One in four Ecuadorians do not have access to health services; while more than two-thirds have no health insurance and insufficient resources to pay for the health care services they might require. The following three studies examined utilization of health care services using Andersen’s Health Care Utilization Behavior Theory. Secondary...
School administrators are required by law to report suspected cases
of child abuse. They create serious legal and moral consequences for their
school districts when they fail to report suspicions of child abuse occurring
in the school setting. Studies consistently find that child sexual abuse is
under-reported and that allegations...
This dissertation focuses on two core aspects of remote sensing: (a) interpretation of the remotely sensed data to identify and characterize sea surface features of interest, and (b) the quantitative analysis of previously characterized features to produce robust estimates of geophysical variables. Specifically, these aspects are addressed in the context...
Polyoxometalates are a rapidly growing class of discrete metal oxide clusters with a wide range of applications including functional materials. These anionic clusters of the group V and VI transition metals are inexpensive and non-toxic. Within group V polyoxometalates, niobium and tantalum chemistry has been underdeveloped owing to their unique...
The function of a protein is defined by its three-dimensional structure, and in understanding the three-dimensional structure of a protein, we gain an understanding of its function and mechanism. Protein structures, especially at high resolution, can provide detailed insights into many elements of enzyme function and catalysis – identifying residues...
The silviculture of mixed dipterocarp forests of Peninsular Malaysia can potentially be improved by developing quantitative tools and guidelines for this forest type. This thesis addresses three key objectives; 1) to test the hypothesis that a maximum size-density relationship can be identified in hill dipterocarp forests of Peninsular Malaysia, 2)...
Eight postemergence herbicides were evaluated to determine
their influence on the incidence and severity of take-all disease
caused by the fungus Gaeumannomyces graminis var. tritici in winter
wheat. Mecoprop ((+)-2-(4-chloro-2-methylphenoxy)propanoic acid),
difenzoquat (1,2- dimethyl- 3,5- diphenyl -1H- pyrazolium), dinoseb amine
(amine salt of 2-(1-methylpropy1)-4,6-dinitrophenol), and diclofopmethyl
(methyl ester of (+)-2-[4-(2,4-dichlorophenoxy)...
The Purpose of the Study
The central purpose of this study was to determine if certain
personality characteristics differ between community college persisters
and those who drop out of school. The following 12 a priori
hypotheses involving six Adjective Check List personality scales were
tested:
1. Male persisters would have...
Investigations with ram semen were conducted to develop procedures
of cyrogenic preservation that would provide long-term
retention of fertilizing capacity in ram spermatozoa.
An isotonic extender consisting of egg yolk, sodium citrate,
lactose, glycerol, and a broad spectrum antibiotic was selected from
among several extenders tested in pilot studies. Using...
The purpose of this study was to compare the perceptions
of the university environment of four selected groups
of residence hall students at Oregon State University:
male elected residence hall leaders (N -52), male non-leader
residence hall students (N-52), female elected residence
hall leaders (N-53), and female non-leader residence hall...
The Purposes of the Study
The primary purpose of this study was to identify common professional
education competencies needed by public school district
vocational education leaders. Other purposes were to (1) determine
if significant differences existed in vocational education leadership
competencies among respondents as categorized by state, type of
position...
Instrumental and radiochemical neutron activation analyses supported by electron microprobe mineral analyses (Paul Warren, University of New Mexico) and petrographic observations are presented for approximately forty individual clasts separated from the Kapoeta howardite. These clasts are classified into eucritic, cumulate-like, mafic (plagioclase ± olivine-bearing pyroxenites), pyroxenite, polymict and/or metal-rich and...
Two objectives of this research were to identify fungi which are
mycorrhizal with western hemlock and to examine the ecology of hemlock
mycorrhizal fungi indigenous to outplanting sites. Another objective
was to evaluate the effectiveness of mycorrhizal inoculation in
improving the performance of outplanted hemlock seedlings.
A list of over...
Estimates of heritability and associations of tiller number,
seed number, seed weight, and seed yield were determined in two
groups of tall fescue. Group E was early maturing and had eight
parental clones, while group I was intermediate in maturity and had
nine parental clones. The parents and five progeny...
Engineers have long been inspired by nature's flyers. Such animals navigate complex environments gracefully and efficiently by using a variety of evolutionary adaptations for high-performance flight. Biologists have discovered a variety of sensory adaptations that provide flow state feedback and allow flying animals to feel their way through flight. A...
