A method for on-line monitoring an electrolytic capacitor condition comprising: measuring a voltage ripple across the electrolytic capacitor and the current ripple flowing through the electrolytic capacitor; measuring the temperature of the electrolytic capacitor; emulating the monitored electrolytic capacitor using a capacitor model comprising a capacitor and a solid state adjustable resistor, applying one of the measured ripple to the capacitor model, adjusting the solid state adjustable resistor to minimize the error between an estimated ripple provided by the capacitor model and the other measured ripple not applied to the capacitor model, and estimating an equivalent series resistance of the monitored electrolytic capacitor using value of the solid state adjustable resistor.

Described herein are methods to determine an amount of shale inhibitor in drilling fluids used in wellbore operations. In some cases, methods include receiving a sample of a drilling fluid, removing solids from the sample to produce a solids-free fluid, contacting the solids-free fluid with an anion to produce a precipitate in a test solution, and determining an amount of an amine-based shale inhibitor within the sample by measuring the amount of the precipitate in the test solution.

A device for measuring the flocculation threshold of a colloidal medium, and a method for measuring the flocculation threshold of a colloidal medium by the addition of aliphatic solvent using the device, including the step of determining the flocculation after the addition of the amount of aliphatic solvent necessary for flocculation.

A device for measuring the flocculation threshold of a colloidal medium, and a method for measuring the flocculation threshold of a colloidal medium by the addition of aliphatic solvent using the device, including the step of determining the flocculation after the addition of the amount of aliphatic solvent necessary for flocculation.

Described herein are methods to determine an amount of shale inhibitor in drilling fluids used in wellbore operations. In some cases, methods include receiving a sample of a drilling fluid, removing solids from the sample to produce a solids-free fluid, contacting the solids-free fluid with an anion to produce a precipitate in a test solution, and determining an amount of an amine-based shale inhibitor within the sample by measuring the amount of the precipitate in the test solution.

Example implementations include a sensor device with a superhydrophobic sensor panel having an abraded first planar surface and a second planar surface opposite to the first planar surface, and a metallic heating element adjacent to the second planar surface of the superhydrophobic sensor panel. Example implementations also include a method of detecting a concentration of heavy metal ions in a solution, by separating a target solute of a target microdroplet from the target micropdroplet, identifying a distribution area of at least one heavy metal ion in an image of the target solute, generating a heavy metal ion concentration quantity based on the distribution area, generating a composite image including an indication of the distribution area, and presenting an indication of at least one of the heavy metal ion concentration quantity and the composite heavy metal ion image. Example implementations also include a method of manufacturing a heavy metal ion sensor device, by abrading a first planar surface of a superhydrophobic sensor panel, depositing a metallic layer on a nonconductive substrate, and contacting the metallic layer to a second planar surface of the sensor panel opposite to the first planar surface.

An embodiment provides a method for measuring sulfate in an aqueous sample, including: introducing an aqueous sample containing an amount of sulfate to a barium dye complex, thereby creating a solution; adding a clarifying agent to the solution, thereby causing the solution to be clarified; and measuring the amount of sulfate in the aqueous sample by measuring a change in color of the solution, the change in color caused by the barium dye complex mixing with the sulfate. Other aspects are described and claimed.

An embodiment provides a method for measuring sulfate in an aqueous sample, including: introducing an aqueous sample containing an amount of sulfate to a barium dye complex, thereby creating a solution; adding a clarifying agent to the solution, thereby causing the solution to be clarified; and measuring the amount of sulfate in the aqueous sample by measuring a change in color of the solution, the change in color caused by the barium dye complex mixing with the sulfate. Other aspects are described and claimed.

The present disclosure relates to an apparatus and a method for measuring miscibility in oil using back titration. The apparatus includes: a flocculation solution storage unit; a flow cell including a UV transmitting member; a dissolving agent storage unit; a UV irradiation unit; and a measurement unit, wherein: a flocculation solution is stored in the flocculation solution storage unit; the flocculation solution circulates between the flocculation solution storage unit and the flow cell; the measurement unit measures the UV transmittance of the flocculation solution while the dissolving agent in the dissolving agent storage unit is supplied to the flocculation solution storage unit; the miscibility in the oil is calculated from the amount of dissolving agent supplied and a change in the UV transmittance measured by the measurement unit; and the miscibility is calculated based on a time point when the slope of increase in the UV transmittance changes.

Pyrogallarene chelating and sequestering agents are disclosed. The chelating and sequestering agents may be used in a homogeneous environment or heterogeneous environment. In addition, chromogenic properties may be utilized to assess the chelation or sequestration of certain atoms.