Senior Projects of the Class of 2003
(updated November 1, 2002)
Aaron Adalja with Cyrus Taylor
Using Derivatives to Model Energy Assets
A derivative is a financial instrument whose value depends on the value of more basic underlying variables. Most commonly, these variables are the prices of traded assets. Through the use of stochastic modeling with differential equations, one can effectively price any derivative. By examining derivatives of energy assets, our goal is to address some of the problems unique to valuing energy assets.
Audrey Alabiso with Corbin Covault
Calibration of GPS Units for the Pierre Auger Project
The Pierre Auger Project is a high energy astrophysics collaboration that is trying to determine the mass composition, arrival direction and energy of cosmic ray air showers above 10^19eV. This is accomplished by using a series of 1600 particle detectors, and an atmospheric fluorescence detector. Each particle detector will have a Global positioning System (GPS) attached which will be used to precisely tag the time an event hits a particular detector. This project will concentrate on the calibration of each of the 1600 GPS units with each other and the triggering hardware and software attached to each particle detector.
Benjamin Bayat. with Amy Eroh (IBM Burlington) & Kathy Kash
Volume Logic Diagnostics on Microprocessor and ASICs Chips at IBM
The fabrication of semiconductor chips in industry is both a complex and lengthy process, involving the application of cutting edge nanotechnologies over a period of two to three months. Of obvious importance is the research and design of the circuit architecture. However, the most poignant question is not “what is to be made”, but “how it is to be made”. It is through characterization, diagnostics and other yield learning tools that this question is answered. Defects that occur during fabrication can develop into fails, destroying the functionality of the semiconductor chip. Currently there are many methods of detecting these defects in order to analyze, define and “root cause” their origin. These methods include KLA optical devices, SEM failure analysis tools, and inline health monitors such as the LSM.
However, the more complex the logic of semiconductor chips becomes the more difficult the process is for translating the diagnostic data into a physical location. A promising solution to this problem is the analysis of volume logic diagnostic data. Using data from a wealth of other tools, optical pictures can be overlayed with wafer final test electrical data to produce the exact failing nets that occur from the detected defects. These locations will be submitted to failure analysis to gain hard evidence of the defect. Finally, several frequently occurring fails will be investigated with an understanding of the fabrication process to offer possible sources for the origin of the defect.
Thomas Bing with Dr. Philip Taylor
The Changing Shape of a Liquid Drop in an Electric Field
Ordinarily, a liquid droplet is essentially spherical. When a dielectric liquid drop is placed in an electric field, however, a spheroid results. Provided the liquid’s dielectric constant is above a certain threshold value, a further increase in field strength will result in the drop forming conical tips, becoming lemon-shaped.
In this project, we will model the shape such a droplet assumes by formulating equations that govern the droplet’s shape and then numerically solving them.
Joshua Boehm.with Corbin Covault
Characterizing the Effects of Atmospheric Conditions on the Sensitivity of the STACEE Experiment
The STACEE experiment hinges on its ability to detect Cherenkov pulses of light and distinguish them from the night sky background. Weather conditions such as cloudiness or haze result in increased attenuation of the Cherenkov light as well as greater scattering of background light producing extra noise. This project will investigate the data generated by the SAM (STACEE ATMOSPHERIC MONITOR) data collection devices which record weather conditions and measurements of atmospheric transparency. Correlations will be sought between the SAM data and other STACEE observables with the goal of setting quality cutoffs and calibrating the energy scale on the
collected STACEE data.
Robert Hous with Mehran Mehregany
Mechanical Characterization and Design of Flexible Silicon Carbide Microstructures
This project will investigate the feasibility of utilizing silicon carbide (SiC) in miniature flexible ribbon cables. These cables have applications in implantable neural sensors, where their flexibility and biocompatibility make them ideal for such applications. Previous works using Boron doped Silicon show great success, with the biggest disadvantage of the Boron doped Silicon being its relative fragility. This study will measure the material strengths of SiC, and then compare these findings to the previously measured strength of Boron doped Si. Material strengths for the SiC will be recorded for a variety of different structures. Each structure will be stressed to the point of failure in either a bending, twisting, or pushing mode to determine exact values for the structure’s strength.
