In the past decade considerable research in several disciplines has been oriented toward the design of optimal capacity expansion plans for water resource systems. The emphasis of most of these efforts has been directed toward minimization total cost outlays in project planning. This focus somewhat limits the full applicability of the optimal capacity expansion solutions since it is believed that the criteria of economic efficiency is not well addressed in this mode. This study explores the merits of scheduling water resource project facilities on the basis of anticipated economic benefits provided, an approach needed only infrequently in the systems engineering literature. Using the Umatilla River Basin in Northeast Oregon as a case study example, the facilities (and their alternatives) of a previously planned federal water resource development project in that area were carefully analyzed with respect to the magnitude and timing of anticipated benefits and costs. Irrigated agriculture and fishery development/enhancement benefits were the two principal purposes of the project considered. In addition, benefits arising from flood prevention, municipal and industrial water supply, and erosion control were also integral to the original overall evaluation. The design of the research was to first implement a basic scheduling model in the context of the case study area and then to explore the ramifications of exchange-theoretic and distribution-theoretic criteria on the timing of facilities and the ultimate allocation of water among purposes. The model implemented was aimed at maximizing the present value of net benefits inherent in an optimally timed set of facilities subject to an annual budget constraint. Having designed the model along integer programming lines, three different solution techniques were explored in order to realize a desirable level of efficiency in basic model solution. It was found that reasonably efficient solutions could be obtained. By optimally timing the facilities it was found that the total present value of net benefits of the project could be significantly enhanced when compared to the original schedule proposed in the project planning documents. Of even greater interest is the issue of incorporating into the planning process (and specifically into the capacity expansion mode of planning) considerations of tradeoffs or exchanges between project beneficiaries. Such exchanges and other distributional criteria can affect and be affected by the selection and timing of project facilities within an overall project design. These interrelationships are explored paying particular attention to the way in which exchanges of water (via water rights transfers) could establish higher levels of benefits in future years. Noneconomic exchange processes such as the enforcement of extant property rights relating to water resources are another issue which complicated the process of water planning. Such distributional criteria are difficult to incorporate into the capacity expansion mode of planning analysis. However, ways are explored by which the basic model may be modified and used by decision makers in order to take account of more realistic problems in water resource planning for individual river basins. / Graduation date: 1981 / Partially funded by the U.S. Dept. of the Interior as authorized under the Water Research and Development Act of 1978. / Final technical completion report for project no. A-046-ORE to U.S. Dept. of the Interior.

Graduation date: 1953

This study was directed to improve our understanding of the ecology of Swiss needle cast (SNC) of Douglas-fir, a disease that produces extensive damage to forests and plantation in the coastal region of Oregon and Washington. A disease prediction model for the coastal area of Oregon was built by establishing the relationship between the distribution of disease severity and the environment. Currently available methods of determining the distribution of SNC were analyzed, and the possibility of mapping the disease using Landsat TM satellite images was explored. Two types of regression approaches were used to study the relationship between disease severity and climate, topography, soil and forest stand characteristics. Although both types provided useful information and insight, the multiple regression approach was chosen over the regression tree analysis to build the model, due to its capacity to produce a continuous prediction response. Fog occurrence, precipitation, temperature, elevation and slope aspect, were the variables that contributed to explain most of the disease severity variability. Findings agree with and formalize our previous understanding of the ecology of SNC: cool and wet conditions in summer appear to increase disease severity. When the model was applied to past climate conditions, retrospective predictions suggest that changes in climate in the last two decades could help to explain the observed recent regional increase in SNC disease severity. The resulting model was used to construct a disease prediction map. This map showed an accuracy equivalent to the currently available SNC aerial survey. The prediction model, however, is able to produce a continuous prediction surface, more suitable for testing and appropriate for assisting in disease management and research. A strong relationship between mature stand canopy defoliation and the Landsat TM indices greenness and brightness, indicates that it is possible to use satellite imagery to map SNC. In contrast, young stands showed high variability, most likely due to the relatively high proportion of exposed understory vegetation. The possibility of mapping stand defoliation is of great importance because this symptom can be directly linked to tree growth and forest productivity. Satellite imagery can be used in future and in retrospective disease mapping. / Graduation date: 2002

