An important improvement in the area of reactor core neutronic modeling is the development and use of the methods based on "quasi-diffusion" (QD) low-order equations. This family of methods takes into account the transport exactly using "functionals" computed by solving transport equations, and is amenable to solution with a variety...
We investigate several aspects of the numerical solution of the radiative transfer
equation in the context of coal combustion: the parallel efficiency of two commonly used
opacity models, the sensitivity of turbulent radiation interaction (TRI) effects
to the presence of coal particulate, and an improvement of the order of temporal...
The most widely used and versatile medical radioisotope today is technetium-99m. Roughly 30 million people depend on this radioisotope for diagnostic procedures each year, and this demand is expected to grow. Although there are numerous ways of procuring this isotope, the most common and most practical, for reasons to be...
Antineutrino detectors could provide a valuable addition to current safeguards
regimes. Antineutrinos are an attractive emission to monitor due to their low
interaction cross-section that prevents them from being shielded and the dependence
of their spectrum on the power level and isotopic content of a reactor core. While
there are...
In this dissertation, we derive and implement a new transport-diffusion hybrid algorithm for solving thermal radiative transfer (TRT) problems. Using the method of nonlinear elimination (NLEM), the TRT system of equations can be written in terms of a transport equation with the absence of scattering and a diffusion equation. The...
The implementation of advanced hybrid (Monte Carlo/Deterministic) transport methods for realistic test problems has been a challenge due to the overhead efforts associated with interfacing a solution generated by a deterministic solver with a Monte Carlo based radiation transport code. In this work, with the help of Transpire, Inc., a...
Circulating fuel reactor (CFR) kinetics are characterized by delayed neutron precursor (DNP) drift in addition to the neutronic and thermal hydraulic phenomena typical of other reactor types. This environment can be computationally challenging to model, given that the multiphysics phenomena generally have non-linear interdependencies requiring the use of iterative solution...
In this dissertation, we attempt to overcome the "curse of dimensionality" inherent to radiation diffusion kinetics problems by employing a novel reduced order modeling technique known as proper generalized decomposition (PGD). After verifying a proposed PGD algorithm and associated solvers through various tests, we explore its performance for computing reduced-order...
Human cathelicidin antimicrobial peptide (CAMP/LL-37) is a cationic antimicrobial peptide that is widely expressed by myeloid and epithelial cells at the human-environment interface. It possesses broad spectrum antimicrobial capacity against bacteria, fungi and viruses. In addition to its direct antimicrobial activity, CAMP/LL-37 also attracts and recruits monocytes, neutrophils and other...
We spatially discretize the Sn transport equation using the high-order (HO) discontinuous finite element method (DFEM) on HO meshes. Previous work provided a proof-of-concept for this spatial discretization method in X-Y geometry. Included in the present work, we derive a spatial discretization for the Sn transport equation in both X-Y...
Transcriptomics and gene expression profiling enables the elucidation of the genetic response of an organism to various environmental cues. Transcriptomics enables the deciphering of differences between two closely related organisms to the same environment and in contrast, enables the elucidation of genetic responses of the same organism to different environmental...
This research details laboratory assessment of bacterial hydrophobicity, variations in bacterial adhesion properties with growth and extended starvation as well as extension of this assay to colloidal hydrophobicity measurement. Hydrophobicity is an integral component of surface interactions and has been studied extensively for its role in a number of engineering...
We identified and evaluated a phytoseiid predator as a biological control agent of multiple spider mites pests that occur in ornamental nurseries. When comparing species, Neoseiulus fallacis (Garman) had a wider prey range than Galendromus occidentalis (Nesbitt), a higher probability of overwintering than Neoseiulus califomicus McGregor and was equally or...
If P is an integer polynomial denote the degree of P by ∂(P) and let H(P) be the maximum of the absolute value of the coefficients of P. Define Λ(P)=2[superscript ∂(P)]H(P) and for a fixed prime p let C[subscript p] denote the completion of the algebraic closure of the p-adic...
The primary goal of this dissertation is to improve the quality of nuclear data available to the nuclear science community. We propose to accomplish this by applying machine learning algorithms to the large number of available benchmark experiments and simulations, with the goal of determining which nuclear data have strong...
In order to address the energy needs of developing countries and remote communities, Oregon State University has proposed the Multi-Application Small Light Water Reactor (MASLWR) design. In order to achieve five years of operation without refueling, use of 8% enriched fuel is necessary.
