Abstract: An apparatus for testing and processing a magnetic disk. The apparatus comprises a spindle for rotatably supporting the disk about a spindle axis; a first read and/or write head; a second read and/or write head; a gliding head; and a burnishing head, where the heads are selectively positionable along parallel axes overlying the magnetic disk; and a controller for selectively driving said heads across the magnetic disk and for selectively rotating the spindle in first and second directions.

Abstract: Apparatus and methods for the measurement of total organic carbon, total inorganic carbon and total carbon of water are described. The sample is acidified and split into an inorganic carbon stream and a total carbon stream. The inorganic carbon in the inorganic stream is oxidized and both the organic and inorganic carbon in the total carbon stream is oxidized. The resulting carbon dioxide is measured in each stream using carbon dioxide sensors employing a gas permeable membrane dividing deionized water from the oxidized sample water and a pair of micro-conductivity and temperature sensors.

Abstract: A dynamically variable digital delay line includes a storage element, write control circuitry, read control circuitry and output rate control circuitry. Generally, the invention applies a predetermined throughput delay to a series of digital data elements by entering each digital data element into a storage element for an amount of time equal to the desired throughput delay, then extracting each digital data element and returning it to the original data path. While operating with a constant predetermined delay, the invention extracts digital data elements from the storage element at the same rate as digital data elements are entered into the storage element. When a change to the throughput delay is required, the invention changes the digital data element extraction rate with respect to the digital data element entry rate until the desired throughput delay is achieved.

Abstract: The disclosed detector system includes a two dimensional array of detectors for use in generating a volumetric scan of objects moving through a scanner. The array can comprise rows and columns of square detectors, or alternatively at least two types of detectors, one for providing high image resolution in a direction parallel to or within a plane containing the X- and Y-axes of a CT scanner, and the other for providing high image resolution e direction of the Z-axis of the scanner. Preferably, a first set of detectors is oriented in one direction and a second set of detectors is oriented in a different direction. The disclosed detector system may be used in connection with CT scanners and, in particular, with CT baggage scanners and is particularly useful for detecting the presence of thin objects such as sheet explosives within scanned baggage.

Abstract: A system for and method of compensating for performance differences in a set of information channels is disclosed. The system and method model each channel as linear and characterizes the channel by an offset and a gain. The system includes memory for storing the offsets and gains associated with the N channels. The system further includes means for mathematically adjusting the output of each information channel by that channel's associated offset and gain. The system further includes filters for reducing the effect of random noise on the measurements of the offsets and gains by generating signals representative of time weighted averages of the offsets and gains.

Abstract: Improved electrodialysis (ED) stacks are disclosed having one or more components selected from the group:a) cation exchange membranes having ion exchange groups predominantly sulfonic acid groups and a minor amount of weakly acidic and/or weakly basic groups or membranes which are selective to monovalent cations and simultaneously therewith, cation exchange granules selective to monovalent cations as packing in the dilute compartments;b) anion exchange membranes having as ion exchange groups only quaternary ammonium and/or quaternary phosphonium groups and substantially no primary, secondary and/or tertiary amine and/or phosphine groups or membranes which are selective to monovalent anions simultaneously therewith, anion exchange granules selective to monovalent anions as packing in the dilute compartments;c) as packing in the dilute compartment, anion exchange granules which are selective to monovalent anions, or cation exchange granules which are selective to monovalent cations, or cation exchange granules

Abstract: On an infusion hose for an infusion device on which a column of liquid is permanently maintained at least in one section of the infusion hose and on which adjacent to that section there is arranged ultrasound detector equipment the acoustic signal from which passes through the column of liquid and is used to detect inclusions of air in the column of liquid, the section of the infusion hose, with reference to the said infusion hose, incorporates substantially diametrically opposed contacts (3, 6) for making contact with the ultrasound transmitter and receiver, and the contacts (3, 6) are insulated from the surrounding region of the section by acoustic filters and/or dampers (2, 4).

Abstract: Improved process and apparatus for purifying paraxylene from mixed C8-aromatic feedstocks are disclosed in which the use of at least two crystallization stages operated at different temperatures in combination with a final product separator improves purity and recovery while reducing capital and energy costs.

Abstract: The invention provides an implantable apparatus which includes a power supply capable of converting non-electrical energy such as mechanical, chemical, thermal, or nuclear energy into electrical energy. The invention also provides a method of supplying energy to an electrical device within a mammalian body in which the mammal is implanted with an apparatus including a power supply capable of converting non-electrical energy into electrical energy, and non-electrical energy is transcutaneously applied to the apparatus.

Abstract: A variable capacitance fluid pressure sensor of the type which includes a deflectable member includes a contaminant exclusion system which protects the deflectable member from both solid and non-solid fluid-borne contaminants. A system of traps disposed between the fluid inlet to the sensor and the deflectable member prevents deposition of process vapors in the fluid on the deflectable member and collects a variety of sizes of fluid-borne solid contaminants remote from the deflectable member.

Abstract: An apparatus and process are disclosed for optimizing the repetitive steps in a solid-phase oligonucleotide synthesis by continuous optical scanning of the effluent stream from the reaction module and by computerized processing and implementation of the scanning data.

