The first objective of this paper is to prove the existence and uniqueness of global solutions for
a Kirchhoff-type wave equation with
nonlinear dissipation of the form Kuⁿ + 𝑀(|𝐴¹/²𝑢|²)𝐴𝑢 + 𝑔(𝑢')=0 under suitable
assumptions on 𝐾, 𝐴, 𝑀(⋅), and 𝑔(⋅). Next, we under some growth conditions on the nonlinear...
This thesis will cover work that I have completed relating to the field of terahertz (THz) science. My work has consisted of generating tunable, narrowband THz pulses in a table-top optical setup and using both narrow- and broadband THz pulses to study various material systems. Broadband THz pulses were used...
This thesis will cover my work relating to the developing field of terahertz (THz) science and technology. It will present experimental and theoretical studies investigating the optical and electrical properties of various material systems using novel THz imaging and spectroscopy techniques. Due to its low photon energy, THz imaging and...
Nitrosomonas europaea (ATCC19718) participates in the biological removal of nitrogen from wastewater by oxidizing ammonia to nitrite, the first step in nitrification. This bacterium is sensitive to heavy metals (Zn²⁺, Cd²⁺, Cu²⁺, and Hg²⁺) and cyanide, compounds commonly encountered in wastewater treatment plants. Therefore, we characterized physiological and transcriptional responses...
The continued development of organic semiconductor materials relies on an understanding of the relationship between optoelectronic properties, molecular structure, and molecular interaction. Several detailed studies of electronic properties in functionalized polyacene materials are presented. A computational model which allows the extraction of charge generation and transport properties from experimental data...
Magnetic thin films have potential to improve devices such as on-chip inductors, and enable new technologies such as magnetic random access memory (MRAM).
The use of magnetic cores in on-chip inductors is typically limited to applications well under 1 GHz. At higher frequencies, the performance of the magnetic core is...
In the past decades, femtosecond stimulated Raman spectroscopy (FSRS) has been gaining tremendous popularity in fundamental sciences stemming from chemistry to biology. It is capable of capturing both equilibrium and non-equilibrium structural information across a broad range of timescales with simultaneously high temporal and spectral resolutions. Femtosecond transient absorption spectroscopy...
Low carbon steels (LCS) due to their high strength-to-cost ratio are one of the most ubiquitous materials used for a wide range of applications, including but not limited to automotive, construction, and transportation. However, the low corrosion resistance of LCS in neutral, acidic, or saline environments limits its utilization and...
Femtosecond stimulated Raman spectroscopy (FSRS) is an ultrafast vibrational technique which allows rapid collection of Raman spectra with simultaneously high temporal and spectral resolution. With the recent development of FSRS methodology, three FSRS techniques (conventional, tunable, and anti-Stokes) have been implemented in our laboratory to dissect the excited state structural...
To obtain a mechanistic understanding of the chemical processes, techniques that offer a frame-by-frame visualization of molecular structure during a reaction are of vital importance. Numerous efforts and advances have been made in order to acquire such vivid molecular “movies”, especially in the electronic excited state. Ultrafast molecular spectroscopy method...
Understanding the impact of inter-molecular orientation on the optical proper-ties of organic semiconductors is important for designing next-generation organic (opto)electronic and photonic devices. However, fundamental aspects of how various features of molecular packing in crystalline systems determine the nature and dynamics of excitons have been a subject of debate. Toward...
New acceptor-type graphite intercalation compounds (GICs) containing perfluoroalkyl anions have been synthesized by using both chemical and electrochemical methods and characterized by elemental and thermogravimetric analyses. Investigation into these graphite intercalation compounds can provide novel materials and a detailed understanding of their properties.
GICs of composition Cx[FB(C₂F₅)₃]·δF are prepared for...
TiO2 is a versatile wide bandgap transparent semiconducting oxide with three well known polymorphs: Anatase, Rutile and Brookite. These crystal structures are desired for many industrial applications mainly for their photocatalytic activity, oftentimes in thin-film form. Thin-film crystalline polymorphs of TiO2 are often made by physical vapor deposition on a...
We demonstrate terahertz (THz) imaging and spectroscopy of single-layer graphene deposited on an intrinsic Si substrate using THz time-domain spectroscopy. A single-cycle THz pulse undergoes multiple internal reflections within the Si substrate, and the THz absorption by the graphene layer accumulates through the multiple interactions with the graphene/Si interface. We...
We demonstrate time-resolved terahertz transmission ellipsometry of vertically aligned multi-walled carbon nanotubes. The angle-resolved transmission measurements reveal anisotropic characteristics of the terahertz electrodynamics in multi-walled carbon nanotubes. The anisotropy is, however, unexpectedly weak: the ratio of the tube-axis conductivity to the transverse conductivity, sigma[subscript z]/sigma[subscript xy] [similar or equal to]...
This report describes research activities in the Oregon State University School of Engineering during the school year 1960-61. Projects are listed according to the department wherein the work is conducted. Advanced degrees in engineering, which were conferred at the June 1961 Commencement, are listed in a separate section along with...
The consumption of cruciferous vegetables is associated with several health benefits, including cancer prevention. Many of these benefits are attributed to the phytochemical, sulforaphane (SFN), which is derived from cruciferous vegetables such as broccoli and broccoli sprouts. These vegetables contain glucoraphanin (GFN), SFN’s precursor, which is converted to SFN by...
