Pacific Northwest temperate rainforests are anticipated to experience increasingly frequent and severe wildfires in the foreseeable future due to climate change, increased fuel loads, and deforestation. Soil, underlying these forests, is the largest terrestrial carbon (“C”) reservoir. Fire disturbance influences soil C persistence, the timeframe and magnitude of which remain...
Volatile organic compounds (VOCs) play an integral role in climate change and as a carbon source for organisms living in a marine environment. These compounds have many sources, but the impacts of biogenically produced VOCs is not fully known. Phaeodactylum tricornutum was studied under axenic ideal growth conditions to determine...
Microplastics (<5mm) are a ubiquitous environmental pollutant that have the potential to cause significant harm in many fish species. Therefore, understanding the quantities at which they are being consumed by living organisms is crucial for characterizing risk. There are currently gaps in the microplastic literature regarding microplastic data from finfish...
Solutions to Einstein's equations are usually found by considering ideal, simplified models. However, if the real world always matched ideal physics models, then farmers would milk black and white spheres. To combat this, Regge calculus was developed as a numerical approximation scheme for general relativity. In Regge calculus curved manifolds...
The following text is a consolidated version of the Cakrasaṃvara Samādhi, along with the Guru Maṇḍala, Sūryārgha, Pañcagavya, Guru Pādārgha, Kāybhaḥ Pūjā, Rahasya Pūjā, Kalaśa Pūjā, Vāruṇī Pūjā, Bali Pūjā, Kīgaḥ Tine, and a Pātra Jñāna. The Cakrasaṃvara Samādhi, as has been discussed above, is the primary pūjā and sādhanā...
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...
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...
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...
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...
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...
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...
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...
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...
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...
The United Nations Food and Agriculture Organization (FAO) in the State of World Fisheries and Aquaculture 2018, has observed that the trend of the world’s marine fish stocks has been overexploited, depleted, and has exhibited decreasing trend within the fraction of biologically sustainable levels. While these situations are an alarming...
Top predators play important roles in regulating communities and ecosystem processes in freshwater ecosystems. In the headwater stream network, it is crucial to understand the interspecific interaction between multiple predators. In Oregon forested ecosystems, Coastal Giant Salamander (Dicamptodon tenebrosus) and cutthroat trout (Oncorhynchus clarkii) are the top predators in many...
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...
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...
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...
Succinate dehydrogenase (Sdh) inhibitor fungicides, such as boscalid, are effective for the management of gray mold caused by the fungal pathogen Botrytis cinerea. Unfortunately, resistance to boscalid was common among isolates of the pathogen from small fruits grown in Oregon. Boscalid-resistance is commonly associated with mutations in Sdh, especially in...
Endophytes, foliage inhabiting fungi, are an unexplored source of fungal biodiversity and a potential resource for the production of bioactive natural products. In this research, leaf tissues from the species Arbutus menziesii, Rhododendron macrophyllum and the genus, Ilex and Salix were collected for the isolation of endophytic fungi. Fungal extracts...
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...
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...
Bacterial endophytes have the potential to confer benefits to Douglas-fir ( Pseudotsuga menziesii ), for instance drought tolerance. Bacterial endophytes originating from seeds are especially important. This is because seed endophytes are more likely to be the first endophytes to get established within the young host plant. The goals of...
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...
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...
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...
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...
Polycyclic aromatic hydrocarbons (PAHs) are a class of contaminants ubiquitous in the environment and result from the incomplete combustion of fossil fuels. Many PAHs have been identified as procarcinogenic, and are metabolized to form DNA adducts; however, other mechanisms also may contribute to toxicity and help explain differences in toxicity...
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...
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,...
The details of the 1700 Cascadia Subdction Zone earthquake and tsunami can be better constrained using data from tsunami sand sheets, provided knowledge of the waveform, estuary geometry and bed roughness controls on the deposition pattern of the sand sheet. In this study, we use the hydrodynamic and sediment transport...
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...
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 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...
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...