Abstract: Powder compositions useful for making conductors, e.g. microcircuit conductors, end terminations for capacitors, electrodes for gas discharge display devices, etc. The compositions comprise inorganic powders dispersed in an inert vehicle and are printed and fired in the conventional manner on dielectric substrates. The inorganic powders comprise aluminum, silicon, and glass.

Abstract: A system of bypass passages adjacent bearing means in the drive system of an ultracentrifuge which operates in a vacuum environment. The bypass passages or channels are designed to prevent the establishment of a pressure differential across the bearings in the drive system when a vacuum is being pulled or exists around the drive system when it is operating. The unique bypass system prevents the loss of lubricating material within the drive system during air evacuation of the drive system and the rotor chamber when a vacuum environment is being established within the rotor chamber. Also, the bypass system promotes a more uniform and constant flow of lubricating medium in the bearings.

Abstract: A multi-channel instrumentation system is provided wherein signals from selected electrode pairs are sequentially connected to the isolated input of a common signal amplifying path. The electrode pair selecting means is included in a portable head box which may be placed adjacent to the patient to be tested. Included in the head box are facilities for testing the impedance of any selected one of the patient electrodes and providing a visual indication of the magnitude of such impedance. The head box also includes facilities for selecting a group of patient electrodes which are connected together and used as an average or reference potential for one input of the common signal path. Facilities are also provided for calibrating the common signal path by applying a d.c. calibration signal to the input thereof by means isolated from system ground.

Abstract: A method and apparatus for detecting the absence of a coded overspeed disk used to indicate the maximum design speed of a rotor which is rotatably connected to a high speed centrifuge. Two donut-shaped coded disks, one mounted on the drive shaft on the centrifuge and the other mounted on the centrifuge rotor are utilized. Optical emitter sensor assemblies are used to produce speed control and overspeed signals. By sensing the light reflected back to the optical sensor from the drive system hub, the rotational speed of the centrifuge is indicated. By sensing the light reflected back to the optical sensor from the overspeed disk mounted on the rotor, the rotation of the rotor is detected. In the absence of an overspeed disk, the speed control frequency will exceed that of the overspeed disk.

Abstract: A method for isolating D and L amino acids from a racemic mixture of the formula(DL)--H.sub.2 N--CHX--COOY,and salts thereof, wherein X denotes an amino acid side chain and derivatives thereof and Y denotes a suitable alkyl group. The racemic mixture is contacted with water to form an aqueous solution. This aqueous solution is then contacted with an esterase to thereby obtain a solution comprising the resolved amino acids(L)--H.sub.2 N--CHX--COOH and(D)--H.sub.2 N--CHX--COOY.The N-terminus of the resolved (L) and (D) amino acids present in this solution are protected with an N-protecting group R to thereby obtain a solution comprising(L)--R--NH--CHX--COOH and(D)--R--NH--CHX--COOY.The isolation of (L)--R--NH--CHX--COOH from (D)--R--NH--CHX--COOY is achieved in high yields by an acid-base extraction.

Abstract: A method of determining the need for post-addition of antigen or antibody to an antigen-antibody reaction to ascertain whether the reaction is in an antigen excess or an antibody excess condition. The time rate of change of a nephelometric signal developed from the reaction is monitored to generate a rate signal having a peak value providing a measure of antigen concentration. The post-addition step is performed only if the peak rate value is ambiguous--, i.e. if it indicates one antigen concentration value for a reaction in antigen excess but another value for a reaction in antibody excess. The need for the post-addition step is determined from measured qualities of the rate signal including one or more of (1) the peak rate value, (2) the elapsed time from the start of the reaction to the peak rate, and (3) the product of the peak rate and the elapsed time. When required, the post-addition step may be performed during progress of the antigen-antibody reaction after measurement of the peak rate value.

Abstract: A multi-channel instrumentation system is provided wherein signals from selected electrode pairs are sequentially connected to the isolated input of a common signal amplifying path. The electrode pair selecting means is included in a portable head box which may be placed adjacent to the patient to be tested. Included in the head box are facilities for testing the impedance of any selected one of the patient electrodes and providing a visual indication of the magnitude of such impedance. The head box also includes facilities for selecting a group of patient electrodes which are connected together and used as an average or reference potential for one input of the common signal path. Facilities are also provided for calibrating the common signal path by applying a d.c. calibration signal to the input thereof by means isolated from sytem ground.

Abstract: A rotor apparatus utilizing a lid having an enlarged rim portion which under centrifugally induced forces will move into close sealing contact with the lower portion of the rotor. The lid portion of the rotor is a generally flat circular disc with the thicker rim portion of greater mass located around the periphery of the circular disc. The slight deflection of the lid during centrifugation provides an automatic increase in the seal between the lid and the lower portion of the rotor as the rotational speed increases. The automatic tightening feature enables the user to merely hand tighten the lid onto the lower portion of the rotor without having to use some type of mechanical advantage tool. The lid has a relatively large diameter and contains no holes in order to reduce possible material stress in the lid during centrifugation. The lid is threadably connected to the lower portion of the rotor by a depending stud projecting from the bottom surface of the lid.

Abstract: Apparatus for automatically and selectively supplying a blood sample or a wash/calibration solution to the entrance port of a flow cell which measures characteristics of the sample such as pH, pCO.sub.2 and pO.sub.2. A sample filled syringe and a solution supply conduit are supported by respective first and second fluid delivery mechanisms which rotate to move the syringe outlet and the conduit outlet in generally arcuate paths toward and away from the flow cell entrance port. The delivery mechanisms are rotated simultaneously, one toward and one away from the entrance port, by a common drive gear. Seating of the wash solution outlet in the entrance port is upstream of the seating of the sample outlet to ensure complete flushing of sample from the entrance port by the wash solution.

