Abstract: A dispersion having an aqueous phase is filtered by a purality of membranes connected to pass the retentate or a portion of the retentate from one membrane step is used for feeding the one or more succeeding steps, and the permeate resulting from the plurality of membranes is subjected to a concentration step to produce a concentrate containing an increase concentration of dry matter, which is returned as a portion of the feeding dispersion to one or more of the plurality of membranes. The system provided with the membranes and concentration units and recirculation conduits is also disclosed.

Abstract: An adjustable grade stick and method of using the same are used to identify a reference line. The grade stick has a shaft that is adjustable along its length. In a preferred embodiment, the shaft has two sections where one section lies within the other in a variably telescoping manner. A locking device is provided to lock the relative positions of the first and second sections of the shaft. A hook is located at one end of the shaft to mount the shaft on the ceiling of the mine tunnel. A sighting ring is located at the other end of the shaft and has an inner aperture which acts as a marker for a reference point. A calibration scale is located on the shaft for positioning the sighting means at a predetermined location. The reference line is sighted from the sighting rings of a pair of grade sticks.

Abstract: A process for manufacture of articles comprised of polyethylene terephthalate wherein the PET is colored with a composition comprised of a wax dispersant, ethylene copolymer, and a colorant. In a preferred embodiment, the wax dispersant is a maleated polyethylene wax. In an alternative embodiment, the wax dispersant is a low molecular weight polyethylene wax and the composition further includes linear low density polyethylene. A preferred ethylene copolymer is ethylene-(meth)acrylic acid.

Abstract: Differential outputs produced by twin thermoresistive sensors are used to determine the level and flow of a medium. Separate constant current sources supply power to each sensor so that one constant current source supplies sufficient current to cause significant self-heating of the sensor (hot sensor) and the other constant current source supplies relatively little current with insignificant self-heating of its corresponding sensor (cold sensor). Resistive changes in the sensors produced by level and flow changes of the medium produce measurable voltage changes, thereby providing a convenient parameter by which to determine level or flow. Level or flow is determined by dividing the difference in the voltages across the hot and cold sensors by the voltage across the cold sensor.

Abstract: A dispensable, disposable cover for stethoscopes prevents the transfer of disease or other contaminants through the incorporation of a shield of any geometric shape, having an adhesive backing for removably attaching the shield over the entire surface area of a diaphragm of a stethoscope. The shield is peelably detachable from the stethoscope diaphragm after use. In alternate embodiments of the cover, the shield has extending therefrom a pull-tab or a flap. In another embodiment, an annular lip sized for receipt by the stethoscope diaphragm is upraised from the cover and has the adhesive backing thereon, with the remainder of the cover having no adhesive backing and acting as the flap.

Abstract: A training apparatus for improving the performance of a swimmer. In a first aspect of the invention, a propeller rotates about an axis which is aligned with the path of the swimmer. A permanent magnet driven by the propeller attached to the swimmer produces a rotating magnetic field which acts on a magnetic field transducer to produce a pulsating signal whose frequency varies directly with the swimmer's speed. The sensor's output is multiplied, amplified and fed to an earphone worn by the swimmer. Changes in frequency immediately inform the swimmer of whether his performance has improved or deteriorated.In a second aspect of the invention, permanent magnets are mounted on vanes of an impeller which rotate about a horizontal axis which is at right angles to the path of the swimmer. Rotating magnetic fields of the permanent magnets act on a magnetic field sensor to produce a pulsating signal whose frequency varies with the swimmer's speed.

Abstract: A lock having a hand-slideable lock-bolt. A lock body has a transverse bore passing therethrough and in which the lock-bolt can be mounted. The lock-bolt is movable between locking and unlocked positions. A retention element located in the lock body but externally operable prevents the lock-bolt when in the unlocked position from being removed from the lock body. By externally manipulating the retention element the lock-bolt can be released for complete removal from the lock body. A key operable lock cylinder is located in the lock body and prevents the retention element from being manipulated to release the lock-bolt for removal unless a key is inserted in the lock cylinder and the lock cylinder is in an unlocked position.

Abstract: A tamper indication system for use with combination locks can indicate or signal that unauthorized manipulation of one or more of the lock components has occurred. In one mode, the tamper indication system senses unauthorized retraction of the lock bolt. Unauthorized movement of the lock cover or combination dial can also be sensed. Sensing can be achieved by generating a mechanical action responsive to the unauthorized manipulation and converting the mechanical action into an electrical signal for sensing and indicating. The mechanical action can utilize a snap action motion generation system, non-contact means such as magnets or a spring biased switch.

