Herbs have been used for many centuries in diverse civilizations for the treatment of heart disease. Only a few natural supplements claim to have direct cardiovascular actions including hawthorn (Crataegus spp.) and berberine derived from the Berberidaceae family. Several different studies indicate important cardiovascular effects of hawthorn and berberine. For...
OBJECTIVES: Secondary caries is the most common reason for composite restoration replacement and usually forms between dentin and the filling. The objective of this study was to investigate the combined effect of cyclic loading and bacterial exposure on bacterial penetration into gaps at the interface between dentin and resin composite...
The AAPD recommends placement of dental pit and fissure sealants on surfaces that are high risk or that already exhibit incipient carious lesions. Protection provided by sealants may be enhanced by the addition of ion-releasing, anti-microbial filler particles of bioactive glass.
Objective: We prepared novel dental pit and fissure sealant...
Tooth decay in the form of dental caries and cavities is estimated to be among the most common health conditions globally, with treatment of these oral diseases resulting in a massive, world-wide economic burden. The cause of this demineralization of teeth is rooted in the action of complex microbial biofilms...
Microalgae has been under careful consideration as a sustainable feedstock for renewable fuel recently due to its year round production with high energy yields per unit area, reduced need for arable land, water treatment benefits with nutrient cycling, and minimal competition with the food industry. Despite of all these advantages,...
Accommodating motor vehicles that are turning (left or right) at signalized intersections requires a careful understanding of the safety and efficiency of design and operational variables. Turning vehicles are the primary collision risk for non-motorized road users at signalized intersections. When turning movements need to be controlled, proper driver response...
Since bulk p-CuO/n-ZnO heterocontacts were first proposed for gas detection, rapid development has taken place in improving the overall functionality of these structures. While bulk heterocontacts have been shown to exhibit desirable sensitivity and selectivity characteristics, these devices suffer from innate diffusion and ZnO/CuO connectivity drawbacks that limit their effective...
Global warming problem is becoming an increasingly important environmental concern and CO₂ is considered as the major cause of global warming. Among various methods of CO₂ utilization, conversion of CO₂ to value added chemical products is the most attractive. In this study, a microscale-based corona reactor is introduced for reduction...
Poor material utilization is inherent to conventional manufacturing processes, leading to high material waste and machining times. Additive manufacturing processes attempt to solve this issue by allowing production of near-net shapes, but the processes may be too expensive or infeasible. By leveraging both processes in a single part, the waste...
Recent advancements in joining operations and additive manufacturing now allow complex metal parts to be built up from raw materials, as opposed to being machined down from solid blocks. This not only opens up the design space, but also allows for much more efficient manufacturing. By decomposing a complex part...
Due to significant lipid and carbohydrate production as well as other useful properties such as high production of useful biomolecular substrates (e.g., lipids) and the ability to grow using non-potable water sources, algae are being explored as a potential high-yield feedstock for biofuels production. In both natural and engineered systems,...
Coral reefs, found in tropical regions, are renowned for their rich biodiversity and their contributions to ecological, cultural, and economic aspects worldwide. The success of coral reefs hinges on the symbiotic partnership between corals and their dinoflagellate algae, from the family Symbiodiniaceae. The algae reside within the coral host’s gastrodermal...
The effects of steel reinforcement, chloride-induced corrosion initiation, cracking and delamination on the electrical resistivity measurements using the Wenner probe technique were studied experimentally on custom-designed reinforced concrete slabs. Investigation parameters included (1) probe configurations with respect to rebar mesh, (2) rebar density, (3) epoxy coating on the rebar, (4)...
Substations are a crucial element at the transmission and distribution level of electric power systems. The primary substation equipment (power transformers and high voltage switching equipment) is used to transfer and transform electric energy by stepping up or down the voltage in transmission substations. Secondary equipment (such as IEDs, Intelligent...
Performing bridge inspections can be a very daunting task for every department of transportation (DOT) in the country. Because the leading cause of deterioration in reinforced concrete bridge decks is corrosion of the steel reinforcement, the ability to detect the concentration of corrosion-causing chlorides in the concrete, using a non-destructive...
Scalable array transceivers with wide frequency tuning range are attractive for next-generationradios. Key challenges for such radios include generation of LO signals with widefrequency tuning range, scalable synchronization between multiple array unit cells andtolerance to in-band and out-of-band interferers. This thesis presents approaches toaddress these challenges in commercial CMOS technologies.The...
