Student Internships/REU at Other Locations
Summer research - IRES 2019: This summer I will be doing research at the Technical University of Liberec in Liberec, Czech Republic. My research project is about nanofibers and the process behind electrospinning them, specifically using AC (alternating current). I currently have two projects that I will be working on. In my personal project I will be making samples of a polymer, PVA (Polyvinyl alcohol), and water. With those samples I will do viscosity and conductivity testing and spin them using the AC spinning method so; I can take images of the collected fibrous sheets, determine their morphologies, and measure their mechanical properties. I will also be collaborating with a graduate student from UAB to work towards understanding the physics behind AC electrospinning.
My project this summer involves a study of the Strain Localization during Slow Strain Rate Testing of Sensitized Al-Mg Alloys. In simpler words, I perform tensile tests on an aluminum alloy and observe its condition in an SEM (Scanning Electron Microscope) to understand the strain localization behavior of the metal. The purpose of this research is to make aluminum stronger, while maintaining it's other desired features (light weight, low cost of production, etc.). Here is a picture of me working on a SEM in the Marcus Inorganic Cleanroom.
This summer I am working at CentralSupélec in Paris, France. My goal is to study the ultrafast optical response of gold nanoparticles by broadband laser spectroscopy. Light incident on a metal nanoparticle causes the conduction electrons to oscillate. Excitation of the nanoparticles at a resonant frequency results in the creation of a strong electromagnetic field. This phenomenon is known as localized surface plasmon resonance (LSPR). Thanks to the properties of LSPR, one can quickly and efficiently inject energy into the nanoparticle system using ultrashort pulses of light. Ultimately, I hope to excite a system of gold nanoparticles to overheat the water within cancer cells and kill them.
Aashish Kaflee is at the University of Virginia this summer: We are setting up a lab for quantum simulation of bosonic and fermionic quantum many-body systems with ultracold atoms in optical lattices using recently developed techniques of quantum gas microscopy. The well-developed methods of laser cooling and atom trapping are at the heart of the experimental system and that is what I have been helping in currently. These methods allow cooling atoms into the quantum regime at a few billionths of a degree above absolute zero, where the particle statistics is dominating. By loading ultracold atoms into optical lattices very clean realizations of a wide variety of condensed matter models are obtained. The fresh and new view on condensed matter model systems provided by ultracold atoms can help to identify the essence of the physics in these systems guiding us to the understanding of real-world quantum materials with competing quantum effects.
Pawan Khanal at the Department of Physics and Biophysics, University of San Diego.
Project: Triggered disassembly and reassembly of actin networks induce rigidity phase transitions. Non-equilibrium soft materials, such as networks of actin proteins, have been intensely investigated over the past decade due to their promise for designing smart materials and understanding cell mechanics. However, current methods are unable to measure the time-dependent mechanics of such systems or map mechanics to the corresponding dynamic macromolecular properties. Here, we present an experimental approach that combines time-resolved optical tweezers microrheology with diffusion-controlled microfluidics (I do the microfluidics part of this project) to measure the time-evolution of microscale mechanical properties of dynamic systems during triggered activity. We use these methods to measure the viscoelastic moduli of entangled and crosslinked actin networks during chemically-triggered depolymerization and re-polymerization of actin filaments. We develop toy mathematical models that couple the time-evolution of filament lengths with rigidity percolation theory to shed light onto the molecular mechanisms underlying the observed mechanical transitions. The models suggest that these two distinct behaviors arise from phase transitions between a rigidly percolated network and a non-rigid regime. Our approach and collective results can inform the general principles underlying the mechanics of a large class of dynamic, non-equilibrium systems and materials of current interest.
I spent this past summer working at the National High Magnetic Field Lab in a materials testing lab with my mentor Robert Walsh. Specifically, I worked on the material properties and characterization of an epoxy that was invented at the lab for use in vacuum impregnating large superconducting magnets. I did extensive testing on the epoxy at cryogenic temperatures and submitted a report that will later be published. A summary of my work can be found online at nationalmaglab.org on the REU class of 2018 page.
I spent my summer as a research student at Auburn university where I worked on computational magnetospheric physics with Dr. J. D. Perez. My work included studying the interaction of solar storms with the earth’s magnetosphere through the analysis of data obtained from NASA’s TWINS (Two Wide-Angle Imaging Neutral-Atom Spectrometers) mission. All the work I did is submitted to the TWINS geomagnetic Storm Catalog and can be accessed here.
My summer project was to analyze photogrammetry data of the Baryon Mapping Experiment radio telescope. The telescope has been built to gather data for spectral lines emitted from 21 cm neutral hydrogen for the purposes of intensity mapping. Since the universe was primarly comprised of neutral hydrogen during the Dark Ages, looking at these wavelengths at high redshifts will give a good map of the large scale structure of the universe during that period. I analyzed pictures of the telescope's dish surface using a photo-processing software. This involved writing code to find position of targets laid on the parabolic dish surface and producing a "best-fit" curve. This would help to confirm the orientation of the telescope; namely the translation, rotation, and focal length. Click here for more information.
Her project focused on the source of electrical resistance in tin oxide single crystals. Tin oxide crystals are being studied for use in transparent electronic components, and the aim of the project was to find the source of resistance and hopefully reverse its effects on the crystals. Electron Paramagnetic Resonance (EPR) and X-ray Photoelectron Spectroscopy (XPS) were two of the main methods used to test for the source of resistance. Victoria earned second place in the poster presentation competition for the Physical and Applied Sciences division.
Elastin-like polypeptides (ELPs) are a class of biopolymers that undergo a reversible phase transition occurring at a transition temperature. Recently, six-armed star polymers have been synthesized with arms composed of ELPs. My goal this summer was to characterize the solution properties of two six-armed ELP star polymers, the G10 and G19. Above their transition temperatures, these proteins aggregate into nanoparticles of different sizes and shapes which have potential for drug delivery. The transition temperatures of the proteins were measured using spectrophotometry for various protein concentrations, salt concentrations, and pH values. The samples were also investigated using light scattering. In particular, dynamic light scattering was used to probe the size of the aggregates above and below the transition temperature.
Physics major Chandler Bernard spent his summer at a Research Experience for Undergraduates (REU) program in the microelectronics-photonics department at the University of Arkansas. His research involved colloidal CdSe quantum dot nanocrystals, which are nanoparticles with their electrons confined quantum mechanically. These quantum dots also exhibit photoluminescence, which is the emission of light through absorption of photons. Due to their tightly controlled emission spectrum, quantum dot devices are in demand for industry for applications in photovoltaics and solar cells, as well as in medicine for imaging. Chandler's research aimed to use photoluminescence spectroscopy to characterize the dependence of photobleaching (the drop in intensity of emitted light due to exposure to laser radiation) as it depends on time and incident laser power density.
As a participant in UAB’s Research Experience for Undergraduates (REU) program, Troy University physics major Chandler Bernard spent the summer characterizing the spectroscopic properties of Transition Metal and Rare-Earth Metal doped ZnSe crystals for use in middle-infrared lasers. Mid-IR lasers are in high demand for medical diagnostics, industry process monitoring, and defense countermeasures. His most notable contribution was his characterization of absorption and transmission of Cr:ZnSe and Fe:ZnSe crystals with respect to increasing temperatures, with applications in tunable mid-IR lasers and the minimization of thermal losses in mid-IR laser cavities.