WorldWideScience

Sample records for pseudotsuga menziesii stands

  1. Occurrence of Piloderma fallax in young, rotationage, and old-growth stands of Douglas-fir (Pseudotsuga menziesii) in the Cascade Range of Oregon, U.S.A.

    Science.gov (United States)

    J.E. Smith; R. Molina; M.M.P. Huso; M.J. Larsen

    2000-01-01

    Yellow mycelia and cords of Piloderma fallax (Lib.) Stalp. were more frequently observed in old-growth stands than in younger managed stands of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Piloderma fallax frequency and percent cover data were collected from 900 plots in three replicate stands in...

  2. Species richness, abundance, and composition of hypogeous and epigeous ectomycorrhizal fungal sporocarps in young, rotation-age, and old-growth stands of Douglas-fir (Pseudotsuga menziesii) in the Cascade Range of Oregon, U.S.A.

    Science.gov (United States)

    J.E. Smith; R. Molina; M.M.P. Huso; D.L. Luoma; D. McKay; M.A. Castellano; T. Lebel; Y. Valachovic

    2002-01-01

    Knowledge of the community structure of ectomycorrhizal fungi among successional forest age-classes is critical for conserving fungal species diversity. Hypogeous and epigeous sporocarps were collected from three replicate stands in each of three forest age-classes (young, rotation-age, and old-growth) of Douglas-fir (Pseudotsuga menziesii (Mirb.)...

  3. A taper function for Pseudotsuga menziesii plantations in Spain ...

    African Journals Online (AJOL)

    Five stem taper models belonging to three different taper function categories were fitted to data corresponding to 282 Pseudotsuga menziesii trees. The trees were selected in the area surrounding 61 research plots installed in Galicia, Asturias and the Basque Country, northern Spain. The models were simultaneously fitted ...

  4. Species-mediated soil moisture availability and patchy establishment of Pseudotsuga menziesii in chaparral.

    Science.gov (United States)

    Dunne, Jennifer A; Parker, V Thomas

    1999-04-01

    The occurrence of mature individuals of Pseudotsuga menziesii in stands of Arctostaphylos species mark the initial stages of mixed evergreen forest invasion into chaparral in central coastal California. We planted two cohorts of P. menziesii seeds at three sites under stands of two Arctostaphylos species and Adenostoma fasciculatum in order to determine whether first-year seedling emergence and survival, particularly during the regular summer drought, underlie the spatial distribution of mature trees observed in chaparral. Regardless of the chaparral species they were planted under, P. menziesii seeds that were not protected from vertebrate predation displayed very little emergence and no survival. In contrast, emergence of P. menziesii that were protected from vertebrate predators was much higher but still did not significantly differ among the three chaparral species. However, survival of protected seedlings under Arctostaphylos glandulosa was much greater than under A. fasciculatum, with intermediate survival under Arctostaphylos montana. While mortality of protected seedlings due to insect herbivory, fungal infection, and disturbance displayed no consistent patterns, summer drought mortality appeared to drive the patterns of survival of P. menziesii under the different chaparral species. These emergence, mortality, and survival data suggest that spatial patterns of P. menziesii recruitment in chaparral are driven by first-year summer drought seedling mortality, but only in years when seeds and seedlings are released from vertebrate predation pressure. Because the first-year drought mortality and survival patterns of P. menziesii seedlings differed strongly depending on the chaparral species, we examined the additional hypothesis that these patterns are associated with differences in the availability of soil moisture under different chaparral species. Both higher survival and lower drought mortality of P. menziesii seedlings were associated with higher soil

  5. MORFOGÉNESIS IN VITRO DE Pseudotsuga menziesii VAR. glauca

    Directory of Open Access Journals (Sweden)

    María Guadalupe Carrillo-Benítez

    2011-01-01

    Full Text Available Se evaluó la respuesta morfogénica a partir de embriones cigóticos cultivados in vitro de semilla almacenada (un año de Pseudotsuga menziesii var. glauca recolectada en Tlaxcala. Las semillas fueron desinfestadas con detergente y H2O2 (3 % v/v durante 48 h en agitación a 50 rpm, cultivadas en el medio de Murashige y Skoog (1962 sin reguladores. La germinación ocurrió después de siete días y posteriormente subcultivados a un medio MS con 2,4-D (3 mg·L-1 y BA (1 mg·L-1. Con los callos obtenidos en un medio HS se evaluaron tres concentraciones de ABA para promover formación de estructuras embrionarias, presentándose el mejor tratamiento con concentración de 10.0 mg·L-1 (P<.0001. El mejor desarrollo de plántulas se presentó empleando un medio Murashige y Skoog (1962 con sacarosa al 6 %. Se usaron micorrizas para mejor adaptación de plántulas a suelo. No hubo formación de raíces.

  6. Fungal endophytes in woody roots of Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa)

    Science.gov (United States)

    J. A. Hoff; Ned B. Klopfenstein; Geral I. McDonald; Jonalea R. Tonn; Mee-Sook Kim; Paul J. Zambino; Paul F. Hessburg; J. D. Rodgers; T. L. Peever; L. M. Carris

    2004-01-01

    The fungal community inhabiting large woody roots of healthy conifers has not been well documented. To provide more information about such communities, a survey was conducted using increment cores from the woody roots of symptomless Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) growing in dry forests...

  7. A sex-averaged genetic linkage map in coastal Douglas-fir (Pseudotsuga menziesii [Mirb] Franco var menziesii) based on RFLP and RAPD markers

    Science.gov (United States)

    K.D. Jermstad; D.L. Bassoni; N.C. Wheeler; D.B. Neale

    1998-01-01

    We have constructed a sex-averaged genetic linkage map in coastal Douglas-fir ( Pseudotsuga menziesii [Mirb.] Franco var menziesii) using a three-generation outcrossed pedigree and molecular markers. Our research objectives are to learn about genome organization and to identify markers associated with adaptive traits. The map...

  8. Variation in phenology and monoterpene patterns of defoliated and nondefoliated Douglas-fir (Pseudotsuga menziesii var. glauca).

    Science.gov (United States)

    Rose-Marie Muzika; Judith Engle; Catherine Parks; Boyd. Wickman

    1993-01-01

    Foliage was collected from paired Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) trees characterized as either "resistant" or "susceptible" western spruce budworm (Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae) attack. Resistant trees produced more...

  9. Comparative genetic responses to climate for the varieties of Pinus ponderosa and Pseudotsuga menziesii: realized climate niches

    Science.gov (United States)

    Gerald E. Rehfeldt; Barry C. Jaquish; Javier Lopez-Upton; Cuauhtemoc Saenz-Romero; J. Bradley St Clair; Laura P. Leites; Dennis G. Joyce

    2014-01-01

    The Random Forests classification algorithm was used to predict the occurrence of the realized climate niche for two sub-specific varieties of Pinus ponderosa and three varieties of Pseudotsuga menziesii from presence-absence data in forest inventory ground plots. Analyses were based on ca. 271,000 observations for P. ponderosa and ca. 426,000 observations for P....

  10. Ecological adaptations in Douglas-fir (Pseudotsuga menziesii var. glauca) populations: I. North Idaho and North-East Washington

    Science.gov (United States)

    Gerald E. Rehfeldt

    1979-01-01

    Growth, phenology and frost tolerance of seedlings from 50 populations of Douglas-fir (Pseudotsuga menziesii var. glauca) were compared in 12 environments. Statistical analyses of six variables (bud burst, bud set, 3-year height, spring and fall frost injuries, and deviation from regression of 3-year height on 2-year height) showed that populations not only differed in...

  11. Origin matters! Difference in drought tolerance and productivity of coastal Douglas-fir (Pseudotsuga menziesii (Mirb.)) provenances

    NARCIS (Netherlands)

    Eilmann, B.; Vries, de S.M.G.; Ouden, den J.; Mohren, G.M.J.; Sauren, P.; Sass, U.G.W.

    2013-01-01

    Forests of the future should be resistant to exacerbating climatic conditions, especially to increasing drought, but at the same time provide a sufficient amount and quality of timber. In this context coastal Douglas-fir (Pseudotsuga menziesii (Mirb.)) is a promising species since it remains

  12. Influence of a sand soil plough base on the growth of Douglas fir (Pseudotsuga menziesii (MIRB.) FRANCO).

    NARCIS (Netherlands)

    Gruber, F; Nick, L

    The root/shoot growth of eight year old Douglas fir trees (Pseudotsuga menziesii (MIRB.) FRANCO) planted on ploughed agricultured land in the first generation was investigated. One half of the field was 60 cm deeply ploughed before afforestation. The second half was not deeply ploughed and was

  13. Effects of seed source origin on bark thickness of Douglas-fir (Pseudotsuga menziesii) growing in southwestern Germany

    Science.gov (United States)

    Ulrich Kohnle; Sebastian Hein; Frank C. Sorensen; Aaron R. Weiskittel

    2012-01-01

    Provenance-specific variation in bark thickness in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is important for accurate volume calculations and might carry ecological implications as well. To investigate variation, diameter at breast height (dbh) and double bark thickness (dbt) were measured in 10 experiments in southwestern Germany (16...

  14. Resin duct size and density as ecophysiological traits in fire scars of Pseudotsuga menziesii and Larix occidentalis.

    Science.gov (United States)

    Arbellay, Estelle; Stoffel, Markus; Sutherland, Elaine K; Smith, Kevin T; Falk, Donald A

    2014-10-01

    Resin ducts (RDs) are features present in most conifer species as defence structures against pests and pathogens; however, little is known about RD expression in trees following fire injury. This study investigates changes in RD size and density in fire scars of Douglas fir (Pseudotsuga menziesii) and western larch (Larix occidentalis) as a means to evaluate the ecophysiological significance of traumatic resinosis for tree defence and survival. Transverse and tangential microsections were prepared for light microscopy and image analysis in order to analyse axial and radial RDs, respectively. Epithelial cells of RDs and fusiform rays associated with radial RDs were also examined. RDs were compared between normal xylem and wound xylem at four different section heights along the fire-injured stem. Following fire injury, P. menziesii axial RDs narrowed by 38-43 % in the first year after injury, and the magnitude of this change increased with stem height. Larix occidentalis axial RDs widened by 46-50 % in the second year after injury. Radial RDs were of equivalent size in P. menziesii, but widened by 162-214 % in L. occidentalis. Fusiform rays were larger following fire injury, by 4-14 % in P. menziesii and by 23-38 % in L. occidentalis. Furthermore, axial RD density increased in both species due to the formation of tangential rows of traumatic RDs, especially in the first and second years after injury. However, radial RD density did not change significantly. These results highlight traumatic resinosis as a species-specific response. Pseudotsuga menziesii produce RDs of equivalent or reduced size, whereas L. occidentalis produce wider RDs in both the axial and radial duct system, thereby increasing resin biosynthesis and accumulation within the whole tree. Larix occidentalis thus appears to allocate more energy to defence than P. menziesii. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For

  15. Deriving Fuel Mass by Size Class in Douglas-fir (Pseudotsuga menziesii Using Terrestrial Laser Scanning

    Directory of Open Access Journals (Sweden)

    Lloyd Queen

    2011-08-01

    Full Text Available Requirements for describing coniferous forests are changing in response to wildfire concerns, bio-energy needs, and climate change interests. At the same time, technology advancements are transforming how forest properties can be measured. Terrestrial Laser Scanning (TLS is yielding promising results for measuring tree biomass parameters that, historically, have required costly destructive sampling and resulted in small sample sizes. Here we investigate whether TLS intensity data can be used to distinguish foliage and small branches (≤0.635 cm diameter; coincident with the one-hour timelag fuel size class from larger branchwood (>0.635 cm in Douglas-fir (Pseudotsuga menziesii branch specimens. We also consider the use of laser density for predicting biomass by size class. Measurements are addressed across multiple ranges and scan angles. Results show TLS capable of distinguishing fine fuels from branches at a threshold of one standard deviation above mean intensity. Additionally, the relationship between return density and biomass is linear by fuel type for fine fuels (r2 = 0.898; SE 22.7% and branchwood (r2 = 0.937; SE 28.9%, as well as for total mass (r2 = 0.940; SE 25.5%. Intensity decays predictably as scan distances increase; however, the range-intensity relationship is best described by an exponential model rather than 1/d2. Scan angle appears to have no systematic effect on fine fuel discrimination, while some differences are observed in density-mass relationships with changing angles due to shadowing.

  16. Bordered pit structure and function determine spatial patterns of air-seeding thresholds in xylem of Douglas-fir (Pseudotsuga menziesii; Pinaceae) trees.

    Science.gov (United States)

    J.C. Domec; B. Lachenbruch; F.C. Meinzer

    2006-01-01

    The air-seeding hypothesis predicts that xylem embolism resistance is linked directly to bordered pit functioning. We tested this prediction in trunks, roots, and branches at different vertical and radial locations in young and old trees of Pseudotsuga menziesii. Dimensions of bordered pits were measured from light and scanning electron micrographs...

  17. The spatial influence of Pseudotsuga menziesii retention trees on ectomycorrhiza diversity.

    Science.gov (United States)

    D.L. Luoma; C.A. Stockdale; R. Molina; J.L. Eberhart

    2006-01-01

    This study examines the effect of retained green trees on diversity of mycorrhizal fungi after stand harvest. A significant reduction of mycorrhizal root type richness resulted from the harvest treatment. Samples taken under tree crowns showed no significant decline in the mean number of mycorrhiza types per soil core. In areas well removed from retention trees, there...

  18. Basal area increment series of dominant trees of Pseudotsuga menziesii (Mirb. Franco show periodicity according to global climate patterns

    Directory of Open Access Journals (Sweden)

    Luis U. Castruita-Esparza

    2016-01-01

    Full Text Available Las especies forestales como Pseudotsuga menziesii (Mirb. Franco son sensibles al clima y muestran anillos de crecimiento claramente definidos. La selección cuidadosa de árboles dominantes con fuste circular permite el análisis de tendencias de crecimiento arbóreo. En este estudio se utilizaron mediciones directas del incremento del área basal (IAB para explicar las periodicidades biológicas y elaborar predicciones del crecimiento en el abeto Douglas-fir que crece en el oeste de México. Para eliminar el efecto de la edad en el crecimiento de los árboles se hizo un análisis en términos de la edad del cámbium. Los resultados mostraron correlación significativa (P < 0.05 entre IAB y la precipitación de enero a julio. Además, se encontraron periodicidades de 7, 21, 27 y 60 años en el crecimiento de los árboles; el periodo de 60 años fue determinante para la construcción de un modelo ARIMA (0,1,1 para realizar predicciones del IAB en las próximas décadas. Las proyecciones del crecimiento proponen una reducción del IAB en árboles maduros dominantes en las próximas décadas. Dicha reducción es un resultado inesperado, debido a que el IAB en árboles dominantes permanece constante hasta una edad biológica de senescencia. Los resultados concuerdan con una tendencia general de reducción en el crecimiento en otros bosques del mundo debido a estrés hídrico, lo cual sugiere que la variabilidad climática futura puede empeorar la condición de salud del abeto Douglas-fir de los bosques del norte de México.

  19. Comparison of Proanthocyanidins and Related Compounds in Leaves and Leaf-Derived Cell Cultures of Ginkgo bioloba L., Pseudotsuga menziesii Franco, and Ribes sanguineum Pursh 1

    Science.gov (United States)

    Stafford, Helen A.; Kreitlow, Kelly S.; Lester, Hope H.

    1986-01-01

    Proanthocyanidins, flavan-3-ols, and their flavanoid precursors in leaves and leaf-derived callus and cell suspension cultures have been isolated and analyzed by high performance liquid chromatography with C18 columns, paper chromatography, and by chemical and spectrophotometric methods. Cultures of Ginkgo biloba and Pseudotsuga menziesii (Douglas-fir) produced much greater amounts of proanthocyanidins than leaves per milligram dry weight. In cultures, however, the prodelphinidin component relative to that of procyanidins decreased; this was most pronounced in Pseudotsuga. In contrast, callus cultures of Ribes sanguineum accumulated proanthocyanidins in amounts about equal to those in intact leaves per milligram dry weight and the prodelphinidin content remained high. Although Ginkgo and Ribes leaves contained major amounts of flavan-3-ols and dimers with the 2,3-cis-stereochemistry, their cultures tended to synthesize 2,3-trans-isomers instead. Glycosides of flavanone and 3-hydroxyflavanone precursors accumulated in medium to high amounts on a dry weight basis in leaves and cultures of Ribes and Pseudotsuga, and the 3′-glycosidic linkage predominated when the latter species was cultured with 2,4-dichlorophenoxyacetic acid rather than naphthaleneacetic acid. PMID:16665147

  20. Holocene vegetation history and fire regimes of Pseudotsuga menziesii forests in the Gulf Islands National Park Reserve, southwestern British Columbia, Canada

    Science.gov (United States)

    Lucas, Jennifer D.; Lacourse, Terri

    2013-05-01

    Pollen analysis of a 9.03-m-long lake sediment core from Pender Island on the south coast of British Columbia was used to reconstruct the island's vegetation history over the last 10,000 years. The early Holocene was characterized by open mixed woodlands with abundant Pseudotsuga menziesii and a diverse understory including Salix and Rosaceae shrubs and Pteridium aquilinum ferns. The establishment of Quercus garryana savanna-woodland with P. menziesii and Acer macrophyllum followed deposition of the Mazama tephra until ~ 5500 cal yr BP, when these communities gave way to modern mixed P. menziesii forest. Charcoal analyses of the uppermost sediments revealed low charcoal accumulation over the last 1300 years with a mean fire return interval (mFRI) of 88 years. Fires were more frequent (mFRI = 50 yr) during the Medieval Climate Anomaly (MCA) with warm, dry conditions facilitating a higher fire frequency than during the Little Ice Age, when fires were infrequent. Given the projected warming for the next 50-100 years, land managers considering the reintroduction of fire to the Gulf Islands National Park Reserve may want to consider using the mFRI of the MCA as a baseline reference in prescribed burning strategies.

  1. Understorey plant community dynamics following a large, mixed severity wildfire in a Pinus ponderosa-Pseudotsuga menziesii forest, Colorado, USA

    Science.gov (United States)

    Paula J. Fornwalt; Merrill R. Kaufman

    2014-01-01

    In 2002, the Hayman Fire burned across 55 800 ha of Colorado Front Range P. ponderosa-P. menziesii forest. Also burned in the fire were 20 upland and five riparian plots within a 400-ha study area. These plots had been surveyed for understorey plant composition and cover 5-6 yrs prior. We re-measured all plots annually from 2003 to 2007, 1-5 yrs post-fire. Changes in...

  2. Effects of Harvesting Systems and Bole Moisture Loss on Weight Scaling of Douglas-Fir Sawlogs (Pseudotsuga Menziesii var. glauca Franco

    Directory of Open Access Journals (Sweden)

    Jarred D. Saralecos

    2014-09-01

    Full Text Available Characterizing the moisture loss from felled trees is essential for determining weight-to-volume (W-V relationships in softwood sawlogs. Several factors affect moisture loss, but research to quantify the effects of bole size and harvest method is limited. This study was designed to test whether bole size, harvest method, environmental factors, and the associated changes in stem moisture content of felled Douglas-fir (Pseudotsuga menziesii var. glauca Franco affected the weight-to-volume relationship of sawlogs. Thirty trees in three size classes (12.7–25.4 cm, 25.5–38.1 cm, 38.2–50.8 cm were felled and treated with one of two harvesting processing methods. Moisture content was sampled every two days for four weeks. Results showed 6% greater moisture loss in the crowns of stems that retained limbs after felling compared to stems with limbs removed after harvesting. Additionally, moisture loss rate increased as stem size decreased. The smallest size class lost 58% moisture content compared to 34% in the largest size class throughout the study duration. These stem moisture content changes showed a 17% reduction in average sawlog weight within the largest size class, shifting current W-V relationships from 2.33 tons m−3 to 1.94 tons m−3 during the third seasonal quarter for northern Idaho Douglas-fir and potentially altering relationships year-round.

  3. Financial analysis of early stand treatments in southwest Oregon.

    Science.gov (United States)

    Helge Eng; K. Norman Johnson; Roger D. Fight

    1990-01-01

    Management guidelines for economically efficient early stand treatments were developed by identifying treatments that would maximize financial returns over the rotation for coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in southwest Oregon. Short rotations and low stand densities (trees per acre) gave...

  4. Early development of matched planted and naturally regenerated Douglas-fir stands after slash burning in the Cascade Range.

    Science.gov (United States)

    R.E. Miller; R.E. Bigley; S. Webster

    1993-01-01

    We compared matched planted and naturally regenerated plots in 35- to 38- year-old Douglas-fir (Pseudotsuga menziesii var. menziesii) stands at seven locations in western Washington and Oregon. Total number of live stems is similar, but stands planted to Douglas fir average 26 more live stemslac of Douglas-fir and 39 fewer...

  5. Belowground competition from overstory trees influences Douglas-fir sapling morphology in thinned stands

    Science.gov (United States)

    Warren D. Devine; Timothy B. Harrington

    2009-01-01

    We evaluated effects of belowground competition on morphology of naturally established coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) saplings in 60- to 80-year-old thinned Douglas-fir stands in southwestern Washington. We separately quantified belowground competition from overstory and understory sources...

  6. Análisis de sequías y productividad con cronologías de Pseudotsuga menziesii Rob. & Fern., y su asociación con El Niño en el nordeste de México

    Directory of Open Access Journals (Sweden)

    María Rafaela Arreola-Ortiz

    2010-06-01

    Full Text Available Con tres cronologías de Pseudotsuga menziesii Mirb. Franco obtenidas en la Sierra Madre Oriental (SMO, en el estado de Nuevo León, México, se determinaron periodos de sequías y productividad analizando el patrón de crecimiento radial durante un lapso de 120 años. Se estudió la asociación entre el índice de crecimiento radial de las cronologías y los registros instrumentales de factores climáticos (precipitación y temperatura, obtenidos de cuatro estaciones meteorológicas vecinas a los sitios de muestreo. Se asociaron las cronologías con el índice multivariado del ENSO (MEI. Los resultados indican que en las cronologías resaltan cuatro periodos de sequías que se presentaron entre los años: 1885-1903, 1907-1937, 1950-1963 y 1998-2003. La productividad disminuye notablemente de 1.18 mm año-1 de crecimiento radial en épocas húmedas a 0.82 mm año-1 durante la presencia de sequías. Existe buena asociación entre el Índice de Crecimiento Radial Estandarizado (ICRE de las cronologías con la precipitación invernal observada. La reconstrucción de la precipitación invernal basada en las cronologías, muestra un ascenso paulatino a través del tiempo, desde 1880 hasta 2003. La correlación del ICRE de las tres cronologías y el MEI presenta buena asociación en la mayoría de los meses del año, principalmente, durante los meses que cubren las estaciones de otoño, invierno y primavera, indicando que el crecimiento del ancho de los anillos se ve favorecido con la presencia de bajas temperaturas y precipitaciones por arriba del promedio durante el invierno o la etapas primarias de la primavera.

  7. Tree microhabitat structures as indicators of biodiversity in Douglas-fir forests of different stand ages and management histories in the Pacific Northwest, U.S.A.

    Science.gov (United States)

    Alexa K. Michel; Susanne. Winter

    2009-01-01

    In this study, microhabitat structures in Douglas-fir (Pseudotsuga menziesii) forests were defined and their frequency and abundance in natural stands and stands of varying active management histories and stand ages was compared. Indicator microhabitat structures for natural forests were determined and the relationship of the abundance of...

  8. Respiration , nitrogen fixation, and mineralizable nitrogen spatial and temporal patterns within two Oregon Douglas-fir stands.

    Science.gov (United States)

    Sharon M. Hope; Ching-Yan. Li

    1997-01-01

    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...

  9. Acoustic Evaluation of Thinning and Biosolid Fertilization Effects on Wood Quality of a Douglas-fir stand

    Science.gov (United States)

    Xiping Wang; Robert J. Ross; Steve Verrill; Eini Lowell; Jamie Barbour

    2015-01-01

    In this study, we examined the potential of using a time-of-flight (TOF) acoustic wave method to evaluate thinning and biosolid fertilization effects on acoustic velocity of trees and modulus of elasticity (MOE) of structural lumber in a 76-year-old Douglas-fir (Pseudotsuga menziesii, (Mirb., Franco)) experimental stand. The stand consisted of four...

  10. WestPro: a computer program for simulating uneven-aged Douglas-fir stand growth and yield in the Pacific Northwest.

    Science.gov (United States)

    Rebecca Ralston; Joseph Buongiorno; Benedict Schulte; Jeremy. Fried

    2003-01-01

    WestPro is an add-in program designed to work with Microsoft Excel to simulate the growth of uneven-aged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the Pacific Northwest region of the United States. Given the initial stand state, defined as the number of softwood and hardwood trees per acre by diameter class, WestPro predicts the...

  11. Stand-level gas-exchange responses to seasonal drought in very young versus old Douglas-fir forests of the Pacific Northwest, USA

    Science.gov (United States)

    Sonia Wharton; Matt Schroeder; Ken Bible; Matthias Falk; Kyaw Tha Paw U

    2009-01-01

    This study examines how stand age affects ecosystem mass and energy exchange response to seasonal drought in three adjacent Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests. The sites include two early seral (ES) stands (0 to 15 years old) and an old-growth (OG) (~450 to 500 years old) forest in the Wind River Experimental Forest,...

  12. Growth and yield of all-aged Douglas-fir -- western hemlock forest stands: a matrix model with stand diversity effects.

    Science.gov (United States)

    Jingjing Liang; Joseph Buonglorno; Robert A. Monserud

    2005-01-01

    A density-dependent matrix model was developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) -- western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest stands in the Pacific Northwest of the United States. The model predicted the number and volume of trees for 4 species groups and 19 diameter classes. The parameters...

  13. Establishment and growth of native hardwood and conifer seedlings underplanted in thinned Douglas-fir stands.

    Science.gov (United States)

    Kathleen G. Maas-Hebner; William H. Emmingham; David L. Larson; Samuel S. Chan

    2005-01-01

    Five conifers and two hardwoods native to the Pacific Northwest were planted under four overstory densities of 30-year-old plantations of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Oregon Coast Range, USA. Stand treatments were unthinned (547 trees ha-1), narrow thin (252 trees ha-1),...

  14. Modelling dominant height growth in plantations of Pseudotsuga ...

    African Journals Online (AJOL)

    A model for predicting dominant height growth and site index of Pseudotsuga menziesii (Mirb.) Franco in Spain was constructed. Data from stem analysis of 117 site trees were used. Four dynamic equations using the algebraic difference approach (ADA) and its generalisation (GADA), which have provided good results in ...

  15. Douglas-fir forests in the Oregon and Washington Cascades: relation of the herpetofauna to stand age and moisture

    Science.gov (United States)

    Bury, R. Bruce; Corn, P.S.

    1988-01-01

    Pitfall traps effectively sampled amphibians but not reptiles in Douglas-fir (Pseudotsuga menziesii) forests. The abundance of only one amphibian species varied across an age gradient or a moisture gradient. Salamanders and frogs that breed in ponds or streams were captured in large numbers in some stands, likely due to the presence of nearby breeding habitat rather than forest conditions. Lizards occurred mostly in dry stands and clearcuts. Time-constrained searches showed different use of downed woody debris among terrestrial salamanders. The occurrence and abundance of species in naturally regenerated forests markedly differed from clearcut stands.

  16. Characterization and possible origins of isolated douglas fir stands on the Colorado Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Spence, J.R. [National Park Service, Page, AZ (United States)

    1995-09-01

    The floristic composition of several isolated stands of Pseudotsuga menziesii on the Colorado Plateau is compared. All occurred between 1700-2000 meters, which was about 300-500 meters below typical lower limits for the species. Most stands showed evidence of reproduction and recruitment. A small widespread group of species existed that was common to all stands, but beta diversity was high. A preliminary analysis of possible origins of the stands suggested that they are relictual from the late Wisconsin or early Holocene. Bird-dispersed species were less prevalent than expected compared with existing high elevation conifer forests. These stands represent important resources for Quaternary research, but are extremely vulnerable to human-caused disturbances. It is recommended that they be provided protection from disturbance through appropriate management activities of the various land management agencies.

  17. Climate-related genetic variation in drought-resistance of Douglas-fir ( Pseudotsuga menziesii )

    Science.gov (United States)

    Sheel Bansal; Constance A. Harrington; Peter J. Gould; J. Bradley St.Clair

    2014-01-01

    There is a general assumption that intraspecific populations originating from relatively arid climates will be better adapted to cope with the expected increase in drought from climate change. For ecologically and economically important species, more comprehensive, genecological studies that utilize large distributions of populations and direct measures of traits...

  18. Induced compression wood formation in Douglas fir (Pseudotsuga menziesii) in microgravity

    Science.gov (United States)

    Kwon, M.; Bedgar, D. L.; Piastuch, W.; Davin, L. B.; Lewis, N. G.

    2001-01-01

    In the microgravity environment of the Space Shuttle Columbia (Life and Microgravity Mission STS-78), were grown 1-year-old Douglas fir and loblolly pine plants in a NASA plant growth facility. Several plants were harnessed (at 45 degrees ) to establish if compression wood biosynthesis, involving altered cellulose and lignin deposition and cell wall structure would occur under those conditions of induced mechanical stress. Selected plants were harnessed at day 2 in orbit, with stem sections of specific plants harvested and fixed for subsequent microscopic analyses on days 8, 10 and 15. At the end of the total space mission period (17 days), the remaining healthy harnessed plants and their vertical (upright) controls were harvested and fixed on earth. All harnessed (at 45 degrees ) plant specimens, whether grown at 1 g or in microgravity, formed compression wood. Moreover, not only the cambial cells but also the developing tracheid cells underwent significant morphological changes. This indicated that the developing tracheids from the primary cell wall expansion stage to the fully lignified maturation stage are involved in the perception and transduction of the stimuli stipulating the need for alteration of cell wall architecture. It is thus apparent that, even in a microgravity environment, woody plants can make appropriate corrections to compensate for stress gradients introduced by mechanical bending, thereby enabling compression wood to be formed. The evolutionary implications of these findings are discussed in terms of "variability" in cell wall biosynthesis.

  19. Breeding graft-compatible Douglas-fir rootstocks (Pseudotsuga menziesii (Mirb.) Franco).

    Science.gov (United States)

    D.L. Copes

    1999-01-01

    A study encompassing 24 years was conducted to determine if a breeding program could produce highly graft-compatible rootstocks. Twenty-seven trees of apparent high graft compatibility were selected and crossed to produce 226 control-pollinated families. Seedlings were grown, field planted, and grafted with test scions. Graft unions from field tests were evaluated...

  20. FIRE RESISTANCE OF DOUGLAS FIR [Pseudotsuga menziesii (Mirb. Franco] WOOD TREATED WITH SOME CHEMICALS

    Directory of Open Access Journals (Sweden)

    M. Kemal YALINKILIÇ

    1998-02-01

    Full Text Available Combustible properties of treated douglas wood specimens and fire-retardancy of some preservatives were tested in this study. Crib test of ASTM E 160-150 was followed. Results indicated that, aqueous solutions of boric acid (BA, borax (Bx (Na2BO7 10H2O or BA + Bx mixture (7: 3, w: w had fire retardant efficacy (FRE over untreated wood and reduced the combustibility of vinil monomers (Styrene and methylmetacrylate which were applied as secondary treatment.

  1. Douglas-fir growth in mountain ecosystems: water limits tree growth from stand to region

    Science.gov (United States)

    Jeremy S. Littell; David L. Peterson; Michael Tjoelker

    2008-01-01

    The purpose of this work is to understand the nature of growth-climate relationships for Douglas-fir (Pseudotsuga menziesii) across the climatic dimensions of its niche. We used a combination of biophysically informed sampling (to identify sample sites) and dendroclimatology (to identify growth-climate relationships) along a climate gradient in...

  2. Douglas fir (pseudotsuga menziesii) plantlets responses to as, PB, and sb-contaminated soils from former mines.

    Science.gov (United States)

    Bonet, Amandine; Pascaud, Grégoire; Faugeron, Céline; Soubrand, Marilyne; Joussein, Emmanuel; Gloaguen, Vincent; Saladin, Gaëlle

    2016-01-01

    Phytoremediation of metalloids by conifers is not widely studied although they may be relevant for several contaminated sites, especially those located in cold areas and sometimes under dry climates. Here, seeds of Douglas fir were sown in greenhouse on three soils collected in two French former mines: a gold mine (soils L1 and L2) and a lead and silver mine (soil P). These soils are highly contaminated by Pb, As, and Sb at different concentrations. Plants were harvested after ten weeks. Growth parameters, primary metabolite content, and shoot and root ionomes were determined. Douglas firs grown on the soils L1 and P had a lower biomass than controls and a higher oxidation status whereas those grown on the soil L2 exhibited a more developed root system and only slight modifications of carbon and nitrogen nutrition. Based on trace element (TE) concentrations in shoots and roots and their translocation factor (TF), Douglas fir could be a relevant candidate for As phytoextraction (0.8 g. kg(-1) dry weight in shoots and a TF of 1.1) and may be used to phytostabilize Pb and Sb (8.8 g and 127 mg. kg(-1) in roots for Pb and Sb, respectively, and TF lower than 0.1).

  3. Impact of climate change on cold hardiness of Douglas-fir (Pseudotsuga menziesii): Environmental and genetic considerations

    Science.gov (United States)

    Sheel Bansal; Bradley J. St. Clair; Constance A. Harrington; Peter J. Gould

    2015-01-01

    The success of conifers over much of the world’s terrestrial surface is largely attributable to their tolerance to cold stress (i.e., cold hardiness). Due to an increase in climate variability, climate change may reduce conifer cold hardiness, which in turn could impact ecosystem functioning and productivity in conifer-dominated forests. The expression of cold...

  4. Identification of varieties and gene flow in Douglas fir exemplified in artificially established stands in Germany

    Directory of Open Access Journals (Sweden)

    Barbara Fussi

    2013-12-01

    Full Text Available Douglas-fir [Pseudotsuga menziesii (Mirb. Franco] is an economically valuable non-native tree species in Germany and is considered very promising in view of global climate change. Therefore, the genetic characterization of Douglas-fir populations and seed stands in Germany is essential. We studied coastal and interior Douglas-fir varieties, both present in Germany, by using eleven isoenzyme and four microsatellite loci. By analyzing eight reference populations of known origin we were able to identify the two varieties on the population level using Bayesian and distance based methods. Seven populations present in Bavaria were then successfully assigned to one of the two varieties. Within varieties we found stronger grouping within the interior variety than within the coastal one. Despite lower differences within coastal Douglas-fir we have first indications for the origin of two populations. For two Bavarian populations, natural regeneration was included and genetic data revealed no significant genetic difference between adults and offspring. The parentage analysis for one of the studied stands revealed that a large proportion of adults took part in the reproduction, but some trees were more successful than others in transferring their genes to the next generation. Our study was able to improve variety identification of Douglas-fir using isoenzyme markers and nuclear microsatellites and study reproductive patterns, both are important issues for the management of Douglas-fir stands in Bavaria.

  5. Técnicas de inoculación de abeto de Douglas (Pseudotsuga menziesi (Mirb.) Franco) con los hongos Ectomicorrícicos y su aplicación en reforestación

    OpenAIRE

    Parladé Izquierdo, Xavier

    2011-01-01

    Descripció del recurs: el 21 setembre 2011 Pendent El objetivo principal de este trabajo es la aplicación de técnicas de inoculación de platnas de abeto de Douglas (Pseudotsuga menziesii (Mirb.)Franco) con hongos ectomicorrícicos seleccionados para las condiciones españolas, con el objetivo de mejorar la calidad de planta de reforestación. Primeramente se ha realizado un proceso de selección de hongos por hábitat, especie asociada, capacidad de crecimiento en cultivo y formación de mico...