The sexually transmitted disease gonorrhea, caused by the Gram-negative bacterium and obligate human pathogen Neisseria gonorrhoeae, remains a significant health and economic burden worldwide. In the absence of a protective vaccine, antimicrobial agents are the only pharmacological intervention for patients with gonorrhea. However, due to the remarkable ability of gonococcus...
This thesis presents a channelized digital receiver design for UWB sytems in a multipath indoor environment. The UWB technology has been used for commercial and military purposes due to a number of advantages such as low-power consumption, noise-like and carrier free. The energy of UWB signal is spread over a...
Multi-level decision feedback equalization (MDFE) is a sampled signal processing technique for data recovery from magnetic recording channels which use the 2/3(1,7) run length limited code. The key adaptive feedback loops in MDFE are those which perform the timing recovery, gain recovery, dc offset detection, and adaptive equalization of the...
High-pressure torsion (HPT) is used to investigate the formation of a new metal system by the direct bonding of separate disks of Al and Cu by processing at room temperature under a compressive pressure of 6.0 GPa and with increasing numbers of HPT turns up to 60. A detailed examination...
The first goal of this master’s thesis was to investigate the linkage between a non-destructive testing method, surface resistivity, and premature concrete deterioration brought on by chloride ingress and or freeze-thaw cycling. The experimental method for this project consists of taking surface resistivity measurements of reinforced concrete slabs after they...
The miniaturization of Microtechnology-based Energy, Chemical and Biological Systems (MECS) is made possible by the use of high aspect ratio microchannel arrays to increase the surface-area-to-volume ratio of the flow conduits within the devices, resulting in an improvement in the heat and mass transfer performance of the devices. However, advantages...
Powerline communication (PLC), is becoming a more commonplace method for data transmission, however it is still a very new medium for data transmission, and international standards for powerline communication are still in the process of being developed and established. PLC can provide a means of simplifying the device connectivity to...
Flavored milk is a growing category for dairy products; however, it is a perishable product that is subject to microbial spoilage which can lead to a negative consumer experience and lead to lost sales. Flavored milk processors communicated unique spoilage events related to their products, including color loss of strawberry...
The intriguing size- and shape dependent properties of nanoparticles have garnered recent attention in many science and engineering areas. When the particle size is in the nanometer size range, the material exhibits very different properties such as surface plasmon resonance (of gold nanoparticles) and superparamagnetism (of iron oxide nanoparticles). The...
Selecting an appropriate and efficient sampling strategy in biological surveys is a major concern in ecological research, particularly when the population abundance and individual traits of the sampled population are highly structured over space. Multi-stage sampling designs typically present sampling sites as primary units. However, to collect trait data, such...
This dissertation investigates the use of a hardware mechanism called Eager Data Transfer (EDT) for achieving the reduction of communication latency for user-level network protocol. To reach the goal, the dissertation addresses the following research issues. First, the development of a communication system performance evaluation tool called Linux/SimOS is presented....
High data rate transmission has become an important challenge in today digital communication systems. One of the most difficult problems faced by engineers is to transmit data at sufficiently high rates through fading channels. This is the main motivation for the research presented herein. In this thesis, we investigate a...
The quest to achieve reliable communication has always existed. Error Correcting codes have made communication systems even more reliable under high signal to noise ratios. A new class of codes called Turbo codes have proved to be more effective compared to the other classes of codes and achieve performance close...
Dental resin composites are widely used in modern dentistry due to their aesthetic appearance. However, resin based restorations have inferior mechanical properties (fracture is the second reason for restorations replacement) in comparison to alloy based composites and their antimicrobial properties still remain poor, leading to secondary tooth decay development on...
A digital implementation of a PLL has several advantages compared to its
analog counterpart. These include easy scalability with process shrink, elimination
of the noise susceptible analog control for a voltage controlled oscillator (VCO) and
the inherent noise immunity of digital circuits. Several recent digital PLL (DPLL)
implementations have achieved...
The deployment of advanced technology standards for 5G and beyond in cellular networks has resulted in interest in integrated circuits (ICs) operating at frequencies above 10GHz. This has sparked research on wideband circuits in commercial low-cost silicon technologies, operating at high RF and mm-wave frequencies. Given the wide range of...
