The electrical properties of amorphous and crystalline titanium dioxide polymorphs are reported. Titanium dioxide is a widely used transparent semiconductor and it is a useful oxide model. Using variable temperature transport measurements of thin films, it was possible to establish the activation energy barrier for conduction. This was accomplished using...
Brownian motion is the movement of a particle in a fluid resulting from collisions with surrounding molecules. It has modern applications in simulating fluid dynamics and the motion of proteins in biophysics. Brownian motion simulations generally evolve the initial state by applying Newton’s second law to every particle. These simulations...
High resolution images of a dim companion in a binary star system can be obtained using a Digital Micromirror Array (DMA) as an optical mask. Imaging can be problematic because the intense light from the main star can saturate the detector and leave the companion unnoticed. Placement of the DMA...
Cancer is a hard disease to control because of its ability to spread to different parts of the body. Cancer cells can spread out from a primary tumor to distant organs which gives rise to new cancer cell colonies and more tumors over time. This process is known as metastasis...
Multivariable functions permeate physics, mathematics, and other sciences. Understanding how quantities in multivariable relationships change together – or co-vary – is important for studying physical systems. In this project, we asked junior-level physics majors to describe the covariation of quantities in a multivariable context given a 2D graph. We identified...
In 1877 John Kerr described an experiment that demonstrated a quadratic change in refractive index in a plate glass placed in a strong external electric field. This results in a nonlinear relationship between the average electric polarization within the materials and the intensity of the applied electric field. This opened...
Exciton-polaritons are a form of light-matter coupling that have potential applications as photonic transistors and logic gates. In order for a photonic transistor or logic gate to be integrated with room temperature fiber-optic technology, excitons-polaritons need to be stable at room temperature and compatible with the red and near-infrared wavelengths...
Semiconductors serve an integral role in our technologies today. However, with new advancements in ultra-fast electronics, we are approaching the fundamental speed limits of traditional silicon-based semiconductors. Silicon-based semiconductors typically exhibit photocarrier dynamics in nanosecond timescales. Transition metal dichalcogenides (TMDs) are 2D materials shown to exhibit photocarrier dynamics in picosecond...
By alloying face centered cubic CaSe with orthorhombic SnSe, we created the heterostructural alloy
Sn1-xCaxSe. The phase separated lms created with a high deposition temperature acted as highly crys-
talline SnSe while the low deposition temperature lms acted as a mix of SnSe and CaSe. For the alloyed
lms we...
Computational statistical mechanics leans heavily on the class of Markov Chain Monte Carlo Algorithms. Many such algorithms exist, and simulations can run for several weeks, making the selection of algorithms a difficult, but critical task. In this work, we introduce a benchmark system of two quadratic wells with an analytical...
We explore the interactions between charge transfer exciton states (CTEs) and an optical microcavity by testing the effects that cavity resonance has on the CTEs and if CTEs can be coupled with a photon to create quasiparticles known as polaritons. Exciton polaritonics is becoming a booming area of research mainly...
We construct the contact value approximation (CVA) for the pair distribution function,
g(²)(r₁, r₂), for an inhomogeneous hard sphere fluid. The CVA is an average of two radial
distribution functions, which each take as input the distance between the particles, |r₂ −r₁|,
and the average value of the radial distribution...
Standard quantum mechanics makes foundational assumptions to describe the measurement process. Upon interaction with a “classical measurement apparatus”, a quantum system is subjected to postulated “state collapse” dynamics. We show that framing measurement around state collapse and ill-defined classical observers leads to interpretational issues, and artificially limits the scope of...
The standard model (SM) of particle physics describes many of the experimentally observed subatomic particle interactions. However, there are a few discrepancies with the SM namely: matter/antimatter asymmetry and dark energy. A current extension of the SM allows for small amounts of Lorentz Violation to fix these discrepancies. Lorentz Violating...
Terahertz (THz) spectroscopy is a great tool not only to study fundamental physical processes such as many-body Coulomb interaction but also to develop ultrafast electronic devices. More specifically, intense THz fields interacting with semiconductors have exhibited strong nonlinear effect involving extreme carrier dynamics. In this experiment, intense THz radiation was...
An experimental apparatus is modified to allow measurements of the Seebeck coefficient and resistivity to be taken simultaneously. This apparatus is designed for bulk and thin film samples between temperatures of 10 K and 300 K. The apparatus is constructed such that these simultaneous measurements do not interfere with each...
