A new approach to oversampled delta-sigma A/D converters ( AZ modulators ) is introduced, where a differential pseudo-Npath filter stage is used as a basic cell. In this band-pass application, the z to -zN transformation is employed to realize a RAM-type pseudo-2-path lossless integrator. The bandpass second-order and 4th-order delta-sigma...
Continuous process scale-down and emerging markets for low-power/low-voltage mobile systems call for low-voltage analog integrated circuits. Switched-capacitor (SC) circuits are the building blocks for analog signal processing and will encounter severe overdrive problems when operating at low voltage conditions. There exist three techniques to solve the problem, but with their...
Digital systems, in particular microprocessor, have recently experienced phenomena growth in performance. Both technology advancement and clever design have sustained this performance growth. As clock frequency heads into the Ghz range, new circuit design, for both logic and storage, are needed. Such new circuit technology must provide needed performance with...
Oversampling analog-to-digital and digital-to-analog converters are gaining more
popularity in many signal processing applications. Delta-sigma modulators are used in practical applications of oversampling systems because of their apparent practical advantage over other oversampling converters in terms of insensitivity to the inevitable imperfection of the analog circuitry.
In Δ∑ modulators, analog...
Studies are currently underway to determine the suitability of Yucca Mountain
in Nevada as the nation's first high-level nuclear waste repository. Values of net
infiltration are required to determine pre-waste emplacement groundwater travel times
and the performance of the repository as a waste containment system. The objective of
this study...
Frankia from root nodules of nine different species of Ceanothus were
characterized. DNA was amplified directly from nodular material using the polymerase
chain reaction (PCR). The amplified region includes the 3' end of the 16S rRNA gene,
the intergenic spacer (IGS), and a large portion of the 23S rRNA gene....
Many high-elevation stands of noble fir in the northern Oregon Cascades are being
actively managed. Forest managers are investigating different activities that will control
stand impacts and the subsequent spread of Heterobasidion annosum a rot pathogen on
the Warm Springs Indian Reservation. The purpose of this study was to quantify...
The remodeling of the central nervous system (CNS) during metamorphosis in Drosophila melanogaster is a prime model system in which to study the genetic control of the sexual dimorphisms in the abdominal ganglion of the CNS. I have been using a P[tau-lacZ] enhancer trap line, 4.078, to label a segmentally...
Recent in vitro data provide evidence that estrogen may assist in the maintenance of
nervous tissue viability. Anecdotal reports suggest a lower prevalence of SDAT in
postmenopausal women who have received estrogen replacement therapy although
published data are conflicting. The purposes of this study are to determine whether the
incidence...
The effects of deforestation and biomass burning in tropical dry forests (TDF) remain a little studied phenomenon. We quantified total aboveground biomass (TAGB), carbon and nutrient (N,S,Ca,P,K) loss under two separate fire severity scenarios; one early when the fuels were higher in moisture content, one later when the slash fuels...
Oversampled analog-to-digital (A/D) converter architectures have been receiving
increased attention for high-precision A/D converters. These architectures offer the
means of exchanging resolution in time for that in amplitude. Among these
oversampled A/D converters, delta-sigma modulators are the most popular method
used due to their simplicity in the analog circuitry. The...
Increased competition brought about by trade liberalization has raised the stakes
for improving productivity in U.S. and Canadian food processing. A key element of
productivity growth is technological change, which in turn results from R&D investment.
The present study employs an econometric model to assess rates of technological change
and...
Biaxial strength characteristics of wood-based structural panels were evaluated by
using analytical and experimental methods. Cruciform plywood specimens were tested
under biaxial tensile-tensile, compressive-compressive loadings in a symmetrically-jointed-
arm test fixture, which was mounted on a universal testing machine. Performance
of the test fixture was also evaluated during the tests....
The Salt Range is clearly the active participant in the scenario of the progressive southward migration of the Himalayan thrust front. It extends approximately 180 km ENE along strike and is underlain by salt. This is manifested by its very narrow (<1°) cross-sectional taper and great (150 km) width. Integration...
In this study the enzymatic activity of adsorbed Thermomonospora fusca E₅ and Trichoderma reesei CBHI cellulases were investigated using fluorescence techniques. In particular, cellulases were allowed to contact hydrophobic polystyrene surfaces under conditions of different solution concentrations, and adsorption times. Each of these variables is known to have a potential...
