Diet variation among individuals within populations is widespread. Often diet differences among individuals are attributable to obvious differences among individuals such as age, sex, or morphology. However, growing evidence suggests that individual diet variation is also common among seemingly identical individuals within populations. This phenomenon has been termed individual diet...
Benthic infaunal communities are important components of coastal ecosystems. Understanding the relationships between the structure of these communities and characteristics of the habitat in which they live is becoming progressively more important as coastal systems face increasing stress from anthropogenic impacts and changes in climate. To examine how sediment characteristics...
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Corresponding author
KyleE. Coblentz,
kyle.coblentz@science.oregonstate.edu
Academic editor
Linsheng Song
A long-standing debate concerns how functional responses are best described. Theory suggests that ratio dependence is consistent with many food web patterns left unexplained by the simplest prey-dependent models. However, for logistical reasons, ratio dependence and predator dependence more generally have seen infrequent empirical evaluation and then only so in...
Benthic infaunal communities are important components of coastal ecosystems. Understanding the relationships between the structure of these communities and characteristics of the habitat in which they live is becoming progressively more important as coastal systems face increasing stress from anthropogenic impacts and changes in climate. To examine how sediment characteristics...
Benthic infaunal communities are important components of coastal ecosystems. Understanding the relationships between the structure of these communities and characteristics of the habitat in which they live is becoming progressively more important as coastal systems face increasing stress from anthropogenic impacts and changes in climate. To examine how sediment characteristics...
An electrically driven propellant pump (HALE E-Pump) was analysed and tested to determine its viability for use in a bi-propellant launch vehicle for the High-Altitude Liquid Engine (HALE) student rocket team at Oregon State University (OSU). The pump, manufactured in 2022 by students in OSU machine shops, was hydrostatically tested...
Vacuum arc remelting (VAR) is a secondary melting process for exotic alloys. The main purpose of this process is to increase the input ingot’s physical and chemical homogeneity. This is accomplished through the application of a high current that melts the material through the emergence of electrical arcs that induce...
Modern scientific and engineering problems often require simulations with a level of resolution difficult to achieve in reasonable amounts of time—even in effectively parallelized programs. Therefore, applications that exploit high performance computing (HPC) systems have become invaluable in academia and industry over the past two decades. Addressing the questions that...
Simulations of combustion and reacting flows often encounter stiffness in the equations governing chemical kinetics. Explicit solvers for these ordinary differential equations offer low computational expense, but typically cannot efficiently handle stiff systems. In contrast, implicit methods demand greater expense but offer unconditional stability—as a result, most reactive-flow solvers rely...
Real transportation fuels contain a wide range of hydrocarbon species, and this complexity poses challenges for modeling. Surrogates with a simpler blend of hydrocarbon reference fuels can approximate the physical and chemical characteristics of real fuels and enable practical simulation of the reacting flows that occur in engines and combustors....
Engineering applications often require fast, accurate solutions of fluid flow around freely moving bodies. The massive parallelism enabled by graphics processing unit (GPU) architecture enables high performance, offering a promising alternative to traditional solver acceleration via multicore central processing units (CPU). However, fully harnessing GPU parallelism requires specialized algorithms and...
Modeling elementary chemical reactions in ocean fluid dynamics simulations requires significant computing resources, which can be diminished with model reduction techniques. Submesoscale ocean turbulence and biogeochemical reactions in the ocean occur on approximately the same time scale, 105 seconds. This similarity in time scales indicates a strong coupling between these...
Implementing multicomponent diffusion in numerical combustion studies is computationally expensive due to the challenges involved in computing diffusion coefficients. As a result, mixture-averaged diffusion treatments or simpler methods are used to avoid these costs. However, the accuracy and appropriateness of the mixture-averaged diffusion model has not been verified for three-dimensional...
The aerospace industry uses chemical kinetic models when designing propulsion systems to acquire specific details about the rate of chemical reactions, heat release, and combustion stability. These models, however, are too large and stiff to be useful as they can take weeks to run computations on. The pyMARS python package...
Due to global warming wildland fires are increasing in frequency and severity. In the case of wildland fires, the major modes of combustion occur include smoldering combustion and flaming combustion. Smoldering combustion occurs most commonly in porous fuels like peat, forest duff, and woody fuels, which are available in abundance...
Accurately modeling the chemistry of conventional and alternative liquid transportation fuels in combustion technology is vital to predicting important quantities such as the burning rate, heat release, and pollutant emissions. However, incorporating detailed chemical kinetic models into reactive-flow simulations poses a significant challenge due to the associated high computational expense...
