Abstract: A method and system of identifying a rotor of a centrifuge employ an approach that uses two tiers of model selection. Firstly, the moment of inertia of a rotor is calculated for a first measured acceleration. The indication of moment of inertia is utilized to disqualify a number of rotor models and to select a subset of models. In a second tier, windage power of the rotor is calculated in a manner that isolates windage from inertial drag. In one embodiment, drive torque is measured with the rotor operated at a high constant speed. Alternatively, windage is calculated using data obtained during a second measured acceleration. The accuracy of the computation is enhanced by taking into account the moment of inertia as one form of resistance to the second acceleration. Based upon the indication of windage power, at least one rotor model within the subset is disqualified. Upon identification of the rotor, the centrifugal process can be maintained at a maximum safe speed.

Abstract: A centrifuge rotor and method for gradient density separation which supports a generally cylindrical volume of sample solution with its axis inclined to the spin axis at an angle which is optimized for maximum separation efficiency while reducing contamination by undesirable centrifugates upon reorientation of the desirable centrifugates. The optimum angle is determined based on the relationship .theta.=Tan.sup.-1 (D/15L).sup.0.5 where D and L are respectively the diameter and length of the cylindrical volume of the sample solution and .theta. is the angle of inclination.

Abstract: A centrifuge hub-rotor drive is disclosed in which a rotor has an internal recess that fits over and interfaces with a hub. The hub has a skirt with a curved outer periphery that interfaces and contacts internal walls of the rotor which define a tapered section of the recess. The curved outer periphery of the skirt ideally meets the internal tapered walls of the rotor along a curved contact band. The outer periphery of the skirt is taken from a portion of a spheroid, regular, oblate or prolate.

Abstract: Data processing system for high-speed reproduction of musical recordings at a point-of-sale terminal utilizes optical CD music ROM banks of master programs prerecorded by a Dolby ADM (adaptive delta modulated) technique to condense their "information" content. Condensation permits higher data throughput during high-speed reproduction. In a "premastering" process to make encoded masters, a special multiplexer board provides interfacing between Dolby ADM digital audio data and a conventional data processing system. The multiplexer board performs computer-like data blocking and also writes a unique sync code directly in the data block. The data processing system also catalogs and edits the blocked digital audio; places encrypted catalog, pricing, and other indicia in the data file representing the music; and sends the data file to convention 16-bit PCM file writer for making the encoded CD music ROMs which contain the ADM data representing the encoded audio program.

Abstract: A synchronizer for synchronizing a slave tape recorder to a master tape recorder. When the speed of the master recorder exceeds 2.5 times the nominal play speed, the synchronizer causes the slave recorder to lag behind the master recorder by an amount related to the speed of the slave recorder. At lower speeds, the synchronizer causes the slave recorder to lock onto the position and speed of the master recorder. The synchronizer employs time-code readers to read time-code on address tracks on the master and slave recorders. The time-code readers produce not only time-code but also clock pulses which are employed to determine the speed of master and slave with high resolution. Both the time-code readers and a resolver employed in the synchronizer are constructed from gate assemblies rather than processors to reduce execution times for the processor in the synchronizer.

Abstract: A slotted retaining plate for use in a tubular reactor within an analytical system. The reactor contains inert packed material which provides for the necessary flow path length for a fluid stream entering the reactor. The retaining plate is extremely thin and has an array of slots which permit the necessary flow of the stream through the reactor, but retain the packing material within the reactor. The design of the slot array in the retaining plates essentially eliminates any possible impediment to the stream flow. The slots are adjustable to provide more flexibility in slot size control to allow use of smaller packing particles within the reactor and improve the instrument resolution in, for example, an amino acid analyzer.

Abstract: A swinging bucket centrifuge rotor including seating surfaces having shapes which cause buckets seating thereon to be relieved of side loading forces. Each bucket is symmetrical and is pivotally supported by bucket pins that rest in respective spring-loaded carrier assemblies. The spring constants of the springs of the carrier assemblies are selected so that the leading edge of each bucket bottom rests upon a curved surface and clears the respective seating surface before the trailing edge thereof contacts the same. The resulting bucket orientation assures that, upon seating, each bucket rotates until its bucket pins lift slightly off of the surfaces of the respective carrier assemblies.

Abstract: A torque-transmitting connector is disclosed which fits between a spindle and the walls of a bore in a rotating member. The connector includes a sleeve encircling the spindle and two flanges located at its opposite ends. Each flange is initially frustoconical, and is forced into substantially a disc shape to grip the spindle and the wall of the bore. The flange at the bottom of the bore is flattened first by a small diameter punch acting against the other end of the sleeve; and the other flange is then flattened by an annular punch encircling the small diameter punch.

