A single-core transmission line transformer includes first, second and third transmission lines, and first and second ports. The first and second transmission lines are wound around a common core. The first port interconnects respective first ends of the first and second transmission lines in parallel. The second port communicates with respective second ends of the first and second transmission lines. The third transmission line communicates with the first and second transmission lines without being wound around any solid core. The impedance transformation ratio of the transformer is 1:9 in a direction from the first port to the second port.
H01P 5/10 - Coupling devices of the waveguide type for linking lines or devices of different kinds for coupling balanced lines or devices with unbalanced lines or devices
H01F 17/06 - Fixed inductances of the signal type with magnetic core with core substantially closed in itself, e.g. toroid
H01F 19/06 - Broad-band transformers, e.g. suitable for handling frequencies well down into the audio range
H03H 7/42 - Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns
An electrospray ionization device includes a sample conduit providing a sample flow path in a sample flow direction; a first gas conduit surrounding the sample conduit and having an annular outlet; a support structure surrounding the sample conduit; a housing surrounding the sample conduit and includes a first end at the support structure and an axially opposite open second end; and a second gas conduit. The first gas conduit provides a first gas flow path in the sample flow direction. The second gas conduit has a second gas inlet and a second gas outlet in open communication with the housing and provides a second gas flow path from the second gas outlet into the housing that is in the sample flow direction, surrounds the sample conduit and is constrained in a radial direction by the housing.
H01J 49/04 - Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locksArrangements for external adjustment of electron- or ion-optical components
G01N 27/62 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosolsInvestigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electric discharges, e.g. emission of cathode
A dissolution test vessel configured for direct vessel heating includes a lateral wall, a resistive heating element, and a temperature-sensing element. The resistive heating element and the temperature-sensing element are bonded directly to the lateral wall, and may be formed by dispensing flowable materials onto the lateral wall. The resistive heating element includes a contiguous first heating element end, heating element section, and second heating element end. The temperature-sensing element includes a contiguous first sensing element end, sensing element section, and second sensing element end. The vessel may communicate with a heater control system, which may be provided with a dissolution test apparatus at which the vessel is mounted.
A dissolution test apparatus includes a vessel support member, weight sensors, a movable component, a media transport cannula, a pump, and an electronic controller. The vessel support member receives vessels. A weight sensor is located at each vessel site. Each weight sensor contacts a vessel and transmits a measurement signal indicative of the weight of the vessel and any contents therein. The movable component moves the media transport cannula toward a vessel site. The pump establishes media flow between the media transport cannula and the selected vessel. The controller communicates with the weight sensors and may also communicate with the pump. Based on the measurement signals received from the weight sensors, the electronic controller may calculate the volume of media in a given vessel. The electronic controller may also control media flows to or from the vessels by transmitting control signals to the pump assembly.
Tracer gas leak detection is provided by a calibration system with a gas leak detector having a test port for receiving a sample containing a tracer gas and coupled to a vacuum pump; a calibrated leak for a calibration sample containing the tracer gas; a mass filter coupled to the test port for receiving the test sample in an operating mode, coupled to the calibrated leak through a calibrated leak valve for receiving the calibration sample in a calibration mode, having controllable transmission of the tracer gas and providing a filtered sample; detector detecting the tracer gas in the filtered sample; a programmable gain element providing a measured value of leak rate in response to the detector signal; and a controller configured, in response to a mode control signal, to operate the leak detector in the calibration mode over two or more working ranges using the calibrated leak.
G01M 3/20 - Investigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
G01M 3/00 - Investigating fluid tightness of structures
A flow cell device includes a body having a hollow bore in which a liquid sample may reside. An electromagnetic beam may be directed through the body and into the bore to irradiate the liquid sample. The beam may be directed orthogonal to an axis of the bore. A light ray produced as a result of the irradiation may likewise be directed orthogonal to the bore axis along the same plane as the beam, and received by a detector. The body may be secured between a liquid inlet structure and a liquid outlet structure.
An elongate sample volume matching an elongate region of uniform RF magnetic field established by a saddle coil, is approximated by at least one pair of cylindrical sample tubes in parallel orientation with the geometric axis of the saddle coil. The displacement of the two cylindrical tubes defines a direction transverse to the tube axes and 5 this transverse direction is aligned parallel with the RF magnetic field of the saddle coil.