  6. Productivity and Cost of Integrated Harvesting of Wood Chips and Sawlogs in Stand Conversion Operations

    Directory of Open Access Journals (Sweden)

    Hunter Harrill

    2012-01-01

    Full Text Available This study evaluated the operational performance and cost of an integrated harvesting system that harvested sawlogs and biomass (i.e., energy wood chips in stand conversion clearcut operations. Douglas-fir (Pseudotsuga menziesii trees were processed into sawlogs while whole trees of tanoak (Lithocarpus densiflorus, and sub-merchantable materials (small-diameter trees, tops and limbs were fed directly into a chipper to produce biomass for energy production. A standard time study method was used to determine productivity and costs. Over 26 working days, the integrated system produced 1,316 bone-dry metric tonnes (BDTs of sawlogs, and 5,415.89 BDT of chips, with an average moisture content of 43.2%. Using the joint products allocation costing method, the costs of the integrated system were $29.87/BDT for biomass and $4.26/BDT for sawlogs. Chipping utilization was as low as 41%, directly affecting production and cost of chipping operation. Single-lane, dirt, spur roads were the most costly road type to transport whole trees to a centralized processing site: transportation costs for biomass and sawlogs were increased by $0.08/BDT and $0.02/BDT, respectively, for every 50 meter increase in traveling distance. Diesel fuel price could raise total system cost for each product by $0.78/BDT and $0.08/BDT for each $0.10/liter increase.

  7. Amsinckia menziesii (Lehm.) Nels. & Macbr. in een graanveld bij Venray

    NARCIS (Netherlands)

    Leys, H.N.; Bannink, J.F.

    1965-01-01

    Amsinckia menziesii (Lehm.) Nels. & Macbr., a species occurring in western North America on moist slopes and fields, open valley floors and hillsides, has been found very rarely in 5 places of our country (Gorinchem 1913, Renesse 1952 and 1958, Wageningen 1963, Blauwkapel 1963, Rockanje 1963). In an

  8. Basal area growth, carbon isotope discrimination, and intrinsic water use efficiency after fertilization of Douglas-fir in the Oregon Coast Range

    Science.gov (United States)

    Many hectares of intensively managed Douglas-fir (Pseudotsuga menziesii Mirb. Franco) stands in western North America are fertilized with nitrogen to increase growth rates. Understanding the mechanisms of response facilitates prioritization of stands for treatment. The objective ...

  9. Modeling crown structural responses to competing vegetation control, thinning, fertilization, and Swiss needle cast in coastal Douglas-fir of the Pacific Northwest, USA.

    Science.gov (United States)

    A.R. Weiskittel; D.A. Maguire; R.A. Monserud

    2007-01-01

    Crown structure is a key variable influencing stand productivity, but its reported response to various stand factors has differed. This can be partially attributed to lack of a unified study on crown response to intensive management or stand health. In this analysis of several Douglas-fir (Pseudotsuga menziesii var. menziesii [...

  10. The effects of Douglas fir monoculture on stand characteristics in a zone of Montane beech forest

    Directory of Open Access Journals (Sweden)

    Kostić Olga

    2016-01-01

    Full Text Available The right choice of tree species to form forest cultures is of paramount importance to the preservation of the diversity, fertility and ecological stability of forest ecosystems. To that end, we examined the effect of a 40-year-long cultivation of Douglas fir (Pseudotsuga menziesii (Mirb Franco on the floristic composition, characteristics of the forest floor, physical and chemical properties of the soil and the intensity of organic matter decomposition in a beech forest in western Serbia (Mt. Maljen. It was found that the cultivation of Douglas fir caused a reduction in biodiversity, changes in the chemical properties of the soil, that were most pronounced in the surface layers (0-10 cm, and a slowing down in the metabolism of the beech stand. The absence of many plant species characteristic to natural beech forests was observed in the Douglas fir plantation, these were reflected in the detected changes in the chemical properties of the soil, such as lower substitutional acidity (p<0.05, depletion of the adsorption of basis in the cation complex (p<0.001 and lower amounts of C, N, P (p<0.001 and K (p<0.01 in relation to the beech stand (control. No differences were found in soil moisture and active acidity levels. The higher value of the C/N ratio of the Douglas fir litter (p<0.001 provided proof for its lower decomposition rate compared to beech litter (p<0.05. Over time, all these changes could lead to further acidification and degradation of the soil and a reduction in this ecosystem’s productivity.

  11. Carbon storage as affected by different site preparation techniques two years after mixed forest stand installation

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, F.; Figueiredo, T. de; Martins, A.

    2014-06-01

    Aim of study: This study aims at evaluating the impact of site preparation techniques prior to plantation on carbon storage and distribution in a young mixed stand of Pseudotsuga menziesii (PM) and Castanea sativa (CS). Area of study: The experimental field was established near Macedo de Cavaleiros, Northern Portugal, at 700 m elevation, mean annual temperature 12 degree centigrade and mean annual rainfall 678 mm. Material and methods: The experimental layout includes three replicates, where the different treatments corresponding to different tillage intensities were randomly distributed (high, moderate and slight intensity), in plots with an area of 375 m{sup 2} each. Twenty six months after forest stand installation, samples of herbaceous vegetation (0.49 m{sup 2} quadrat), forest species (8 PM and 8 CS) and mineral soil (at 0-5, 5-15, 15-30 and 30-60 cm depth) were collected in 15 randomly selected points in each treatment, processed in laboratory and analyzed for carbon by elemental carbon analyzer. Main results: The results obtained showed that: (i) more than 90% of the total carbon stored in the system is located in the soil, increasing in depth with tillage intensity; (ii) the contribution of herbaceous vegetation and related roots to the carbon storage is very low; (iii) the amount of carbon per tree is higher in CS than in PM; (iv) the global carbon storage was affected by soil tillage generally decreasing with the increase of tillage intensity. Accordingly, carbon storage capacity as affected by the application of different site preparation techniques should be a decision support tool in afforestation schemes. (Author)

  12. Carbon storage as affected by different site preparation techniques two years after mixed forest stand installation

    Directory of Open Access Journals (Sweden)

    Felicia Fonseca

    2014-04-01

    Full Text Available Aim of study: This study aims at evaluating the impact of site preparation techniques prior to plantation on carbon storage and distribution in a young mixed stand of Pseudotsuga menziesii (PM and Castanea sativa (CS. Area of study: The experimental field was established near Macedo de Cavaleiros, Northern Portugal, at 700 m elevation, mean annual temperature 12ºC and mean annual rainfall 678 mm. Material and Methods: The experimental layout includes three replicates, where the different treatments corresponding to different tillage intensities were randomly distributed (high, moderate and slight intensity, in plots with an area of 375 m2 each. Twenty six months after forest stand installation, samples of herbaceous vegetation (0.49 m2 quadrat, forest species (8 PM and 8 CS and mineral soil (at 0-5, 5-15, 15-30 and 30-60 cm depth were collected in 15 randomly selected points in each treatment, processed in laboratory and analyzed for carbon by elemental carbon analyzer. Main results: The results obtained showed that: (i more than 90% of the total carbon stored in the system is located in the soil, increasing in depth with tillage intensity; (ii the contribution of herbaceous vegetation and related roots to the carbon storage is very low; (iii the amount of carbon per tree is higher in CS than in PM; (iv the global carbon storage was affected by soil tillage generally decreasing with the increase of tillage intensity. Accordingly, carbon storage capacity as affected by the application of different site preparation techniques should be a decision support tool in afforestation schemes.Keywords: Site preparation; forest species; herbaceous vegetation; carbon storage; mineral soil; Portugal.

  13. Effect of environmental and cultural conditions on medium pH and explant growth performance of Douglas-fir (Pseudotsuga menziesii shoot cultures [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Chien-Chih Chen

    2015-05-01

    Full Text Available The medium pH level of plant tissue cultures has been shown to be essential to many aspects of explant development and growth. Sensitivity or tolerance of medium pH change in vitro varies according to specific requirements of individual species. The objectives of this study are to 1 determine medium pH change over time in storage conditions and with presence of explants, 2 evaluate the effects of medium pH change on explant growth performance and 3 assess the effects of adding a pH stabilizer, 2-(N-morpholinoethanesulfonic acid (MES that is commonly used in Douglas-fir micropropagation medium. Vegetative buds were collected in the spring before breaking dormancy from juvenile and mature donor trees for conducting these evaluations. Medium, with or without MES, was pre-adjusted to five pH levels before adding MES, agar and autoclaving. Medium pH changes and explant growth parameters were measured at eight different incubation times. Overall, MES provided a more stable medium pH, relative to starting pH values, under both light and dark storage conditions as well as with presence of explants. A general trend of decreasing medium pH over time was found comparing explants from juvenile and mature donor genotypes. Explant height and weight growth increased over time, but differ among explants from juvenile and mature donor genotypes. Our findings suggest that a 21-day subculture practice may best sustain medium freshness, medium pH level and desirable explant growth.

  14. Inter-specific competition in mixed forests of Douglas-fir (Pseudotsuga menziesii) and common beech (Fagus sylvatica) under climate change – a model-based analysis

    NARCIS (Netherlands)

    Reyer, C.; Lasch, P.; Mohren, G.M.J.; Sterck, F.J.

    2010-01-01

    Mixed forests feature competitive interactions of the contributing species which influence their response to environmental change. • We analyzed climate change effects on the inter-specific competition in a managed Douglas-fir/beech mixed forest. • Therefore, we initialised the process-based forest

  15. Transcriptome Changes in Douglas-fir (Pseudotsuga menziesii) Induced by Exposure to Diesel Emissions Generated with CeO2 Nanoparticle Fuel Additive

    Science.gov (United States)

    When cerium oxide nanoparticles are added to diesel fuel, fuel burning efficiency increases, producing emissions (DECe) with characteristics that differ from conventional diesel exhaust (DE). It has previously been shown that DECe induces more adverse pulmonary effects in rats on...

  16. Growth of Douglas-fir near equipment trails used for commercial thinning in the Oregon Coast Range.

    Science.gov (United States)

    Richard E. Miller; Jim Smith; Paul W. Adams; Harry W. Anderson

    2007-01-01

    Soil disturbance is a visually apparent result of using heavy equipment to harvest trees. Subsequent consequences for growth of remaining trees, however, are variable and seldom quantified. We measured tree growth 7 and 11 years after thinning of trees in four stands of coast Douglas-fir (Pseudotsuga menziesii var. menziesii(...

  17. Stand-Level Gas-Exchange Responses to Seasonal Drought in Very Young Versus Old Douglas-fir Forests of the Pacific Northwest, USA

    Energy Technology Data Exchange (ETDEWEB)

    Wharton, S; Schroeder, M; Bible, K; Falk, M; Paw U, K T

    2009-02-23

    This study examines how stand age affects ecosystem mass and energy exchange response to seasonal drought in three adjacent Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests. The sites include two early seral stands (ES) (0-15 years old) and an old-growth (OG) ({approx} 450-500) forest in the Wind River Experiment Forest, Washington, USA. We use eddy covariance flux measurements of carbon dioxide (F{sub NEE}), latent energy ({lambda}E) and sensible heat (H) to derive evapotranspiration rate (E{sub T}), bowen ratio ({beta}), water use efficiency (WUE), canopy conductance (G{sub c}), the Priestley-Taylor coefficient ({alpha}) and a canopy decoupling factor ({Omega}). The canopy and bulk parameters are examined to see how ecophysiological responses to water stress, including changes in available soil water ({theta}{sub r}) and vapor pressure deficit ({delta}e) differ among the two forest successional-stages. Despite very different rainfall patterns in 2006 and 2007, we observed distinct successional-stage relationships between E{sub T}, {alpha}, and G{sub c} to {delta}e and {theta}{sub r} during both years. The largest stand differences were (1) higher morning G{sub c} (> 10 mm s{sup -1}) at the OG forest coinciding with higher CO{sub 2} uptake (F{sub NEE} = -9 to -6 {micro}mol m{sup -2} s{sup -1}) but a strong negative response in G{sub c} to moderate {delta}e later in the day and a subsequent reduction in E{sub T}, and (2) higher E{sub T} at the ES stands because midday canopy conductance did not decrease until very low water availability levels (<30%) were reached at the end of the summer. Our results suggest that early seral stands are more likely than mature forests to experience declines in production if the summer drought becomes longer or intensifies because water conserving ecophysiological responses were only observed at the very end of the seasonal drought period in the youngest stands.

  18. Flight periodicity of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (Coleoptera: Curculionidae: Scolytinae) in Colorado, U.S.A

    Science.gov (United States)

    Jose F. Negron; Willis C. Schaupp; Lee Pederson

    2011-01-01

    There are about 500 species of bark beetles (Coleoptera: Curculionidae: Scolytinae) in the United States (Wood 1982). A number of them are important disturbance agents in forested ecosystems, occasionally creating large tracts of dead trees. One eruptive species is the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, which utilizes Douglas-fir, Pseudotsuga...

  19. Levels-of-growing-stock cooperative study in Douglas-fir: report no. 17—The Skykomish Study, 1961–93; The Clemons study, 1963–94.

    Science.gov (United States)

    James E. King; David D. Marshall; John F. Bell

    2002-01-01

    Stand treatments were completed as prescribed with an initial calibration cut and five thinnings resulting in eight new regimes for management of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Measurements were continued for an additional 14 years to observe stability and yields of stands in a postthinning holding period. Detailed descriptions...

  20. Drive Stands

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Systems Laboratory (ESL)houses numerous electrically driven drive stands. A drive stand consists of an electric motor driving a gearbox and a mounting...

  1. Variance in response of pole-size trees and seedlings of Douglas-fir and western hemlock to nitrogen and phosphorus fertilizers.

    Science.gov (United States)

    M.A. Radwan; J.S. Shumway; D.S. Debell; J.M. Kraft

    1991-01-01

    Three experiments were conducted to determine effects of N and P fertilizers on growth and levels of plant-tissue nutrients of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.). Both pole-size trees in closed-canopy stands and potted seedlings were use d . Soil series were...

  2. Effective height development of four co-occurring species in the gap-phase regeneration of Douglas fir monocultures under nature-oriented conversion. Forest Ecology and Management, Pages 189-198

    NARCIS (Netherlands)

    Dekker, M.; Breugel, van M.; Sterck, F.J.

    2007-01-01

    Natural regeneration in gaps in Douglas fir forest stands in the Netherlands mainly consists of Betula pendula (Roth.), Pinus sylvestris (L.), Larix kaempferi (Carr.), and Pseudotsuga menziesii (Mirb. Franco). Even though these species are well known, the autogenic development of these species in an

  3. Effect of thinning on form of young-growth Douglas-fir trees.

    Science.gov (United States)

    Vern P. Yerkes

    1960-01-01

    With the advent of increased thinning activity in managed stands of young-growth Douglas-fir (Pseudotsuga menziesii), knowledge of growth and form development of released trees becomes necessary for calculations of total volume and growth. Any appreciable change in the rate of radial increment at various points along the stem of a released tree...

  4. Do remnant old-growth trees accelerate rates of succession in mature Douglas-fir forests?

    Science.gov (United States)

    William S. Keeton; Jerry F. Franklin

    2005-01-01

    Biological legacies left by natural disturbances provide ecological functions throughout forest stand development, but their influences on processes of ecological succession are not completely understood. We investigated the successional role of one type of biological legacy: remnant old-growth trees persisting in mature Pseudotsuga menziesii (...

  5. ELEVATED CO2 AND ELEVATED TEMPERATURE HAVE NO EFFECT ON DOUGLAS-FIR FINE-ROOT DYNAMICS IN NITROGEN-POOR SOIL

    Science.gov (United States)

    Here, we investigate fine-root production, mortality and standing crop of Douglas-fir (Pseudotsuga menziesii) seedlings exposed to elevated atmospheric CO2 and elevated air temperature. We hypothesized that these treatments would increase fine-root production, but that mortality ...

  6. Growth and nutrition of Douglas fir, Scots pine and pedunculate oak in relation to soil acidification

    NARCIS (Netherlands)

    Visser, de P.H.B.

    1994-01-01

    In a Douglas fir ( Pseudotsuga menziesii (Mirb.) Franco) and in a Scots pine ( Pinus sylvestris L.) stand on sandy soil in the Netherlands, inputs of water, nutrients and acid loads were changed for four years. Effects of soil changes on growth and

  7. Douglas-fir tussock moth- and Douglas-fir beetle-caused mortality in a ponderosa pine/Douglas-fir forest in the Colorado Front Range, USA

    Science.gov (United States)

    Jose F. Negron; Ann M. Lynch; Willis C. Schaupp; Vladimir Bocharnikov

    2014-01-01

    An outbreak of the Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough, occurred in the South Platte River drainage on the Pike-San Isabel National Forest in the Colorado Front Range attacking Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. Stocking levels, species composition, and tree size in heavily and lightly defoliated stands were similar. Douglas-fir...

  8. Dynamic phenotypic plasticity in photosynthesis and biomass patterns in Douglas-fir seedlings

    Science.gov (United States)

    A. C. Koehn; G. I. McDonald; D. L. Turner; D. L. Adams

    2010-01-01

    As climate changes, understanding the mechanisms long-lived conifers use to adapt becomes more important. Light gradients within a forest stand vary constantly with the changes in climate, and the minimum light required for survival plays a major role in plant community dynamics. This study focuses on the dynamic plasticity of Douglas-fir (Pseudotsuga menziesii var....

  9. Simulating fuel treatment effects in dry forests of the western United States: testing the principles of a fire-safe forest

    Science.gov (United States)

    Morris C. Johnson; Maureen C Kennedy; David L. Peterson

    2011-01-01

    We used the Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS) to simulate fuel treatment effects on stands in low- to midelevation dry forests (e.g., ponderosa pine (Pinus ponderosa Dougl. ex. P. & C. Laws.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) of the western United States. We...

  10. Guide to fuel treatments in dry forests of the Western United States: assessing forest structure and fire hazard.

    Science.gov (United States)

    Morris C. Johnson; David L. Peterson; Crystal L. Raymond

    2007-01-01

    Guide to Fuel Treatments analyzes a range of fuel treatments for representative dry forest stands in the Western United States with overstories dominated by ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), and pinyon pine (Pinus edulis). Six silvicultural options (no thinning; thinning...

  11. Riparian microclimate and stream temperature: thinning and buffer-width influences

    Science.gov (United States)

    Paul D. Anderson

    2013-01-01

    Th inning of 30- to 70-year-old Douglas-fir (Pseudotsuga menziesii) stands is a common silvicultural activity on federal forest lands in Washington and Oregon west of the Cascade Range crest. Decreases in forest cover lead to alterations of site energy balances resulting in changes to understory and stream channel microclimates. Uncut vegetative...

  12. Multi-decadal establishment for single-cohort Douglas-fir forests

    Science.gov (United States)

    James A. Freund; Jerry F. Franklin; Andrew J. Larson; James A. Lutz

    2014-01-01

    The rate at which trees regenerate following stand-replacing wildfire is an important but poorly understood process in the multi-century development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests. Temporal patterns of Douglas-fir establishment reconstructed from old-growth forests (>450 year) have...

  13. Impact of the foliar pathogen Swiss needle cast on wood quality of Douglas-fir.

    Science.gov (United States)

    G.R. Johnson; Amy T. Grotta; Barbara L. Gartner; Geoff. Downes

    2005-01-01

    Many stands of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) near coastal areas of Oregon and Washington are heavily infected with the foliar pathogen causing Swiss needle cast (SNC) disease, and yet there is very little research on the resulting wood quality. Modulus of elasticity(MOE), modulus of rupture (MOR), microfibril angle (MFA), wood...

  14. Range-wide genetic variability in Pacific madrone (Arbutus menziesii): examining disease resistance, growth, and survival in a common garden study

    Science.gov (United States)

    Marianne Elliott; Gary A. Chastagner; Gil Dermott; Alan Kanaskie; Richard A. Sniezko; Jim. Hamlin

    2012-01-01

    Pacific madrone (Arbutus menziesii Pursh, Ericaceae) is an important evergreen hardwood species in Pacific Northwest (PNW) forests that provides food and habitat for wildlife and has high value in urban environments. Reeves (2007) indicates that Pacific madrone provides habitat for numerous wildlife species, especially cavity-nesting birds. Its...

  15. Silver fir and Douglas fir are more tolerant to extreme droughts than Norway spruce in south-western Germany

    Czech Academy of Sciences Publication Activity Database

    Vitali, V.; Büntgen, Ulf; Bauhus, J.

    2017-01-01

    Roč. 23, č. 12 (2017), s. 5108-5119 ISSN 1354-1013 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : temperate forest trees * picea-abies karst. * climate- change * water relations * vosges mountains * growth-patterns * species stands * scots pine * alba * productivity * Abies alba * Central Europe * climate change * dendroecology * drought tolerance * forest management * Picea abies * Pseudotsuga menziesii Subject RIV: EH - Ecology, Behaviour Impact factor: 8.502, year: 2016

  16. WestProPlus: a stochastic spreadsheet program for the management of all-aged Douglas-fir–hemlock forests in the Pacific Northwest.

    Science.gov (United States)

    Jingjing Liang; Joseph Buongiorno; Robert A. Monserud

    2006-01-01

    WestProPlus is an add-in program developed to work with Microsoft Excel to simulate the growth and management of all-aged Douglas-fir–western hemlock (Pseudotsuga menziesii (Mirb.) Franco–Tsuga heterophylla (Raf.) Sarg.) stands in Oregon and Washington. Its built-in growth model was calibrated from 2,706 permanent plots in the...

  17. Genecology of Douglas fir in western Oregon and Washington.

    Science.gov (United States)

    J. Bradley St Clair; Nancy L. Mandel; Kenneth W. Vance-Borland

    2005-01-01

    Background and Aims. Genecological knowledge is important for understanding evolutionary processes and for managing genetic resources. Previous studies of coastal Douglas fir (Pseudotsuga menziesii var. menziesii) have been inconclusive with respect to geographical patterns of variation, due in part to...

  18. Chapter 16 - Impacts of Swiss needle cast in the Cascade mountains of northern Oregon: Monitoring of permanent plots after 10 years (Project WC-EM-B-11-01)

    Science.gov (United States)

    Gregory M. Filip; Alan Kanaskie; Will R. Littke; John Browning; Kristen L. Chadwick; David C. Shaw; Robin L. Mulvey

    2014-01-01

    Swiss needle cast (SNC), caused by the fungus Phaeocryptopus gaeumannii, is one of the most damaging diseases of coast Douglasfir (Pseudotsuga menziesii var. menziesii) in the Pacific Northwest (Hansen and others 2000, Mainwaring and others 2005, Shaw and others 2011).

  19. Height-Related Trends in Leaf Xylem Anatomy and Shoot Hydraulic Characteristics in a Tall Conifer: Safety versus Efficiency in Water Transport

    National Research Council Canada - National Science Library

    D. R. Woodruff; F. C. Meinzer; B. Lachenbruch

    2008-01-01

    Hydraulic vulnerability of Douglas-fir (Pseudotsuga menziesii) branchlets decreases with height, allowing shoots at greater height to maintain hydraulic conductance at more negative leaf water potentials...

  20. Out-standing!

    DEFF Research Database (Denmark)

    Kural, René

    2013-01-01

    Out-standing concerns the Danish tennisplayer Leif Rovsing and his outstanding piece of architecture Danish Tennis Club in Hellerup.......Out-standing concerns the Danish tennisplayer Leif Rovsing and his outstanding piece of architecture Danish Tennis Club in Hellerup....

  1. Climate-Induced Mortality of Spruce Stands in Belarus

    Science.gov (United States)

    Kharuk, Viacheslav I.; Im, Sergei T.; Dvinskaya, Maria L.; Golukov, Alexei S.; Ranson, Kenneth J.

    2015-01-01

    The aim of this work is an analysis of the causes of spruce (Picea abies L.) decline and mortality in Belarus. The analysis was based on forest inventory and Landsat satellite (land cover classification, climate variables (air temperature, precipitation, evaporation, vapor pressure deficit, SPEI drought index)), and GRACE-derived soil moisture estimation (equivalent of water thickness anomalies, EWTA). We found a difference in spatial patterns between dead stands and all stands (i.e., before mortality). Dead stands were located preferentially on relief features with higher water stress risk (i.e., higher elevations, steeper slopes, south and southwestern exposure). Spruce mortality followed a series of repeated droughts between 1990 and 2010. Mortality was negatively correlated with air humidity (r = -0.52), and precipitation (r = -0.57), and positively correlated with the prior year vapor pressure deficit (r = 0.47), and drought increase (r = 0.57). Mortality increased with the increase in occurrence of spring frosts (r = 0.5), and decreased with an increase in winter cloud cover (r = -0.37). Spruce mortality was negatively correlated with snow water accumulation (r = -0.81) and previous year anomalies in water soil content (r = -0.8). Weakened by water stress, spruce stands were attacked by pests and phytopathogens. Overall, spruce mortality in Belarussian forests was caused by drought episodes and drought increase in synergy with pest and phytopathogen attacks. Vast Picea abies mortality in Belarus and adjacent areas of Russia and Eastern Europe is a result of low adaptation of that species to increased drought. This indicates the necessity of spruce replacement by drought-tolerant indigenous (e.g., Pinus sylvestris, Querqus robur) or introduced (e.g., Larix sp. or Pseudotsuga menzieslii) species to obtain sustainable forest growth management.

  2. MCOL, frontalin, and ethanol: A potential operational trap lure for Douglas-fir beetle in British Columbia

    Science.gov (United States)

    B. Staffan Lingren; Daniel R. Miller; J.P. LaFontaine

    2012-01-01

    The Douglas-fir beetle, Dedroctonus pseudotsugae (Coleoptera: Curculionidae) is a major pest of Douglas-fire, Pseudotsuga menziesii (Mirb.) in British Columbia (Humphreys 1995). An operational trap lure for D. pseudotsugae could be useful in an integrated pest management program to minimize mortality of Douglas-...

  3. Forest Stand Age

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Source data for forest stand age were obtained from the USDA Forest Inventory and Analysis (FIA) DataMart and were projected for future scenarios based on selected...

  4. Variable Attitude Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Variable Attitude Test Stand designed and built for testing of the V-22 tilt rotor aircraft propulsion system, is used to evaluate the effect of aircraft flight...

  5. Armillaria species in coniferous stands

    Directory of Open Access Journals (Sweden)

    Anna Żółciak

    2013-12-01

    Full Text Available Identification of the Armillaria species in selected coniferous stands (Scots pine stands, Norway spruce stands and fir stands was the aim of the work carried out on the basis of mating tests and consideration of macroscopic traits of fruit-bodies. One species of Armillaria [A. ostoyae (Romagnesi Herink] was found in Scots pine stands, three species [A. ostoyae, A. cepistipes Velenovský and A. borealis Marxmüller et Korhonen] were found in Norway spruce stands and two species [A. ostoyae and A. cepistipes] were found in fir stands.

  6. Principles of managing stands

    Science.gov (United States)

    David A. Marquis; Rodney Jacobs

    1989-01-01

    Forest stands are managed to achieve some combination of desired products or values. These products or values may include income and tangible benefits from timber production or fees for hunting rights and other recreational activities. The values may be intangible, such as the enjoyment of seeing wildlife or flowering plants, or the simple satisfaction of knowing that...

  7. STAND AT EASE

    African Journals Online (AJOL)

    Abel

    for what was described as “national service”. While books like these are not exactly flooding the shelves of bookstores, they roll of the presses more regularly now. These works mostly deal with ex-conscript's that actively experienced the war in. Namibia and Angola. Stand at ease is different: there is no "cordite and conflict".

  8. Economics of stand management

    Science.gov (United States)

    David K. Lewis

    1986-01-01

    This paper sets out to demonstrate the importance of considering the wealth represented by the growing stock in economic analyses of stand management alternatives, and to demonstrate the role of thinning in the manipulation of the efficiency of growing stock in the management of shortleaf pine (Pinus echinata Mill.). These goals are achieved through a demonstration of...

  9. Golden rule (standing theology)

    OpenAIRE

    Ellis, Randolph

    2017-01-01

    This study offers an example of ‘standing theology’ as distinguished from sitting theology or kneeling theology. The occasion was the Fourth Sunday of Easter in Bangor Cathedral, 2015. The Epistle reading was 1 John 3: 16–24.\\ud \\ud

  10. Multi-Purpose Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Multi-Purpose Test Stand is used for a wide variety of tests. The Stand is designed to be rotated through a range of fixed yaw positions to allow engines to be...

  11. Standing equine dental surgery.

    Science.gov (United States)

    Menzies, Robert A; Easley, Jack

    2014-04-01

    Dental surgeries refer to procedures that affect the dental tissues or their supporting structures. With the development of specific, efficacious, and conservative treatments, morbidity risks have been lowered and chances of benefiting the health of equids improved. Advances in quality of sedation, analgesia, and locoregional anesthesia allow a majority of dental surgeries to be performed in the standing patient. This update focuses on an orthograde endodontic technique, a minimally invasive buccotomy technique, with the potential to combine it with a transbuccal screw extraction technique, and revisits the AO pinless external fixator for fractures of the body of the mandible. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Standing Concertation Committee

    CERN Multimedia

    HR Department

    2009-01-01

    Ordinary Meeting on 11 May 2009 The meeting of the Standing Concertation Committee held on 11 May 2009 was entirely dedicated to the preparation of the TREF meeting on 19 & 20 May 2009. The Committee took note, discussed and agreed on some clarifications on a number of documents and presentations that the Management planned to submit and/or present to TREF on the following subjects: • Personnel statistics 2008: J. Purvis presented the Personnel Statistics for 2008 prepared by HR Department. In line with the previous year, key messages were firstly, a general reduction in staff (2544 to 2400, - 6%), secondly, a reduction in administrative services personnel (from 422 to 387, - 8%) and thirdly, a marked increase in the number of Users and Unpaid Associates (from 8369 to 9140, + 9%) • Five-Yearly Review 2010: A series of draft documents were submitted for discussion, comprising an introductory document explaining the statutory basis for the following four document...

  13. STANDING CONCERTATION COMMMITTEE

    CERN Multimedia

    HR Department

    2008-01-01

    ORDINARY MEETING ON 27 FEBRUARY 2008 The main items discussed at the meetings of the Standing Concertation Committee on 27 February 2008 included: Short-term Saved Leave Scheme The committee noted that, by the end of February 2008, some 600 staff had subscribed to the short-term saved leave scheme: approx 58% had subscribed 1 slice, 14% two slices, 5% three slices and 23% four slices. Administrative Circular No. 4 (Rev. 4) - Unemployment Insurance Scheme The committee agreed to recommend Administrative Circular No. 4 (Rev. 4) - Unemployment Insurance Scheme to the Director-General for approval. Administrative Circular No. 30 (Rev. 2) - Financial benefits upon taking up appointment and termination of contract The committee agreed to recommend Administrative Circular No. 30 (Rev. 2) - Financial Benefits upon taking up appointment and termination of contract to the Director-General for approval. Progressive Retirement Programme The Progressive Retirement Programme (PRP) was extended for a further year to 3...

  14. Standing Concertation Committee

    CERN Multimedia

    HR Department

    2008-01-01

    ORDINARY MEETING ON 27 FEBRUARY 2008 The main items discussed at the meetings of the Standing Concertation Committee on 27 February 2008 included: Short-term Saved Leave Scheme The Committee noted that, by the end of February 2008, some 600 staff had enrolled in the short-term saved leave scheme: approx. 58% had signed up for 1 slice, 14% for two slices, 5% for three slices and 23% for four slices. Administrative Circular No. 4 (Rev. 4) - Unemployment Insurance Scheme The Committee agreed to recommend the Director-General to approve Administrative Circular No. 4 (Rev. 4) - Unemployment Insurance Scheme. Administrative Circular No. 30 (Rev. 2) - Financial benefits upon taking up appointment and termination of contract The Committee agreed to recommend the Director-General to approve Administrative Circular No. 30 (Rev. 2) - Financial Benefits upon taking up appointment and termination of contract. Progressive Retirement Programme The Progressive Retirement Programme (PR...

  15. ISSP Position Stand

    DEFF Research Database (Denmark)

    Ryba, Tatiana; Stambulova, Natalia; Si, Gangyan

    2013-01-01

    but as relational and ␣uid; and (c) focusing on meaning (instead of cause) in cross-cultural and cultural research projects, and cultural praxis work. In the paper, we ␣rst provide an overview of the concepts of cultural competence and ethics of difference. Second, we present a step-by-step approach for developing...... a culturally competent project rooted either within cross-cultural or cultural research. Third, we focus on cultural praxis as a project that blends theory, research, and lived culture of practice. Finally, we summarize main points in nine postulates and provide recommendations for enhancing cultural......The multicultural landscape of contemporary sport sets a challenge to rethink sport and exercise psychology research and practice through a culturally re␣exive lens. This ISSP Position Stand provides a rigorous synthesis and engagement with existing scholarship to outline a roadmap for future work...

  16. Standing Concertation Commmittee

    CERN Multimedia

    HR Department

    2007-01-01

    Ordinary meeting on 2 november 2007 Extraordinary meeting on 12 November 2007 The main items discussed at the meetings of the Standing Concertation Committee on 2 November 2007 and 12 November included: Restaurants Supervisory Committee Report The committee took note of the report by the chairman of the Restaurants Supervisory Committee (RSC), T. Lagrange. In particular, it was recorded that, in Restaurant No. 1, the new kitchen and free flow arrangements had been inaugurated and all works had been commissioned on schedule in October 2007.The contractor, Novae, had taken over maintenance of the new kitchen. Some price increases were to be expected in the coming months due mainly to strong increases in the cost of basic ingredients. A problem with bad smells in the area of Restaurant No. 1 was being taken care of by tuning the ventilation system. The RSC wished to thank the management and staff of Restaurant No. 2 for their cooperation while Restaurant No 1 was ...

  17. Standing Concertation Committee

    CERN Multimedia

    HR Department

    2010-01-01

    Main issues examined at the meeting of 2 October 2009 The October 2009 meeting of the Standing Concertation Committee was entirely devoted to preparation of TREF’s meeting on 21-22 October. The Committee took note of, discussed and agreed on clarifications needed to some of the documents and presentations that the Management intended to submit and/or present to TREF on the following subjects: Equal opportunities The Committee took note of a preliminary report on equal opportunities at CERN drawn up by D. Chromek-Burckhart, the Equal Opportunities Officer, and T. Smith, Chairman of the Equal Opportunities Advisory Panel, containing in particular a proposal for a new process for resolving harassment conflicts. Technical analysis of the CERN Health Insurance Scheme - Actuary’s Report The Committee took note of a presentation by P. Charpentier, Chairman of the CERN Health Insurance Supervisory Board (CHIS Board), on the 2009 actuarial report on the CERN Health Insurance Scheme (CHIS). Th...

