Describing functions have traditionally been used to obtain the
solutions of systems of ordinary differential equations. In this
work the describing function concept has been extended to include
nonlinear, distributed parameter partial differential equations. A
three-stage solution algorithm is presented which can be applied to
any nonlinear partial differential equation....
The removal of microbial populations from potable water has been a practice with great importance towards public health, as it has resulted in the reduction of literally millions of cases of infectious disease. In the United States, pathogenic organisms are most commonly removed from drinking water through the application of...
Published March 1982. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
The purposes of this study were:1) to review the land use history of Oak Creek watershed since European settlement. And 2) to consider the human-caused impacts and their effects associated with different land uses. The study area was classified into three land use patterns: residential,agricultural, and forested areas.Since the European...
In the year 2007, the worldwide energy consumption accumulated to a total of 16.5 billion MWh. While the resources of conventional energy production cause environmental damage, renewable energy sources like solar or wind power offer a solution to substitute for coal or nuclear generated power. Countries like Denmark and Spain...
Little research has investigated males’ reactions to non-objectified media images of women, including those that depict women in instrumental activities like playing a sport. Using a survey methodology, this study examined U.S. adolescent boys’ open-ended responses to images of performance athletes, sexualized athletes, and sexualized models. Participants were 104 adolescent...
Developed coastlines provide a variety of recreation opportunities to coastal residents and visitors but are also the first line of defense for oceanfront development against chronic hazards like erosion and sea level rise. In the Pacific Northwest of the United States, oceanfront homes also face an additional severe but very...
When Biosand filters cannot be constructed with crushed quarry rock due to resource limitations, a suitable alternative filter media is needed. In this research, two crushed quarry rock alternatives were examined. Three bench-scale Biosand filters with crushed rock, beach sand, and heat-treated beach sand media were simultaneously dosed with Willamette...
There is a growing need for individualized instructional designs in 4-year institutions due to: 1) growing undergraduate enrollment trends across the U.S., 2) broader diversity in students backgrounds, and 3) the growing prevalence of asynchronous remote learning. With the growth in computer technology in education, tools such as adaptive intelligent...
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Julie D. Tucker Milo D. Koretsky
There is a growing need for individualized instructional
Continental shelf sediments are sinks for dissolved oxygen and sources of many major and minor nutrients required for oceanic surface primary production, resulting in a strong coupling between benthic and pelagic biogeochemical cycling. However, the influence and spatiotemporal variability of benthic remineralization on bottom-water chemistry and the supply of nutrients...
We study a class of two-generator two-relator groups, denoted J[subscript n](m, k), that arise in the study of relative asphericity as groups satisfying a transitional curvature condition. Particular instances of these groups occur in the literature as finite groups of intriguing orders. Here we find infinite families of non-elementary virtually...
This dissertation aims to elicit how a neo-colonial context shapes maternal and infant heath (MIH) outcomes by describing how they are socially, politically, historically, and culturally produced. Using a multi-level critical biocultural, medical anthropological research approach, the purpose of this research was to investigate maternal stress in the United States...
Writing a program that performs well in a complex environment is a challenging task. In such problems, a method of deterministic programming combined with reinforcement learning (RL) can be helpful. However, current systems either force developers to encode knowledge in very specific forms (e.g., state-action features), or assume advanced RL...
Coral reefs have become vulnerable to climate change, with mass bleaching events, the loss of symbiotic algae (Symbiodiniaceae), increasing in both frequency and severity. As climate change continues to threaten the persistence and existence of coral reefs around the world, the biggest question posed for coral reefs is “can they...
In recent years, several interrelated forces—prolonged drought, growing populations, height-ened environmental protections, sustained agricultural use, and hydrologic alterations due to climate change—have increased pressure on water users in the Western United States, where the agricultural sector accounts for up to 90% of total water withdrawals. Technology im-provements developed since the...
