Intertemporal timber supply models typically assume perfect capital markets and perfectly inelastic supplies of land. Using a dynamic model of U.S. timber and agriculture markets, we examine (i) borrowing limits or capital constraints, in which investment in forest management on nonindustrial private ownerships is restricted, and (ii) a nonzero elasticity...
We have used the modal expansion of the wave function in the discontinuity region based on the superposition principle together with a mode-matching technique to investigate the transmission characteristics of semiconductor quantum wire structures with discontinuities. Our calculations compare quite well with published results for the theoretical transmission coefficient and...
Narrow channel devices were fabricated using a split-gate high electron mobility transistor structure in which electrons are forced through a double-bend discontinuity. The low-temperature conductance shows a number of peaks in the lowest quantized conductance plateau which correspond qualitatively to resonance effects that are predicted for the geometrical discontinuities of...
Plantago ovata Forssk. (Plantaginaceae) is a species that, in North America, inhabits desert and Mediterranean habitats of the southwest United States, northwest Mexico, and the Channel Islands of California and Mexico. In the Eastern Hemisphere, P. ovata inhabits desert regions ranging from the Canary Islands, across northern Africa to India....
Mapped cpDNA restriction site characters were analyzed cladistically and the resulting phylogenetic hypotheses were used to test monophyly and relationships of the infrageneric classification of Lathyrus (Fabaceae) proposed by Kupicha (1983, Notes from the Royal Botanic Garden Edinburgh 41: 209–244). The validity of previously proposed classification systems and questions presented...
We present benthic isotope stratigraphies for Sites 1236, 1237, 1239, and 1241 that span the late Miocene–Pliocene time interval from 6 to 2.4 Ma. Orbitally tuned timescales were generated for Sites 1237 and 1241 by correlating the high-frequency variations in gamma ray attenuation density, percent sand of the carbonate fraction,...
The pentacyclic tritcrpene 17β(H), 21β(H)-hop-22(29)-ene (diploptence) occurs in sediments throughout the Columbia River drainage basin and off the southern coast of Washington state in concentrations comparable to long-chain plantwax n-alkanes. The same relationship is evident for diploptene and long-chain n-alkanes in soils from the Willamette Valley. Microorganisms indigenous to soils...
Detailed upper ocean profiles of 234Th in dissolved (< 10,000 Daltons), colloidal (10,000 Da–O.45 μm), and particulate (>0.45 μm) forms were measured at a station (46º45′N, 126ºW) in the northeast Pacific Ocean. On average, dissolved, colloidal, and particulate 234Th accounted for ~78, 12, and 10% of the total 234Th in...
Within the altered parts of the glass rim of pillow lavas of Hole 896A, at depths at least 432 m below seafloor (237 m below the top of volcanic basement), microbes have been identified. This is indicated by the size and shapes of alteration textures and verified by the presence...
The majority of the Earth's shallow crust is composed of basalt that erupted on the seafloor and was subsequently altered by chemical exchange with seawater. One aspect of this alteration is the replacement of glass by secondary minerals, including clays. Petrographic thin sections from ODP Holes 504B and 896A revealed...
Ocean Drilling Program Hole 896A (1°13.01'N, 83°43.39'W) is
in 3440 m of water east of the Galapagos Platform in the equatorial
eastern Pacific Ocean. At this site in 5.9 Ma crust, basement rocks
were recovered over the depth range of 195.1 meters below seafloor
(mbsf) to 469 mbsf. These rocks...
The impact of population abundance on the deposit-
feeding rate of Mediomastus ambisetu (Capitellidae:
Polychaeta) was studied in still-water laboratory experiments.
Mean individual pellet production rate (mg worm¯¹ d¯¹) decreased
monotonically with increasing worm abundance in the
range of 6.5 X 10³ to 1.3 X 10⁵ worms m¯². Worms fed...
During Ocean Drilling Program Leg 204, 80 in situ measurements of
subseafloor temperature were made; 68 of these showed good frictional
pulses on insertion and extraction from the seafloor and were used to
constrain the subsurface temperature. Considering uncertainties from
various sources, uncertainties in the in situ temperatures are estimated...
Three successful vertical seismic profiles (VSPs) were acquired during
Ocean Drilling Program (ODP) Leg 204 at South Hydrate Ridge. The
data confirm earlier results from ocean bottom seismometer data and
analysis of moveout from common midpoint reflection data that the
average velocity between the seafloor and the bottom-simulating reflector
(BSR)...