G01N 24/08 - Investigating or analysing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
G01N 1/36 - Embedding or analogous mounting of samples
Remote adjustment of a selected one of a plurality of adjustable NMR probe circuit components is achieved with a plurality of selectable linear actuators, the selected one of which urges a platen against a respective driven gear, azimuthally locked to its shaft, to displace it axially along that shaft. When the driven gear engages a driving gear a single driving motor is energized and controlled to effect the desired adjustment.
An ion detector comprises an ion guide with electrodes arranged about a first axis; a positive ion detection device with an ion inlet at a first side of the ion output section offset from and at an angle to the first axis; and a negative ion detection device with an ion inlet at a second side opposite the first side, offset from and at an angle to the first axis. A negative voltage bias applied to the positive ion device accelerates positive ions toward the inlet along a path including a component along a second axis orthogonal to the first axis. A positive voltage bias applied to the negative ion detection device accelerates negative ions toward the inlet along a path that includes a component along the second axis orthogonal to the first axis in a direction generally opposite to the path of the positive ions.
H01J 49/04 - Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locksArrangements for external adjustment of electron- or ion-optical components
H01J 49/06 - Electron- or ion-optical arrangements
10.
SWITCHABLE MANUAL/MOTOR-DRIVEN NMR TUNING SYSTEMS AND METHODS
Motor-tuned NMR probes may be tuned manually without overcoming the tuning motor holding force. The NMR probe comprises a switchable manual-mode/motor-driven mode capacitance-adjustment assembly for adjusting the capacitance of a variable capacitor connected to an NMR RF coil which has a tuning shaft coupled to the variable capacitor through a gear assembly and a mode-switching coupler coupled to the tuning shaft. The mode- switching coupler comprises a first terminal coupled to a piezoelectric motor, and a second terminal coupled to the tuning shaft. In the manual mode, a user pushes up the tuning shaft, decoupling the two terminals of the mode- switching coupler and thus decoupling the motor from the tuning shaft, then manually rotates the tuning shaft. In the motor-driven mode, a spring tensioner presses the two terminals of the mode-switching coupler together, coupling the motor to the tuning shaft.
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
11.
ELECTRONIC NMR REFERENCE SIGNAL SYSTEMS AND METHODS
According to some embodiments, a synthetic nuclear magnetic resonance (NMR) reference signal is injected into the receive path of an NMR spectrometer, after the NMR probe and before the receive amplifier. The synthetic signal is generated using a transmit path for the same channel or for a different channel than the reference signal detection channel. The reference signal is coupled from a transmit-path reference signal coupler situated before a transmit amplifier to a receive-path reference signal coupler situated between the probe and the receive amplifier. The reference signal couplers may include passive directional couplers and/or active switches. The synthetic signal samples the receive path of the system but is not substantially affected by intra-probe interactions. Using a well-defined existing NMR channel to generate the reference signal allows superior control of reference signal characteristics, and does not require a dedicated spare channel for the reference signal.
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
G05F 1/00 - Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
12.
COMPLETE STRUCTURE ELUCIDATION OF MOLECULES UTILIZING SINGLE NMR EXPERIMENT
The complete structure of a molecule of interest is determined from a single NMR experiment utilizing a single NMR pulse sequence. The experiment utilizes the same pulse sequence for acquiring various one-dimensional and multi-dimensional spectra, with independent receivers tuned to individual resonance frequencies.
G01N 24/08 - Investigating or analysing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
A shutter and gate valve assembly includes a valve housing that defines a passage therethrough, a valve member having a valve aperture, the valve member movable between a non-operating position that seals the passage and an operating position that aligns the valve aperture with the passage, and a shutter movable between a closed position that blocks the valve aperture and an open position that unblocks the valve aperture. The shutter member may be affixed to and movable with the valve member between the non-operating position and the operating position. The shutter may be provided with a shutter aperture that is aligned with the valve aperture in the open position.
H01J 49/04 - Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locksArrangements for external adjustment of electron- or ion-optical components
G01N 27/62 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosolsInvestigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electric discharges, e.g. emission of cathode
14.
DIFFERENTIAL TUNING OF QUADRATURE MODES OF A MAGNETIC RESONANCE COIL
A coil assembly for transmitting or receiving radio frequency signals includes a coil, a capacitive tuning ring, a first capacitive shield, and a second capacitive shield. The coil includes axial conductors extending between first and second end regions and arranged about a longitudinal axis. The tuning ring is axially movable wherein an amount by which the tuning ring overlaps the plurality of axial conductors is adjustable. The first capacitive shield is axially movable relative to a first group of axial conductors wherein an amount by which the first capacitive shield overlaps the first group is adjustable. The second capacitive shield, offset ninety degrees from the first capacitive shield, is axially movable relative to a second group of axial conductors wherein an amount by which the second capacitive shield overlaps the second group is adjustable. The capacitive shields enable the coil to be quadrature balanced.
