Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Paleomagnetism (13)
- Geology (12)
- Climate change (8)
- Net shore-drift (8)
- Petrology (8)
-
- Stratigraphy (7)
- Hemophilia A (6)
- Sortase (6)
- Chuckanut Formation (5)
- Climate Change (5)
- Hydrology (5)
- Mars (5)
- Mount Baker (5)
- Restoration (5)
- Blood Coagulation Factor VIII (FVIII) (4)
- Geochronology (4)
- Glacier (4)
- Salish Sea (4)
- Sediment transport (4)
- Sedimentology (4)
- Spectroscopy (4)
- Structure (4)
- X-ray Crystallography (4)
- Benzoxazine (3)
- Biochemistry (3)
- Climate (3)
- Ecosystem (3)
- Eelgrass (3)
- Enzyme (3)
- Flooding (3)
- Publication Year
Articles 1 - 30 of 552
Full-Text Articles in Physical Sciences and Mathematics
Deglacial And Holocene Environmental Change Recorded In Lake Sediments From The Snowy Mountains, Kosciuszko National Park, Southeastern Australia, Emma J. Mickelson
Deglacial And Holocene Environmental Change Recorded In Lake Sediments From The Snowy Mountains, Kosciuszko National Park, Southeastern Australia, Emma J. Mickelson
WWU Graduate School Collection
The sediment record from Lake Albina, the Snowy Mountains, southeastern Australia suggests significant environmental change mostly reflecting shifts in climate from the LGM through the Holocene. Immediately following deglaciation, approximately 19.4 thousand cal ky BP, Lake Albina experienced cold and/or dry conditions with minimal vegetation in the catchment. Cooler conditions persisted with a slight increase in moisture throughout the Antarctic Cold Reversal (ACR; 14.7-13 cal ky BP) aligning closest with a strengthening of the Atlantic Meridional overturning circulation (AMOC) and a northward shift of the South Westerly Winds (SWW). Between 12.9-9.7 cal ky BP, Lake Albina recorded a climate reversal …
Distribution And Mixotrophy Of Cryptophyte Phytoplankton In The Northern Gulf Of Alaska, Megan O'Hara
Distribution And Mixotrophy Of Cryptophyte Phytoplankton In The Northern Gulf Of Alaska, Megan O'Hara
WWU Graduate School Collection
The Northern Gulf of Alaska (NGA) is a productive subarctic marine ecosystem that supports high abundances of plankton, fishes, seabirds, and mammals. Research has shown that this high productivity is primarily controlled by seasonal and spatial heterogeneity in the lower trophic level food web. Marine cryptophytes are a crucial, yet understudied, phytoplankton group in the NGA. Cryptophytes have the capacity for mixotrophy (acquiring energy through photosynthesis and feeding) which can improve trophic transfer efficiency, increase cellular growth rates, and improve retention of nutrients in the water column. Field samples collected in spring, summer, and fall 2021 surveyed the contribution of …
The Economic And Emissions Reduction Potential Of Air Source Heat Pumps As A Replacement For Natural Gas And Electric Resistance Space Heating In The Contiguous United States, Joshua Schraer
WWU Graduate School Collection
It is widely believed that to reduce CO2 emissions the best strategy is to electrify everything, decarbonize the grid, and improve energy efficiency. This research looks specifically at the use of air source heat pumps (AHP) as a tool to reduce the CO2 emissions of heating energy in the residential sector. The landscape of residential energy use is complicated by a broad range of factors. We compare AHP, natural gas (NG), and electric resistance (ER) heating using data from energy prices, temperature, appliance efficiency, building efficiency and marginal emissions data from 2019 as well as modeled data of …
Impact Of Carbonaceous And Inorganic Nanomaterial Chemistry On Polymer Additive Release From Weathered Epoxy Composites, Haley Sefi-Cyr
Impact Of Carbonaceous And Inorganic Nanomaterial Chemistry On Polymer Additive Release From Weathered Epoxy Composites, Haley Sefi-Cyr
WWU Graduate School Collection