Fire exclusion in the western U.S.A. has caused fuel loads to build up and overall forest health to decline. Managers are now looking for ways to reduce these fuel loads while reintroducing some of the desired effects of natural wildfire. One method to do this is thinning using mechanical harvesting...
Efficient use of water in agricultural production involves accurate assessment
and control of the quantity and spatial uniformity of excess percolation. Passive
Capillary Samplers (PCAPS), which sample water from the vadose zone have shown
potential to provide superior estimates of soil water flux compared to alternative
methods. In a four-year...
Watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai var.
Crimson Sweet) was seeded in a commercial peat mix in multicell
containers (72 cells-tray⁻¹, 40 cm³-cell⁻¹) in July 1989 and April 1990.
In 1989, the medium was amended with CaC0₃ at 10% w:v. In 1990, no
CaC0₃ amendment was made. Watermelon seedling...
Many ecological systems follow a seasonal cycle affecting primary production,carbon flux, and vegetative gas emissions. The seasonal variation of ecological systems are both affected by and have effects upon climatic factors. A quantitative estimate of the seasonal variation of vegetation is required to characterize ecological systems and their interaction with...
The Gandghar Range and Kherimar Hills, located in the Hill Ranges of northern
Pakistan, contain rocks that are transitional between unmetarnorphosed foreland-basin
strata to the south and high-grade metamorphic and plutonic rocks to the north. The
southern Gandghar Range is composed of a succession of marine strata of probable
Proterozoic...
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...
Although the occurrence of ketosis is a postpartum phenomenon, recent studies have
focused on the prepartum period as key in the development of the disorder. Indicators of
prepartum energy status, such as depressed dry matter intake (DMI) and elevated plasma
non-esterified fatty acid (NEFA) concentrations have been associated with the...
Eight phylloplane yeasts were isolated from backyard apple trees in Corvallis, OR. Yeast isolates were classified to genus or species level. All isolates were tested in vitro for antagonistic activity against the postharvest pathogens Botrytis cinerea and Penicillium expansum. Of these isolates, Aureobasidium pullulans, Sporobolomyces roseus Rhodotorula sp., consistently reduced...
Alcoholic off-flavor and accompanying volatile compounds produced by bananas (Cavendishii spp) held at 20°C and subjected to aerobic (air control treatment) or anaerobic conditions (nitrogen treatment) were compared by solid phase micro extraction (SPME), a newly developed method for volatile separation. In general, volatile production was suppressed under anaerobic conditions...
The herbicide, Dacthal (dimethyl 2,3,5,6,-tetrachloroterephthalate) is
hydrolyzed to give the corresponding diacid and this derivative is a common
contaminant in ground water. In the Ontario region of eastern Oregon the
use of this herbicide on onions has resulted in the contamination of an
aquifer with this derivative. Since movement to...
The average size and age of chinook salmon (Oncorhynchus
tshawytscha) caught in commercial fisheries along the Pacific Coast
of North America have decreased substantially in this century. These
declines might be caused in part by changes in size and age at
maturity within the stocks contributing to those fisheries. Upriver...
This study outlines a procedure to review and identify the current forest management situation and techniques employed on
the Alsea District of the Siuslaw National Forest (SNF) in
Western Oregon and compare them to the situation and techniques
employed on the Bimbo-Lobaye Forest District (BLFD) in the
Central African Republic...
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...
Potato ground cover and spectral data were measured
in the Columbia Basin during the 1990 growing season.
Three spectral were correlated with ground cover;
normalized difference, near infrared-red ratio, and the
first derivative of the spectral curve at 750 nm. All
models were statistically significant at the 99% level.
Normalized...
Until recently, occurrence of milk fever (MF) has been attributed to prepartum calcium intake. However, researchers in Iowa have concluded that high prepartum dietary potassium (K) is the major cause of MF. Potassium concentrations have been increasing on manure fertilized soils over the last 20 years. Grasses grown on these...
