With the increase in demand for streaming media capabilities across the Internet, the focus has shifted from traditional client-server to peer-to-peer approaches. Content Distribution Networks (CDNs) have also recently moved from web acceleration to media streaming. P2P CDNs can be used both as a delivery mechanism and as an independent...
The goal of the Pacific Ocean Boundary Ecosystem and Climate Study
(POBEX) was to diagnose the large-scale climate controls on regional transport
dynamics and lower trophic marine ecosystem variability in Pacific Ocean boundary
systems. An international team of collaborators shared observational and eddy-resolving
modeling data sets collected in the Northeast...
Understanding the causal links between riparian forests, streams, and salmonids is important to help understand the likely effects of forest management practices. Previous studies have identified three major causal pathways (Instream Cover, Light, and Hydrology) through which riparian forests influence streams, and ultimately stream fishes. To evaluate the potential importance...
Previous research has shown that using fine lightweight aggregate (FLWA) can be a promising strategy to mitigate alkali-silica reaction (ASR) in mortar and concrete. While several possible theories were proposed by researchers, discrepancies in testing methods, materials, and supporting evidence still exist. Therefore, this study was initiated. There are two...
Alkali-silica reaction (ASR) is one of the leading causes of concrete deterioration throughout the world, and affects both structural and non-structural elements. Despite strong research efforts since its discovery by Stanton in the late 1930s, this deteriorating reaction is still not clearly understood nor are proper preventative measures effectively applied...
According to most health organizations, "obesity" (defined as body mass index [BMI] greater than 30) is a world health problem of "epidemic" proportions. The underlying assumption is that weight is a proxy for health. However, obesity prevention and reduction interventions are designed to regulate body weight, rather than improve health....
Ecological resources available to freshwater fish shift spatially, temporally and across life stages. To better understand how spatial-temporal availability of resources influence fish, I examined the phenologies of hatching and emergence of Coho Salmon (Oncorhynchus kisutch) in streams with contrasting and strongly defined seasonal thermal variability. The study streams included...
PURPOSE: We tested the hypothesis that the unsupervised, isokinetic 3- minute all-out cycling test (3MT) would be a valid and reliable way to determine end power (EP) and work done above end power (WEP). Additionally, we hypothesized that EP would successfully demarcate between heavy and severe-intensity exercise and thus represent...
The use of fly ash as a supplementary cementitious material (SCM) has increased in the last century due to its various environmental benefits as a recycled product. Within the last 60 years, it has been found that it can be used to effectively control damage induced by Alkali-Silica Reaction. However,...
Internal curing is a term used to describe a process in which curing water is provided to a concrete mixture from inside the mixture. Internal curing water has typically been provided in North America mixtures by using prewetted porous materials, like fine lightweight aggregate (FLWA). Alternative materials, such as superabsorbent...
Alternative male phenotypes in salmonine fishes arise from individuals that mature as either larger and older anadromous marine-migrants or as smaller and younger freshwater residents. Variability in age and size of males at maturity is hypothesized to be preceded by early differences in growth in size and lipid storage. Water...
High Performance Concrete (HPC) is used in our crucial pieces of infrastructure, such as bridge decks, due to its enhanced durability and engineering properties. However, HPC is highly susceptible to early-age cracking. Cracking within the first months of a bridge deck’s lifespan can severely hinder its long-term performance and durability....
Tightness-looseness (TL) is a cultural construct that measures the level of social norms present in a community, and the level of scrutiny of deviance from these norms. This construct offers a unique foundation for investigating how norms influence behavioral processes. Research in TL is relatively young, creating a frontier of...
Objectively quantifying workload is challenging due to a variety of factors. One way to measure workload is by training impulse (TRIMP). TRIMP uses time in physiologically significant heart rate zones to quantify a workload for a given bout of physical activity. Tracking average workload over time can then be used...
Studies of the effects of forest harvest on streams and fish have a long history in the Pacific Northwest. Results of this work have prompted development of new forest harvest practices that are more protective of these resources, but the effectiveness of these new practices has not been fully evaluated....
:
_____________________________________________________________________
Jason B. Dunham
Studies of the effects of forest harvest on streams and fish have a long
Coastal cutthroat trout (Oncorhynchus clarkii clarkii) and cottids (Cottus spp) commonly co-occur in headwater streams in western Oregon. Little is known about the comparative trophic ecology of these species or how they respond to seasonal scarcity of resources. In this study I evaluated the seasonal variability in diets and consumption...
