The main objective of this thesis was to determine the influence of tree vigor on susceptibility to Armillaria root disease. First, the effect of thinning, fertilizing
and pruning on tree vigor of four young Douglas-fir (Pseudo tsuga menziesii var.
menziesi,) plantations was explored. Tree vigor was calculated by measuring wood...
The main focus of this work is on the problem of existence of nonlinear optimal controllers
realizable by artificial neural networks. Theoretical justification, currently
available for control applications of neural networks, is rather limited. For example,
it is unclear which neural architectures are capable of performing which control
This research was conducted as part of the Strategic Highway Research Program (SHRP)
A-003A contract at Oregon State University to validate the findings of SHRP contracts
A-002A and A-003B with regard to aging of asphalt-aggregate mixtures. One short-term
and four long-term aging methods were used to simulate aging of asphalt-aggregate...
Nisin is an antibacterial peptide, which when adsorbed
on a surface can inhibit bacterial adhesion and viability.
The ability of noncovalently immobilized nisin to withstand
exchange by the milk proteins bovine serum albumin, β-lactoglobulin, α-lactalbumin, and β-casein on surfaces that
had been silanized with dichlorodiethylsilane to exhibit
high and low...
Diode lasers have many advantages such as small size, high efficiency and small
angular dispersion of the collimated beam. However they also have some problems like
lack of frequency stability. They can not be tuned in wavelength. An external cavity can
solve these problems and decrease the laser linewidth.
The objectives of this research were to 1) evaluate the establishment and peak
standing crop of Berber Orchardgrass (Dactylis glomerata var. "Berber"), Palestine
Orchardgrass (Dactylis glomerata var. "Palestine"), and Sheep Fescue (Festuca ovina
var. "Covar") ; 2) to assess establishment and production changes resulting from
environmental gradients (elevation, slope, aspect,...
Alias periods and wavelengths for the M2, S2, N2, K1, O1, and P1 tidal constituents are calculated for TOPEX/POSEIDON. Alias wavelengths calculated in previous studies are shown to be in error, and a correct method is presented. With the exception of the K1 constituent, all of these tidal aliases for...
The wind speed and significant wave height (H1/3) dependencies of the sea state is in altimeter estimates of sea level, expressed in the form ∆hSSB=bH1/3, are examined from least squares analysis of 21 cycles of collinear TOPEX data. The bias coefficient b is found to increase in magnitude with increasing...
Altimetric data from the TOPEX/POSEIDON mission will be used for studies of global ocean circulation and marine geophysics. However, it is first necessary to remove the ocean tides, which are aliased in the raw data. The tides are constrained by two distinct types of information: the hydrodynamic equations which the...
In 1987, Congress authorized a 5 year $150 million dollar research program called
the Strategic Highway Research Program (SHRP). SHRP was divided into four major
areas, including the asphalt research program. The asphalt research program was divided
into six major research contracts, one such contract, SHRP-003A was called Performance
The incipient motion of sediment particles in gravel-bed
rivers is a very important process. It represents the
difference between bed stability and bed mobility. A field
study was conducted in Oak Creek, Oregon to investigate
incipient motion of individual particles in gravel-bed
streams. Investigation was also made of the incipient...
A new method for encapsulating low-molecular weight, water-soluble substances
in lipid-walled microcapsules (LWMs) for delivery to marine bivalves was developed,
characterized, and tested. LWMs produced by a spray technique (spray microcapsules,
SMs) were demonstrated to encapsulate both aqueous (polymeric dye or oxytetracycline
hydrochloride) and particulate (riboflavin) core materials within a...
Forest recreation is one of the many non-commodity functions of forests that have
experienced a rapid growth in demand in the past few decades. Even faster growth in
demand for recreation is expected for several decades. However, such growing demand
for forest recreation is often not well perceived by owners...
The island of Tahiti, the largest in French Polynesia, comprises two major volcanoes aligned NW-SE, parallel with the general trend of the Society Islands hotspot track. Rocks form this volcanic system are basalts transitional to tholeiites, alkali basalts, basanites, picrites, and evolved lavas. Through K-Ar radiometric dating we have established...
This thesis presents the design of various controllers for a highly maneuverable, high performance aircraft, namely the modified F-18. The aircraft was required to perform high angle-of-attack maneuvers, for which the aircraft behaves in as a highly nonlinear system. An adaptive PID controller was used to control the aircraft through...