  18. Standing Concertation Committee

    CERN Multimedia

    HR Department

    2009-01-01

    The main items discussed at the meetings of the Standing Concertation Committee in the first quarter of 2009 included: Merit Appraisal and Recognition Scheme (MARS) 2009 exercise The committee took note of 2009 MARS ceiling guidelines giving the advancement budget by career path and amounting to approx 1.80% of the basic salary bill. To this will be added 250 steps CERN-wide, financed by savings from implementation of the international indemnity for 2007, 2008 and the first half of 2009. The specific Senior Staff Guidelines, including the proposed number of promotions from Career Path E to F, were also noted. The guidelines with respect to step distribution were also noted: the minima and maxima remain the same as in previous years. Compliance with the guidelines will continue to be monitored closely (more details, including a frequently asked questions section). It was also noted that Financial Awards (awards for extraordinary service and responsibility allowances) may b...

  19. NEEDLE ANATOMY CHANGES WITH INCREASING TREE AGE IN DOUGLAS FIR

    Science.gov (United States)

    Morphological differences between old growth and sapling (Pseudotsuga menziesii, (Mirb.) Franco) Douglas fir trees may extend to differences in needle anatomy. We used microscopy with image analysis to compare and quantify anatomical parameters in cross-sections of previous year...

  20. Standing concertation commmittee

    CERN Multimedia

    HR Department

    2009-01-01

    MEETINGS ON 2 AND 9 DECEMBER 2008 The main items discussed at the meetings of the Standing Concertation Committee on 2 and 9 December 2008 included: Medical Service Report 2007 The Committee took note of the report by Dr. E. Reymond (see http://sc-me.web.cern.ch/sc-me/fr/indexFR.htm) and of a number of points raised during the discussion. It was noted that the number of professional accidents declined in 2007 (361 accidents) in comparison with 2006 (483), as well as their gravity and frequency. The CERN Medical Service carried out a study on cancer prevalence (number of cases) and incidence (new cases per year per 100000 people), between 1993 and 2007, which identified some prostate, breast and colorectal cancers, though less than in the two Host States. Specific preventive actions will be promoted by the CERN CHISboard and the Medical Service in this context as well as in other areas. The committee expressed its thanks to all members of the Medical Service for their work i...

  1. Stand-up physics

    CERN Multimedia

    2009-01-01

    A CMS physicist and amateur stand up comic was named the winner of NESTA FameLab 2009. Tom Whyntie battled it out with nine others young scientists from across the UK to win the contest to find the country’s next top science communicator. Tom Whyntie with his prize money after the NESTA Famelab final.Tom Whyntie, who is currently doing his PhD on the CMS experiment, managed to persuade his supervisor to give him a few days off on 5 June so he could fly back to the UK for the final of NESTA FameLab 2009. In the competition, which has been dubbed ‘the X Factor for scientists’, he had just three minutes to explain a complex scientific idea to a panel of judges made up of high-profile science professionals. During the final, he captivated the audience with his talk about how finding nothing at the LHC, far from being a waste of £5 billion, would actually catalyse the next scientific revolution. It Whyntie’s own words: "If the L...

  2. Standing Concertation Commmittee

    CERN Document Server

    HR Department

    2007-01-01

    Ordinary meeting on 27 February 2007 The main items discussed at the meeting of the Standing Concertation Committee on 27 February 2007 included: Saved Leave Scheme (SLS): It was announced that a Management/Staff Association working group had been set up to discuss the Saved Leave Scheme (SLS): Members: M. Büttner, E. Chiaveri (chair), Ph. Defert, D. Klem, M. Vitasse, J.-M. Saint-Viteux. It was noted that the Staff Association was launching a questionnaire on SLS and distributed to all members of the personnel. Merit Recognition Guidelines : in the context of the new Merit Appraisal and Recognition Scheme (MARS), the committee took note of the CERN-wide 2007 Merit Recognition Guidelines, including the Frequently Asked Questions on HR Department's dedicated website. Information on CERN's medium and long-term plans (MTP-LTP)/Contract renewals/ External mobility The Committee took note of the information provided on CERN's MTP-LTP and of documentation distributed at the meeting by the Staff Associatio...

  3. Standing Concertation Committee

    CERN Multimedia

    HR Department

    2007-01-01

    ORDINARY MEETING ON 27 FEBRUARY 2007 The main items discussed at the meeting of the Standing Concertation Committee on 27 February 2007 included: Saved Leave Scheme (SLS): It was announced that a Management/Staff Association working group had been set up to discuss the Saved Leave Scheme (SLS): Members : M. Büttner, E. Chiaveri (chair), Ph. Defert, D. Klem, M. Vitasse, J.-M. Saint-Viteux. It was noted that the Staff Association was launching a questionnaire on SLS and distributed to all members of the personnel. Merit Recognition Guidelines: In the context of the new Merit Appraisal and Recognition Scheme (MARS), the committee took note of the CERN-wide 2007 Merit Recognition Guidelines, including the Frequently Asked Questions on HR Department's dedicated website. Information on CERN's medium and long-term plans (MTP-LTP)/Contract renewals/ External mobility The Committee took note of the information provided on CERN's MTP-LTP and of documentation distributed at the meeting by the Staff ...

  4. Standing Concertation Committee

    CERN Multimedia

    2007-01-01

    Ordinary meeting on 30 January 2007 The main items discussed at the meeting of the Standing Concertation Committee on 30 January 2007 included: Administrative Circular No. 26: with the introduction of the merit recognition system in the framework of the 5-yearly review of CERN employment conditions, Administrative Circular No. 26 has been revised. The committee took note of the revised document which is being finalized for submission to the Director-General for approval in the near future. Technical analysis of CERN Health Insurance Scheme: the Committee was informed that a group has been set up by the Director-General to analyse the financial situation of the CERN Health Insurance Scheme in the short and long term, and to propose measures to ensure that the Scheme remains in financial balance, with adequate cover, over the medium term. The group's terms of reference and membership were communicated. Voluntary programmes It was announced that the programmes: 'part-time work as a pre-retirement measure...

  5. Standing Concertation Committee

    CERN Multimedia

    2007-01-01

    ORDINARY MEETING ON 30 JANUARY 2007 The main items discussed at the meeting of the Standing Concertation Committee on 30 January 2007 included: Administrative Circular No. 26: with the introduction of the merit recognition system in the framework of the 5-yearly review of CERN employment conditions, Administrative Circular No. 26 has been revised. The Committee took note of the revised document which is being finalized for submission to the Director-General for approval in the near future. Technical analysis of CERN Health Insurance Scheme: the Committee was informed that a group has been set up by the Director-General to analyse the financial situation of the CERN Health Insurance Scheme in the short and long term, and to propose measures to ensure that the Scheme remains in financial balance, with adequate cover, over the medium term. The group's terms of reference and membership were communicated. Voluntary programmes It was announced that the programmes: 'part-time work as a pre-retirement mea...

  6. Dynamics of Connecticut hemlock stands

    Science.gov (United States)

    Jeffrey S. Ward; David M. Smith

    2000-01-01

    The stand dynamics and production of two one-acre plots of eastern hemlock (Tsuga canadensis L) in Connecticut have been followed for more than six decades. Data were recorded for all individual trees. One plot (Saltonstall) was established in 1924 after the removal of a hardwood overstory. This stand had a nearly pure, almost fully closed understory...

  7. A-1 Test Stand work

    Science.gov (United States)

    2010-01-01

    Employees at NASA's John C. Stennis Space Center work to maneuver a structural steam beam into place on the A-1 Test Stand on Jan. 13. The beam was one of several needed to form the thrust takeout structure that will support a new thrust measurement system being installed on the stand for future rocket engine testing. Once lifted onto the stand, the beams had to be hoisted into place through the center of the test stand, with only two inches of clearance on each side. The new thrust measurement system represents a state-of-the-art upgrade from the equipment installed more than 40 years ago when the test stand was first constructed.

  8. Is long primary growth associated with stem sinuosity in Douglas-fir?

    Science.gov (United States)

    Barbara L. Gartner; G.R. Johnson

    2006-01-01

    Stem sinuosity is a highly visible stem-form trait in the leaders of fast-growing Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) trees, yet its cause is unknown. We tested the hypotheses that sinuous stems have longer expanses of primary growth than nonsinuous stems (putting the leader at higher risk for...

  9. A SNP resource for douglas-fir: de novo transcriptome assembly and SNP detection and validation

    Science.gov (United States)

    Glenn R. Howe; Jianbin Yu; Brian Knaus; Richard Cronn; Scott Kolpak; Peter Dolan; W. Walter Lorenz; Jeffrey F.D. Dean

    2013-01-01

    Douglas-fir (Pseudotsuga menziesii), one of the most economically and ecologically important tree species in the world, also has one of the largest tree breeding programs. Although the coastal and interior varieties of Douglas-fir (vars. menziesii and glauco) are native to North America, the coastal variety is...

  10. Genetic variation in response to shade in coastal Douglas-fir.

    Science.gov (United States)

    J. Bradley St. Clair; Richard A. Sniezko

    1999-01-01

    Tree improvement programs have generally relied on testing families in open light environments. With increased interest in multiaged silvicultural systems, some people have questioned whether families selected in the open are appropriate for planting in the shade. We grew Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii...

  11. Effect of organic amendments on Douglas-fir transplants grown in fumigated versus non-fumigated soil

    Science.gov (United States)

    Nabil Khudduri

    2010-01-01

    We transplanted one-year old Douglas-fir (Pseudotsuga menziesii var. menziesii) seedlings into compost-amended soil that had either been spring-fumigated with a methyl bromide/chloropicrin combination or left unfumigated. Seedling nutrient, pathology, morphology, and packout measurements were significantly better for those transplanted into fumigated rather than non-...

  12. Genetic maladaptation of coastal Douglas-fir seedlings to future climates

    Science.gov (United States)

    Brad St. Clair;  Glenn T. Howe

    2007-01-01

    Climates are expected to warm considerably over the next century, resulting in expectations that plant populations will not be adapted to future climates.We estimated the risk of maladaptation of current populations of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) to future climates as the proportion of nonoverlap between two normal...

  13. Relative family performance and variance structure of open-pollinated Douglas-fir seedlings grown in three competitive environments.

    Science.gov (United States)

    J.B. St. Clair; W.T. Adams

    1991-01-01

    Open-pollinated Douglas-fir (Pseudotsuga menziesii var menziesii (Mirb.) Franco) families were tested in three contrasting competitive environments to test the hypothesis that relative performance as measured by total seedling dry weight is dependent upon distance or genotype of neighbors. The three competitive environments...

  14. DFSIM with economics: A financial analysis option for the DFSIM Douglas-fir simulator.

    Science.gov (United States)

    Roger O. Fight; Judith M. Chittester; Gary W. Clendenen

    1984-01-01

    A modified version of the DFSIM Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) growth and yield simulator, DFSIM WITH ECONOMICS, now has an economics option that allows the user to estimate present net worth at the same time a silvicultural regime is simulated. If desired, the economics option will apply a...

  15. Ammonium nitrate, urea, and biuret fertilizers increase volume growth of 57-year-old Douglas-fir trees within a gradient of nitrogen deficiency.

    Science.gov (United States)

    Richard E. Miller; Donald L. Reukema; John W. Hazard

    1996-01-01

    In a nitrogen-deficient plantation in southwest Washington, we (1) compared effects of 224 kg N/ha as ammonium nitrate, urea, and biuret on volume growth of dominant and codominant Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco); (2) determined how 8-year response of these trees to fertilization was related to...

  16. Detecting response of Douglas-fir plantations to urea fertilizer at three locations in the Oregon Coast Range.

    Science.gov (United States)

    Richard E. Miller; Jim Smith; Harry. Anderson

    2001-01-01

    Fertilizer trials in coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) in the Oregon Coast Range usually indicate small and statistically nonsignificant response to nitrogen (N) fertilizers. Inherently weak experimental designs of past trials could make them too insensitive to detect growth differences...

  17. Estimating tree biomass, carbon, and nitrogen in two vegetation control treatments in an 11-year-old Douglas-fir plantation on a highly productive site

    Science.gov (United States)

    Warren D. Devine; Paul W. Footen; Robert B. Harrison; Thomas A. Terry; Constance A. Harrington; Scott M. Holub; Peter J. Gould

    2013-01-01

    We sampled trees grown with and without competing vegetation control in an 11-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) plantation on a highly productive site in southwestern Washington to create diameter based allometric equations for estimating individual-tree bole, branch, foliar, and total...

  18. Genetic variation in tree structure and its relation to size in Douglas-fir: I. Biomass partitioning, foliage efficiency, stem form, and wood density.

    Science.gov (United States)

    J.B. St. Clair

    1994-01-01

    Genetic variation and covariation among traits of tree size and structure were assessed in an 18-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) genetic test in the Coast Range of Oregon. Considerable genetic variation was found in size, biomass partitioning, and wood density, and genetic gains may be...

  19. Realized gains from block-plot coastal Douglas-fir trials in the northern Oregon Cascades

    Science.gov (United States)

    Terrence Z. Ye; Keith J.S. Jayawickrama; J. Bradley. St. Clair

    2010-01-01

    Realized gains for coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) were evaluated using data collected from 15-year-old trees from five field trials planted in large block plots in the northern Oregon Cascades. Three populations with different genetic levels (elite--high predicted gain; intermediate--moderate predicted gain; and an...

  20. Residual Liquefaction under Standing Waves

    DEFF Research Database (Denmark)

    Kirca, V.S. Ozgur; Sumer, B. Mutlu; Fredsøe, Jørgen

    2012-01-01

    This paper summarizes the results of an experimental study which deals with the residual liquefaction of seabed under standing waves. It is shown that the seabed liquefaction under standing waves, although qualitatively similar, exhibits features different from that caused by progressive waves....... The experimental results show that the buildup of pore-water pressure and the resulting liquefaction first starts at the nodal section and spreads towards the antinodal section. The number of waves to cause liquefaction at the nodal section appears to be equal to that experienced in progressive waves for the same...... wave height. Recommendations are made as to how to assess liquefaction potential in standing waves. Copyright © 2012 by the International Society of Offshore and Polar Engineers (ISOPE)....

  1. User's Guide to the Stand Prognosis Model

    Science.gov (United States)

    William R. Wykoff; Nicholas L. Crookston; Albert R. Stage

    1982-01-01

    The Stand Prognosis Model is a computer program that projects the development of forest stands in the Northern Rocky Mountains. Thinning options allow for simulation of a variety of management strategies. Input consists of a stand inventory, including sample tree records, and a set of option selection instructions. Output includes data normally found in stand, stock,...

  2. Stocking, growth, and yield of oak stands

    Science.gov (United States)

    Samuel F. Gingrich

    1971-01-01

    An appraisal of stocking in even-aged upland oak stands is a prerequisite for determining the cultural needs of a given stand. Most oak stands have sufficient stocking to utilize the site, but are deficient in high-quality trees. Thinning such stands offers a good opportunity to upgrade the relative quality of the growing stock and enhance the growth and yield...

  3. An Induction Linac Test Stand

    CERN Document Server

    De Hope, William; Kihara, Ron; Ong, Mike; Vogtlin, George; Zentler, Jan-Mark

    2005-01-01

    A single-cell test stand has been constructed to facilitate study and guide improvements of the induction electron linac at the FXR radiographic facility at LLNL.* This paper will discuss how modifications in pulse compression and shaping, pulse power transmission, initial ferrite state, and accelerator cell loading have been performed on the test stand and can be applied to the entire accelerator. Some of the specialized diagnostics being used will be described. Finally, the paper will discuss how computer modeling and judicious timing control can be used to optimize accelerator performance by making only selective changes that can be accomplished at minimal cost.

  4. Students dance longitudinal standing waves

    Science.gov (United States)

    Ruiz, Michael J.

    2017-05-01

    A demonstration is presented that involves students dancing longitudinal standing waves. The resulting kinaesthetic experience and visualization both contribute towards an understanding of the natural modes of vibrations in open and closed pipes. A video of this fun classroom activity is provided (http://mjtruiz.com/ped/dance/).

  5. A3 TEST STAND CONSTRUCTION

    Science.gov (United States)

    2008-01-01

    THIS IMAGE SHOWS THE DEVELOPMENT AND CONSTRUCTION OF THE A3 TEST STAND IN SUPPORT OF THE ARES/CLV UPPER STAGE ENGINE AT STENNIS SPACE CENTER, MISSISSIPPI. THIS IMAGE IS EXTRACTED FROM A HIGH DEFINITION VIDEO FILE AND IS THE HIGHEST RESOLUTION AVAILABLE.

  6. Silvicultural treatments in immature stands

    Science.gov (United States)

    Richard C. Schlesinger

    1989-01-01

    Silvicultural treatments for immature central hardwood stands include precommercial and commercial thinnings, lateral branch pruning, fertilization, cull tree deadening, and vine removal. The specifics of these treatments are discussed elsewhere in these Notes. This Note discusses some basic concepts in the selection and application of silvicultural treatments for...

  7. Burnout : de stand van zaken

    NARCIS (Netherlands)

    Taris, T.; Houtman, I.L.D.; Schaufeli, W.

    2013-01-01

    Dit artikel geeft een overzicht van de stand van zaken in het onderzoek naar burnout. Burnout is een syndroom van extreme vermoeidheid (uitputting), afstand nemen van het werk (distantie) en weinig vertrouwen in het eigen kunnen (verminderde competentie), waarbij de oorzaken voor deze aspecten

  8. Prognosis model for stand development

    Science.gov (United States)

    Albert R. Stage

    1973-01-01

    Describes a set of computer programs for developing prognoses of the development of existing stand under alternative regimes of management. Calibration techniques, modeling procedures, and a procedure for including stochastic variation are described. Implementation of the system for lodgepole pine, including assessment of losses attributed to an infestation of mountain...

  9. Crown management and stand density

    Science.gov (United States)

    Thomas J. Dean; V. Clark Baldwin

    1996-01-01

    Determination of optimal stand-density continues to be a difficult problem. A trial cannot be established on every combination of soils, topography, and climate possible across the range of a widely distributed species such as loblolly pine, and continual advancements in nutrition and vegetation management, breeding, and utilization make established trials obsolete....

  10. Density, ages, and growth rates in old-growth and young-growth forests in coastal Oregon

    Science.gov (United States)

    Tappeiner, J. C.; Huffman, D.; Spies, T.; Bailey, John D.

    1997-01-01

    We studied the ages and diameter growth rates of trees in former Douglas-fir (Pseudotsuga menziesii (Mirb.)Franco) old-growth stands on 10 sites and compared them with young-growth stands (50-70 years old, regenerated after timber harvest) in the Coast Range of western Oregon. The diameters and diameter growth rates for the first 100 years of trees in the old-growth stands were significantly greater than those in the young-growth stands. Growth rates in the old stands were comparable with those from long-term studies of young stands in which density is about 100-120 trees/ha; often young-growth stand density is well over 500 trees/ha. Ages of large trees in the old stands ranged from 100 to 420 years; ages in young stands varied by only about 5 to 10 years. Apparently, regeneration of old-growth stands on these sites occurred over a prolonged period, and trees grew at low density with little self-thinning; in contrast, after timber harvest, young stands may develop with high density of trees with similar ages and considerable self-thinning. The results suggest that thinning may be needed in dense young stands where the management objective is to speed development of old-growth characteristics.

  11. Transpalpebral eye enucleation in the standing horse

    DEFF Research Database (Denmark)

    Christophersen, Mogens Teken

    Transpalpebral eye enucleation in the standing horse. The Nordic Equine Veterinary Conference, Proceedings, Copenhagen. Denmark. Nov. 2011.......Transpalpebral eye enucleation in the standing horse. The Nordic Equine Veterinary Conference, Proceedings, Copenhagen. Denmark. Nov. 2011....

  12. 21 CFR 203.35 - Standing requests.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Standing requests. 203.35 Section 203.35 Food and... PRESCRIPTION DRUG MARKETING Samples § 203.35 Standing requests. Manufacturers or authorized distributors of record shall not distribute drug samples on the basis of open-ended or standing requests, but shall...

  13. The interactive impact of forest site and stand attributes and logging technology on stand management

    Science.gov (United States)

    C.B. LeDoux; J.E. Baumgras

    1991-01-01

    The impact of selected site and stand attributes on stand management is demonstrated using actual forest model plot data and a complete systems simulation model called MANAGE. The influence of terrain on the type of logging technology required to log a stand and the resulting impact on stand management is also illustrated. The results can be used by managers and...

  14. The one-leg standing radiograph

    OpenAIRE

    Pinsornsak, P.; Naratrikun, K.; Kanitnate, S.; Sangkomkamhang, T.

    2016-01-01

    Objectives The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Methods Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis wa...

  15. Consistent definition and application of Reineke's Stand Density Index in silviculture and stand projection

    Science.gov (United States)

    John D. Shaw; James N. Long

    2010-01-01

    Reineke’s Stand Density Index (SDI) has been available to silviculturists for over 75 years, but application of this stand metric has been inconsistent. Originally described as a measurement of relative density in single-species, even-aged stands, it has since been generalized for use in uneven-aged stands and mixed-species stands. However, methods used to establish...

  16. Thinning in artificially regenerated young beech stands

    Directory of Open Access Journals (Sweden)

    Novák Jiří

    2015-12-01

    Full Text Available Although beech stands are usually regenerated naturally, an area of up to 5,000 ha year−1 is artificially regenerated by beech in the Czech Republic annually. Unfortunately, these stands often showed insufficient stand density and, consequently, lower quality of stems. Therefore, thinning methods developed for naturally regenerated beech stands are applicable with difficulties. The paper evaluates the data from two thinning experiments established in young artificially regenerated beech stands located in different growing conditions. In both experiments, thinning resulted in the lower amount of salvage cut in following years. Positive effect of thinning on periodic stand basal area increment and on periodic diameter increment of dominant trees was found in the beech stand located at middle elevations. On the other hand, thinning effects in mountain conditions were negligible. Thinning focusing on future stand quality cannot be commonly applied in artificially regenerated beech stands because of their worse initial quality and lower density. However, these stands show good growth and response to thinning, hence their management can be focused on maximising beech wood production.

  17. The one-leg standing radiograph

    Science.gov (United States)

    Naratrikun, K.; Kanitnate, S.; Sangkomkamhang, T.

    2016-01-01

    Objectives The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Methods Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis was evaluated using the joint space width and Kellgren-Lawrence (KL) radiographic classification. The t-test was used for statistical analysis. Results The mean medial joint space width found in the one-leg and in the both-legs standing view were measured at 1.8 mm and 2.4 mm, respectively (p leg standing views, respectively. No changes for KL IV osteoarthritis diagnoses have been found between both- and one-leg standing views. Conclusions One-leg standing radiographs better represent joint space width than both-legs standing radiographs. 32% of both-legs standing radiographs have changed the KL grading to a more severe grade than that in the one-leg standing radiographs. Cite this article: P. Pinsornsak, K. Naratrikun, S. Kanitnate, T. Sangkomkamhang. The one-leg standing radiograph: An improved technique to evaluate the severity of knee osteoarthritis. Bone Joint Res 2016;5:436–441. DOI: 10.1302/2046-3758.59.BJR-2016-0049.R1. PMID:27683299

  18. Reineke’s stand density index: a quantitative and non-unitless measure of stand density

    Science.gov (United States)

    Curtis L. VanderSchaaf

    2013-01-01

    When used as a measure of relative density, Reineke’s stand density index (SDI) can be made unitless by relating the current SDI to a standard density but when used as a quantitative measure of stand density SDI is not unitless. Reineke’s SDI relates the current stand density to an equivalent number of trees per unit area in a stand with a quadratic mean diameter (Dq)...

  19. Development of a stand density index equation for slash pine stands

    Science.gov (United States)

    Paul F. Doruska

    2002-01-01

    Stand density index (SDI) is commonly used as the basis for density management guides for even-aged forest stands. Many tree species follow the same self-thinning trajectory, allowing for the use of stand density index in such guides. Slash pine (Pinus elliottii Englem.) has been shown to depart from the self-thinning trajectory exhibited by other...

  20. SPEED ROLLER STAND MEASUREMENT SYSTEM CHECKING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Y. Zybtsev

    2011-01-01

    Full Text Available The study has shown that the accuracy of brakes checking by inertial stands depends upon the applied methods of measurement of braking parameters (stand slowing down, braking distance, brakes triggering time, current speed as well as the methods of metrological checking of measuring system canals.

  1. Design Difficulties in Stand Density Studies

    Science.gov (United States)

    Frank A. Bennett

    1969-01-01

    Designing unbiased stand density studies is difficult. An acceptable sample requires stratification of the plots of age, site, and density. When basal area, percent stocking, or Reineke's stand density index is used as the density measure, this stratification forces a high negative correlation between site and number of trees per acre. Mortality in trees per acre...

  2. Steady as a rock: Biogeomorphic influence of nurse rocks and slope processes on kūpaoa (Dubautia menziesii) shrubs in Haleakalā Crater (Maui, Hawai'i)

    Science.gov (United States)

    Pérez, Francisco L.

    2017-10-01

    This study examines biogeomorphic interactions between nurse rocks, slope processes, and 300 kūpaoa (Dubautia menziesii) shrubs in Haleakalā Crater (Maui, Hawai'i). Research objectives were to: assess the association of kūpaoa with substrates upslope and downslope of plants, and proximity to the closest rock uphill; contrast shrub/substrate relationships with site frequency of sediment types; measure surface soil shear-strength and compressibility on 50 paired locations near boulders; and investigate the aggregation characteristics and spatial patterns of kūpaoa in relation to rock and substrate variation. Data analyzed came from three 100-plant surveys at 3 sites: a plant census at 2720-2975 m altitude, and wandering-quarter transects (WQTs) across two areas (2610-2710 m); ground sediment cover was estimated along four phototransects on these sites. Data for the three 100-plant surveys included substrate type-outcrops, blocks, cobbles, pebbles, exposed soil, organic litter-upslope from each plant, and distance to the largest rock upslope. The two surveys examined along WQTs included substrate type found downslope from kūpaoa, plant height, plant diameters across and along the slope, and distance between successively censused plants. Most plants grew downslope of nurse rocks; > 74% were adjacent to blocks or outcrops, and > 17% near cobbles. Plants showed avoidance for finer substrates; only 5.3% and 2.7% grew on/near bare soils and pebbles, respectively. About 92% of kūpaoa were ≤ 10 cm downslope of rocks; > 89% grew ≤ 2 cm away, and 83% in direct contact with a rock. Some seedlings also grew on pukiawe (Leptecophylla tameiameiae) nurse plants. Several stable rock microsites protected plants from disturbance by slope processes causing debris shift. Site sediments were significantly finer than substrates near plants; shrubs grew preferentially adjacent to boulders > 20 cm wide, which were more common near plants than across sites. Soils downslope of 50

  3. Climate Drives Episodic Conifer Establishment after Fire in Dry Ponderosa Pine Forests of the Colorado Front Range, USA

    Directory of Open Access Journals (Sweden)

    Monica T. Rother

    2017-05-01

    Full Text Available In recent years, warming climate and increased fire activity have raised concern about post-fire recovery of western U.S. forests. We assessed relationships between climate variability and tree establishment after fire in dry ponderosa pine forests of the Colorado Front Range. We harvested and aged over 400 post-fire juvenile ponderosa pine (Pinus ponderosa and Douglas-fir (Pseudotsuga menziesii trees using an improved tree-ring based approach that yielded annually-resolved dates and then assessed relationships between climate variability and pulses of tree establishment. We found that tree establishment was largely concentrated in years of above-average moisture availability in the growing season, including higher amounts of precipitation and more positive values of the Palmer Drought Severity Index. Under continued climate change, drier conditions associated with warming temperatures may limit forest recovery after fire, which could result in lower stand densities or shifts to non-forested vegetation in some areas.

  4. Studies on the occurrence and colonisation of plants by Phytophthora ramorum in Poland

    Directory of Open Access Journals (Sweden)

    Leszek Orlikowski

    2014-08-01

    Full Text Available Occurrence of Phytophthora ramorum on Rhododendron, Vaccinium, Viburnum and Quercus species in ornamental nurseris and fores stands in 2001-2002 and necrosis spead on plant parts and seedlings wewe studied. Only P. citricola was isolated from Rhododendron spp. and V.vitis-idaea. Shoot necrosis and dieback symptoms were not observed on Viburnum species in surveyed nurseries. From diseased Quercus trunks among others Armillaria spp. and Fusarium spp. were isolated. Inoculation of leaves and stem parts of Rhododendron cultivars and other ericaceous plants with P. ramorum resulted in the development of leaf and stem rot. The species caused stem necrosis of Fagus sylvatica, Q. rubra and Pseudotsuga menziesii but symptoms developed slowly.

  5. Effects of biotic and abiotic factors on resistance versus resilience of Douglas fir to drought.

    Science.gov (United States)

    Carnwath, Gunnar; Nelson, Cara

    2017-01-01

    Significant increases in tree mortality due to drought-induced physiological stress have been documented worldwide. This trend is likely to continue with increased frequency and severity of extreme drought events in the future. Therefore, understanding the factors that influence variability in drought responses among trees will be critical to predicting ecosystem responses to climate change and developing effective management actions. In this study, we used hierarchical mixed-effects models to analyze drought responses of Pseudotsuga menziesii in 20 unmanaged forests stands across a broad range of environmental conditions in northeastern Washington, USA. We aimed to 1) identify the biotic and abiotic attributes most closely associated with the responses of individual trees to drought and 2) quantify the variability in drought responses at different spatial scales. We found that growth rates and competition for resources significantly affected resistance to a severe drought event in 2001: slow-growing trees and trees growing in subordinate canopy positions and/or with more neighbors suffered greater declines in radial growth during the drought event. In contrast, the ability of a tree to return to normal growth when climatic conditions improved (resilience) was unaffected by competition or relative growth rates. Drought responses were significantly influenced by tree age: older trees were more resistant but less resilient than younger trees. Finally, we found differences between resistance and resilience in spatial scale: a significant proportion (approximately 50%) of the variability in drought resistance across the study area was at broad spatial scales (i.e. among different forest types), most likely due to differences in the total amount of precipitation received at different elevations; in contrast, variation in resilience was overwhelmingly (82%) at the level of individual trees within stands and there was no difference in drought resilience among forest types

  6. Basic Stand Alone Medicare Outpatient Procedures PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Outpatient Procedures Public Use Files (PUF) with information from Medicare outpatient claims. The CMS BSA...

  7. RLC Forest Stand Carbon Map of Russia

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This dataset is a 1:15 million scale map of forest stand carbon for the land area of Russia (Stone et al., 2000). The objective was to create a first...

  8. RLC Forest Stand Carbon Map of Russia

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset is a 1:15 million scale map of forest stand carbon for the land area of Russia (Stone et al., 2000). The objective was to create a first approximation...

  9. Minnesota DNR Forest Stand Inventory Version 2

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer is a digital inventory of individual forest stands. The data is collected by DNR Foresters in each DNR Forestry Administrative Area, and is updated on a...

  10. 1990 sampling of treated aspen stands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In mid-August, 1990, sampling of aspen stand exclosures were conducted at the National Elk Refuge. This sampling is part of a study to monitor aspen regeneration on...

  11. Basic Stand Alone Carrier Line Items PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Carrier Line Items Public Use Files (PUF) with information from Medicare Carrier claims. The CMS BSA Carrier Line...

  12. Steel erected at A-3 Test Stand

    Science.gov (United States)

    2008-01-01

    Workers erect the first fabricated steel girders to arrive at the A-3 Test Stand at Stennis Space Center. Steel work began at the construction site Oct. 29 and is scheduled to continue into next spring.

  13. Species composition of developing Central Appalachian hardwood stands following clearcutting

    Science.gov (United States)

    Lance A. Vickers; Thomas Fox

    2015-01-01

    This study examined the species composition of 47 paired stands on submesic sites on the Appalachian Plateau of West Virginia. Paired stands consisted of a mature stand adjacent to a young clearcut that was

  14. Stand and within-stand factors influencing Golden-winged Warbler use of regenerating stands in the central Appalachian Mountains

    Directory of Open Access Journals (Sweden)

    Marja H. Bakermans

    2015-06-01

    Full Text Available The Golden-winged Warbler (Vermivora chrysoptera is currently being considered for protected status under the U.S. Endangered Species Act. The creation of breeding habitat in the Appalachian Mountains is considered a conservation priority for this songbird, which is dependent on extensively forested landscapes with adequate availability of young forest. We modeled abundance of Golden-winged Warbler males in regenerating harvested forest stands that were 0-17 years postharvest at both mid-Appalachian and northeast Pennsylvania regional scales using stand and within-stand characteristics of 222 regenerating stands, 2010-2011. Variables that were most influential at the mid-Appalachian scale were different than those in the northeast region. Across the mid-Appalachian ecoregion, the proportion of young forest cover, i.e., shrub/scrub cover, within 1 km of regenerating stands best explained abundance of Golden-winged Warblers. Golden-winged Warbler response was best explained by a concave quadratic relationship in which abundance was highest with 5-15% land in young forest cover. We also found evidence that the amount of herbaceous cover, i.e., the amount of grasses and forbs, within a regenerating stand positively influenced abundance of Golden-winged Warblers. In northeastern Pennsylvania, where young forest cover is found in high proportions, the distance to the nearest regenerating stand best explained variation in abundance of Golden-winged Warblers. Abundance of Golden-winged Warblers was 1500 m away. When modeling within-stand features in the northeast region, many of the models were closely ranked, indicating that multiple variables likely explained Golden-winged Warbler response to within-stand conditions. Based on our findings, we have proposed several management guidelines for land managers interested in creating breeding habitat for Golden-winged Warblers using commercial timber operations. For example, we recommend when managing for

  15. Laboratory Stands for Wideband Analysis Radiocommunication Signals

    OpenAIRE

    Studanski, Ryszard; Was, Radosław; Studanska, Agnieszka; Garus, Jarosław

    2012-01-01

    A laboratory stand for wideband analysis radiocommunication signals is presented in the paper. The stand is designed for signals acquisition in wide spectrum and research a field of digital signal processing. Procedures used for simultaneous acquiring many frequency channels in selected wide band are described. The method of detection of direct sequence spread spectrum signals (DS SS) which power spectral density is lower than noise is also discussed. Executed research were performed with sig...

  16. Birch Stands Growth Increase in Western Siberia

    Science.gov (United States)

    Kharuk, Viacheslav I.; Kuzmichev, Valeriy V.; Im, Sergey T.; Ranson, Kenneth J.

    2014-01-01

    Birch (Betula pendula Roth) growth within the Western Siberia forest-steppe was analyzed based on long-term (1897-2006) inventory data (height, diameter at breast height [dbh], and stand volume). Analysis of biometry parameters showed increased growth at the beginning of twenty-first century compared to similar stands (stands age = 40-60 years) at the end of nineteenth century. Mean height, dbh, and stem volume increased from 14 to 20 m, from 16 to 22 cm, and from approx. 63 to approx. 220 cu m/ha, respectively. Significant correlations were found between the stands mean height, dbh, and volume on the one hand, and vegetation period length (r(sub s) = 0.71 to 0.74), atmospheric CO2 concentration (r(sub s) = 0.71 to 0.76), and drought index (Standardized Precipitation-Evapotranspiration Index, r(sub s) = -0.33 to -0.51) on the other hand. The results obtained have revealed apparent climate-induced impacts (e.g. increase of vegetation period length and birch habitat drying due to drought increase) on the stands growth. Along with this, a high correlation of birch biometric parameters and [CO2] in ambient air indicated an effect of CO2 fertilization. Meanwhile, further drought increase may switch birch stand growth into decline and greater mortality as has already been observed within the Trans-Baikal forest-steppe ecotone.

  17. Yield tables for Italian coppice stands

    Energy Technology Data Exchange (ETDEWEB)

    Bernetti, G.