The theory and ways of applying a new electroanalytical detectior
method were developed. The method, called galvanovoltammetry,
consists of the measurement of current from the bipolar electrode of
a three electrode cell which consists of a working electrode and a
counter electrode, between which a constant current is applied, and...
This dissertation focuses on the life of Dixy Lee Ray as it examines important developments in marine biology and biological oceanography during the mid twentieth century. In addition, Ray's key involvement in the public understanding of science movement of the 1950s and 1960s provides a larger social and cultural context...
A new group of lead free piezoelectric perovskite solid solutions, (1-x)Bi(B'B")O₃-xABO₃, were obtained via solid-state processing techniques. The solubility of unstable perovskite Bi(B'B")O₃ compounds into stable perovskite compounds was found to be related to the tolerance factor of the ABO₃ perovskite endmembers. The morphotropic phase boundary (MBP) in perovskite solid...
Fission product yields (FPYs) are used for a wide range of applications including nuclear fission theory, nuclear reactor design, reactor antineutrino anomaly, stellar nucleosynthesis, and nuclear forensics. These applications rely on FPYs that were last evaluated in 1993, which included measurements from all over the world up until 1993. In...
Gamma-gamma directional correlations were measured
in Ba¹³⁴ at ten angles between 90 degrees and 180 degrees in ten
degree increments using a scintillation spectrometer. The spectrometer
which used NaI crystals, differential energy selection,
and standard coincidence techniques was tested by measuring the
directional correlation of the two cascade gamma rays...
Nuclear techniques such as perturbed angular correlation (PAC) sample the hyperfine interactions of a large number of probe atoms in specific crystallographic sites. Real crystals contain static defects producing a distribution of electric field gradients (EFGs) that add to the ideal EFG of the crystal at any given probe site....
Questionnaires were used in a survey of Oregon farmers to determine
how they select and use herbicides on wheat.
Farmer's decisions were evaluated on the basis of their ability to:
select the proper herbicide treatment for their weed problem and to
make application at the proper time.
Questionnaire scores indicated...
The herbicide rate required to reduce growth by 50% (GR₅₀) of 11
cultivars of red fesue (Festuca rubra L. and F. rubra ssp. commutata)
and for four cultivars of bentgrass (Agrostis tenuis Sibth. and A.
stolonifera L. var. palustris) to sethoxydim (2-[1-(ethoxyimino)
butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one) was
determined in greenhouse and laboratory experiments....
PURPOSE OF THE STUDY: The study examined administrator and faculty perceptions
toward staff development needs and ascertained the
differences which exist between the reported staff development
needs of full-time community college instructors within
the state of Oregon.
OBJECTIVES OF THE STUDY:
The three objectives identified for this study were:
1....
A study was conducted to determine effects of year and season on diet quality of beef cattle grazing northern Great Basin rangelands from 1990 to 1993. Forage quality was high early in the growing season, then declined as seasons progressed (P<.05). Plant chemical composition was higher early in the growing...
The purpose of this research study was to examine the impact of the
consulting teacher model on referral and verification rates to special
education. A population of schools which implemented the model
(N = 17) was compared with a randomly selected comparison group of
schools which did not (N =...
A study investigating the effect of sheep stocking
density and grazing duration on forage intake, grazing
efficiency, dietary selectivity and subsequent forage
accumulation in tall fescue(Festuca arundinacea)-
subclover(Trifolium subtaranium) pastures was conducted
near Corvallis, Oregon during early and late spring in
1988 and 1989. Grazing treatments were 2, 6, and...
The production of cement and concrete results in the production of large amounts of CO₂ emissions which can have significant negative environmental impacts. Using supplementary cementing materials (SCMs) as a cement replacement is an effective solution to reduce these negative environmental impacts, as most SCMs are waste by-products from other...
:
________________________________________________________________________
David Trejo
The production of cement and concrete results in the production of large amounts
The issue of chloride-induced corrosion of reinforcing steel in concrete and its economic impacts are well-known. Chlorides that cause reinforcement corrosion can be from constituent materials used to prepare concrete or can enter the hardened concrete when the structure is exposed to chloride environments. To minimize the risk of reinforcement...
The constituent materials of concrete often contain chlorides. The presence of chlorides in sufficient amounts can disrupt the passive layer, also known as the passive film, that protects the reinforcing steel in concrete. This disruption can lead to premature corrosion of the reinforcing steel in concrete. To minimize the risk...
This dissertation explores the structural dynamics of human understanding and particularly the concept of meaning and its connections to concepts of ultimate ground, necessity and contingency, language, and perception. It focuses on the history of the concept of meaning in early twentieth-century European physics and philosophy, through an analysis of...