Past studies have shown that students struggle with main concepts of potential energy, such as reading graphs, understanding that potential energy can be negative, and, most pertinent to this research project, connecting potential energy to force. I designed an activity to help introductory physics students address these struggles. The activity...
The response of cells to periodic driving is important for many biological processes, particularly blood flow and heart functioning. Our research analyzes the collective shear stress response of fibroblast cells due to a periodic driving frequency. When cells experience shear stress, they release calcium into the cytosol. To quantify the...
Understanding charge transfer in organic semiconductors is important for developing devices like organic light emitting diodes and flexible electronics. Optical tweezers have been used in many disciplines for trapping, manipulating, and analyzing microscopic objects such as microspheres, micro-organisms, and other colloidal particles. Using optical tweezers, studies have measured the average...
Spectroscopic ellipsometry (SE) is used to characterize amorphous and crystalline thin films of TiO2. Amorphous precursor films of TiO2 are deposited by radio frequency magnetron sputtering on fused silica and silicon substrates. Annealing the amorphous precursor films induces them to crystallize into either pure or mixed phases of the three...
Chain rules are critical to the process of solving many thermodynamics-related partial derivatives. This study evaluates the solution method and error evolution of students’ responses to a pair of chain rule problems in an upper-level undergraduate thermodynamics course. Students’ responses were categorized by solution method. Students’ solution methods included implicit...
The motor protein dynein is responsible for cellular processes such as axonal transport and cell division by delivering vital information along the microtubule track. A failed delivery can cause severe damage to the cell’s functionality and lead to neurological diseases. Despite dynein’s rich history in cellular research, the mechanism of...
We construct a Monte Carlo simulation in Python to calculate optical flashes at 5x10¹⁴ Hz peaking at 6x10³¹ erg s⁻¹Hz⁻¹St⁻¹ due to synchrotron radiation from the reverse shock of a gamma-ray burst’s jet. While analytical solutions to this problem exist, they rely on sweeping simplifications of what is necessarily a...
Monte Carlo methods are used to explore vapor-liquid phase transitions. However, current models are computationally expensive when identifying these phase transitions. Traditionally, Monte Carlo simulations are run across a range of temperatures at a fixed number of atoms/molecules. The Number Monte Carlo method (NMC), our proposed Monte Carlo method, runs...
Dynein is a motor protein which transports cargo along tracks inside the cell. Like related motor proteins kinesin and myosin, dynein uses cellular energy to take steps with its two foot domains. Unlike kinesin or myosin, dynein’s stepping pattern is highly varied: it can take steps between zero and 60nm...
Dynein is a motor protein which transports cargo along tracks inside the cell. Like related motor proteins kinesin and myosin, dynein uses cellular energy to take steps with its two foot domains. Unlike kinesin or myosin, dynein’s stepping pattern is highly varied: it can take steps between zero and 60nm...
The purpose of this project is to verify scattering mechanisms in semiconductors by measuring transport properties and producing data that reflects existing research. The Hall effect is utilized to measure the resistivity, mobility and charge carrier concentration of the semiconductors: indium tin oxide (ITO), p-type silicon, and n-type silicon. By...
Motivated by the Navier-Stokes equations, which are a set of unsolved equations related to fluid motion in R^3, we explored the incompressibility condition and the Neumann boundary problem. After exploring, we noticed that using iterated Riesz transforms of the boundary data could be used to get information about the velocity...
Semiconducting materials are of immense importance due to their presence in almost all modern devices. It is possible that the surface physics of semiconductors could be used to control the nanoscale topography and properties of these materials, ultimately creating new options for device fabrication. This could result in profound implications...
The Laser Gravitational Wave Observatory, or LIGO, is built to observe gravitational waves as they propagate through space. Advanced LIGO is extremely sensitive
to movements of the test mass as small as 10⁻²¹ m/√Hz , which allows many signals other
than gravitational waves to be detected by the system. Pressure...
A flipped classroom provides students with course content in the form of videos, readings, and/or simulations that they complete during the time traditionally used for homework assignments while in-class time is devoted to hands-on group learning activities. Project BoxSand is gathering quantitative data on how students in a flipped classroom,...
Transparent conductive oxides (TCO) are at the forefront of technology with their uses in
touch screen phones and televisions, solar cells and more. Titanium dioxide and tin dioxide are two TCOs that have been studied in depth on their own, so to further explore these TCOs, this project focuses on...
Metal organic frameworks(MOFs) are a class of crystalline materials utilized in gas storage, chemicalsensing, and other engineering applications. Recently chemists have begun synthesizing MOFs withmoving parts in order to further these applications. A wide array of dynamic MOFs have been created andtheorized. Among them is the interlocking of a ring...