This dissertation is focused on core design...
Ion therapy has long been investigated as a potential modality to improve cancer treatments beyond what is currently feasible with photon irradiations. Ions offer both a physical and biological advantage over photons. The physical advantages are well understood, ions deposit their maximum dose at defined penetration depths, allowing for minimal...
Nearly 3000 juvenile Chinook (Oncorhynchus tshawytscha) and coho (O. kisutch) salmon captured in nearshore waters off the coasts of Washington and Oregon from 1999-2004 were tested for infection by Renibacterium salmoninarum, Nanophyetus salmincola, and skin metacercariae. First, three quantitative PCR primer/probe sets were compared for detection of R. salmoninarum; amplification...
Citizen science is a term broadly used to describe activities that typically involve the public in the process, methods, and standards of scientific research with the aim of advancing scientific knowledge or application. Engagement in citizen science for project and program volunteers is influenced by much more than an individual’s...
Considerable controversy exists about how fish assemblages are
organized. I explicitly took fish movement into account while I
studied the effects of disturbance, habitat complexity, and predation
at different times of the summer to understand the major factors
influencing assemblage structure in a high desert Oregon stream. The
effects of...
Within the past several years the technology of high-throughput sequencing has transformed the study of biology by offering unprecedented access to life's fundamental building block, DNA. With this transformation's potential a host of brand-new challenges have emerged, many of which lend themselves to being solved through computational methods. From de...
State-of-the-art personal robots need to perform complex manipulation tasks to be viable in complex scenarios. However, many of these robots, like the PR2, use manipulators with high degrees of freedom. High degrees of freedom are desirable from a functionality standpoint, but make the learning task more difficult by adding a...
Manufacturing process design (MPD) represents a design-oriented approach to manufacturing engineering. In this dissertation, Haynes 230 (H230), a solid solution-strengthened Ni-based superalloy, was chosen to meet the material requirements of a microchannel solar receiver (MSR) needed to increase the efficiency and reduce the cost of solar thermal power generation. An...
E8,E10-dodecadien-1-ol, the primary component of the female sex pheromone of codling moth, Cydia pomonella L., has no attraction to male Oriental fruit moth (OFM), C. molesta (Busck). However, this compound when added to the OFM pheromone blend of Z8-dodecenyl acetate (85.5%), E8-dodecenyl acetate (5.5%), and Z8- dodecen -1 -ol (9.0%),...
High temperature microchannel heat recuperators (HTμRs) offer an efficient means of improving reactor process thermal efficiency by offering smaller form factors due to increased heat transfer surface area density and volumetric heat transfer rate over traditional heat exchanger designs. To date, HTμRs face cost and reliability challenges. In this work,...
Advances in plant construction within the energy and chemical process industries require inexpensive process intensification (PI) technology as a means to reduce plant size for enabling modular construction. One form of PI is microchannel process technology where arrays of microchannels, having hydraulic diameters on the order of 0.1 to 1...
This work investigates the in-tube condensation of low global warming potential (GWP) zeotropic refrigerant mixtures R448A, R450A, R452A, R454B and R454C. These refrigerants have been proposed for a wide range of commercial heating, ventilation, air-conditioning applications, but their heat and momentum transport phenomenon were not well understood. Thus, in this...
Transport phenomena specially the ones that occur in the various engineering disciplines such as tissue engineering and natural environment are often complex to analyze mostly due to the dynamic and geometric complexities; as such, they have been the subject of an active and intense area of research in past decades....
Quantification of macroscale transport phenomenon in microfluidic systems is important to many science and engineering disciplines. In part, this is because fully resolved solutions to microscale balance laws over large domains are out of reach with current computational technology. Additionally, engineers are most often interested in some upscaled quantity and...
The conventional advection-dispersion equation cannot adequately describe all processes driving
solute transport in heterogeneous systems. This dissertation focuses on the individual influences
of both chemical (Chapter 2) and physical processes (Chapters 3 and 4) which affect
solute transport. In Chapter 2 we analyzed uranium transport in natural sediment using the...
The Transient Reactor Test facility (TREAT) at Idaho National Laboratory (INL) is a unique reactor capable of stressing test fuel during a power pulse transient. TREAT fuel is composed of high enriched uranium (HEU) heterogeneous fuel; microscopic UO₂ fuel grains with an average radius of 10 μm are randomly distributed...