Growing concerns over the rise of anthelmintic resistant populations of gastrointestinal nematodes (GINs) have led producers to look for alternative means of treatment. These sentiments have been echoed by organic producers, who are restricted from the use of synthetically derived anthelmintics in the US. Chicory has emerged as a potential...
Measuring resistivity as a method to calculate formation factor is becoming a popular way to evaluate transport properties of concrete. Resistivity measurements are dependent on multiple factors including the resistivity of the pore solution, leaching effects, the degree of saturation of the specimen, the age of the specimen (degree of...
Large databases and data warehouses are becoming prevalent for the storage and management of energy data. Accelerating the rates at which data can be retrieved is beneficial not only to allow for more efficient search of the data, but also to be integrated with other energy system tools. In this...
Direct-conversion architecture would dominate the modern low power wireless receiver architecture if problems such as offset cancellation, even-order distortion, and flicker noise were solved. Among those problems, offset is the most serious one. This thesis will discuss and analyze one approach to cancel offsets in direct-conversion receivers. First, we explain...
A variety of important machine learning applications require predictions on test data with different characteristics than the data on which a model was trained and validated. In particular, test data may have a different relative frequency of positives and negatives (i.e., class distribution) and/or different mislabeling costs of false positive...
Ultra-wideband (UWB) radio is the transmission of data using an extremely wide bandwidth and very low power spectral density. In this thesis, the mereits and challenges of UWB architectures versus conventional narrowband architectures will be compared. Pulsed UWB systems can be implemented with very simple architectures. These advantages make UWB...
The purpose of this study is to investigate the performance and stability of
the gas-injection enhanced natural circulation in heavy-liquid-metal-cooled systems.
The target system is STAR-LM, which is a 400-MWt-class advanced lead-cooled
fast reactor under development by Argonne National Laboratory and Oregon State
University. The primary loop of STAR-LM relies...
Despite the dissemination of comprehensive reviews and teacher-friendly resources describing evidence-based practices to improve student outcomes, the adoption of these practices is slow and inconsistent across instructors at colleges and universities. To help reduce this research-practice gap, I argue for the application of implementation science to teaching and learning research...
Two experiments evaluated nutritional management of late-gestating beef cows to enhance offspring productivity. The objective of experiment 1 was to evaluate the effects of organic and inorganic Cu, Mn, Zn, and Co supplementation to beef cows during late-gestation on performance and physiological responses of the offspring. The objective of experiment...
Significance: Parasite survival and virulence relies on effective defenses against reactive oxygen and nitrogen species produced by the host immune system. Peroxiredoxins (Prxs) are ubiquitous enzymes now thought to be central to such defenses and, as such, have potential value as drug targets and vaccine antigens. Recent Advances: Plasmodial and...
Over 100 years separate the 1918 Influenza and COVID-19 pandemics, and a multitude of science, public health and communication advancements have emerged. With the COVID-19 pandemic still underway, recently reaching the one million death mark in the United States alone (CDC, 2020), researchers are searching for clues as to how...
Since the dawn of the computer age, there has been a push to create miniature
devices. These devices were initially integrated circuit (IC) devices to perform
calculations for computers. As the technology progressed, the scope of the devices
diverged to included microelectromechanical (MEMS) devices, meaning that the devices
perform mechanical...
Oregon strawberries are known for their high quality, intense flavor, sweetness, and rich red color. With optimal weather conditions, including rainy and mild seasons, Oregon has one of the best strawberry farming environments. Amongst the factors for a suitable strawberry farming environment, soil significantly influences strawberry growth and quality. The...
Cognitive radio technology emerges as a promising solution for overcoming shortage and inefficient use of spectrum resources. In cognitive radio networks, secondary users, which are users equipped with cognitive radios, can opportunistically access spectrum assigned to primary users, the spectrum license holders. Although it improves spectrum utilization efficiency, this opportunistic...
Oregon State University has hosted an International Atomic Energy Agency (IAEA) International Collaborative Standard Problem (ICSP) through testing conducted on the Multi-Application Small Light Water (MASLWR) facility. The MASLWR facility features a full-time natural circulation loop in the primary vessel and a unique pressure suppression device for accident scenarios. Automatic...
