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Full-Text Articles in Chemical Engineering

Tailoring Thermoresponsive Poly(N-Isopropylacrylamide) Toward Sensing Perfluoroalkyl Acids, Dustin Thomas Savage Jan 2021

Tailoring Thermoresponsive Poly(N-Isopropylacrylamide) Toward Sensing Perfluoroalkyl Acids, Dustin Thomas Savage

Theses and Dissertations--Chemical and Materials Engineering

Widespread distribution of poly- and perfluoroalkyl substances (PFAS) in the environment combined with concerns for their potentially negative health effects has motivated regulators to establish strict standards for their surveillance. The United States Environmental Protection Agency issued a cumulative domestic threshold of 70 ppt for water supplies, and this bar is even lower in some local districts and other countries. Monitoring PFAS consequently requires sensitive analytical equipment to meet regulatory specifications, and liquid chromatography with tandem mass spectroscopy (LC/MS/MS) is the most common technique used to satisfy these requirements. Though extremely sensitive, the instrument is often burdened by pretreatment regimens, …


Temperature, Stress, And Corrosive Sensing Apparatus Utilizing Harmonic Response Of Magnetically Soft Sensor Element (S), Craig A. Grimes, Keat Ghee Ong Oct 2003

Temperature, Stress, And Corrosive Sensing Apparatus Utilizing Harmonic Response Of Magnetically Soft Sensor Element (S), Craig A. Grimes, Keat Ghee Ong

Chemical and Materials Engineering Faculty Patents

A temperature sensing apparatus including a sensor element made of a magnetically soft material operatively arranged within a first and second time-varying interrogation magnetic field, the first time-varying magnetic field being generated at a frequency higher than that for the second magnetic field. A receiver, remote from the sensor element, is engaged to measure intensity of electromagnetic emissions from the sensor element to identify a relative maximum amplitude value for each of a plurality of higher-order harmonic frequency amplitudes so measured. A unit then determines a value for temperature (or other parameter of interst) using the relative maximum harmonic amplitude …


Magnetoelastic Sensing Apparatus And Method For Remote Pressure Query Of An Environment, Craig A. Grimes, Plamen G. Stoyanov, Dimitris Kouzoudis May 2002

Magnetoelastic Sensing Apparatus And Method For Remote Pressure Query Of An Environment, Craig A. Grimes, Plamen G. Stoyanov, Dimitris Kouzoudis

Chemical and Materials Engineering Faculty Patents

A pressure sensing apparatus for operative arrangement within an environment, having: a sensor comprising a hermetically-sealed receptacle, at least one side of which has an flexible membrane to which a magnetically hard element is attached. Enclosed within the receptacle is a magnetostrictive element that vibrates in response to a time-varying magnetic field. Also included is a receiver to measure a plurality of successive values for magneto-elastic emission intensity of the sensor taken over an operating range of successive interrogation frequencies to identify a resonant frequency value for the sensor. Additional features include: (a) the magnetically hard element may be adhered …


Remote Resonant-Circuit Analyte Sensing Apparatus With Sensing Structure And Associated Method Of Sensing, Craig A. Grimes Mar 2002

Remote Resonant-Circuit Analyte Sensing Apparatus With Sensing Structure And Associated Method Of Sensing, Craig A. Grimes

Chemical and Materials Engineering Faculty Patents

A resonant sensing apparatus for operative arrangement within a test environment to sense an analyte. A sensing structure is included having an antenna in electrical communication with a resonant circuit and a structural element made of a material that selectively responds to the analyte. This sensing structure will resonate at a particular characteristic resonant frequency in the presence of an applied interrogation electromagnetic field and the analyte upon the occurrence of the selective response. A receiver is used for remotely identifying a value for the characteristic resonant frequency by measuring a plurality of values for electromagnetic emission intensity of the …