Archive: CAP REU Project Offerings, 2012
Projects with Prof. Kannappan (observational astrophysics)
Project with Prof. Miller (biophysical fluid mechanics)
Project with Prof. Oldenburg (biomedical optics)
Project with Prof. Superfine (experimental biophysics)
Project with Prof. Washburn (nanophysics)
Projects with Prof. Wilkerson (experimental nuclear & particle astrophysics)
Projects with Prof. Kannappan (2 of the 3 below).
The Origin of Gas for Galaxy Disk Building.
Understanding how galaxies obtain their gas is a crucial ingredient in our knowledge of galaxy evolution. We aim to investigate the origin of the gas in galaxies in the first stages of disk building, with signs of recent arrival of fresh gas that has not yet formed stars. To determine whether this gas represents freshly accreted pristine gas or the recycled gas from outflows due to recent star formation, the student will analyze newly obtained deep optical spectroscopy of galaxies in the early stages of disk building. The student will use the IDL data analysis environment to write a Gaussian/Voigt profile fitting program that will extract emission/absorption line fluxes to measure stellar and gas metallicities (heavy element abundances) and Doppler shifts to measure gas velocities. The code will decompose overlapping absorption and emission features and correct for the reddening effect of interstellar dust. Extending this analysis, the student can also align and stack spectra to achieve deeper measurements for subsets of galaxies defined by their masses and/or environments within the RESOLVE Survey, a complete census of galaxies within a huge volume of the nearby Universe. The heavy element abundances and rotation velocities of both the stars and the gas as a function of radius will constrain the origin of the extended gas disks, with lower metallicities and larger velocities signaling the presence of pristine gas falling in from the cosmic environment. (Co-mentored by D. Stark; currently available only by fellowship.)
Star Formation in High Velocity Clouds?
Recent observations have shown that stars can form in the very outer disks of galaxies, an environment previously though impossible for star formation. We aim to explore whether star formation is possible in another region also thought unlikely to harbor it, High Velocity Clouds (HVCs). HVCs are large clouds of atomic gas that appear to be surrounding and falling towards the Milky Way. A student will use 21 cm radio data, far-infrared (FIR) image data, and new deep ultraviolet image data to look for evidence of star formation in one specific HVC, the Smith Cloud, which is currently colliding with the Milky Way, our home galaxy. The student will use the IDL data analysis environment to write a code that convolves all the data to an equal resolution and then conducts a spatial cross match, looking specifically for coincident enhancements in emission, finally testing whether they are statistically significant. This will also involve developing a method to deconvolve the two components of FIR emission from the HVC and the Milky Way. Successful identification of star formation in HVCs would
provide a fresh challenge to our preconceptions about where stars can form, and motivate new paths of research in this field. (Co-mentored by D. Stark; funded.)
Galaxies with Anomalous Kinematics
The RESOLVE Survey aims to have a very complete inventory of galaxy rotation velocities, ultimately enabling a 3D census of dark matter. However, rotation velocities measured with the radio 21cm line (tracing neutral hydrogen) and optical emission lines (tracing ionized hydrogen) do not always agree. One way this can happen is that galaxies can have strong ionized gas outflows due to either central starbursts or supermassive black hole growth. In this case, the raw data may actually reveal two kinematic components in the ionized gas, one outflowing and one rotating. For this project, the student will first develop an IDL software tool to identify multi-component kinematics in optical emission line data by measuring moments and performing multi-component Gaussian fits for the velocity distribution at each spatial point. The tool will simulate data with different signal-to-noise levels to set thresholds for identifying complex kinematics. Applying this tool to the RESOLVE Survey, the student will then extract all galaxies with kinematically anomalous ionized gas in the Survey archive to date. Using this subsample of galaxies and the measurements from the new kinematics tool, the student can pursue a variety of follow-up
investigations, including determining the main physical causes of such kinematic anomalies and/or devising ways of measuring rotation velocities despite the presence of anomalies, using radio data and fit/moment information. (Co-mentored by K. Eckert; currently available only by fellowship.)
Project with Prof. Miller.
How trees survive hurricanes: drag reduction of broad leaves in strong winds.