Twenty-three bottom-trawl fish assemblages were identified from the relative biomass of
33 dominant species that occurred in the National Marine Fisheries Services' triennial
trawl surveys over the continental shelf and upper slope off California, Oregon, and
Washington from 1977 to 1992. The assemblages accounted for about 70% of the total...
Significant progress has been made over the past 20 years in developing models to estimate the service-life of reinforced concrete systems. The basic understandings of the mechanisms that control the transport of ions and moisture in concrete systems have been well researched and models for determining corrosion initiation, specifically chloride-induced...
Single-scattering tomography describes a model of photon transfer through a object in which photons are assumed to scatter at most once. The Broken Ray transform arises from this model, and was first investigated by Lucia Florescu, Vadim A. Markel, and John C. Schotland, [2], in 2010, followed by an inversion,...
To better understand the extreme local amplification of tsunami, the experimental investigation on counter-propagating solitary wave collisions over a horizontal bottom was conducted using the optical measurement techniques: Particle Image Velocimetry (PIV), and Laser Induced Fluoresce (LIF). Head-on collisions and oblique collisions of equal-amplitude as well as unequal-amplitude waves were...
Damage estimates to the built environment from tsunamis are important for disaster mitigation, including planning emergency response and recovery. This dissertation evaluates the damage states of buildings in a small urban coastal city, Seaside, Oregon, from tsunami hazards generated by a Cascadia Subduction Zone (CSZ) event. This study is separated...
Tidal marshes are dynamic ecosystems that are threatened by climate change and sea-level rise. To characterize baseline condition and historic climate sensitivities, and improve projections into the future, new methods are required that integrate data from the field and remote sensing platforms. Marsh elevation response models can be calibrated with...
Surface transient storage (STS) and hyporheic transient storage (HTS) have functional significance in stream ecology and hydrology. Both provide refugia for aquatic communities and their longer mean residence times (compared to the main flow) increase the potential for biogeochemical reactions that can improve water quality. As STS and HTS have...
Since its discovery, the anomalous dielectric behavior of CaCu₃Ti₄O₁₂ (CCTO)
has drawn a great deal of attention for many possible applications in electronic
devices. The origin of the giant dielectric constant in CCTO was explained via an
internal barrier layer capacitor model, and it has been reported that the dielectric...
Community and technical colleges in the United States are experiencing an expansion of racial and ethnic diversity in students, faculty, and administrators. From 1996 to 2006, the number of Asian female college students increased 55.3%, from 13,184 to 20,477. The number of Asian male students increased 48.9%, from 9,731 to...
The aim of this research is to develop a fundamental understanding of the dominant defect species and the relevant defect equilibrium conditions for bismuth-containing perovskites to help guide the development of these materials for emerging applications. This is of paramount importance for many demanding applications, because ultimately the defect equilibria...
Relaxor characteristic of the solid solution (1-x)BaTiO₃-(x)Bi(Zn₁/₂Ti₁/₂)O₃ (BTBZT) was investigated in this research. X-ray diffraction technique and Raman spectroscopy revealed the crystal structure of BT-BZT at various compositions. For compositions with x ≤ 0.08, the solid solutions exhibited clear tetragonal symmetry and transitioned to pseudo-cubic symmetry as the content of...
A prototype real-time process monitoring emergency
classification expert system, RT/EM-CLASS, has been developed
for use at the Trojan Nuclear Power Plant. This knowledge-based
system features the integration of electronically sensed plant
data with the menu selection data representation of its
predecessor, EM-CLASS. This prototype demonstrates the
techniques required to acquire...
Of great benefit, but not limited to seafloor mineral
exploration, is a technique that fairly rapidly determines the
composition of a drilled vibracore (in a time comparable to the time
involved in obtaining the core). The rapid assessment is desired to
predict whether a given region warrants further exploration by...
A new x-ray source capable of operating at up to 80
watts has been designed and developed, and put to use with
the Oregon State University Cylindrical Electrostatic
Analyzer. The new source produces over four times the
photoelectron intensity of its predecessor, from gaseous
samples, and accommodates a wider selection...
The satellite structure ("shake-up") present in the X-ray
photoelectron spectra of several planar molecules containing
double bonds has been investigated in the gas phase.
This set consists of three five-membered heterocyclic
molecules, ethylene and two of its fluorinated analogs, and
benzene with three of its fluorinated analogs. In addition,
core...