For this project, we designed a soot modeling software to produce a full particle density function. This model uses the Direct Simulation Monte Carlo with a full conditioning particle selection method to capture soot nucleation and coagulation in a diffusion flame. We investigate the use of graphic processing units as...
The High Altitude Liquid Engine (HALE) team is developing of a 2000 lbf thrust liquid propellant engine for a flight vehicle capable of breaching the Karman Line (100 km in altitude). As part the development of this flight vehicle, this research focuses on the design and characterization of a novel...
As carbon emissions are negatively impacting ecosystems across the globe, researchers are in a race against time to provide cleaner and more eÿcient power. Detonation engines can help meet the increasing demands for cleaner and more eÿcient power generation by providing an alternative means to use oxy-fuel combustion for carbon...
Small hydrocarbon particles such as soot and soot precursors pose a serious threat to human health and Earth's climate. Understanding the mechanisms by which soot particles form and grow is the first step to reducing the prevalence of these particles. Computational simulations are used to investigate combusting systems which are...
High-potential molecules derived from biomass sources may suitably replace or supplement traditional nonrenewable hydrocarbon fuels to reduce pollution and fuel processing costs. Due to expensive and time-consuming property testing, models that predict key properties from optical data would initially vet potential additives before investment and bench-scale testing. Attenuated Total Reflection...
In this work, I developed a six degree of freedom flight simulator specific to liquid engine launch vehicles. This flight simulator improves upon available software by accounting for liquid engine specific phenomena such as tank pressurization, liquid engine performance, and center of gravity modeling. Additionally, I implemented methods for optimization...
In this paper, I present the design of Mira 2, a small-scale, liquid bipropellant rocket engine, with a specific focus on its oxidizer-centered pintle injector. Building upon the valuable lessons and insights gained from the empirical testing of its predecessor, Mira 1, the Mira 2 engine incorporates several improvements and...
Smoldering combustion in wildland fires is a critical phenomenon that needs in-depth study because it can initiate with weaker ignition sources, can persist for long periods, is difficult to suppress, and can transit to flaming combustion. Cellulose, hemicellulose, and lignin are the major organic constituents within biomass, in varying proportions...
The control of feral goats (Capra hircus) and relevant aspects of their biology were studied on Aldabra Atoll, Republic of Seychelles, from October 1993 - May 1994 and November 1994 - May 1995. A total of 832 goats were killed on Aldabra using both the Judas goat technique and traditional...
A population of Spermophilus beecheyi was studied to determine
patterns of individual spacing, behavioral interactions among different
sex and age classes, and the relationship between aspects of S. beecheyi
social structure and sociality to those of other sciurids. Research was
conducted on a population of squirrels living in an abandoned...
Feral goat (Capra hircus) populations adversely impact native insular biota and physical habitats worldwide. The effectiveness of the Judas goat technique for eradicating remnant feral goats was studied on San Clemente Island (SCI), California from June 1989 through April 1991. By April 1991, 263 feral goats were killed on SCI;...
Deforestation and forest fragmentation are the primary threats to the habitat
of endangered lion-tailed macaques, Macaca silenus, in Karnataka, India. Landsat
satellite images of northwest Karnataka, India, from 1977 and 1990 were analyzed.
Two study sites, measuring 16.35 x 19.14 km (31,213 ha) and 14.34 x 21.44 km (30,561
ha),...
A cow-calf herd of Roosevelt elk (Cervus elaphus roosevelti)
resident to Indian Creek Research Center (ICRC), Oregon was observed
June-August, 1985 and March-August, 1986. Cows at ICRC reproduced in
alternate years; cows with calves led the herd a significantly
greater number of times than cows without calves (1985, P <...
The potential for Rocky Mountain mule deer (Odocoileus hemionus hemionus)
to host exotic chewing lice (Damalinia (Cervicola) sp.) believed to cause deer hair
loss syndrome in Columbian black-tailed deer (Odocoileus hemionus columbianus),
was investigated in captive deer held in pens at E.E. Wilson Wildlife Area, Corvallis,
Oregon from March 2004...
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Bruce E. Coblentz
The potential for Rocky Mountain mule deer (Odocoileus hemionus
Characteristics of minke whale (Balaenoptera acutorostrata) habitat at the head of the Laurentian Channel in the St. Lawrence Estuary, Canada were identified by quantifying environmental and temporal habitat variables and comparing them to the presence or absence of minke whales during the summer of 1996. Identification photographs of minke whales...
Forage availability, diets, distribution, and productivity were
compared for Roosevelt elk, Cervus elaphus roosevelti, using improved
(i.e. seeded, fertilized, and grazed) and untreated areas of the Oregon
Coast Range. Seasonal forage availability was substantially different
on 1-year-old improved and untreated clearcuts, but the differences
diminished by clearcut age 4 and...