In networked control systems (NCS) information or packets usually flow from a
sensor or a set of sensors to a remotely located controller. Then the controller
processes the received information and sends a series of control commands to the
actuators through a communication network which could be either wireless or...
This study investigates how teachers develop and extend their understanding and knowledge of teaching and learning with digital technologies in a primarily online Master of Science program. The investigation focuses on exploring the relationship between developing an online community of learners and the construction of technological pedagogical and content knowledge...
Natural disasters are an increasingly costly and frequent occurrence globally and in the United States (IPCC, 2012; IPCC, 2014; Berlemann & Steinhardt, 2017). Discrete disaster events, such as coastal flooding, have been shown to be push factors in temporary and long-term migration (Black et al., 2013). Policy efforts to adapt...
Exercise programs that are individualized and moderately challenge balance to address falls risk factors are recommended for preventing falls in community-dwelling older adults. Little is known regarding the biomechanical and postural control demands in exercises commonly performed in falls prevention programs. Twenty-two non-sedentary, healthy older adults (11 men, 11 women,...
Control rod calibration experiment results for the Oregon State TRIGA® Reactor (OSTR) immediately following LEU conversion in 2008, and MCNP® 5 predicted rod worths from the 2008 LEU Conversion Safety Analysis Report (CSAR) are discussed. The reactivity worth of the four OSTR control rods are measured using the rod-pull method....
Interest in performance specifications has been growing in the civil and construction industry in the past decade. One major focus area has been on understanding how to prolong the service life of concrete structures, since repair and rehabilitation of existing infrastructure have cost many trillions of dollars. Deterioration mechanisms such...
Power can be defined as the ability to influence the processes, decisions, and outcomes of an activity in favor of the will of a strong actor and its allies. Strategic actions in situations where there is asymmetric power can change the result of decisions. In this research, I will examine...
Electrochemical capacitors and batteries are two major electrochemical energy storage technologies, which have been investigated extensively to meet the rapidly-growing demand for higher energy, higher power, lower cost and enhanced safety in the past few decades. With the charge storage mechanism of electrostatic charge adsorption desorption via electrical double layers,...
Particle-laden turbulent flows, wherein a large number of small size particles are dispersed in a fluid, are widely encountered in environmental and industrial applications. Understanding their underlying physics, making predictions without performing expensive experiments, and ultimately optimizing the systems carrying such flows, require accurate and robust modelling tools. The Euler-Lagrange...
Scientists and engineers have to analyze and query multiple large databases. Analysis over databases created by phasor measurement units can provide insight into the health of the grid, thereby improving control over operations. Realizing this data-driven control, however, requires validating, processing and storing massive amounts of PMU data efficiently, which...
Global warming is becoming an increasingly important environmental concern and CO₂ is considered as the major cause of global warming. Creating useful applications for CO₂ would generate alternatives to merely venting CO₂ to the atmosphere, and decreasing the carbon intensity of human activities. Among various methods of CO₂ utilization, conversion...
Microplastics (MPs) are plastic particles less than 5 mm in diameter. These contaminants are increasingly found in the environment due to increased plastic production, use, and improper disposal. Detecting and measuring these contaminants in the environment has proven difficult, requiring the use of fate and transport models to assess MP...
It has been estimated that data traffic from the different mobile devices that range from smartphones to machine-to-machine (M2M) devices will exceed 15.9 exabyte per month by the year 2018. With this immense data growth, the current wireless communication systems suffer from the scarcity of the radio spectrum and eventually...
Building software systems that adapt to the changing environment is challenging. Developers cannot anticipate all the changes in advance, and even if they could, the effort required to handle such situations is too onerous for practical purposes. Self Adaptive Software (SAS) adapts itself as per changing environment. The area of...
Organic compounds which contain one or more nitrogen atoms are especially important as they are disproportionately represented among biologically active molecules. As a result, significant effort has been focused on the development of methods for the synthesis of nitrogenous molecules. We identified the aminal as an under-explored functional group. Despite...
The focus of this thesis is to design, characterize, and apply novel computational methods and molecular systems to interrogate heterogeneous human gut microbiome-related phenomena. In Chapter 2, I design, implement, and characterize a method for embedding co-occurrence patterns derived from massive 16s amplicon datasets. I use this method to 1....