As microelectronic parts trend smaller so do their solder joints. The surface finish on a copper pad is expected to become a significant part of the total solder joint volume and therefore affect mechanical properties of the smaller solder joints. Two sample geometries and four different surface finishes for tin-silver-copper...
The purpose of this study was to address the implementation fidelity of one part of a professional development model developed by the Northwest Regional Educational Laboratory (NWREL). Specifically, this research investigates middle school teachers’ use of a formative feedback guide developed by NWREL staff, examining the reliability with which teachers...
The lentil strain of pea seedborne mosaic virus, PSbMV-L, was
distinguished from the standard isolates of PSbMV by a natural inoculum
reservoir in lentil seed and by separate resistance genes in Pisum
and Lens. PSbMV-L was intermediate in symptom severity between the
standard and New Zealand isolates of PSbMV.
Seed...
An experiment was conducted to evaluate the influence of forest fuels reduction on diet quality, botanical composition, relative preference, and foraging efficiency of beef cattle grazing at different stocking rates. A split plot factorial design was used, with whole plots (3 ha) being fuel reduced or no treatment (control), and...
Hybrids with abnormal development were obtained when particular
genotypes of Phaseolus vulgaris L. were crossed. The phenotypic
aberrations of the F₁s included retarded growth, chlorosis of the
trifoliate leaves and the formation of adventitious roots on the
hypocotyls. The expression of the abnormalities was dependent on the
temperature. At high...
The purpose of this article is to explore student reasoning with regard to problems in logic, particularly those related to the Principle of Mathematical Induction (PMI). The five case studies presented build off of work done by other researchers, most notably Dubinsky and Harel, who both looked at how students'...
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Thomas P. Dick
The purpose of this article is to explore student reasoning with regard to
Responses of biological indicators of soil quality to winter cover cropping were measured on soil samples collected from 6 commercial growers' fields and two experiment research stations in the Willamette Valley of Oregon. The research stations were the North Willamette Research and Extension Center (Aurora, OR), and the Oregon State...
The purpose of this study was to investigate teaching models that may aid in
improving student's understanding of how to interpret graphs of kinematic variables.
The teaching models that were considered incorporated the use of cooperative groups
and calculator-based laboratory instruments, alone and in concert. The subjects used in
this...
Humboldt County has several areas which have naturally
high to extreme wildland fire hazards. Recent settlement within
these areas increases the likelihood of a destructive fire. This
report examines the extent and degree to which climate, slope and
vegetation influence the wildland fire hazard in Humboldt County,
as well as...
An extensive literature survey investigated methods and approaches
for evaluating intangible economic factors at the strategic
and tactical levels of managerial decision making. These sources
provided: 1) the background for a theoretical decision making
algorithm developed for comparing alternative economic proposals
for effectiveness at the strategy levels, and 2) a...
The response of sweet corn (Zea mays L. var. rugosa cultivar
Jubilee) to 12 populations and four nitrogen rates was studied in a
field experiment. Populations ranged from 43, 904 to 329,800
plants/ha with nitrogen levels ranging from 0 to 224 Kg/ha. A systematic
spacing design was used. Plant height,...
The rapid decline of marine ecosystems worldwide and the failure of traditional single species management pushed for the development of ecosystem-based conservation measures such as marine protected areas (MPA) to slow the loss of marine biodiversity. One approach to MPA creation advocates targeting marine megafauna (e.g., marine mammals, seabirds, sharks,...
Contamination of recreational and shellfish waters with fecal pollution is a major water quality issue with associated economic impacts and human health risks. Reliable fecal source identification and rapid, quantitative analyses are essential components of risk assessment. Enteric bacteria that are endemic to specific hosts have a potential role as...
Zinc Sulfide (ZnS) thin film, with a wide band gap, has been used for many applications, such as buffer layer for CIGS solar cells, light emitting diodes and thin film electroluminescent devices.
In this work, ZnS thin films were prepared using two different deposition processes. In the first method, ZnS...
Two summertime days were investigated, 27 and 28 June 1973,
to observe the changes in the environment that led to the severe hailstorm
on 28 June in the National Hail Research Experiment (NHRE)
network, Colorado. Within the network thermodynamic analyses
revealed the 28th to have:
(1) Above-average low-level moisture.
(2)...
Common root rot is a major disease of commercially grown snap bean (Phaseolus vulgaris L.) on the irrigated sandy soils of central Wisconsin. The objective of this study was to determine the relationships between soil properties and suppressiveness to common root rot of snap bean (causal agent Aphanomyces euteiches) in...
Forest harvest can have significant impacts on forest ecosystems that may influence the capacity of soils to sequester carbon (C). The microbial community controls decomposition, which is a critical process in partitioning litter- and root-C between CO₂ and storage in semi-permanent soil-C pools. The objectives of this study were to...
Herbivory by domestic and wild ungulates can dramatically affect vegetation structure, composition and dynamics in nearly every terrestrial ecosystem of the world. These effects are of particular concern in forests of western North America, where intensive herbivory by native and domestic ungulates has the potential to substantially reduce or eliminate...
