X-ray computed tomography is a noninvasive imaging modality capable of reconstructing exact density values of 3D objects. Computed tomography machines are deployed across the world to provide doctors with an image that reveals more detail than a standard x-ray image. We investigate algorithms based on exact computed tomography reconstruction formulas...
This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on aircraft design criteria under the supervision of the Aeronautical Board. Information reviewed and reaffirmed March 1956 and 1962. Original report issued November 1946.
This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on Aircraft Design Criteria under the supervision of the Aeronautical Board. Information reviewed and reaffirmed 1962. Original report issued December 1946l
This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on aircraft design criteria under the supervision of the Aeronautical Board. Information reviewed and reaffirmed March 1946. Original report issued November 1946.
This report is one of a series issued in cooperation with Air Force-Navy-Civil Subcommittee on Aircraft Design Criteria under the supervision of the Aircraft Committee of the Munitions Board. Information reviewed and reaffirmed November 1954 and June 1959. Date of original report October 21, 1946.
This report is one of a series issued in cooperation with the Air Force-Navy-Civil Subcommittee on Aircraft Design Criteria under the supervision of the Aircraft Committee of the Munitions Board.
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 natural fall of trees in riparian areas is an important source of coarse woody debris for mountain streams, improving fish habitat and influencing stream morphology. Existing models consider the probability of coarse woody debris entering a stream channel based upon trees having a random direction of fall without consideration...
West Nile Virus (WNV), a vector-borne disease continues to be a serious threat to public health in the United States, particularly in the Southwest region. While all the states in the U.S. experienced a decreasing trend of WNV disease in 2010, the state of Arizona experienced a sharp increase from...
Forecasting of ocean waves over a short duration on the order of tens of seconds was approached with the optimization of wave energy conversion in mind. This study outlines the development of an artificial neural network model, specifically the Nonlinear Autoregressive Network with Exogenous Input (NARX), to predict a wave-by-wave...
The objective of this study is the development and
verification of an analytical solution for an unsteady
flow field partially occupied by a permeable structure.
Flow is induced by a small amplitude incident wave
train and the permeable structure may contain multilayered
anisotropic but homogeneous material. The analytical
solution developed...
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...
Water quality problems related to excessive algal
growth, high nutrient loading, and low flows have been
occurring along Oregon's Tualatin River. The Tualatin River
is 86 miles long and has a drainage basin of 711 square
miles. The drainage basin incorporates forest,
agricultural, and urban areas. Located in the Portland...
The volumetric receiver is an advanced solar central receiver
concept designed to produce high temperature air. This document
presents the results of a heat transfer and performance evaluation of
the volumetric receiver concept.
The volumetric receiver consists of an array of ceramic fins or
fibers arranged in concentric rows around...
Landscape models for elk distribution developed at Starkey Experimental Forest and Range from 1993-1995 were tested on another landscape during 2003-2005 at Sled Springs Wildlife Demonstration Area. Using location data obtained from 23 wild elk captured and fitted with GPS telemetry collars, 8 spatial resource selection function models representing 8...
Accurate measurement of forest productivity is fundamental to understand the carbon balance of forested ecosystems. Recent changes in climate highlight the importance of developing methods to measure forest productivity so that sound economic and environmental decision can be made. Efforts to measure forest productivity across the landscape using remote sensing...
Published January 1990. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
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...
The Elliott State Forest, located in the Coast Range of Oregon, is currently revising their Habitat Conservation Plan (HCP). Many of the constraints in the HCP are spatial, requiring identification of specific parcels in order to limit activity along habitat reserves, limit harvest opening size, and to coordinate activities within...
Two basic approaches to reduce computational requirements for solving
distillation problems have been studied: simplifications of the model based on
physical approximations and order reduction techniques based on numerical
approximations.
Several problems have been studied using full and reduced-order
techniques along with the following distillation models: Constant Molar
Overflow, Constant...
