Abstract: A burette top vent which resists air blockage includes a peripherally skirted cap having a generally planar circular base transfixed by a short integral tube having an upper portion to which tubing from a source of fluid may be attached and a lower portion from which fluid can drip into the burette. The base is perforated by an array of arcuate slots that permit air to enter the burette, and the bottom surface of the base has a shallow annular relief intersecting the slots. A ring-shaped hydrophobic filter disk hermetically affixed beneath the relief. The relief prevents the filter disk from lying flush against the bottom surface of the base.

Abstract: A process for protecting the 2'-hydroxyl of a nucleoside, which can then be used in the chemical synthesis of polyribonucleotides, comprising the reacting of a protected nucleoside of formula I ##STR1## wherein B is a nucleoside heterocyclic base and R' is a hydroxyl-protecting group,with 1-N-aryl-4-alkoxy-1,2,5,6-tetrahydropiperidine of formula II ##STR2## wherein Ar is an aryl group possessing an electron-withdrawing substituent which renders said protecting group acid labile and R is C.sub.1 -C.sub.

Abstract: A ventilator for clothes dryers and the like includes a counterflow heat exchanger through the wall of the building containing the apparatus, with an entry passage for ambient air entering the building and an exist passage for heated waste air leaving the building. An external housing defines an outlet chamber communicating with the exit passage, and an inlet chamber communicating with the entry passage. The chambers are both open to the ambience, and the two openings are adjacent one another, with a damper mounted for pivotal movement between a closed position in which the damper closes both of the openings, and an open position in which it opens both of the openings. The damper is biased toward the closed position, but is moveable toward the open position by a build-up of air pressure in the exit passage.

Abstract: Method of measurement of the total length of a yarn formed winding material (3) running onto a wound package (1), in particular a yarn web running onto the winding beam of a winding machine. During continuous winding operation, the length is ascertained by means of a measuring roll (2) over which the material to be wound (3) is guided. During acceleration and braking procedures, slippage occurs between the material to be wound (3) and the measuring roll (2). On occurrence of slippage, the system of measurement is changed, and the length of the wound package is determined from the rotational speed of the wound package (.omega..sub.w) and the circumference of the wound package (1). The circumference of the wound package (1), as well as the increase of the wound package circumference per rotation of the wound package, are ascertained during continuous winding operation.

Abstract: A poultry slaughtering machine includes a shackle conveyor for carrying a series of birds, suspended by their feet in a predetermined orientation with their breast facing to one side, along a first path, and a head capturing device disposed generally below the shackle conveyor and offset away from the breast side. The capturing device includes a flexible carrier constrained to follow an endless second path, a series of pairs of relatively movable jaws affixed to the endless carrier, and a cam rail for closing each pair of jaws about the neck of a bird. A rotary blade incises major blood vessels of tile neck, but is prevented from cutting the trachea or the spinal cord, and the jaws are opened to release the neck as soon as the cut has been made.

Abstract: An inline valve includes a glass body having an upwardly open bore with a tapered seating surface, and colinear inlet and outlet ports having passages intersecting the seating surface. Fluid flow between the ports is regulated by a valve member whose stem has a tapered tip conforming substantially in shape to that of the seating surface. The tip has a relatively soft surface which can conform to irregularities in the seating surface when the valve is closed. An annular seal or an extensible boot prevents fluid leakage along the valve stem.

Abstract: An unlimited width dovetailing system for holding a workpiece and guiding a router while cutting dovetails in an upper edge of the workpiece includes a base plate with a pair of blocks attached thereto, and a beam which rests on the base plate, abutting against the blocks. A dovetail template for a router is affixed to the beam, which can be turned end-for-end to expose either side of the template to the workpiece.An overhead clamping mechanism for holding the workpiece in a vertical plane against a front face of the beam includes a pair of bars each having a fixed jaw pivotally bearing against a respective one of said blocks and having an offset which extends over the workpiece's upper edge, a pair of movable jaws, one on each of the bars, an elongate clamping member extending between the jaws, and a pair of clamping screws, each passing through a threaded hole in its respective jaw and into said elongate member.

Abstract: A variable position endotracheal tube holder includes a face piece having an arcuate transverse portion adapted to pass between the nose and upper lip of the patient, and a pair of downwardly extending wings at either end of the transverse portion. The lateral portion of the face piece has upper and lower flanges protruding away from the patient's face, and defining a groove or way which receives and retains a movable support for holding the endotracheal tube. The support includes a slider which can be locked in various positions along the groove, and an integral tube hanger bracket extending downward to the tube.

Abstract: An engagement device ensures that a plug portion (1) is held, secure against tension, in a sleeve portion (3). The engagement device has at least one locking catch (5) which is able to be engaged behind a locking element (6) when the plug portion is completely inserted. To release the lock, a releasing lever (7) is provided next to the locking element (6), with which the locking catch is able to be disengaged from the locking element. This releasing lever is formed as a double armed lever which is able to pivot on the plug portion. Through that, no excessive force must be exerted onto the sleeve portion in order to withdraw the plug portion.

Abstract: A mold for casting an inverted base section of a manhole includes a core for forming an inner surface of the base section, and a jacket surrounding the core for forming an outer surface of the base section. A domed plate atop the core but below an upper edge of the jacket, and having a peripheral shape corresponding to that of the core, seals off the interior of the core and produces the floor shape of the base section. A trough former is placed between opposite interior sides of the jacket and above the domed plate. The flanges of the trough former are cut along arcs conforming to the shape of the domed plate so that cementitious material poured into the mold does not leak between the domed plate and the trough former. Hole formers are similarly seated atop the trough former.

Abstract: The aeration field of an aerator membrane is formed by perforating the membrane with a rotary device having a plurality of perforating tools. The membrane also rotates while it is being perforated, and the membrane and tool simultaneously move in a radial direction, with respect to the membrane, so that a spiral line of perforations results.

Abstract: A stretch film wrapping device includes a frame supporting at least one flexible hollow handgrip. An end of a core of a roll of stretch film is inserted into the hand grip, so that braking force on the film may be regulated by squeezing the hand grip as film is applied to an array of articles. The device also supports at least one reel of auxiliary narrow band material on an axis different from that of the stretch film roll, so that the band material and the stretch film may be simultaneously applied.

Abstract: A mid-roof anchoring system includes a series of anchoring channels secured to the roof structure along a line midway between the eave and the ridge of the roof. Metal roof panels installed over tile substructure are permitted to float laterally on the roof, except where they are attached to the anchoring channels. As a result, the roof panels expand or contract in both directions away from the midway line. This approach minimizes thermally induced movement the upper and lower edges of the roof, and minimizes reaction forces at the anchor.

Abstract: The probe for biomodulation is disclosed. The probe includes a semiconductor laser and a drive circuit which causes the laser to generate pulses in bursts. The pulses themselves are of nanosecond or picosecond duration, while the bursts are of millisecond, microsecond, or nanosecond duration. The pulses can be delivered at rates up to 3 GHz. The probe also includes a heat sink as the body contacting portion.

Abstract: A roofing system includes a strong nonmetallic mesh placed over an array of purlins, and secured to the periphery of the roof. Metal roofing panels, insulation, and a weatherproof layer are laid over the mesh. The mesh has sufficient strength to protect workers on the roof from falls, and sufficiently small openings to catch dropped tools and fasteners.