    1980-01-01

    A critical review of results from 32 yield tables for Italian coppice stands. Particular attention is paid to age of maximum m.a.i., distribution of total volume of fuelwood up to 3 cm in diameter and of brushwood, and relation between mean height and volume. A provisional general yield table is given for Quercus cerris and mixed deciduous coppice stands, based on data from 12 local tables. Maximum m.a.i. occurs relatively early, with rather low values. For Quercus ilex and mixed evergreen broadleaved coppice stands on the coast of Tuscany, tables perpared separately by Giordano and Patrone are broadly in agreement. In terms of total volume, the evergreen coppice stands of the Mediterranean maquis have a higher yield than deciduous coppice stands, and contain a higher % of brushwood. Data for Fagus sylvatica are somewhat incomplete, but m.a.i. for fuelwood appears to remain constant between the ages of 12 and 24, with maximum values of 5 and 2.1 cu.m/ha for the best and poorest quality classes respectively. Castanea sativa coppice stands can show very high rates of increment e.g. maximum m.a.i. of 20 cu.m/ha on highly fertile volcanic soils.

  18. Standing on a declining surface reduces transient prolonged standing induced low back pain development.

    Science.gov (United States)

    Gallagher, Kaitlin M; Callaghan, Jack P

    2016-09-01

    While alternating standing position on a sloped surface has proven successful at reducing low back pain during standing, the purpose of this study was to evaluate standing solely on a declining surface to isolate the influence of the postural change. Seventeen participants performed two 75-min prolonged standing occupational simulations- level ground and declining surface. Fifty-three percent of participants (9/17) were categorized as pain developers during the level ground standing condition. For these same pain developers, their average maximum pain scores were 58% lower during sloped standing. All participants showed greater hip flexion, trunk-to-thigh angle flexion, and posterior translation of the trunk center of gravity when standing on the sloped surface. These postural changes could cause the muscles crossing the hip posteriorly to increase passive stiffness and assist with stabilizing the pelvis. This study stresses the importance of hip kinematics, not just lumbar spine posture, in reducing prolonged standing induced low back pain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Advance reproduction and other stand characteristics in Pennsylvania and French stands of northern red oak

    Science.gov (United States)

    Kim C. Steiner; Marc D. Abrams; Todd W. Bowersox

    1993-01-01

    The frequent scarcity of northern red oak (NRO) advance reproduction raises questions about its regeneration potential under prevailing stand conditions in eastern North America. In contrast, NRO plantations in France typically contain abundant advance reproduction. The purpose of this study was to document stand conditions in Pennsylvania (PA) and southwestern France...

  20. Model for multi-stand management based on structural attributes of individual stands

    Science.gov (United States)

    G.W. Miller; J. Sullivan

    1997-01-01

    A growing interest in managing forest ecosystems calls for decision models that take into account attribute goals for large forest areas while continuing to recognize the individual stand as a basic unit of forest management. A dynamic, nonlinear forest management model is described that schedules silvicultural treatments for individual stands that are linked by multi-...

  1. Static standing, dynamic standing and spasticity in individuals with spinal cord injury.

    Science.gov (United States)

    Sadeghi, M; Mclvor, J; Finlayson, H; Sawatzky, B

    2016-05-01

    This was a cross-over efficacy study design. To determine spasticity differences between static and dynamic standing training in individuals with spinal cord injury (SCI). Vancouver, Canada. Ten individuals with SCI who could stand with or without bracing or supports participated in both dynamic and static standing training (one session each, 2 days apart) using a Segway. The primary outcome was spasticity as measured by Visual Analog Scale (VAS), Modified Ashworth Scale (MAS) and electromyography (EMG) of the quadriceps, hamstrings, adductors and gastrocnemius. There was no statistically detectable difference in spasticity between dynamic and static standing training in individuals with SCI as measured by VAS, MAS or EMG, although there was a trend towards decreased spasticity after the dynamic training. There is no significant difference in spasticity outcomes between static and dynamic standing training on a Segway for individuals with SCI. This research was funded by Natural Sciences and Engineering Research Council of Canada and International Collaboration on Repair Discoveries.

  2. ASSESSMENT OF STAND DENSITY AND GROWTH RATE OF ...

    African Journals Online (AJOL)

    ABIA

    Tectona grandis stands in the arboretum of the. Department of Forestry and Wildlife,. University of Uyo, have not been assessed for stand density and growth rates. Thus, there had been no data on the stand densities of these stands and the growth rates of the trees for rational decision making and sustainable management.

  3. Future directions in standing-wave photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Alexander X., E-mail: axgray@temple.edu

    2014-08-15

    Highlights: • Probing magnetic properties at the buried interface with SW-MCD. • Probing electronic structure at the buried interface with resonant SW-XPS and SW-HAXPES. • Probing momentum-resolved electronic structure at a buried interface with SWARPES. • Adding depth resolution to photoemission microscopy with standing-wave excitation. • Standing-wave localization, total reflection and waveguide effects. - Abstract: Over the past decade, standing-wave photoemission (SW-XPS) has evolved into a powerful and versatile non-destructive technique for probing element-specific electronic, magnetic, and structural properties of buried layers and interfaces with sub-nanometer depth resolution. In this article, I will discuss several promising future directions in this emergent field stemming from experimental and theoretical studies wherein SW-XPS is combined with other X-ray techniques, such as magnetic circular dichroism (MCD), hard X-ray photoemission spectroscopy (HAXPES), angle-resolved photoemission (ARPES), and photoemission microscopy (PEEM), adding extra dimensions to the measurement and thus widening the scope of scientific and technological questions accessible via the use of standing waves. I will further discuss examples of recently developed methods for X-ray standing-wave data analysis, which yield layer-resolved matrix-element-weighted densities of states at interfaces as well as Ångstrom-level changes in periodicity of synthetic superlattices. Finally, I will explore the possibility of localizing the standing waves near the surface and within a buried layer by the use of aperiodic superlattices, total reflection, and X-ray waveguide effects.

  4. Vine maple (Acer circinatum) clone growth and reproduction in managed and unmanaged coastal Oregon douglas-fir forests

    Science.gov (United States)

    O'Dea, Mary E.; Zasada, John C.; Tappeiner, John C.

    1995-01-01

    Vine maple (Acer circinatum Pursh.) clone development, expansion, and regeneration by seedling establishment were studied in 5-240 yr old managed and unmanaged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in coastal Oregon. Stem length, number of stems, and crown area were all significantly (P @10 m long and basal sprouts 1-2 m long; some stems had been pinned to the forest floor by fallen trees or branches and had layered. In stands >120 yr in age, clones were often quite complex, composed of several decumbent stems each of which connected the ramets of 1-10 new aerial stems. Vine maple clone expansion occurs by the layering of long aerial stems. Over 95% of the layered stems we observed had been pinned to the forest floor by fallen debris. Unsevered stems that we artificially pinned to the forest floor initiated roots within 1 yr. Thinning may favor clonal expansion because fallen slash from thinning often causes entire clones to layer, not just individual stems. Clonal vine maple seed production and seedling establishment occurred in all stages of stand development except dense, young stands following crown closure. There were more seedlings in thinned stands than in unthinned stands and in unburned clearcuts than in burned clearcuts.

  5. Sliding and Lower Limb Mechanics during Sit-Stand-Sit Transitions with a Standing Wheelchair

    Directory of Open Access Journals (Sweden)

    Yu-Sheng Yang

    2014-01-01

    Full Text Available Purpose. This study aimed to investigate the shear displacement between the body and backrest/seat, range of motion (ROM, and force acting on the lower limb joints during sit-stand-sit transitions by operating an electric-powered standing wheelchair. Methods and Materials. The amounts of sliding along the backrest and the seat plane, ROM of lower limb joints, and force acting on the knee/foot were measured in twenty-four people with paraplegia. Results. Without an antishear mechanism, the shear displacement was approximately 9 cm between the user’s body and the backrest/seat surfaces. During standing up, the user’s back slid down and the thigh was displaced rearward, but they moved in opposite directions when wheelchair sat back down. A minimum of 60 degrees of ROM at the hip and knee was needed during sit-stand-sit transitions. The maximal resultant forces acting on the knee restraints could reach 23.5% of body weight. Conclusion. Sliding between the body and backrest/seat occurred while transitioning from sitting to standing and vice versa. A certain amount of ROM at lower limb joints and force acting on the knee was necessitated during sit-stand-sit transitions. Careful consideration needs to be given to who the user of the electric powered standing wheelchair is.

  6. Learning to Stand: The Acceptability and Feasibility of Introducing Standing Desks into College Classrooms

    Directory of Open Access Journals (Sweden)

    Roberto M. Benzo

    2016-08-01

    Full Text Available Prolonged sedentary behavior is an independent risk factor for multiple negative health outcomes. Evidence supports introducing standing desks into K-12 classrooms and work settings to reduce sitting time, but no studies have been conducted in the college classroom environment. The present study explored the acceptability and feasibility of introducing standing desks in college classrooms. A total of 993 students and 149 instructors completed a single online needs assessment survey. This cross-sectional study was conducted during the fall semester of 2015 at a large Midwestern University. The large majority of students (95% reported they would prefer the option to stand in class. Most students (82.7% reported they currently sit during their entire class time. Most students (76.6% and instructors (86.6% reported being in favor of introducing standing desks into college classrooms. More than half of students and instructors predicted having access to standing desks in class would improve student’s “physical health”, “attention”, and “restlessness”. Collectively, these findings support the acceptability of introducing standing desks in college classrooms. Future research is needed to test the feasibility, cost-effectiveness and efficacy of introducing standing desks in college classrooms. Such studies would be useful for informing institutional policies regarding classroom designs.

  7. AA, wide quadrupole on measurement stand

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    Please look up 8101024 and 8103203 first. Wide quadrupole (QFW, QDW) with end-shims and shimming washers on the measurement stand. With the measurement coil one measured the harmonics of the magnetic field, determined the magnetic centre, and catalogued the effect of washer constellations.

  8. Large optics inspection, tilting, and washing stand

    Science.gov (United States)

    Ayers, Marion Jay [Brentwood, CA; Ayers, Shannon Lee [Brentwood, CA

    2010-08-24

    A large optics stand provides a risk free means of safely tilting large optics with ease and a method of safely tilting large optics with ease. The optics are supported in the horizontal position by pads. In the vertical plane the optics are supported by saddles that evenly distribute the optics weight over a large area.

  9. LITTERFALL AND NUTRIENT RETURNS IN ISOLATED STANDS ...

    African Journals Online (AJOL)

    Dr Osondu

    and branch morphology, leaf size and arrangement. The main objective of this study was to examine litter production and nutrient returns through litterfall by isolated stands of Terminalia catappa, and determine the contributions of nutrient elements to the rainforest soil by the isolated exotic, through a direct comparison with.

  10. A3 TEST STAND DEVELOPMENT AND CONSTRUCTION

    Science.gov (United States)

    2008-01-01

    THIS IMAGE DOCUMENTS THE DEVELOPMENT AND CONSTRUCTION OF THE A3 TEST STAND IN SUPPORT OF THE ARES/CLV UPPER STAGE ENGINE DEVELOPMENT AT STENNIS SPACE CENTER, MISSIPPI IN SUPPORT OF THE DEVELOPMENT OF THE CONSTELLATION/ARES PROJECT. THIS IMAGE IS EXTRACTED FROM A HIGH DEFINITION VIDEO FILE AND IS THE HIGHEST RESOLUTION AVAILABLE

  11. Large optics inspection, tilting, and washing stand

    Science.gov (United States)

    Ayers, Marion Jay; Ayers, Shannon Lee

    2012-10-09

    A large optics stand provides a risk free means of safely tilting large optics with ease and a method of safely tilting large optics with ease. The optics are supported in the horizontal position by pads. In the vertical plane the optics are supported by saddles that evenly distribute the optics weight over a large area.

  12. Direct sampling for stand density index

    Science.gov (United States)

    Mark J. Ducey; Harry T. Valentine

    2008-01-01

    A direct method of estimating stand density index in the field, without complex calculations, would be useful in a variety of silvicultural situations. We present just such a method. The approach uses an ordinary prism or other angle gauge, but it involves deliberately "pushing the point" or, in some cases, "pulling the point." This adjusts the...

  13. Sherry Red Owl, Stands at Dawn Woman

    Science.gov (United States)

    Crazy Bull, Cheryl

    2014-01-01

    This article introduces Sherry Red Owl, also known as "Stands at Dawn Woman," because she greets each day as a new opportunity and has spent her life working at new things. She worked at Sinte Gleska University (SGU) during its founding years, taught at an elementary school when few Native teachers were employed in the school systems,…

  14. Standing waves in fiber-optic interferometers

    NARCIS (Netherlands)

    De Haan, V.; Santbergen, R.; Tijssen, M.; Zeman, M.

    2011-01-01

    A study is presented giving the response of three types of fiber-optic interferometers by which a standing wave through an object is investigated. The three types are a Sagnac, Mach–Zehnder and Michelson–Morley interferometer. The response of the Mach–Zehnder interferometer is similar to the Sagnac

  15. Effects of Stand and Step Training with Epidural Stimulation on Motor Function for Standing in Chronic Complete Paraplegics.

    Science.gov (United States)

    Rejc, Enrico; Angeli, Claudia A; Bryant, Nicole; Harkema, Susan J

    2017-05-01

    Individuals affected by motor complete spinal cord injury are unable to stand, walk, or move their lower limbs voluntarily; this diagnosis normally implies severe limitations for functional recovery. We have recently shown that the appropriate selection of epidural stimulation parameters was critical to promoting full-body, weight-bearing standing with independent knee extension in four individuals with chronic clinically complete paralysis. In the current study, we examined the effects of stand training and subsequent step training with epidural stimulation on motor function for standing in the same four individuals. After stand training, the ability to stand improved to different extents in the four participants. Step training performed afterwards substantially impaired standing ability in three of the four individuals. Improved standing ability generally coincided with continuous electromyography (EMG) patterns with constant levels of ground reaction forces. Conversely, poorer standing ability was associated with more variable EMG patterns that alternated EMG bursts and longer periods of negligible activity in most of the muscles. Stand and step training also differentially affected the evoked potentials amplitude modulation induced by sitting-to-standing transition. Finally, stand and step training with epidural stimulation were not sufficient to improve motor function for standing without stimulation. These findings show that the spinal circuitry of motor complete paraplegics can generate motor patterns effective for standing in response to task-specific training with optimized stimulation parameters. Conversely, step training can lead to neural adaptations resulting in impaired motor function for standing.

  16. Douglas-fir displays a range of growth responses to ...

    Science.gov (United States)

    Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) growth in the Pacific Northwest is affected by climatic, edaphic factors and Swiss needle cast (SNC) disease. We examine Douglas-fir growth responses to temperature, dewpoint deficit (DPD), soil moisture, and SNC using time series intervention analysis of intra-annual tree-ring width data collected at nine forest stands in western Oregon, USA. The effects of temperature and SNC were similar in importance on tree growth at all sites. Previous-year DPD during the annual drought period was a key factor limiting growth regionally. Winter temperature was more important at high elevation cool sites, whereas summer temperature was more important at warm and dry sites. Growth rate increased with summer temperature to an optimum (Topt) then decreased at higher temperatures. At drier sites, temperature and water affected growth interactively such that Topt decreased with decreasing summer soil moisture. With climate change, growth rates increased at high elevation sites and declined at mid-elevation inland sites since ~1990. Growth response to climate is masked by SNC regionally. We conclude that as temperature rises and precipitation patterns shift towards wetter winters and drier summers, Douglas-fir will experience greater temperature and water stress and an increase in severity of SNC. By the end of the 21st century, climate models predict hotter, drier summers and warmer, wetter winters in the Pac

  17. Ammonium nitrate, urea, and biuret fertilizers increase volume growth of 57-year-old douglas-fir trees within a gradient of nitrogen deficiency. Forest Service research paper

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.E.; Reukema, D.L.; Hazard, J.W.

    1996-03-01

    In a nitrogen-deficient plantation in southwest Washington, the authors (1) compared effects of 224 kg N/ha as ammonium nitrate, urea, and biuret on volume growth of dominant and codominant Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco); (2) determined how 8-year response of these trees to fertilization was related to their distance from a strip of the plantation interplanted with nitrogen-fixing red alder (alnus rubra Bong.); and (3) observed effects of biuret on understory vegetation. On both sides of the strip centerline, the authors grouped subject trees into 30 plots of 4 trees each, based on slope position and distance from alder. The authors randomly assigned three fertilizers and a control within each plot. They analyzed separately data from east and west of the mixed stand certerline. Initial volume differed greatly among the 120 trees on each side, so they used covariance analysis to adjust observed treatment means. Adjusted mean volume growth was increased (p equal to or less than 0.10) by 22 to 28 percent on the east side and by 11 to 14 percent on the west side, with no significant difference in response to the three fertilizers.

  18. Kinetic asymmetry in transfemoral amputees while performing sit to stand and stand to sit movements.

    Science.gov (United States)

    Highsmith, M Jason; Kahle, Jason T; Carey, Stephanie L; Lura, Derek J; Dubey, Rajiv V; Csavina, Kristine R; Quillen, William S

    2011-05-01

    Transitional movements are a determinant of functional independence and have limited study in amputees. Microprocessor prosthetic knees' abilities to assist transfemoral amputees with sitting and standing have not been studied. Through cross-sectional study, 21 transfemoral amputees, divided into 3 groups of 7 by knee type (power knee, C-leg, Mauch SNS) and 7 non-amputee controls (n=28) performed sit to stand and stand to sit while kinematic and kinetic data were recorded. Transfemoral amputees can stand (1.6-2.0s) and sit (2.1-2.8s) at rates comparable to controls (1.6s). Controls' ground reaction force (GRF) and knee moment production was knee moments. For stand to sit, amputees' asymmetry for GRF ranged from 32 to 60% and 84 to 114% for knee moments. Hip moment asymmetry for sit to stand was less for control (21%) and power knee (34%) groups than that produced by the Mauch SNS (59%) group. For stand to sit, hip moment production for the Mauch SNS (47%) and C-leg groups (71%) were more asymmetric than controls (19%). In the majority of cases transfemoral amputees do not load their prosthesis extensively for standing up or sitting down. Therefore, this transitional movement is currently a one-legged task, which increases stress on the sound limb. Generally, the prosthetic knees studied did not produce a significant knee moment in either task. Although most differences between knee groups were not statistically significant, differences may be clinically meaningful on an individual basis. Published by Elsevier B.V.

  19. Aircraft Stand Allocation with Associated Resource Scheduling

    DEFF Research Database (Denmark)

    Justesen, Tor Fog; Larsen, Jesper; Lusby, Richard Martin

    An aircraft turn-round refers to the set of processes taking place from when an aircraft parks at its arrival stand until the time it departs from its departure stand. When handling a turn-round, the different processes involved (arrival, disembarkation of passengers, cleaning, etc.) require...... to handle a given set of aircraft turn-rounds. We develop a set packing-based model formulation of the problem which is both flexible in the sense that it can encapsulate any type of resource required during the handling of a turn-round and strong in the sense that conflicts that occur when two or more turn......-rounds simultaneously claim the same resource are handled implicitly. To solve the model, a heuristic based on linear programming is developed. The heuristic iteratively solves a relaxed, restricted version of the problem, adding extra variables at each iteration if needed. The additional variables are identified...

  20. Standing seats for high-capacity trains

    Directory of Open Access Journals (Sweden)

    Conor O’NEILL

    2014-10-01

    Full Text Available This paper details the design and potential implementation of standing seats in a commuter rail vehicle for the purposes of maximising capacity and revenue. The vehicle interior design is suited to the “Commuter Class” – a subset of travellers who travel primarily within the commuter belt and frequently utilise rail networks on a daily basis but require little additional space for luggage or peripherals. The concept delivers capacity increases in excess of 50% whilst still offering passengers a greater degree of personal space when compared with standing in aisles or gangways. The impact on vehicle stability and supporting intelligent systems are also discussed, delivering a unique design tailored specifically to meet the needs of the commuter class passenger.

  1. Residual liquefaction of seabed under standing waves

    DEFF Research Database (Denmark)

    Kirca, V.S. Ozgur; Sumer, B. Mutlu; Fredsøe, Jørgen

    2013-01-01

    This paper presents the results of an experimental study of the seabed liquefaction beneath standing waves. Silt (with d50 =0.070mm) was used in the experiments. Two kinds of measurements were carried out: pore water pressure measurements and water surface elevation measurements. These measurements...... were synchronized with video recording of the liquefaction process from the side. The ranges of the various quantities in the experiments were wave height H= 5.9-12.0 cm, wave period T= 1.09s, and water depth h=30 cm. The experiments show that the seabed liquefaction under standing waves, although...... qualitatively similar, show features different from that caused by progressive waves. The pore water pressure builds up (or accumulated) in the areas around the node and subsequently spreads out toward the antinodes. The experimental results imply that this transport is caused by a diffusion mechanism...

  2. Mixed stands in Nordic countries - a challenge for the future

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, T. [Swedish University of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Management and Products

    2003-05-01

    Mixed stands are the most frequent type of stand in Nordic countries. A mixture of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) is the most common stand type in the region. But for most foresters and persons familiar with forestry, a mixed stand implies a conifer species and at least one broad-leaved species. Management and silviculture of mixed stands of conifers and broad-leaves has increased rapidly during the last 15 years. Efficient management of mixed stands increases profits for the owner as well as wood quality in the stand. Practical examples of how to manage mixed stands of birch (Betula pendula Roth and Betula pubescens Ehrh.) and Norway spruce are now available. In Finland, Norway and Sweden this is a common alternative to management of pure stands of conifers. In Norway, as well as mixed stands of birch and spruce, there are examples of mixed stands of European aspen (Populus tremula L.) and Norway spruce. Existing yield information for mixed stands is based on studies of stands which were managed improperly prior to the start of the study. The yield for birch at 35 years of age was 1 00 m{sup 3} ha{sup -1}. The growth of Norway spruce was reduced by 10% compared with spruce growing in pure spruce stands. In a mixed stand of European aspen and Norway spruce growing on farm land, the 36-year-old aspen overstory produced 480 m{sup 3} ha{sup -1}. The spruce understory had a reduced yield compared with pure spruce stands. Depending on the biofuel price and the market for utilisation of biofuel the forest owner might use the broad-leaves as biofuel. Some studies indicate that the harvested biomass yield of birch in a mixed stand of birch and spruce could be 48 td.w.ha{sup -1}. (author)

  3. MICROSCALE METROLOGY USING STANDING WAVE PROBES

    Energy Technology Data Exchange (ETDEWEB)

    Bauza, M B; Woody, S C; Smith, S T; Seugling, R M; Darnell, I; Florando, J N

    2008-08-04

    Miniaturization has been one of the driving forces in the development of new technologies leading to new products in a variety of industries. As a result, the integration of components over several orders of magnitude on the length scale poses enormous challenges for quality assurance and control. Therefore, new solutions are necessary to meet the growing need for more challenging metrology tasks and metrology requirements in nano- and micro-technology. However, with miniaturization, new challenges arise such as the increased influence of adhesion, electrostatic, Van der Waals and meniscus forces that affect the measurement process. Technical solutions to overcome these micro- and nano-metrology challenges will include the need for traceability, new calibration procedures and calibration artifacts. Over the past decade many new metrology tools have been proposed, however; for contact based measurements, adhesion between the measurement probe and the specimen still proves to be one of the more difficult challenges to overcome. To address this issue, a new class of tactile sensing probe referred to as standing wave sensor has been developed and was previously presented. Previous work introduced the principle of operation of the standing wave senor. This work presents new measurements showing applications of the standing wave probe as the sensing element in a microscale high aspect ratio profiling system.

  4. Test Stand for Linear Induction Accelerator Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Ong, M; DeHope, B; Griffin, K; Goerz, D; Kihara, R; Vogtlin, G; Zentler, J M; Scarpetti, R

    2003-06-03

    Lawrence Livermore National Laboratory has designed and constructed a test stand to improve the voltage regulation in our Flash X-Ray (FXR) accelerator cell. The goal is to create a more mono-energetic electron beam that will create an x-ray source with a smaller spot size. Studying the interaction of the beam and pulse-power system with the accelerator cell will improve the design of high-current accelerators at Livermore and elsewhere. On the test stand, a standard FXR cell is driven by a flexible pulse-power system and the beam current is simulated with a switched center conductor. The test stand is fully instrumented with high-speed digitizers to document the effect of impedance mismatches when the cell is operated under various full-voltage conditions. A time-domain reflectometry technique was also developed to characterize the beam and cell interactions by measuring the impedance of the accelerator and pulse-power component. Computer models are being developed in parallel with the testing program to validate the measurements and evaluate different design changes. Both 3D transient electromagnetic and circuit models are being used.

  5. Tropical forest biomass estimation from truncated stand tables.

    Science.gov (United States)

    A. J. R. Gillespie; S. Brown; A. E. Lugo

    1992-01-01

    Total aboveground forest biomass may be estimated through a variety of techniques based on commercial inventory stand and stock tables. Stand and stock tables from tropical countries commonly omit trees bellow a certain commercial limit.

  6. Forest evaporation models: Relationships between stand growth and evaporation

    CSIR Research Space (South Africa)

    Le Maitre, David C

    1997-06-01

    Full Text Available The relationships between forest stand structure, growth and evaporation were analysed to determine whether forest evaporation can be estimated from stand growth data. This approach permits rapid assessment of the potential impacts of afforestation...

  7. Stand structure and regeneration of harvested Araucaria araucana ...

    African Journals Online (AJOL)

    Stand structure and regeneration of harvested Araucaria araucana–Nothofagus stands in central Chile. Rafael M Navarro-Cerrillo, Fernando Olave, Francisco Moreno, Sergio de Miguel, Margarita Clemente ...

  8. The zero inflation of standing dead tree carbon stocks

    Science.gov (United States)

    Christopher W. Woodall; David W. MacFarlane

    2012-01-01

    Given the importance of standing dead trees in numerous forest ecosystem attributes/processes such as carbon (C) stocks, the USDA Forest Service’s Forest Inventory and Analysis (FIA) program began consistent nationwide sampling of standing dead trees in 1999. Modeled estimates of standing dead tree C stocks are currently used as the official C stock estimates for the...

  9. Stocking equations for regeneration in mixed oak stands

    Science.gov (United States)

    Songlin Fei; Kim C. Steiner; James C. Finley

    2007-01-01

    Regeneration stocking equations for mixed-oak stands were developed based on data collected from nearly 14,000 plots in the central Appalachians. Maximum stand density was identified by plotting aggregate height against number of seedlings per plot, and was used as the reference level of the average maximum stand density (100 percent stocking or A-level stocking)....

  10. Standing Sound Waves in Air with DataStudio

    Science.gov (United States)

    Kraftmakher, Yaakov

    2010-01-01

    Two experiments related to standing sound waves in air are adapted for using the ScienceWorkshop data-acquisition system with the DataStudio software from PASCO scientific. First, the standing waves are created by reflection from a plane reflector. The distribution of the sound pressure along the standing wave is measured. Second, the resonance…

  11. 28 CFR 7.1 - Standing offer of reward.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Standing offer of reward. 7.1 Section 7.1 Judicial Administration DEPARTMENT OF JUSTICE REWARDS FOR CAPTURE OF ESCAPED FEDERAL PRISONERS § 7.1 Standing offer of reward. A standing offer of reward is made for the capture, or for assisting in, or...

  12. A Fresh Look at Longitudinal Standing Waves on a Spring

    Science.gov (United States)

    Rutherford, Casey

    2013-01-01

    Transverse standing waves produced on a string, as shown in Fig. 1, are a common demonstration of standing wave patterns that have nodes at both ends. Longitudinal standing waves can be produced on a helical spring that is mounted vertically and attached to a speaker, as shown in Fig. 2, and used to produce both node-node (NN) and node-antinode…

  13. Standing dead tree resources in forests of the United States

    Science.gov (United States)

    Christopher W. Woodall; Karen L. Waddell; Christopher M. Oswalt; James E. Smith

    2013-01-01

    Given the importance of standing dead trees to numerous forest ecosystem attributes/ processes such as fuel loadings and wildlife habitat, the Forest Inventory and Analysis (FIA) Program of the Forest Service, U.S. Department of Agriculture, initiated a consistent nationwide inventory of standing dead trees in 1999. As the first cycle of annual standing dead tree...

  14. A comparison of northern and southern table mountain pine stands

    Science.gov (United States)

    Patrick H. Brose; Thomas A. Waldrop; Helen H. Mohr

    2010-01-01

    Table Mountain pine (Pinus pungens) stands occur throughout the Appalachian Mountains, but ecological research has concentrated on the southern part of this region. In 2006, research was initiated in northern Table Mountain pine stands growing in PA to compare some basic attributes of those stands with previously described ones in TN. Overall, the...

  15. Production economics of harvesting young hardwood stands in central Appalachia

    Science.gov (United States)

    Yaoxiang Li; Jingxin Wang; Gary W. Miller; Joe McNeel

    2004-01-01

    Three harvesting systems of chainsaw/cable skidder, fell-buncher/grapple skidder, and harvester/forwarder were simulated in harvesting three hardwood stands of 30 to 50 years old in central Appalachia. Stands were generated by using a stand generator and harvesting prescriptions included clearcut, shelterwood cut, selective cut, diameter limit cut, and crop tree...

  16. A 3D stand generator for central Appalachian hardwood forests

    Science.gov (United States)

    Jingxin Wang; Yaoxiang Li; Gary W. Miller

    2002-01-01

    A 3-dimensional (3D) stand generator was developed for central Appalachian hardwood forests. It was designed for a harvesting simulator to examine the interactions of stand, harvest, and machine. The Component Object Model (COM) was used to design and implement the program. Input to the generator includes species composition, stand density, and spatial pattern. Output...

  17. Diameter Distributions in Natural Yellow-Poplar Stands

    Science.gov (United States)

    Charles E. McGee; Lino Della-Bianca

    1967-01-01

    Diameter distributions obtained from 141 pure, natural unthinned yellow-poplar stands in the Appalachian Mountains of Virginia, North Carolina, and Georgia are presented in tables. The distributions are described in relation to stand age, site index, and total number of trees per acre, and are useful for stand management planning.

  18. Effect of tree-growth rate on papermaking fibre properties

    Science.gov (United States)

    J. Y. Zhu; D. W. Vahey; C. T. Scott; G. C. Myers

    2008-01-01

    Measurements of wood density and anatomical properties of wood disks were conducted by SilviScan (CSIRO Australia) and a new imaging technique. The disks included red pine (Pinus resinosa Ait.) obtained from a never-thinned experimental forest with five different plantation densities and Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and lodgepole...

  19. The wind stability of different silvicultural systems for Douglas-fir in The Netherlands: a model-based approach

    NARCIS (Netherlands)

    Schelhaas, M.J.

    2008-01-01

    The aim of this study was to evaluate different silvicultural systems for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Netherlands in terms of timber production and wind stability over a full rotation. This was done using the forest genetics, ecology, management and wind model

  20. Species-specific partitioning of soil water resources in an old-growth Douglas-fir/western hemlock forest.

    Science.gov (United States)

    F.C. Meinzer; J.M. Warren; J.R. Brooks

    2007-01-01

    We studied seasonal courses of soil water utilization in a 450-year-old Pseudotsuga menziesii/Tsuga heterophylla forest. Mean root area in the upper 60 cm of soil was significantly greater in the vicinity of T. heterophylla trees. However, seasonal water extraction on a root area basis was significantly...

  1. Wildlife and invertebrate response to fuel reduction treatments in dry coniferous forests of the Western United States: a synthesis

    Science.gov (United States)

    David S. Pilliod; Evelyn L. Bull; Jane L. Hayes; Barbara C. Wales

    2006-01-01

    This paper synthesizes available information on the effects of hazardous fuel reduction treatments on terrestrial wildlife and invertebrates in dry coniferous forest types in the West. We focused on thinning and/or prescribed fire studies in ponderosa pine (Pinus ponderosa) and dry-type Douglas-fir (Pseudotsuga menziesii),...

  2. Surface fire effects on conifer and hardwood crowns--applications of an integral plume model

    Science.gov (United States)

    Matthew Dickinson; Anthony Bova; Kathleen Kavanagh; Antoine Randolph; Lawrence Band

    2009-01-01

    An integral plume model was applied to the problems of tree death from canopy injury in dormant-season hardwoods and branch embolism in Douglas fir (Pseudotsuga menziesii) crowns. Our purpose was to generate testable hypotheses. We used the integral plume models to relate crown injury to bole injury and to explore the effects of variation in fire...

  3. Modeling regional and climatic variation of wood density and ring width in intensively managed Douglas-fir

    Science.gov (United States)

    Cosmin N. Filipescue; Eini C. Lowell; Ross Koppenaal; Al K. Mitchell

    2014-01-01

    Characteristics of annual rings are reliable indicators of growth and wood quality in trees. The main objective of our study was to model the variation in annual ring attributes due to intensive silviculture and inherent regional differences in climate and site across a wide geographic range of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)....

  4. Vegetation control effects on untreated wood, crude cellulose and holocellulose 𗉝C of early and latewood in 3- to 5-year-old rings of Douglas-fir

    Science.gov (United States)

    Adrian Ares; Constance A Harrington; Thomas A. Terry; Joseph M. Kraft

    2009-01-01

    The stable carbon (C) composition of tree rings expressed as 13C, is a measure of intrinsic water-use efficiency and can indicate the occurrence of past water shortages for tree growth. We examined 13C in 3- to 5-year-old rings of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees...

  5. Interim definitions for old growth Douglas-fir and mixed-conifer forests in the Pacific Northwest and California.

    Science.gov (United States)

    J.F. Franklin; F. Hall; W. Laudenslayer; C. Maser; J. Nunan; J. Poppino; C.J. Ralph; T. Spies

    1986-01-01

    Interim definitions of old-growth forests are provided to guide efforts in land-management planning until comprehensive definitions based on research that is currently underway can be formulated. The basic criteria for identifying old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and mixed-conifer forests in western Washington and...

  6. Pityophthorus orarius Bright (Coleoptera: Scolytidae) in a northern California Douglas-fir seed orchard: effect of clone, tree vigor, and cone crop on rate of attack

    Science.gov (United States)

    Nancy G. Rappaport; David L. Wood

    1994-01-01

    The geographic range of the Douglas-fir twig beetle, Pityophthorus orarius Bright, was extended beyond the original provenance of southern British Columbia to northern California. A survey of 457 Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] trees in 1985 revealed that those with heavy cone crops were more likely to be...

  7. Resource use and clonal differences in attack rate by the Douglas-fir seed chalcid, Megastigmus spermotrophus Wachtl (Hymenoptera: Torymidae), in France

    Science.gov (United States)

    Nancy Rappaport; Alain Roques

    1991-01-01

    The within-cone distribution of Megastigmus spermotrophus Wachtl (Hymenoptera: Torymidae), the Douglas-fir seed chalcid, infesting Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] cones from north-central France was compared with that in samples from California. Results indicate that the mid-region of cones was more intensively...

  8. Bedrock type significantly affects individual tree mortality for various conifers in the inland Northwest, U.S.A

    Science.gov (United States)

    James A. Moore; David A Hamilton; Yu Xiao; John Byrne

    2004-01-01

    Individual tree mortality models for western white pine (Pinus monticola Dougl. ex D. Don), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex. D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western larch (Larix occidentalis Nutt.) were developed using data...

  9. Spatial and population characteristics of dwarf mistletoe infected trees in an old-growth Douglas-fir - western hemlock forest.

