Teaching

I am always on the lookout for new courses to contribute to the physics curriculum, as well as ways to improve our current offerings. (The motivated and engaged student population at Sarah Lawrence is fortunately a great audience for testing out new teaching techniques!)

After adding more and more interactive engagement activities over the years, I aim to fully ‘flip’ the classroom for my general physics courses this coming academic year. (Much of the content will be presented in online videos outside of class, leaving class time to go over more complex concepts and to do more interactive engagement activities and problem-solving in small groups.) I will also be developing more hands-on, laboratory-based courses for non-science and science majors in the coming year!

My current courses for the 2018-2019 academic year are:

• Introductory Mechanics
• Introductory Electromagnetism
• Time to Tinker (Workshop-style course)

Previous courses:

• It’s About Time (First-Year Seminar)
• Modern Physics
• Chaos

Research

3D Printed Linear Actuator

3D Print designs for a linear actuator to discretely move NMR sample tube.

3D Printing Improved NMR Mandhalas

Information towards creating a strong, homogeneous magnetic field and linear gradient for imaging using a 3D printer and permanent magnets.

Implementing 3D printed gradients for use in low-cost magnetic resonance imaging.

3D Printing NMR Mandhalas

Information on creating NMR Mandhalas for a strong, homogeneous magnetic field using a 3D printer and permanent magnets.

Selected Publications

Phosphorus-31 MRI of hard and soft solids using quadratic echo line-narrowing

Here we demonstrate how to use the quadratic echo pulse sequence to carry out three-dimensional MRI of the phosphorus (31P) in ex vivo bone and soft tissue samples.
Proceedings of the National Academy of Sciences

Accelerating multidimensional NMR and MRI experiments using iterated maps

Here we discuss an approach for reconstructing multidimensional nuclear magnetic resonance (NMR) spectra and MR images from sparsely-sampled time domain data, by way of iterated maps. This method exploits the computational speed of the FFT algorithm and is done in a deterministic way, by reformulating any a priori knowledge or constraints into projections, and then iterating.
Journal of Magnetic Resonance

Recent Posts

RF Probe Building

(Written by Jianlong (Ken) Zhu) RF Probe We designed our own RF probe with the aid of a manual, Experimental Pulse NMR: A Nuts and Bolts Approach (Eiichi Fukushima and Stephen B. W. Roeder). Below are some takeaways from the section “V.C.4. Probes” (p.p. 373-385): A good coil for RF probe has a large inductance, which is given by the equation: $L = \frac{n^2 a^2}{23a+25b}$ μH, where n is the number of loops, and a and b are the radius of the loop and the length of the coil measured in centimeters.

T1 and T2 Plotting

(Written by Nicholas Torres) An important aspect of conducting NMR analysis is finding two time-constants: T1 and T2. The T1 constant represents the longitudinal relaxation time or how long it will take for a proton that has been energized by a radiofrequency (RF) pulse to go back to realign with the magnetic field, whereas the constant T2 or transversal relaxation time tells us roughly how long it will take for a proton that has been struck with a 90° RF pulse to dephase from its neighboring protons due to different local magnetic environments.

Summer Science 2018 Summary

(Written by Jeremiah O’Mahony) This summer, Ken Zhu and Nick Torres joined Jerry O’Mahony to help improve Merideth Frey’s lab at the Sarah Lawrence Summer Science Physics Internship. The bulk of our focus over the summer was split between improving the Halbach Mandhala design from last summer and getting the TeachSpin system up and running. We succeeded in both–the current Mandhala is more powerful and versatile than the last, and as of the last week of the internship, the TeachSpin system is reliably detecting 1-D images of samples.