Organic photovoltaics are being explored as the next generation material for semiconducting and optoelectronic devices but are limited by their stability and efficiency. One new candidate is crystallized Anthradithiophene (ADT), which is a promising photo-voltaic material due to its high quantum yield and adjustable side groups. The side derivatives TES-F,...
Plasmon induced transparency (PIT) describes a spectral response of coupled plasmonic resonators in that coupling between bright and dark modes leads to a destructive interference resulting in a narrow transparency window. This process has many applications in material characterization and advanced optical devices such as slow light devices or ultrafast...
Organic semiconducting materials have emerged in the last few decades as viable alternatives to inorganics in broad applications from field effect transistors to LEDs to solar cells. Organics provide many benefits over inorganics such as flexibility, sustainability, and reduced cost. However, these materials are more susceptible to degradation in the...
This research investigates the electronic properties of a fungi-derived pigment, xylindein
as a novel sustainable material for organic electronics. Xylindein molecules were characterized in solution and in film. Absorption spectra and (photo)luminescence spectra were
taken at various excitation wavelengths. Xylindein’s molecular properties were computed
with the Gaussian 09 software suite....
In industry, there is considerable interest in finding sustainable, renewable materials for use in electronic devices. Pigments derived from spalting fungi are of particular interest due to their longevity in diverse environmental conditions. The focus of my project was to characterizethe properties of a novel, fungi-derived pigment, and to discover...
Optical trapping is a tool used throughout a wide variety of disciplines rang- ing from precisely probing and manipulating sub-micron organisms in biol- ogy to analyzing fundamental charge transfer in colloidal physics. This thesis presents research involving optical tweezer force measurements of polystyrene and silica microspheres. In addition, preliminary work...
This study used SCOUT optical modelling software to create models of the reflectance and transmittance spectra generated by mixtures of titanium dioxide (TiO2) and tin oxide (SnO2). These models enabled identification of how altering the ratio of a mixture changes the optical response. By being able to identify how altering...
The optical transition in high-fraction polymorphs of titania (TiO2) were investigated to determine the band gap behavior of the most common polymorphs—brookite, rutile, and anatase—the values of which are varied in the literature. The direct optical band gaps of brookite, rutile, and anatase, were determined to be 3.37(7)eV, 3.41(11)eV and...
This thesis looks at the third harmonic voltage response of a small incandescent lightbulb. The third harmonic voltage, or 3 omega (3ω) voltage, arises from applying a 1ω sinusoidal voltage across a resistive material. The 3ω voltage carries with it information about the thermal conductivity of the material. A lock-in-amplifier...
When a star dies in a supernova, its constituent particles are torn apart and a gaseous cloud of atoms remains. These atoms may eventually condense again into large bodies such as planets and stars. There are three main theories as to how this happens: classical, kinetic, and non-local thermodynamic equilibrium...
The thermal cross sections and resonance integrals for neutron capture by ⁷⁴,⁷⁸,⁸⁰,⁸²Se were measured using the same procedure and equipment for all of the isotopes. Uncertainty and absence of accurate previous values for several isotopes introduces a need of measuring these parameters using similar techniques. This was done using OSU’s...
The neutron capture cross sections of ¹⁰⁶Cd, ¹⁰⁸Cd, ¹¹⁰Cd, ¹¹²Cd, ¹¹⁴Cd and ¹¹⁶Cd
were determined in the present project. Four different OSU TRIGA reactor facilities were
used to produce redundancy in the results and to measure the thermal cross section and
resonance integral separately. When the present values were compared...
Currently multi-canonical, and grand canonical Monte Carlo simulations exist, but do not always give all of the necessary information of the system. When using a 1-D (only changing in one variable) broad histogram Monte Carlo method a user would need to run a range of simulations in order to get...
Fluorescent proteins have emerged as an essential toolset for bioimaging, creating a demand for engineering proteins with new and improved fluorescent properties. In this thesis, I explore the atomistic structure of REX-GECO1, a newly engineered protein biosensor that has unique optical properties. Since this protein has no available crystal structure,...
We computationally modeled protostellar star-disk systems with star to disk mass ratio of 10. Our computational models looked at the development of density perturbations in these systems for different geometries of the system. The ratio of the star’s height and radius (rₚ/rₑ) is varied between 0.1746 and 0.88095. We modeled...