MIKE SHE is a fully distributed, physically-based hydrologic model that can simulate water movement over and under the Earth's surface. Evapotranspiration (ET) is one of the components of this model. MIKE SHE uses a modification of the Kristensen -Jensen (1975) method to calculate actual ET. This method is based on...
Real-time, high efficiency neutron spectroscopy has, historically, been a persistent challenge in the field of radiation detection and, for the most part, has gone unsolved. The most promising method to resolve this challenge, is the boron-capture technique using an organic scintillation system (BC-523a). Detectors that utilize this method possess an...
The report describes the results of model calibration and validation, and evaluates the extent to which runoff response to timber harvesting and increased road densities in East Fork Lobster Creek Basin can be simulated, using Precipitation-Runoff Modeling System (PRMS), a deterministic, destributed-parameter-modeling system.
This dissertation consists of three papers on land use economics and policies. The first two papers focus primarily on local land use policies and urban development. The third paper addresses the question how environmental amenities affect households' residential choices in a metropolitan area. In the first paper, an option value...
In this paper we develop an upscaling technique for non-Darcy flow in porous media. Non-Darcy model of flow applies to flow in porous media when large velocities occur. The well-posedness results for theory of quasilinear elliptic partial differential equations. To discretize the model we used lowest order Raviart-Thomas mixed finite...
Motivated by observations of locally enhanced sea level variability near steep
topographic slopes in regions of strong time-mean flows, effects of zonal ridge topography
on zonal oceanic jet flow are investigated. Unstable wave properties and the
dynamics of eddy-mean flow interaction are evaluated as a function of topographic
geometry using...
The Pacific salmon market may often be characterized by
disequilibrium conditions and less than perfect information. Thus the
study of the decision-making behavior, especially short-run pricing,
of wholesale market participants in this industry requires the use of
alternative models to the conventional, price-taking, perfect
competition model of the firm.
This...
Deep foundations are necessary for the construction of many structures, such as bridges and buildings, located in areas unsuitable for shallow foundations. Owing to the inherent variability of soil and the complex changes that occur in the soil adjacent to deep foundations as they are installed, the ability to accurately...
The Oregon State University (OSU) Advanced Plant Experiment (APEX) is a one-fourth height, one-half time scale, reduced pressure integral systems test facility designed to model the long-term cooling capabilities of the emergency core cooling systems of the Westinghouse AP600. This study provides a brief description of the APEX test facility,...
The low thermal conductivity of gallium arsenide compared to silicon
results in self-heating effects in GaAs MESFETs that limit the electrical
performance of such devices for high power applications. To date, analytical
thermal models of self heating in GaAs MESFETs are based on the assumption
of a uniformly heated channel....
Development of variable speed horizontal axis wind turbines has resulted in a need for an analysis code with a rotor speed degree-of-freedom. This study develops a five degree-of-freedom time domain computer code that evaluates blade and rotor, mean and cyclic loads with nonlinear aerodynamics together with atmospheric turbulence as a...
Recent tsunami field surveys from the 2011 Great East Japan Earthquake and Tsunami have recorded numerous examples of tsunami-induced soil instability: significant scour around foundations, foundation failure of piles, and other damage caused by liquefaction. From the observations of soil instability leading to the failure of critical coastal structures, it...
The objective of this study is to develop a mathematical model to relate the production of juvenile sockeye salmon in the Wood River
Lake system to parent stock size, primary and secondary production, population size of predators and competitors, and abiotic variables.
"We have developed graphical and logical models for explaining the production of a consumer on the basis of the capacity of an ecosystem to produce that consumer (the productivity of the system for that consumer), on the basis of the biomass of the consumer, and on the basis of the...
Volume I: TREES (Timber Resource Economic Estimation System), a forest management and harvest scheduling model, is comprehensively described in the first of a four-volume series. Even- or uneven-aged forest inventories form basic resource units (BRUs), entered by age class or size and diameter classes; stocking level; and management intensity. Management...