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
G01R 33/34 - Constructional details, e.g. resonators
G01V 3/00 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation
15.
CHARGE CONTROL FOR IONIC CHARGE ACCUMULATION DEVICES
A method for controlling charge flux into a charge accumulation device includes determining a charge accumulation time during which charges are to be accumulated in the charge accumulation device, measuring a charge flux of a first ion beam produced from an ion source, determining a target number of charges to be accumulated in the charge accumulation device during the charge accumulation time based on the measured charge flux and, based on the determined target number of charges, modulating a second ion beam produced from the ion source to cause the target number of charges from the second ion beam to be accumulated in the charge accumulation device during the charge accumulation time. An ion processing device is configured for controlling the charge flux. An ion beam modulator modulates the ion beam.
H01J 49/26 - Mass spectrometers or separator tubes
H01J 49/02 - Particle spectrometers or separator tubes Details
G01N 27/62 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosolsInvestigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electric discharges, e.g. emission of cathode
A method of operating a superconducting switch system to protect against quenching in a superconducting magnet circuit is provided. The system comprises a magnet circuit, a main superconducting switch and an auxiliary superconducting switch connected in parallel thereto by low resistance connecting parts. In an initial magnet energisation procedure, after establishing superconducting flow in the circuit, the main and auxiliary switches are closed to cause current to persist in the circuit without further power input. If the main switch quenches, the current will transfer to the auxiliary switch through the resistive connecting parts. Upon restoring the main switch to the superconducting state, the voltage drop through the resistive connecting parts will drive the current back through the main switch. A preconditioning procedure is carried out as part of the magnet energisation procedure to ensure that opening the main switch will establish superconducting current through the auxiliary switch.
H02H 7/00 - Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
17.
CRYOGENIC NMR PROBE CAPACITORS WITH DIELECTRIC HEAT SINKS
According to some embodiments, low-temperature (cryogenic) nuclear magnetic resonance (NMR) probe fixed capacitors include thermally-conductive dielectric layers serving to thermally connect the capacitors to a cryogenic heat sink. For example, a sapphire layer may be metalized on opposite sides to form copper capacitor plates, and along an edge to form a copper heat sink contact. Heat generated by RF currents during an operation of an NMR circuit including such a capacitor is discharged through the thermally-conductive dielectric to the heat sink. Cooling cold-probe circuit components such as capacitors through thermally-conductive capacitor dielectrics allows reducing perturbations introduced into the circuit by components such as heat sinks.
A multimode resonator resonating at two or more frequencies is operated at cryogenic temperatures and composed of a superconducting material or a normal metal with a superconducting section serving as a RF superconducting switch. The multimode resonator is coupled to a NMR spectrometer and a RF switch power source, wherein its one frequency is selected to correspond to the operating frequency of the NMR spectrometer and at least a second frequency is tuned to a frequency of RF switch power source, unrelated to the spectrometer frequency, therefore power at this frequency does not perturb the operation of the spectrometer. When activated, the RF switch power source induces a current sufficient to approach or exceeds the critical current in one or more sections of the superconducting material of the multimode resonator, thereby increasing its resistance and reducing the Q factor of the multimode resonator.
Sample material ionized in a sample receiving chamber is flowed into a sample conduit. Drying gas may also flow into the sample conduit and may be heated. The pressure and length of the sample conduit may be provided according to the product 50 or greater Torr-cm. The sample conduit may include a turn. The sample conduit may lead to an ion extraction chamber at which a sampling orifice may lead to a mass spectrometer. The diameter of the sample conduit may be larger than the diameter of the sampling orifice. An electrical field may be applied in the ion extraction chamber to slow incoming ions. A voltage jump may be applied to the sample conduit.
H01J 49/04 - Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locksArrangements for external adjustment of electron- or ion-optical components
According to one aspect, a nuclear magnetic resonance (NMR) radio-frequency (RF) coil of an NMR spectrometer includes oppositely-facing arches at opposite longitudinal ends of the coil window, along shielded regions of the coil. The arched coil shapes allow situating the transverse parts of the coil away from the interfaces between the sample measurement volume and coil shields while minimizing the additional coil length and thus coil inductance and capacitance needed to move the transverse conductors away from interfaces. Moving the transverse parts of the coil away from the measurement volume facilitates shimming. The coil may be lifted on a plurality of longitudinal support rods spaced around a circumference of the coil, in order to reduce the capacitance between the coil and associated shields.