Flexible plants, fungi, and sessile animals are thought to reconfigure in the wind and water to reduce the drag forces that act upon them. In strong winds, for example, leaves roll up into cone shapes that reduce flutter and drag when compared to paper cut-outs with similar shape and flexibility. Simple numerical simulations of a flexible beam immersed in a two-dimensional flow will also exhibit this behavior. What is less understood is how the mechanical properties of a two-dimensional leaf in a three-dimensional flow will passively allow roll up and reduce drag. In this project, the student will use computational fluid dynamics and flow visualization to determine how leaves roll up into drag reducing shapes during storms. The programming language involved is MATLAB with visualization in VisIT and/or Paraview. In addition to gaining insight into mechanical adaptation in the natural world, this project might also inspire innovation in the engineering of structures and underwater vehicles. (Co-mentored by S. Jones; currently available only by fellowship.)
Project with Prof. Oldenburg.
Light Scattering from Coupled Plasmonic Gold Nanoparticles.
Noble metals like gold have a special property known as surface-plasmon resonance, where light induces collective excitations of electrons that resonate on the metal surface. In gold nanoparticles, this is observed as a large optical signal that is of high interest in optical sensing applications. My laboratory specializes in biological sensing using these types of nanoparticles. Our group maintains a number of light scattering computational tools that we employ to predict the optical signals from gold nanoparticles, the latter of which are provided by our collaborator, Dr. Joseph Tracy at NCSU. In this project you will be computing the light scattering behavior of multiple gold nanospheres when they are in close proximity to one another. The proposed project is to use C# and Matlab to model how one can sense the proximity of gold nanospheres with one other based on their light scattering signals, which has potential applications in biomedicine and materials. (Co-mentored by A. Pope; currently available only by fellowship).
Project with Prof. Superfine.
The Mechanical Properties of Living Cells.
Cells are remarkable mechanical objects, able to move across substrates and in 3 dimensions, able to alter their shape to invade between other cells, able to divide into new cells and able to sense their mechanical environment to change their very identity. We are studying this behavior in a variety of ways including the application of forces to cells using magnetic beads, and monitoring the behavior of the cell shape, stiffness, tension, motility and cell differentiation. We need to develop methods for computing the cell mechanical properties and response by starting with advanced imaging to obtain 3D images of cells, translate this data into cell geometries, and then apply finite element codes to interpret the responses we observe in our experiments. Students will likely apply a variety programming environments including MATLAB, COMSOL as well as specialized codes within the research group. (Co-mentored by L. Osborne; funded.)
Project with Prof. Washburn.
Functionalized Composite Nanorods.
Nanorods will be grown by electrochemical methods in nanometer sized (diameter) pores. The rods will have segments from different materials and one goal of the project is to control the interface between the two materials. Another goal is to characterize the structure of the rods by electron microscopy. Yet another goal is to study the electronic properties and the light-scattering properties of individual rods. The student will learn to work with the powerful COMSOL computational modeling package and generate code in Matlab to analyze the results of the simulations and to compare those to the experimental results. (Co-mentored by N. Williams; currently available only by fellowship.)
Projects with Prof. Wilkerson (2 of the 3 below).
The Experimental Neutrino and Particle Astrophysics group is involved in experiments aimed at understanding neutrino properties, searching for dark matter, and performing tests of fundamental symmetries. Currently our two major experimental efforts are the Majorana Demonstrator 76Ge based search for neutrinoless double beta decay and the Karlsruhe Tritium Beta Decay Neutrino Mass experiment. Within these two activities have a wide variety of opportunities for computational projects including:
Large scale Monte Carlo and Simulations
Will use GEANT4, a toolkit to simulate the passage of particles through matter, and ROOT an analysis framework for a project involving either the Majorana Demonstrator or KATRIN. Both GEANT4 and ROOT are written in C++. May also involve use of Python. (Co-mentored by G. Giovanetti, J. Strain, or F. Fraenkle; funded.)
GPU and supercomputer based calculations for KATRIN
Related to computing electrostatic fields using the Boundary Element Method and discretization algorithms for the KATRIN spectrometer and detector electrode surfaces. Will use C++ framework, but also specialized GPU programming tools. (Co-mentored by T.J. Corona; funded.)
Real-time Data Acquisition (could be multiple projects)
Using ORCA (Object-oriented Real-time Control and Acquisition) software system designed for dynamically building flexible and robust data acquisition systems for nuclear and particle astrophysics experiments where there are a variety of potential projects spanning development of code for hardware modules, advanced scripting, near-time display tools, and support of smart phones and tables. ORCA is written in Objective C. (Co-mentored by M. Howe; funded.)