395 shared publications
Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario M5S3H6, Canada
149 shared publications
Nottingham Trent University, School of Science and Technology, Clifton Lane, Clifton, Nottingham, NG11 8NS, UK
23 shared publications
Advanced Textiles Research Group, School of Art & Design, Nottingham Trent University, Bonington Building, Dryden Street, Nottingham NG1 4GG, UK
3 shared publications
School of Science and Technology; Nottingham Trent University; Clifton Campus, Clifton Lane Nottingham UK NG11 8NS
(2015 - 2018)
Magnetic resonance relaxometry, conducted by field cycling, has become an increasingly popular technique in recent years. In particular, it has the ability to monitor biomass transformation which is of particular interest to wastewater treatment. Traditional field cycling often uses expensive and large electromagnets. In this work we present a small, portable field cycling sensor which can detect changes in biomass in constructed wetland samples.
Fast field cycling is a technique that uses a varying magnetic field applied to a sample, polarising it at a high field, allowing it time to develop at a lower field and then collecting the data at the same initial high field. This change in T1 can reveal interesting properties of the samples not achievable by traditional methods.
A desktop magnetic resonance sensor that undertakes relaxometry measurements using field cycling has been developed using a combination of permanent magnets and electrical coils which has been used to test a range of samples. We demonstrate the effectiveness of this sensor by conducting measurements of T1 at different field strengths for wetland samples at different stages of biofilm growth.
The control electronics for low field pulsed NMR systems, commonly referred to as the console, are designed to be wide band and highly programmable. The process of making spin lattice relaxation time (T1) measurements with such a pulsed system usually use recovery sequences that will typically take many minutes to give a single T1 value. A simple transient effect method for the determination of the spin-lattice relaxation time using continuous wave NMR with a marginal oscillator, known as TEDSpiL, was recently reported (doi:10.1002/mrc.4594). Such a system measures a parameter, called Tx, that is related to T1 and allows T1 to be determined with the aid of calibration samples. For such a system, the process of making the Tx measurement only takes a few seconds and does not require variable parameters so is ideal for implementing in microcontroller code. In this presentation, we demonstrate that TEDSpiL may be automated using two microcontrollers from the Teensy family. One microcontroller is used to generate a magnetic field sweep voltage and a trigger pulse for the second microcontroller that is used to record the data and calculate the value of Tx. Whilst the Tx value is not a direct equivalent for T1, there are applications where such a method may provide a suitable cost effective, low power and portable measurement technique.