Abstract: An apparatus and method are provided for bypassing the emitter ballast resistors of a power transistor, thereby increasing transistor gain. In a power transistor of the interdigitated type, bypassing the emitter ballast resistors requires bypassing each individual ballast resistor with a capacitor in parallel. Bypassing is therefore done on the silicon chip. More particularly, in accordance with one embodiment of the invention, an RF power transistor includes a silicon die, an emitter ballast resistor formed on the silicon die, and a bypass capacitor formed on the silicon die and connected in parallel with the emitter ballast resistor. The resistor may be a diffused resistor, and the capacitor may be a metal-on-polysilicon capacitor.

Abstract: The invention relates to a hot air oven for the preparation of foodstuffs, with a housing with four housing side walls, a bottom and a housing cover, with a cooking chamber delimited by four side walls 4 as well as a bottom 2 and a ceiling 3, with a first blower 6 for generating a hot air flow in the cooking chamber, with a rotatable basket 5 for the foodstuffs, which can be inserted into the cooking chamber, wherein the hot air stream flows through the basket 5 during oven operation, with a control device for the course of the cooking progress, wherein the control device includes a temperature control, and with at least one incoming air conduit and at least one air outlet conduit 6, wherein at least one separation device 10 serving to separate out particles conveyed in the hot air flow is provided.

Abstract: The control circuit includes a reference MOS transistor (24) on which preermined operating characteristics are imposed. Circuitry (21, 22, 23) is provided for comparing an operating characteristic of the transistor (24) with a reference value (V.sub.tnref) so as to produce a control voltage. This voltage, after adaptation, is applied to the transistor (24) so as to fix the threshold voltage (V.sub.th) thereof, in such a way as to maintain the operating characteristics of the transistor (24). This same threshold voltage is then imposed on all the transistors of the logic circuit with which the control circuit is associated. This control circuit makes it possible particularly to reduce the consumption of said logic circuit.

Abstract: Apparatus for removing tie wires from bales includes a table for receiving a bale having a plurality of tie wires wrapped transversely around the bale, a rear stop engageable with the rear side of the bale when on the table, a main carriage movable transversely of the table towards and away from the rear stop and including a front stop engageable with the front of the bale for firmly holding the bale between it and the rear stop, and a cutter assembly movable longitudinally of the table adjacent to one of the stops for cutting the tie wires of a bale when firmly held between the two stops.

Abstract: The invention concerns a press section for a paper machine with at least two presses which are successively passed by a web to be dewatered, the web alternately making contact with a press felt and a closed shell surface of a press roll. The first press is fashioned as a single-felted shoe press and configured such that the one web side will make contact with a first smooth press element. The second press is fashioned single-felted as well and configured such that the other web side makes contact with a second, smooth press element. A web transport system is provided between each two adjacent presses. The invention is characterized in that the web transport system features a guide roll with smooth shell surface serving to pick up the web, at least during normal operation, directly from the smooth press element of the first press.

Abstract: In a packaging machine through which products are advanced singly and in succession along a wrapping line together with a heat-sealable wrapping film, the film is folded around each product to form a wrapper of tubular appearance with two facially confronting longitudinal edge margins, whereupon the temperature of the edge margins is raised by electromagnetic induction to soften the material in readiness for heat-sealing. The pressure required to fuse the heated confronting edge margins together is applied evenly from two opposite sides.

Abstract: Process for increasing the proportion of the .beta.-modification in polypropylenes, in which the polypropylenes are melted together with dicarboxylic acid salts of metals of the 2nd main group of the Periodic Table as .beta. nucleating agents and optionally with further conventional additives and are cooled, and polyropylenes which contain dicarboxylic acid salts of metals of the 2nd main group of the Periodic Table as .beta. nucleating agents.

Abstract: In an automatic planting apparatus (10) a first predetermined number of pieces of blocks (4) in the first row of a plant supporting sheet (3) on a sub-conveyer (13) are torn off by a block separator (25). The blocks (4) that are torn off are inserted into holes (2) in the first row of a panel (1) on a main conveyer (11) by a block inserting unit (39). The panel (1) is then fed forward by a row pitch by a main feeder (15) and slid laterally with the sub-conveyer (13) by a distance corresponding to the width of each block (4) by a sliding unit (17). The block inserting operation is then repeated.