Abstract: An imaging tube (16) and an apparatus (60) and a method for pre-balancing the imaging tube (16) for use in an imaging system (10) are provided. The imaging tube mass and center of mass are determined. Desired values for the imaging tube mass and imaging tube center of mass are also determined. A mass correction value and a center of mass correction value are calculated in response to the imaging tube mass, the imaging tube center of mass, and the desired values. The imaging tube mass and the imaging tube center of mass are adjusted in response to the mass correction value and the center of mass correction value respectively.

Abstract: Methods and devices for stop flow detection and measurement of radioactivity in liquid samples are provided. In some embodiments, the invention includes precise positioning of fractions within a flow cell detection area. Novel flow cells and methods providing for flushing samples with gas are also provided.

Abstract: A method and apparatus for determining the effectiveness and reaction time of a breaker fluid in breaking a filter cake on the wall of a wellbore penetrating a subterranean formation is disclosed. The method comprises employing an apparatus, such as for example the apparatus of the invention with a filter medium and the capability of applying differential pressure or dynamic conditions to form a filter cake on the filter medium with drilling mud. Breaker fluid is then substituted for the drilling mud, preferably without damage to the filter cake. The quantity of breaker fluid passing across the filter medium under static conditions is monitored over time. An increase in the rate of fluid passing across or through the medium indicates break-up of the filter cake.

Abstract: A sensor for determining the presence of hydrogen and for measuring the amount of hydrogen present in the vicinity of the sensor. The sensor comprises a metal hydride hydrogen-absorbent material AB5 which selectively absorbs hydrogen and expands upon such absorption. This expansion depends on the amount of hydrogen absorbed and the expansion is detected and measured either by measurement of a change in capacitance of the sensor or by the change in tunnel current flowing through the sensor. A method for determining the presence of hydrogen and for measuring the amount of hydrogen present using the metal hydride hydrogen-absorbent material AB5-based sensor.

Abstract: An intra-aortic balloon pump system having a leak detector comprising a processor, a pressure sensor, and optionally a temperature sensor. Gas leaks from the intra-aortic balloon pump system are detected by comparing shuttle gas pressure readings, taken just prior to IAB inflation, with similar thermodynamic histories, i.e. similar equilibrium times.

Abstract: In a method for determining the alcohol concentration in the alcohol/water mixture of fuel cells that are operated with this mixture, in particular for direct methanol fuel cells, the alcohol/water mixture is pumped through a constriction. The differential pressure between the entry to and exit from the constriction and, if appropriate, the flow velocity of the mixture through the constriction are measured, and the alcohol concentration is determined therefrom.

Abstract: A flowmeter for accurately measuring the flowrate of fluids in high pressure chromatography systems. The flowmeter is a porous bed of a material, the porous bed having a porosity in the range of about 0.1 to 0.6 and a pore size in the range of about 50 nm to 1 &mgr;m, disposed between a high pressure pumping means and a chromatography column. The flowmeter is provided with pressure measuring means at both the inlet and outlet of the porous bed for measuring the pressure drop through the porous bed. This flowmeter system provides not only the ability to measure accurately flowrates in the range of &mgr;L/min to nL/min but also to provide a signal that can be used for a servo loop or feedback control system for high pressure pumping systems.

Abstract: A method of compensating a MOS gas sensor is described and which includes using a MOS gas sensor to provide a signal indicative of gas concentration of a target gas in an ambient; providing a signal representative of dew point of the ambient; and modifying the signal from the MOS gas sensor using the signal representative of dew point to simultaneously compensate for the effects of both temperature and relative humidity on the MOS gas sensor.

Abstract: An improved method for detecting leaks in a sealed package or container, where the contents of the container includes at least one liquid component, is disclosed. First the container to be tested is placed in a vacuum chamber which is in turn sealed. A vacuum is then applied to the vacuum chamber to lower the pressure, within the chamber, to a pressure that is below the vapor pressure of the liquid component in the container being tested. The vacuum source is then isolated from the chamber. The presence and severity of any package leak is detected by monitoring the increase of pressure in the vacuum chamber as a leak indicative signal whereby a relatively steady increase in pressure over time is indicative of “leaking” unrelated to the package under test and wherein relatively uneven increases of pressure, over time ,is indicative of boiling liquid and therefore a leak in at least one test specimen.

Abstract: The present invention provides a method for analysing a well completion system, wherein the method includes receiving data representative of physical characteristics of the completion system and calculating a first change in length of a tube string resulting from a helical buckling effect. The method further includes calculating a second change in length of the tube string resulting from a ballooning effect and calculating a third change in length of the tube string resulting from a slackoff force effect. Upon completion of the calculating steps, the method may output predetermined results therefrom.

Abstract: Self-washing injection apparatus [101] for liquid chromatography injection valves utilizes an interior chamber [105] with a penetrable seal [109] at the top end of the chamber and a needle sleeve seal [113] at the bottom end of the interior chamber. A wash port [145] in the body [103] of the apparatus connects one or more sources of wash fluid to the interior chamber between the penetrable seal and the sleeve seal. The apparatus provides a simple and effective means to aspirate or pump wash fluids from one or more wash fluid reservoirs through the apparatus, the injection port of the injection valve, and associated components.