A rotor drive apparatus includes a rotor and a stator. The stator has a gas injection orifice located on the axis about which the rotor spins. The gas injection orifice communicates with a bearing gap formed between a tapered surface of the rotor and an axially spaced tapered surface of the stator. A gas is flowed from the gas injection orifice through the bearing gap, thereby establishing a center-fed, radial- outflow gas bearing supporting the rotor during rotation. In one implementation, a separate flow of drive gas is fed to drive flutes of the rotor to drive rotation. In another implementation, the center-fed, radial-outflow gas flow is additionally utilized to impinge against the drive flutes to actuate the rotation.
H02K 7/00 - Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
A dissolution test apparatus includes an optical probe, an automated actuator. The probe takes an optics-based measurement in dissolution media contained in a test vessel and transmits the measurement to an analytical instrument situated remotely from the vessel. The optical probe is movable by the actuator into and out from the vessel. The dissolution test apparatus may include a bubble removal apparatus that communicates with the optical probe and is configured for transmitting a variable vibrating force to the probe, wherein bubbles are removed from a light path gap of the probe. In another dissolution test apparatus, the bubble removal apparatus rotates the probe to remove bubbles. Another dissolution test apparatus includes a movable cleaning mechanism, a movable calibration mechanism, or both mechanisms.
Devices and methods are provided for reducing matrix effects in protein precipitated bioanalytical samples comprising: a support, and a sorbent associated with the support capable of binding matrix interfering agents present in the bioanalytical sample, wherein the device further comprises filtering means for removing precipitated protein particles. The filtering means is a size exclusion filter or a polymeric or inorganic monolith having a maximum pore size less than or equal to the diameter of the particles to be removed from the sample, and can be integral with the sorbent or associated with the sorbent. The sorbent is characterized by sufficient selectivity between the matrix interfering agents and analytes of interest to provide retention of the matrix interfering agents while providing elution of the analytes of interest (e.g., a reversed phase or a polar modified reversed phase). Typical devices incorporating these features include luer syringe filters, individual filter cartridges, multiwell plates, pipette tips, or inline columns for multiple or single use.
C12Q 1/00 - Measuring or testing processes involving enzymes, nucleic acids or microorganismsCompositions thereforProcesses of preparing such compositions
C12Q 1/28 - Measuring or testing processes involving enzymes, nucleic acids or microorganismsCompositions thereforProcesses of preparing such compositions involving oxidoreductase involving peroxidase
C12M 1/34 - Measuring or testing with condition measuring or sensing means, e.g. colony counters
24.
SAMPLE PREPARATION DEVICE AND METHOD UTILIZING POLYMIDE TUBE
Polyamide sample preparation tubes with a hollow polyamide tube and an extraction medium contained within the tube are utilized in the sample preparation devices. The sample preparation tubes are substantially inert and show little tendency to dissolve or leach contaminants into nonaqueous liquids. The polyamide tubes may be used in preparing samples for analytical procedures such as GC, GC/MS, LC or LC/MS.
G01N 1/18 - Devices for withdrawing samples in the liquid or fluent state with provision for splitting samples into portions
B01D 24/00 - Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
A transmit/receive switch of a nuclear magnetic resonance apparatus includes receive-path and transmit- path superconductors, which are selectively quenched to switch the connection of an NMR radio-frequency coil between transmit and receive circuits. In the transmit state, the transmit- path superconductor is in a superconducting state while the receive-path superconductor is quenched, to isolate a receive-path amplifier from the relatively higher powers of the NMR pulses applied to the sample by the ' transmit circuit. In the receive state, the receive-path superconductor is in a superconducting state while the transmit-path superconductor is quenched. A DC power source is used to supply supercritical current to the superconductors to quench the superconductors.
Articles of manufacture and devices and methods of forming and using the same are provided, wherein the article comprises a porous inorganic substrate contained in or bounded by a support made from an inorganic material are provided, wherein said porous substrate and support are heated to a temperature effective to shrink the support onto the porous substrate such that liquid tight contact is formed between the porous substrate and the support. In a preferred aspect, the porous inorganic substrate has a porosity of at least 5%, and is a porous monolith formed using a sol-gel method. The articles thus formed provide a confined fluid flow through the porous substrate, providing superior performance in separations, catalysis, filtration, and the like.
