Abstract: 4-pyrrolylpyridine, a novel anion sensor, displays a substantial color loss upon addition of sodium sulfite in aqueous solvents. A variety of anions were tested, including halides, phosphates, sulfates, and hydroxide, but all solutions remained unchanged aside from the sulfite, which displayed bleaching. Described here is a method for which the exact concentration of sulfites in a consumer product can be determined. The test is sensitive over a broad range of sulfites, from 0.84 ppm to over 10,000 ppm, and is accurate with a standard deviation of ±0.01 ppm.

Abstract: 4-pyrrolylpyridine, a novel anion sensor, displays a substantial color loss upon addition of sodium sulfite in aqueous solvents. A variety of anions were tested, including halides, phosphates, sulfates, and hydroxide, but all solutions remained unchanged aside from the sulfite, which displayed bleaching. Described here is a method for which the exact concentration of sulfites in a consumer product can be determined. The test is sensitive over a broad range of sulfites, from 0.84 ppm to over 10,000 ppm, and is accurate with a standard deviation of ±0.01 ppm.

Abstract: A method is provided for taking electrical impedance tomography measurements using multiple electrodes located at selected positions external to a volume of a subject body. Multiple orthogonal or near-orthogonal signals are introduced simultaneously by way of selected different electrodes and resultant predetermined responses (if any) at receiving electrodes are recorded or determined. The signals are encoded using the technique of code division multiplexing and received signals at each receiving electrode are cross-correlated with original signals to determine the contribution of each original signal to a composite received signal. The invention also relates to apparatus suitable for use in applying a method.

Abstract: The invention provides a marker (20). The marker (20) comprises a circuit (22) actuated by a first frequency into conductive status to track position information of an object (40). The circuit (22) of the marker (20) is in a non-conductive status based on the second frequency, and the first frequency is not in the range of the second frequency for measuring the conductivity information of the object (40). The invention further provides a device for measuring conductivity information of the object by generating the first frequency and the second frequency.

Abstract: A magnetic impedance tomography system comprises an excitation system with several excitation coils to generate an excitation magnetic field to induce eddy currents in an examination volume. For example, a solenoid configuration or parallel coils, e.g. in a Helmholtz configuration are employed, Further, a measurement system is provided with several measurement coils to measure the fields generated by the induced eddy currents. The measurement coils are arranged in a volumetric (3D) geometrical arrangement. The individual measurement coils being orientated substantially transverse to the field line of the excitation magnetic field of the excitation coils. A reconstructor receives measurement data from the measurement system and reconstruct an age of an object in the volume of interest from the measurement data.

Abstract: A method is provided for taking electrical impedance tomography measurements using multiple electrodes located at selected positions external to a volume of a subject body. Multiple orthogonal or near-orthogonal signals are introduced simultaneously by way of selected different electrodes and resultant predetermined responses (if any) at receiving electrodes are recorded or determined. The signals are encoded using the technique of code division multiplexing and received signals at each receiving electrode are cross-correlated with original signals to determine the contribution of each original signal to a composite received signal. The invention also relates to apparatus suitable for use in applying a method.