Ocean Drilling Program (ODP) Leg 204 to Hydrate Ridge, located on the continental slope offshore Oregon (USA), was the first drilling expedition dedicated to understanding gas hydrate processes in accretionary complexes and provided a testbed for a number of different techniques for estimating the gas hydrate content of sediments. It...
The potential for particle size-dependent bioturbation rates was experimentally tested at 1,240 m in the Santa Catalina Basin (eastern Pacific). Spherical glass bead tracers in five size classes (8- 16, 17-31, 32-62, 63-125, and 126-420 μm) were spread over the sediment surface and tube cored 997 d later. Downcore concentrations...
The efficiency of six disaggregative methods and two individual-tree methods was evaluated in terms of their ability to predict 5-year basal area increment for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in western Oregon. Models were developed for predicting gross stand basal-area increment and individual-tree diameter increment. In addition, models were...
Canopy architectures of five structurally complex forest stands and three structurally simple forest stands in southwest Oregon and the Willamette Valley, Oregon, were evaluated and quantified through crown area profiles. Mixed conifer and mixed conifer-hardwood stands across a range of sites were sampled for crown widths and heights. Crown width...
Substrate respiration, mineralizable nitrogen, and nitrogen fixation rates, substrate moisture content, and temperature were measured in trenched and undisturbed plots within two western Oregon Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands. The stands represent two different environments and ages. Woods Creek, the site of the lower elevation mature 70-year-old stand, is...
Nitrogen incorporation from red alder (Alnus rubra Bong.) into an Oregon upland mesic forest soil was studied by tracing the fate of 15N added as 15N-labeled alder leaf litter. The recovery of 15N in vegetation, litter, light- and heavy-fractions of the soil, the chloroform-labile (microbial biomass) pool, and the whole...
Seedlings of Pseudotsuga menziesii (Mirb.) Franco and Betula papyrifera Marsh. were grown in the greenhouse in monoculture and dual culture in soils collected from a young mixed species plantation in the southern interior of British Columbia. The objectives of the study were (i) to evaluate the ability of P. menziesii...
Many species of Populus, particularly cottonwoods of sections Aigeiros and Tacamahaca, remain recalcitrant to genetic transformation. We demonstrate that transgenic trees can be readily produced in several poplar genotypes using wild-type Agrobacterium rhizogenes. Hairy roots were produced in a variety of clones that included Populus trichocarpa Torr. & A. Gray,...
The effects of prescribed underburning on soil total C pools, total and inorganic N pools, and in situ net N mineralization were examined during a 1-year study in ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) sites that had been experimentally burned 4 months, 5 years, or 12...
Mortality from Armillaria root rot is a major concern of forest management. Field experiments were conducted in Minnesota to evaluate interspecific differential susceptibility and to assess whether density or species composition, specifically the proportion of conifers in a plot, influences seedling mortality from Armillaria spp. Seedlings of 10 tree species...
Pollen contamination was investigated in one block (block 4) of a 10-block Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed orchard complex in western Oregon. Blocks (25 clones each) represent different breeding zones; thus, contaminant pollen sources not only included the adjacent natural stand of Douglas-fir, but also other blocks within the...
When grown together in plantations, fast-growing southern and coastal sources of loblolly pine (Pinus taeda L.)often have lower wood specific gravity than northern and inland sources. This study investigated whether this phenomenon could be explained by a later transition to latewood, associated with a longer period of height growth, of...
Contributions of sites, rootstocks, and scion clones (and the nteractions between these factors) to scion growth and reproduction were studied in loblolly pine (Pinus taeda L.). Twenty-five full-sib families were used as rootstocks. Six scion clones were grafted on them in all combinations. Study sites were three seed orchards in...
Stratified seeds of coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) were germinated, sown in soil, and seed coats and megagametophytes were removed at various stages of early seedling development. Yield and quality of DNA extracted from the megagametophytes were related to several morphological traits of the seedlings after
2...
We carried out a detailed rock magnetic and paleomagnetic study of deep-sea sediments from selected intervals of Site 1233 in order to assess whether they contain reproducible evidence for submillennial-scale environmental, climatic, and geomagnetic field variability. Three 1.5-m sediment intervals from oxygen isotope Stages 1, 2, and 3 were sampled...