Organic semiconductors are a promising alternative to the traditional inorganic semiconductors, such as silicon. Organics are solution-processable, low-cost, sustainable, and have interesting optoelectronic properties. One such property is the formation of exciton-polaritons, quantum quasi-particles formed by an electron-hole pair in the semiconductor and a photon. This process can be induced...
The Min protein system in Escherichia coli helps the cell division process by identifying the center of the cell [1, 7]. This system has been modeled succesfully computationally under standard conditions. There has been recent experimental interest in the cell division process for significantly perturbed cell shapes. We take the...
This thesis presents a measurement of the resonance integral and thermal cross section – which together represent the total neutron absorption cross section – of the naturally occurring isotopes of platinum that emit gamma radiation upon neutron absorption. The measurements were made via neutron activation analysis. Platinum samples were bombarded...
This investigation expands on earlier methods of using surface polarization reflection (SPR) to characterize the first few monolayers of a surface. Past research measured intensities of light reflecting off an SiO₂ optical flat inside a vacuum. Pressure of applied gas was changed to view a change in reflection. In an...
Current methods in traction force analysis rely on a homogeneous extra-cellular matrix and
embedded microbeads to track deformations. The efficacy of these methods decreases when the matrix is not homogeneous. In heterogeneous matrices, beads often aggregate in regions of higher matrix density and float in regions where matrix substrate is...
Impedance spectroscopy is a method of modeling materials with equivalent circuits to determine electrical properties, such as the resistivity and the dielectric constant. We explore impedance spectroscopy, both theoretically and experimentally through applying the method to samples of BaCuS1-xSexF. Grain boundary effects were dominant in the results, and although they...
Quantum yield is an important, characteristic quantity to be measured for fluorescent compounds. Here, a comparative method between fluorescent compounds in solution is applied to measure unknown quantum yields. An absorption spectrometer was used to measure the absorbances of two different fluorescent quantum yield standards. The integrated fluorescence intensities were...
High field time-domain terahertz spectroscopy (TDS) is used to determine the time dependent transmission and the time-delay and optical-power dependent conductivity of a wafer of gallium arsenide (GaAs). Gallium arsenide is a direct band-gap semiconductor and has potential as a computer processor component. Analysis of the transmission of terahertz (THz)...
The spalting fungus Scytalidium cuboideum secretes a red pigment that produces naphthoquinonic crystals that are a photonic material candidate. The molecule can pack together in different configurations resulting in amazingly different optical properties. I developed a procedure (slowly evaporating the solvent) to preferentially grow two of these configurations, which have...
The equation of state for a fluid described by the Weeks-Chandler-Andersen (WCA) potential was solved to determine at what pressures and temperatures the fluid will theoretically freeze. A Monte Carlo (MC) algorithm was used to sample a system of 256 spheres for a set of thermodynamic averages to locate and...
Many biological processes are regulated by the presence and movement of cellular Ca²⁺ ions. The concentration of Ca²⁺ in a cellular environment is regulated by IP₃ sensitive channels that lie on the surface of a cell’s endoplasmic reticulum. Little is known about the macroscopic effects of intracellular Ca²⁺ activity, so...
In recent decades, the cell phone has provided a convenient form of long-distance communi-cation to the general public. Despite the technological improvements since, cell phones and their smartphone successors have suffered from a lack of clarity over a typical voice call, a result of their limited bandwidth. New phone services,...
Since the advent of graphene, research on 2D materials has exploded. Countless experiments have uncovered novel properties that emerge when different layered crystals are cleaved down to only a few atomic layers in thickness. The most popular of these non-graphene 2D materials is MoS2, a semiconductor which has been of...
Using a simple dry transfer process, I construct and characterize three nanoscale MoS2 devices using current-voltage curves, Raman spectroscopy, optical and atomic force microscopy. I compare these devices, the thinnest of which was few layer ( ≤ 10 nm) MoS₂ capable of showing photoconductance, with a current whose magnitude is...
Xylindein is an organic pigment derived from Chlorociboria aeruginascens and C. aeruginosa fungi that has shown promise as an organic semiconductor. Preliminary estimates of charge carrier mobilities (CCMs) on the order of 0.1 cm2/Vs were calculated from early tests on xylindein thin films, and photocurrents were also observed under laser...
Using a plastic bottle, we explore the capabilities of a reflective phase-only Spatial Light Modulator (SLM) in removing wavefront aberrations using a Zernike polynomial phase mask, with the modulators phase depth limited to 0.8π radians. Wavefront aberrations, which can be modeled with Zernike polynomials, distort image transmission through various optical...