Simple models of transpiration, e.g., the Penman-Monteith equation, treat atmospheric conditions as driving variables. In fact, transpiration modifies temperature and humidity throughout the convective boundary layer, creating feedbacks that stabilize the water use of vegetation. This thesis concentrates on the new empirical relationships proposed by Monteith (1995), for developing simple...
We assessed use and selection of cover by coastal cutthroat trout (Oncorhynchus clarkii
clarkii) in six headwater streams in three watersheds in western Oregon, USA during the summer low flow period from 1 August and September 30, 2007. We tagged 1037 coastal cutthroat trout (>100 mm) with passive integrated transponder...
This report is one of a series issued in cooperation with the ANC-23 panel on sandwich construction of the departments of the Air Force, Navy, and Commerce. Information reviewed and reaffirmed 1960. Original report issued April 1955.
Energy use and greenhouse gas emissions are on the forefront of planning policy in the world today. In the U.S., the transportation sector accounts for 50 percent of greenhouse gas (GHG) emissions, the most of any single sector. State and local levels of government have been very proactive in the...
Mass transfer processes were evaluated in an artificial, non-uniform porous medium with a power law distribution of diffusion rate coefficients obtained from physical characterization of solute and porous medium. Breakthrough curves of several pulse experiments conducted at different velocities were compared (1) to analytical expressions for concentrations at mass transfer...
An analytical model is developed to address the question of how different disturbance
regimes affect the mean and variance of landscape carbon storage in forest ecosystems. Total landscape carbon is divided into five pools based on the processes from which they are derived and based on their temporal dynamics. Formulae...
Knowledge of wave conditions in nearshore regions supports the development of
ocean wave energy technology by providing wave climatology for device design
considerations, and power output estimates. By modeling wave transformation
over the continental shelf, wave conditions were predicted in nearshore regions
where potential wave energy conversion sites are located....
The accurate determination of cloud cover amount is important for characterizing the role of cloud feedbacks in the climate system. Clouds have a large influence on the climate system through their effect on the earth's radiation budget. As indicated by the NASA Earth Radiation Budget Experiment (ERBE), the change in...
This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on aircraft design criteria under the supervision of the Aeronautical Board. Information reviewed and reaffirmed March 1956 and 1962. Original report issued January 1948.
This report is one of a series issued in cooperation with the ANC-23 panel on composite construction for flight vehicles of the departments of the Air Force, Navy, and Commerce.
This report is one of a series issued in cooperation with the ANC-23 panel on composite construction for flight vehicles of the departments of the Air Force, Navy, and Commerce. Original report issued 1959. Information reviewed and reaffirmed 1965.
A numerical technique to compute the time domain response of multiconductor lossy
uniform and nonuniform lines terminated in general nonlinear elements is presented. The
technique is based on the generalized method of characteristics. The method transforms the
original system of transmission line equations into a system of ordinary differential
equations....
Current trends in integrated circuit technology are continuing towards physically smaller components and related structures. Interconnects between circuit components have reached sub-micron dimensions which can not be modeled accurately by the current ideal microstrip analysis based techniques. These techniques often assume that the structure being modeled is perfectly conducting, smooth,...
The classical two-dimensional wavemaker problem is formulated for
linear waves. Two conformal mappings are applied to the mathematical
formulation to transform the wavemaker problem into a unit disk. It is then
shown that this technique cannot produce in practice a numerical
representation of the fluid motion throughout time for any...
Although some of the most difficult problems in forest management occur as a result of timber harvest operations, present methodology in harvest planning emphasizes guidelines which rely heavily upon the experience of the individual forest manager for their correct application. This study was undertaken in an effort to develop a...
Tide-topography coupling is important for understanding surface-tide energy loss, the intermittency of internal tides, and the cascade of internal-tide energy from large to small scales. Although tide-topography coupling has been observed and modeled for 50 years, the identification of surface and internal tides over arbitrary topography has not been standardized....
This research examines the downstream fining phenomenon as it operates in coastal gravel-bed rivers of Oregon. Downstream fining is a change in bed composition toward smaller sediment sizes in the downstream direction. Changes in stream flow discharge and channel slope affect the rate of bed-load transport, thereby altering the downstream...
