Western redcedar (Thuja plicata Donn.) is a valuable commercial species found in
the northwestern United States and southwestern Canada. This dissertation includes four
papers focused on wood and stem characteristics of second-growth western redcedar, and
how those characteristics vary within the stem or how they are influenced by cultural
practices....
Key message Leyland cypress, an intergeneric hybrid, produces the same volatile heartwood compounds as its parental taxa, yellow-cedar and Monterrey cypress. However, the proportion of total sesquiterpenes and some of the individual components appear unique to their respective heartwoods.
Context Leyland cypress, xHesperotropsis leylandii is an intergeneric hybrid between yellow-cedar,...
The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus), is established in coastal forests of the western United States. Since the discovery of SOD in the Douglas-fir / tanoak forests of...
The leaching of water soluble phenolic compounds from
cold stressed Rhododendron leaves was found to be a reliable
indicator of tissue damage. In sublethally stressed leaf
tissues, more and novel phenolic compounds appeared and were
hypothesized to be precursors of cell wall components such
as lignin and suberin. Subsequent radiolabeling...
In undisturbed N-limited forested catchments, DON may represent over 90% of the total N lost in streams. Some ecologists have suggested that plant-derived reactive polyphenols may be responsible for DON binding and transport because polyphenol-protein complexes are known to precipitate out of solution, bind to mineral surfaces or organic matter...
There is a continual interest in developing robust, flexible, durable, lightweight, waterborne polymer barrier coatings which are increasingly resistant towards both chemical warfare agents as well as an ever growing number of toxic industrial chemicals. In this study, barrier films were prepared with poly(vinyl alcohol) (PVOH) and varying amounts of...
This compilation of theses and dissertations (a part of the OSU Bibliographic Series) for the period 1970-1977 reflects this university's emphasis on research and graduate study. It may be viewed as an indicator of the contributions made to the state of Oregon through graduate study and research at Oregon State...
The Oregon University System, working in partnership with the Oregon Economic & Community Development Department, commissioned a bio-fuels industry readiness survey for Oregon. This report serves as one component of the readiness survey. The report has three primary sections:
• An overview of the current forest products industry in Oregon...
Many herbivores of the Pacific Northwest rely on forest understory shrub leaves for a source of nitrogen, energy, and moisture. I measured nitrogen, protein-binding capacity, and condensed tannin concentration as indicators of available nitrogen; cell wall constituents and lignin as indicators of available energy; and moisture concentration in young and...
Rubber without reinforcement has limited applications. The strength of reinforced rubber composites can be ten times stronger than that of unreinforced rubbers. Therefore, rubber composites are widely used in various applications ranging from automobile tires to seals, valves, and gaskets because of their excellent mechanical elastic properties. Silica and carbon...
This study identified new compounds with pest control activities. The two sources of candidates that were followed here were the main heartwood extract of Alaska Yellow Cedar (AYC) constituents and several semi-synthetic counterparts. Five compounds were isolated and identified for the first time in AYC heartwood in this research: two...
Agrobacterium tumefaciens is a common soil bacterium that causes crown gall
disease on many dicotyledonous plant species. It has been exploited for use in genetic
engineering because it is able to promote transfer of any DNA segment to plant
chromosomes. Many molecular factors in both the plant and bacterium contribute...
Copper migration from treated wood has created concerns within the
environmental community because of the potential effects of this heavy
metal on aquatic organisms. Migration can be limited, to some extent, by
more controlled treatments and by post-treatment processing, but these
actions cannot completely overcome the problem. An alternative approach...
Wood-plastic composites (WPCs) are one of the fastest-growing sectors of the
wood composites industry. However, the strengths of WPCs are typically low
because of the poor interfacial adhesion between hydrophilic wood and
hydrophobic thermoplastics. A compatibilizer that can form bridges between wood
and plastics is required to give WPCs desirable...
This study examined the relationship of interfacial shear strength (IFSS) and
bending strength (MOR) of several different wood-plastic composites (WPC's).
Plastics utilized were high-density polyethylene (HDPE) and polypropylene (PP).
