Abstract: A visual perception of a colored site in an immunoassay device comprising a strip for enabling capillary migration of a fluid sample therealong, a labeled reagent disposed on the strip and formulated for suspension in the sample migrating therepast and a captive reagent immobilized on the strip in a path of sample migration and formulated to bind to is enhanced by changing a color of the strip to the color which is complimentary to the colored site.

Abstract: In a method for inhibiting space charge-related effects in an ion source, an electron beam is directed into a chamber to produce ions from sample material in the chamber. A voltage pulse is applied to the chamber to perturb an electron space charge present in the chamber. The ion source may be an electron impact ionization (EI) apparatus. The ion source may operated in conjunction with a mass spectrometry system.

Abstract: Methods and apparatus are provided for leak detection by the accumulation method. The apparatus includes a sealable chamber (10) configured to receive a test piece (12) that, while in the chamber, contains a trace gas, a trace gas permeable member (30) in gas communication with the chamber, and a trace gas sensor (20) in gas communication with the permeable member and configured to sense the trace gas that passed from the chamber through the permeable member. The permeable member may be quartz. The trace gas sensor may include an ion pump.

Abstract: 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 to below the selected operating temperature. The heat load is manipulated by locating a heater 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.

Abstract: A fluid collection and testing device includes a collection vial having a bottom and an open top along with an expresser sized for insertion into the vial open end. The expresser includes a ribbed base enabling fluid to pass therethrough and a support member holds the expresser within the collection vial with the ribbed base in a spaced apart relationship with the vial bottom. A fluid collector includes an absorbent member capturing a fluid and the absorbent member is sized for insertion into the expresser and is compressible against the ribbed base for releasing captured fluid through the ribbed base and into the vial bottom. A catch mechanism is provided for latching the fluid collector to the expresser after insertion into the expresser for enabling simultaneous removal of the expresser and the fluid collector from the collection vial.

Abstract: A sample container may include an open end, a closure member, a cap, and an RFID tag. The RFID tag may be positioned near the open end and includes a code uniquely identifying an analytical sample contained in the container structure. A sample handling apparatus may operate with one or more sample containers. The sample handling apparatus may include a robotic assembly for moving a sample probe device and a sample probe supported by a guide of the sample probe device. An RF transceiver antenna may be mounted to the guide for communicating with the RFID tag of the sample container. The sample probe device is moved into proximity with a sample container to read a code stored by an RFID tag attached to the sample container, whereby a sample contained in the sample container can be uniquely identified. The code can be associated with additional information relating to the identified sample.

Abstract: Scroll pumping apparatus includes a first scroll element and a second scroll element, a drive mechanism operatively coupled to the second scroll element for producing orbiting motion of the second scroll element relative to the first scroll element, and a synchronization device including a strip having connected, substantially flat sections, coupled between the first scroll element and the second scroll element. The synchronization device may have a generally square configuration.

Abstract: Vacuum pumping apparatus includes a pump frame, a stationary scroll element secured to the pump frame, the stationary scroll element including a stationary scroll blade, an orbiting scroll element including an orbiting scroll blade intermeshed with the stationary scroll blade, a motor secured to the pump frame, and a crankshaft coupled between the motor and the orbiting scroll element for producing orbiting movement of the orbiting scroll blade relative to the stationary scroll blade when the motor is energized. The crankshaft includes a first component having a first coefficient of thermal expansion and a second component having a second coefficient of thermal expansion.

Abstract: In some embodiments, a tandem (MS/MS) mass spectrometry method includes selecting a collision-induced dissociation (CID) voltage amplitude and a q-parameter value for a quadrupole ion trap to optimize a daughter ion fragmentation process for a given parent ion mass-to-charge (m/z) ratio. The q and CID voltage values may be selected according to a look-up table and/or using approximate analytical expressions. The correspondence between m/z values and (q, CID) value pairs may be established by pre-measurement calibration. A fragmentation-optimized q value may be computed according to m/z, and a CID voltage value may be determined according to the computed q value. A user may also force q to another value, for example in order to facilitate trapping of a desired daughter ion mass range, and the controller computes a CID voltage value according to the forced q value.

Abstract: A molecular drag compressor includes a rotor disk coupled to a drive shaft for rotation about an axis, a stator disposed about the rotor disk, the stator defining a tangential flow channel, an inlet to the tangential flow channel and an outlet from the tangential flow channel, and a stationary baffle disposed in the tangential flow channel adjacent to the outlet. The baffle and the rotor disk have a gap between them. A surface of the baffle facing the rotor disk has cavities configured to produce turbulent gas flow through the gap between the baffle and the rotor disk and to thereby reduce leakage.

Abstract: Methods and apparatus for large leak testing are provided. The apparatus includes a test line to receive a sample containing a trace gas, a mass spectrometer to detect the trace gas and having an inlet for receiving the trace gas, a first vacuum pump characterized by a relatively high reverse flow rate for light gases and a relatively low reverse flow rate for heavy gases, the first vacuum pump having a pump inlet and a foreline, the pump inlet being coupled to the inlet of the mass spectrometer, and a second vacuum pump configured to back the first vacuum pump. The apparatus further includes a trace gas permeable member coupled between the test line and the pump inlet, the foreline, or, in the case where the first vacuum pump is a turbomolecular pump, a midstage line.