Genetic variation in spring cold hardiness of shoots prior to bud break was studied in two Oregon breeding populations of Pseudotsuga menziesii var. menziesii (Mirb.) Franco, one on the west slope of the Cascade Mountains and the other in the Coast Range. In March and April 1993, and April 1994,...
The data presented in this report demonstrate significant improvements
in the ability to constrain trace element and Sr isotopic
concentrations in sediments overlying ridge-flank hydrothermal
systems. Improved sampling methods orchestrated by the Integrated
Ocean Drilling Program (i.e., advanced piston coring and
anoxic sample processing) enabled the collection of reactive pore...
Results of ⁴⁰Ar–³⁹Ar Ar dating constrain the age of the submerged volcanic succession, part of the seaward-dip ping reflector sequence of the Southeast Greenland volcanic rifted margin, recovered during Leg 163. At the 3°Ne 6 drilling transect, the fully normally magnetized volcanic units at Holes 989B (Unit 1) and 990A...
⁴⁰Ar-³⁹Ar incremental heating experiments were performed on volcanic rocks recovered by drilling during Ocean Drilling Program Leg 152, southeast Greenland Margin (63°N), and Deep Sea Drilling Project Leg 81, southwest Rockall Plateau (56°N). Both of these legs drilled into thick sections of submerged lava flows, known as seaward-dipping reflector sequences,...
A new laboratory technique to simulate the initiation of wood decay and to assess the effects of incipient decay on material properties is described. Douglas-fir heartwood specimens were exposed to brown-rot (Postia placenta and Gloeophyllum trabeum) fungi for various periods. Bendlng properties were determined by nondestructive and destructive tests, and...
The effect of pretreatment of Douglas-fir flakes with CCA-C, borate, and azaconazole on properties of flakeboard was studied. Flakes had higher retention levels of CCA-C and borate in their ends than in their centers. The distribution of chemicals was uniform in panels, which indicates that the chemicals did not migrate...
The effects of moisture content, flow direction, concentration, and temperature on the diffusion of chloropicrin in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) heartwood were investigated. Diffusion coefficients were strongly affected by wood moisture content. Coefficients for radial and tangential diffusion at the fiber-saturation point were twice as high as those at...
p-type conducting films of α- BaCu₂S₂ have been deposited onto glass and KBr substrates, yielding a conductivity of 17 S/cm and a Hall mobility of 3.5 cm²/Vs. For a 430-nm-thick film, the optical transparency approaches 90% in the visible portion of the spectrum at 650 nm, and a transparency of...
InP/SiO₂ interfaces have been studied by high resolution electron microscopy in cross section, by ellipsometry, and by x-ray photoelectron spectroscopy. The roughness of the interface is shown to vary from 10 to 100 Å peak to peak depending on the InP surface treatment prior to SiO₂ desposition, and some evidence...
Vacuum ultraviolet reflectivity measurements of three thin-film electroluminescent phosphors, zinc sulfide (ZnS), strontium sulfide (SrS), and strontium-calcium thiogallate (Sr₀.₄₅Ca₀.₅₅Ga₂S₄), are reported using thin-film samples. Measured ZnS reflectivity peak positions are in agreement with values previously reported in the literature. SrS room temperature reflectivity measurements are found to be consistent with...
Highly transparent ZnO-based thin-film transistors (TFTs) are fabricated with optical transmission (including substrate) of ~75% in the visible portion of the electromagnetic spectrum. Current–voltage measurements indicate n-channel, enhancement-mode TFT operation with excellent drain current saturation and a drain current on-to-off ratio of ~10⁷. Threshold voltages and channel mobilities of devices...
Heartwood from coastal redwood [Sequoia sempervirens (D. Don.) Endl.] is very durable and is often used untreated in harsh environments, such as cooling towers of power or chemical processing plants. Wood in this environment is often attacked by soft rot fungi. Some wood users attempt to bolster protection by including...
Supercritical fluids can markedly enhance preservative treatment of wood, but the high pressures employed can lead to collapse. We investigated the effects of the rates of pressure application and release on displacement of white spruce lumber during supercritical impregnation with carbon dioxide. Displacement was greatest when pressure was rapidly increased...