Hall measurements can be made on the unstudied alloy, Sn₁-ₓCaₓSe to determine its electrical transport properties. The Sn₁-ₓCaₓSe samples were made by laser deposition into thin films and have a variable of calcium concentration x. These samples are approximately 250 nm in thickness, were grown at 366° C and are...
Gravitational wave (GW) astronomy is a key ingredient in confirming Einstein’s theory of General Relativity and showing how the universe sends ripples through spacetime, distorting distances between two points. The confirmation of high-frequency GWs observed by The Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015 was a breakthrough in our understanding...
The dynein molecule is a peculiar motor protein recognized for its unique stepping behavior. Sometimes it steps forwards. Other times it steps backwards. It has even been observed to occasionally shuffle by beginning a step with the same domain many times in row. These motions make dynein an interesting object...
Aging is known to be affected by many factors such as nutrition and exercise, and more studies are needed to understand the mechanisms of aging. Aging in flies shows many similarities with humans; therefore we study mechanisms of aging in flies as a model organism. Studying aging in flies requires...
We examine a discrete-time quantum walk with two-step memory for a particle on a one-
dimensional infinite space. The walk is defined with a four-state memory space analogous to the
two-state coin space commonly used in discrete time quantum walks, and a method is presented
for calculating the time evolution...
Type I collagen fibers, the connective tissue that makes up the human breast, can be easily manipulated by cells or other outside factors. In previous studies, the alignment of collagen has been associated with the beginning of metastatic cancer, possibly influencing cancerous cells to migrate from the tumor. In this...
Microelectrode array (MEA) dissolved-oxygen (DO) sensors were built and electrochemically tested in a solution of potassium ferricyanide. MEAs are becoming more popular as DO sensors because of their small size and capacity for simultaneous measurements with multiple recording sites. The ability to measure DO with multiple recording sites is useful...
A new class at Oregon State, PH 317: Experimental Physics, is designed to simulate a traditional laboratory research experience for undergraduate students. Several weeks of the class is devoted to Brownian motion experiments. Although this is a common topic for undergraduate lab classes, the experiment still needed some basic exploration...
Units and dimensions are seldom addressed formally in science classrooms, despite being one of the most fundamental and ubiquitous tools available to scientists. Even worse, science and engineering graduates are often moving into careers without fundamentally understanding units and their importance, leading to struggles in developing scientific literacy and to...
Exciton polaritons are quasiparticles composed of a quantum superposition of matter and light states that arises from the coupling of a standing wave photon and an exciton. This research has two primary objectives: to design and fabricate a Fabry-Perot microcavity system in which to produce exciton polaritons; and to show...
Detecting gravitational waves is a topic at the forefront of physics. The first gravitational wave was detected by LIGO in 2015. This wave had a frequency in the 10s of Hz. This project is focused on detecting gravitational waves on the nanohertz spectrum using a pulsar timing array. This array...
The scattering of optical rays by small spherical particles bears a strong resemblance to the
diffusion of fission neutrons in solid materials. This work explores the feasibility of
exploiting similarities between these two systems for the purposes of reactor component analysis, education, and outreach. After a brief overview of reactor-environment...
I construct and examine the properties of Lie and Clifford algebras which are used to describe certain types of particles. These algebras are then related to the traditional theory of division algebras. Quaternions are applied to these algebras and their properties are exploited to model physical properties of particles. The...
Gamma ray bursts are some of the brightest events in the entire observable universe. Since the late 1960’s, thousands of gamma ray bursts have been observed and they have been researched extensively. However, there are still many mysteries which remain unsolved. One such mystery is whether or not the viewing...
Crystal morphology and dimensionality of single-crystal semiconducting materials can have dramatic effects on the optical and electrical properties. Organic photovoltaic (OPV) materials and fluorinated graphene folds are two materials that show these dependencies. Anthradithiophene (ADT), is an OPV that can be functionalized with different side groups to form different crystal...
Crystals are solid materials with periodic and symmetric molecular patterns. The structure of a crystalline solid determines its properties, making it essential to study its structures. From the principle of minimum energy, a crystal will choose a structure with the lowest free energy F = U – TS. At low...
The current model for gamma ray bursts (GRBs) assumes that internal shocks are responsible for the emission of gamma-rays. Internal shocks occur when the fast expanding shell collides with the slowly expanding shells. The light curve of a GRB depends on the initial state and the expanding speed of the...
