We consider development of sand ripples in shallow water flows which do not reach an equilibrium height but have a time-varying ripple height that slowly reaches a maximum value and then is quickly destroyed by the fluid. A simple scenario to explain the time periodic behavior of the sand ripples...
We introduce a relativistic model for pion-nucleon scattering which includes an elementary
delta dressed by its decay. Crossing-symmetric single-particle exchange
is augmented by parametrized multiple-scattering interactions, with covariant sideways
form factors in both 3- and 4-field vertices. Causality is enforced by dispersion
relations. Unitary fits to observed on-shell amplitudes are...
We develop a technique to express the nucleon pole strength and bare mass in terms of renormalized quantities. Starting from a general unrenormalized self energy we determine the bare mass and the pole strength. For determining the pion content of the nucleon we discuss the leading renormalization loop. We relate...
A new method for evaluating the Lyapunov exponent for a Hamiltonian system
involves a spatial evaluation, rather than a numerical time integration. The
introduction of a novel vector field to the phase space allows the Lyapunov exponent
to be expressed in a form that does not involve time. The Lyapunov...
We used recent phenomenological form factors to calculate the effect of on-shell
two-pion exchange in nucleon-nucleon scattering below the two-pion production
threshold. As expected, the contributions of partial wave amplitudes are all negligible.
We also noticed that the relativistic spin-operator decomposition of the
scattering amplitude is not unique at certain...
We exhibit long-lived resonances in scattering from two-dimensional soft cage potentials comprised of three and four Gaussian peaks. Specific low-energy resonances with very narrow width are shown to correspond to classical multiple-reflection events. These states have much larger probability densities inside the cage than outside and mimic bound states in...
The purpose of this paper was to study the relationship of a
high school family life course to post high school problems and
marriage role expectations. The specific objective of the study was
to determine whether or not there is a relationship between participation
in a high school family life...
The purpose of this study was to investigate the relationship between
physiological maturation and the intrapersonal relations of adolescent
girls. The Interpersonal Check List provided the measure of
self concept and ideal self concept for each subject.
Subjects were 48 early-maturing and 48 late-maturing girls
representing the four levels of...
The primary purpose of this study was to replicate a study of
Abel and Sahinkaya which investigated the emergence of race and sex
preferences of upper middle socioeconomic status Caucasian
children. This study provided a good match with respect to socioeconomic
status, race, and sex; however, the number of subjects...
The purpose of this study was to investigate the relationship
between specific mother-child interactions and selected aspects of
language development in "disadvantaged" children.
The subjects were 19 preschool children in a summer Head
Start program in Denver, Colorado. Their ages ranged from four
years-nine months to five years-seven months. Eighteen...
The purpose of this study was to investigate the differences
between middle- and lower-class adolescents and the extent of their
self-disclosure to their mothers and their fathers; and their feelings
both positive and negative toward their parents and themselves.
The subjects consisted of 50 middle-class and 50 lower-class
adolescents who...
The purpose of this study was to assess change in self concept,
marital role expectation, and behavioral understanding in high
school students enrolled in a family life course.
The subjects were two groups of high school students from an
only senior high school in a school district. The experimental group...
The purpose of this study was to assess changes in attitudes
toward behavioral understanding, marital role expectations, and self
concept in a selected group of high school girls. These subjects
were enrolled in a one semester child development course which
included observation and participation experiences with young children.
The subjects...
The two major purposes of this study were: (1) to test the
assumption that the IT Scale for Children (standard-ITSC) can be used
as a measure of both appropriate sex role discrimination and sex role
preference with preschool aged children, and (2) to extend previous
studies in these areas by...
The purpose of this study was to seek information regarding
issues around which dating decisions were made and some of the steps
college freshmen women considered in deciding for or against certain
courses of action while random and steady dating. A second more
general purpose was to determine if the...
The purpose of this study was to investigate the selfconcept by
examining the relationships among self-perception, behavioral understanding,
and teacher performance. The subjects were 53 female
college students enrolled in one of three practicum classes offered by
the Family Life Department of Oregon State University. Subjects in
Group A (n=33)...
The major purpose of this study was to assess changes
in behavioral understanding and attitudes students may have
experienced in association with their participation in a
high school child development course. In addition, assessments
were made of changes in subject's perceptions cf:
1) marriage role expectation, 2) self-concept, and 3)...
The major purpose of this study was to identify those social behaviors
of children which a particular group of parents perceived as important in
the process of socialization. This purpose was in direct support of
Western Regional Research Project W-144. The study also investigated
changes in parental evaluations of children's...
A Willamette Valley farm cooperative was interested
in evaluating locations for their canning facilities based on
the criterion of minimizing aggregate distance to their contract
farms. This location problem presented an excellent opportunity
for a geographic application project as it was characterized by
one, a spatial distribution of farms and...
This dissertation details the investigation of an alternate pathway to
isoprenoids that occurs in plants and microorganisms, the non-mevalonate
pathway. This exploration of the pathway focuses on the second step, the
conversion of 1-deoxy-D-xylulose-5-phosphate (DXP) to 2-C-methylerythritol-4-phosphate (MEP) by the enzyme DXP isomeroreductase (DXR). These studies led to an appreciation...
This dissertation describes studies of isoprenoid biosynthesis in the
phytoflagellate Euglena gracilis. Elucidation of a novel isoprerioid pathway, the 2-Cmethyl-D-erythritol-4-phosphate (MEP) pathway, in addition to the generally known
mevalonate (MVA) pathway, led to extensive exploration of the distribution of both pathways in a variety of organisms. To date, photosynthetic eukaryotes...
The discovery of the methylerythritol phosphate pathway (the MEP pathway) as an alternate pathway for isoprenoid biosynthesis in some organisms including most bacteria, malarial parasites and plants, but not in animals, has stimulated extensive studies in this area. Research has revealed the potential of finding novel antibacterials, antimalarial drugs, and...
In recent years, the methyl erythritol phosphate (MEP) pathway to isoprenoids has been the subject of intensive research. The interest is because isoprenoids have important roles in many cellular processes essential for the survival of several pathogenic organisms, making the inhibition of this pathway an attractive target for the drug...
The isoprenoid pathway is one of the major biosynthetic pathways of secondary metabolites. Isoprenoids with a C₂₀ skeleton are known as diterpenoids and are derived from the common precursor, geranylgeranyl diphosphate (GGPP). This dissertation describes approaches to discover the diterpene synthase enzymes which provide the backbone structures for pleuromutilin and...
As a result of its atomic structure, carbon fiber produced from mesophase pitch
has a high electrical conductivity and high tensile strength. Others have used carbon fiber
as a resistive heating unit to accelerate matrix solidification in carbon fiber-polymer
matrix composites.
In this study, a unidirectional carbon fiber reinforced polymer...