Andrew Huss with Stephen Phillips (Electrical Engineering)
Integration of Sensor Technology for Mini-WHEGS Robot
WHEGS stands for wheels with legs. The mini-WHEGS robot is approximately the size of a pack of playing cards, and possesses great power and agility for its size. It can maneuver over or around almost any obstacle, and has potential applications as a research or surveillance tool. In order to be useful, however, it must contain a sensor package with control mechanisms that allow it to collect useful data and transmit or store the information effectively. Initially, I will explore the potential for including tactile sensation and video, audio, and infrared data acquisition. As my knowledge develops, I will attempt to create a working product based on these findings. A primary objective is to give the robot rudimentary knowledge of its orientation and location in relation to nearby obstacles. The next goal is for it to acquire reliable data of some kind. In both cases, new hardware must be integrated with the communications system, possibly a palm pilot. Due to space and weight constraints, I will take advantage of the control electronics that are present on the existing robot.
Timothy Janezic with Glenn Starkman
Numerical Solutions of the Gravitational Potential in 5H and 6H Dimensional Universes
Fields living in the universe can be decomposed into eigenmodes, determined by the geometry and topology. However, only the simplest cases can be done analytically. Attention has focused on these cases largely for that reason. An attempt will be made to numerically solve for the gravitational potential in 5+1 and 6+1 dimensional universes which factorize into 3+1 dimensional "ordinary spacetime" and 2 or 3d extra-dimensional manifolds, including manifold factors with curvature. These eignemodes will then be used to understand the physics of kaluza-klein degrees of freedom in universes with "large" extra dimensions.
Justin Kenny with Ken Singer
Surface Electromagnetic Waves in Cholesteric Liquid Crystals
Surface electromagnetic waves (SEWs) are predicted to form on the surface of cholesteric liquid crystals (CLCs) at an interface when interacting with light. In theory the presence of SEWs is dependent on the frequency of the incident light, the angle of incidence of the incoming light relative to the sample, and the incident azimuthal angle relative to the director on the surface of the CLC. The theory of SEW formation will be explored and verified experimentally using the ATR (Attenuated Total Reflection) method.
Brian Kubit with Phil Taylor
Theoretical Approach to the Physics of Batteries and Fuel Cells
Batteries and fuel cells work by the transfer of ions from one place to another under the influence of electric fields and concentration gradients. In this project we will be calculating the rate at which ions can transfer by solving the transport equations that govern this process. Some of this work will involve analytical theory and some will involve using computers to obtain numerical solutions.
Kevin Mantey with Rolfe Petschek
Properties Of Molecules That May Be Ultra High Temperature Superconductors
It has been recently discovered that certain molecules based on nickel dithiolenes may contain Cooper pairs so that appropriate assemblies thereof may form high temperature superconductors. As the excitation energies in these molecules are about 0.1 eV, corresponding to thousands of Kelvin, superconductivity might persist to very high temperatures. In this project, quantum-chemistry programs, particularly the GAMESS Generalize Atomic and Molecular Electronic Structure System1, will be used to calculate the ground state properties of various nickel dithiolenes. Although 0.1 eV is large on the thermal scale it is very small on the energy scales of electronic excitations. Therefore, various numerical approximations will be used to verify or disprove these results. Simple analytic theory will be used to help guide the nature of the numerical calculations and to help understand which molecules can usefully be examined. Time permitting, the project may also involve examining theories relevant to understanding how such molecules, provided they do contain Cooper pairs, can form bulk superconductors2,3,4.