    Science.gov (United States)

    David C. Shaw; Jiquan Chen; Elizabeth A. Freeman; David M. Braun

    2005-01-01

    We investigated the distribution and severity of trees infected with western hemlock dwarf mistletoe (Arceuthobium tsugense (Rosendahl) G.N. Jones subsp. tsugense) in an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) - western hemlock (Tsuga heterophylla (Raf.) Sarg.)...

  10. Assessing the specific energy consumption and physical properties of comminuted Douglas-fir chips for bioconversion

    Science.gov (United States)

    Yalan Liu; Jinwu Wang; Michael P. Wolcott

    2016-01-01

    Size reduction homogenizes the bulk biomass and facilitates downstream feedstock handling, transportation, and storage. Effects of feeding rate, mill-type (hammer and knife mill), screen size, and moisture content on comminution energy consumption of commercial Douglas-fir (Pseudotsuga menziesii) pulp chips were quantified. The resulting particles...

  11. Examining soil parent material influence over Douglas-fir stem growth response to fertilization: Taking advantage of information from spatiotemporally distributed experiments

    Science.gov (United States)

    Kevin P. White; Mark Coleman; Deborah S. Page-Dumroese; Paul E. Gessler; Mark Kimsey; Terry Shaw

    2012-01-01

    Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in the Inland Northwest region of the USA are nitrogen (N) deficient; however stem growth responses to N fertilizers are unpredictable, which may be due to poor accounting of other limiting nutrients. Screening trial experiments, including potassium (K), sulfur (S), and boron (B) multiple nutrient treatments, have been...

  12. Occurrence of shrubs and herbaceous vegetation after clear cutting old-growth Douglas-fir in the Oregon Cascades.

    Science.gov (United States)

    Vern P. Yerkes

    1960-01-01

    Land managers often express a need for more complete information about the vegetative cover that develops on cutover areas between harvest of old-growth Douglas-fir (Pseudotsuga menziesii) and establishment of a young-growth forest. The composition and density of this cover frequently determines the management techniques that must be used to...

  13. Current seed orchard techniques and innovations

    Science.gov (United States)

    Lawrence K. Miller; Jeffrey DeBell

    2013-01-01

    As applied forest tree improvement programs in the US Northwest move forward into the third cycle, seed orchards remain as the primary source of genetically improved forest tree seed used for reforestation. The vast majority of seed orchards in this region are coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), consistent with the high economic importance of...

  14. Developmental decline in height growth in Douglas-fir.

    Science.gov (United States)

    Barbara J. Bond; Nicole M. Czarnomski; Clifton Cooper; Michael E. Day; Michael S. Greenwood

    2007-01-01

    The characteristic decline in height growth that occurs over a tree's lifespan is often called "age-related decline." But is the reduction in height growth in aging trees a function of age or of size? We grafted shoot tips across different ages and sizes of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees to determine whether...

  15. The New Zealand douglas-fir breeding program: proposed adjustments for a changing climate

    Science.gov (United States)

    Heidi Dungey; Charlie Low; Mark Miller; Kane Fleet; Alvin D. Yanchuk

    2012-01-01

    Genetic improvement of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in New Zealand was initiated in 1955 with large provenance trials established in the late 1950s. These trials showed that material of Oregon and Californian origin was growing faster than other provenances. Additional collections were made to further evaluate provenance...

  16. Modeling effects of overstory density and competing vegetation on tree height growth

    Science.gov (United States)

    Christian Salas; Albert R. Stage; Andrew P. Robinson

    2007-01-01

    We developed and evaluated an individual-tree height growth model for Douglas-fir [Pseudotsuga menziesii (Mirbel) Franco] in the Inland Northwest United States. The model predicts growth for all tree sizes continuously, rather than requiring a transition between independent models for juvenile and mature growth phases. The model predicts the effects...

  17. MORPHOGENESIS OF DOUGLAS-FIR BUDS IN ALTERED AT ELEVATED TEMPERATURE BUT NOT AT ELEVATED CO21

    Science.gov (United States)

    Global climatic change as expressed by increased CO2 and temperature has the potential for dramatic effects on trees. To determine what its effects may be on Pacific Northwest forests, Douglas-fir (Pseudotsuga menziesii) seedlings were grown in sun-lit controlled environment cham...

  18. Tall oil precursors of Douglas fir

    Science.gov (United States)

    Daniel O. Foster; Duane F. Zinkel; Anthony H. Conner

    1980-01-01

    The sapwood and heartwood extractives of Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] and the tall oil in the kraft black liquor were characterized. On pulping, isomerization and conversion of conjugated resin acids to dehydroabietic acid was observed. Recovery of both fatty and resin acids from pulping was lower than predicted from the extractive composition....

  19. Effects of leader topping and branch pruning on efficiency of Douglas-fir cone harvesting with a tree shaker.

    Science.gov (United States)

    D.L. Copes

    1985-01-01

    In 1983, a study was conducted to evaluate the effects of leader topping and branch pruning on the efficiency to tree shaking to remove Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) cones. Removal efficiency for three topping and pruning treatments averaged 69 percent, whereas for the uncut control treatment it was 62 percent. The treatment...

  20. Effect of natural inbreeding on variance structure in tests of wind pollination Douglas-fir progenies.

    Science.gov (United States)

    Frank C. Sorensen; T.L. White

    1988-01-01

    Studies of the mating habits of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) have shown that wind-pollination families contain a small proportion of very slow-growing natural inbreds.The effect of these very small trees on means, variances, and variance ratios was evaluated for height and diameter in a 16-year-old plantation by...

  1. Growing reforestation conifer stock: Utilizing peat/sawdust medium

    Science.gov (United States)

    Janice K. Schaefer

    2009-01-01

    Western Forest Systems, Incorporated (WFS) (Lewiston, ID) has been utilizing a peat/sawdust blended mix as our growing medium for the past 10 years. Our decision to change from a peat/vermiculite blend to a peat/Douglas-fir (Pseudotsuga menziesii) sawdust blend involved worker health and safety issues, seedling culture, seedling production, and...

  2. Does habitat matter in an urbanized landscape? The birds of the Garry oak (Quercus garryana) ecosystem of southeastern Vancouver Island

    Science.gov (United States)

    Richard E. Feldman; Pamela G. Krannitz

    2002-01-01

    Garry oak (Quercus garryana) was once a dominant habitat type on southeastern Vancouver Island, British Columbia but urbanization has severely fragmented and reduced its occurrence. This study tests whether bird abundance in remnant patches of Garry oak and adjacent Douglas-fir (Pseudotsuga menziesii) is related to Garry oak volume...

  3. Estimating effect of Megastigmus spermotrophus (Hymenoptera: Torymidae) on Douglas-fir seed production: the new paradigm

    Science.gov (United States)

    Nancy Rappaport; Alain Roques; Sylvia Mori

    1993-01-01

    In a pollen exclusion experiment performed on the cones of five Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco) trees, the number of seeds infested by a seed chalcid, Megastigmus spermotrophus Wachtl, did not differ significantly between pollinated and unpollinated cones from the same tree. This finding led to a revision of the...

  4. Height-growth response to climatic changes differs among populations of Douglas-fir: A novel analysis of historic data

    Science.gov (United States)

    Laura P. Leites; Andrew P. Robinson; Gerald E. Rehfeldt; John D. Marshall; Nicholas L. Crookston

    2012-01-01

    Projected climate change will affect existing forests, as substantial changes are predicted to occur during their life spans. Species that have ample intraspecific genetic differentiation, such as Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), are expected to display population-specific growth responses to climate change. Using a mixed-effects modeling approach,...

  5. A spatial model for predicting effects of climate change on swiss needle cast disease severity in Pacific Northwest forests

    Science.gov (United States)

    Jeffrey K. Stone; Leonard B. Coop; Daniel K. Manter

    2010-01-01

    Swiss needle cast disease of Douglas-fir (Pseudotsuga menziesii) is caused by the ascomycete fungus Phaeocryptopus gaeumannii. Symptoms of the disease are foliage chlorosis and premature needle abscission due to occlusion of stomata by the ascocarps of the pathogen, resulting in impaired needle gas exchange. Severe defoliation...

  6. Cleaning to favor western white pine - its effects upon composition, growth, and potential values

    Science.gov (United States)

    Raymond J. Boyd

    1959-01-01

    The management of western white pine (Pinus monticola) requires the production of a high proportion of valuable white pine crop trees in order to defray the costs of protection from blister rust. Current average selling prices of lumber give white pine about $50 per m.b.f. advantage over western larch (Larix occidentalis) and Douglas-fir (Pseudotsuga menziesii), the...

  7. The 2002 Hayman Fire - ecological benefit or catastrophe? An understory plant community perspective

    Science.gov (United States)

    Paula Fornwalt

    2013-01-01

    Fire has long been a keystone ecological process in Western forests. In ponderosa pine (Pinus ponderosa)/Douglas-fir (Pseudotsuga menziesii) forests of the Colorado Front Range, historical fires are believed to have been "mixed severity" in nature. That means that these fires are believed to have typically burned within a range of severities from low severity...

  8. Postplanting sprays of dalapon and atrazine to aid conifer establishment.

    Science.gov (United States)

    Edward J. Dimock; Ernest B. Collard

    1981-01-01

    A mixture of dalapon and atrazine consistently controlled grasses of forbs better than either herbicide used alone. Sprayed over and around newly planted ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), the mixture doubled tree survival...

  9. First report of Fusarium proliferatum causing Fusarium root disease on sugar pine (Pinus lambertiana) in a forest container nursery in California

    Science.gov (United States)

    J. E. Stewart; K. Otto; G. A. Cline; Kas Dumroese; Ned Klopfenstein; M. -S. Kim

    2016-01-01

    Fusarium species, specifically F. commune, F. proliferatum, and F. solani, can cause severe damping-off and root disease in container and bareroot forest nurseries throughout North America. Many conifer and hardwood species can be affected, but Douglas-fir (Pseudotsuga menziesii), western white pine (Pinus monticola), and ponderosa pine (P. ponderosa) are known to be...

  10. Stress Wave E-Rating of Structural Timber—Size and Moisture Content Effects

    Science.gov (United States)

    Xiping Wang

    2013-01-01

    The objectives of this study were to investigate the influence of cross sectional size and moisture content on stress wave properties of structural timber in various sizes and evaluate the feasibility of using stress wave method to E-rate timber in green conditions. Four different sizes of Douglas-fir (Pseudotsuga menziesii) square timbers were...

  11. Sugar pine seed harvest by Clark's nutcracker: Annual use of a transient resource in Crater Lake National Park, Oregon

    Science.gov (United States)

    Taylor J. Turner; Diana F. Tomback; Bradley Van Anderson; Michael Murray

    2011-01-01

    Clark's nutcrackers (Nucifraga columbiana) are well known for using conifer seeds as their principal nutriment source. Seeds are primarily harvested from whitebark (Pinus albicaulis), piñon (P. edulis), limber (P. flexilis), southwestern white (P. strobiformis), Jeffrey (P. jeffreyi), and ponderosa (P. ponderosa) pine as well as Douglas-fir (Pseudotsuga menziesii...

  12. Rehabilitation of monotonous exotic coniferous plantations: A case study of spontaneous establishment of different tree species

    NARCIS (Netherlands)

    Jonásová, M.; Hees, van A.F.M.; Prach, K.

    2006-01-01

    Conversion of plantations of exotic coniferous species, such as Norway spruce (Picea abies), Douglas fir (Pseudotsuga menziesii) and Sitka spruce (Picea sitchensis), into more natural woodland is intended in two national parks in the province of Drenthe, The Netherlands. For that purpose, artificial

  13. Mixed-severity fire regimes in dry forests of southern interior British Columbia, Canada

    Science.gov (United States)

    Emily K. Heyerdahl; Ken Lertzman; Carmen M. Wong

    2012-01-01

    Historical fire severity is poorly characterized for dry forests in the interior west of North America. We inferred a multicentury history of fire severity from tree rings in Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) - ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) forests in the southern interior of British Columbia,...

  14. Disturbance impacts on understory plant communities of the Colorado Front Range

    Science.gov (United States)

    Paula J. Fornwalt

    2009-01-01

    Pinus ponderosa - Pseudotsuga menziesii (ponderosa pine - Douglas-fir) forests of the Colorado Front Range have experienced a range of disturbances since they were settled by European-Americans approximately 150 years ago, including settlement-era logging and domestic grazing, and more recently, wildfire. In this dissertation, I...

  15. Partial DNA sequencing of Douglas-fir cDNAs used in RFLP mapping

    Science.gov (United States)

    K.D. Jermstad; D.L. Bassoni; C.S. Kinlaw; D.B. Neale

    1998-01-01

    DNA sequences from 87 Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) cDNA RFLP probes were determined. Sequences were submitted to the GenBank dbEST database and searched for similarity against nucleotide and protein databases using the BLASTn and BLASTx programs. Twenty-one sequences (24%) were assigned putative functions; 18 of which...

  16. An examination of the genetic control of Douglas-fir vascular tissue phytochemicals: implications for black bear foraging.

    Science.gov (United States)

    Bruce A. Kimball; G.R. Johnson; Dale L. Nolte; Doreen L. Griffin

    1999-01-01

    Silvicultural practices can influence black bear (Ursus americanus) foraging preferences for Douglas-fir (Pseudotsuga menziesii) cambial-zone vascular tissues, but little is known about the role of genetics. To study the impact of genetic selection, vascular tissue samples were collected from Douglas-fir trees in six half-sib families from five...

  17. Acoustic sorting models for improved log segregation

    Science.gov (United States)

    Xiping Wang; Steve Verrill; Eini Lowell; Robert J. Ross; Vicki L. Herian

    2013-01-01

    In this study, we examined three individual log measures (acoustic velocity, log diameter, and log vertical position in a tree) for their ability to predict average modulus of elasticity (MOE) and grade yield of structural lumber obtained from Douglas-fir (Pseudotsuga menziesii [Mirb. Franco]) logs. We found that log acoustic velocity only had a...

  18. Effects of bear damage on Douglas-fir lumber recovery

    Science.gov (United States)

    Eini C. Lowell; Dennis Dykstra; George McFadden

    2009-01-01

    Bear activily resulting in injury to Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees has been documented as early as the mid-1850s in the Pacific Northwest. The study reported in this article was designed to help managers decide whether the common practice of removing the damaged but potentially valuable butt section of the bottom log and...

  19. Tree species is the major factor explaining C:N ratios in European forest soils

    DEFF Research Database (Denmark)

    Cools, Nathalie; Vesterdal, Lars; De Vos, Bruno

    2014-01-01

    .) and eucalyptus, the pine species and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) showed the highest C:N ratios in the mineral soil. The second most important explanatory variable in the forest floor and mineral topsoil was the biogeographical zoning (ecoregion). In the peat topsoil and in the deeper...

  20. Large wood recruitment and redistribution in headwater streams in the southern Oregon Coast Range, U.S.A.

    Science.gov (United States)

    C. L. May; R. E. Gresswell

    2003-01-01

    Abstract - Large wood recruitment and redistribution mechanisms were investigated in a 3.9 km 2 basin with an old-growth Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg. Forest, located in the southern Coast Range of Oregon. Stream size and topographic setting strongly influenced processes that delivered wood to the channel network. In small...

  1. Fire and mice: Seed predation moderates fire's influence on conifer recruitment

    Science.gov (United States)

    Rafal Zwolak; Dean E. Pearson; Yvette K. Ortega; Elizabeth E. Crone

    2010-01-01

    In fire-adapted ecosystems, fire is presumed to be the dominant ecological force, and little is known about how consumer interactions influence forest regeneration. Here, we investigated seed predation by deer mice (Peromyscus maniculatus) and its effects on recruitment of ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) seedlings in unburned...

  2. Using tree recruitment patterns and fire history to guide restoration of an unlogged ponderosa pine/Douglas-fir landscape in the southern Rocky Mountains after a century of fire suppression

    Science.gov (United States)

    Merrill R. Kaufmann; Laurie S. Huckaby; Paula J. Fornwalt; Jason M. Stoker; William H. Romme

    2003-01-01

    Tree age and fire history were studied in an unlogged ponderosa pine/Douglas-fir (Pinus ponderosa/Pseudotsuga menziesii) landscape in the Colorado Front Range mountains. These data were analysed to understand tree survival during fire and post-fire recruitment patterns after fire, as a basis for understanding the characteristics of, and restoration needs for, an...

  3. Dynamics of water transport and storage in conifers studied with deuterium and heat tracing techniques.

    Science.gov (United States)

    F.C. Meinzer; J.R. Brooks; J.-C. Domec; B.L. Gartner; J.M. Warren; D.R. Woodruff; K. Bible; D.C. Shaw

    2006-01-01

    The volume and complexity of their vascular systems make the dynamics of tong-distance water transport in large trees difficult to study. We used heat and deuterated water (D20) as tracers to characterize whole-tree water transport and storage properties in individual trees belonging to the coniferous species Pseudotsuga menziesii...

  4. Projected future suitable habitat and productivity of Douglas-fir in western North America

    Science.gov (United States)

    Aaron R. Weiskittel; Nicholas L. Crookston; Gerald E. Rehfeldt

    2012-01-01

    Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) is one of the most common and commercially important species in western North America. The species can occupy a range of habitats, is long-lived (up to 500 years), and highly productive. However, the future of Douglas-fir in western North America is highly uncertain due to the expected changes in climate conditions....

  5. Temporal and spatial changes in soil carbon and nitrogen after clearcutting and burning of an old-growth Douglas-fir forest.

    Science.gov (United States)

    Joseph A. Antos; Charles B. Halpern; Richard E. Miller; Kermit Cromack; Melora G. Halaj

    2003-01-01

    We used 135 permanent plots (4 m2) nested within 15 blocks (121 m2) to quantify changes in concentration and spatial variation of carbon (C) and nitrogen (N) in the mineral soil (0- to 10-cm depth) after logging and broadcast burning of an old-growth, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)...

  6. Soil disturbance and 10-year growth response of coast Douglas-fir on nontilled and tilled skid trails in the Oregon Cascades.

    Science.gov (United States)

    Ronald Heninger; William Scott; Alex Dobkowski; Richard Miller; Harry Anderson; Steve. Duke

    2002-01-01

    We (i) quantified effects of skidder yarding on soil properties and seedling growth in a portion of western Oregon, (ii) determined if tilling skid trails improved tree growth, and (iii) compared results with those from an earlier investigation in coastal Washington. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were hand planted at...

  7. Ground-based forest harvesting effects on soil physical properties and Douglas-fir growth.

    Science.gov (United States)

    Adrian Ares; Thomas A. Terry; Richard E. Miller; Harry W. Anderson; Barry L. Flaming

    2005-01-01

    Soil properties and forest productivity can be affected by heavy equipment used for harvest and site preparation but these impacts vary greatly with site conditions and operational practices. We assessed the effects of ground-based logging on soil physical properties and subsequent Douglas-fir [Pseudotsuga menziesii (Mirb) Franco] growth on a highly...

  8. Symptoms associated with inoculation of stems on living Douglas-fir and Grand Fir Trees with Phytophthora ramorum

    Science.gov (United States)

    Gary Chastagner; Kathy Riley; Katie Coats; Marianne Elliott; Annie DeBauw; Norm Dart

    2010-01-01

    To obtain a better understanding of the potential risk of infection and colonization of living Douglas-fir (Pseudotsuga menziesii) and grand fir (Abies grandis) stems, the stems on over 150 trees of each species were inoculated at a Christmas tree farm near Los Gatos, California. This study had the following objectives: 1)...

  9. Soil compaction and organic matter affect conifer seedling nonmycorrhizal and ectomycorrhizal root tip abundance and diversity.

    Science.gov (United States)

    Michael P. Amaranthus; Debbie Page-Dumroese; Al Harvey; Efren Cazares; Larry F. Bednar

    1996-01-01

    Three levels of organic matter removal (bole only; bole and crowns; and bole, crowns, and forest floor) and three levels of mechanical soil compaction (no compaction, moderate compaction, and severe soil compaction) were studied as they influence Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and western white...

  10. Hormonal control of second flushing in Douglas-fir shoots.

    Science.gov (United States)

    Morris Cline; Mark Yoders; Dipti Desai; Constance Harrington; William. Carlson

    2006-01-01

    Spring-flushing, over-wintered buds of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) produce new buds that may follow various developmental pathways. These include second flushing in early summer or dormancy before flushing during the following spring. Second flushing usually entails an initial release of apical dominance as some of the...

  11. Discerning responses of down wood and understory vegetation abundance to riparian buffer width and thinning treatments: an equivalence-inequivalence approach

    Science.gov (United States)

    Paul D. Anderson; Mark A. Meleason

    2009-01-01

    We investigated buffer width and thinning effects on the abundance of down wood and understory vegetation in headwater stream catchments of 40- to 65-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests in western Oregon, USA. Small-wood cover became more homogeneous among stream reaches within 5 years following thinning, primarily...

  12. Physiological responses of planting frozen and thawed Douglas-fir seedlings

    Science.gov (United States)

    M. Anisul Islam; Kent G. Apostol; Douglass F. Jacobs; R. Kasten Dumroese

    2008-01-01

    We studied the short-term (7-day) physiological responses of planting thawed and frozen root plugs of Douglas-fir (Pseudotsuga menziesii) seedlings in 2 separate experiments under cool-moist and warm-dry growing conditions, respectively. Our results showed that shoot water potential, root hydraulic conductance, net photosynthesis (A), and...

  13. Cherry Creek Research Natural Area: guidebook supplement 41

    Science.gov (United States)

    Reid Schuller; Jennie Sperling; Tim. Rodenkirk

    2011-01-01

    This guidebook describes Cherry Creek Research Natural Area, a 239-ha (590-ac) area that supports old-growth Douglas-fir-western hemlock (Pseudotsuga menziesii- Tsuga heterophylla) forest occurring on sedimentary materials in the southern Oregon Coast Range. Major plant associations present within the area include the western hemlock/Oregon oxalis...

  14. Changes in wood product proportions in the Douglas-fir region with respect to size, age, and time.

    Science.gov (United States)

    R.A. Monserud; X. Zhou

    2007-01-01

    We examine both the variation and the changing proportions of different wood products obtained from trees and logs in the Douglas-fir region of the Northwestern United States. Analyses are based on a large product recovery database covering over 40 years of recovery studies; 13 studies are available for Douglas-fir (Pseudotsuga menziesii (Mirb.)...

  15. Early genetic evaluation of open-pollinated Douglas-fir families

    Science.gov (United States)

    Kurt H. Riitters; David A. Perry

    1987-01-01

    In a test of early genetic evaluation of the growth potential of 14 families of open-pollinated Douglas-fir (Pseudotsuga menziesii) [Mirb.] Franco), measures of growth and phenology of seedligns grown in a coldframe were correlated with height of saplings in evaluation plantations at 9, 12, and 15 years. fifteen-year height was most strongly...

  16. Effects of Pinus flexilis on the dynamics and structure of plant communities on the northern Rocky Mountain front, and, Training biologists for emerging niches in non-traditional jobs

    Science.gov (United States)

    Baumeister, Dayna Marie

    My research examines the relative importance of interacting mechanisms (amelioration of wind, provision of shade, accumulation of snow pack, and alteration of soil characteristics) governing facilitation between Pinus flexilis and two understory species, Pseudotsuga menziesii and Ribes cereum in Montana. Survival of understory species was greatest beneath P. flexilis at a leeward site (Pseudotsuga, 38% and Ribes, 63%), and lowest in the open at a windward site (2% and 6%, respectively). The effects of wind amelioration, shade provision, and snowdrift accumulation were separated experimentally and after two years, shade was of overwhelming importance for the survival of both species. Once shade was provided, effects of wind amelioration and increased snow pack increased survival, suggesting a hierarchical functioning of mechanisms. High winter mortality of Pseudotsuga suggests P. flexilis canopies may prevent photoinhibition and winter desiccation through reduction of light and insulation from variable temperatures. High summer mortality of Ribes suggests P. flexilis canopies may reduce transpiration through lowering leaf temperatures, thereby decreasing vapor pressure deficits. In this system, several mechanisms governing facilitation operated simultaneously, but in a hierarchical manner of relative importance thereby determining the overall effect of P. flexilis on understory plants. I also studied facilitation and secondary succession by examining understory species composition beneath individual P. flexilis and in P. flexilis stands. As P. flexilis trees and stands aged, understory species richness increased, as did cover of forbs and shrubs, but cover of grasses decreased. Stands currently dominated by P. flexilis are shifting towards dominance by Pseudotsuga primarily in mesic sites, with corresponding increases in litter and shrub cover and decreases in grasses and P. flexilis recruitment. Since the 1860's succession from grasslands to forest on the Front has

  17. Stand development and yields of Appalachian hardwood stands managed with single-tree selection for at least 30 years

    Science.gov (United States)

    Neil I Lamson; H. Clay Smith; H. Clay Smith

    1991-01-01

    Appalachian hardwood stands in West Virginia were managed for 30 or more years using single-tree selection regeneration practices. Stand yield data suggest that current stand growth will provide economical harvest cuts for several future cutting cycles. This case study indicates that the single-tree selection practice has potential for landowners who want to maintain...

  18. Stand quality management in a late-rotation, red oak-sweetgum stand in east Mississippi: preliminary results following thinning

    Science.gov (United States)

    James S. Meadows; Daniel A. Skojac

    2012-01-01

    Stand quality management is a new management strategy in which thinning prescriptions are based solely on tree quality rather than a quantitative level of residual stand density. As long as residual density falls within fairly broad limits, prescriptions are based on tree quality alone. We applied four thinning prescriptions based on stand quality management, along...

  19. Coxofemoral joint radiography in standing cattle.

    Science.gov (United States)

    Wenzinger, Beatrice; Hagen, Regine; Schmid, Tanja; Nuss, Karl

    2012-01-01

    The objective of this study was to establish a technique for radiographic examination of the coxofemoral joint and adjacent bony structures in standing cattle. Left (or right) 30° dorsal-right (or left) ventral radiographic views of the coxofemoral joint region of standing cattle (n = 10) with hind limb lameness were evaluated retrospectively. In addition, an experimental study of oblique laterolateral views of the coxofemoral joint region of a bovine skeleton at angles of 15-45° was carried out to determine the optimal position for visualization of the hip region. In the 10 clinical patients, the bodies of the ilium and ischium, the acetabulum and proximal third of the femur could be assessed. Six of these cattle had fractures of the body of the ilium and body of the ischium, five with and one without involvement of the acetabulum, two had craniodorsal and one caudoventral luxation of the femur and one had a femoral neck fracture. The described laterodorsal-lateroventral radiographs of the hip region in standing cattle were suitable for assessing the coxofemoral joint, the proximal aspect of the femur and parts of the ischium, ilium and pubis. After testing the optimal angle on the skeleton, it was seen that distortion and superimposition were minimized by positioning the X-ray beam at an angle of 25° to the horizontal plane. It can be concluded that the described technique improves the evaluation of injuries of the coxofemoral region in cattle. With the appropriate angle, the technique can also be applied in recumbent cattle. © 2012 Veterinary Radiology & Ultrasound.

  20. Stand for testing sections of mechanized timbering

    Energy Technology Data Exchange (ETDEWEB)

    Grebennikov, Yu.N.; Aksenov, Yu.G.; Khazanov, Kh.I.; Khazin, V.A.; Radulov, V.Ye.; Vavilov, V.V.

    1982-01-01

    The purpose of the invention is to bring the testing conditions closer to the operating with multiple loading. This goal is achieved because in the stand for testing sections of mechanized timbering which includes a power frame, loading device with support and hydraulic equipment, the loading device is made in the form of enclosure sprockets and infinite mobile gears surrounding them on which with variable spacing with the help of transverse planks there are supports attached. In this case the length of the enclosure of each gear is the aliquant to the spacing of its advance.

  1. Droplets bouncing on a standing wave field

    Science.gov (United States)

    Pucci, Giuseppe; Tambasco, Lucas; Harris, Daniel; Bush, John

    2017-11-01

    A liquid bath subject to a vertical vibration becomes unstable to standing surface waves at a critical vibrational acceleration known as the Faraday threshold. We examine the behavior of a millimetric droplet bouncing on the surface of a quasi-one-dimensional fluid channel above the Faraday threshold. We identify a sequence of bifurcations that occurs as the vibrational acceleration is increased progressively, ultimately leading to the erratic, diffusive motion of the droplet along the length of the channel. A simple theoretical model is presented. This work was supported by the US National Science Foundation through Grants CMMI-1333242 and DMS-1614043.

  2. Construction of an automated table standing

    Science.gov (United States)

    Neira, R. E.; Barbero, M. D.; Di Giulio, E. A.; Folco, J. F.; Jiménez, G. F.

    2011-12-01

    In this paper, the construction of an upright stretcher designed for patients in rehabilitation. The standing back to patients' expectations of therapeutic improvement, allowing correct all the troubles of a passive long. It has been shown that this table favors not only physically but also has a psychological reach beyond the scope of physical therapy and strongly affects the recovery. At the same time, the use of an upright stretcher greatly decreases the biomechanical disorders of hospital staff in the process of recovery. Thus the problem of rehabilitation of trafficking in a comprehensive way which not only focuses on the patient's undivided attention but also includes medical and auxiliary personnel.

  3. Science stand-up at CERN

    CERN Multimedia

    Stephanie McClellan

    2013-01-01

    Supported by host Helen Keen from BBC4’s "It is Rocket Science", six amateur performers from CERN (Sam Gregson, Alex Brown, Benjamin Frisch, Claire Lee, Hugo Day and Clara Nellist) were joined on stage by geek-pop sensation Jonny Berliner and comedians Pierre Novellie and Lieven Scheire for a night of science stand-up comedy.   Host Helen Keen starts off the comedy event. (Image: Piotr Traczyk). Like the genesis of most great things, the LHComedy event began as an idea. Sam Gregson, a PhD student at CERN, had been a regular at the Cambridge Bright Club. This public engagement event promotes scientists’ research through stand-up comedy. Sam thought, “If people came to watch Bright Club at Cambridge and enjoyed the research, why can’t we do it at the biggest scientific experiment in the world?” Sam’s idea gained momentum after being introduced to FameLab participants at CERN. Similar to Bright Club, FameLab is a com...

  4. Standing Stability in Knee Osteoarthritis Patients

    Directory of Open Access Journals (Sweden)

    M.T. Karimi

    2016-09-01

    Full Text Available Aims: Being prevalent in the more than 40 years old persons, the knee osteoarthritis is one of the main factors in the function system failure mainly affecting their life. There is a type of instability in the persons with knee osteoarthritis, which is an increase in the domain and frequency of body pressure center. The aim of the present study was to compare the standing stability parameters in persons with knee osteoarthritis and healthy persons. Instrument & Methods: In this case-control, 15 patients with knee osteoarthritis referred to the physiotherapy clinic of the rehabilitation center and Al-Zahra hospital were studied in the muscle-skeletal research center of Isfahan University of Medical Sciences in 2015. The subjects were selected via stratified sampling method. As control group, 15 healthy persons were also studied in Isfahan. Total path length and the domain and frequency of pressure center in different directions were measured to assess the stability. Data was analyzed by SPSS 19 software using descriptive statistics and paired T test. Findings: There were increases in the mean movement domain and the frequency of pressure center in the anterior-posterior and the internal-external directions, as well as in the total path proceeded by the pressure center in the internal-external direction, in the persons with knee osteoarthritis than the healthy persons (p0.05. Conclusion: Standing stability and balance in persons with knee osteoarthritis decreases compared to healthy persons.

  5. Douglas-Fir Tussock Moth- and Douglas-Fir Beetle-Caused Mortality in a Ponderosa Pine/Douglas-Fir Forest in the Colorado Front Range, USA

    Directory of Open Access Journals (Sweden)

    José F. Negrón

    2014-12-01

    Full Text Available An outbreak of the Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough, occurred in the South Platte River drainage on the Pike-San Isabel National Forest in the Colorado Front Range attacking Douglas-fir, Pseudotsuga menziesii (Mirb. Franco. Stocking levels, species composition, and tree size in heavily and lightly defoliated stands were similar. Douglas-fir tussock moth defoliation resulted in significant Douglas-fir mortality in the heavily defoliated stands, leading to a change in dominance to ponderosa pine, Pinus ponderosa Lawson. Douglas-fir beetle, Dendroctonus pseudotsuqae Hopkins, populations increased following the defoliation event but caused less mortality, and did not differ between heavily and lightly defoliated stands. Douglas-fir tussock moth-related mortality was greatest in trees less than 15 cm dbh (diameter at 1.4 m above the ground that grew in suppressed and intermediate canopy positions. Douglas-fir beetle-related mortality was greatest in trees larger than 15 cm dbh that grew in the dominant and co-dominant crown positions. Although both insects utilize Douglas-fir as its primary host, stand response to infestation is different. The extensive outbreak of the Douglas-fir tussock moth followed by Douglas-fir beetle activity may be associated with a legacy of increased host type growing in overstocked conditions as a result of fire exclusion.

  6. Stand development patterns for young planted oak stands on bottomland hardwood restoration sites

    Science.gov (United States)

    Jonathan Stoll; Brent R. Frey

    2016-01-01

    Over the last several decades, bottomland restoration efforts have established hundreds of thousands of acres of planted hardwood stands throughout the Southeastern U.S. Much of the initial research focused on planting approaches and early growth and survival, contributing to more effective establishment methods. However, less research attention has been focused on...

  7. Transmission components of solar radiation in pine stands in relation to climatic and stand variables

    Science.gov (United States)

    Robert A. Muller

    1971-01-01

    In a new approach, transmission was studied by relating to stand biomass the ratio of incoming solar radiation beneath tree crowns to that within the atmosphere. Several assumptions were used to estimate analytically the various ways in which solar radiation penetrates through crowns of three pine species in northern California. Sunflecks accounted for much of the...

  8. Blood pressure associates with standing balance in elderly outpatients.

    Directory of Open Access Journals (Sweden)

    Jantsje H Pasma

    Full Text Available OBJECTIVES: Assessment of the association of blood pressure measurements in supine and standing position after a postural change, as a proxy for blood pressure regulation, with standing balance in a clinically relevant cohort of elderly, is of special interest as blood pressure may be important to identify patients at risk of having impaired standing balance in routine geriatric assessment. MATERIALS AND METHODS: In a cross-sectional cohort study, 197 community-dwelling elderly referred to a geriatric outpatient clinic of a middle-sized teaching hospital were included. Blood pressure was measured intermittently (n = 197 and continuously (subsample, n = 58 before and after a controlled postural change from supine to standing position. The ability to maintain standing balance was assessed during ten seconds of side-by-side, semi-tandem and tandem stance, with both eyes open and eyes closed. Self-reported impaired standing balance and history of falls were recorded by questionnaires. Logistic regression analyses were used to examine the association between blood pressure and 1 the ability to maintain standing balance; 2 self-reported impaired standing balance; and 3 history of falls, adjusted for age and sex. RESULTS: Blood pressure decrease after postural change, measured continuously, was associated with reduced ability to maintain standing balance in semi-tandem stance with eyes closed and with increased self-reported impaired standing balance and falls. Presence of orthostatic hypotension was associated with reduced ability to maintain standing balance in semi-tandem stance with eyes closed for both intermittent and continuous measurements and with increased self-reported impaired standing balance for continuous measurements. CONCLUSION: Continuous blood pressure measurements are of additional value to identify patients at risk of having impaired standing balance and may therefore be useful in routine geriatric care.

