Abstract: A system or method for gas chromatography has a spool member constructed from a base section and a cover plate. The base portion has a base plate section connected to a wall section. The base plate section and the wall section define a hollow cavity for receiving a fluid. The cover plate is attachable to the base section to seal the cavity. A heating device is attached to and maintains thermal contact with an exterior surface of the spool member. Inlet and outlet ports disposed in the cover plate are in fluid communication with the cavity for introducing a fluid coolant source. Thermally conductive tubes are in thermal contact with an exterior surface of the wall section for transferring heat to a fluid column of analyte within the conductive tubes. The spool member is heated with the heating device during a gas chromatography heating cycle.

Abstract: A method of controlling a mechanical testing instrument includes estimating a young's modulus, and applying force during a first time interval then comparing distance measured to expected distance; predicting a distance based on a first slope applying displacement distance and recalculating the slope; providing a corrected force applied for the proper displacement based on measured modulus and correction factor and adjusting into time and distance coherence; applying a force versus time regime interval and predict deformation at the end of the second interval measuring true deformation distance after the next interval; calculating the ‘true’ slope’ based on the extrapolated actual slope; calculating a slope to apply for desired distance; and repeating measurement and correction steps, using the actual slope as the prediction basis. A system for carrying out the method is also disclosed using a data acquisition board.

Abstract: A method for measuring in-situ the viscosity of a fluid within a vessel using an apparatus using a motor driven impeller paddle immersed in the fluid. A chemical or biological agent is added to the fluid. The impeller paddle is rotated and the rotational positions of impeller drive shaft and the paddle are sensed. The rotational speed of the shaft is determined and the deflection angle of the impeller paddle relative to the shaft is determined. The viscosity of the fluid is determined by a computer from a look up table containing deflection angle for fluids of known viscosities. The measurements are periodically repeated for a predetermined number of iterations to determine the change in viscosity caused by reaction of the fluid with the chemical or biological agent and the results are reported to a user.

Abstract: An apparatus for measuring in situ the viscosity of a fluid within a vessel which includes an impeller paddle immersed in the fluid rotated by an electric motor connected to a shaft passing through a wall of the vessel. The impeller paddle is connected to the shaft by a toroidal spring. The electric motor is controlled by a variable voltage power supply controlled by a computer. Sensors are mounted on the impeller paddle and the shaft to sense the rotational positions of each and to generate electronic signals indicative thereof. The electronic signals are processed by signal processing circuitry to determining the deflection angle of the impeller paddle and the results sent to a computer, where the signals are recorded and analyzed to determine the viscosity of the fluid.

Abstract: An improved nucleic acid hybridization assay, relying on particle counting, is provided. Presence and quantity of target nucleic acid is determined by detecting, upon hybridization, signals associated with particle aggregation or coincident signals from particles and reporters.

Abstract: A method for measuring hematocrit is provided. An electrochemically detectable marker is measured before and after the ratio of red cell volume to plasma volume is decreased. The measured concentrations are used in a mathematical formula to determine hematocrit value.

Abstract: A means for measuring either the intrinsic or inherent viscosity of a solute in solution with a solvent which is independent of flow rate and temperature fluctuations. The solution is passed through one capillary tube and the solvent through a second capillary, and the pressure drop across each is measured. Signals corresponding to each pressure drop measurement are fed to an amplification means such as a logarithmic amplifier where they are processed to determine either the intrinsic or inherent viscosity of the solute independent of flow rate and temperature fluctuations. The viscosity measuring means may also be used together with size exclusion chromatrography to determine the molecular weight distribution of polymer materials. It may also be used to measure the relative viscosity of a sample liquid and a reference liquid, and to determine the viscosity of the sample liquid independent of flow rate and temperature fluctuations.

Abstract: A method for measuring hematocrit is provided. An electrochemically detectable marker is measured before and after the ratio of red cell volume to plasma volume is decreased. The measured concentrations are used in a mathematical formula to determine hematocrit value.

Abstract: A means for measuring either the intrinsic or inherent viscosity of a solute in solution with a solvent which is independent of flow rate and temperature fluctuations. The solution is passed through one capillary tube and the solvent through a second capillary, and the pressure drop across each is measured. Signals corresponding to each pressure drop measurement are fed to a logarithmic amplification means where they are processed to determine either the intrinsic or inherent viscosity of the solute independent of flow rate and temperature fluctuations. The viscosity measuring means may also be used together with size exclusion chromatrography to determine the molecular weight distribution of polymer materials. It may also be used to measure the relative viscosity of a sample liquid and a reference liquid, and to determine the viscosity of the sample liquid independent of flow rate and temperature fluctuations.

Abstract: A particle counting apparatus includes a cuvette having a cylindrical bore therethrough and an exterior cylindrical surface the axis of which is perpendicular to the axis of the bore. The apparatus is adapted to detect light scattered from a particle that is small as compared to the wavelength of incident radiation and has an index of refraction close to that of the medium in which it is entrained.

Abstract: A highly sensitive and rapid method for quantitatively assaying analytes in liquid media by directly measuring changes in particle size distribution of reagent particles having analyte insolubilized thereon in a system undergoing antibody-induced aggregation has been developed. The amount of analyte initially present can be determined by measuring the change in the distribution of particle size with time, the concentration of a particular size particle at a given time, the rate of formation of a particular size particle, or the steady-state maximum concentration for a particular size particle.