Nanomaterials (NMs) are small (< 100 nm), reactive, chemical species that can often be used as polymer fillers to improve mechanical strength and slow the degradation of polymer nanocomposites (PNCs). Polymers can undergo physical and chemical weathering which can result in increased release of polymer additives and non-polymerized monomers from the polymer matrix. This project aimed to study how NM chemistry and environmental weathering impacts the release and transformation of relevant PNC systems. Bisphenol A diglycidyl ether (BADGE) PNCs were synthesized containing titanium dioxide (TiO2), multi-walled carbon nanotubes (MWCNT), or graphene oxide (GO) NMs. These composites were subjected to either simulated or natural weathering conditions to quantify and characterize their capacity to leach endocrine-disrupting chemicals. Environmental variables, including temperature and ultra-violet (UV) light, were investigated for their impact on additive release. Fourier-transform infrared spectroscopy and Raman microscopy were used to characterize the PNCs which were leached in water for one to five days at 25, 45, or 65 °C. The degree of weathering also varied from no weathering, outdoor weathering, or simulated weathering using UV light. Leachates were analyzed using high-performance liquid chromatography quadrupole time-of-flight mass spectrometry to quantify release of bisphenol A (BPA), tert-butylphenol (TBP), and nonylphenol (NP). There were significant differences between NM types for PNCs weathered outdoors and leached at 25 °C for 24 h, however only TBP was detected in the leachate. When compared to the blank epoxy, GO PNCs leached significantly less in the UV and in May outdoor weathered experiments, MWCNT PNCs leached significantly less when weathered outdoors in May and June, and TiO2 PNCs leached significantly less when UV weathered. Each of the NMs has potential to decrease TBP release through sorption or photodegradation. The carbonaceous NMs (GO and MWCNT) may sorb TBP, inhibiting its release, while TiO2 may photodegrade TBP. The unweathered PNCs leached the most TBP, followed by UV weathered, and then outdoor weathered. A possible explanation for this is photodegradation of TBP by UV light in the UV- and outdoor-weathered experiments leading to removal of TBP prior to leaching. Future experiments should include additional sorption trials and long-term natural weathering with microplastic generation to further explore the release and degradation mechanisms.
Modeling 21st Century Peak Flows In The Nooksack River Basin In Northwestern Washington State Using Dynamically-Downscaled Global Climate Model Projections, Evan A. Paul
WWU Graduate School Collection
The Nooksack River in northwestern Washington State provides freshwater for agriculture, municipal, and industrial use and serves as a vital habitat for endangered salmon, a resource that is of cultural and economic importance to the Nooksack Indian Tribe and the surrounding region. As more landscape becomes exposed to rain rather than snow and heavy winter precipitation events intensify (i.e., atmospheric rivers), peak flows and sediment delivery to streams will increase due to rapid runoff, resulting in salmon habitat degradation and increased flood risk. Thus, anticipating the effect of climate change on peak flows is crucial for salmon habitat restoration efforts …
Impact Of Riverbank Lupine (Lupinus Rivularis) On Grand Fir (Abies Grandis) Ectomycorrhizal Symbioses, Andrew Labay
Impact Of Riverbank Lupine (Lupinus Rivularis) On Grand Fir (Abies Grandis) Ectomycorrhizal Symbioses, Andrew Labay
WWU Graduate School Collection
Lupine (Lupinus rivularis) is used in the revegetation of coarse sediments surrounding the Elwha basin in Washington State due to its ability to improve soil conditions. Previous research illustrated that seeding lupine with conifers increased growth and foliar nitrogen, however, decreased ectomycorrhizal (ECM) root colonization, an important symbiosis for conifers used in restoration. We hypothesized the observed decrease in ECM may be due to lupine increasing soil nitrogen, negating the need for a fungal symbiont. To investigate this, we explored the interaction between lupine and ECM colonization of grand fir (Abies grandis) in both a field …
Activity And Selectivity Of Class B Sortase Enzymes, Sophie Jackson
Activity And Selectivity Of Class B Sortase Enzymes, Sophie Jackson
WWU Graduate School Collection
Gram-positive bacteria attach many proteins to their cell walls via sortase enzymes. Sortases are cysteine transpeptidases and are grouped into 6 classes, A-F. Sortase enzymes, particularly sortase A from Staphylococcus aureus, have been used extensively for in vitro protein ligations. Here, we investigate substrate-binding in sortase A from Streptococcus pyogenes. In addition, class B sortases are typically overlooked for research and development due to low in vitro activity and incomplete knowledge of substrate specificity. Here, we investigate the activity of class B sortases from Bacillus anthracis (baSrtB), Clostridioides difficile (cdSrtB), Listeria monocytogenes (lmSrtB), and Staphylococcus aureus (saSrtB). Of these, …