Recent advances in wireless technologies have helped the proliferation of wireless devices, ranging from hand-held devices such as cellular phones to more powerful mobile computing platforms as such laptops [1]. Along with that, the end users’
applications running on these devices, ranging from text message to multimedia applications such as...
Polymeric composites exhibit time-dependent behavior, which raises a concern
about their long term durability and leads to a viscoelastic study of these materials.
Linear viscoelastic analysis has been found to be inadequate because many polymers
exhibit nonlinear viscoelastic behavior. Classical laminate theory is commonly used in
the study of laminated...
Brushless Doubly Fed Machines (BDFM) have potential advantages in variable
speed generation and adjustable speed drive applications. The most significant of these
advantages is a reduction in the power electronic converter rating, and therefore a
reduction in overall system cost. Presently, efforts are being directed at optimizing the
design of...
An understanding of natural coastal hazards is essential for improving resilience of coastal communities. Effective management of coastal hazards relies on prediction tools and mitigation structures that have been designed to handle the dynamic coastal system. This dissertation is a collection of manuscripts that cover a diverse range of fundamental...
These three papers address uncertainty in the management and valuation of renewable natural resources. The first paper develops a model to integrate both stock and price uncertainty to obtain optimal resource levels. The model is an extension of Reed (1974) and shows by proof and by example that when prices...
Coarse resolution imagery, such as that produced by the MODIS instrument, poses the challenge of estimating sub-pixel proportions of di erent land cover types. This problem is di cult because of the variety and variability of vegetation within individual pixels. This thesis describes and compares two existing algorithms for estimating...
The study is based on a frame of reference for comparing characteristics
of ordered pairs of members of small groups ("relators" in relation to "co-relatives"). An attempt is made to replicate selected
findings from a study of the acquaintance process reported by
Theodore Newcomb. The effectiveness of three measures of...
A new second order accurate nonuniform grid spacing technique which does not
depend on supraconvergence is developed for Finite Difference Time Domain (FDTD)
simulation of general three dimensional structures. The technique is useful for FDTD
simulations of systems which require finer details in small regions of the simulation space by...
Contract harvest operations have become the preferred approach to reducing the largest cost component of timber production through free market competition amongst logging contractors bidding or negotiating for work. The goal of this research was to investigate economic components of harvesting operations not previously studied for steep slope thinning harvests...
Non-dilute salt strength solutions occur in many near surface geologic environments. In order to better understand the occurrence and movement of the water and salt, mathematical models for this non-ideal fluid need to be developed. Initial boundary value problems may then be solved to predict behavior for comparison with observations....
Using thermodynamic principles, the general relationship describing the equilibrium vapor content in the gas phase above a saline liquid and across a curved liquid-gas interface is developed. Since high salt concentration also affects the intensive and extensive liquid properties, it is also necessary to account for these effects in liquid...
The thermal contact conductance (TCC) between two machined pieces of stainless steel was studied. A guarded hot plate thermal conductivity test fixture was designed and built for the experiment. Factors investigated included the contact pressure, surface roughness, interface material and average test temperature. The contact pressure at the interface ranged...
In order to properly model the temperature distribution of a nuclear fuel pin, the thermal conductivity
of the fuel must be known. For sphere pac fuel, the
modeling of the conductivity is complicated due to the
fact that the fuel is a collection of spheres in a random packed bed....
Development of micro air vehicles has led to a strong interest in the biomechanics of flapping fliers such as bats, birds, and insects, due to their ability to perform extreme unsteady maneuvers and fly in confined spaces. Determining the methods and mechanisms used by these fliers is a valuable source...
This thesis explores the vibrational behavior of the main components of sound production in the violin using a continuum mechanics approach. The author provides a mathematical description of the regions in the vibrating continuum, and begins to develop a system of equations governing their behavior, focusing on the air in...