This research has focussed upon both the in vitro and in vivo characterization
of the recycling pathway leading from 5'-deoxy-5'-methylthioadenosine
to methionine in fruit. In addition to contributing towards polyamine
biosynthesis and other important cellular functions, in plant tissues
these events also serve to generate the hormone ethylene. A broad...
Estimations of plant water use can provide great assistance to growers, irrigators,
engineers and water resource planners. This is especially true concerning the introduction
of a new crop into irrigated agriculture. Growing hybrid poplar trees for wood chip stock
and veneer production under agronomic practices is currently being explored as...
The National Park Service initiated a backcountry campsite restoration project
in 1987 to restore native vegetation on severely degraded campsites in three subalpine
lake basins in Yosemite National Park. Restoration treatments included soil
scarification, transplanting, manual seeding and site protection. Eight of the treated
campsites were monitored in 1990 to...
Knowledge of a compound's degradation pathway is crucial to the assessment of risk at contaminated sites. Pentachlorophenol and its metabolic products can serve as model compounds to study the fate and transport of halogenated aromatic compounds in the environment. Acclimation of anaerobic sewage sludge to pentachlorophenol produced a microbial consortium...
Rapamycin (5) was isolated in 1975 from the soil bacteria Streptomyces hygroscopicus and its structure was determined from spectroscopic techniques and an x-ray crystallographic analysis. Although it was initially found to exhibit antibiotic activity, it was subsequently shown to possess potent immunosuppressive activity as well.
Three approaches to the synthesis...
Recent declines in nesting success of some fish-eating seabirds in Alaska have been attributed to declines in availability of certain schooling forage fishes (e.g., capelin Mallotus villosus, Pacific sand lance Ammodytes hexapterus, and Pacific herring Clupea harengus pallasi). These fishes tend to have high lipid content compared with other species...
A novel acyl protecting group for cytosine and adenine has been prepared
from 4-( chloromethyl) benzoic acid. Reaction of the acid with morpholine produces
4-( 4-morpholinyl )methyl benzoic acid which is converted to it's acid chloride
with thionyl chloride. This may be used to acylate cytidine and adenosine under
standard...
Groundwater resources have become seriously threatened
due to improper use by industrial, municipal, and even public
sectors. Widespread contamination of aquifer systems has
jeopardized human health and the environment and methods for
restoring these systems are needed. Biological and chemical
in situ remediation, where contaminants are degraded within
the natural...
The experiment was conducted to compare multiple pest (weed, soil arthropod and diseases) suppression by cereal cover crops in 'Selva' and 'Totem' strawberry. In addition, perlite was used to compare improvement of soil and root aeration which might modify strawberry black root rot complex. Small-seeded summer annual weeds were suppressed...
Potato (Solanum tuberosum L.) is one of the most productive and nutritious food crops. Due to its adaptability to cool climates, production in Sri Lanka has been restricted to erosion-prone highlands. Vast potential exists for expansion of potato cultivation in the lowlands while production areas in the highlands are limited...
A practical and versatile instrument has been developed both to
optimize the chemistry of bio- and chemiluminescence reactions and to
measure ultra-trace quantities of associated analytes. The instrument
consists of a pneumatic flow injection system linked to a detection cell and a
signal processing and readout system. The disk-like cell...
This study defines the information gathering and communication and response
needed for safety at highway-rail crossings. It examines technologies for low-cost,
high-safety treatments for low volume highway crossings of higher speed (130-200 kph) rail. Crossing closure and consolidation is a necessary first step. Existing
train control and crossing safety systems...
Steel corrosion in reinforced concrete is a major concern to transportation agencies nationwide because of the expenses incurred for repair and ultimate shortening of bridge life. Cathodic protection (CP), as a remedy, has been applied to reinforced bridges in the US since 1974. However, application of this technique is largely...
Two related techniques, based upon ion-exchange solid phase extraction, have been
developed for the determination of arsenic speciation. The inorganic arsenic species
arsenite (As(III)) and arsenate (As(V)) are separated by anion-exchange and detected with
graphite furnace atomic absorption spectrophotometry (GFAAS) with a nickel matrix
modifier. The first separation technique, which...