Glacial Loss And Threatened Fish: The Future Of Mount Rainier’S Cold-Water Bull Trout Habitats, Kathleen C. Ewen
Glacial Loss And Threatened Fish: The Future Of Mount Rainier’S Cold-Water Bull Trout Habitats, Kathleen C. Ewen
WWU Graduate School Collection
Glaciers play a key ecological role in the river systems that they support. Cold-water reaches supplied by glacial ice serve as critical habitats for aquatic organisms that rely on specific thermal ranges to survive. Federally threatened Bull Trout (Salvelinus confluentus) require very cold temperatures, like those found in glacial systems, to complete their life cycles. However, glaciers are retreating due to climate change and are expected to continue diminishing throughout this century. Decreased glacial extent could result in warmer stream temperatures downstream from glaciers and, depending on the magnitude of stream temperature increase, cold-water habitats relied upon by Bull Trout …
Stereoselective Synthesis Of (+)- And (-)-Cananodine, Haley Holliday
Stereoselective Synthesis Of (+)- And (-)-Cananodine, Haley Holliday
WWU Graduate School Collection
Natural products are an important class of molecules utilized in traditional medicine and inspire drug design in medicinal chemistry. Cananga odorata, a tree commonly known as ylang-ylang, contains natural products known to positively benefit health, and specifically promote liver health. One alkaloid isolated from Cananga odorata, cananodine, possesses cytotoxic properties, specifically against hepatocellular carcinoma (HCC). HCC is the most common type of liver cancer, with one million diagnoses projected by 2025 globally. Cananodine is a member of the guaipyridine alkaloid family, a class of compounds that feature a substituted pyridine bonded to a seven-membered ring. The first enantiomer …
Selectivity And Structure Of Chimeric Loop Swaps In Sh2 Domains, Sarah N. Smith
Selectivity And Structure Of Chimeric Loop Swaps In Sh2 Domains, Sarah N. Smith
WWU Graduate School Collection
SH2 (Src Homology 2) domains are protein domains that bind to phosphorylated tyrosine residues within cell signaling cascades. They have been found to play a role in certain cancers and immunological disorders. Despite their importance in cell signaling and medical relevance, the structural basis of the various selectivity classes of SH2 domains is only partially understood. Previous research found that the EF and BG loops of the domains contribute to forming the peptide binding pocket, and thus impact their selectivity. To further understand the role of these loops in selectivity, we engineered chimeric SH2 domains by swapping the EF and …
Tuned Gold Layer Growth Onto Plasmonic Sensing Silver Nanocubes Via Synthetic Control Of Reduction Potentials., Nicolas Hall
Tuned Gold Layer Growth Onto Plasmonic Sensing Silver Nanocubes Via Synthetic Control Of Reduction Potentials., Nicolas Hall
WWU Graduate School Collection
Metallic nanoparticles (mNPs) are commonly employed as sensors and detection tools due to their unique plasmonic properties. Silver NPs exhibit these properties in heightened capacity in comparison to other metals. However, Ag NPs are susceptible to oxidation, degradation over time and are biotoxic. These issues are commonly addressed by creating Ag-alloy NPs or by adding additional layers to Ag NPs. This work improves upon these methods by focusing on the growth of an Au layer onto Ag nanocubes (AgNCs), resulting in a layered Au-Ag NC (Au@AgNC). The resulting morphology of these Au@AgNCs are dependent on the synthetic pathway taken and …
Connections Between Eruption Style And Magmatic Reservoir Evolution: Insights From Augustine Volcano, Alaska, Usa, Mahinaokalani G. Robbins
Connections Between Eruption Style And Magmatic Reservoir Evolution: Insights From Augustine Volcano, Alaska, Usa, Mahinaokalani G. Robbins
WWU Graduate School Collection
