Increased physical activity (PA) in children has been linked to improved quality of life, as well as the establishment of life-long PA habits that lead to improved health outcomes. The literature suggests that children who participate in organized sport programs engage in more PA than children who do not. Notably,...
During 2016-2018, unprecedented aggregations of the colonial pelagic tunicate Pyrosoma atlanticum were observed in the Northern California Current (NCC). Pyrosomes are common in tropical and sub-tropical ocean waters, but little is known about their abundance, distribution, and trophic ecology in mid-latitude systems. To assess these factors, pyrosomes were collected during...
The purpose of this qualitative, phenomenological study was to explore the lived experiences of incarcerated women who participated in a service-learning program to help the homeless. Service-learning is effective pedagogy for involving students in civic engagement, and their involvement has been shown to increase the self-esteem of participating college students....
The infrared absorption spectra in the out-of-plane
bending (v₂) region of potassium nitrate were studied for
three phases. Several types of sampled were used: nujol
mulls, fused samples, and N¹⁴-N¹⁵ isotopic mixtures. The
existence of three of the reported polymorphic phases was
confirmed by the spectra. The transitions between phase...
The thermal degradation of structural materials is considered to be a key factor for evaluating the lifetime of current nuclear power plants. Ni-based and Fe-based alloys, such as 690, 625, 304, and 316, are widely used in nuclear industry as structural components due to the extraordinary corrosion resistance and mechanical...
The corrosion behaviors of carbon and stainless steels were investigated in supercritical CO₂ (sCO₂ ) containing H₂O and O₂ simulating conditions that exist in direct sCO₂ power cycle heat exchangers. Thermodynamic properties of CO₂-H₂O-O₂ systems related to the corrosion phenomena were determined using NIST software. The exposure tests of the...
New low enriched uranium (LEU) fuels are being developed for replacement of high enriched uranium (HEU) fuels in high power research reactors. U-Mo LEU plate fuels have been identified as a candidate for replacement of current HEU fuels. However, U-Mo fuels tend to exhibit accelerated swelling typically at fission densities...
The corrosion resistances of several alloys were investigated to optimize performance and cost in seawater and supercritical CO2 environments. Many alloys are prone to corrosion in seawater and/or supercritical CO2 containing impurity environments. Exposure and electrochemical experiments were conducted in both environments to evaluate alloys’ corrosion resistance. In seawater corrosion...
Using supercritical CO₂ (sCO₂) as a working fluid has increasingly gained attention in the energy industry. sCO₂ power cycles has various advantages, such as high cycle efficiency, compact turbomachinery, and potential zero CO₂ emission. Along with these benefits, materials degradation issues have also been emphasized in the last decade. Aqueous...
Glioblastoma is a malignant brain tumor that has extremely poor prognoses with a 5 year survival rate of less than 5%. The low survival rates of glioblastoma patients is attributed to glioblastoma cells being extremely resistant to radiotherapy and chemotherapy as well as being very invasive. We previously identified calpain...
Mechanical property degradation due to isothermal ageing is of potential concern for alloys based on the Ni-Cr binary system (e.g., Inconel 690, 625), particularly in nuclear power applications where component lifetimes can exceed 40 years. In the present research, the disorder-order phase transformation, which is the primary mechanism of ageing,...
The objective of this study was to evaluate the influence of cow age on grazing distribution relative to mountain riparian areas. In each of two years, sixty cow-calf pairs were stratified by age into the following treatments: 1) thirty first calf heifers (442 kg, body condition score (BCS)=4.5), and 2)...
The purpose of this study was to investigate the professional interaction
and interpersonal communication factors in the management of biomedical
instructional development projects which involved the use of electronic media.
Reference is made, repeatedly, in instructional development literature to
the need to include interpersonal communication skills in the education and...
The corrosion resistance of steels and nickel based alloys was investigated in supercritical CO2 (sCO2). Two types of experiments were conducted. The first set of experiments were conducted in a low temperature aqueous environment to simulate conditions that would exist in direct sCO2 power cycle low temperature heat exchangers. The...
In February 1994, EPA proposed to "refine" its carbon monoxide (CO) hot spot model,
CAL3QHC, to increase its accuracy and reliability. Currently, this proposal includes
using hourly meteorological data recorded at airports near the modeling sites instead of
the worst case conditions now recommended as a modeling default. The analysis...
A program, Color Choropleth Mapping System (CCMS), has
been developed to provide high quality color choropleth maps at
the Geography Department at Oregon State University. The program
operates interactively and is menu-driven. When developing the
software for mapping programs, programmers need to be aware of
cartographic theory, as well as...