In a method for exciting a precursor ion in an ion trap (102), the ion is trapped in a nonlinear trapping field that includes a quadrupolar field and a multipole field (506, 510). The quadrupolar field is generated by applying a radio-frequency (RF) trapping voltage to the ion trap at a trapping amplitude and trapping frequency. A supplemental alternating-current (AC) voltage is applied to the ion trap at a supplemental amplitude and supplemental frequency (514). The supplemental amplitude is low enough to prevent ejection of the ion from the ion trap, and the supplemental frequency differs from the secular frequency of the ion by an offset amount. One or more operating parameters of the ion trap are adjusted, such that the ion absorbs energy from the supplemental field sufficient to undergo collision-induced dissociation (CID) without being in resonance with the supplemental field.
A leak detector includes a leak detector inlet to receive a test gas, a vacuum pump coupled to the leak detector inlet, a test gas sensing unit connected through a passage to the leak detector inlet, to sense the test gas, a membrane that is permeable to the test gas, the membrane disposed in the passage between the leak detector inlet and the test gas sensing unit, and a control mechanism to substantially terminate transmission of the test gas through the membrane in a time of 500 milliseconds or less. In other embodiments, the control mechanism substantially terminates transmission of the test gas through the membrane in a time of 100 milliseconds or less.
G01N 27/12 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluidInvestigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon reaction with a fluid
G01N 27/00 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
29.
TEST GAS LEAK DETECTION USING A COMPOSITE MEMBRANE
A leak detector includes a leak detector inlet to receive a test gas; a vacuum pump coupled to the leak detector inlet; a test gas sensing unit connected through a passage to the leak detector inlet; and a membrane that is permeable to the test gas disposed in the passage between the leak detector inlet and the test gas sensing unit, the membrane having a permeance to the test gas that varies by less than five percent over a temperature range of T0-20K to T0 +20K, where T0 is a design temperature. In addition, methods are provided for making a composite membrane that includes a semi-permeable membrane and a porous membrane. Furthermore, a reference leak, which includes a composite membrane is provided.
G01N 27/12 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluidInvestigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon reaction with a fluid
G01N 27/00 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
The vacuum properties of a cryogenic NMR probe maintained at a desired operating temperature by a cold head heat exchanger are improved by a separate heat exchanger operating below the temperature of the cold head heat exchanger for maintaining cryo-pumping surfaces at a temperature below said selected operating temperature.
An apparatus to perform a chromatography process includes a fraction collection system with a rack adapted to support at least one receptacle and a reader coupled to the fraction collection system. The reader is operable to detect a first identification coupled to the rack. The apparatus also includes a chromatography system connected to the fraction collection system to supply a fraction to the receptacle, and a RFED system. The RFID system communicates with the reader and generates data identifying a first location of the receptacle with respect to the rack and a second location of the rack with respect to the fraction collection system.
An automated MicroSampling dissolution testing system that is constructed of a base; a plurality of vessels mounted on an invertible, temperature controlled bath manifold; a cleaning manifold; a stirring and sampling assembly for each vessel; an integrated image capture device, a plurality of hydrodynamic, nonresident sampling probes; a non-resident dispensing manifold; a novel fluid handling system; a MicroSampler; a sample transfer mechanism; and a sample and filter storage apparatus.
The thermal performance and vacuum properties of a cryogenic NMR probe are improved when thermal control is implemented by conductive heat transfer to a cold head cooled by a heat exchanger (78) to below the selected operating temperature. The heat load is manipulated by locating a heater (88) to produce a more nearly constant heat load in conjunction with pulsed RF power and in one embodiment transferring such heater power through a common thermal path. In another embodiment, the heater power is conductively transferred directly to the heat exchanger (78).
RF electric fields produced by electric potential differences in the NMR probe coil windings may penetrate the NMR sample and sample tube causing sensitivity loss and increased noise in NMR spectroscopy. Electrically conducting strips in close proximity to the windings of the NMR probe coil and oriented at right angles to direction of the coil winding they cross provide an alternative path for these electric fields while causing negligible effect upon the RF magnetic field, thereby increasing the sensitivity of the NMR probe.
