A combination of theoretical perspectives is used to create a rich description of student reasoning when facing a highly-geometric electricity and magnetism problem in an upper-division active-engagement physics classroom at Oregon State University. Geometric reasoning as students encounter problem situations ranging from familiar to novel is described using van Zee...
The multifaceted role of the environment in regulating the structure and dynamics of biological communities has long fascinated ecologists and motivated much debate and research. Now, in a time of accelerated global changes due to human impacts, the need to understand how the environment shapes communities has gained new urgency....
Knot Theory: In Imitation of Lewis Thomas is a collection of 14, 1200-word essays written in the style of Lewis Thomas, a physician who regularly contributed to The New England Journal of Medicine. His 1200-word column, "Notes of a Biology Watcher," ran from 1971 - 1980. The resulting compilations collectively...
In the first part of this dissertation, low frequency l/f or flicker noise in the frequency range of Hz to kHz has been identified and demonstrated to be described by temperature fluctuations in heat conduction in bipolar transistors operated at higher power densities. This noise phenomenon is not described by...
The sudden failure of metal structures under load, which has
been a design problem for many years, is characterized by a crack
propagation rate which approaches the speed of sound in the material.
These failures, which are often known as catastrophic fractures,
may be divided into two types which depend...
The present study was designed to examine the relationship
between expressed attitudes toward child-rearing, and children's
social behavior in a preschool setting. More specifically, the study
was concerned with the association of parental authoritarian, hostile-rejecting,
and democratic attitudes with the aggressive and cooperative
peer interactions of preschool children. Under investigation...
A complete Gallium Arsenide Metal Semiconconductor
Field Effect Transistor (GaAs MESFET) model including deep-level
trap effects has been developed, which is far more
accurate than previous equivalent circuit models, for high-speed
applications in linear integrated circuit design.
A new self-backgating GaAs MESFET model, which can
simulate low frequency anomalies, is...
Prior to 1986, economic conditions resulted in substantial
unemployment, layoffs, and reduced work time.
Such conditions produced underemployment resulting in significant
income reductions for families. A random sample
of a non-metropolitan Northwest community elicited 137
couples from a variety of incomes. Twenty-one of them
were found to have incomes reduced...
The purpose of this paper is the statement and examination of
relevant data pertaining to the subject of trans-Pacific pre-
Columbian contact. The paper's contents will be organized in to
five major areas: oceanography, ship building, archaeology, religion
and history, plus an introduction and conclusion. Each of
these chapters will...