In transboundary water resources policy and management situations, such as the governance of the Columbia River Basin, complex social, ecological, and economic factors seem to be in irreconcilable competition with one another. However, cooperative negotiation provides an outlet for entities and stakeholders to "expand the pie" and develop creative alternatives...
In 1987, Congress authorized a 5 year $150 million dollar research program called
the Strategic Highway Research Program (SHRP). SHRP was divided into four major
areas, including the asphalt research program. The asphalt research program was divided
into six major research contracts, one such contract, SHRP-003A was called Performance
Related...
Artificial collectives are useful for accomplishing tasks that require teamwork from multiple simple robots. Multiple robot and collective testbeds have been developed, yet none stay committed to leverage the local interactions, group size, and imperfect information assumptions that strengthen biological collectives. A review of the collective and multiple robot literature,...
The purpose of this study was to explore the current levels of physical activity among youth with disabilities using meta-analysis. The search identified 11 publications including 729 participants (age 4-20 yr). The overall effect size for 11 studies was Hedges g = 0.60 (SE = 0.18, 95% confidence interval [CI]...
This study examines dissolved rhenium (Re) as a function of water runoff using river samples from two contrasting watersheds, the Eel and Umpqua Rivers in the Pacific Northwest, USA. These watersheds share many key characteristics in terms of size, discharge, climate, and vegetation, but they have a 10-fold difference in...
The influence of vesicular-arbuscular mycorrhizae (VAM) on
populations of general taxonomic and functional groups of naturally-occurring
rhizosphere bacteria and actinomycetes associated with
roots of sweet corn (Zea mays var. rugosa) and subterranean clover
(Trifolium subterraneum L.) was assayed using selective media.
Sporangial production by Phytophthora cinnamomi was also used as...
This work explores the mechanical properties of single-phase niobium alloy C103 from room temperature to 600°C for the purpose of expanding safe uses of the material into new applications. The study utilizes a symmetrically notched triaxial tensile specimens to manipulate the internal stress field in order to observe the changes...
Commercial and public safety usage of Unmanned Aerial Vehicles in the National Airspace is currently restricted by federal regulation. The Federal Aeronautics Association is interested in modifying the restrictions; however, research is needed to study the human factor and required aptitude for a single human operating multiple UAVs. This Master’s...
This dissertation incorporates coalition formation and probabilistic planning towards a domain-independent automated planning solution scalable to multiple heterogeneous robots in complex domains. The first research direction investigates the effectiveness of Task Fusion and introduces heuristics that improve task allocation and result in better quality plans, while requiring lower computational cost...
Directed energy deposition and laser cladding technologies are suitable advanced manufacturing techniques for applying corrosion-resistant claddings to large carbon steel components. In this work, we clad 309L stainless steel wire onto carbon steel substrates and examine the effects of cladding parameters (laser power and travel speed) on metallurgical bonding, composition,...
The advent of supercritical CO2 as a new heat-exchange medium has seen strong interest from the power industry and the energy research field recently. It is advan- tageous in comparison with other heat-exchange cycles, as it can be operated safely at much higher temperatures and pressures, thus increasing the thermal...
Variations in heat treatments have significant effects on the microstructure of tool steels. For CPM-M4 tool steel, the changes in microstructure and mechanical properties were observed based off of variations in temperature. Five heat treatments with constant exposure time and variable austenitizing and tempering temperatures were performed on samples of...
This dissertation works towards determining the mechanisms driving the Mo isotopic composition of soils, and how these signals may be used to refine the use of Mo as a proxy of biogeochemical processes. The first step towards quantifying Mo fractionation in soils is to determine the mechanisms controlling Mo accumulation,...
Nickel (Ni)-based alloys with a high chromium (Cr) content are frequently employed in applications where elevated temperatures and/or corrosive environments are present due to their excellent corrosion resistance and mechanical properties. However, a gap exists around the formation, and kinetics of long-range order (LRO) Ni2Cr phase in both model binary...
This work explores the hypothesis that proton irradiation is a feasible alternative to simulate accelerated thermal aging for Ni2Cr long-range ordered phase formation within NiCr and NiCrFe alloys. In this study, various model alloys and commercial alloys 690 and 690+P (0.01 wt.% P) were subject to 2 MeV proton irradiation...
High purity niobium metal is used in the construction of superconducting radio frequency (SRF) cavities in superconducting particle accelerators, such as the Large Hadron Collider (LHC) at CERN or the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The usual method for characterizing the impurities in this niobium, the...
Human-robot teams involve humans and robots collaborating to achieve tasks under various environmental conditions. Successful teaming requires robots to adapt autonomously in real-time to a human teammate's state. An important element of such adaptation is the ability for the robot to infer the tasks performed by their human teammates. Human-robot...
