Methods and techniques are described for analyzing test fluids to determine presence, absence, or concentration of analytes in the test fluids. The methods may correspond to diagnostic testing, such as quickly (within 5 minutes) identifying whether or not an individual may have a particular disease or condition, such as infection by SARS-CoV-2 or a SARS-CoV-2 variant or vaccine-induced immunity or natural immunity to infection by SARS-CoV-2 or a SARS-CoV-2 variant, or whether an individual would benefit from a vaccine booster. The test results can be used for a variety of applications including facilitating or controlling access at events, venues, or transportation systems, or generating exposure notifications.

An apparatus and method wherein the apparatus includes a channel; at least one pair of electrodes provided within sides of the channel; an electrolyte configured to move through the channel such that when the electrolyte is positioned between the at least one pair of electrodes the electrolyte provides a current path between the at least one pair of electrodes; and wherein the at least one pair of electrodes are configured such that movement of the electrolyte through the channel enables a time varying voltage to be provided.

An apparatus and method wherein the apparatus includes a channel; at least one pair of electrodes provided within sides of the channel; an electrolyte configured to move through the channel such that when the electrolyte is positioned between the at least one pair of electrodes the electrolyte provides a current path between the at least one pair of electrodes; and wherein the at least one pair of electrodes are configured such that movement of the electrolyte through the channel enables a time varying voltage to be provided.

An electronic integrated multi-electrode detection system of a potential determination includes a multi-electrode array, a circuit unit and a total signal output and acquisition unit. The circuit unit includes a multi-electrode array signal input end, a high input impedance voltage follower, a phase shifting filter circuit, an extension module input end, a summing circuit and a total output signal end. The detection system promotes the detection sensitivity and increase the accuracy and precision of detection results. The detection system can be used for monitoring the change in trace ion concentration in a sample, analyzing a constant conventional sample and analyzing a sample with higher error requirement. The detection system can be widely applied to various analysis detection fields, including life sciences, environmental sciences, medicine clinics, and the like.

A method of in vivo conditioning of an indwelling sensor to reduce run-in time, (stabilization time) comprising: a) applying a first potential to the sensor and measuring a first current at the first potential; b) applying a second potential to the sensor and measuring a second current at the second potential; c) determining a relationship of the first current measured to the second current measured; repeating a, b, and c until the relationship between the first current measured and the second current measured has stabilized, thereby reducing sensor run-in time.

A method of in vivo conditioning of an indwelling sensor to reduce run-in time, (stabilization time) comprising: a) applying a first potential to the sensor and measuring a first current at the first potential; b) applying a second potential to the sensor and measuring a second current at the second potential; c) determining a relationship of the first current measured to the second current measured; repeating a, b, and c until the relationship between the first current measured and the second current measured has stabilized, thereby reducing sensor run-in time.

Disclosed is a design reference value quantification method for a modifier dosage of modified asphalt. A curve of unsaturation degree of the modified asphalt as a function of the modifier dosage is plotted, in which the unsaturation degree of a series of modified asphalts is determined by potentiometric titration; further, an inflection point of the unsaturation degree of the modified asphalt as a function of the modifier dosage in the asphalt is obtained by data fitting and analysis, and a reference value of the dosage of the modifier added in the process design of the modified asphalt is established.

Disclosed is a design reference value quantification method for a modifier dosage of modified asphalt. A curve of unsaturation degree of the modified asphalt as a function of the modifier dosage is plotted, in which the unsaturation degree of a series of modified asphalts is determined by potentiometric titration; further, an inflection point of the unsaturation degree of the modified asphalt as a function of the modifier dosage in the asphalt is obtained by data fitting and analysis, and a reference value of the dosage of the modifier added in the process design of the modified asphalt is established.

Apparatus comprise an electrode arrangement comprising a plurality of electrodes defining a volume, an ion entrance, and an ion exit, and a voltage source coupled to the plurality of electrodes and configured to apply a nonlinear DC voltage sequence to the electrodes between the ion entrance and the ion exit that directs ions through the volume with the volume at a pressure of at least 1 Torr. Ions can be focused using nonlinear DC voltage sequences, including at atmospheric pressure. Related methods are also disclosed.

Apparatus comprise an electrode arrangement comprising a plurality of electrodes defining a volume, an ion entrance, and an ion exit, and a voltage source coupled to the plurality of electrodes and configured to apply a nonlinear DC voltage sequence to the electrodes between the ion entrance and the ion exit that directs ions through the volume with the volume at a pressure of at least 1 Torr. Ions can be focused using nonlinear DC voltage sequences, including at atmospheric pressure. Related methods are also disclosed.