At a single volcano, eruptive behavior can change through time as the plumbing system evolves. Augustine Volcano, a frequently active intermediate stratovolcano in the Alaska-Aleutian arc (USA), is an ideal setting to investigate magma reservoir processes due to its frequent modern and Holocene eruption history. Its most recent 2006 CE eruption included mixed effusive and moderately explosive (VEI 3) events and has been studied in detail. Proximal fall deposits from this eruption were generally mixed fine ash to lapilli with variable thickness, but typically ~5 cm on the island (Wallace et al., 2010). The Pre-contact “Tephra M” was deposited by …
Trophic Transfer Of Metals From Seaweed To Shellfish In An Aquaculture System, Sophia Boyd
Trophic Transfer Of Metals From Seaweed To Shellfish In An Aquaculture System, Sophia Boyd
WWU Graduate School Collection
Seafood, including fish, shellfish, and seaweed, are an important source of nutrients that could meet some of the increasing demand for food globally. In addition to nutrients, chemical contaminants can also be acquired from the environment by primary producers. Seaweeds take up a variety of inorganic and organic contaminants, including metals, that may pose risks to human health. Through trophic transfer, organisms can accumulate elevated levels of contaminants from consuming lower trophic-level organisms. Since particulate organic matter, including seaweed detritus, is a food source for filter-feeding bivalves, contaminants present in seaweed could transfer to shellfish via ingestion. The purpose of …
A Mixed-Methods Study Of Geoscience Identity, Race/Ethnicity, And Gender In Senior Undergraduate Geoscience Majors, Willa Rowan
A Mixed-Methods Study Of Geoscience Identity, Race/Ethnicity, And Gender In Senior Undergraduate Geoscience Majors, Willa Rowan
WWU Graduate School Collection
I conducted a mixed methods study of geoscience identity in undergraduate students to examine the cultural and social aspects of geoscience degree programs. White students are overrepresented in geoscience, and a priority of anti-racism efforts in the field is listening to the experiences of students who are Black, Indigenous, or people of color (BIPOC) to better inform equity and inclusion goals. Structural racism in geoscience pushes BIPOC students out of the field, and it can be better understood by studying socially constructed aspects of learning such as geoscience identity. This study is the first to measure geoscience identity with a …
Using Camera-Monitored Sediment Traps To Evaluate Sediment Availability And The Role Of Waves In Resuspending Seafloor Sediment, Bellingham Bay, Wa, Liam Horner
WWU Graduate School Collection
Understanding nearshore sediment budgets and processes is important for evaluating coastal hazards, habitats, and contaminant fate to enable informed decisions in coastal planning and management. I aimed to evaluate the role of waves in resuspending and redistributing sediments and by proxy contaminants in the urban/estuarine Bellingham Bay, and better understand the transport and rate of fluvial sediment moving through the nearshore. I integrated analyses using camera-mounted sediment traps, seafloor grain-size data, short-lived radioisotopes, and other fluvial, physical oceanographic, and wind data. I paired cameras with sediment traps, to identify the timing and rate of sedimentation on the seafloor at hourly …
Biomarker Study Of Bellingham Bay : Identifying How Urbanization Has Affected Carbon Storage And Eelgrass, Jess Shulman
Biomarker Study Of Bellingham Bay : Identifying How Urbanization Has Affected Carbon Storage And Eelgrass, Jess Shulman
WWU Graduate School Collection
Understanding sediment sources and fluxes throughout coastal zones is essential to evaluate shoreline stability, ecosystem health, and the potential for carbon storage. In Bellingham Bay, WA, like many developed coastal settings, urban areas have replaced forested cover and altered sediment fluxes, yet little is known of their offshore impacts. I analyzed n-alkanes, found in plant leaf waxes preserved in marine sediments of Bellingham Bay to characterize sediment sources and reconstruct changes in the relative contributions of eelgrass beds to sedimentary organic matter since pre-industrial times using a linear mixing model. Eight 2-meter-long cores were analyzed in order to determine how …
Reconstructing Wildfire Regime During The Warm Paleocene-Eocene Climate Using Molecular Biomarkers From The Chuckanut Formation In Northwest Washington, U.S.A., Alexandra Thompson