A low pressure halide transport chemical vapor deposition (HTCVD) system to grow ZnS:Mn electroluminescent phosphors is characterized. Reactor parameters such as gas composition, gas flow rate, and source and substrate temperature are investigated. Crystal structure is investigated using x-ray diffraction, electron spin resonance, and transmission electron microscopy. Chemical characterization includes...
Effects of amount of applied water and frequency of irrigation
on head rot and yield of three broccoli cultivars were evaluated in
1987 and 1988. Two irrigation frequencies were established with a
line-source sprinkler system for 5.5 weeks during heading. The low-frequency
experiment was watered once per week and the...
Growing trees as a green manure crop together with an annual food crop is a new technology for farmers in Oregon. To promote farmer participation and to acquire a broad knowledge of the processes involved in species interactions, three feasible alley cropping and two sweet corn monocrop planting patterns were...
To assess the impact of low-altitude jet overflights on parental care, we examined nest attendance, time-activity budgets, and provisioning rates of 21 Peregrine Falcon (Falco peregrinus) pairs breeding along the Tanana River, Alaska in 1995 and 1996. Several intrinsic and extrinsic factors influenced attributes of nesting behavior. Female nest attendance...
A gas phase kinetic model for the CF₄/O₂ microwave discharge plasma and afterglow of our laboratory has been developed. A reaction pathway identifying the major chemical reactions is proposed. The rate coefficients of the electron impact dissociation reactions are determined at three different plasma powers using both published electron molecule...
Three experiments whose objectives were to investigate cover
crop kill by winter freeze, weed suppression by 'Micah' barley and
other spring cereals, and allelopathic potential of cereal covers
were conducted at the Vegetable Research Farm and in the greenhouse
and growth chamber facilities at OSU in 1989/90. Kill by winter...
Concern regarding increased coastal erosion has heightened amid growing acceptance of global warming and associated sea-level rise. This study examines shoreline erosion in Flathead Lake, Montana due to five decades of artificially elevated lake levels. It provides a model to investigate coastal erosion associated with sea-level rise. The natural water...
Estimates of average annual precipitation (AAP) are-needed for hydrologic modeling at
Yucca Mtn., Nevada, site of a proposed, high-level nuclear waste repository. Historical
precipitation data and station elevation were obtained for stations in southern Nevada and
southeastern California. Elevations for 1,531 additional locations were obtained from
topographic maps. The sample...
I conducted acoustic lure surveys of northern pygmy-owls (Glaucidium gnoma) on transects that were systematically placed in forested areas throughout the state of Oregon. My objectives were to determine if pygmy-owls were associated with particular forest types, ecoregions, or with large-diameter dominant overstory trees. I also examined temporal variation in...
Site preparation treatments are often used prior to the planting of clearcut
forest lands to improve planter access and to increase the number and quality of
planting spots. Most mechanical site preparation treatments alter the
configuration and material composition of surface soil materials, and can have
marked effects on soil...
The adoption process is an information seeking and
information-processing activity (Rogers, 1983,p. 21).
Fashion information which consumers receive from various
sources directly affects their decision to adopt or reject a
style (Sproles, 1979, p. 173). Research has shown that
consumers vary in their use of fashion information sources
during the...
More efficient methods are needed for the in-situ evaluation of mass transfer parameters which describe the movement of solutes through aquifer material. The objective of this study was to develop a method for estimating diffusion rate and capacity coefficients using a single-well, "push-pull" tracer test. The method consists of the...
Process development of halide transport chemical vapor deposited (HTCVD) ZnS:Mn thin film has been studied. To this end, electrical characterization of HTCVD ZnS:Mn electroluminescent devices has been used. Process optimization focused on a simple design of experiment (DOE) with brightness as the major response. Deposition parameters such as HCl and...
Educational institutions are exposed to a continuously changing environment. As in business, they experiment with their methods and techniques to improve their outputs. Performance assessment, both in education and business is a gray science. It is not just a question of evaluating performance. Performance is comprised of a number of...
Physical appearance is one of the most important cues
that an individual uses in forming an impression of another
person. Researchers have found that perceptions of age are
negatively related to perceptions of physical attractiveness.
Because salespeople are influential in affecting a store's
sales, especially for nondurable goods (Undell, 1972),...