The study outlined in this dissertation elucidate the thermal and structural properties of ZrB2 based ceramics as choice materials for high temperature applications. Thermal properties were investigated to improve understanding on aspects that are affected by point defects and impurities at nanoscale and electron level using a combination of lattice...
The goal of this project was to pave the way for more data-driven decision making when considering safety within Nuclear Engineering by proving the concept of new and innovative accident scenario modeling techniques for the analysis of the economics of nuclear safety margins. To do this, a simple, if extremely...
How can end users efficiently influence the predictions that machine learning systems make on their behalf? Traditional systems rely on users to provide examples of how they want the learning system to behave, but this is not always practical for the user, nor efficient for the learning system. This dissertation...
Characiform fishes form one of the most diverse freshwater fish clades in the world. Comprising more than 2000 species and distributed primarily in South America and Africa, characiforms vary dramatically in their ecomorphology. However, the evolutionary processes responsible for the immense ecomorphological diversity remains unknown. Recently, a study postulated that...
The timing of two events in the early life history of coho salmon--emergence from
the gravel and entry into the ocean--is presumed to have evolved to ensure maximum
survival during these transition periods. Anthropogenic disturbances may disrupt the
timing of these events to the detriment of salmon populations.
Multivariate analyses...
Airborne discrete-return lidar is an active remote sensing technology capable of obtaining accurate, fine-resolution three-dimensional measurements over large areas. Discrete-return lidar data produce three-dimensional object characterizations in the form of point clouds defined by precise x, y and z coordinates. The data also provide intensity values for each point that...
In the midst of the sixth mass extinction, understanding wildlife disease spillover is critical to maintaining protected wildlife areas. Studying ecoimmunology and wildlife disease ecology helps to understand immune and disease traits in an ecological context, which is invaluable in preventing pathogen spillover between livestock and wildlife. To investigate this...
The neurohypophysial peptide system is involved in modulating a
variety of physiological, neurological, and behavioral responses in
vertebrates. The principal forms of these peptides in non-mammalian
tetrapods are vasotocin (VT) and mesotocin (MT). The studies described
in this thesis used pharmacological, molecular, and biochemical
techniques, along with phylogenetic analyses, to...
Partitioning of trivalent actinides (in particular, americium and curium) from the
fission produced light lanthanides is a major concern of used nuclear fuel reprocessing for
the purposes of waste disposal. Several solvent extraction processes have been developed
to address these chemically difficult separations. The historically employed TALSPEAK
Process utilizes di-2-ethylhexyl...
In this dissertation, time-based signal processing techniques and their applications in oversampling and noise-shaping data converters are examined. These techniques demonstrate the ability to shift the burden of high performance analog circuits from the compressed voltage-domain to the augmented time-domain. First, the potential of high order noise-shaping and phase-domain feedback...
Relative lifetimes, and the closely related quadrupole moments (Q[subscript]i values), of the
six superdeformed (SD) bands in ¹⁹³Hg and the yrast SD band in ¹⁹²Hg were determined
by a Doppler-shift attenuation method measurement. The experiment was performed
using the Gammasphere array and Lawrence Berkeley National Laboratory's 88-inch
Cyclotron. The Q[subscript]i...
The studies presented here use the B- to Z-DNA transition and Z-DNA
crystallization as model systems to determine the contribution of solvent interactions to
macromolecular structures. The substituent groups of naturally occurring and modified
nucleotide bases affect the hydration and thus the stability of right-handed B-DNA and
left-handed Z-DNA. The...
Chlamydia is an obligate intracellular bacterial pathogen that causes a variety of disease in animals and humans worldwide. Veterinary chlamydial pathogens can lead to chronic infections and serious consequences that result in millions of dollars of losses in animals and resources in the agricultural industry in countries that rear ruminants....
The atomic solid state energy (SSE) scale is introduced as a tool for inorganic materials design. The SSE scale is obtained by assessing an average electron affinity (EA) (for a cation) or an average ionization potential (IP) (for an anion) for each atom using data from compounds having that specific...
Recent state and national standards have increased the interest in engineering at the K-12 level. Science standards, in particular, have begun to make the case for including engineering throughout the K-12 scope of study. Despite the increased attention to engineering, the characteristics and uniqueness of the field of engineering are...