Reconstructing Wildfire Regime During The Warm Paleocene-Eocene Climate Using Molecular Biomarkers From The Chuckanut Formation In Northwest Washington, U.S.A., Alexandra Thompson
WWU Graduate School Collection
Wildfires are expected to increase in frequency and severity as climate changes in the Pacific Northwest of North America. To better understand the effect of warming climate on wildfire regimes, I present the first reconstruction of past wildfire frequency and severity during the Paleocene-Eocene transition in northwest Washington state, U.S.A. The Chuckanut Formation is a late Paleocene to Eocene sedimentary unit with a robust paleobotanical record showing the existence of subtropical forests in northwest Washington during the Paleocene, transitioning to a relatively cooler Eocene, dominated by temperate mixed forests. Geochemical records of environmental change coinciding with Paleocene-Eocene climatic change in …
Value Mapping And The Community Wildfire Protection Planning Process In Entiat, Wa, Katharine Kiendl
Value Mapping And The Community Wildfire Protection Planning Process In Entiat, Wa, Katharine Kiendl
WWU Graduate School Collection
Community Wildfire Protection Plans (CWPP) offer benefits for communities effected by wildfire risk and ignitions. CWPP’s serve several functions; they develop interlocal agreements between agencies that provide wildfire response and management, they develop hazard mitigation and wildfire education programs, and they define areas as wildland urban interface (WUI). The CWPP drafting process can impact the resources available to a wildfire risk community. However, despite the impact to communities effected by wildfire, CWPP planning is considered a categorical exclusion under the National Environmental Policy Act (NEPA) allowing CWPP’s to be developed without public review. Given that community plans with public participation …
Evaluating Leaf Trait Variation In High Elevation Bristlecone Pine (Pinus Longaeva) Under Increasing Water Stress: Insights From Needle Length, Stomatal Density, And Cambial Growth, Audrey Salerno
WWU Graduate School Collection
Increasing aridification caused by climate change is altering growth patterns in trees. There is revived attention on how foliar traits respond to climate and the relationship of these traits to ring width. Bristlecone pine (Pinus longaeva, DK Bailey), a long-lived conifer found at high elevations in the cool and dry intermountain west of America, is used in paleoclimate reconstructions by measurement of their annually resolvable tree rings. The species also has annually datable needles retained on their branches for an average of 45 years making it the ideal subject for research on foliar trait and growth relationships under …
Contaminants Of Emerging Concern In Puget Sound: Screening, Prioritization, And Estrogenic Mixture Response Assessment, Maya Faber
WWU Graduate School Collection
Contaminants of emerging concern (CECs) are chemicals used in daily life, such as pharmaceuticals, personal hygiene products, steroids, pesticides, and flame retardants. The environmental occurrence and toxicology of CECs are poorly characterized, and they are generally unregulated. Traditional toxicological approaches rely on in vivo methods to test whole organisms for apical endpoints, including survival, reproduction, and growth. This is time-consuming and costly, both financially and in terms of laboratory animal well-being, limiting ecotoxicological data for CECs. To overcome this challenge, we are utilizing alternative approaches, including New Approach Methodologies (NAMs), to perform a screening-level evaluation of CECs present in Puget …
Using Chemical Zoning In Minerals To Understand Magmatic Processes At Augustine Volcano, Alaska, Sloane Kennedy
Using Chemical Zoning In Minerals To Understand Magmatic Processes At Augustine Volcano, Alaska, Sloane Kennedy
WWU Graduate School Collection
The eruption behavior of a volcano is intrinsically linked to magmatic evolution. Augustine Volcano is an active stratovolcano in the Aleutian Arc (AK, USA), showing stratigraphic evidence that eruptions before 1,800 C.E. were more explosive, producing thick pumice deposits, compared to the six eruptions observed in the last 200 years. Tephra B, an understudied ~400-year-old pumice fall unit, represents the last more explosive style eruption at Augustine - making it ideal for studying how changes in magmatic evolution can result in changes in eruption style. For this thesis, I used textural zoning patterns and chemical variations (major and trace elements) …