Carbon nanotubes are the subject of intense interest in virtually every field, from medicine to nano-scale electrical components. Multi-walled nanotubes exhibit a strong nonlinear response to high-field strength terahertz radiation. This research uses terahertz pulses with field strength exceeding 1 MV/cm generated by means of optical rectification utilizing a lithium...
Carbon nanotubes are the subject of intense interest in virtually every field, from medicine to
nano-scale electrical components. Multi-walled nanotubes exhibit a strong nonlinear response
to high-field strength terahertz radiation. This research uses terahertz pulses with field strength
exceeding 1 MV/cm generated by means of optical rectification utilizing a lithium...
A great variety of topologically protected defects exist in ordinary and exotic states of matter. Some of them are promising candidates for technological applications such as magnetic memory or quantum computers. Others possess some properties of elementary particles that could lead to potential applications in quantum fields. Nematic liquid crystals...
The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) is an international collaboration that seeks to use perturbations in the time of arrivals of pulsar signals to detect gravitational waves in the nanohertz range of frequencies. The 15-year data set will be released as of June 2023. It is a...
TiO₂ typically crystallizes into three polymorphs: brookite, rutile, and anatase. The phase selection problem in TiO₂ is the lack of understanding what conditions cause amorphous TiO₂ to crystallize into one of its three polymorphs during an annealing process. It has been recently shown that phase selection in TiO₂ is highly...
I investigate the feasibility of a micron-sized biosensor designed to measure neural activity. The circuitry of the biosensor is composed of graphene, some photodiodes, and a light-emitting diode. Many of these biosensors would be injected into a subject’s brain, and when powered by near-infrared light, they would glow in response...
An apparatus and method for calibrating planar laser induced fluorescence using a two-dye, two-color method was developed. A laser sheet was expanded from a 473 nm laser to excite dye solutions into higher energy states then fluoresced through spontaneous emission. The two fluorescent dyes selected for research and development were...
Different models show the effects of environmental decoherence on a quantum system
due to various environments of interest. One important quantity within these models is
the decoherence time, which tells us how quickly environments wash away the coherence of
local measurements. We can describe this effect as the quantum system...
The ability to focus light through strongly scattering materials is opening up exciting new avenues in many fields, such as optics, computer vision, biology, and medicine, which utilize light delivery and imaging techniques. Efficient, high resolution wavefront shaping and optimization methods are crucial to enabling this new capability.
In this...
Computational simulations of disks are becoming an important tool to predict the the evolution of protostars and disks to better understand the formation of planets. Past research has shown that the evolution of disks and their protostar can be altered through the interaction between gravity and hydrodynamic instabilities. We perform...
A method for determining bandgap energy using diffuse reflection is presented. The method uses bifurcated fiber optic cables to measure the diffuse reflection of diffusely reflective materials. The absorption spectrum is extrapolated from the diffuse reflection spectrum and used to determine the bandgap of powdered materials. The theory of nonspecular...
Terahertz (THz) frequencies of the electromagnetic spectrum have been underutilized when compared to neighboring microwave and infrared frequencies, largely due to the difficulties controlling and detecting these fields. In a step toward gaining control over THz frequencies, my advisor Dr. Yun-Shik Lee’s group experimentally demonstrated optical-pulse THz-control over a plasmonic...
The relationship between the index of refraction and the porosity of a material is that the index decreases with respect to the porosity. This property can be used to change the index of refraction of films which allows control of the reflection of the material. This is important because being...
Terahertz (THz) time-domain spectroscopy provides insight into electron dynamics in semiconductor heterostructures. High-field THz spectroscopy probes the excitonic nonlinear response of GaAs quantum well (QW) systems and enables the measurement of its coherent dynamics in the time-domain. Consequently, THz spectroscopy allows one to explore the fundamental properties of many-body interactions...
We measure the charging and discharging of two organic materials, PCBM and ADT-TES-F. These materials are studied through the noncontact method of particle trapping known as Optical Tweezers, where an IR laser is used to constrain the motion of a coated or noncoated silica sphere while its positional data is...
The calculation of interplanetary trajectories is a numeric problem which requires a high degree
of precision for the results to be accurate. A computer program was written for this project which
uses leapfrog integration combined with Newton’s method of iterative root finding to find ideal
interplanetary trajectories. Reasonable initial conditions...
We developed an integration-based line detection algorithm. Existing line detection methods such as the Hough Transformation (HT) and its variants are insensitive to image noise. The reason is that HT finds lines by calculating the gradient of the image and assumes that the region where the gradient is the steepest...