High concentrations of the fumigant methylisothiocyanate (MITC) will effectively control decay fungi in large wood structures, but the fungitoxicity of low MITC concentrations and the influence of wood moisture content (MC) on its performance are not well understood. The MC of Douglas-fir heartwood greatly influenced the susceptibility of the decay...
Vapam(r) (NaMDC) is the fumigant most commonly used to arrest and control decay of utility poles. While volatile fungitoxins are detectable only 1 to 2 years after treatment, poles treated with Vapam(r) remain free of decay fungi for 6 to 17 years. Vapam(r) decomposes to produce volatile fungicides as well...
Tests were conducted to determine the effect of ACZA composition on fixation and the roles of adsorption and precipitation in fixation. The sites of copper and zinc adsorption within the treated wood and the bonding environment of adsorbed copper were also examined. The results generally support the finding that arsenic...
The development of pressure inside wood during preservative impregnation was studied using Douglas-fir heartwood and ponderosa pine sapwood. Pressure sensors mounted on sample holders provided the most reliable measurements. As expected, pressure equilibrated most rapidly with air as the treatment medium and ponderosa pine as the test species. Pressure changes...
Alder represents an abundant but underutilized resource that has little natural resistance to decay. Treated alder might be used for stakes, posts, or other nonstructural applications. The performance of alder treated with chromated copper arsenate (CCA), copper 8 quinolinolate, zinc naphthenate (ZN), or thiocyanomethylthiobenzothiazole (TCMTB) was assessed in soil block...
The relationship between moisture content and the presence of methylisothiocyanate (MITC) in wood following various applications of sodium n-methyldithiocarbamate (NaMDC) was investigated with small Douglas-fir heartwood blocks. While MITC levels were initially higher in wetter blocks, MITC levels in drier blocks remained more stable over the 8-week test period. The...
The ability of white and brown rot fungi to colonize wood-plastic composites was investigated by measuring weight loss and anatomical changes. Three composite materials were evaluated. The material containing a 70/30 wood-high density polyethylene (HDPE) mixture was most susceptible to fungal attack, while two different 50/50 wood-HDPE composites experienced little...
Studies of the effects of various chemicals on fungal growth are difficult to perform on filamentous fungi because of the difficulty of observing the protoplasm through the rigid hyphal wall, and because most activity occurs in the region near the hyphal tip. However, hyphae can be exposed to certain enzymes...
Differences in stain susceptibility were evaluated on sterile and unsterile samples of freshly sawn, frozen and thawed, or oven-dried and rewetted ponderosa pine sapwood. Samples treated with sterile medium or with medium inoculated with either Pseudomonas putida or Bacillus subtilis were inoculated with selected wood-staining fungi. In general, fresh unsterile...
The capacitance-voltage (C-V) technique is proposed as a method for characterization of the electrical properties of alternating-current thin-film electroluminescent (ACTFEL) display devices. Analysis of the C-V and aging characteristics of ZnS:Mn ACTFEL devices indicates that the C-V technique is complementary to the charge-voltage technique in the extraction of device physics...
Electroluminesence (EL) thermal quenching refers a reduction in luminance, concomitant with a reduction in transferred charge, when an alternating-current thin-film electroluminescent (ACTFEL) device is operated at an elevated temperature. EL thermal quenching is found to be significant in SrS:Cu ACTFEL devices operated above ~60-80 °C. Maximum transferred charge-maximum applied voltage...
White electroluminescence (EL) was observed for the first time from diamond-like carbon (DLC) films at room temperature. ac voltages in excess of 200 V were applied to a metal-insulator-semiconductor (i.e., DLC)-insulator-metal device structure to observe EL. At an applied voltage of 235 V, the brightness and efficiency were 0.5 fl...
Hot electron luminescence experiments are performed on ZnS alternating-current thin-film electroluminescent (ACTFEL) devices in order to determine the extent to which the electron distribution is heated. The luminescence spectrum is found to be broad and essentially featureless up to a high energy cutoff of approximately 3.7 eV, which is determined...
Transparent thin-film transistors (TTFTs) with an amorphous zinc tin oxide channel layer formed via rf magnetron sputter deposition are demonstrated. Field-effect mobilities of 5–15 and 20–50 cm² V‾¹ s‾¹ are obtained for devices post-deposition annealed at 300 and 600 °C, respectively. TTFTs processed at 300 and 600 °C yield devices...