“The GAMESS Generalized Atomic and Molecular Electronic Structure System” M.W.Schmidt, K.K.Baldridge, J.A.Boatz, S.T.Elbert, M.S.Gordon, J.H.Jensen, S.Koseki, N.Matsunaga, K.A.Nguyen, S.J.Su, T.L.Windus, M.Dupuis, J.A.Montgomery J.Comput.Chem. 14, 1347-1363 (1993)
2 “Effect Of Quasi-Particle Tunneling On Quantum-Phase Fluctuations And The Onset Of Superconductivity In Antigranulocytes Films” Chakravarty S, Kivelson S, Zimanyi GT, Halperin BI Physical Review B-Condensed Matter 35 7256-7259 (1987)
3 “Quantum Critical Phenomena In Charged Superconductors” Fisher MPA, Grinstein G Physical Review Letters 60 208-211 (1988)
4 “Continuous quantum phase transitions” Sondhi SL, Girvin SM, Carini JP, Shahar D Reviews Of Modern Physics 69 315-333 (1997)
Cameron McBride with Glenn Starkman
The Propagation of Light and Gravity through Matter-filled Spacetime with Stabilized Compactified Extra Dimensions
The idea of extra dimensions beyond the usual four is far from new. In the 1920s, Kaluza and Klein postulated an extra dimension in an attempt to unify the theory of gravity with electromagnetism. While not completely successful, the idea continues. Modern string theory requires 10 spatial dimensions to maintain mathematical consistency. There are also attempts to use large extra dimensions to solve the hierarchy problem -- the large ratio between the electroweak and Planck energy scales, which is manifested by the weakness of gravity in relation to the other forces.
In the standard approach to string theory, the extra dimensions exist as finite curled up ("compactified") spatial dimensions with sizes on the order of the Planck length (10^-35 meters). In 1998, Arkani-Hamed, Dimopoulos and Dvali proposed that these could be as large as 100 microns to a millimeter, if ordinary matter (standard model particles) is confined to a three-dimensional membrane (or "brane") within the multi-dimensional space (or "bulk"). The spreading out of gravitational field lines in the bulk would then explain the apparent weakness of gravity.
Whether large or small, one can ask why the extra dimensions are the size that they are -- why don't they expand or contract like the ordinary dimensions? The usual answer is that there is some dynamical mechanism (vaguely specified) which stabilizes them. Whatever that mechanism, we should expect the size of the extra dimensions to respond, even if only slightly, to the presence of mass. Gravity and light (unless it is confined to a brane) propagating through space should 'sense' the changing size of the extra dimensions. This should cause phenomena such as bending or retardation of light or gravity waves.
The behavior of waves traveling through inhomogeneous extra dimensions will be investigated. An attempt will be made to use the results to constrain theories of extra dimensions.
Sonali Mehandru with Bob Brown and Jingzhi Liu
Investigation of Functional MRI Theory and Applicability to Brain Functioning via the BOLD Technique with Secondary Analysis of Related Electrophysiological Methods
Modern medical imaging techniques have been revolutionized with the introduction of magnetic resonance technology. By exploiting the properties of the ubiquitous hydrogen spin, MRI powerfully captures stationary images of complex anatomical structures. However, to reveal the more dynamic processes that characterize anatomical functioning, especially within the brain, an equally more dynamic imaging mode has been developed. Functional MRI builds on the strength of frequency-dependent signals under varying field gradients with additional methods to visualize changes in physiological states. A specific feature of fMRI is its application of the BOLD (Blood Oxygenation Level Dependent) technique in which changes in blood susceptibility promote phase shifts in relation to the external magnetic field. This study explores the techniques and applications of fMRI in conjunction with the techniques employed in electroencephalography (EEG) and electromyography (EMG) to investigate some critical connections between central cortical activity and macroscopic behavior.