Fava bean is used as a winter or spring cover crop, green manure, silage, forage, hay, and vegetable. It is capable of producing large amounts of dry matter and accumulating large quantities of nitrogen (N), part of which is available to subsequent crops.
Nitrogen availability in agricultural soils from fertilizer, plant residue inputs, and soil organic matter has important implications beyond crop yield. Legume winter cover crops and one fourth the recommended N rate on sweet corn resulted in yields equivalent to those at the recommended rate in the Willamette Valley of western...
Soil response and function were investigated following the adoption of an integrated reduced-tillage and cover-cropped vegetable system in the Willamette Valley of Western Oregon. The experiment was conducted over three cropping seasons (2002-2004) at the Oregon State University Vegetable Research Farm (Corvallis, OR). The design was a randomized complete-block with...
Piliostigma reticulatum and Guiera senegalensis are two native shrubs that
coexist with row crops in parkland systems of the Sahel of Africa. Although
permanently green all year around in soil depleted in nutrients and dry for a nine-month
period, these shrubs have been largely overlooked. Conventional management of these
shrubs...
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Richard P. Dick
Piliostigma reticulatum and Guiera senegalensis are two native shrubs that
The Oregon Long-Term Soil Quality Project was initiated to identify soil
properties that respond rapidly to alternative management practices. Such practices
included winter cover cropping, which was implemented at two experimental research
stations and several grower fields throughout the Willamette Valley. The goal of this
thesis was to identify the...
Two native shrub species (Piliostigma reticulatum and Guiera senegalensis) are prominent vegetation components in farmers’ fields in Senegal. However, their role in nutrient cycling and ecosystem function has largely been overlooked. A study including both laboratory and field experiments was conducted to evaluate potential biophysical interactions of the two shrub...
A 2-year field study was conducted on the effects of two sulfur
fertilizers (calcium sulfate or elemental S, 0 or 50 kg S ha⁻¹ yr⁻¹)
on the distribution of sulfur fractions (inorganic sulfate, C-bonded,
ester sulfate, and residual S), arylsulfatase enzyme activity, and
microbial biomass carbon (C) and sulfur (S)...
A variety of soil properties have been proposed and tested as potential
indicators of soil quality. This study was conducted in an effort to produce a
standardized soil quality index for systems in Oregon. Soils in both forested and
agricultural systems were sampled in a wide variety of locations, climates,...
A method based on fatty acid (FA) analysis is used to profile microbial community structure (MCS). Various extraction protocols are available, which alter the types of FAs extracted from soils. The more time consuming but widely used protocol extracts only FAs from phospholipids (PLFA). This technique is desirable because PLFAs...
Increasing regulation and costs of soil fumigation to manage diseases such as
Verticillium wilt caused by soil-borne pathogens have prompted a search for
management alternatives. Single-year microplot experiments were conducted in 2002
and 2003 in central Oregon to evaluate the effects of Austrian winter pea, broccoli,
and Sudan grass green...
Teachers may be attracted to the use of a game in a learning activity under the presumption that students will find the game experience to be more “fun” than typical classroom activities. The use of a game in a learning activity should help students attain important learning outcomes and engage...
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Thomas P. Dick
Teachers may be attracted to the use of a game in a learning activity
Speckled dace (Rhinichthys osculus) is a small cyprinid that is geographically widespread throughout western North America, and the most frequently occurring sh in Oregon. Because of the genetic and morphological variation in this species across its range, it has been referred to as a "species complex" and no revision to...
Common vetch is a viny, succulent, annual legume attaining a height of 24 inches when planted alone. It grows taller when planted with a tall companion crop that provides structural support for climbing.
Crimson clover may be used as a cover crop, green manure, pasture, or hay. It often is used as a winter annual cover crop in annual rotations. It has been used successfully in reduced-tillage farming systems, and in orchards and vineyards where it can be managed to reseed itself.
Field pea can be used as a cover crop, green manure, forage, hay, and silage. Hay is good quality, but pea is more succulent than vetches and more difficult to cure. Regrowth after mowing or grazing is poor.
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...
While the role of ubiquitin in protein degradation is well established, the role of other ubiquitin-like proteins (UBLs) in protein degradation is less clear. Neural precursor cell expressed developmentally down-regulated protein 8 (NEDD8) is the UBL with the highest level of amino acid identity when compared to ubiquitin. Here we...
As the drive continues to reduce the size of Printed Wiring Assemblies (PWAs),
improve performance of electronic assemblies, and reduce costs of these products,
reliable secondary (bottom) side reflow operations must be developed. Attaching Surface
Mount Technology (SMT) components to the secondary side of a Printed Circuit Board
(PCB) is...
Cereal rye is an erect annual grass with greenish blue, flat blades and an extensive fibrous root system. It resembles wheat, but usually is taller (3–5 ft) and tillers less. Flowering is induced by 14 hours of light in spring.