Abstract: An apparatus for energizing a large scale medical imaging system, preferably in the form of a CT scanner so that the scanner operates off an uninterruptable power supply in the event that the external power falls below sufficient power to operate the system so that system operation remains uninterruptable. The system is designed to operate off a broad range and types of external power supplies including those providing DC, single or three phase AC power. The system therefore can operate from a common single phase AC outlet. In addition, power factor correction is provided so that the system can correct for phase differences between the voltage and current at the input line created by the input impedance of the system.

Abstract: The disclosed pressure transducer assembly includes an external enclosure, a thermal shell disposed within the external enclosure, and a pressure sensor disposed within the thermal shell. The pressure sensor senses the gas or vapor pressure present in a tube coupling the sensor to a source of pressurized gas or vapor. The assembly includes a device for heating the thermal shell, and thermal insulation is disposed between the thermal shell and the external enclosure. The thermal insulation includes a plurality of metalized high temperature films stacked one on top of another and a plurality of spacer layers, each of the spacer layers being disposed between adjacent ones of the metalized high temperature films.

Abstract: An apparatus and method for communicating data between at least two data devices, suitable for use as a wireless local-area network, that provides robust data communication via a radio communications channel corrupted by multipath interference, particularly at high data rates. A preferred embodiment of the invention represents data as a sequence of Walsh-function waveforms encoded by pseudo-noise direct-sequence spread-spectrum modulation. Walsh-function-encoding of the data provides a long symbol duration, thereby allowing the spread-spectrum modulation to provide processing gain sufficient to substantially overcome multipath interference, while providing a high data rate. In another preferred embodiment, Walsh-function modulation is supplemented with various forms of phase modulation, such as coherent PSK for bi-orthogonal signalling, and DPSK between orthogonal symbols for noncoherent bi-orthogonal signalling, thereby further increasing data rate without reducing processing gain.

Abstract: A multi-channel mass flow transducer has a single laminar flow element in a primary fluid flow path and multiple secondary flow paths in parallel with and in fluid communication with the primary flow path. Flow restriction elements are disposed in one or more of the secondary flow paths to establish different flow rate measurement "channels" having particular flow rate ranges. The multi-channel transducer of the present invention is capable of measuring fluid flow rates over an extended range and eliminates the need for multiple transducers to measure varying fluid flows.

Abstract: A nutating slice CT image reconstruction apparatus and method generates a set of projection data using helical cone-beam scanning. The three-dimensional projection data is used to reconstruct a series of planar image slices. The slices are selected such that they define a tilt angle and a rotation angle with respect to the longitudinal axes of the object being scanned. Successive slices have equal tilt angles but changing rotation angles such that normal axes of successive slices define a nutation and precession about the longitudinal axis of the object. Projection data for the tilted slices are formed of selected one-dimensional fan-beam data. As such, the projection data can be applied to conventional two-dimensional reconstruction approaches to generate an image.

Abstract: A differential pressure transducer includes a pair of interior chambers separated by a peripherally supported, nominally planar electrically conductive diaphragm. A magnetic assembly is positioned on at least one chamber wall opposite to a central portion of the diaphragm. The magnetic assembly includes an electrical conductor and preferably a magnetic field permeable electric field shield between the electrical conductor and the chamber so that as the central portion of diaphragm is displaced from its nominal plane in response to an applied pressure differential, the inductance of the magnetic assembly changes. The transducer may be a portion of a tank circuit of an oscillator having a frequency of oscillation that varies with the pressure differential applied across the diaphragm.

Abstract: Apparatus and methods for the measurement of total organic carbon, total inorganic carbon, total carbon and total heteroorganic carbon of deionized water are described. In a preferred embodiment, the sample is split into a first stream and a second stream. Inorganic carbon in the first stream is measured using a temperature and conductivity cell, and then the organic carbon in the first stream is oxidized in a U.V. oxidation module. The resulting carbon dioxide is transferred through a carbon dioxide permeable membrane into the second stream. The second stream then passes into a second temperature and conductivity cell for the measurement of total carbon.

Abstract: A multiple angle tomographic system includes a rotating gantry with a source, e.g., an x-ray source, and detector array combination mounted thereon so as to acquire a plurality of projections of objects passing through the gantry. A pre-screen subsystem utilizes a subset of the projections from those that can be acquired during a full scan so as to define a first plurality of projections--e.g., eight projections--that are sufficient analyze whether there is a likelihood that a targeted object, e.g., a firearm and/or plastic explosives is present. If there is a likelihood that a targeted object is present, a full-image CT reconstruction is commanded, automatically or manually, so as to verify and more fully assess the detected object. This combination of pre-screen and selective full-image CT reconstruction provides thorough inspection of closed containers, e.g., passenger luggage, by providing multiple angle and perspective viewing of targeted objects.

Abstract: Variable-response photodetectors adapted to compensate for nonuniformity along an axis of a scintillating crystal by means of multi-element photodiodes and systems for selectively activating different photodiode sub-elements are disclosed, together with arrays of such photodetectors and X-ray detection systems utilizing such photodetectors.