The Race Toward Carbon Neutral Ecotourism: Leveraging Life Cycle Analysis And Natural Climate Solutions For A Community Adventure Event, Ted Tarricone
The Race Toward Carbon Neutral Ecotourism: Leveraging Life Cycle Analysis And Natural Climate Solutions For A Community Adventure Event, Ted Tarricone
WWU Graduate School Collection
Global tourism is an interconnected framework of multiple industries that is influenced by and has impacts on economic, social, and environmental structures. Currently, tourism accounts for roughly 8% of global greenhouse gas emissions, which is expected to grow with industry expansion. To develop a scalable system for ecotourism assessment, emission reduction, and solutions to meet carbon neutrality, a small (n=3894 participants) adventure relay race named Ski to Sea in Bellingham, WA was studied. A life cycle analysis (LCA) conducted on the race showed similar proportional results to other tourism LCAs, where transport made up over 80% of the 325 tonnes …
U-Pb Zircon Geochronology And Structure Of Regional Blueschist Units In The Easton Metamorphic Suite, Northwest Cascades, Wa, Katherine Lang
U-Pb Zircon Geochronology And Structure Of Regional Blueschist Units In The Easton Metamorphic Suite, Northwest Cascades, Wa, Katherine Lang
WWU Graduate School Collection
The Easton metamorphic suite of the Northwest Cascades Thrust System (NWCS) is a well-preserved subduction accretion complex in Washington State. The regional blueschist units of the Easton metamorphic suite include the Mt. Josephine semi-schist, Darrington Phyllite, and Shuksan greenschist/blueschist and all are interpreted to have accreted after the onset of Jurassic subduction beneath North America. This study uses zircon U-Pb geochronology, structure, and field observations to test the regional correlations between units in the Easton metamorphic suite and address models for the timing of subduction accretion along the North American margin in the Late Jurassic – Early Cretaceous. The results …
Structural And Thermodynamic Studies Of Antibody Binding To Blood Coagulation Factor Viii, Jordan Vaughan
Structural And Thermodynamic Studies Of Antibody Binding To Blood Coagulation Factor Viii, Jordan Vaughan
WWU Graduate School Collection
Blood coagulation factor VIII (FVIII) is a 2332 residue glycoprotein expressed in endothelial cells and plays a significant role in the formation of blood clots. Structurally, FVIII’s domains are organized as A1-A2-B-A3-C1-C2. The absence or deficiency of FVIII in the bloodstream gives rise to Hemophilia A; an X-linked bleeding disorder affecting 1 in 5000 males worldwide. To combat this deficiency, patients undergo FVIII replacement therapy which involves frequent injections of FVIII into the bloodstream in the form of blood, plasma, or protein concentrates. Although effective, this treatment commonly results in the development of anti-FVIII inhibitory antibodies in approximately 20-30% of …
Investigating Kīlauea’S 2018 Offshore Lava Emplacement Through Hydroacoustic Data, Olana Costa
Investigating Kīlauea’S 2018 Offshore Lava Emplacement Through Hydroacoustic Data, Olana Costa
WWU Graduate School Collection
The 2018 eruption of Kīlauea Volcano produced an unprecedented volume of lava, creating 3.5 km2 of new land on Hawai`i’s Big Island (Soule et al., 2021). Lava expelled from the Ahu`aila`au vent (originally called Fissure 8) traveled ~13 km to where it entered the ocean. Over half of the lava erupted in 2018 was emplaced offshore where it produced four new submarine lava deltas (Soule et al., 2021). In response to the eruption, a network of 12 ocean-bottom seismometers (OBS) with attached hydrophones was deployed on Kīlauea’s submarine south flank. Ten of the instruments successfully recorded data from July …
A Characterization Of Hyporheic Temperatures With Applications For Salmon Habitat Restoration In A Thermally Impaired River, Sydney Jantsch
A Characterization Of Hyporheic Temperatures With Applications For Salmon Habitat Restoration In A Thermally Impaired River, Sydney Jantsch
WWU Graduate School Collection
