Abstract: The present invention is directed to a separator for an electrochemical cell comprising a web, the web comprising fibers of a polyimide and a protective region wherein the protective region impedes electrochemical reduction of the polyimide inside the electrochemical cell. The present invention is further directed to a multi-layer article and electrochemical cell containing the separator.

Abstract: The present invention is directed to a separator for an electrochemical cell comprising a web, the web comprising fibers of a polyimide and a protective region wherein the protective region impedes electrochemical reduction of the polyimide inside the electrochemical cell. The present invention is further directed to a multi-layer article and electrochemical cell containing the separator.

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: 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.