Abstract: Enhanced nuclear polarization of a magnetic resonance sample provides greater detection sensitivity over conventional NMR spectroscopy due to a method and an apparatus of increasing the detection sensitivity. Molecules capable of forming photo-excited triplet states are combined in a solution with a NMR sample. While in a uniform magnetic field the solution is frozen, optical radiation is applied to produce photo-excited triplet states molecules and a microwave radiation is applied to stimulate transitions of one of the triplet lines producing dynamic polarization of the nuclei in the magnetic resonance sample. The frozen sample is then rapidly melted and a NMR analysis is performed.

Abstract: The gate valve includes a valve housing (12) having a fluid conduit (14) and defining a valve seat (16) and a support surface (18), a seal plate (20), a counter plate (22) having cushion (72) vulcanized to a surface facing the support surface (18), and an actuator (34) for moving the seal plate and the counter plate between respective open and closed positions. The cushion is configured to prevent metal-to-metal contact between the counter plate and the support surface of the valve housing.

Abstract: A vacuum pumping system includes a primary vacuum pump having an inlet for coupling to a system, and a secondary vacuum pump having an inlet coupled to the exhaust of the primary vacuum pump. The primary vacuum pump is an oil-free, positive displacement vacuum pump having multiple clearance seals between the inlet and the exhaust. The primary vacuum pump may be a scroll vacuum pump, and the secondary vacuum pump may be an oil-free diaphragm pump. The system may include a valve coupled to the exhaust of the primary vacuum pump and configured to couple the exhaust of the primary vacuum pump to an interpump exhaust in response to a selected condition, such as the pressure level at the exhaust of the primary vacuum pump.

Abstract: An apparatus for selectively coupling fiber optic lines comprises an optical input selection device, an optical output selection device, and a rotatable coupling mechanism interconnecting the optical input selection device and the optical output selection device. The optical input selection device is rotatable about a first central axis, and comprises a first input end and a first output end. The first input end is disposed collinearly with the first central axis, and the first output end is disposed at a radially offset distance from the first central axis. The optical output selection device is rotatable about a second central axis, and comprises a second input end and a second output end. The second input end is disposed at a radially offset distance from the second central axis, and the second output end is disposed collinearly with the second central axis. Rotation of the coupling mechanism causes rotation of the first output end and the second input end.

Abstract: An apparatus for use in atmospheric pressure ionization includes a sample receiving chamber, a sample droplet source communicating with the sample receiving chamber, an outlet conduit, and a boundary. The outlet conduit defines a sampling orifice that communicates with the sample receiving chamber. The boundary is interposed between the sample receiving chamber and the sampling orifice and comprises an opening. The opening defines a first passage through which a drying gas is flowable into the sample receiving chamber in an elongated flow profile, and a second passage through which sample material is flowable from the sample receiving chamber toward the sampling orifice. The first passage is positioned in non-coaxial relation to the second passage. The first passage is configured to introduce the elongated flow profile of the drying gas into a pathway of droplets of the sample material flowing toward the second passage.

Abstract: According to one aspect, the low-frequency (e.g. lock channel) performance of a nuclear magnetic resonance (NMR) saddle-shaped, distributed-capacitance radio-frequency (RF) coil is improved by connecting a pair of auxiliary inductors across a plurality of leads extending upward from the coil upper ring. The upward-extending leads can be formed from the same foil as a main coil structure. The auxiliary inductors are separated from the coil window, so that magnetic susceptibility discontinuities introduced by the auxiliary inductors can be compensated for. In one embodiment, two half-toroid auxiliary inductors are positioned to form a full toroid shape. Some lost high-frequency performance can be recovered by using a split capacitance band positioned over the lower coil ring. The split capacitance band allows capacitance tuning while maintaining an RF current path close to the coil window.

Abstract: Novel compositions are disclosed for use as a stationary phase in chromatography comprising an inorganic substrate that is modified with at least one silane having the formula R1?-Q?-(CH2)?SiR2?X3-?. In a preferred embodiment, the inorganic substrate is silica gel and is modified with at least two silanes. Methods of preparation and use in chromatographic applications are disclosed. The novel compositions provide superior chromatographic performance, reduced silanol activity, enhanced stability, and reproducibility in preparation and performance.

Abstract: Halogenated polymers of vinyl aromatic monomers comprising styrene and divinylbenzene are provided for use in a chromatographic separation method of analytes, wherein said polymer further comprises a hydrocarbyl or halocarbyl substituent comprising from 1 to 1,000,000 carbon atoms, or combinations thereof. Methods of using the halogenated polymers are also provided. The polymers and methods are particularly useful in the separation of nucleic acids labeled with hydrophobic labels such as protecting groups, fluorophores, and the like.

Abstract: In some embodiments, a nuclear magnetic resonance (NMR) sample container having an elongated transverse cross-section is held in a predetermined azimuthal orientation in an NMR probe by keying-in a sample container holder into a matching azimuthal-alignment adapter. The azimuthal-alignment adapter may be a lead-in adapter having an azimuthally-sloping upper guiding surface of a cylindrical shell part, with the sloping guiding surface leading into a longitudinal channel defined through the shell wall. A transversely-protruding pin of the sample container holder slides down the guiding surface and into the longitudinal channel to lock the sample in the desired azimuthal orientation.