Large wood has been utilized in many restoration projects to improve in-stream habitat in the Pacific Northwest for salmon. However, the benefits of this practice remain the subject of ongoing debate and evaluation of these projects has scarcely been done for non-salmonid species such as lamprey. In this study we...
:
________________________________________________________________________
Jason B. Dunham
Large wood has been utilized in many restoration projects to improve in
In the field of civil infrastructure, bridge desks are typically constructed using high performance concrete (HPC). Concrete bridge decks demand qualities such as low permeability, high abrasion resistance, superior durability, and long design life. Over decades of field and laboratory experience, many HPC bridge decks have been found to be...
The purpose of this thesis is to examine and compare sustainable design methods used in the United States and Chile, focusing on sustainable materials and certification programs, to see if sustainable design methods used in the United States can be implemented in Chile to further its sustainable development. Through literature...
The Critical Power - W’ model has many advantages compared to the traditional VO2max test, including tracking fitness changes over time in well trained athletes, predicting performances due to its discrete aerobic and high intensity tolerance variables, and prescribing exercise intensities with increased accuracy. However, a major disadvantage of this...
Sonification, or the “technique of rendering sound in response to data and interactions” [1], is an alternative to visual graphs and has the potential to make data more interpretable and accessible. As a combination of the arts (music) and the sciences (data), sonification is an interdisciplinary tool for connecting people...
High early strength (HES) concrete is becoming increasingly used to repair damaged concrete pavement sections. The use of HES concrete enables the repaired pavement to be opened to traffic within hours of placing the concrete. A common approach used for the rapid repair of concrete pavement consists of closing a...
Mean-squared errors of surface geostrophic velocity estimates from the crossover and parallel-track methods are calculated for altimeters in the Ocean Topography Experiment (TOPEX)/Poseidon and Jason orbits. As part of the crossover method analysis, the filtering properties and errors of cross-track speed estimates are examined. Velocity estimates from both the crossover...
Successful prediction of nearshore sediment migration is important in determining the vulnerability of a coastline. During energetic wave climates (storm events) sediment rapidly erodes from beaches and is deposited offshore. In subsequent milder wave conditions, the sediment migrates shoreward, accreting on the beach and helping to protect the coastline. It...
This dissertation provides a comparison of statistical and econometric frameworks, using a previously unused freight data source, to study crash frequency by crash type and heavy-vehicle hard braking in Oregon. Hard braking can serve as a proxy for several factors, one of which is safety. Therefore, with the hard braking...
The Cascadia Subduction Zone has recently been identified as a source for an impending great earthquake. The potential of a large earthquake has created widespread interest into the resiliency of lifelines within the potentially affected areas. One critical lifeline is the electrical distribution and transmission systems which relies on legacy...
Using recycled concrete aggregate (RCA) as a replacement for natural aggregate in new concrete is a promising way to increase the overall sustainability of new concrete. This has been hindered, however, by a general perception that RCA is a sub-standard material due to the lack of technical guidance, specifically related...
In the past ten years, renewed research interest has shown the benefits of internal curing by incorporating saturated lightweight fine aggregate (LWFA) in high performance concrete (HPC). As a result, the technology of internal curing has steadily progressed from laboratory studies to field applications. To determine the optimum LWFA content,...
In this study, we used a combination of conventional statistical analyses and mechanistic bioenergetics models to understand the potential effects of environmental variability on growth of stream-living fishes in four headwater streams subject to upstream forest harvest. We focused on two common fish consumers in headwater streams in the Pacific...
As human-robot interaction becomes more commonplace, roboticists should understand how robot behaviors are perceived by people to avoid misunderstandings. In our lab, we are exploring the use of a Cozmo as an interactive, break-taking aid in workplace settings. Before our interactive aid can be released into the wild, we must...
There is renewed interest in North America for the use of calcium aluminate cement (CAC) in infrastructure repair. The interest is driven by the specialty properties that make CAC the ideal candidate for particular applications. These include rapid strength gain, even at temperatures approaching 0°C, the ability to customize fresh...
Subduction zone earthquake and tsunami hazards affect tens of millions worldwide and the recurrence of these disasters can be evaluated with paleoseismic techniques, because earthquake cycles (and their supercycles) typically span many millennia. In these three chapters, I discuss a suite of analyses I use to evaluate the sedimentary record...