There is an emerging interest in developing wearable electronics as a platform, which
provides the flexibility of a wearable while maintaining its promising functionality as smart textiles. Metal-halide semiconductors are attractive materials with tunable optical and electrical properties. Researchers have widely studied and applied it for advanced
photonics and optoelectronic...
Root-knot nematodes (Meloidogyne spp.) are one of the most important global plant pathogens. Recent innovations in molecular techniques have allowed increased study of this important pest, including the ability to investigate associated microbiomes. This study used 16S rDNA metagenomic sequencing to characterize the microbiome of Meloidogyne hapla, the northern root-knot...
Global efforts to support non-uranium approaches for 99Mo production, due to the proliferation risks associated with 235U fission-based production methods, have recently taken huge strides towards fruition. Several linear accelerator-based methods are currently in late-stage development that can produce low specific activity 99Mo from enriched 98/100Mo targets. The development of...
Targeting the epigenome, including the use of histone deacetylase (HDAC) inhibitors, is a novel strategy for cancer chemoprevention. Sulforaphane (SFN), a compound found at high levels in broccoli and broccoli sprouts, is a potent inducer of Phase 2 detoxification enzymes and inhibits tumorigenesis in animal models. SFN also has a...
Interactions between sediment bacteria and available phosphate
necessary for algal production in a eutrophic lake were studied.
Twenty percent of the organisms isolated solubilized phosphate forms
such as CaHPO₄, Ca₃(PO₄)₂, FePO₄, Mg₃(PO₄)₂ and Al₂(PO₄)₂.
Solubilization of phosphates occurred under conditions of aerobic
growth.
Upon quantitative analysis, some isolates were capable...
Melanocytes are dendritic, pigment-producing cells located in the skin and are responsible for its protection against the deleterious effects of solar ultraviolet radiation (UVR), which include DNA damage and elevated reactive oxygen species (ROS). They do so by synthesizing photoprotective melanin pigments and distributing them to adjacent skin cells (e.g.,...
Crystals of an incongruent-melting compound, Ba₃MgSi₂O₈, were grown by the flux method and its structure was determined by single crystal X-ray diffraction methods. Ba₃MgSi₂O₈ crystallizes in trigonal space group P-3[bar]m1 with a = 5.6123(3) Å, c = 7.2667(9) Å and Z = 1. Eu²⁺ ions prefer one crystallographic Ba site...
Part I: Plasmonic color filters can be manufactured at lower cost since they can be fabricated in single lithographic process step as compared to Fabry-Perot based filters. In addition, they have narrow passband making resolving sharp features in sample spectrum possible. Due to these benefits, in this thesis, Plasmonic color...
Dietary nitrate (NO3-), consumed primarily from leafy green and root vegetables, lowers blood pressure, improves vascular function and aerobic exercise performance. This performance-enhancing effect of nitrate supplementation is largely attributed to the increased bioavailability of the signaling molecule, nitric oxide (NO). Nitric oxide is a ubiquitous free radical signaling molecule...
Acute lymphoblastic leukemia (ALL) encompasses a spectrum of lymphoid progenitors that have undergone malignant transformation and clonal proliferation at various stages of differentiation. Some cases of ALL have been documented to have prenatal origins and in particular neonatal exposure to various environmental pollutants is associated with increased disease risk, including...
Glutathione (GSH) is the predominant low molecular weight thiol antioxidant
in liver tissue. GSH plays an important role in maintaining the intracellular thiol redox
ratio as well as detoxification of electrophiles and xenobiotics. Aging leads to a significant decline (35%; P ≤ 0.05) in hepatocellular GSH levels. Using young (2-4...
Low-dimensional electronic materials offer a platform to observe biological processes with unprecedented spatial and temporal resolution. Carbon nanotubes (CNTs) are the closest physical analog to an ideal 1D system and can be scaled and integrated into multiplexed electronic circuitry. The molecular structure of a CNT is also biocompatible, making them...
The optical response of metallic structures is dominated by the dynamics of their free electron plasma. Plasmonics, the area of optics specializing in the electromagnetic behavior of heterogeneous structures with metallic inclusions, is undergoing rapid development, fueled in part by recent progress in experimental fabrication techniques and novel
theoretical approaches....
The cocondensation reactions of molybdenum trioxide vapor with
tetraalkoxysilanes, trimethylalkoxysilanes, and hexamethyldisiloxane
at -196°C were investigated. The products from the metal vapor
reactions of tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane
were characterized as molybdenum(VI)dioxodialkoxy compounds. The isolated compounds were found to be polymeric in the
solid state by bridging through alkoxide groups....
Phytochemicals from cruciferous vegetables, such as broccoli, contain a multitude of bioactive compounds that prevent and suppress cancer and promote optimal health. Some of the health promoting effects of cruciferous vegetables are attributed to a class of compounds known as isothiocyanates (ITCs), a potent nuclear factor erythroid 2–related factor 2...
Metabolomics has recently gained momentum in biomolecule research and complements the genomics and proteomics research space. Metabolomics strives to detect, identify, and quantify all metabolites present in biological samples. In particular, biomolecular analysis using ultra-performance liquid chromatography combined with mass spectrometry (UPLC-MS) has become increasingly important for metabolomic analyses. Similarly,...