Justin Morgan with Arnold Dahm
Directional Diffusion of Isotropic Impurities in an HCP Crystal of Solid Helium
At a certain temperature and pressure, 4He will crystallize in an hcp lattice. It has been seen that vacancies in a 4He lattice propagate as waves in straight lines along the planes of the crystal. Previous experiments to measure the parameters of these waves have reported significantly varying results. This project will measure the parameters of the vacancy waves by doping the solid 4He with 3He, which diffuses throughout the lattice by tunneling into vacancies. NMR techniques will be used to measure the diffusion rate in a sample of 4He after the spins have been saturated with a large RF pulse. The diffusion rate will be measured along three orthogonal axes in an effort to prove that the 3He is diffusing anisotropically.
Dominic Reali with Maureen McEnery (Medical School)
Quantum Dots in Biological Imaging
At the present, most biological imaging is done using organic fluorescent molecules (known as fluorophores). These are coupled to antibodies which then attach to the specific protein or sample that the scientist wishes to study. Through fluorescent microscopy, the scientist shines a light on the sample, exciting the fluorophores, which then emit a photon in order to return to ground state. This emitted photon is has a lower energy and thus a different color from excitation photon provided by the scientist. Thus, through the use of filters, the background light from the excitation photon can be eliminated and the scientist sees only the light from the fluorophores attached to the desired sample.
This system, however, has some drawbacks. For one, fluorophores are subject to photobleaching. Over time, exposure to light will destroy the fluorophores. Also, each fluorophore only emits a broad spectrum with a continuous range of wavelengths, potentially overlapping with the emission or absorption spectra of other fluorophores. These problems can be resolved using quantum dots. Semiconductor quantum dots contain a finite number of “free” electrons that can act like the electron cloud of an atom. These electrons can be excited just like the electrons of atoms, and like those electrons, they will emit photons to return to the ground state. The advantages here over fluorophores are that this excitation/emission interaction is not destructive and the emitted photons have discrete wavelengths due to the nature of the interaction. In addition, quantum dots can be synthesized to emit photons of virtually any wavelength.
Here, we are attempting to exploit these and many other advantages of quantum dots over fluorophores by coupling them to antibodies instead of fluorophores for use in biological imaging and the detection of biological toxins.
James D. Rodgers III with Patricia Higgins (Frances Payne Bolton School of Nursing) and Cyrus Taylor
Using the Actilume to Measure Light in an Intensive Care Unit: A Methodological Study
The proposed project will measure the congruence between the Ambulatory Monitoring Inc. actilume and a calibrated light meter. The actilume is a light sensor, located in the Sleep Watch-L, a wrist monitor that individuals wear as an unobtrusive device for measuring activity and sleep using an accelerometer. Both the actilume and the accelerometer collect data over a 24 hour period. The data are then downloaded into a software program for statistical and graphical analysis. Simultaneous measurement of light data from both the actilume and the light meter will provide a means to determine the accuracy and validity of the actilume. The AMI actilume is currently being utilized in a study to determine how non-pulmonary factors affect patient weaning from ventilators in the intensive care unit (ICU) (Adult Failure to Thrive in the Long-term Ventilator Patient, NR-05005, Patricia A. Higgins, RN, PhD, PI). There are no known studies that have used the actilume in an ICU setting. The project will be built around a theoretical understanding of construct validity, the physical nature of light, how light affects the human eye physiologically, and to what extent light can be manipulated to improve the environment in the ICU.
Steven Rodney with Corbin Covault, Glenn Starkman & Craig Copi
Simulations for the X-Ray Occulting Steerable Satellite (XOSS)
Current X-Ray telescopes are not operating to their fullest potential in terms of angular resolution. The x-ray diffraction limit for a 1-m aperture (such as CHANDRA’s) is about 0.3 milli-arcseconds, but the best resolution yet achieved is closer to 0.5 arcseconds. Planned x-ray telescopes will further sacrifice angular resolution to increase their x-ray collection. The XOSS project is a proposal for a large sheet in space that will occult x-ray sources while an existing telescope observes them, dramatically increasing the angular resolution of the telescope. Some current concerns of the project are the optimization of the mask pattern and the actual angular resolution benefit conferred by the XOSS. We will test various mask patterns using computer simulations of observations to feed our image reconstruction algorithm. We will then create a scaled-down model of the XOSS with the actual mask patterns to create a real simulation of the imaging process.