Pine and oak were used as the wood species. Compatibilizers used included maleicanhydride
polyethylene (MAPE), polymeric methylene diphenyl diisocyanate (PMDI),
KymeneTM,...
Large numbers of vintage reinforced concrete deck-girder bridges remain in the national bridge inventory. Many of these exhibit diagonal cracking and other distress. Due to the design practices of the time, it is common to observe cracks at locations where flexural reinforcing steel is terminated along the span. The presence...
While the heartwood of many wood species exhibits excellent resistance to fungal and insect attack, this resistance is sometimes diminished in second-growth material of the same species. The reasons for the reduced durability are unclear, but they may reflect a combination of both higher proportions of sapwood as well as...
In wood-plastic composites (WPCs) a compatibilizer is often used to improve
the interfacial adhesion between the hydrophilic wood filler and the hydrophobic
plastic matrix. At present, while the basic concepts of compatibilization are
understood, the optimized chemical structures of an effective compatibilizer, including
the ideal structures of the wood-binding domain...
Focus on Forestry is published by Oregon State University's College of Forestry. Our goal is to keep Forestry alumni, friends, faculty, staff, and students informed about the College of Forestry and its many activities and programs.
Spotted knapweed, Centaurea maculosa Lam. (Compositae) is an extremely
successful introduced weed species in the northwestern United States. Multiple factors
may be responsible for its success, including chemical defense. Two different types of
putative chemical defense agents are the focus of this thesis. The first is a bitter-tasting
sesquiterpene lactone,...
Heartwood can have properties that are distinct from sapwood,
including resistance to insect and microbial attack. Despite the practical
importance of heartwood formation in trees, a review of the literature revealed
that little was known about the effects of environmental factors on heartwood
quality or how variations in heartwood properties...
Patterning of metal oxides typically involves a multi step process, involving
depositing a resist, patterning that resist with some form of lithography, etching the
oxide through the resist, and finally removing. This process can be simplified if the
resist is removed and replaced with a metal oxide that can be...
Natural fibers are gaining popularity as reinforcement materials for thermoset resins over the last two decades. Natural fibers are inexpensive, abundant, renewable and environmentally friendly. Kenaf fibers are one of the natural fibers that can potentially be used for reinforcing unsaturated polyester (UPE). As a polymer matrix, UPE enjoys a...
Synthetic adhesives, such as phenol-formaldehyde (PF) resins and urea-formaldehyde (UF) resins, have dominated the wood adhesive market since they were introduced in the wood products industry. Formaldehyde, as a key component in the manufacturing of PF and UF resins, has been classified as a known human carcinogen by the International...
Formaldehyde-based adhesives such as urea-formaldehyde (UF) and phenol-formaldehyde (PF) adhesives dominate the current wood adhesive market. However, these adhesives are derived from petrochemicals and carcinogenic formaldehyde. In this study, we developed two formaldehyde-free adhesives based on abundant, renewable, and inexpensive soy flour (SF).
The first adhesive was mainly composed of...
Microchannel devices are rapidly evolving process technology with a wide variety of applications. Microchannel devices hold the potential to transform many separation processes. One potential application for such microchannel devices is kidney dialysis. By reducing the size and cost of the device, this technology offers the potential to allow dialysis...
High density polyethylene (HDPE) is a ubiquitous material with versatile properties. It is produced and used in greater volume than any other thermoplastic. HDPE is often filled with a variety of materials for various applications. Glass fiber and wood flour are two common fillers for HDPE. Recently there has been...
The essential oil components of cedar heartwoods play an important role in the durability of these trees. Yet, the composition of these oils and identity of many of the compounds remains unknown, or incompletely know for some commercially important cedar heartwoods. The essential oil extracts of Alaska Yellow Cedar (Chamaecyparis...
This research provides details of water resource conflict and cooperation in Oregon between 1990 and 2004 by using an event database methodology. Events were concentrated in four of 18 basins. No basin accounted for more that 25% of the total water rights events, the most evenly distributed issue type. Overall...
Agroforestry is a traditional farming practice in American Samoa that has helped to sustain the livelihood of the native population for centuries. These once self-sufficient islands have become economically dependent on U.S monies and other external resources during the past century. Dependency has caused a shift in the carrying capacity...