Wetlands play an important role in our social and economic well being. Many
services wetlands provide, such as wildlife habitat, recreation, and aesthetics, are
collective goods. Because these services are not represented in a market, an over supply
of wetlands converted to other uses and an under supply of protected...
Malolactic fermentation (MLF) is important in the production of wines as it reduces acidity through the conversion of malic acid to lactic acid. However, successful MLF can be difficult to achieve due to yeast antagonism of the bacterium responsible for
the secondary fermentation, Oenococcus oeni. In particular, yeast produced sulfur...
The reason for the initial rise in atmospheric
CO₂ during the last deglaciation remains unknown. Most recent
hypotheses invoke Southern Hemisphere processes such
as shifts in midlatitude westerly winds. Coeval changes in
the Atlantic meridional overturning circulation (AMOC) are
poorly quantified, and their relation to the CO₂ increase is
not...
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overturning decline and its role in atmospheric
CO₂ rise inferred from carbon isotopes (δ¹³C)
Schmittner, A
The purpose of this study is to explore, through their own voices, the higher
education experiences of selected urban American Indian females in California
community colleges. This study is an attempt to identify pathways to academic
success by teasing out college practices and support systems that help Native
women navigate...
The National Park Service has a dual mission of providing public access to exceptional natural resources, but in a manner such that these resources are left “unimpaired for the enjoyment of future generations.” Human activities in parks undoubtedly affect wildlife, but the degree to which such activities cause impairment is...
Diversity literary awards and other sources were used to create a list of high-quality titles written by and about underrepresented groups. This list was used to assess the diversity and inclusiveness of the library collections of a land-grant university. Gaps in the collection and acquisition processes were identified and will...
Motor skill deficits are present and persist in school-aged children with autism
spectrum disorder (ASD; Staples & Reid, 2010). Yet the focus of intervention is
on core impairments, which are part of the diagnostic criteria for ASD, deficits in
social communication skills. The purpose of this study is to determine...
Oregon Biography Index is intended to serve primarily as a starting point in locating biographies of Oregonians. We have indexed 47 historical volumes which are either entirely devoted to biographies or have large self-contained biographical sections. The profiles in the books vary widely in accuracy and detail. Birth dates of...
Remote aquatic ecosystems are exposed to an assortment of semivolatile organic compounds (SOCs) originating from current and historic uses, of local and global origin. Here, a representative suite of 57 current- and historic-use pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons were surveyed in the plasma of the western pond turtle...
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contaminants in western pond turtles in remote habitat in
California
Erik Meyer a, *, Evan A. Eskew b, Leah
Large quantities of unused heavy oil and residual waste products from the petroleum refining industry were deposited in on-site landfills, pits, and lagoons, prior to the promulgation of regulations governing their disposal and technology development that would further utilize and/or recycle these materials.
Contacting petroleum products with sulfuric acid for...
The first results obtained with the Lamont Pumping SeaSoar (LPS), a combination measurement and sampling platform towed by a research ship at speeds of 6–7 kt, are presented. The system allows not only measurement of a suite of oceanographic parameters with in situ sensors, but also delivery of seawater samples...
This paper discussed the human electrocardiogram, the instrumentation
used to graphically record it, and the design and performance
of a specialized system for vector cardiography: the Vector Electrocardioscope
(VECS) System. The introduction reviews in considerable
detail the pertinent known physiology of the heart, especially the
electrophysiology responsible for the genesis...
The major focus of this research was to examine the factors, both
instructional factors and student factors, that influence student
gains in economic knowledge in economic education. This study sampled
twelfth grade students from randomly selected high schools in the
Williamette Valley of Oregon. The stepwise regression analysis was
used...
Medication error rates have long been a subject of interest
among the pharmaceutical, nursing, and medical professions. The
basic purpose of medication error studies has been to discover the
quantity and type of errors which exist, thus enabling the investigator
to evaluate the relative safety of various drug distribution
systems...