  9. Sizing stand-alone photovoltaic systems

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available A method of sizing stand-alone photovoltaic systems regarding the reliability to satisfy the load demand, economy of components, and discharge depth exploited by the batteries is presented in this work. Solar radiation data simulated by an appropriate stochastic time series model, and not actual measurements, are used in the sizing procedure. This offers two distinct advantages: (a sizing can be performed even for locations where no actual data exist, (b the influence of the variation of the statistical parameters of solar radiation in sizing can be examined. The method has been applied and tested for several representative locations all over Greece for which monthly daily average values of solar radiation are given by ELOT (Hellenic Organization of Standardization.

  10. 2014 Sensorimotor Risk Standing Review Panel

    Science.gov (United States)

    Steinberg, Susan

    2014-01-01

    The Sensorimotor Risk Standing Review Panel (from here on referred to as the SRP) met on December 17 - 18, 2014 in Houston, TX to review the current status of the Risk of Impaired Control of Spacecraft, Associated Systems and Immediate Vehicle Egress due to Vestibular/Sensorimotor Alteration Associated with Space Flight (Sensorimotor Risk) in the Integrated Research Plan (IRP). During the meeting, the SRP received an in-depth briefing of the current status of the Sensorimotor Risk from Dr. Jacob Bloomberg, the Human Research Program (HRP) Sensorimotor Discipline Lead Scientist and Dr. Millard Reschke, the Chief Scientist of the Neuroscience Laboratories at the NASA Johnson Space Center (JSC). The SRP was impressed with the information that Dr. Bloomberg and Dr. Reschke presented and think that the in-person meeting (instead of WebEx/teleconference) allowed for more interactive and thoughtful conversations.

  11. Standing variation in spatially growing populations

    Science.gov (United States)

    Fusco, Diana; Gralka, Matti; Kayser, Jona; Hallatschek, Oskar

    Patterns of genetic diversity not only reflect the evolutionary history of a species but they can also determine the evolutionary response to environmental change. For instance, the standing genetic diversity of a microbial population can be key to rescue in the face of an antibiotic attack. While genetic diversity is in general shaped by both demography and evolution, very little is understood when both factors matter, as e.g. for biofilms with pronounced spatial organization. Here, we quantitatively explore patterns of genetic diversity by using microbial colonies and well-mixed test tube populations as antipodal model systems with extreme and very little spatial structure, respectively. We find that Eden model simulations and KPZ theory can remarkably reproduce the genetic diversity in microbial colonies obtained via population sequencing. The excellent agreement allows to draw conclusions on the resilience of spatially-organized populations and to uncover new strategies to contain antibiotic resistance.

  12. FERMILAB CRYOMODULE TEST STAND RF INTERLOCK SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Troy [Fermilab; Diamond, J. S. [Fermilab; McDowell, D. [Fermilab; Nicklaus, D. [Fermilab; Prieto, P. S. [Fermilab; Semenov, A. [Fermilab

    2016-10-12

    An interlock system has been designed for the Fermilab Cryo-module Test Stand (CMTS), a test bed for the cryo- modules to be used in the upcoming Linac Coherent Light Source 2 (LCLS-II) project at SLAC. The interlock system features 8 independent subsystems, one per superconducting RF cavity and solid state amplifier (SSA) pair. Each system monitors several devices to detect fault conditions such as arcing in the waveguides or quenching of the SRF system. Additionally each system can detect fault conditions by monitoring the RF power seen at the cavity coupler through a directional coupler. In the event of a fault condition, each system is capable of removing RF signal to the amplifier (via a fast RF switch) as well as turning off the SSA. Additionally, each input signal is available for re- mote viewing and recording via a Fermilab designed digitizer board and MVME 5500 processor.

  13. Confining standing waves in optical corrals.

    Science.gov (United States)

    Babayan, Yelizaveta; McMahon, Jeffrey M; Li, Shuzhou; Gray, Stephen K; Schatz, George C; Odom, Teri W

    2009-03-24

    Near-field scanning optical microscopy images of solid wall, circular, and elliptical microscale corrals show standing wave patterns confined inside the structures with a wavelength close to that of the incident light. The patterns inside the corrals can be tuned by changing the size and material of the walls, the wavelength of incident light, and polarization direction for elliptical corrals. Finite-difference time-domain calculations of the corral structures agree with the experimental observations and reveal that the electric and magnetic field intensities are out of phase inside the corral. A theoretical modal analysis indicates that the fields inside the corrals can be attributed to p- and s-polarized waveguide modes, and that the superposition of the propagating and evanescent modes can explain the phase differences between the fields. These experimental and theoretical results demonstrate that electromagnetic fields on a dielectric surface can be controlled in a predictable manner.

  14. Stand dynamics in 60-year-old Allegheny hardwoods after thinning

    Science.gov (United States)

    Gary W. Miller

    1997-01-01

    Stand dynamics and tree growth in even-aged hardwood stands can be influenced by manipulating relative stand density, species composition, and stand structure. Land managers need quantitative information on the effect of vegetation manipulation to prescribe stand treatments that are appropriate for specific management objectives. Sixty-year-old stands composed of black...

  15. Factors Related to Standing Balance in Patients With Knee Osteoarthritis

    OpenAIRE

    Park, Hye Jeong; Ko, Saebyuk; Hong, Hyeon Mi; Ok, Eunjae; Lee, Jong In

    2013-01-01

    Objective To assess factors related to standing balance in patients with knee osteoarthritis (OA). Methods In total, 37 female patients with painful knee OA were included. Pain, knee alignment, and Kellgren and Lawrence grade were evaluated accordingly. Static standing balance was measured with a force-platform system under two different conditions: static standing with eyes open (EO) and eyes closed (EC) for 30 seconds. The mean speed (mm/s) of movement of the center of pressure in the anter...

  16. Disturbance and Stand Development of a Colorado Subalpine Forest

    OpenAIRE

    Veblen, Thomas T.; Hadley, Keith S; Reid, Marion S

    1991-01-01

    Stand development patterns were examined in an Engelmann spruce (Picea engelmannii), subalpine fir (Abies lasiocarpa) and lodgepole pine (Pinus contorta var. latifolia) forest in Rocky Mountain National Park in northern Colorado. Two old-growth stands (with fine-scale windthrows dominating dynamics) and a 260-yr-old post-fire stand were sampled for tree ages, sizes, growth, and replacement patterns in windthrow gaps. Visual assessment of frequency of growth releases in increment cores, and de...

  17. Carbon stock in topsoil, standing floor litter and above ground ...

    African Journals Online (AJOL)

    Above ground biomass (ABG) and carbon stock were significantly (p=0.003 and p=0.0001) higher in the plantation, the order is ABG > soil > standing floor leaf litter > standing floor wood litter. Soil C stock varies from 10.47 t ha-1 in the plantation to 10.58 t ha-1 C in the forest. Above ground biomass, standing leaf and wood ...

  18. Optimized design for sling of stand up lift

    Science.gov (United States)

    Xu, Dongfang; Wang, Yue; Cui, Tengfei; Bao, Xuelian; Duan, Xingguang

    2017-04-01

    Stand up lift is a kind of equipment that assists those with dyskinesia of legs to stand up or move. As an important part of stand up lift, sling concerns the realization of the equipment's function and the safety of users. On the basis of ergonomics theory, this thesis will design and optimize the sling to make it safer and more comfortable and meet demands of different people.

  19. Biomass expansion factors for Eucalyptus globulus stands in Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Soares, P.; Tome, M.

    2012-11-01

    One of several procedures for estimating carbon stocks in forests is the estimation of tree or stand biomass based on forest inventory data. The two approaches normally used to convert field measurements of trees to stand biomass values are allometric biomass equations and biomass expansion factors (BEFs). BEFs are used in published National Forest Inventory results in which biomass is not estimated or as a complement of growth models that do not include biomass predictions. In this paper, the effectiveness of BEFs for estimating total stand biomass in Portuguese Eucalyptus globulus plantations was analyzed. Here, BEF is defined as the ratio of total stand biomass (aboveground biomass plus root biomass) to stand volume with bark. To calculate total biomass, an equation was developed to estimate root biomass as a function of aboveground biomass. Changes of BEF with stand variables were analyzed. Strong relationships were observed between BEF and stand age, stand basal area, stand volume and dominant height. Consequently, an equation to predict BEF as a function of stand variables was fitted, and dominant height was selected as the predictor stand variable. Estimates of total stand biomass based on individual tree allometric equations were compared with estimates obtained with a constant BEF (0.77), used in the Portuguese National Inventory Report on Greenhouse Gases, and with estimates obtained using the dominant height-dependent BEF equation developed in this work. The BEF prediction model proposed in this work may be used to improve E. globulus Portuguese biomass estimates when tree allometric equations cannot be used. (Author) 40 refs.

  20. Wildlife response to stand structure of deciduous woodlands

    Science.gov (United States)

    Robert A. Hodorff; Carolyn Hull Sieg; Raymond L. Linder

    1988-01-01

    Deciduous woodlands provide important habitat for wildlife but comprise Fraxinus pennsylvanica) woodlands in northwestern South Dakota. Closed-canopy stands were multilayered communities with dense...

  1. The role of forest stand structure as biodiversity indicator

    DEFF Research Database (Denmark)

    Gao, Tian; Hedblom, Marcus; Emilsson, Tobias

    2014-01-01

    species composition and canopy stratification. Using data from the National Inventory of Landscapes in Sweden and General Linear Mixed Model, plant species diversity (Shannon diversity index, SHDI) and composition (Sørensen-Dice index, SDI) were tested between 26 different stand structure types and nine...... be achieved if indicators are derived from existing data. In this study, a model for classifying forest stand structures was developed and tested as an indicator of overall plant species diversity at stand level. The model combines four stand structure parameters: canopy coverage, age of canopy trees, tree...

  2. Flexible integration of free-standing nanowires into silicon photonics.

    Science.gov (United States)

    Chen, Bigeng; Wu, Hao; Xin, Chenguang; Dai, Daoxin; Tong, Limin

    2017-06-14

    Silicon photonics has been developed successfully with a top-down fabrication technique to enable large-scale photonic integrated circuits with high reproducibility, but is limited intrinsically by the material capability for active or nonlinear applications. On the other hand, free-standing nanowires synthesized via a bottom-up growth present great material diversity and structural uniformity, but precisely assembling free-standing nanowires for on-demand photonic functionality remains a great challenge. Here we report hybrid integration of free-standing nanowires into silicon photonics with high flexibility by coupling free-standing nanowires onto target silicon waveguides that are simultaneously used for precise positioning. Coupling efficiency between a free-standing nanowire and a silicon waveguide is up to ~97% in the telecommunication band. A hybrid nonlinear-free-standing nanowires-silicon waveguides Mach-Zehnder interferometer and a racetrack resonator for significantly enhanced optical modulation are experimentally demonstrated, as well as hybrid active-free-standing nanowires-silicon waveguides circuits for light generation. These results suggest an alternative approach to flexible multifunctional on-chip nanophotonic devices.Precisely assembling free-standing nanowires for on-demand photonic functionality remains a challenge. Here, Chen et al. integrate free-standing nanowires into silicon waveguides and show all-optical modulation and light generation on silicon photonic chips.

  3. The experiences of mastery of stand-by energy demand; Les experiences de MDE stand by

    Energy Technology Data Exchange (ETDEWEB)

    Schilken, P.

    2001-07-01

    In the residential sector of the OECD countries, the electricity losses of domestic appliances in stand-by position represent 1.5% of the total electricity consumption. This study belongs to the SAVE project (pilot campaign of municipal utilities for an improved rational use of energy). Its aim is to observe the policies and experiments implemented by municipalities and municipal energy companies for the abatement of the electricity consumptions of stand-by origin. A working group consisting of the German Stadtwerke and some international partners have debated the possible actions and documents for an efficient information of the public. This document presents the brochures and local actions of this program. (J.S.)

  4. Using a stand-level model to predict light absorption in stands with vertically and horizontally heterogeneous canopies

    Directory of Open Access Journals (Sweden)

    David I Forrester

    2014-09-01

    Full Text Available Background Forest ecosystem functioning is strongly influenced by the absorption of photosynthetically active radiation (APAR, and therefore, accurate predictions of APAR are critical for many process-based forest growth models. The Lambert-Beer law can be applied to estimate APAR for simple homogeneous canopies composed of one layer, one species, and no canopy gaps. However, the vertical and horizontal structure of forest canopies is rarely homogeneous. Detailed tree-level models can account for this heterogeneity but these often have high input and computational demands and work on finer temporal and spatial resolutions than required by stand-level growth models. The aim of this study was to test a stand-level light absorption model that can estimate APAR by individual species in mixed-species and multi-layered stands with any degree of canopy openness including open-grown trees to closed canopies. Methods The stand-level model was compared with a detailed tree-level model that has already been tested in mixed-species stands using empirical data. Both models were parameterised for five different forests, including a wide range of species compositions, species proportions, stand densities, crown architectures and canopy structures. Results The stand-level model performed well in all stands except in the stand where extinction coefficients were unusually variable and it appears unlikely that APAR could be predicted in such stands using (tree- or stand-level models that do not allow individuals of a given species to have different extinction coefficients, leaf-area density or analogous parameters. Conclusion This model is parameterised with species-specific information about extinction coefficients and mean crown length, diameter, height and leaf area. It could be used to examine light dynamics in complex canopies and in stand-level growth models.

  5. Stiffness control of balance in quiet standing.

    Science.gov (United States)

    Winter, D A; Patla, A E; Prince, F; Ishac, M; Gielo-Perczak, K

    1998-09-01

    Our goal was to provide some insights into how the CNS controls and maintains an upright standing posture, which is an integral part of activities of daily living. Although researchers have used simple performance measures of maintenance of this posture quite effectively in clinical decision making, the mechanisms and control principles involved have not been clear. We propose a relatively simple control scheme for regulation of upright posture that provides almost instantaneous corrective response and reduces the operating demands on the CNS. The analytic model is derived and experimentally validated. A stiffness model was developed for quiet standing. The model assumes that muscles act as springs to cause the center-of-pressure (COP) to move in phase with the center-of-mass (COM) as the body sways about some desired position. In the sagittal plane this stiffness control exists at the ankle plantarflexors, in the frontal plane by the hip abductors/adductors. On the basis of observations that the COP-COM error signal continuously oscillates, it is evident that the inverted pendulum model is severely underdamped, approaching the undamped condition. The spectrum of this error signal is seen to match that of a tuned mass, spring, damper system, and a curve fit of this "tuned circuit" yields omega n the undamped natural frequency of the system. The effective stiffness of the system, Ke, is then estimated from Ke = I omega n2, and the damping B is estimated from B = BW X I, where BW is the bandwidth of the tuned response (in rad/s), and I is the moment of inertia of the body about the ankle joint. Ten adult subjects were assessed while standing quietly at three stance widths: 50% hip-to-hip distance, 100 and 150%. Subjects stood for 2 min in each position with eyes open; the 100% stance width was repeated with eyes closed. In all trials and in both planes, the COP oscillated virtually in phase (within 6 ms) with COM, which was predicted by a simple 0th order spring

  6. RAMSES stands guard over the accelerator chain

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    RAMSES, the system that is used to monitor radiation at the LHC, CNGS, CTF3 and n-TOF facilities, will soon be installed at strategic points in the accelerator chain, replacing the older monitoring system ARCON. The replacement programme has already begun.   RAMSES (which stands for “Radiation Monitoring System for the Environment and Safety”) is designed to protect workers, the general public and the environment, both on the Organization’s site and in the surrounding areas. It is currently operational on all the LHC sites and at CTF3, CNGS and n-TOF, while the remaining sites are still equipped with the ARCON (Area CONtroller) system. Daniel Perrin, head of the Instrumentation and Logistics Section of the HSE Unit's Radiation Protection Group, explains: “ARCON was designed for the old LEP accelerator and dates back to the early 1980s, while RAMSES is a much more recent design intended specifically for the LHC. With 389 detectors distributed across 124 mea...

  7. Introduction to "Standing together in Troubled Times"

    CERN Document Server

    Shifman, M

    2016-01-01

    This Introduction opens the book {\\sl Standing Together in Troubled Times} which presents a story of friendship between Wolfgang Pauli, one of the greatest theoretical physicists of the 20th century, and Charlotte Houtermans. They met at the very onset of the quantum era, in the late 1920s in Germany where Charlotte was a physics student at G\\"ottingen University. At that time G\\"ottingen was right at the heart of groundbreaking developments in physics. Both Pauli and Houtermans personally knew major participants in the quantum revolution. Caught between two evils -- German National Socialism and Soviet Communism -- Charlotte Houtermans would have likely perished if it were not for the brotherhood of physicists: Niels Bohr, Wolfgang Pauli, Albert Einstein, James Franck, Max Born, Robert Oppenheimer and many other noted scientists who tried to save friends and colleagues (either leftist sympathizers or Jews) who were in mortal danger of becoming entrapped in a simmering pre-WWII Europe. This book is based on n...

  8. Immunoassay on Free-standing Electrospun Membranes

    Science.gov (United States)

    Steckl, Andrew; Wu, Dapeng; Han, Daewoo

    2010-03-01

    For the purpose of immunoassay, electrospun membranes can be thought as the thread-like self-assembling of nano/microbeads. Non-woven membranes of electrospun poly(caprolactone) (PCL) fibers display excellent tenacity, flexibility and suitable surface energy. These PCL membranes exhibit easy handling in air, fast spreading and wetting in aqueous solution, and rapid adsorption of protein molecules by hydrophobic interaction. After a fold-and-press process, the membrane porosity was reduced from ˜ 75% to less than 10%, while the thickness increased from ˜5 to 300 μm. The resulting fluorescence signal from adsorbed protein increased more than 120 times. With anti-HSA and HSA-FITC as an immunoassay model, a linear detection range from 500 ng/mL down to 1 ng/mL is obtained, with a detection of limit (LOD) of ˜ 0.08 ng/mL. By comparison, conventional nitrocellulose and thicker PCL fiber electrospun membrane displayed a much higher LOD of ˜100 ng/mL. Immunoassay on free-standing electrospun membrane successfully combines the low-cost and simplicity of conventional membrane immunoassay, with the fast reaction speed and high sensitivity characteristic of magnetic nano/microbeads bioassays.

  9. Immunoassay on free-standing electrospun membranes.

    Science.gov (United States)

    Wu, Dapeng; Han, Daewoo; Steckl, Andrew J

    2010-01-01

    For the purpose of immunoassay, electrospun membranes can be thought as the threadlike self-assembling of nano/microbeads. Nonwoven membranes of electrospun poly(epsilon-caprolactone) (PCL) fibers display excellent tenacity, flexibility and suitable surface energy. These PCL membranes exhibit easy handling in air, fast spreading, and wetting in aqueous solution, and rapid adsorption of protein molecules by hydrophobic interaction. After a fold-and-press process, the membrane porosity was reduced from approximately 75% to less than 10%, whereas the thickness increased from 5.3 to 280 microm. The resulting fluorescence signal from adsorbed protein increased>120x. With anti-HSA and HSA-FITC as an immunoassay model, a linear detection range from 500 ng/mL down to 1 ng/mL is obtained, with a detection of limit (LOD) of approximately 0.08 ng/mL. By comparison, conventional nitrocellulose and a 24.3 microm PCL fiber electrospun membrane displayed a much higher LOD of approximately 100 ng/mL. Immunoassay on free-standing electrospun membrane successfully combines the low-cost and simplicity of conventional membrane immunoassay, with the fast reaction speed and high sensitivity characteristic of magnetic nano/microbeads bioassays.

  10. Visual evoked responses during standing and walking

    Directory of Open Access Journals (Sweden)

    Klaus Gramann

    2010-10-01

    Full Text Available Human cognition has been shaped both by our body structure and by its complex interactionswith its environment. Our cognition is thus inextricably linked to our own and others’ motorbehavior. To model brain activity associated with natural cognition, we propose recording theconcurrent brain dynamics and body movements of human subjects performing normal actions.Here we tested the feasibility of such a mobile brain/body (MoBI imaging approach byrecording high-density electroencephalographic (EEG activity and body movements of subjectsstanding or walking on a treadmill while performing a visual oddball response task. Independentcomponent analysis (ICA of the EEG data revealed visual event-related potentials (ERPs thatduring standing, slow walking, and fast walking did not differ across movement conditions,demonstrating the viability of recording brain activity accompanying cognitive processes duringwhole body movement. Non-invasive and relatively low-cost MoBI studies of normal, motivatedactions might improve understanding of interactions between brain and body dynamics leadingto more complete biological models of cognition.

  11. Harvesting systems for western stand health improvement cuttings

    Science.gov (United States)

    Bruce R. Hartsough; Bryce J. Stokes; Joseph F. McNeel; William F. Watson

    1995-01-01

    A significant percentage of the forested area in the western United States is comprised of stands that have been altered over time by human activities, especially fire suppression, and are now being damaged by droughts, insect attacks, and wildfires. These stands should be returned to a condition where "biotic and abiotic influences do not threaten resource...

  12. A whole stand basal area projection model for Appalachian hardwoods

    Science.gov (United States)

    John R. Brooks; Lichun Jiang; Matthew Perkowski; Benktesh Sharma

    2008-01-01

    Two whole-stand basal area projection models were developed for Appalachian hardwood stands. The proposed equations are an algebraic difference projection form based on existing basal area and the change in age, trees per acre, and/or dominant height. Average equation error was less than 10 square feet per acre and residuals exhibited no irregular trends.

  13. Heavy thinning of ponderosa pine stands: An Arizona case study

    Science.gov (United States)

    Peter F. Ffolliott; Jr. Baker; Gerald J. Gottfried

    2000-01-01

    Growth and structural changes in a mosaic of even-aged ponderosa pine (Pinus ponderosa) stands were studied for 25 years to determine the long-term impacts of a heavy thinning treatment to a basal-area level of 25 ft2/acre. Basal area and volume growth of these stands has increased since thinning and likely will continue to...

  14. Guide to the Stand-Damage Model interface management system

    Science.gov (United States)

    George Racin; J. J. Colbert

    1995-01-01

    This programmer's support document describes the Gypsy Moth Stand-Damage Model interface management system. Management of stand-damage data made it necessary to define structures to store data and provide the mechanisms to manipulate these data. The software provides a user-friendly means to manipulate files, graph and manage outputs, and edit input data. The...

  15. Flooding effects on stand development in cypress-tupelo

    Science.gov (United States)

    Richard F. Keim; Thomas J. Dean; Jim L. Chambers

    2013-01-01

    The effects of inundation on growth of cypress (Taxodium spp.) and tupelo (Nyssa spp.) trees have been extensively researched, but conclusions are often complicated by attendant effects on stand development. Flooding affects development of cypress-tupelo stands by limiting seedling germination and survival, truncating species...

  16. Evaluation of three classifiers in mapping forest stand types using ...

    African Journals Online (AJOL)

    Three classifiers were examined for their suitability in mapping the different forest stand types in the area (maximum likelihood, spectral angle mapper and decision tree). The results showed that using maximum likelihood classifier and ASTER imagery, different forest stand types can be accurately mapped with an overall ...

  17. Ampere hour method of sizing a stand alone photovoltaic system ...

    African Journals Online (AJOL)

    Stand-alone photovoltaic power systems are natural options for application in electrification of remote areas which are not served by the grid electricity supply system. An ampere-hour method of sizing a stand-alone PV system for application in any remote location has been presented. The design which is for both ac and dc ...

  18. 'Covering doctors' standing in for unavailable colleagues: What is ...

    African Journals Online (AJOL)

    'Covering doctors' standing in for unavailable colleagues: What is the legal position? D.J. McQuoid-Mason. Abstract. Covering doctors are those who stand in for colleagues when the latter are unable to deal with their patients. Covering doctors who begin to issue telephonic instructions to nurses or other healthcare ...

  19. Rapid economic analysis of northern hardwood stand improvement options

    Science.gov (United States)

    William B. Leak

    1980-01-01

    Data and methodology are provided for projecting basal area, diameter, volumes, and values by product for northern hardwood stands, and for determining the rate of return on stand improvement investments. The method is rapid, requires a minimum amount of information, and should prove useful for on-the-ground economic analyses.

  20. "Growing trees backwards": Description of a stand reconstruction model

    Science.gov (United States)

    Jonathan D. Bakker; Andrew J. Sanchez Meador; Peter Z. Fule; David W. Huffman; Margaret M. Moore

    2008-01-01

    We describe an individual-tree model that uses contemporary measurements to "grow trees backward" and reconstruct past tree diameters and stand structure in ponderosa pine dominated stands of the Southwest. Model inputs are contemporary structural measurements of all snags, logs, stumps, and living trees, and radial growth measurements, if available. Key...

  1. Wood volume distribution as an indicatorof stand homogeneity

    Directory of Open Access Journals (Sweden)

    Vučković Milivoj

    2006-01-01

    Full Text Available The results of stand homogeneity definition are analyzed based on the percentage ratio of the distribution of tree number and the distribution of volume per diameter degrees. Homogeneity is defined based on homogeneity index (H and Lorenz’s curve. Homogeneous stand is the hypothetical stand whose trees have equal volumes. Real stands, depending on their silvicultural form and treatment, as well as the development stage, are more or less distant from the absolutely homogenous state. The effect of the diameter degree width on the accuracy of homogeneity index calculation was determined and the possibility of applying the homogeneity index as an additional parameter for the assessment of site quality of selection stands was analyzed.

  2. Size-structure dynamics of mixed versus pure forest stands

    Directory of Open Access Journals (Sweden)

    Hans Pretzsch

    2014-12-01

    Full Text Available Mixed species forests are presently on the advance and widely held to provide many ecosystem functions and services better than pure stands. Recent studies well explored species mixing effects at the individual tree or stand level. However, the link between individual and stand level which is represented by the size-structure dynamics of stands, is still hardly understood.Aim of this study: The objective was to analyse how species mixing modifies the size-structure dynamics of mixed compared with pure forest stands. Area of the study: the study was carried out in Southern Germany.Material and Methods: We selected 11long-term experiments comprising 129 plots of un-thinned or just lightly thinned pure and mixed stands of European beech (Fagus sylvatica [ L.] and analysed their size structure dynamics.Main Results: Based on the Gini coefficient, skewness and kurtosis we show how mixing with Norway spruce (Picea abies [L.] Karst and sessile oak (Quercus petraea (Matt. Liebl. modifies the size-structure dynamics of European beech. The size distribution of beech in mixture mostly lags behind the pure stand, is more size-asymmetric, and the mortality shifts from the smaller diameter classes further to the taller trees than in pure stands.Research highlights: The revealed changes of the size-structure dynamics of beech in mixed versus pure stands result from a modification of both growth partitioning and self-thinning. We draw conclusions of the reduced size growth and size equality of beech in mixed versus pure stands for forest management planning and perspectives for forest research.Keywords: species selection effect; true mixing effect; morphological plasticity; size-distribution; growth partitioning between trees; mode of mortality; European beech (Fagus sylvatica [L.]; Norway spruce (Picea abies [L.] Karst; sessile oak (Quercus petraea (Matt. Liebl..

  3. Stand Structure and Composition 32 Years after Precommercial Thinning Treatments in a Mixed Northern Conifer Stand in Central Maine

    Science.gov (United States)

    Aaron R. Weiskittel; Laura S. Kenefic; Rongxia Li; John Brissette

    2011-01-01

    The effects of four precommercial thinning (PCT) treatments on an even-aged northern conifer stand in Maine were investigated by examining stand structure and composition 32 years after treatment. Replicated treatments applied in 1976 included: (1) control (no PCT), (2) row thinning (rowthin; 5-ft-wide row removal with 3-ft-wide residual strips), (3) row thinning with...

  4. Comparing violinists' body movements while standing, sitting, and in sitting orientations to the right or left of a music stand.

    Science.gov (United States)

    Spahn, Claudia; Wasmer, Céline; Eickhoff, Franziska; Nusseck, Manfred

    2014-06-01

    For violinists, it is common practice to play while standing or sitting. When playing in an orchestra, generally two persons share one music stand, with one sitting to the right and the other to the left of the stand. The present study investigated specific movement patterns while playing in these different positions. Using a posturographic device and 3D motion capture, the body weight distributions and specific body movements of 19 violinists were analyzed. Results showed unbalanced weight distributions while sitting in front of or oriented to the right of the music stand compared to the almost even distributions while standing or oriented to the left of the stand. Analyses of movement patterns showed significant differences between standing and sitting, mainly in the upper body parts with less movability while sitting. While sitting in front of or oriented to the right of the music stand, the right bowing arm showed more restricted movements compared to other positions. The playing positions are discussed with regard to possible physiological stress and health risks. The study emphasizes the importance of different playing positions and offers starting points for discussion of postural influences and sensible handling of the instrument in performance and practice for violinists.

  5. Regulating Stand Density by Precommercial Thinning in Naturally Regenerated Loblolly Pine Stands: Evaluation of Management and Economic Opportunities

    Science.gov (United States)

    David J. Moorhead; Coleman W. Dangerfield; M. Boyd Edwards

    1997-01-01

    The economic performance of converting 13-year-old, overstocked (>3,000 trees per acre), naturally regenerated pine stands using precommercial thinning at a cost of $140 per acre was modeled for 25-, 35-, and 50-year rotations. The stand density was reduced to 283 trees per acre. Subsequent management scenarios recovered establishment and management costs through...

  6. Effects of stand and inter-specific stocking on maximizing standing tree carbon stocks in the eastern United States

    Science.gov (United States)

    Christopher W. Woodall; Anthony W. D' Amato; John B. Bradford; Andrew O. Finley

    2011-01-01

    There is expanding interest in management strategies that maximize forest carbon (C) storage to mitigate increased atmospheric carbon dioxide. The tremendous tree species diversity and range of stand stocking found across the eastern United States presents a challenge for determining optimal combinations for the maximization of standing tree C storage. Using a...

  7. Plant growth regulators to manipulate oat stands

    Directory of Open Access Journals (Sweden)

    A. RAJALA

    2008-12-01

    Full Text Available Plant growth regulators (PGRs are exogenously applied chemicals that alter plant metabolism, cell division, cell enlargement, growth and development by regulating plant hormones or other biological signals. For example, some PGRs regulate stem elongation by inhibiting biosynthesis of gibberellins or through releasing ethylene. PGR effects are widely studied and reported on barley (Hordeum vulgare L. and wheat (Triticum aestivum L., whereas there are only a few reports addressing oat (Avena sativa L.. This is likely to be a result of smaller acreage and lower intensity of oat management and production and hence a reduced need for stem shortening by PGRs. However, this is not the case for all cereal producing regions and there exists a need to understand the potential application of PGRs to oat production. This paper represents a review of the potential of PGRs to regulate stem elongation and other biological traits governing plant stand structure and yield components, with special emphasis on oat and its responses to PGRs. Yield improvement requires more heads per unit land area, more grains per head or heavier grains. Of these yield-determining parameters, the number of head bearing tillers and grain numbers per head, compared with grain weight, are more likely to be improved by PGR application. In the absence of lodging, PGR may reduce grain yield due to potential reduction in mean grain weight and/or grain number. Cultivation systems aiming at extensive yields with intensive use of inputs likely benefit from PGR applications more often compared with low or moderate input cultivation, for which cost effectiveness of PGRs is not frequently reached.;

  8. Financial Village Standing in Indonesian Financial System

    Directory of Open Access Journals (Sweden)

    Herry Purnomo

    2015-12-01

    Full Text Available Financial resources of the village that are sourced from a country or a Regional Finance Financial based Law Number 6 Year 2014 of The Village is the mandate of the law that must be allocated to the village. The interconnectedness of the financial position of the village in the financial system of the country or Region concerned the Financial administrative and territorial relations, and there is no setting directly regarding the finances of the village as part of the financial system of the country or the financial area. In respect of the elements of the crime of corruption deeds against financial irregularities of the village there are still disagreements on the interpretation of the law in trapping the perpetrators of corruption on the village chief that implies not satisfy the principle of legality and legal certainty in the ruling of the matter of financial irregularities. In fact, many of the village chief or Councilor caught the criminal offence of corruption over the use of financial irregularities. This research analyzes How the financial position of the village in the financial system of the country or region, as well as whether the financial resources of the village is derived from the state budget or region budget managed in village budget belongs to the category of village finances and whether tort against the financial management of the village can be categorized as a criminal act corruption. How To Cite: Purnomo, H. (2015. Financial Village Standing in Indonesian Financial System. Rechtsidee, 2(2, 121-140. doi:http://dx.doi.org/10.21070/jihr.v2i2.81

  9. The experiences of MDE stand-by; Les experiences de MDE stand-by

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-02-01

    The control of the electric power demand (MDE) is a worrying subject for many countries. The consumption of the electrical equipment in stand-by, is evaluated at 20 TWh/year for the ternary and residential sectors in Germany and 5,3 in France. Taking into account the SAVE project (Pilot campaign of municipal utilities for an improved rational use of energy), this study aims to observe the policies and the experiences of local governments in terms of energy consumption reduction. (A.L.B.)

  10. Log and lumber grades as indicators of wood quality in 20- to 100-year-old Douglas-fir trees from thinned and unthinned stands.

    Science.gov (United States)

    R. James Barbour; Dean L. Parry

    2001-01-01

    This report examines the differences in wood characteristics found in coastal Pacific Northwest Douglas-fir (Pseudotsuga mensziesii (Mirb.) Franco) trees harvested at the age of 70 to 100 years old to wood characteristics of trees harvested at the age of 40 to 60 years. Comparisons of differences in domestic log grades suggest that the proportion...

  11. StandsSIM-MD: a Management Driven forest SIMulator

    Energy Technology Data Exchange (ETDEWEB)

    Barreiro, S.; Rua, J.; Tomé, M.

    2016-07-01

    Aim of the study. The existing stand level forest simulators available in Portugal were not developed with the aim of including up-to-date model versions and were limited in terms of accounting for forest management. The simulators’ platform, sIMfLOR was recently created to implement different growth models with a common philosophy. The objective was developing one easily-updatable, user-friendly, forest management and climate change sensitive simulator capable of projecting growth for the main tree species in Portugal. Area of the study: Portugal. Material and methods: The new simulator was programmed in a modular form consisting of several modules. The growth module integrates different forest growth and yield models (empirical and process-based) for the main wood production tree species in Portugal (eucalypt, umbrella and maritime pines); whereas the management module drives the growth projections along the planning horizon according to a range of forest management approaches and climate (at present only available for eucalypt). Main results: The main result is the StandsSIM-MD Management Driven simulator that overcomes the limitations of the existing stand level simulators. It is a step forward when compared to the models currently available in the sIMfLOR platform covering more tree species, stand structures and stand compositions. It is focused on end-users and it is based on similar concepts regarding the generation of required inputs and generated outputs. Research highlights: Forest Management Driven simulations approach. Multiple Prescriptions-Per-Stand functionality. StandsSIM-MD can be used to support landowners decisions on stand forest management. StandsSIM-MD simulations at regional level can be combined with optimization routines. (Author)

  12. Stand for testing the electrical race car engine

    Science.gov (United States)

    Baier, M.; Franiasz, J.; Mierzwa, P.; Wylenzek, D.