This thesis project is part of an ongoing study assessing the effectiveness of a potentially innovative habitat restoration strategy for Pacific salmon in thermally impaired rivers. This strategy uses engineered log jams (ELJs) to create pockets of cool-water refuge by forming deep scour pools and promoting localized upwellings of shallow subsurface (i.e., hyporheic) water. This project seeks to characterize the relationship between hyporheic temperature and overlying surface stream temperature to elucidate the extent to which hyporheic upwellings can deliver cool water to ELJ-formed pools during the summer low-flow season. Among six sites within a 2.7 km-long study reach on the …
Visual Characteristics Of Walleye Pollock And Chinook Salmon: Modeling Theoretical Visual Space And Target Contrast Of Trawling Materials In The Bering Sea, Rebecca Haehn
WWU Graduate School Collection
Walleye pollock (Gadus chalcogrammus) and Chinook salmon (Oncorhynchus tshawytscha) are economic and cultural resources in Alaska. Chinook salmon bycatch is a large concern within the pollock fishery. Current strategies to reduce salmon bycatch include modifying trawl gear by implementing artificial light near or on escapement panels to increase salmon escapement. The visual characteristics of pollock and Chinook salmon were investigated to understand the perception of trawl gear. The visual pigments of each species were measured using microspectrophotometry (MSP). Pollock were dichromats with spectral sensitivity ranging from 449nm–518 nm and Chinook salmon were trichromats with sensitivity ranging …
Kinetic Analysis Of The Grafting Thermal Ring-Opening Polymerization Reaction Of Benzoxazine With Sulfonyl-Ester Functionalized Polymers, Tawakalt Adetoun Akinjobi
Kinetic Analysis Of The Grafting Thermal Ring-Opening Polymerization Reaction Of Benzoxazine With Sulfonyl-Ester Functionalized Polymers, Tawakalt Adetoun Akinjobi
WWU Graduate School Collection
This project will explore the fundamental mechanistic details and kinetics of a grafting polymerization reaction that occurs with blended benzoxazine monomers (or resins) and polymers functionalized with reactive sulfonyl-ester leaving groups [such as tosylate (Ts), nosylate (Ns) or mesylate (Ms) groups]. Isoconversional analysis (ICA) is one of the most important methods for establishing the kinetics of the complex reactions associated with curing thermosets. In the case of ICA, activation energy is measured at fixed values of reaction conversion.26 For thermosets the data are typically based on differential scanning calorimetry (DSC). The combinatorial approach not only provides uncertainty associated with …
Does Sediment Supply Impact The Threshold For Initial Sediment Motion In Natural, Gravel Bedded Streams?, Emily Loucks
Does Sediment Supply Impact The Threshold For Initial Sediment Motion In Natural, Gravel Bedded Streams?, Emily Loucks
WWU Graduate School Collection
Sediment transport in river channels control channel morphology, streamflow, and benthic ecosystems. Predicting sediment transport rates through a channel is required for sediment management for stream restoration and aquatic habitat assessment. The critical Shields stress (τ*c), is a dimensionless parameter used in sediment transport models that characterizes the river bed surface shear stress required to initiate sediment motion. The τ*c is typically assumed constant in transport models, yet compilations of field data have shown that τ*c can vary wildly, causing sediment transport models to over- or under-predict fluxes by an order of magnitude or more. Understanding …
Paleomagnetic Determination Of Vertical Axis Block Rotation Near The Doty Fault In Southwestern Washington, Charles Linneman
Paleomagnetic Determination Of Vertical Axis Block Rotation Near The Doty Fault In Southwestern Washington, Charles Linneman
WWU Graduate School Collection
In this paper I present the results of paleomagnetically derived vertical axis rotations (VARs) of sites in two different flows of the Columbia River Basalt (CRB) – the 16 Ma Sentinel Bluffs member of the Grande Ronde flow and the 12 Ma Pomona Member of the Packsack Lookout – near the Doty fault in southwestern Washington. In two field seasons, I collected 99 cores from 14 sites, 11 in the Grande Ronde flow and three in the Pomona member flow. Of the 227 specimens that I demagnetized, 212 had well-defined magnetic directions. Positive fold and reversal tests results confirm the …