G01R 33/28 - Details of apparatus provided for in groups
G01R 33/32 - Excitation or detection systems, e.g. using radiofrequency signals
G01R 33/24 - Arrangements or instruments for measuring magnetic variables involving magnetic resonance for measuring direction or magnitude of magnetic fields or magnetic flux
A composition for use in chromatography is provided comprising a substrate modified with a metal-cyano bonded phase. This novel cyano bonded phase provides superior performance in high performance liquid chromatography (HPLC) and provides superior selectivity, improved peak shape for basic analytes, and the ability of provide rapid separation with outstanding resolution. The composition exhibits improved storage stability, and is chemically stable over a range of pH from 1.5 to 7.5 mobile phase conditions and for more than 2000 multiple injections. A baseline separation of eight tricyclic antidepressants was achieved in less than four minutes using an isocratic mobile phase with the metal-cyano bonded phase of the present invention, compared to the long retention times and poor separation observed for traditional cyano bonded phase. The composition of this invention is particularly useful in a wide variety of chromatographic applications.
B01J 20/28 - Solid sorbent compositions or filter aid compositionsSorbents for chromatographyProcesses for preparing, regenerating or reactivating thereof characterised by their form or physical properties
A pair of conductors, spaced apart on the same first surface, form stators of a pair of series connected capacitors in combination with a floating moveable conductor disposed on a parallel second surface with a dielectric in the space between first and second surfaces. The floating conductor has sufficient area to occupy the projection of the stators on the second surface. As the moveable conductor is displaced toward one of the stators and away form the other, the capacitance diminishes until the series circuit is interrupted.
H01G 5/14 - Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaftProcesses of their manufacture using variation of effective area of electrode due to longitudinal movement of electrodes
H01G 5/16 - Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaftProcesses of their manufacture using variation of distance between electrodes
G01R 33/36 - Electrical details, e.g. matching or coupling of the coil to the receiver
G01V 3/00 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation
A single RF port, multiply-resonant circuit comprises coupled resonant sub-circuits coupled through an adjustable reactive element exhibiting a dynamic range that includes a value of the reactive component of sufficient magnitude to produce an impedance producing substantial mutual isolation of the sub-circuits.
G01R 33/32 - Excitation or detection systems, e.g. using radiofrequency signals
A61B 5/055 - Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fieldsMeasuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
According to one aspect, a magnetic resonance (NMR or MRI) phantom includes a spherical or quasi-spherical casing enclosing an internal chamber, and an internal phantom structure situated within the internal chamber. The casing includes alignment features allowing the sequential alignment/orientation of the phantom along three orthogonal axes. In some embodiments, the casing is shaped as a quasi-spherical intercyl having an outer surface defined by the intersection of three orthogonal cylinders. In some embodiments, the casing may be shaped as a sphere having orthogonal registration holes or channels sized to accommodate a corresponding protrusion or ridge in a phantom holder; the casing may also include protrusions or ridges sized to fit into a matching hole or channel defined in a holder. One or more internal phantom plates may include air bubble transfer apertures allowing air bubbles to flow between opposite sides of a plate as a liquid-filled phantom is rotated.
Trace gas leak detectors and methods for trace gas leak detection of large leaks at relatively high test pressures are provided. A trace gas leak detector includes a test port to receive a sample containing a trace gas, the test port connected to a test line, a mass spectrometer to detect the trace gas, a high vacuum pump having an inlet port coupled to the inlet of the mass spectrometer, and a forepump having a main inlet, at least one intermediate inlet and an exhaust. The main inlet of the forepump is coupled to the exhaust port of the high vacuum pump. The intermediate inlet is controllably connected to the test line. The forepump is selected from the group consisting of a scroll vacuum pump and a screw vacuum pump.
G01M 3/20 - Investigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
40.
HIGH SENSITIVITY SLITLESS ION SOURCE MASS SPECTROMETER FOR TRACE GAS LEAK DETECTION
A mass spectrometer includes a main magnet having spaced-apart polepieces which define a gap, the main magnet producing a magnetic field in the gap, an ion source to generate ions and to accelerate the ions into the magnetic field in the gap, the ion source located outside the gap, and an ion detector to detect a selected species of the ions generated by the ion source and deflected by the magnetic field. The ion detector is located in the gap at a natural focus point of the selected species of ions. The mass spectrometer may be used in a trace gas leak detector.
Mass spectrometers for trace gas leak detection and methods for operating mass spectrometers are provided. The mass spectrometer includes an ion source to ionize trace gases, such as helium, a magnet to deflect the ions and a detector to detect the deflected ions. The ion source includes an electron source, such a filament. The method includes operating the electron source at an electron accelerating potential relative to an ionization chamber sufficient to ionize the trace gas but insufficient to form undesired ions, such as triply charged carbon.
patents