Disaster response and surveillance operations will increasingly incorporate Unmanned Aerial Vehicles (UAV)s due to their cost-effectiveness and maneuverability. This trend has driven the research on small-sized quadcopters for varying indoor applications. Small-sized quadcopters' payload and computational capacity limit the usage of complex vision-based collision avoidance algorithms that are employed by...
Dust deposition on ecosystems with highly weathered soils may provide vital rock-derived nutrients that maintain ecosystem productivity. Because of the difficulties in measuring temporally and spatially heterogeneous dust deposition over ecologically meaningful timescales, evaluations of the spatial variability in dust deposition are extremely rare. In the Luquillo Mountains of Puerto...
Demanding task environments (e.g., supervising a remotely piloted aircraft) require performing tasks quickly and accurately; however, periods of low and high operator workload can decrease task performance. Intelligent modulation of the system’s demands and interaction modality in response to changes in operator workload state may increase performance by avoiding undesirable...
Duplex stainless steels (DSS) are an attractive potential material in nuclear power generation systems due to an excellent combination of corrosion resistance, strength, toughness, and affordability. Thermal embrittlement caused by phase instability in the temperature range of ~300-550°C severely limits the service temperature of DSS. The rate of embrittlement varies...
Collective migration in animal groups is often guided by distributed leader agents that influence their peers by modulating their motion behaviors. Distributed leadership is a promising navigation strategy for artificial swarms, but designing the leaders’ controllers is difficult due to the swarm’s collective emergent behaviors. The presented research formulates a...
Mountain search and rescue is a vital form of emergency response to assist people in austere environments (e.g., extreme terrain, poor weather). Volunteer mountain search and rescue teams in the United States have begun adopting consumer- grade unmanned aerial vehicles to assist a variety of tasks (e.g., search, resource delivery);...
The aim of this study is to explore how women who identify as both active, believing Mormons and as feminists negotiate the contradictions between an ideology that values equality (feminism) and a religion that values patriarchy (Mormonism). Data were gathered through recorded and transcribed interviews with women who identify as...
The monolithic (plate type) Uranium 10 wt.\% Molybdenum (U-10Mo) fuel system is promising for a variety of applications, most notably for the replacement of highly enriched uranium (HEU) fuels with low enriched uranium (LEU) fuel in United State High Performance Research Reactors (U.S. HPRRs).
Phase transformations and secondary phase formation...
Cephalopod-inspired soft robot arms have been studied as a new type of manipulator. These arms have been proposed for reach and grab tasks, underwater locomotion via swimming and walking, and robotic surgery. However, the capabilities of existing soft arms are limited to simple motions and light loads. Arm design has...
Oxide growth is a common phenomenon on aluminum alloy cladding surfaces in nuclear research and test reactors. Without better understanding of oxide growth, excessive oxide build up on the cladding surface reduces heat transfer capability from fuel to coolant and causes safety concerns due to the potential cladding rupture or...
In order to determine how contaminants from pharmaceutical, agriculture, and industry will move through groundwater systems, it is imperative to further our understanding of the relationship between physical, biological, and chemical properties of aquifers and transport and transformation of these products. Several studies have explored how heterogeneities in groundwater systems...
Molybdenum is an essential component of biogeochemical cycling, most notably as a component of the nitrogenase enzyme used in biological nitrogen (N) fixation. While the important role of phosphorus (P) in limiting N fixation in ecosystems has been well documented, occurrence and prevalence of molybdenum (Mo) limitation is largely unknown....
Molten salts have been targeted as a promising coolant for next generation reactors due to their high boiling point, heat capacity, and thermal conductivity. Despite these benefits, molten salt systems present unique materials compatibility issues, highlighted by the aggressive corrosion attack and dealloying typically seen on materials in these environments....
Ecosystem nitrogen (N) supply strongly influences the availability and cycling of other essential nutrients in temperate forests, especially calcium (Ca). Short-term additions of N that exceed ecosystem demands often increase dissolved nitrate fluxes and decrease soil pH, which can stimulate soil Ca loss. However, the long-term effects of high N...
The purpose of this study is to explore the factors that led to the move to include non-need aid in community college institutional financial aid policies. The following questions guided the research: (1) What meaning do those involved in the
formulation of institutional financial aid policy at community colleges give...
Fort Hoskins, located in Kings Valley, Oregon, was established in 1856 as one of
three forts to monitor the newly created Coastal Indian Reservation. Companies U and F
of the 4th Infantry were assigned to Fort Hoskins until 1861 when they were transferred
to the East with the outbreak of...