Abstract: A stable blood serum bilirubin reference composition characterized in that said composition either (1) possesses a pH of from about 8.3 to about 9.5 or (2) further comprises a sulfhydryl compound in an amount sufficient to enhance the stability of the bilirubin or (3) both possesses a pH of from about 8.3 to about 9.5 and further comprises a sulfhydryl compound in an amount to further enhance the stability of the bilirubin.

Abstract: A mechanical overspeed protection device incorporated in a microtest plate carrier used in a centrifuge rotor. A locking arm actuates into a blocking position on the microtest plates in the carrier to indicate that the carriers on the rotor have been subjected to an overspeed condition during the centrifugation run. A housing within the carrier microtest plate retains the arm in an unactivated position during operation below a specified force field. However, when the carrier experiences an overspeed condition, the locking arm is designed to have sufficient weight, so that in response to the centrifugally induced forces the arm will move out of the housing into an outward blocking position on the carrier plates. The insertion of new microtest plates in the carrier for additional centrifugation runs is prevented, since the locking arm is in its blocking position.

Abstract: A closing structure for the top of a centrifuge chamber comprising a door which is slidable horizontally toward and away from closed position, a retaining member above the door which permits a limited upward movement of the door, side members which surround the closed door on three sides to contain shrapnel from a rotor failure, and a flange extending downwardly from the door on its fourth side to contain shrapnel.

Abstract: A vacuum operated system for transferring fluid from a container to an open or relatively large sump without applying vacuum to the sump. A small, closed, intermediate chamber is interposed in a flow path between the container and the sump. Vacuum from a small vacuum source is applied to the intermediate chamber and draws fluid from the container through a first conduit into the chamber. A peristaltic pump draws fluid from the chamber through a second conduit to the sump while maintaining a vacuum seal for the chamber preventing loss of vacuum through the second conduit.

Abstract: A carrier strip assembly of continuous length having transversely mounted round lead wires with an integrally formed resilient clamp on each end of each lead wire for connection with an electrical component substrate. The carrier strip provides the transporting means for the attached electrical component substrate for the assembly stages of the electrical component. The lead wires are severed from the carrier strip portion to provide outwardly extending round lead pins or external connects for interface with an electrical circuit assembly. The method for making the carrier strip assembly is disclosed.

Abstract: A screen printed capacitor to provide a predetermined temperature coefficient of capacitance. The capacitance device utilizes a common electrode with a uniform dielectric layer in conjunction with two side-by-side base electrodes resulting in opposite polarity temperature coefficient of capacitance values. The proportion of the area of each of the side-by-side base electrodes with respect to each other determines the predetermined temperature coefficient of capacitance required.

Abstract: This invention relates to a swinging bucket centrifuge rotor in which each bucket is supported by an independent bucket hanger member disposed within a cavity in the rotor. Each hanger member is spring biased in a radial direction toward the axis of rotation, and is supported by a guide sleeve with fastening means extending through the guide sleeve. The guide sleeve prevents rotation of the bucket and hanger member with respect to the rotor body.

Abstract: An improved method of storing and shipping a blood serum reference composition comprising in its non-biological component from about 40 to about 85 weight percent water, from about 15 to about 60 weight percent of at least one alkylene polyol having from 2-5 carbon atoms, the remainder being chiefly at least one natural biological material selected from a group consisting of blood serum, enzyme, metabolites, electrolytes, and hormones. The improvement comprises storing and/or shipping the composition at a temperature below the freezing point thereof.

Abstract: A heat exchanger comprising:(a) a housing having an interior surface;(b) a thermally conductive member in intimate contact with the housing;(c) a thermally conductive element coaxially disposed in said housing and having an inner and an outer surface and in thermal communication with the member, wherein the inner surface of the element defines a first fluid passage, and wherein the interior surface of the housing and the outer surface of the element are in spaced relationship thereby defining a second fluid passage, the first and second fluid passages being in fluid communication;(d) a first port for maintaining the first fluid passage in fluid communication with a first external fluid;(e) a second port for maintaining the second fluid passage in fluid communication with a second external fluid; and(f) means for regulating the member's temperature; wherein heat is transferred between the member and the element via solid conduction.

Abstract: A process for making the final seal in a gas discharge display using a piece of low temperature glass cane which is melted to form a generally flat seal within an access hole in one of the insulating plates of the display. The generally elongated piece of cane glass is inserted into an access hole in one of the insulating plates and after being exposed to a melting temperature it fills the access hole area in the insulating plate, leaving no protrusions on the outside surface of the display.

Abstract: A method and related apparatus for the reliable determination of a random coincidence count attributable to chance coincidences of single-photon events which are each detected in only a single detector of a scintillation counter utilizing two detectors in a coincidence counting technique. A first delay device is employed to delay output pulses from one detector, and then the delayed signal is compared with the undelayed signal from the other detector in a coincidence circuit, to obtain an approximate random coincidence count. The output of the coincidence circuit is then applied to an anti-coincidence circuit, where it is corrected by elimination of pulses coincident with, and attributable to, conventionally detected real coincidences, and by elimination of pulses coincident with, and attributable to, real coincidences that have been delayed by a second delay device having the same time parameter as the first.