    2015-11-01

    An engine test stand created especially for research of electrical race car is described in the paper. The car is an aim of Silesian Greenpower project whose participants build and test electrical vehicles to take part in international races in Great Britain. The engine test stand is used to test and measure the characteristics of vehicles and their engines. It has been designed particularly to test the electric cars engineered by students of Silesian Greenpower project. The article contains a description how the test stand works and shows its versatility in many areas. The paper presents both construction of the test stand, control system and sample results of conducted research. The engine test stand was designed and modified using PLM Siemens NX 8.5. The construction of the test stand is highly modular, which means it can be used both for testing the vehicle itself or for tests without the vehicle. The test stand has its own wheel, motor, powertrain and braking system with second engine. Such solution enables verifying various concepts without changing the construction of the vehicle. The control system and measurement system are realized by enabling National Instruments product myRIO (RIO - Reconfigurable Input/Output). This controller in combination with powerful LabVIEW environment performs as an advanced tool to control torque and speed simultaneously. It is crucial as far as the test stand is equipped in two motors - the one being tested and the braking one. The feedback loop is realized by an optical encoder cooperating with the rotor mounted on the wheel. The results of tests are shown live on the screen both as a chart and as single values. After performing several tests there is a report generated. The engine test stand is widely used during process of the Silesian Greenpower vehicle design. Its versatility enables powertrain testing, wheels and tires tests, thermal analysis and more.

  13. Electromagnetic calibration system for sub-micronewton torsional thrust stand

    Science.gov (United States)

    Lam, J. K.; Koay, S. C.; Cheah, K. H.

    2017-12-01

    It is critical for a micropropulsion system to be evaluated. Thrust stands are widely recognised as the instrument to complete such tasks. This paper presents the development of an alternative electromagnetic calibration technique for thrust stands. Utilising the commercially made voice coils and permanent magnets, the proposed system is able to generate repeatable and also consistent steady-state calibration forces at over four orders of magnitude (30 – 23000 μN). The system is then used to calibrate a custom-designed torsional thrust stand, where its inherent ability in ease of setup is well demonstrated.

  14. Thrust stand for high-power electric propulsion devices

    Science.gov (United States)

    Haag, T. W.

    1991-01-01

    This paper describes a new high-power thrust stand developed for use with high-power (up to 250 kW) magnetoplasmadynamic (MPD) thrusters, which is installed in a high-vacuum MPD facility at Lewis Research Center. The design of the stand is based on inverted pendulum configuration, with the result of large displacements and high resolution. Calibration results showed that thrust measurements were linear and repeatable to within a fraction of 1 percent. The thrust stand was used for testing water-cooled MPD thrusters at power levels up to 125 kW. The thruster, however, is quite well suited for testing other types of electric propulsion devices.

  15. Predicting breeding bird occurrence by stand- and microhabitat-scale features in even-aged stands in the Central Appalachians

    Science.gov (United States)

    McDermott, M.E.; Wood, P.B.; Miller, G.W.; Simpson, B.T.

    2011-01-01

    Spatial scale is an important consideration when managing forest wildlife habitat, and models can be used to improve our understanding of these habitats at relevant scales. Our objectives were to determine whether stand- or microhabitat-scale variables better predicted bird metrics (diversity, species presence, and abundance) and to examine breeding bird response to clearcut size and age in a highly forested landscape. In 2004-2007, vegetation data were collected from 62 even-aged stands that were 3.6-34.6. ha in size and harvested in 1963-1990 on the Monongahela National Forest, WV, USA. In 2005-2007, we also surveyed birds at vegetation plots. We used classification and regression trees to model breeding bird habitat use with a suite of stand and microhabitat variables. Among stand variables, elevation, stand age, and stand size were most commonly retained as important variables in guild and species models. Among microhabitat variables, medium-sized tree density and tree species diversity most commonly predicted bird presence or abundance. Early successional and generalist bird presence, abundance, and diversity were better predicted by microhabitat variables than stand variables. Thus, more intensive field sampling may be required to predict habitat use for these species, and management may be needed at a finer scale. Conversely, stand-level variables had greater utility in predicting late-successional species occurrence and abundance; thus management decisions and modeling at this scale may be suitable in areas with a uniform landscape, such as our study area. Our study suggests that late-successional breeding bird diversity can be maximized long-term by including harvests >10. ha in size into our study area and by increasing tree diversity. Some harvesting will need to be incorporated regularly, because after 15 years, the study stands did not provide habitat for most early successional breeding specialists. ?? 2010 Elsevier B.V.

  16. Inventory of Atlantic White Cedar Remnant Stands in North Carolina.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This inventory was commissioned by the U.S. Air Force to identify the location and condition of extant remnant Atlantic white cedar groves and stands in North...

  17. Basic Stand Alone Skilled Nursing Facility Beneficiary PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Skilled Nursing Facility (SNF) Beneficiary Public Use Files (PUF) with information from Medicare SNF claims. The...

  18. Standing - Challenges to Government Surveillance - Clapper v. Amnesty International USA

    National Research Council Canada - National Science Library

    2013-01-01

      Last Term, in Clapper v. Amnesty International USA, the Supreme Court held that the plaintiffs -- various attorneys and human rights organizations -- lacked standing to challenge section 702 of the Foreign Intelligence...

  19. Environmental Assessment : Marais des Cygnes National Wildlife Refuge tree stands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment is to evaluate whether current regulations regarding tree stands on the Marais des Cygnes National Wildlife Refuge are sufficient or...

  20. Robot-supported assessment of balance in standing and walking

    NARCIS (Netherlands)

    Shirota, Camila; Van Asseldonk, Edwin; Matjačić, Zlatko; Vallery, Heike; Barralon, Pierre; Maggioni, Serena; Buurke, Jaap H.; Veneman, Jan F.

    2017-01-01

    Clinically useful and efficient assessment of balance during standing and walking is especially challenging in patients with neurological disorders. However, rehabilitation robots could facilitate assessment procedures and improve their clinical value. We present a short overview of balance

  1. Engine Test Stand Design Constraints Expert System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Propulsion test stands are designed for thermal and pressure loads for certain classes of engines. These plume induced loads are: radiative heating, acoustics and...

  2. Optimal planning of stand-alone microgrids incorporating reliability

    National Research Council Canada - National Science Library

    WANG, Chengshan; JIAO, Bingqi; GUO, Li; YUAN, Kai; SUN, Bing

    2014-01-01

    This paper proposes a new method for the planning of stand-alone microgrids. By means of clustering techniques, possible operating scenarios are obtained considering the daily patterns of wind and load profiles...

  3. Infrared differential absorption lidar for stand-off detection of ...

    Indian Academy of Sciences (India)

    2014-02-14

    ) carbon dioxide laser-based differential absorption lidar (DIAL) system capable of stand-off detection of chemical clouds in aerosol and vapour form upto about 200 m range in the atmosphere has been developed and ...

  4. Isopropyl alcohol tank installed at A-3 Test Stand

    Science.gov (United States)

    2009-01-01

    An isopropyl alcohol (IPA) tank is lifted into place at the A-3 Test Stand being built at NASA's John C. Stennis Space Center. Fourteen IPA, water and liquid oxygen (LOX) tanks are being installed to support the chemical steam generators to be used on the A-3 Test Stand. The IPA and LOX tanks will provide fuel for the generators. The water will allow the generators to produce steam that will be used to reduce pressure inside the stand's test cell diffuser, enabling operators to simulate altitudes up to 100,000 feet. In that way, operators can perform the tests needed on rocket engines being built to carry humans back to the moon and possibly beyond. The A-3 Test Stand is set for completion and activation in 2011.

  5. International Society of Sports Nutrition position stand: energy drinks

    National Research Council Canada - National Science Library

    Campbell, Bill; Wilborn, Colin; La Bounty, Paul; Taylor, Lem; Nelson, Mike T; Greenwood, Mike; Ziegenfuss, Tim N; Lopez, Hector L; Hoffman, Jay R; Stout, Jeffrey R; Schmitz, Stephen; Collins, Rick; Kalman, Doug S; Antonio, Jose; Kreider, Richard B

    2013-01-01

    Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature on the safety and efficacy of the use of energy drinks (ED) or energy shots (ES...

  6. Structural attributes of stand overstory and light under the canopy

    Directory of Open Access Journals (Sweden)

    Alice Angelini

    2015-02-01

    Full Text Available  This paper reviews the literature relating to the relationship between light availability in the understory and the main qualitative and quantitative attributes of stand overstory usually considered in forest management and planning (species composition, density, tree sizes, etc. as well as their changes as consequences of harvesting. The paper is divided in two sections: the first one reviews studies which investigated the influence of species composition on understory light conditions; the second part examines research on the relationships among stand parameters determined from dendrometric field data and the radiation on understory layer. The objective was to highlight which are the most significant stand traits and management features to build more practical models for predicting light regimes in any forest stand and, in more general terms, to support forest managers in planning and designing silvicultural treatments that retain structure in different way in order to meet different objectives.

  7. A comparison of soil moisture relations between standing and ...

    African Journals Online (AJOL)

    A comparison of soil moisture relations between standing and clearfelled plots with burnt and unburnt harvest residue treatments of a clonal eucalypt plantation on the Zululand Coastal Plain, South Africa.

  8. One-leg standing balance and sports activity.

    Science.gov (United States)

    Hahn, T; Foldspang, A; Vestergaard, E; Ingemann-Hansen, T

    1999-02-01

    The objective of the present cross-sectional study was to estimate one-leg standing balance in athletes and to investigate the relationship with type and amount of sports activity. The study comprised 339 active, competitive, non-pregnant athletes, aged 14-24 years from two sports clubs in the county of Aarhus, Denmark. The athletes answered a questionnaire about occupation and sports activity. One-leg standing balance was measured as the maximum time of one-legged balancing. The mean of the maximum time of one-legged balancing was 29 s (interquartile range 11.25-33.5 s). One-leg standing balance was positively associated with years of participation in basketball and was not associated with sex and age. We conclude that participation in basketball may induce significantly adaptive effects on standing balance.

  9. Lift performance and lumbar loading in standing and seated lifts.

    Science.gov (United States)

    Middleton, Kane J; Carstairs, Greg L; Ham, Daniel J

    2016-09-01

    This study investigated the effect of posture on lifting performance. Twenty-three male soldiers lifted a loaded box onto a platform in standing and seated postures to determine their maximum lift capacity and maximum acceptable lift. Lift performance, trunk kinematics, lumbar loads, anthropometric and strength data were recorded. There was a significant main effect for lift effort but not for posture or the interaction. Effect sizes showed that lumbar compression forces did not differ between postures at lift initiation (Standing 5566.2 ± 627.8 N; Seated 5584.0 ± 16.0) but were higher in the standing posture (4045.7 ± 408.3 N) when compared with the seated posture (3655.8 ± 225.7 N) at lift completion. Anterior shear forces were higher in the standing posture at both lift initiation (Standing 519.4 ± 104.4 N; Seated 224.2 ± 9.4 N) and completion (Standing 183.3 ± 62.5 N; Seated 71.0 ± 24.2 N) and may have been a result of increased trunk flexion and a larger horizontal distance of the mass from the L5-S1 joint. Practitioner Summary: Differences between lift performance and lumbar forces in standing and seated lifts are unclear. Using a with-in subjects repeated measures design, we found no difference in lifted mass or lumbar compression force at lift initiation between standing and seated lifts.

  10. Destroyed virgin longleaf pine stand lives-on digitally

    Science.gov (United States)

    John C. Gilbert; S. Kush; Rebecca J. Barlow

    2015-01-01

    The Flomaton Natural Area (FNA) once stood as one of the few remnant fragments of virgin, old-growth longleaf pine stands (Pinus palustris Mill.) in the Southeast. This 80-acre stand contained trees over 200 years old. A restoration effort began in 1994 to remove off-site trees and to reintroduce fire to the site after over 40 years of fire suppression. A geographic...

  11. Effects of sound on postural stability during quiet standing

    OpenAIRE

    Park Sung; Lee Kichol; Lockhart Thurmon; Kim Sukwon

    2011-01-01

    Abstract Loss of postural stability can increase the likelihood of slips and falls in workplaces. The present study intended to extend understanding of the effects of frequency and pressure level of sound on postural stability during standing. Eleven male subjects participated. Standing on a force platform, the subjects' center of pressures were measured under different combinations of pressure level and frequency of the sound. Variables such as the position variability of COP and the length ...

  12. Vibration transmission characteristics of the legs of freely standing honeybees

    DEFF Research Database (Denmark)

    Rohrseitz, Kristin; Kilpinen, Ole

    1997-01-01

    The leg vibrations of honeybees standing on a vibrating substrate were measured with laser Doppler vibrometry, both in freely standing bees and in bees attached to a holder. In both cases, no resonances were found. In the fixed bee preparation, the legs moved with approximately the same amplitude...... that the subgenual organ is sensitive mainly to vibrations in the direction of the long axis of the leg....

  13. Stationary Density Variation Produced by a Standing Plasma Wave

    DEFF Research Database (Denmark)

    Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

    1977-01-01

    Measurements are presented of a stationary density modulation produced by a standing electron plasma wave. The experimental results are well explained by taking into account the ponderomotive forces on the electrons exerted by the high frequency field.......Measurements are presented of a stationary density modulation produced by a standing electron plasma wave. The experimental results are well explained by taking into account the ponderomotive forces on the electrons exerted by the high frequency field....

  14. Assessment framework for standardisation activities ResiStand

    OpenAIRE

    Stolk, D.J.; Lee, M.D.E. van der; Petiet, P.J.; Liedtke, C; Lindner, R.; Zetten, J. van; Karppinen, A.; Anson, S.; Kroener, I.

    2017-01-01

    Standardisation is a powerful tool to achieve better interoperability. However, it needs to overcome a lack of interest and modest participation from stakeholders. Also, promising research results are not always used as the basis for new standards. The overall goal of ResiStand is to find new ways to improve the crisis management and disaster resilience capabilities of the European Union and individual Member States through standardisation. ResiStand contributes to an improved disaster resili...

  15. Mixing Effects in Norway Spruce—European Beech Stands Are Modulated by Site Quality, Stand Age and Moisture Availability

    Directory of Open Access Journals (Sweden)

    Léa Houpert

    2018-02-01

    Full Text Available Although mixing tree species is considered an efficient risk-reduction strategy in the face of climate change, the conditions where mixtures are more productive than monocultures are under ongoing debate. Generalizations have been difficult because of the variety of methods used and due to contradictory findings regarding the effects of the species investigated, mixing proportions, and many site and stand conditions. Using data from 960 plots of the Swiss National Forest Inventory data, we assessed whether Picea abies (L. Karst–Fagus sylvatica L. mixed stands are more productive than pure stands, and whether the mixing effect depends on site- or stand-characteristics. The species proportions were estimated using species proportion by area, which depends on the maximum stand basal area of an unmanaged stand (BAmax. Four different alternatives were used to estimate BAmax and to investigate the effect of these differing alternatives on the estimated mixture effect. On average, the mixture had a negative effect on the growth of Picea abies. However, this effect decreased as moisture availability increased. Fagus sylvatica grew better in mixtures and this effect increased with site quality. A significant interaction between species proportions and quadratic mean diameter, a proxy for stand age, was found for both species: the older the stand, the better the growth of Fagus sylvatica and the lower the growth of Picea abies. Overyielding was predicted for 80% of the investigated sites. The alternative to estimate BAmax weakly modulated the estimated mixture effect, but it did not affect the way mixing effects changed with site characteristics.

  16. 2015 Space Radiation Standing Review Panel

    Science.gov (United States)

    Steinberg, Susan

    2015-01-01

    The 2015 Space Radiation Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on December 8 - 9, 2015. The SRP met with representatives from the Space Radiation Element and members of the Human Research Program (HRP) to review the updated research plan for the Risk of Radiation Carcinogenesis Cancer Risk. The SRP also reviewed the newly revised Evidence Reports for the Risk of Acute Radiation Syndromes Due to Solar Particle Events (SPEs) (Acute Risk), the Risk of Acute (In-flight) and Late Central Nervous System Effects from Radiation Exposure (CNS Risk), and the Risk of Cardiovascular Disease and Other Degenerative Tissue Effects from Radiation (Degen Risk), as well as a status update on these Risks. The SRP would like to commend Dr. Simonsen, Dr. Huff, Dr. Nelson, and Dr. Patel for their detailed presentations. The Space Radiation Element did a great job presenting a very large volume of material. The SRP considers it to be a strong program that is well-organized, well-coordinated and generates valuable data. The SRP commended the tissue sharing protocols, working groups, systems biology analysis, and standardization of models. In several of the discussed areas the SRP suggested improvements of the research plans in the future. These include the following: It is important that the team has expanded efforts examining immunology and inflammation as important components of the space radiation biological response. This is an overarching and important focus that is likely to apply to all aspects of the program including acute, CVD, CNS, cancer and others. Given that the area of immunology/inflammation is highly complex (and especially so as it relates to radiation), it warrants the expansion of investigators expertise in immunology and inflammation to work with the individual research projects and also the NASA Specialized Center of Research (NSCORs). Historical data on radiation injury to be entered into the Watson

  17. Walking reduces sensorimotor network connectivity compared to standing

    Science.gov (United States)

    2014-01-01

    Background Considerable effort has been devoted to mapping the functional and effective connectivity of the human brain, but these efforts have largely been limited to tasks involving stationary subjects. Recent advances with high-density electroencephalography (EEG) and Independent Components Analysis (ICA) have enabled study of electrocortical activity during human locomotion. The goal of this work was to measure the effective connectivity of cortical activity during human standing and walking. Methods We recorded 248-channels of EEG as eight young healthy subjects stood and walked on a treadmill both while performing a visual oddball discrimination task and not performing the task. ICA parsed underlying electrocortical, electromyographic, and artifact sources from the EEG signals. Inverse source modeling methods and clustering algorithms localized posterior, anterior, prefrontal, left sensorimotor, and right sensorimotor clusters of electrocortical sources across subjects. We applied a directional measure of connectivity, conditional Granger causality, to determine the effective connectivity between electrocortical sources. Results Connections involving sensorimotor clusters were weaker for walking than standing regardless of whether the subject was performing the simultaneous cognitive task or not. This finding supports the idea that cortical involvement during standing is greater than during walking, possibly because spinal neural networks play a greater role in locomotor control than standing control. Conversely, effective connectivity involving non-sensorimotor areas was stronger for walking than standing when subjects were engaged in the simultaneous cognitive task. Conclusions Our results suggest that standing results in greater functional connectivity between sensorimotor cortical areas than walking does. Greater cognitive attention to standing posture than to walking control could be one interpretation of that finding. These techniques could be applied

  18. Inflight exercise affects stand test responses after space flight

    Science.gov (United States)

    Lee, S. M.; Moore, A. D. Jr; Fritsch-Yelle, J. M.; Greenisen, M. C.; Schneider, S. M.

    1999-01-01

    PURPOSE: The purpose of this study was to determine whether exercise performed by Space Shuttle crew members during short-duration space flights (9-16 d) affects the heart rate (HR) and blood pressure (BP) responses to standing within 2-4 h of landing. METHODS: Thirty crew members performed self-selected inflight exercise and maintained exercise logs to monitor their exercise intensity and duration. Two subjects participated in this investigation during two different flights. A 10-min stand test, preceded by at least 6 min of quiet supine rest, was completed 10-15 d before launch (PRE) and within 4 h of landing (POST). Based upon their inflight exercise records, subjects were grouped as either high (HIex: > or = 3 times/week, HR > or = 70% HRmax, > or = 20 min/session, N = 11), medium (MEDex: > or = 3 times/week, HR or = 20 min/session, N = 10), or low (LOex: PRE differences between the groups in supine or standing HR and BP. Although POST supine HR was similar to PRE, all groups had an increased standing HR compared with PRE. The increase in HR upon standing was significantly greater after flight in the LOex group (36 +/- 5 bpm) compared with HIex or MEDex groups (25 +/- 1 bpm; 22 +/- 2 bpm). Similarly, the decrease in pulse pressure (PP) from supine to standing was unchanged after space flight in the MEDex and HIex groups but was significantly greater in the LOex group (PRE: -9 +/- 3; POST: -19 +/- 4 mm Hg). CONCLUSIONS: Thus, moderate to high levels of inflight exercise attenuated HR and PP responses to standing after space flight.

  19. Post-breeding bird responses to canopy tree retention, stand size, and edge in regenerating Appalachian hardwood stands

    Science.gov (United States)

    McDermott, M.E.; Wood, P.B.

    2011-01-01

    Avian use of even-aged timber harvests is likely affected by stand attributes such as size, amount of edge, and retained basal area, all characteristics that can easily be manipulated in timber harvesting plans. However, few studies have examined their effects during the post-breeding period. We studied the impacts of clearcut, low-leave two-age, and high-leave two-age harvesting on post-breeding birds using transect sampling and mist-netting in north-central West Virginia. In our approach, we studied the effects of these harvest types as well as stand size and edge on species characteristic of both early-successional and mature forest habitats. In 2005-2006, 13 stands ranging from 4 to 10. years post-harvest and 4-21. ha in size were sampled from late June through mid-August. Capture rates and relative abundance were similar among treatments for generalist birds. Early-successional birds had the lowest capture rates and fewer species (~30% lower), and late-successional birds reached their highest abundance and species totals (double the other treatments) in high-leave two-age stands. Area sensitivity was evident for all breeding habitat groups. Both generalist and late-successional bird captures were negatively related to stand size, but these groups showed no clear edge effects. Mean relative abundance decreased to nearly zero for the latter group in the largest stands. In contrast, early-successional species tended to use stand interiors more often and responded positively to stand size. Capture rates for this group tripled as stand size increased from 4 to 21. ha. Few birds in the forest periphery responded to harvest edge types despite within-stand edge effects evident for several species. To create suitable habitat for early-successional birds, large, non-linear openings with a low retained basal area are ideal, while smaller harvests and increased residual tree retention would provide habitat for more late-successional birds post-breeding. Although our study

  20. Responses of the lichen Ramalina menziesii Tayl. to ozone fumigations

    Science.gov (United States)

    J. Riddell; T.H. Nash; P. Padgett

    2010-01-01

    Tropospheric ozone (O3) is a strong oxidant, and is known to have serious negative effects on forest health. Lichens have bccn used as biomonitors of the effects of air pollution on forest health for sulfur and nitrogen pollutants. However, effects of O3 on lichens are not well understood, as past fumigation studies and...

  1. A Measurement System of Electric Signals on Standing Trees

    Directory of Open Access Journals (Sweden)

    Hao TIAN

    2014-01-01

    Full Text Available The standing tree electric signal (STES, defined as the electric potential difference between standing trees and the surrounding soil, can be utilized to reflect the biological nature of the trees. This signal should be measured precisely because it can also be collected and used as the electric power energy. In this paper, the automatic measurement system of standing tree biological electric signal based on MSP430 MCU. First of all, the basic structure of the presented system is introduced and it includes three modules: amplification module of the standing tree electric signal, the acquisition and processing of the signal module and the serial communication module. Then, the performances of the built system are respectively validated by the Poplar, Planetree, and Platanus in Beijing Forestry University. The result indicated that the relative error of this system is less than 2 %. The presented system can be considered as the foundation of the subsequent study on the mechanism of the biological electric signal and the application of the biological electric energy on standing trees.

  2. Measurement of lying and standing blood pressure in hospital.

    Science.gov (United States)

    O'Riordan, Shelagh; Vasilakis, Naomi; Hussain, Labib; Schoo, Rowena; Whitney, Julie; Windsor, Julie; Horton, Khim; Martin, Finbarr

    2017-09-29

    Measuring lying and standing blood pressure (BP) is an important clinical observation in older hospital inpatients. This is because a drop in BP on standing, known as orthostatic hypotension (OH) is common in older people and in acute illness and, therefore, in hospital patients. OH increases the risk of a fall in hospital. Simple measures such as changes in medication or rehydration can reduce this drop in BP and reduce the risk of falls. In a recent snapshot audit in England and Wales of 179 acute hospitals and 4,846 patients aged 65 years and over admitted with an acute illness, only 16% had a lying and standing BP recorded within 48 hours. A review of the literature showed that existing advice on how to measure and interpret lying and standing BP was often not appropriate for use on the ward with frail and unwell inpatients. An online survey of 275 clinicians' usual practice highlighted variation and the need for clarity and pragmatism. In the light of the survey findings, a clinical guide has been developed on when to measure lying and standing BP, how to measure it and what is considered a significant result. ©2012 RCN Publishing Company Ltd. All rights reserved. Not to be copied, transmitted or recorded in any way, in whole or part, without prior permission of the publishers.

  3. Energy cost of the case Western reserve standing neuroprosthesis.

    Science.gov (United States)

    Forrest, George P; Smith, Thomas C; Triolo, Ronald J; Gagnon, Jason P; DiRisio, Darryl; Miller, Michael E; Murray, Lori; Davis, John A; Iqbal, Atif

    2007-08-01

    To determine the oxygen consumption of a person with C7 American Spinal Injury Association (ASIA) grade B tetraplegia using the Case Western Reserve/Veterans Administration (CWRU/VA) standing neuroprosthesis. Measure the oxygen consumption and carbon dioxide production of a person with C7 ASIA grade B tetraplegia at rest, standing in the parallel bars with the CWRU/VA system on, ambulating in the parallel bars, and transferring from a wheelchair to a mat with the system on. University medical center. A 26-year-old man with C7 ASIA grade B tetraplegia. The subject was a recipient of the CWRU/VA standing neuroprosthesis. Not applicable. Measurement of oxygen consumption and carbon dioxide production using a metabolic cart. Oxygen consumption of the subject was 1.22mL.kg(-1).min(-1) at rest. It was 4.7mL.kg(-1).min(-1) while standing in the parallel bars, 7.2mL.kg(-1).min(-1) while ambulating in the parallel bars, and 7.9mL.kg(-1).min(-1) when transferring from a wheelchair to a mat. Oxygen consumption of the subject when using the system is about 2 metabolic equivalent units, which is compatible with sustained use of the system for standing.

  4. Laboratory stands for research of security systems’ components

    Directory of Open Access Journals (Sweden)

    Joanna Ćwirko

    2015-12-01

    Full Text Available The article presents two laboratory stands for research of basic security systems’ components. PIR detectors are the most widely used components in alarm systems. PIR detector element is a pyroelectric detector — its parameters determine the sensitivity of the detector and its resistance to “false alarms”. The completed laboratory stand allows for a comprehensive study of pyroelectric detectors, including work in a wide temperature range — to protect peripheral objects. The stand consists of radiation source (calibrator, the mechanical modulator, Peltier (change of temperature detector and measuring instruments.The main purpose of access control system (ACC is the selection of access to a wide variety of objects and technical systems. Realized laboratory set consists of 4 individual stands KD. Single stand KD is controlled by the transition controller module and base element is the door module. Depending on the desired configuration of the door module is equipped with: a smart card reader with keypad, Dallas chip reader, opening button or keypad. The access is defined for users — we have a weekly schedule, day and so-called time frames.[b]Keywords[/b]: pyroelectric detector, environment studies, access control system

  5. Mechanized stand treatment in young stands - stress and strain on the machine operator

    Energy Technology Data Exchange (ETDEWEB)

    Gellerstedt, S. [Swedish Univ. of Agricultural Sciences, Garpenberg (Sweden). Dept. of Operational Efficiency

    1996-12-31

    An analysis of mechanized spacing and cleaning was carried out in order to understand why, how and when the operator gather information; to understand which mental processes the operator use, as well as how he execute the physical work and how he gets feed-back from the work. Description of the work and its influence on the operator`s reactions is based on interviews, time-studies, the analysis of video films as well as on observations. The operator`s heart rate variability was measured as an indicator of mental effort. The electrical activity in the trapezius muscle was measured and analyzed with consideration to breaks. There are many work elements which call for the operator`s attention. The managing of the machine occupy the attention while biological assessments are needed. The limited sight hampers the operator possibility to quickly grasp the necessary information about the young tree stand and the terrain. The intense operation of the crane caused few pauses (emg-gaps) in the trapezius muscle. The low heart rate variability indicated a high mental workload, probably explained by high concentration. Proposals for technical development are given. A better sight, more `sensibility` of the cleaning head and aids for orientation would give the operator more efficient information. A partly robotized crane, a turnable cabin which adjusts its horizontal position automatically and better absorbs the vibrations, would give a more relaxed working environment. 14 refs , 3 figs, 4 tabs

  6. Performing Arabness in Arab American Stand-up Comedy

    Directory of Open Access Journals (Sweden)

    Fouad Selim Yasser

    2014-12-01

    Full Text Available This article deals with the dramatic art of stand-up comedy. It locates Arab American stand-up comedy within a broader American humorous tradition and investigates the way Arab American performers use this art to negotiate and (reconstruct their identity. The main question in this article is the way Arab American stand-up comedians define their relationship to the Arab and the western worlds in the process of establishing their Arab American identity. Three humor theories - the relief theory, the incongruity theory, and the superiority theory - are deployed in the study to examine the representation of Arabness in selected Arab American performances. The study argues that Arab American comics minstrelize their own diasporic origin through reinscribing a range of orientalizing practices in order to claim their Americanness.

  7. Influence of noise on decay predictions in standing trees

    Science.gov (United States)

    Visalga, G.; Rupšys, P.; Petrauskas, E.

    2017-10-01

    In the present study, the stochastic process, termed the Vasicek, have been implemented to analyze propagation velocity data of stress wave that diffuses through the wood of decayed and sound stems in standing trees. Stochastic processes offer the possibility of capturing important distributional differences between stress wave velocity datasets of decayed and sound trees and make the detecting rule flexible to internal decay in standing trees. It is shown that the Vasicek type stochastic process is a possible candidate for statistical classification of waveforms. Rigorous quantile regression analysis is based on the conditional probability density functions whose are fitted for stress wave velocity datasets of sound and decayed trees. New developed detector rules derived from stochastic differential equations may be used as an initial tool for detecting internal decay in standing trees.

  8. A Standing-Wave Experiment with a Guitar

    Science.gov (United States)

    Inman, Fred W.

    2006-10-01

    When teaching standing waves, one often uses as examples musical instruments with strings, e.g., pianos, violins, and guitars. In today's popular music culture, young people may be more familiar with guitars than any other string instrument. I was helping my 15-year-old granddaughter make some repairs and adjustments to her electric guitar, and the subject of the spacing between the frets on the fingerboard was raised. I told her that the physics of standing waves and the equal tempered musical scale dictate the location of the frets. The purpose of this paper is to suggest that students might be introduced to the physics of standing waves using a guitar and to the formula for the fret locations. By measuring the positions of the frets, this formula can be tested.

  9. Normal distribution of standing balance for healthy Danish children

    DEFF Research Database (Denmark)

    Pedersen, Line Kjeldgaard; Ghasemi, Habib; Rahbek, Ole

    2013-01-01

    in children with orthopedic disabilities undergoing surgical procedures. Recent technology provides extremely usable sway analysis of balance parameters but a normal material for the standing balance of healthy children is lacking. Purpose/Aim of Study First, to assess standing balance in healthy Danish...... children using pedobarographic sway analysis. Second, to establish a reference for comparison of balance in children with orthopedic disorders. Materials and Methods 66 children aged 7-14 years from the 1 th , 3 th, 5th and 7th grade were included at a Danish public school after informed consent...... was obtained. The Tekscan F-scan Research was used and the pedobarographic measurements were analyzed with original Sway Analysis Module software. We did triple measurements on both standing pedobarograms with eyes open and eyes closed and averaged the results for each of the 5 parameters of balance...

  10. Stand quality management of a water oak plantation in Louisiana: preliminary results following thinning

    Science.gov (United States)

    James S. Meadows; Daniel A., Jr. Skojac

    2010-01-01

    Stand quality management is a new guiding principle in which thinning prescriptions are based on tree quality rather than on residual stand density. We recently initiated a series of hardwood thinning studies to determine the effects of four stand quality management thinning prescriptions on both stand-level and individual-tree-level growth, quality, and value: (1) no...

  11. Spatial variation of fuel loading within varying aged stands of chaparral

    Science.gov (United States)

    Kellie A. Uyeda; Douglas A. Stow; John F. O' Leary; Ian T. Schmidt; Philip J. Riggan

    2016-01-01

    Questions: How do stand-level biomass and percentage of deadmaterial in chaparral vary as a function of stand age? How do the landscape properties of aggregation index and patch size vary in each of the dominant species groups as a function of stand age? Location: Stands of 7-, 28-and 68-yr-old...

  12. Spatial Interactions in Multiple-Use Forestry and Substitution and Wealth Effects for the Single Stand

    Science.gov (United States)

    Stephen K. Swallow; David N. Wear

    1993-01-01

    Forestry models often ignore spatial relationships between forest stands. This paper isolates the effects of stand interactions in muitiple-use forestry through a straightforward extension of the single-stand model. Effects of stand interactions decompose into wealth and substitution effects and may cause time-varying patterns of resource use for a forest...

  13. Variable-density thinning in coast redwood: a comparison of marking strategies to attain stand variability

    Science.gov (United States)

    Kevin L. O' Hara; Lathrop P. Leonard; Christopher R. Keyes

    2012-01-01

    Variable-density thinning (VDT) is an emerging thinning method that attempts to enhance stand structural heterogeneity by deliberately thinning at different intensities throughout a stand. VDT may create stands with dense areas, open areas, and other areas that may be intermediate in density. Subsequent stand development forms a more varied structure than is...

  14. Regenerating mixed oak stands in Pennsylvania: a quarter-century retrospective

    Science.gov (United States)

    P. J. Gould; K. C. Steiner; J. C. Finley; M. E. McDill

    2003-01-01

    The outcomes of regeneration treatments in 90 oak-dominated stands in Pennsylvania are examined 20 to 33 years after treatment. Approximately one-quarter of the stands failed to reach 50 percent stocking after at least 20 years, but most stands regenerated successfully. Red maple is the most frequently observed species in the regenerated stands, followed by oak species...

  15. Standing Up for Learning: A Pilot Investigation on the Neurocognitive Benefits of Stand-Biased School Desks

    Directory of Open Access Journals (Sweden)

    Ranjana K. Mehta

    2015-12-01

    Full Text Available Standing desks have proven to be effective and viable solutions to combat sedentary behavior among children during the school day in studies around the world. However, little is known regarding the potential of such interventions on cognitive outcomes in children over time. The purpose of this pilot study was to determine the neurocognitive benefits, i.e., improvements in executive functioning and working memory, of stand-biased desks and explore any associated changes in frontal brain function. 34 freshman high school students were recruited for neurocognitive testing at two time points during the school year: (1 in the fall semester and (2 in the spring semester (after 27.57 (1.63 weeks of continued exposure. Executive function and working memory was evaluated using a computerized neurocognitive test battery, and brain activation patterns of the prefrontal cortex were obtained using functional near infrared spectroscopy. Continued utilization of the stand-biased desks was associated with significant improvements in executive function and working memory capabilities. Changes in corresponding brain activation patterns were also observed. These findings provide the first preliminary evidence on the neurocognitive benefits of standing desks, which to date have focused largely on energy expenditure. Findings obtained here can drive future research with larger samples and multiple schools, with comparison groups that may in turn implicate the importance of stand-biased desks, as simple environmental changes in classrooms, on enhancing children’s cognitive functioning that drive their cognitive development and impact educational outcomes.

  16. Simulating stand climate, phenology, and photosynthesis of a forest stand with a process-based growth model.

    Science.gov (United States)

    Rötzer, Thomas; Leuchner, Michael; Nunn, Angela J

    2010-07-01

    In the face of climate change and accompanying risks, forest management in Europe is becoming increasingly important. Model simulations can help to understand the reactions and feedbacks of a changing environment on tree growth. In order to simulate forest growth based on future climate change scenarios, we tested the basic processes underlying the growth model BALANCE, simulating stand climate (air temperature, photosynthetically active radiation (PAR) and precipitation), tree phenology, and photosynthesis. A mixed stand of 53- to 60-year-old Norway spruce (Picea abies) and European beech (Fagus sylvatica) in Southern Germany was used as a reference. The results show that BALANCE is able to realistically simulate air temperature gradients in a forest stand using air temperature measurements above the canopy and PAR regimes at different heights for single trees inside the canopy. Interception as a central variable for water balance of a forest stand was also estimated. Tree phenology, i.e. bud burst and leaf coloring, could be reproduced convincingly. Simulated photosynthesis rates were in accordance with measured values for beech both in the sun and the shade crown. For spruce, however, some discrepancies in the rates were obvious, probably due to changed environmental conditions after bud break. Overall, BALANCE has shown to respond to scenario simulations of a changing environment (e.g., climate change, change of forest stand structure).