The garibaldi, Hypsypops rubicundus, is a sexually monochromatic pomacentrid found in rocky subtidal areas of Southern and Baja California. During the spawning season, males attempt to attract females to a nest of red algae located within individually defended territories. Females were observed to enter the nests of several males before...
I investigated the population attributes and habitat
selection of mountain beaver (Aplodontia rufa) recolonizing
clearcuts in the Coast Range mountains of Polk and Lincoln
counties, Oregon between June 1989 and August 1990. The
population characteristics of colonizing mountain beaver
were evaluated in 12 stands of 3 types: 1-year-old
clearcuts assumed...
California bighorn sheep (Ovis canadensis californiana) were studied on Hart Mountain, Oregon, during the summer and fall of 1976, and the spring of 1977. The population consisted of a minimum of 196 sheep in June, 1977. The high number of lambs observed and high lamb:ewe ratios throughout both years of...
A herd of California bighorn sheep (Ovis canadensis californiana),
re-introduced to the area of Hell Creek on the Sheldon National
Wildlife Refuge in northwestern Nevada, was studied from 15 June 1978
to 20 August 1980.
Major vegetation and physiographic types were delineated and
described. Habitat preferences were determined from field...
A study conducted May 1978-December 1980 determined that the present geographic range of Columbian white-tailed deer, Odocoileus virginianus leucurus, (CWTD) in Douglas County, Oregon encompassed 1199km2. The area was predominately a Quercus woodland community, typical of the Interior Valley Zone of western Oregon. The CWTD distribution
was not contiguous throughout...
Recently the National Park Service has proposed raising fence heights to exclude mouflon sheep (Ovis musimon) from conservation areas at Hawai'i Volcanoes National Park. Concern over previous mortality of Hawaiian Petrels (Pterodronia sandwichensis) due to collision with fences prompted this study to quantify the potential effects of raising fence heights...
A feral pig population on Santa Catalina Island, California, was
studied for 17 months beginning in July 1980. Density was estimated
to be 21 to 34 pigs/km² (95% confidence interval) using capture-recapture
techniques. Dry season home ranges determined from
radio-telemetry data were small and differed significantly between
boars and sows....
I studied sexual segregation in mule deer (Odocoileus
hemionus) and white-tailed deer (Q. virginianus) in
different environments and at different population
densities to test the hypothesis that sexual segregation
occurs in ungulates as the result of different
reproductive strategies; females select habitat and behave
in manners primarily designed to promote...
Aspects of bison ecology and behavior were studied in the Henry
Mountains, Utah during summer 1977 and summer 1978. Foraging
distributions of bison and of cattle were compared to elevation, slope,
horizontal distance from water, vertical distance from water, aspect,
and availability of preferred forage. The effect of bison-cattle
interactions...
The movements, habitat use, and activity patterns of black-tailed deer in western Oregon, and the influence of suburban housing developments on the behavior of deer in the area, were studied and described. Radio telemetry, spotlight censusing, and a resident questionnaire were used to document the behavior of deer. Radio telemetry...
The purpose of the study was to analyze the possible combination of cooling systems, which are film cooling and regenerative cooling, and obtain the initial estimates of possible temperature reduction. The analysis was conducted in Ansys Fluent. The methodology includes four main steps that are the following: flow simulation, combustion...
Carbon tetrachloride (CT) and chloroform (CF) were transformed in batch reactor experiments conducted with anaerobic dechlorinating cultures and supernatant (ADC+S) harvested from continuous flow reactors. The Evanite (EV-5L) and Victoria/Stanford (VS-5L) cultures capable of respiring trichloroethene (TCE), 1,2-cis-dichloroethene (cDCE), and vinyl chloride (VC) to ethene (ETH) were grown in continuous...
The steroid hormone estrogen plays a crucial role in regulating certain mammalian tissues, especially female reproductive systems. Estrogen effects physiological changes in the cell by altering transcription activity for certain target genes, as a consequence of interactions between estradiol-17β (E2) and its nuclear receptor (nER). This mechanism of cellular control...
High Temperature Gas Reactors (HTGR) are a type of power plants that can provide industrial process heat and high efficiency, carbon-free electricity. The High Temperature Test Facility (HTTF) has been designed to provide data that can be used for the validation of system codes and verification of passive safety features...
Both conflicts and new identities result when indigenous' traditional values of landscape and resource management are superimposed with federal governments' management of archaeological and forest resources in federally designated protected areas. This thesis examines the relationship and discourse between two Cuicatec towns in Oaxaca, Mexico and three Mexican government agencies...