated on reacted acetoacetamide, are obtained.

Abstract: A support for mounting solar energy collectors on a roof of a building, which roof has an opening in the roof sheeting, includes a shell having a generally flat rectangular base and an upstanding edge secured to, and extending about the periphery of the base and a frame secured to, and extending about, the periphery of the shell. The frame is configured and dimensional to correspond to the outer surface shape of the roof sheeting and to permit mating receipt thereof in the opening of the sheeting.