The internal charge versus phosphor field (Q-Fp) technique is proposed as a method for characterization of the electrical properties of alternating-current thin-film electroluminescent (ACTFEL) devices. Q-Fp analysis provides direct information about the internal behavior of the ACTFEL device. The steady-state field and internal conduction, polarization, leakage, and relaxation charges may...
Offset is observed in the charge–voltage (Q–V) or internal charge–phosphor field (Q–Fp) characteristics of certain alternating-current thin-film electroluminescent (ACTFEL) devices. This offset arises from a displacement along the voltage axis of a transient curve measured across a sense capacitor in the electrical characterization setup. A procedure for adjusting this offset...
Anomalous charge-voltage (Q-V) characteristics are observed for several types of alternating-current thin-film electroluminescent (ACTFEL) devices. These Q-V curves are anomalous because conduction charge flows in these devices exclusively during the portion of the wave form in which the applied voltage is constant, at its maximum value; this kind of conduction...
The effects of supercritical fluid (SCF) impregnation on physical properties of composites were investigated at various pressures, temperatures, and treatment times with carbon dioxide as the fluid and tebuconazole as a biocide. In general, within the ranges tested, SCF treatment had no negative effects on modulus of rupture (MOR), modulus...
A small-scale test was developed to evaluate the ability of fungicides to control decay fungi established in wood. The test, which uses blocks 2.5 x 2.5 x 10 cm, tests the ability of a chemical to migrate from the middle of the block to control a previously established decay fungus,...
Transparent films of CuScO₂₊ₓ have been prepared which show p-type electrical conductivity. The temperature dependence of the conductivity indicates semiconducting behavior with an apparent room temperature activation energy of 0.11 eV. The highest room temperature conductivity observed was 30 S cm⁻1. Films 110 nm thick show 40% transparency in most...
This report describes the relationship of incising-induced strength loss in bending as a function of preservative treatment and incising pattern, density, and depth of penetration for various machine stress-rated (MSR) grades of full-size 2 by 4 Douglas-fir, Hem-Fir, and Spruce-Pine-Fir (South) dimension lumber. This study may represent a worst-case "incising...
The authors analyze electromagnetic modes in multilayered nanocomposites and demonstrate that the response of a majority of realistic layered structures is strongly affected by the nonlocal effects originating from strong field oscillations across the system, and is not described by conventional effective-medium theories. They develop the analytical description of the...
The authors study perspectives of nanowire metamaterials for negative-refraction waveguides, high-performance polarizers, and polarization-sensitive biosensors. They demonstrate that the behavior of these composites is strongly influenced by the concentration, distribution, and geometry of the nanowires, derive an analytical description of electromagnetism in anisotropic nanowire-based metamaterials, and explore the limitations of...
Electron avalanche due to intraband optical absorption is discussed as a mechanism responsible for laser induced damage in certain insulating crystals.
We employ two different methods to generate controllable elliptical polarization of teraherz (THz) pulses. First, THz pulses are generated via optical rectification in nonlinear crystals using a pair of temporally separated and perpendicularly polarized optical pulses. The THz ellipticity is controlled by adjusting the relative time delay and polarization of...
We demonstrate a technique for terahertz pulse shaping via optical rectification in the pre-engineered domain structure of poled lithium niobate crystals. The terahertz wave forms coincide with the crystal domain structures. The one-dimensional nonlinear wave equation simulates the experimental results with a good qualitative agreement.
The authors demonstrate an efficient room temperature source of terahertz radiation using femtosecond laser pulses as a pump and GaAs structures with periodically inverted crystalline orientation, such as diffusion-bonded stacked GaAs and epitaxially grown orientation-patterned GaAs, as a nonlinear optical medium. By changing the GaAs orientation-reversal period (504–1277 μm), or...
We report on the effect of various guest molecules added to a functionalized anthradithiophene (ADT) host on photoexcited charge carrier dynamics in solution-deposited thin films, from ~100 ps to >100 μs after photoexcitation with 100 fs laser pulses. An addition of 2 and 5 wt % of C60 to a...
We demonstrate color shifting from the yellow to the red in the electroluminescence from (ZnGa)S:Mn films. We observe threshold voltages down to about 35 V, extremely low for such devices. We discuss the materials characteristics of the phosphor films, and the potential for improvement of the luminous intensity of the...