Chloride-induced corrosion is one of the primary causes of the degradation of reinforced steel in concrete structures. Currently, the rapid chloride permeability test (RCPT) is the most specified method to determine the concrete’s resistivity to chloride ingress, thus a determining factor in assessing the durability of concrete. While it is...
Maximal aerobic capacity (V̇O₂max) is the most widely used measure for assessing cardiorespiratory fitness. It is a strong contributor to performance in endurance sports, predicts functional capacity in older adults, and is related to overall disease risk. As such, it is important that testing methodologies for determining V̇O₂max provide valid...
High early strength concrete (HESC) allows for faster construction with less impact on traffic, thus reducing the indirect costs associated with a project. There are multiple methods for achieving early strength, such as alternative cements like calcium sulfoaluminate (CSA) or chemically accelerated portland cements. The standard criteria for an HESC...
The goal of the first part of this project was to investigate the influence of aggregate source and entrained air on the transport properties of concrete. Currently, there are several ASTM standards available that provide systematic procedures to evaluate mass transport properties of concrete. ASTM C642-13 (ASTM 2013), often referred...
Shallow lakes exist in either a clear or turbid state, with the clear state characterized by an abundance of aquatic macrophytes, diverse aquatic biota, low water column nutrients and phytoplankton biomass, whereas the turbid state is characterized by the opposite. These two distinct states are maintained by reinforcing (positive) feedback...
During applied signal-detection (e.g., airport-baggage screening) human operators can be assisted in their decision-making process by automated devices. Automation implementation is aimed at increasing performance relative to unaided levels. Generally, this intended effect is empirically observed. However, operators consistently fall short of optimal levels of aided performance, indicating suboptimal aid-use...
I evaluated hypotheses related to growth as a driver of depth use and diel vertical migration by bull trout (Salvelinus confluentus) in a thermally stratified reservoir. I applied a bioenergetic model to evaluate growth of bull trout in relation to potential patterns of diel depth use by bull trout in...
:
_____________________________________________________________________
Jason B. Dunham
I evaluated hypotheses related to growth as a driver of depth use and diel
Deep mixing events in the ocean’s surface layer act as physical drivers of carbon export by detraining dissolved and particulate organic matter, including surface phytoplankton communities, to depth. Once removed from the sunlit surface ocean environment, phytoplankton accumulation rates are dependent on the relative contributions of loss processes, such as...
The most common test methods to evaluate alkali-silica reaction (ASR), the concrete prism test (CPT) and the accelerated mortar bar tests (AMBT), have limitations and are not entirely reliable in terms of predicting the performance of concrete with prevention measures under field conditions. In this study, the miniature concrete prism...
In the Pacific Northwest ecoregion of North America, sculpins represent a major constituent of freshwater assemblages in coastal rivers. Based on their prevalence and abundance, sculpins are likely important ecologically, yet little is known of their interactions with co-occurring species, such as widely studied salmon and trout (salmonines). In this...
High performance concrete (HPC) provides a long lasting, durable concrete that is typically used in bridge decks due to its low permeability, high abrasion resistance, freeze-thaw resistance and strength. However, this type of concrete is highly susceptible to the deleterious effects of both autogenous and drying shrinkage. Both types of...
Automated decision aids can improve human decision-making but the benefits are often compromised by inefficient use. The current experiment examined whether metacognition—the ability to assess self-performance—and numeracy—the ability to understand and work with numbers—predict the efficiency of automation use in a signal detection task. Two-hundred twenty-one participants classified random dot...
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...
Riparian forests provide a myriad of ecosystem functions for adjacent streams and rivers, and due to these linkages, changes in riparian forest conditions can have direct implications for stream ecosystems. Resource managers in the coast redwood forests (Sequoia sempervirens) of northern California (USA) are actively thinning second-growth stands to accelerate...
Due to its availability, versatility, structural capability, and economic advantages, concrete is the most widely used material in building sewer networks and other wastewater structures such as treatment stations, wastewater digesters, septic tanks, pumping stations, hydraulic risers, utility risers and covers, etc. Concrete structures exposed to sewer environments can experience...
The purpose of this study was to examine the validity and reliability of the 30-minute cycling time trial to estimate the heart rate at lactate threshold. Recreationally trained cyclists and triathletes (n = 47) performed 3 tests in random order: 1) One graded exercise test to directly determine lactate threshold...
:
_________________________________________________________________________________________________________
Jason
T.
Penry
The
purpose
of
this
study
was
to
examine