Clinton Schmidt with Dan Akerib
Monte Carlo Simulation of a Neutron Rejection Technique in Dark Matter Detection
The Cryogenic Dark Matter Search (CDMS) attempts to detect dark matter in the form of Weakly Interacting Massive Particles (WIMPs). The detectors used for the project are cooled to low temperatures to allow for the detection of scattering from nuclei by measuring the energy transferred to a nucleus. Most of the particles that interact with the detector are charged particles that interact with the electrons in the detectors. Such interactions are characteristically different from nuclear scatterings and can be independently identified and eliminated from the collected data. Neutrons, however, do not interact with the electrons, but rather scatter off the nuclei on the detector in the same way that WIMPs would.
The second Phase of the CDMS will take place underground in a mine, so that the surrounding rock will shield the detectors from the majority of cosmic rays that create most of the background events that need to be rejected. Neutrons produced by high-energy muons in the rock walls produce neutrons that are particularly hard to reject. The detectors can be shielded from low energy neutrons, but these higher energy neutrons pass through that shielding and interact with the detector. However, the production of the higher energy neutrons is accompanied by production of numerous other charged particles in the rock wall. The charged particles do not travel far in the rock, but the neutrons can travel a significant distance. It is proposed that streamer tubes placed in the rock wall to detect these charged particles will allow a useful veto signal to be created. Any nuclear recoil in the detector that coincides with a charged particle interaction in the streamer tube will be rejected as a neutron event and not a WIMP interaction. Before this method is put to use, particle-transport Monte Carlo simulations will be used to determine its effectiveness.
Sharon Stefanovic with Lawrence Krauss & Cyrus Taylor
Information and Genetic Evolution
All genetic information necessary for reproduction is passed from generation to generation through DNA. Just how this information is processed during the DNA replication process is of vital interest in understanding the mechanics of genetic evolution of species.
We will attempt to explore how mutation rates are related to error coding, and how this relates to the sequencing of the human genome. The project may include the continuance of previous students’ work involving the dynamics of genetic drift. The actual amount of unique information contained in a genetic sequence, and the entropy of that information, are of interest. As a first step, the compressibility of a sequence of data using a general zip algorithm asymptotically yields the amount of entropy in the sequence1.
1. Benedetto, Dario, Emanuele Caglioti, and Vittorio Loreto. “Language Trees and Zipping.” Physical Review Letters, V. 88, No. 4. 28 January 2002.
Steven Stroiney with Lawrence Krauss
Axions, Quintessence and Naturalness
We will explore the issue of naturalness as it relates to one of the prime candidates for "quintessence"... a scalar field in a slowly varying potential that mimics, for some time, a cosmological constant in the Universe. The field we will examine is a pseudoscalar "axion-like" field whose symmetry breaking scale is at the Planck scale.
Jonathan Wheeler with Clemens Burda (Dept. of Chemistry)
Investigations of the Optical Properties of CdS Nanoparticles for Potential Applications in Spintronics
The goal of this project is to investigate the optical properties of Cadmium Sulfide (CdS) semiconductor nanoparticles using spectroscopic techniques such as UV-vis, fluorescence and laser spectroscopy in the femtosecond time regime. Preliminary studies on how the properties of these materials are affected by its chemical environment (i.e pH of medium and effect of ligand ) will first be evaluated to provide a basic understanding on the nature of these materials. After acquiring adequate understanding on the basic properties of CdS nanocrystals, techniques for doping with ferromagnetic transition metals and possibly rare earth Lanthanides will be explored. The unique magneto-optical properties of these materials will be examined for potential future applications in the area of spintronics.