We derive an approach to determine the causal direction of wavevectors of modes in optical metamaterials, which, in turn, determines signs of refractive index and impedance as a function of real and imaginary parts of dielectric permittivity and magnetic permeability. We use the developed technique to demonstrate that the interplay...
We analyze the performance of a planar lens based on realistic negative index material in a generalized geometry. We demonstrate that the conventional superlens design (where the lens is centered between the object and the image) is not optimal from the resolution point of view, develop an analytical expression for...
High electron mobility thin films of In₂₋ₓWₓO₃₊y(0≤x≤0.075) were prepared on amorphous SiO₂ and single-crystal yttria-stablized zirconia (001) substrates by pulsed laser deposition. Mobilities ranged between 66 and 112 cm² /Vs depending on the substrate type and deposition conditions, and the highest mobility was observed at a W-dopant concentration of x~0.03....
Radioactive In has been incorporated into oriented thin films of YBa₂Cu₃O₇₋δ during a thermal coevaporation process. The hyperfme technique of perturbed γγ-angular correlation spectroscopy shows that 60% of the indium substitutes at a single site in the superconductor. We obtain spectra with reasonable statistics from 2 mCi of starting material,...
BaCuQF (Q=S,Se) materials, candidate transparent p-type conductors, were prepared by solid-state reaction, and their bulk electrical and optical properties were evaluated. The room-temperature Seebeck coefficient and electrical conductivity of undoped BaCuQF pellets were +56 μV/K and 0.088 S/cm, respectively, for the sulfide fluoride, and +32 μV/K and 0.061 S/cm, respectively,...
A unique approach for obtaining bright and efficient saturated green phosphors for alternating-current thin-film electroluminescent (ACTFEL) device applications is presented. The approach involves color-shifting blue SrS:Cu,F ACTFEL phosphors into the green region of the spectrum via the incorporation of alkali metal ions into the SrS lattice. Alkali metals are incorporated...
ASTM standard sizes for bending tests (either 50 × 50 mm or 25 × 25 mm in cross-section) are not always suitable for research purposes that characterize smaller sections of wood. Moreover, the ASTM standards specify loading the sample on the longitudinal-tangential surface. If specimens are small enough, then the...
To study whether pruning young Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) hastens the transition from juvenile to mature wood, we investigated the effects on wood properties in an intensively managed young plantation in the Coast Range of Oregon. Ten years after trees were pruned to a fixed height (3.4...
We report on a novel class of semiconductor metamaterials that employ a strongly anisotropic dielectric function to achieve negative refraction in the midinfrared region of the spectrum, ~8.5–13 μm. We present two types of metamaterials, layered highly doped/undoped heterostructures and quantum well superlattices that are highly anisotropic. Contrary to other...
The authors demonstrate the generation of multicycle narrow-bandwidth terahertz pulses in periodically inverted GaAs structures using optical rectification of 2 μm, 100 fs pump pulses. Three different types of orientation-inverted samples are employed: optically contacted multilayer, orientation-patterned, and diffusion-bonded GaAs. The terahertz pulses are characterized by two-color (pump at 2...
The fauna of parasitic isopods of the family Bopyridae in Singapore is only poorly known, consisting of only seven species in as many genera in five subfamilies. A new small collection adds four species in as many genera, two of them belonging to a subfamily not previously recorded from Singapore....
The accelerated diagenesis, maturation, and catagenesis of organic matter to hydrothermal petroleum was studied in sediments from Ocean Drilling Program Leg 139 in Middle Valley, northern Juan de Fuca Ridge. Sediments at Sites 855 and 856 have experienced high heat flow resulting in accelerated diagenesis of the immature organic matter...
Ocean Drilling Program (ODP) Leg 202 has opened a new window
into understanding late Paleogene and Neogene global environmental
change by providing high-quality sediment sequences from a previously
unsampled region, the eastern South Pacific. Eleven sites (1232–
1242) that record variations on timescales ranging from decades to tens
of millions...
High-temperature combustion oxidation measurements of nonvolatile dissolved organic carbon (DOC) have been determined for pore waters from sediments of Middle Valley, Ocean Drilling Program Leg 139, as well as for overlying and near-bottom seawater. The DOC values in the interstitial waters are generally greater than those in the overlying water...