Cultural practices in snap bean production were evaluated at the Oregon State University Vegetable Research Farm Corvallis, Oregon. In addition, decision-making in snap bean production was assessed on five farms in the Coburg-Junction City-Harrisburg regions of the Willamette Valley, Oregon. A field experiment with cover crop and tillage techniques was...
In order to examine the potential impact of military jet overflights and other disturbances on productivity of peregrine falcons (Falco peregrinus), we observed behavioral reactions of peregrines to disturbances at nests along the Tanana River, Alaska during the 1995-1997 breeding seasons. Military jets conducted low-altitude flights over a sample of...
Succinic acid, a low molecular weight dicarboxylic acid was used to leach out
heavy metals from Willamette Valley soil (contaminated separately with lead, copper,
and zinc) in form of water-soluble organo-metal complexes. The research tasks included
developing synthetic contaminated soils representative of those found at Superfund sites
and making heavy...
Aphids are a widespread family of plant pests, whose abilities to suppress shoot
and root growth are well documented for many terrestrial plants. Only a few studies have
been conducted on conifer aphids of the genus Cinara. Cinara pseudotsugae are known
to attack Douglas-fir seedlings, an important crop in the...
Understanding the processes involved in the transport of dissolved gas plumes in groundwater aquifers is essential for comprehending the effect that these transport processes can have on site characterization and remedial design applications. Previous laboratory and field studies have indicated that dissolved gas transport in groundwater can be greatly affected...
Meadowfoam (Limnanthes R. Br. spp.), a source of C₂₀
and C₂₂ fatty acids, is a new industrial oilseed crop
adapted to the Willamette Valley of Oregon. Increased oil
yield per land area may increase the rate of meadowfoam
commercialization. Using two half-sib L. floccosa x L.
alba lines, 85-765 and...
Cereal residues suppress the development of small seeded, summer annual weeds. The focus of this study was to determine whether cereal residues can be used to suppress weeds in cucumber production systems in the Pacific Northwest. In the first of three experiments, cereal residues of fall-planted, spring-killed cover crops suppressed...
Multi-level decision feedback equalization (MDFE) is an effective technique to remove inter-symbol interference (ISI) from disk readback signals, which uses the simple architecture of decision feedback equalization. Parallelism which doubles the symbol rate can be realized by setting the first tap of the feedback filter to zero.
A mixed-signal implementation...
Decision feedback equalizer (DFE) is an effective method to remove inter-symbol
interference (ISI) from a disk-drive read channel. Analog IC implementations of DFE
potentially offers higher speed, smaller die area, and lower power consumption when
compared to their digital counterparts.
Most of the available DFE equalizers were realized by using...
Five boron rates and seven water levels were applied
to bush green beans (Phaseolus vulqaris cv Oregon 91G) and
to cauliflower (Brassica olereacea var. botrytis, cultivar
"Snowball Y") in 1989 and 1990 to evaluate their effects on
total yield of both crops and on outer quality, head
hollowness and internal...
Doppler-free saturation spectroscopy in an optically thick atomic vapor is used in an
optical-feedback configuration for two semiconductor diode laser systems. One laser
system consists of an unmodifed, commercially available diode laser. The other laser
system consists of a diode laser initially stabilized by optical feedback from a diffraction
grating....
Ellipsometry was used to study the effects of surface energetics
and temperature on the equilibrium adsorptive behavior exhibited by
β-lactoglobulin. β-Lactoglobulin isotherms at 25, 37, and 55°C were
constructed for this purpose. The surfaces of acrylic, polycarbonate,
polyester, glass, and #304 stainless steel were contacted with protein
solutions of varying...
This research focuses on the anaerobic transformation of trichloroethylene (TCE) that is occurring in the subsurface of the Evanite site in Corvallis, OR. Two anaerobic studies were conducted to investigate the effects of microbial communities in the presence of different electron donors during the anaerobic degradation of trichlorofluoroethylene (TCFE), and...
The effect of pH and ionic strength on the equilibrium adsorptive
behavior of β-lactoglobulin onto hydrophobic and hydrophilic
silicon surfaces was studied using ellipsometry. Plots of amount
adsorbed (μg protein/cm²) as a function of protein concentration
(mg/ml) exhibited attainment of plateau values beyond a protein
concentration of 0.250 mg/ml. At...