Quantitative habitat models of wildlife-habitat relationships are developed to
formalize our current understanding about an ecological system. A habitat
association model is one of these models that is useful for answering questions
about how the habitat is occupied, how much growth habitat is required by the
animal, or how the...
A time dependent model of the shallow, tropical convective boundary layer is
developed and tested. To simplify the treatment of thermodynamic processes and
return to first principles of physics, conserved quantities of entropy and total
water density are used as primary model variables. In addition, a new shallow
cumulus parameterization...
The experimental and theoretical bases of transient electric birefringence (TEB) and its application in a variety of nanomaterials, including Na-montmorillonite, cellulose nanocrystals (CNXL), and CdSe quantum dots (QDs) will be presented. TEB is a phenomenon attributed to the alignment of particles in response to an applied electric field and has...
The time-averaged velocity field in the North Pacific was estimated in two
sets of inverse calculations. The planetary geostrophic equations were the basis for
dynamical models of the flow in each case. The inverse estimates of the circulation
were obtained by minimizing a positive-definite cost function, which measured the
inconsistency...
Under certain conditions, a neural network may be trained to perform a
specific task by altering the weights of only a portion of the synapses.
Specifically, it has been noted that certain three layer feed-forward networks may
be trained to certain tasks by adjusting only the synapses to the output...
This dissertation presents a research series demonstrating the use of pharmacokinetic modeling and simulations as tools to assess drug concentration and disposition in patient populations. For drugs requiring therapeutic drug monitoring, these tools are necessary to ensure patients are receiving a safe and effective dose of medication to address their...
The Earth Radiation Budget Experiment (ERBE) uses Angular Dependence Models
(ADMs) to convert satellite observed radiances to radiative fluxes at the top of the
atmosphere. Owing to errors in scene identification and to the relationship between
the spatial scales of cloud systems and the spatial resolution of the ERBE scanner,...
A finite difference scheme is employed to solve the
integral form of the momentum, continuity and heat
equations, for a two layer ocean bounded by a coastline.
The momentum equations include the turbulent dynamics and
the time-dependent and nonlinear terms in both the
cross-shelf and alongshelf directions. The system of...
The study presents two main parts: first, a review
of tropical silviculture and forest management systems
and, second, the investigation of a growth and yield
model which has some potential for application in the
tropical region. The presentation of tropical
silviculture includes: (1) an overview of the biological
characteristics of...
The atmospheric fluidized bed combustor (AFBC) is an alternative to
the pulverized coal burner. The size of a utility scale AFBC would be
enormous so that the use of large particles is necessary to reduce its
size. In modeling the combustion of coal and capture of sulfur released
from the...
The two dimensional wavemaker problem on a finite domain is derived
for nonlinear waves. A numerical method based on the method of lines is
developed and applied to two test problems, the nonlinear surface pressure
distribution problem and the nonlinear full-flap wavemaker problem. The
solutions yield information about the fluid...
This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on Aircraft Design Criteria under the supervision of the Aeronautical Board. Information reviewed and reaffirmed 1956.
A long running problem in mathematical biology is the prediction of extinction events, a specialized case of the larger global stability problem found in differential equations and dynamical systems theory. A central technical question is how to introduce the randomness observed in real ecological systems not accounted for in deterministic...
For over 30 years, the Implicit Monte Carlo (IMC) method has been used to
solve challenging problems in thermal radiative transfer. These problems are typically optically thick and di ffusive, as a consequence of the high degree of "pseudo-scattering" introduced to model the absorption and reemission of photons from a...
The statistics describing variations of turbulent motions within the so called inertial range of length scales depend on the scale over which the motions are varying and the "average" rate at which the turbulent kinetic energy is being dissipated on the molecular scale. This hypothesis stemmed from the similarity arguments...
Variability in wood properties causes boards within a stack of lumber to
dry at different rates and reach different moisture content levels after drying is
completed. The consequence is that the boards will have properties that differ from
ones that were intended to be achieved by the drying process.
The...