The high decay resistance of western redcedar (Thuja plicata Donn) is due to the presence of toxic extractives, called tropolones, in the heartwood. Therefore, tropolone content may be used as an indicator of decay resistance. With increment core-sized samples of western redcedar heartwood, we used gas chromatography to measure tropolone...
Extractives can account for between 1 to 20% of the oven-dry weight of wood of various tree species and can influence wood density values appreciably. Removing these chemical deposits (extraction)in wood samples can help establish a consistent baseline for comparing wood densities where extractives are expected to differ between sample...
This paper hypothesizes a correlation in some species between the cambial age of transition from core (juvenile) to outer (mature) wood and the cambial age of transition from photosynthetic to non-photosynthetic bark. Secondly, this paper hypothesizes that the relationship is causal: a signal produced in relation to the photosynthetic bark...
Six 40-year-old red alders (Alnus rubra Bong.) were harvested from a mixed stand of A. rubra and big-leaf maple (Acer macrophyllum Pursh) in the Oregon Coast Range to evaluate variation in their wood characteristics at two heights. Because the trees had a slight lean (4 to 14°), we sampled along...
We sampled boles, branches, and roots of four Douglas-fir (Pseudotsuga menziesii var. menziesii) trees to learn a) whether branches and roots have a zone of juvenile wood, defined as a zone with progressive changes in wood density and/or tracheid length from the pith outward at successively greater cambial
ages, and...
The air permeability of western hemlock from coastal forests in western Oregon was assessed. Permeability varied widely among trees, as well as by position within individual trees. Permeability tended to decrease with distance inward from the bark, a trend implying that this species produces a heartwood zone. These variations may...
The effect of process variations under supercritical conditions on cyproconazole retention and distribution in ponderosa pine sapwood boards was assessed. While pressure and temperature appeared to affect biocide solubility to some extent, the overall results suggested that biocide movement into wood was influenced more by diffusion than bulk flow. Biocide...
Preservative treatment of whole, wood-based composite products (mainly panels) has disadvantages; problems largely stem from swelling, strength loss, and incomplete or inappropriate penetration during treatment, and distortion during redrying. Pretreatment of comminuted wood prior to mat lay-up is one alternative, though the addition of chemicals may affect bonding during subsequent...
Although boron has many advantages as a wood preservative, this chemical performs poorly in leaching exposures. In this study, we investigated the potential for decreasing the leachability of boron preservatives with polyethylene glycol (PEG). Southern pine (Pinus spp.) test samples impregnated with combinations of sodium borate or boric acid and...
Sedimentary pore fluids from the Chile Triple Junction were sampled in situ, and analyzed for their noble gas composition. ³He/⁴He and ⁴He/Ne ratios were used to evaluate the fraction of helium in the samples that originated from mantle and radiogenic sources. The results show no primordial helium in samples recovered...
Coring at ODP Sites 859, 860, and 861 near the Chile Triple Junction failed to recover anticipated gas hydrate that was inferred
to be present from two lines of geophysical evidence: pre-cruise observation of a weak to strong bottom simulating reflector (BSR)
marking the predicted base of the gas-hydrate stability...
Experiments were designed to determine whether and how steelhead Oncorhynchus mykiss affect chinook salmon O. tshawytscha when the two species are confined together. In a behavioral experiment, we observed groups of juvenile chinook salmon and steelhead together and groups of chinook salmon alone to determine whether the steelhead were aggressive...
Juvenile chinook salmon Oncorhynchus tshawytscha were subjected to handling and tagging protocols typical of normal hatchery operations and monitored for their physiological response to stress. Treatments included coded-wire-tagging, counting, ventral fin clipping, adipose fin clipping, and a procedure simulating a pond split. Treatment fish were also subjected to a standardized...
Twenty-two steelhead trout (Salmo gairdneri) containing coded wire tags (CWT's) were captured in gillnets fished by the Oshoro-Maru in the Gulf of Alaska and along 180 during 1982-85. These fish originated from North American streams and hatcheries in British Columbia, Idaho, and Washington. One fish was age 0.1, 16 were...
Although much is known about the effects of electroshock on fish physiology, consequences to the immune system and disease progression have not received attention. Our objectives were to determine the effects of electroshock on selected immune function in juvenile spring chinook salmon Oncorhynchus tshawytscha, the mechanism of any observed alteration,...