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Full-Text Articles in Engineering
Surface Acoustic Wave (Saw)-Based Gas Flow Sensor, Nisar Ahmad
Surface Acoustic Wave (Saw)-Based Gas Flow Sensor, Nisar Ahmad
Dissertations (1934 -)
There has been a growing interest in using SAW devices for sensing various physical parameters such as pressure, acceleration, temperature, and gas. The current research has been undertaken to derive a model of a SAW-based gas flow rate sensor, using the principle of heat transfer with the flow of gas. It consists of a SAW delay line fabricated on a suitable substrate and a thin film heater to heat the SAW device to a suitable temperature above the ambient. The delay line is connected in the feedback loop of an rf-amplifier resulting in a delay line stabilized SAW oscillator. When …
Analysis Of The Detection Of Organophosphate Pesticides In Aqueous Solutions Using Polymer-Coated Single Idt Sensors, Michael J. Mccarthy
Analysis Of The Detection Of Organophosphate Pesticides In Aqueous Solutions Using Polymer-Coated Single Idt Sensors, Michael J. Mccarthy
Master's Theses (2009 -)
The single interdigital transducer (IDT) device was investigated as a micro-chemical sensor for the detection of organophosphates compounds in aqueous solutions. The compounds of interest are: parathion, parathion-methyl, and paraoxon. The polymers used as a partially-selective coating for the direct detection of these compounds are 2,2'-diallylbisphenol A- 1,1,3,3,5,5-hexamethyltrisiloxane (BPA-HMTS) and polyepichlorohydrin (PECH). BPA-HMTS is synthesized here at Marquette University. The measurement of interest for the single IDT is the change radiation resistance. The radiation resistance represents the energy stored in the propagating acoustic wave. As analyte absorbs into the polymer coating, changes in the film's properties will undergo resulting in …