Jackson County, Oregon is noted for the production of high quality pears. It is the fourth leading pear producing county in the United States and is the number one producer of winter pears. This thesis analyzes in detail the many aspects of the pear industry in the county. Climate, soils, topography, and progressive growers have been the main localizing factors. The study revealed that 200 growers produce the average annual total of three million boxes of pears on 9940 acres of bearing orchards. The pears are prepared for market in 12 packing houses and two canneries. The industry has a direct impact on the county of $15,000,000. The problems confronting the industry are caused by physical and biological factors. Spring frosts and hail damage are problems imposed by the climate. Pear Blight, Pear Decline, and Pear Scab are the main diseases. Insect pests such as the Pear Psylla and the Codling Moth must also be combatted. Urban encroachment has not yet been a serious problem in the county. The future for the industry appears to be stable, with little change in acreage. The fruit gift box industry will become of increasing importance, thus creating further emphasis on producing winter pears. / Graduation date: 1963

Driving simulation is widely accepted as a safe, effective, and economical alternative for investigating driver behavior in a variety of contexts. However, in order to apply simulator-based research results to real-world settings, the performance measures acquired through simulated driving experiments must first be validated. This research was aimed at validating the Oregon State University Driving Simulator based on speed, acceleration, and deceleration data. The validation effort consisted of a road test and a simulator test. The road test was completed on a five-lane urban principal arterial in Corvallis, Oregon, and the simulated environment matched the field conditions as closely as possible. Ten subjects participated in both tests. Minimum speed, maximum speed, average speed, 85th-percentile speed, maximum acceleration and maximum deceleration data variables were analyzed using graphical comparisons as well as two-sample paired t-tests. With the exception of minimum speed, all data variables showed statistically significant differences on at least one of the three test sections. However, the researchers considered the magnitude of these differences to be insignificant in a practical setting (on average, 3.5 mph for speed variables and 0.80 ft/s�� for acceleration and deceleration variables). Thus, the results of this research confirm the validity of the OSU driving simulator with regards to speed and acceleration. / Graduation date: 2013

Ranching and lumbering were two of the primary economic practices in a small rural study area south of Philomath Oregon (in Benton County), from first Euro-American settlement through 1930. Ranching was common but lumbering was restricted by geographical and market transportation problems until after 1900. Catalysts for change came in the form of individuals and advanced technology. The introduction of trucks marked a cusp between two eras for both loggers and cowboys. Two important historical facts were discovered through oral history-gathering, regarding this rural area: first, the story of the first successful lumber company to build a mill close to Philomath, and second, the occurrence of a remarkably popular Round-Up in this small town, in 1916. The two primary oral informants were both born at a rural mill settlement established by this lumber company, at the foot of the Coast Range, in the southwest part of the study area. Junctions (and distinctions) between geography and economy, city and country, loggers and ranchers, and oral and written history are highlighted in specific detail. Because of long geographical isolation from big lumber markets, this region's timberlands, mills, loggers and lumber companies remained in the hands of local people, into the 1950s. This area thus underwent a history quite different from coastal logging history. Attention to local oral sources and specific catalysts for change in other such small rural regions would broaden current historical understanding of the history of the West, and the Pacific Northwest. / Graduation date: 1999