Abstract: An apparatus and method for determining the viscosity of a fluid over plural shear rates caused by a decreasing pressure differential by monitoring the movement of the fluid through a riser tube and a capillary tube. The movement can be monitored by detecting the changing weight of the fluid, using a precision balance or load cell, as it moves through the riser tube and capillary tube into a fluid collector; or, alternatively, the movement can be monitored by detecting the changing level of a fluid column in the riser tube using a column level detector. A processor then uses the changing weight or height data, along with the dimensions of the capillary tube and a dimension of the riser tube, to determine the viscosity of the fluid. In addition, apparatus and methods for determining fluid viscosity online and fluid mixture homogeneity online are also described.

Abstract: The present invention relates to a method of determining the relative proportions of gases in a mixture, such that the relative proportions of N gases are determined using N-1 sensors, not all of which are specific to a particular gas. In the preferred embodiment, oxygen and carbon dioxide are measured in the presence of nitrogen by measuring magnetic susceptibility and speed of sound. The described method of gas analysis leads to very fast response times and exceptional stability, making the technology suitable for breath-by-breath analysis of respired air. Notably, the method does not require high-temperature components, electrochemical cells, or consumable components.

Abstract: This invention relates to a gas sensor arrangement in which one or more gas sensors (4) are placed into rooms for monitoring or measuring gas or vapor concentrations or mixtures, a diffusion body (5) is placed in front of the gas sensors (4), the responsiveness of the gas sensors is impaired by structural design or contamination and/or the gas atmosphere is static. The sensor (4) or sensors (4.1 to 4.n) are placed in, on, or in front of a duct (1) located in the room and thus are within the flow area of said duct (1), and a flow is present in the duct (1) during measuring or monitoring. The duct can be artificially heated using a heater (6) to generate this flow.

Abstract: A method and apparatus for testing seals of packages or containers incorporating gas permeable materials wherein the packages are placed between opposing components of a vacuum test chamber such that the seals of the packages are open to a pressure testing system. A flexible bladder backed by a foam material or pressurized fluid seal the gas permeable material afterwhich at least a partial vacuum is drawn to create pressure differential between interior sealed spaces of the packages and the exterior of the package seals. In some embodiments, flexible bladders are provided to initially seal opposite surfaces of packages having opposite gas permeable material covering layers.

Abstract: A method of determining the shear threshold of a drilling mud consists in placing a detecting head with a spherical surface near to a porous wall, in pouring the drilling mud around the detecting head, in forcing the mud to pass through the porous surface so as to form a mud cake above the porous surface and around the detecting head which has a diameter D, and in measuring both the time required for the mud cake to reach a measurable or pre-determined height, and also the torque opposing rotation of the detecting head corresponding to that height.

Abstract: A method of testing magnetorheological fluid comprises cycling the fluid at an elevated temperature, allowing the fluid to stand, performance testing the fluid, cycling the fluid at superimposed frequencies, and noting settling characteristics of the fluid.

Abstract: A method and apparatus for foaming and then testing the foamed fluid. The apparatus comprises a cylindrical pressure vessel with upper and lower caps. A circular disk with a plurality of openings, which are preferably circular openings, is placed in the pressure vessel. The apparatus also includes a motor with a shaft extending therefrom. The shaft is attached to the pressure vessel so that when the motor is actuated, the pressure vessel can be rotated in a desired revolutions per minute. The method includes placing a mixture in the pressure vessel and then attaching the caps to the upper and lower ends of the vessel. The upper cap has a pressure gauge and has a pressure inlet and a pressure relief valve. The circular disk is placed in the vessel. The vessel is pressurized to a desired pressure with a gas motor. The motor is then actuated to rotate the vessel.

Abstract: An apparatus and method for determining the viscosity of a fluid over plural shear rates caused by a decreasing pressure differential by monitoring the movement of the fluid through a riser tube and a capillary tube. The movement can be monitored by detecting the changing weight of the fluid, using a precision balance or load cell, as it moves through the riser tube and capillary tube into a fluid collector; or, alternatively, the movement can be monitored by detecting the changing level of a fluid column in the riser tube using a column level detector. A processor then uses the changing weight or height data, along with the dimensions of the capillary tube and a dimension of the riser tube, to determine the viscosity of the fluid. In addition, apparatus and methods for determining fluid viscosity online and fluid mixture homogeneity online are also described.

Abstract: A sampling and gas chromatographic separation detection system and method which is capable of sampling and analyzing particulate and vapors containing drug and explosive residues in real time. The system and method provide high speed and low power consumption from the combination of a cold ion mobility spectrometer (IMS) with a “heat-on-demand” gas chromatographic (GC) system which eliminates the need to continuously heat the device, thus making the detection system battery operable and portable.