The sigma convergence method was introduced by G. Nguetseng for studying deterministic homogenization problems beyond the periodic setting and extended by him to the case of deterministic homogenization in general deterministic perforated domains. Here we show that this concept can also model such problems in more general domains. We illustrate...
The intergenerational transmission of school adjustment was explored in a sample of 213 children and their fathers. The fathers were participants in a longitudinal study that began when they were in the fourth grade, and their children have been assessed at the ages of 21 months and 3, 5, and...
This qualitative study examined organizational change including the
necessary steps that a large school district took in planning and implementing a
reform effort. This project told a story of one school district's experience.
The study covered a five year period from 1990 to 1995 in the 30,000 student
Salem-Keizer School...
This study focused on users' emotional responses to a sustainable and a non-sustainable interior environment. Emotional reactions toward interior environments were tested by having subjects complete a survey. The survey tested users' emotional reactions with a mixed methods approach by including both qualitative and quantitative questions. The scope of this...
A steady gas convection model of heat transfer to a horizontal
cylinder immersed in a gas fluidized bed is presented. Contributions due to flow within
attached bubbles as well as the interstitial voids are
included. The interstitial flow is approximated as flow within a series
of double cusped channels and...
Many ecologists and environmental scientists witnessing the scale of current environmental change are becoming increasingly alarmed about how humanity is pushing the boundaries of the Earth’s systems beyond sustainable levels. The world urgently needs global society to redirect itself toward a more sustainable future: one that moves intergenerational equity and...
Pacific harbor seals (Phoca vitulina richardii) are one of Oregon’s most common coastal predators, numbering between 10,000 and 12,000 individuals (Brown et al. 2005b). They consume more than 149 species or types of marine prey within the Pacific Northwest, which include a large variety of commercially important fisheries species. Despite...
Cold seep communities with distinctive chemoautotrophic fauna occur where hydrocarbon-rich fluids escape from the seabed. We describe community composition, population densities, spatial extent, and within-region variability of epifaunal communities at methane-rich cold seep sites on the Hikurangi Margin, New Zealand. Using data from towed camera transects, we match observations to...
The Mt. Scott watershed in northern Clackamas County, Oregon is an urban watershed that lies inside the Portland metropolitan urban growth boundary. Urbanization of the watershed began in the early 1970s and has recently accelerated. A landscape level analysis of the urbanization process was combined with the results of a...
Research has established that poor outcomes are the future for those without a
high school diploma--yet students continue to drop out and become members of
that population. The purpose of this qualitative study was to investigate the
experiences and perceptions of individuals who did not complete high school
within the...
Construction sites are responsible for generating a high concentration of pollutants in surrounding air. Emission level can be different depending on the materials used for the construction. One of the methods for quantifying air pollution is to measure particulate matters (PM) emitted on construction sites. This study aims to determine...
This dissertation consists of three essays on meta-analysis, benefit transfer and recreation use valuation. The first two essays were based on the sportsfishing valuation literature in the US and Canada while the third essay was based on a study
site in the Philippines and selected study sites from the US....
Daily and seasonal habitat use by Roosevelt elk was investigated
in the Oregon Coast Range on managed, public forestland. Over 3,700
locations of 6 radio-collared cow elk were recorded during 12 consecutive
months. Two elk formed part of a north band and 4 elk were
part of a south band....
The objectives of this study were to evaluate environmental
factors influencing use of several plant communities by cattle, elk
and deer; determine under story production by plant species and the
amount utilized by cattle, elk and deer in certain plant communities;
evaluate the interactions of range use between cattle, elk...
This dissertation is organized in accordance to the Manuscript Documentation Dissertation format required by Oregon State University. Chapter 1 provides a general overview of Alzheimer’s disease, defines AD as marginalized population, and explains the relevance and characteristics of qualitative research. Also, Chapter 1 provides an overview of Manuscript 1 (Chapter...