The objective of this study was to characterize an unknown agent associated with decline in black raspberry (Rubus occidentalis) in Oregon. A virus was found consistently associated with decline symptoms of black raspberries and was named Black raspberry decline associated virus (BRDaV). Double stranded RNA extraction from BRDaV-infected black raspberry revealed the presence of two bands of approximately 8.5 and 7 kilobase pairs, which were cloned and sequenced. The complete nucleotide sequences of RNA 1 and RNA 2 are 7581 nt and 6364 nt, respectively, excluding the 3' poly(A) tails. The genome structure was identical to that of Strawberry mottle virus (SMoV), with the putative polyproteins being less than 50% identical to that of SMoV and other related sequenced viruses. The final 189 amino acids of the RNA-dependent- RNA-polymerase (RdRp) reveal an unusual indel with homology to AlkB-like protein domains, suggesting a role in repair of alkylation damage. This is the first report of a virus outside the Flexiviridae and ampeloviruses of the Closteroviridae to contain these domains. An RT-PCR test was designed for the detection of BRDaV from Rubus tissue. BRDaV is vectored non-persistently by the large raspberry aphid Amphorophora agathonica, the green peach aphid Myzus persicae, and likely nonspecifically by other aphid species. Phylogenetic analysis of conserved motifs of the RdRp, helicase, and protease regions indicate that BRDaV belongs to the Sadwavirus genus. To assess the rate of spread BRDaV, four newly planted fields of black raspberries (Rubus occidentalis) in Oregon were studied for three years. In an effort to characterize the suspected complexity of synergistic interactions between BRDaV and other Rubus-infecting viruses, the prevalence of ten additional Rubus viruses was also monitored in the study fields. The timing of BRDaV infection as it relates to aphid populations and flights was also determined. Testing of nearby vegetation identified several symptomless Rubus hosts of BRDaV, as well as detection in multiple cultivars of black raspberry and several non-Rubus weeds. It was determined that BRDaV spreads rapidly with a low aphid threshold and consistently is associated with decline of black raspberries in Oregon. / Graduation date: 2006

More and more, modern society is incorporating the use of radioactive materials into everyday uses. And with society using more radioactive materials, the odds of it being accidentally disposed of into the solid waste stream increases. There are several radiation systems available which market themselves as being complete and "ready to go". While it is true that a person could purchase one of these systems and would have coverage of the landfill, such a system does not provide the necessary education, response and liability protection programs. Indeed, it would be feasible to foresee a scenario where installing a systems could lead to an increase in liability and employee problems. As a result, Coffin Butte Landfill worked with the author to establish a complete radiation monitoring program. This program encompasses everything from installment of the system to employee education and training. It also examined the myriad and murky depths of federal and state regulation dealing with solid and radioactive waste to help the landfill set an acceptance policy and minimize liability. This led the author to the belief that the combination of federal and state regulations imply a requirement for landfills to have a working radiation monitoring program. Future government action remains uncertain as pertaining to a requirement for landfills to maintain a radiation monitoring system. Indeed, current state regulations are out of sync with federal regulations regarding acceptable public exposures. It is hoped that, with this study's help, Coffin Butte Landfill and Oregon State University will continue with the established relationship and be prepared to respond to regulation changes. / Graduation date: 1999

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 mycelial growth of B. cinerea and P. expansum in nutrient yeast dextrose agar (pH 4.5 or 7.0) incubated for 8 or 30 days at 24 or 1 C, respectively. These three yeasts also were evaluated for their ability to suppress spore germination of B. cinerea and P. expansum in a gradient of apple juice concentrations and to suppress development of gray and blue mold lesions in inoculated fruits of Golden Delicious apple. Germination of B. cinerea and P. expansum was reduced significantly (P���0.05) when incubated with the yeast isolates in 100 or 50% apple juice, but not in 0, 1 or 10% apple juice. S. roseus and A. pullulans reduced significantly (P���0.05) the size of gray mold lesions in wounded fruit stored at 5 C and 24 C by 63 to 72 and 81 to 90%, respectively, when compared to the nontreated control. Size of blue mold lesions in fruit stored at 5 and 24 C also were reduced significantly (P���0.05) by 66 to 38 and 74 to 63%, respectively, when pre-treated with S. roseus and A. pullulans. In general, fruit rot suppression by some yeasts isolated in this study was similar in magnitude to suppression obtained by Cryptococcus laurentii isolate 87-108, a yeast with commercial potential to suppress postharvest rots of pome fruits. Pretreatment of apple wounds with washed cells of A. pullulans, S. roseus, Rhodotorula sp., resulted in disease suppression, but treatment of wounds with cell-free culture supernatant of these isolates did not affect lesion development. Population size of A. pullulans, S. roseus, and C. laurentii increased in apple wounds incubated at 5 or 24 C for up to 25 days, indicating that they colonized the wound site. Data collected in this study support the hypothesis that yeast isolates antagonize fruit pathogens by competing for nutrients in wounds on fruit surfaces. The isolates of A. pullulans and S. roseus show promise for commercial development. / Graduation date: 1997

Graduation date: 1997