Abstract: An elongate straight column for use as a reactor in an analytical instrument. The column contains inert packed material which provides for the necessary flow path length for a fluid stream entering the reactor. Fittings are incorporated onto the ends of the column in such a manner that their width is no larger than the width of the column. The column configuration for a reactor allows more versatility in the type of temperature regulator mechanisms used to heat and cool the reactor.

Abstract: A sealed bowl rotor having a transparent lid for easy visual checking of rotor contents. The lid has sealing means that automatically creates a seal which prevents the escape of liquid samples from within the rotor when the lid is placed on the rotor. The rotor design prevents the application of any possible hydraulic loading on the transparent lid. The installing/removing mechanism on the lid provides the capability for removal of the lid after the centrifugation run without disturbing the contents of the samples within the rotor.

Abstract: A method of closing or sealing a filler passage formed in a neck or stem protruding from the small access opening in the upper end of a substantially closed centrifuge tube. The neck is formed of a readily fusible material and a heat conductive cap member is positioned over the open end portion of the neck closely confining it therein. Heat and pressure are applied to the cap causing progressive portions of the neck to melt and fold into the filler passage where it forms a molten mass within the filler passage above the access opening to the tube. Heat and pressure are removed, permitting the cap to cool and the molten mass to solidify completely sealing or filler passage of the centrifuge tube. The cap is then removed and the centrifuge tube is fully prepared for centrifugation.

Abstract: A method and apparatus for layering a liquid sample onto a support liquid through a narrow filler passage in a neck protruding from the opening in a substantially closed, flexible centrifuge tube by supporting the tube with its liquid support contents in an upright position, attaching a funnel shaped container to the neck of the tube, applying a squeezing force to the flexible tube to reduce its internal volume thereby forcing the liquid contents into the neck thereof to form a meniscus adjacent the opening of the filler passage, adding a sample liquid into the funnel shaped container above the filler opening and in contact with the meniscus of the support liquid, and releasing the squeezing force from the tube allowing it to return to its normal volume thereby drawing the sample into the tube layered on top of the support liquid.

Abstract: A valve construction in the form of a "flex-finger" or flexible stem valve is provided for handling substances which are highly corrosive or very active chemically. The valve body, valve seats, a valve ball and flexible finger or flexible valve stem are all composed of chemically resistant material. The flexible stem has an outer end secured in the valve body against rotation with a fluid tight joint and an inner end for actuating the "ball". The flexible stem is composed of material which is sufficiently resilient so that it may be caused to travel in a circular or orbital path carrying or actuating a "ball" or other attachment into and out of engagement with the valve seat or seats.

Abstract: A small ball valve for chemically active materials is provided which does not require the strength of metal parts and which permits the use of brittle material such as glass or ceramic as well as materials such as fluorocarbon polymers and polytetrafluoroethylene which are resistant to the action of chemically active fluids. A free-floating construction is provided without requiring a stem packing gland and permitting the stem to be integral with the ball. Identical sealing rings are provided with clamping screws which press the sealing rings inward against the ball and outward against the openings in the valve body, the diameter of the valve stem being smaller than the opening in the sealing ring and clamping screw therefor so that the portion of the ball surrounding the valve stem may also float freely under the sealing means with the seal around the ball stem being against the ball itself instead of against the valve stem.

Abstract: A light beam is passed through a cuvette, through which flows liquid to be analyzed optically for concentration of color reacted amino acids. The emergent beam is directed through a series of dichroic beam separators and pass band filters to produce three beams of substantially three different wavelengths. Photoelectric detectors produce electrical signals corresponding to each of the three wavelengths. Two of the signals are characteristic of the substance to be detected. The third is subtracted from the other two wavelength signals to produce a pair of output signals from which base line noise has been substantially eliminated.

Abstract: A centrifuge rotor and method for gradient density separation which supports a generally cylindrical volume of sample solution with its axis inclined to the spin axis at an angle which is optimized for maximum separation efficiency while reducing contamination by undesirable centrifugates upon reorientation of the desirable centrifugates. .Iadd.The sample solution is contained in a centrifuge tube which is closed at its top end by a top portion which is supported by a support cap. The undesirable centrifugates are pelleted to the end corners of the inclined centrifuge tube. The rotor and method are particularly adapted, for example, for separation of nucleic acid into plasmid DNA and chromosomal DNA by density gradient centrifugation. .Iaddend.The optimum angle is determined based on the relationship .theta.=Tan.sup.-1 (D/15L).sup.0.5 where D and L are respectively the diameter and length of the cylindrical volume of the sample solution and .theta. is the angle of inclination.