Abstract: An oil mechanical vacuum pump, which is equipped with an electric motor comprises an electronic control device for supplying the electric motor with power. The electronic control device comprises a frequency converter for controlling the excitation frequency Fecc of the voltage signal SU by which the motor is powered as a function of at least one operating parameter of the pump and of at least one threshold value that can be modified depending on the operating conditions of the pump.

Abstract: 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.

Abstract: A device and a method provide a detection of a presence of a test gas. The device comprises a vacuum chamber connected to a vacuum pump equipped with an electronic power supply unit. At least one portion of the chamber is separated from a surrounding outside environment by a membrane selectively permeable to the test gas. A gas flow from the outside environment is guided forcefully over the surface of the membrane via a flow conveyor, which comprises an inlet duct, a diffuser and an outlet duct. The presence of any test gas is detected by the changes in the electrical current to the vacuum pump provided by the power supply.

Abstract: 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.

Abstract: Ultraporous sol gel monoliths and methods for preparing the same are provided, having superior flow characteristics for chromatography and analytical chemistry applications. The methods for forming an ultra porous sol-gel monolith include (a) forming a solution comprising a porogen, a matrix dissolving catalyst and a sol gel precursor; (b) allowing the solution to form a gel; and (c) drying the gel at an elevated temperature. The ultraporous sol gel monoliths are characterized by a porosity of up to about 97%, a BET surface area of at least about 50 m2/g and substantially no micropores.

Abstract: An oil rotary vacuum pump of mechanical type (100) is filled with a requested amount of oil at the end of the manufacturing process, then it is stored and then shipped to the user, letting the user to avoid an operation of introducing the proper amount of oil into the pump. The oil leakage is prevented by securing the suction and/or exhaust ports (3, 17) of the pump, which are sealed by means of a removable sealing member, for instance by means of a membrane (21, 23).

Abstract: 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.

Abstract: An improved evaporative light scattering detector apparatus for volatile samples is provided. Conventionally incomplete evaporation of the mobile phase (solvent) cannot be achieved for volatile samples as solvent cannot be fully removed at low temperature because the vapor becomes saturated. At higher temperatures the samples evaporate without forming an aerosol. By adding a dry evaporator gas to the sample before entering a drift tube avoids saturation of the vapor and permits complete evaporation of the solvent at low temperatures.

Abstract: A calibrated spectroscopy instrument and a method for calibrating a spectroscopy instrument are disclosed. The spectroscopy instrument includes a monochromator having a drive mechanism comprising a pair of spur gears for rotating a diffraction grating of the monochromator for selecting a desired wavelength. The drive mechanism is calibrated to account for eccentricities in the spur gears to provide an accurate conversion between selected angular settings for the drive mechanism and the wavelength of the diffracted light from the monochromator. The drive mechanism comprises a pinion spur gear and a main spur gear which each have an AGMA (American Gear Manufacturers' Association) rating of at least 10, which allows errors due to random tooth to tooth variations to be neglected. A calibration algorithm is derived which is based on the error due to eccentricities in the spur gears following a precise geometric cyclic pattern.

Abstract: The NMR device with a magnet utilizes a composition exhibiting a desired value of magnetic susceptibility, wherein the composition comprises a metal ion selected from the group consisting of Gd+3, Fe+3 and Mn+2 and an amorphous material using a ligand or chelating agent to solubilize the metal ion throughout the amorphous material, wherein the magnetic susceptibility of the composition exhibits a desired value at cryogenic temperatures such as nearly zero susceptibility at temperatures at or below 77 K.

Abstract: 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 this transverse direction is aligned parallel with the RF magnetic field of the saddle coil.

Abstract: A support ring (1) for rolling bearings (11), especially for rolling bearings applied to rotors with very high rotation speed, such as rotors of rotary vacuum pumps, the ring comprising a pair of concentric cylindrical shells (3, 5) connected together by a plurality of oblique radial plates (9), at least one of said shells (3, 5) being circumferentially broken so as to define a plurality of shoes (7), each shoe being connected to at least one of the radial plates (9) in such a manner as to define shoe portions or arcs (A1, A2) of different length, wherein the plates (9) are resilient and allow for the radial displacement of the shoes (7) so as to restrain vibrations of the rotating portion.

Abstract: A spectroscopy system for spectro-chemical analysis of a sample includes a plasma torch (50) for generating a microwave induced plasma (90) as a spectroscopic source. The plasma forming gas is nitrogen which can contain an oxygen impurity. Thus the system includes a nitrogen generator (70) which is preferably supplied with compressed atmospheric air from a compressor (75) for oxygen to be removed from the air by adsorption. The invention allows the use of an on-site nitrogen gas generator and thus gives cost savings because the need to obtain supplies of bottled high purity gas is eliminated.

Abstract: A method and apparatus are provided for optimizing a liquid chromatography/mass spectrometry system for gradient elution. A temperature profile is determined according to which a gas is flowed into an atmospheric pressure ionization interface for vaporizing a matrix flowed into the interface from a liquid chromatography column. A flow profile is determined according to which the gas is flowed into the interface for preventing entry of the matrix into the mass spectrometer when the matrix does not include an analyte for which detection is desired. The determination of the temperature and flow profiles is based on the characteristics of the matrix as it eludes from column into the interface. A heat control device and a flow control device can be provided for implementing the temperature profile and flow profile, respectively. The heating control device and flow control device can be programmed or controlled by software.

Abstract: 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.

Abstract: The invention relates to a method of preparing spheroid polymer particles having a narrow size distribution by dispersion polymerization. This method comprises the steps of: providing a two-phase system in the form of a dispersion comprising an organic phase of droplets dispersed in an aqueous medium, mixing said organic phase in said aqueous medium under agitation without using a dispersion stabilizing agent to stabilize the dispersion, wherein the organic phase comprises at least a crosslinkable monomer, a polymerization initiator and an organic solvent for said monomer, and allowing the crosslinkable monomers to polymerize, while the two-phase system is agitated.

Abstract: A phase conjugation vectoring (PCV) of signals propagating in telephone cables of twisted pairs provides crosstalk free transmission therethrough. The cable is considered a non-uniform physical media, and criteria for phase conjugation of electromagnetic fields are established. Method and system provide PCV for both asymmetric and symmetric transmission.

Abstract: 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.

Abstract: An electrode for use in a device such as an ion trap has an axial length extending generally in the direction of a central axis from a first axial end to a second axial end, and an inside surface. The inside surface includes a surface profile that is uniform from the first axial end to the second axial end, or at least is uniform for a uniform section length along the axial direction. The electrode may include an elongated surface feature such as a groove that extends for at least the uniform section length. An aperture may communicate with the groove. The electrode may be axially segmented into regions. Gaps between the regions may be oriented at an angle relative to a plane orthogonal to the central axis. The electrode may be one of several electrodes arranged as an electrode structure coaxially disposed about an elongated interior space.

Abstract: A switchable birdcage coil functioning as a transmitter coil and a separate RF surface coil functioning as the receiver coil are utilize in NMR and MRI apparatus. To prevent the switchable birdcage coil from absorbing energy by coupling to the receiver coil or by absorbing power from the RF field produced by the precessing nuclear spins, one or more of the reactive elements of the birdcage coil are switched from a normal reactive impedance state to a high impedance state. The high impedance state is formed by switchably combining the reactive element with a complementary reactive element thereby forming parallel resonant high impedance circuit that is tuned to resonate at the NMR frequency.