  17. Gender-based differences in the cardiovascular response to standing

    Science.gov (United States)

    Gotshall, Robert W.; Tsai, Pai-Feng; Frey, Mary A. B.

    1991-01-01

    The cardiovascular responses of men and women to the stand test were compared by measuring respective values for heart rate, blood pressure, stroke volume, cardiac output, and total peripheral resistance during a 5-min supine and a 5-min standing test in ten subjects of each gender. It was found that, while the male and female subjects had similar heart rate values, all other responses exhibited greater changes in men than in women. While differences in the height of the subjects did not account for differences in cardiovascular responses, no mechanism responsible for these differences could be identified.

  18. Customizable nanotweezers for manipulation of free-standing nanostructures

    DEFF Research Database (Denmark)

    Bøggild, Peter; Hansen, Torben Mikael; Mølhave, Kristian

    2001-01-01

    We present a novel nanotweezer device for manipulation and measurement of free-standing nanostructures, where the shape of the tweezer tips can be customized for the application. Electrostatic actuators with submicron interelectrode spacings are fabricated on a batch level using silicon microfabr......We present a novel nanotweezer device for manipulation and measurement of free-standing nanostructures, where the shape of the tweezer tips can be customized for the application. Electrostatic actuators with submicron interelectrode spacings are fabricated on a batch level using silicon...

  19. The stand-alone test and decreasing serial cost sharing

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Thorlund-Petersen, Lars

    2000-01-01

    The rule of decreasing serial cost sharing defined in de Frutos [1] over the class of concave cost functions may violate the important stand-alone test. Sufficient conditions for the test to be satisfied are given, in terms of individual rationality as well as coalitional stability. These conditi......The rule of decreasing serial cost sharing defined in de Frutos [1] over the class of concave cost functions may violate the important stand-alone test. Sufficient conditions for the test to be satisfied are given, in terms of individual rationality as well as coalitional stability....... These conditions restrict the shape of the cost function and the distribution of demands...

  20. A FEW CONSIDERATIONS ABOUT TRADE FAIR STANDS DESIGN

    Directory of Open Access Journals (Sweden)

    NEIDONI Nadina

    2017-05-01

    Full Text Available The paper presents some aspects related to the design of a trade fair stand, advertising a company specialized in the fabrication of corrugated fibre board packaging. The first section reviews shortly the main features of the industrial design. The second section deals with the structural conception of successful trade shows. Further, the importance of the package in the marketing matters is addressed. In this context corrugated fibreboard, as secondary or tertiary material is essential. In the final section, a comparison between two trade fair stands, representing a corrugated fibreboard company are presented.

  1. Dynamics models and modeling of tree stand development

    Directory of Open Access Journals (Sweden)

    M. V. Rogozin

    2015-04-01

    Full Text Available Brief analysis of scientific works in Russia and in the CIS over the past 100 years. Logical and mathematical models consider the conceptual and show some of the results of their verification. It was found that the models include different laws and the parameters, the sum of which allows you to divide them into four categories: models of static states, development models, models of care for the natural forest and models of cultivation. Each category has fulfilled and fulfills its tasks in economic management. Thus, the model states in statics (table traverse growth played a prominent role in figuring out what may be the most productive (full stands in different regions of the country. However, they do not answer the question of what the initial states lead to the production of complete stands. In a study of the growth of stands used system analysis, and it is observed dominance of works studying static state, snatched from the biological time. Therefore, the real drama of the growth of stands remained almost unexplored. It is no accident there were «chrono-forestry» «plantation forestry» and even «non-traditional forestry», where there is a strong case of a number of new concepts of development stands. That is quite in keeping with Kuhn (Kuhn, 2009 in the forestry crisis began – there were alternative theories and coexist conflicting scientific schools. To develop models of stand development, it is proposed to use a well-known method of repeated observations within 10–20 years, in conjunction with the explanation of the history of the initial density. It mounted on the basis of studying the dynamics of its indicators: the trunk, crown overlap coefficient, the sum of volumes of all crowns and the relative length of the crown. According to these indicators, the researcher selects natural series of development stands with the same initial density. As a theoretical basis for the models it is possible to postulate the general properties of

  2. NEW TECHNOLOGIES IN MEASUREMENT OF STANDING LONG JUMP

    Directory of Open Access Journals (Sweden)

    Ratko Stanković

    2008-08-01

    Full Text Available On the sample of 21 students of Faculty of sports and physical education, age 21±6 months, measurement of standing long jump length by using test for explosive puissance estimation of lower extremities was effected. Test was recorded by digital video camera, and all conditions for application of video analyses i.e. kinematics methods were present. After digitalization, record was mistreated and prepared for further manipulating by using appropriate software for video analyses. Four different persons measured jump length (4 items. Metric characteristics of standing long jump showed high signifi cation level.

  3. Standing Shocks in the Inner Slow Solar Wind

    Science.gov (United States)

    Li, Bo; Chen, Yan-Jun; Li, Xing

    2011-05-01

    We examine whether the now tube along the edge of a coronal streamer supports standing shocks in the inner slow wind by solving an isothermal wind model in terms of the Lambert W function. It is shown that solutions with standing shocks do exist and they exist in a broad area in the parameter space characterizing the wind temperature and now tube. In particular, streamers with cusps located at a heliocentric distance ≳ 3.2Rodot can readily support discontinuous slow winds with temperatures barely higher than 1 MK.

  4. Electron-phonon coupling in quasi free-standing graphene

    DEFF Research Database (Denmark)

    Christian Johannsen, Jens; Ulstrup, Søren; Bianchi, Marco

    2013-01-01

    Quasi free-standing monolayer graphene can be produced by intercalating species like oxygen or hydrogen between epitaxial graphene and the substrate crystal. If the graphene is indeed decoupled from the substrate, one would expect the observation of a similar electronic dispersion and many......-body effects, irrespective of the substrate and the material used to achieve the decoupling. Here we investigate the electron-phonon coupling in two different types of quasi free-standing monolayer graphene: decoupled from SiC via hydrogen intercalation and decoupled from Ir via oxygen intercalation. Both...

  5. Racial Issues in American Stand-up Comedy

    OpenAIRE

    Alina BOGDAN

    2014-01-01

    Stand-up comedy emerged in the late 1970s when the first live shows of this type were introduced to the public. This type of humour, which relies on ingenuity, contains a variety of topics used by comedians, such as their everyday life, religion, politics or racism. These are just a few of the topics usually employed in order to create comedy. It is curious how a serious matter such as racism, for example, can be used to trigger laughter. Eddie Griffin, an African American stand-up comedia...

  6. Natural seed fall in white pine (Pinus strobes L.) stands of varying density

    Science.gov (United States)

    Raymond E. Graber

    1970-01-01

    Seed fall was observed in three stands of mature white pines at stand basal-area densities of 80, 120, and 187 square feet per acre. It was found that the intermediate-density stand produced nearly 50 percent more seed than the stands of other densities. During a good seed year this stand produced 59 pounds of dry sound seed per acre. Most of the seeds were dispersed...

  7. A New Standing Posture Detector to Enable People with Multiple Disabilities to Control Environmental Stimulation by Changing Their Standing Posture through a Commercial Wii Balance Board

    Science.gov (United States)

    Shih, Ching-Hsiang; Shih, Ching-Tien; Chiang, Ming-Shan

    2010-01-01

    This study assessed whether two persons with multiple disabilities would be able to control environmental stimulation using body swing (changing standing posture) and a Wii Balance Board with a newly developed standing posture detection program (i.e. a new software program turns a Wii Balance Board into a precise standing posture detector). The…

  8. Method’s and Test Stand for Electronic PID Controller

    Directory of Open Access Journals (Sweden)

    Cristian Paul Chioncel

    2009-01-01

    Full Text Available The paper presents method’s and a testing stand for electronic controller using for this a signal generator and a digital oscilloscope respectively the virtual instrumentation and the signal acquisitions from the controllers input and output through an data acquisition board and an PC on that Lab View program runs.

  9. A perspective on the control of FES-supported standing

    NARCIS (Netherlands)

    Veltink, Petrus H.; Donaldson, Nick

    1998-01-01

    This special section is about the control of electrical stimulators to restore standing functions to paraplegics. It addresses several important topics regarding the interactions of the intact central nervous systems (CNS) with the artificial control system. The topics are as follows: how

  10. Assessment of Stand Density and Growth Rate of Three Tree ...

    African Journals Online (AJOL)

    Plots of Gmelina arborea, Nauclea diderrichii and Tectona grandis at the arboretum of the Department of Forestry and Wildlife, University of Uyo, were assessed for stand density and diameter growth rates of the tree species. All the trees in the three plots were counted and their diameters at breast height (dbh) measured.

  11. Quantitative Analysis of Complex Tropical Forest Stands: A Review ...

    African Journals Online (AJOL)

    The importance of data analysis in quantitative assessment of natural resources remains significant in the sustainable management of complex tropical forest resources. Analyses of data from complex tropical forest stands have not been easy or clear due to improper data management. It is pivotal to practical researches ...

  12. Microbial deterioration of stored water for users supplied by stand ...

    African Journals Online (AJOL)

    Two forms of water service delivery in peri-urban settlements in the eThekwini municipal region are communal stand-pipes and household ground-tanks. Water from these sources requires storage prior to use. Previous studies have shown that water quality tends to deteriorate during storage. This study was conducted ...

  13. The Relationship Between Foot and Pelvic Alignment While Standing

    Directory of Open Access Journals (Sweden)

    Khamis Sam

    2015-06-01

    Full Text Available A normal motion and segmental interrelationship has been determined as a significant factor in normal function. Yet, the relationship between distal segments and pelvic alignment needs further investigation. The aim of this study was to investigate the interrelationship between distal and proximal lower extremity segments while standing and during induced feet hyperpronation. Changes in alignment of the pelvis and lower extremities were measured at a gait laboratory using the VICON 612 computerized motion analysis system. Thirty-five healthy volunteer subjects were recruited. Four randomized repeated-measure standing modes were used: standing directly on the floor and then on three wedges angled at 10°, 15° and 20° to induce bilateral hyperpronation for 20 seconds. A significant (p<0.05 bi-variate relationship was found between the anterior pelvic tilt and thigh internal rotation, in all four standing positions (.41≤r≤.46, in all p<0.014. A combined effect of rotational alignment between segments and the cumulative effect of foot hyperpronation on pelvic tilt revealed that only the shank significantly affected pelvic alignment, acting as a mediator between a foot and a thigh with the thigh having a crude significant effect on the pelvis. When internal rotation of the shank occurs, calcaneal eversion couples with thigh internal rotation and anterior pelvic tilt. It can be concluded that in response to induced hyperpronation, the shank is a pivotal segment in postural adjustment.

  14. Assessing the Economic and Environmental Prospects of Stand-By ...

    African Journals Online (AJOL)

    This paper presents an economic analysis of two stand-by power supply options for a typical Nigerian household namely diesel generator plant and solar powered systems. The analysis reveals that solar systems are the most economically viable. The environmental benefits associated with substituting diesel powered ...

  15. Statistical sampling and modelling for cork oak and eucalyptus stands

    NARCIS (Netherlands)

    Paulo, M.J.

    2002-01-01

    This thesis focuses on the use of modern statistical methods to solve problems on sampling, optimal cutting time and agricultural modelling in Portuguese cork oak and eucalyptus stands. The results are contained in five chapters that have been submitted for publication

  16. The importance of spatial accuracy in characterizing stand types ...

    African Journals Online (AJOL)

    The study compared the performance of classification accuracies of satellite images into the forest cover type map (FCTM). The result shows that crown closure was the most successfully classified stand parameters with a 0.92 kappa statistic value and 94.2% overall accuracy assessments in 30 m resolution Landsat 7 ...

  17. Design of a quadrotor flight test stand for system identification

    CSIR Research Space (South Africa)

    Beharie, MM

    2015-01-01

    Full Text Available This paper presents the design, development and construction of a flight test stand for a quadrotor UAV. As opposed to alternate forms of UAV, the power plant in the case of the quadrotor serves a dual purpose of control and propulsion. Since...

  18. Step Prediction During Perturbed Standing Using Center Of Pressure Measurements

    Directory of Open Access Journals (Sweden)

    Milos R. Popovic

    2007-04-01

    Full Text Available The development of a sensor that can measure balance during quiet standing and predict stepping response in the event of perturbation has many clinically relevant applica- tions, including closed-loop control of a neuroprothesis for standing. This study investigated the feasibility of an algorithm that can predict in real-time when an able-bodied individual who is quietly standing will have to make a step to compensate for an external perturbation. Anterior and posterior perturbations were performed on 16 able-bodied subjects using a pul- ley system with a dropped weight. A linear relationship was found between the peak center of pressure (COP velocity and the peak COP displacement caused by the perturbation. This result suggests that one can predict when a person will have to make a step based on COP velocity measurements alone. Another important feature of this finding is that the peak COP velocity occurs considerably before the peak COP displacement. As a result, one can predict if a subject will have to make a step in response to a perturbation sufficiently ahead of the time when the subject is actually forced to make the step. The proposed instability detection algorithm will be implemented in a sensor system using insole sheets in shoes with minitur- ized pressure sensors by which the COPv can be continuously measured. The sensor system will be integrated in a closed-loop feedback system with a neuroprosthesis for standing in the near future.

  19. Productivity of a John Deere Harvester Unit in Deciduous Stands

    Directory of Open Access Journals (Sweden)

    Jozef Slugeň

    2014-01-01

    Full Text Available The aim of the presented paper was to determine the productivity of a John Deere 1070D harvester in deciduous coppices of Quercus petraea and Fagus sylvatica, in thinnings over 50 years of age. The research area was located in Tribeč mountain ridge, western Slovakia. The terrain incline did not exceed 20%. The productivity of the harvester in oak stands was 9.97 m3.h−1 without downtimes (breaks, failures, etc.. Performance with breaks was 4.98 m3.PMH−1 (productive machine hour. The productivity of the harvester was influenced by a large portion of passes of the harvester, which constituted 23.47% of the time of the operating cycle. The large number of passes was caused by the fact that the operator did not respect the technologic process and a high portion of tree extraction (8.45%. Furthermore the productivity was decreased by frequent failures of the machine and downtimes, which could be prevented by proper and regular maintenance. The productivity in beech stands was 6.36 m3.h−1 without downtimes and 5.35 m3.PMH−1 with downtimes included. Lower productivity was caused by the numerous and thick branches and frequent presence of trees with multiple tree tops, ergo unsuitable structure of the stand. Absence of a worker with a chainsaw was considered to be a disadvantage, because this worker is often a necessity when harvesters operate in deciduous stands.

  20. Finite Element Analysis of a Free-Standing Staircase | Ajagbe ...

    African Journals Online (AJOL)

    The existing approximate analytical methods of analyzing free-standing stairs fail to predict the distribution of any stress resultant and the actual three dimensional behavior of the stair slab system. A more rationale but simple and accurate method of analysis based on finite element method is presented. Plate flexural ...

  1. A stricter condition for standing balance after unexpected perturbations

    NARCIS (Netherlands)

    Hof, At L; Curtze, Carolin

    2016-01-01

    In order to account for the dynamic nature of balance, the concept of the 'extrapolated centre of mass' XcoM has been introduced (Hof et al., 2005). The law for standing balance was then formulated as: the XcoM should remain within the Base of Support (BoS). This law, however, does not take into

  2. Distribution and dynamics of hayscented fern following stand harvest

    Science.gov (United States)

    Songlin Fei; Peter J. Gould; Melanie J. Kaeser; Kim C. Steiner

    2008-01-01

    The distribution and dynamics of hayscented fern were examined as part of a large-scale study of oak regeneration in Pennsylvania. The study included 69 stands covering 3,333 acres in two physiographic provinces. Hayscented fern was more widely distributed and occurred at higher densities in the Allegheny Plateau physiographic provinces versus the Ridge and Valley...

  3. Litterfall and Nutrient Returns in Isolated Stands of Terminalia ...

    African Journals Online (AJOL)

    Litterfall and Nutrient Returns in Isolated Stands of Terminalia catappa Trees in the Rainforest Area of Southern Nigeria. ... has implications in returning nutrient elements to the soils of the rainforest ecosystem. Keywords: Litterfall, Nutrient returns, Seasonal variation, Southern Nigeria, Terminalia catappa, Tropical rainforest.

  4. 32 CFR 636.30 - Stopping, standing and parking.

    Science.gov (United States)

    2010-07-01

    ... Recreation Center, Holbrook Pond, Fort Stewart, or at the Private Vehicle Storage area at Hunter Army... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort... standing their vehicle, whether attended or unattended, upon the roadway when it is possible to stop, park...

  5. Implications of random variation in the Stand Prognosis Model

    Science.gov (United States)

    David A. Hamilton

    1991-01-01

    Although the Stand Prognosis Model has several stochastic components, features have been included in the model in an attempt to minimize run-to-run variation attributable to these stochastic components. This has led many users to assume that comparisons of management alternatives could be made based on a single run of the model for each alternative. Recent analyses...

  6. Verification of aerial photo stand volume tables for southeast Alaska.

    Science.gov (United States)

    Theodore S. Setzer; Bert R. Mead

    1988-01-01

    Aerial photo volume tables are used in the multilevel sampling system of Alaska Forest Inventory and Analysis. These volume tables are presented with a description of the data base and methods used to construct the tables. Volume estimates compiled from the aerial photo stand volume tables and associated ground-measured values are compared and evaluated.

  7. Censorship and the Internet. A Stand for School Librarians: Opinion.

    Science.gov (United States)

    Truett, Carol

    1997-01-01

    Discusses censorship, the Internet, and school librarians. Topics include the Communications Decency Act; the American Library Association's stand against censorship; the Constitution and the Bill of Rights; free flow of information versus responsible usage; the Internet's lack of government control; and school librarians as protectors of…

  8. The importance of spatial accuracy in characterizing stand types ...

    African Journals Online (AJOL)

    use

    2011-10-26

    Oct 26, 2011 ... inventory and land use planning. Key words: Image fusion, Landsat, spatial analysis, stand parameters. INTRODUCTION. In Turkey, forest ...... territories from high spatial resolution Quickbird satellite imagery. In: Safety, Security, and the Environment through Remote Sensing,. October 28 – November 1, ...

  9. Microbial deterioration of stored water for users supplied by stand ...

    African Journals Online (AJOL)

    difference in water quality between stand-pipe households that used open-top containers and those that used closed-top con- tainers. ... maintained better personal hygiene but lower container hygiene than those households consisting of children, whereas the ..... differences between source and point-of-use for total organ-.

  10. Development of spruce-fir stands following spruce beetle outbreaks

    Science.gov (United States)

    J. M. Schmid; T. E. Hinds

    1974-01-01

    Logged and unlogged stands of Engelmann spruce-subalpine fir were evaluated in spruce beetle outbreak areas infested about 15, 25, 50, and 100 years ago. Seedling regeneration was generally adequate except in heavily logged areas, although seedlings were often damaged, apparently by animals. Species composition was dramatically altered in favor of fir in the unlogged...

  11. College Athlete Stands Again…On His Own!

    Science.gov (United States)

    ... control of their paralyzed limbs. To see if spinal cord stimulation could be successful in people, Edgerton and his ... remain standing for a few minutes while receiving stimulation. With the support ... and the part of the spinal cord below the point of his injury may have ...

  12. Photosynthetic Characteristics of Five Hardwood Species in a Mixed Stand

    Science.gov (United States)

    Shi-Jean S. Sung; Paul P. Kormanik; Stanley J. Zarnoch

    1999-01-01

    In 1998, photosythesis (Pn) was measured in cherrybark oak, green ash, swamp chestnut oak, sweetgum, and water hickory in a mixed stand established in February 1994. Based on the apparent quantum yield obtained from light response curves, cherrybark oak had the lowest Pn in August whereas sweetgum, green ash, and water hickory were equally active in Pn. Daily August...

  13. Generalized height-diameter models for Populus tremula L. stands ...

    African Journals Online (AJOL)

    Using permanent sample plot data, selected tree height and diameter functions were evaluated for their predictive abilities for Populus tremula stands in Turkey. Two sets of models were evaluated. The first set included five models for estimating height as a function of individual tree diameter; the second set also included six ...

  14. What triggers the continuous muscle activity during upright standing?

    Science.gov (United States)

    Masani, Kei; Sayenko, Dimitry G; Vette, Albert H

    2013-01-01

    The ankle extensors play a dominant role in controlling the equilibrium during bipedal quiet standing. Their primary role is to resist the gravity toppling torque that pulls the body forward. The purpose of this study was to investigate whether the continuous muscle activity of the anti-gravity muscles during standing is triggered by the joint torque requirement for opposing the gravity toppling torque, rather than by the vertical load on the lower limbs. Healthy adults subjects stood on a force plate. The ankle torque, ankle angle, and electromyograms from the right lower leg muscles were measured. A ground-fixed support device was used to support the subject at his/her knees, without changing the posture from the free standing one. During the supported condition, which eliminates the ankle torque requirement while maintaining both the vertical load on the lower limbs and the natural upright standing posture, the plantarflexor activity was attenuated to the resting level. Also, this attenuated plantarflexor activity was found only in one side when the ipsilateral leg was supported. Our results suggest that the vertical load on the lower limb is not determinant for inducing the continuous muscle activity in the anti-gravity muscles, but that it depends on the required joint torque to oppose the gravity toppling torque. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Characteristics, histories, and future succession of northern Pinus pugens stands

    Science.gov (United States)

    Patrick Brose

    2017-01-01

    Pinus pungens (Table Mountain pine) stands are rare conifer-dominated communities that occur on xeric ridges and upper slopes throughout the central and southern Appalachian Mountains. At the northern end of this range, this uncommon forest community is essentially unstudied. Therefore, in 2006 I initiated a dendroecology study of three ...

  16. Economic optimization of the rotation age of stands

    Directory of Open Access Journals (Sweden)

    Płotkowski Lech

    2016-12-01

    Full Text Available The central task of this research was to choose the age at which stands of growing timber should be harvested. The choice governs how long each stand must continue to earn interest, and also governs the size of the total inventory that must be maintained to sustain the annual harvest. It is a problem that calls for analysis of biological as well as economic relationships over time, and has intrigued economists for more than two centuries. The paper presents the theoretical background and results of economic optimization of the rotation age of a single stand. It analyses the timber production function depending on rotation age, growth, cost and other characteristics of forest, as well as the costs of land. The prerequisite for achieving the economic optimum of the rotation age of a stand is to balance the current increase in the total timber production value (growth and yield and the value of opportunity costs from delaying cutting till the next year. This paper demonstrates how this economically optimum rotation age can be calculated, and how it varies according to the biological growth and economic parameters of the forest.

  17. MICRONUTRIENTS AND BIOMASS IN Eucalyptus dunnii Maiden STAND

    Directory of Open Access Journals (Sweden)

    Grasiele Dick

    Full Text Available ABSTRACT The expansion of silviculture in Brazil, and the consequent intensive practices for soil preparation with high demand for fertilizers require sustainable nutrient management of forest sites. The objective of this study was to quantify the biomass and the micronutrient stocks of a 60-month-old Eucalyptus dunnii stand established in Alegrete, Rio Grande do Sul. The stand was established in a Rhodic Paleudult soil with low fertility and texture varying between sandy loam and sandy-clay loam. For the sampling of stand biomass, twelve trees were harvested, sectioned at ground level, and subsequently fractionated into the components roots, leaves, branches, stembark and stemwood to determine the dry mass and micronutrient content. The total biomass of the stand was 67.49 Mg ha-1, with mass allocation in descending order from: stem wood > root > bark > branches > leaves. Total micronutrient stocks for boron (B, copper (Cu, iron (Fe, manganese (Mn and zinc (Zn were 562.57, 401.46, 9913.28, 31877.82, and 766.96 g ha-1, respectively. In addition, we found greater accumulation of Zn in the wood, high Mn accumulation especially in the bark, and high Fe content in the roots. Therefore, based on these micronutrient levels and their allocation between biomass fractions, we emphasize that the practice of retaining forest residues on-site after harvest is essential for forest nutrition through nutrient cycling and for soil conservation and fertility.

  18. Assessment framework for standardisation activities ResiStand

    NARCIS (Netherlands)

    Stolk, D.J.; Lee, M.D.E. van der; Petiet, P.J.; Liedtke, C.; Lindner, R.; Zetten, J. van; Karppinen, A.; Anson, S.; Kroener, I.

    2017-01-01

    Standardisation is a powerful tool to achieve better interoperability. However, it needs to overcome a lack of interest and modest participation from stakeholders. Also, promising research results are not always used as the basis for new standards. The overall goal of ResiStand is to find new ways

  19. Handgrip Strength in Individuals with Long- Standing Type 2 ...

    African Journals Online (AJOL)

    Adequate muscle strength is required for optimum productivity and low muscle strength is a predictor of physical limitations. Individuals with long-standing type 2 diabetes mellitus have been found to have an increased risk of developing functional disabilities. Handgrip strength is a reliable measurement of the disability ...

  20. ASSESSMENT OF STAND DENSITY AND GROWTH RATE OF ...

    African Journals Online (AJOL)

    ABIA

    Plots of Gmelina arborea, Nauclea diderrichii and Tectona grandis at the arboretum of the. Department of Forestry and Wildlife, University of Uyo, were assessed for stand density and diameter growth rates of the tree species. All the trees in the three plots were counted and their diameters at breast height (dbh) measured.

  1. Relative size and stand age determine Pinus banksiana mortality

    Science.gov (United States)

    Han Y. H. Chen; Songling Fu; Robert A. Monserud; Ian C. Gillies

    2008-01-01

    Tree mortality is a poorly understood process in the boreal forest. Whereas large disturbances reset succession by killing all or most trees, background tree mortality was hypothesized to be affected by competition, ageing, and stand composition. We tested these hypotheses on jack pine (Pinus banksiana Lamb.) mortality using data from long-term...

  2. Economic evaluation of intermediate operations in oak stands

    Science.gov (United States)

    Henry H. Webster; John C., Jr. Meadows

    1971-01-01

    Economic evaluation of forest-management opportunities is a vital ingredient of effective forestry programs. Choices among management opportunities are necessary because opportunities inevitably exceed funds available, and they are important because opportunities commonly range from highly productive to decidedly unproductive. Economic evaluation in oak stands shows a...

  3. The standing of the curriculum for consumer studies as school ...

    African Journals Online (AJOL)

    Consumer Studies has the potential to have a positive impact on learners and communities in South Africa. It has been taught in schools for a number of years but the standing of Consumer Studies curriculum as a subject in the National Senior Certificate (an NQF Level 4 qualification) has not yet been established.

  4. The standing of the curriculum for consumer studies as school

    African Journals Online (AJOL)

    user

    ISSN 0378-5254 Journal of Family Ecology and Consumer Sciences, Vol 41, 2013. The standing of the curriculum for consumer studies as school subject in the South African context. 86. (Act 27 of 1996). Umalusi‟s research investigated the curricula for both the South. African Department of Basic Education‟s (DBE).

  5. Orbital stability of standing waves for some nonlinear Schroedinger equations

    Energy Technology Data Exchange (ETDEWEB)

    Cazenave, T.; Lions, P.L.

    1982-08-01

    We present a general method which enables as to prove the orbital stability of some standing waves in nonlinear Schroedinger equations. For example, we treat the cases of nonlinear Schroedinger equations arising in laser beams, of time-dependent Hartree equations.

  6. Deriving fair incentives for management of hardwood timber stands

    Science.gov (United States)

    David A. Gansner; W. Herrick Owen; David N. Larsen; David N. Larsen

    1973-01-01

    The authors present a practical method for deriving timber-management incentive payments and demonstrate its application in forest stands of upland hardwoods. The suggested incentive payment is based on the differences between discounted costs and returns of deliberate forest management and the "harvest and let grow" option.

  7. Forest stand dynamics of shortleaf pine in the Ozarks

    Science.gov (United States)

    David R. Larsen

    2007-01-01

    Much has been written on the management of shortleaf pine in the Ozarks (Brinkman et al. 1965, Brinkman 1967, Brinkman and Smith 1968, Seidel and Rogers 1965, Seidel and Rogers 1966). In large portions of the Ozarks, shortleaf pine does not grow in pure stands but rather in mixes with various oak species. These mixes present unique challenges in finding the set of...

  8. Increasing cotton stand establishment in soils prone to soil crusting

    Science.gov (United States)

    Many factors can contribute to poor cotton stand establishment, and cotton is notorious for its weak seedling vigor. Soil crusting can be a major factor hindering cotton seedling emergence in many of the cotton production regions of the US and the world. Crusting is mainly an issue in silty soils ...

  9. Site classification for even-aged stands of western hemlock.

    Science.gov (United States)

    George H. Barnes

    1949-01-01

    In 1937 normal yield tables were compiled by Meyer for even-aged stands of Sitka spruce and Western hemlock. The basic data from which the tables were compiled were collected over the entire coastal range of the species, extending from southern Oregon through Washington end British Columbia to southeastern Alaska. Data were obtained from temporary sample plots...

  10. Dust transport and abrasion assessment within simulated standing vegetation

    Science.gov (United States)

    Crop residues are useful in protecting the top soil from depletion and abrasion due to wind erosion. A wind tunnel study was done to measure sand transport and abrasion energies within the simulated artificial standing vegetation. Wind profiles, relative abrasion energies and rates of sand dischar...

  11. Infrared differential absorption lidar for stand-off detection of ...

    Indian Academy of Sciences (India)

    2014-02-14

    Feb 14, 2014 ... bon dioxide laser-based differential absorption lidar (DIAL) system capable of stand-off detection of chemical clouds in ... technical details of trolley-mounted CO2 DIAL system and the data generated during the test and evaluation of this sensor using ... High-energy pulses of laser. Pramana – J. Phys., Vol.

  12. Handgrip Strength in Individuals with Long- Standing Type 2 ...

    African Journals Online (AJOL)

    Obnna

    Adequate muscle strength is required for optimum productivity and low muscle strength is a predictor of physical limitations. ... Long-standing type 2 diabetes mellitus seems to result in a decrease in handgrip strength in both male and female adults. ..... resistive training exercise programme can be instituted to decelerate the ...

  13. Free standing bulk metallic glass microcomponents: Tooling considerations

    DEFF Research Database (Denmark)

    Byrne, Cormac; Eldrup, Morten Mostgaard; Ohnuma, Masato

    2010-01-01

    Bulk metallic glasses have enormous potential for use in small-scale devices such as MEMS and biomedical components. Thermoplastic forging of free standing components poses challenges unlike those seen when forging crystalline materials. Central to these challenges is the simultaneous advantage/disadvantage...

  14. Standing in the Hallway Improves Students' Understanding of Conformity

    Science.gov (United States)

    Lawson, Timothy J.; Haubner, Richard R.; Bodle, James H.

    2013-01-01

    To help beginning psychology students understand how they are influenced by social pressures to conform, we developed a demonstration designed to elicit their conformity to a small group of students standing in the hallway before class. Results showed the demonstration increased students' recognition of their own tendency to conform, knowledge of…

  15. 29 CFR 452.88 - Resumption of good standing.

    Science.gov (United States)

    2010-07-01

    ... labor organization to deny the right to vote to those delinquent in paying their dues (with the... right to vote may be deferred within reasonable limits, a union may not create special classes of... 29 Labor 2 2010-07-01 2010-07-01 false Resumption of good standing. 452.88 Section 452.88 Labor...

  16. Early Adolescent Romantic Partner Status, Peer Standing, and Problem Behaviors

    Science.gov (United States)

    Miller, Shari; Lansford, Jennifer E.; Costanzo, Philip; Malone, Patrick S.; Golonka, Megan; Killeya-Jones, Ley A.

    2009-01-01

    This study examined associations among early adolescent romantic relationships, peer standing, problem behaviors, and gender as a moderator of these associations, in a sample of 320 seventh-grade students. Popular and controversial status youth were more likely to have a romantic partner, whereas neglected status youth were less likely to have a…

  17. Impaired standing balance : unraveling the underlying cause in elderly

    NARCIS (Netherlands)

    Pasma, Jantsje Henrieke

    2015-01-01

    Impaired balance is often seen in elderly and can result in impaired mobility and finally in falling. Failure of compensation strategies or deterioration of underlying systems involved in standing balance could result in impaired balance. To apply targeted interventions to improve balance, it is

  18. More standing and just as productive: Effects of a sit-stand desk intervention on call center workers’ sitting, standing, and productivity at work in the Opt to Stand pilot study

    Science.gov (United States)

    Chau, Josephine Y.; Sukala, William; Fedel, Karla; Do, Anna; Engelen, Lina; Kingham, Megan; Sainsbury, Amanda; Bauman, Adrian E.

    2015-01-01

    This study evaluated the effects of sit-stand desks on workers' objectively and subjectively assessed sitting, physical activity, and productivity. This quasi-experimental study involved one intervention group (n = 16) and one comparison group (n = 15). Participants were call center employees from two job-matched teams at a large telecommunications company in Sydney, Australia (45% female, 33 ± 11 years old). Intervention participants received a sit-stand desk, brief training, and daily e-mail reminders to stand up more frequently for the first 2 weeks post-installation. Control participants carried out their usual work duties at seated desks. Primary outcomes were workday sitting and physical activity assessed using ActivPAL or ActiGraph devices and self-report questionnaires. Productivity outcomes were company-specific objective metrics (e.g., hold time, talking time, absenteeism) and subjective measures. Measurements were taken at baseline, 1, 4, and 19 weeks post-installation. Intervention participants increased standing time after 1 week (+ 73 min/workday (95% CI: 22, 123)) and 4 weeks (+ 96 min/workday (95% CI: 41, 150)) post-intervention, while control group showed no changes. Between-group differences in standing time at one and 4 weeks were + 78 (95% CI: 9, 147) and + 95 min/workday (95% CI: 15, 174), respectively. Sitting time in the intervention group changed by − 64 (95% CI: − 125, − 2), − 76 (95% CI: − 142, − 11), and − 100 min/workday (95% CI: − 172, − 29) at 1, 4, and 19 weeks post-installation, respectively, while the control group showed no changes. No changes were observed in productivity outcomes from baseline to follow-up in either group. Sit-stand desks can increase standing time at work in call center workers without reducing productivity. PMID:26844191

  19. Relationship between morphologic somatotypes and standing posture equilibrium.

    Science.gov (United States)

    Allard, P; Nault, M L; Hinse, S; LeBlanc, R; Labelle, H

    2001-01-01

    Previous studies have identified height and weight as important factors affecting quiet standing stability but studies have not addressed body morphology as a global factor. Using anthropometric measurements, the morphologic somatotypes were defined in terms of body composition and structure. The aim of this study was to test the hypothesis that morphologic somatotypes were related to standing posture equilibrium in able-bodied girls. A total of 43 able-bodied girls having a mean age of 13.8 +/- 2.2 years participated in this study. Somatotype measurements were taken to determine their endomorphic, mesomorphic or ectomorphic components. Then, subjects were asked to stand still on a force platform for 64 s with their eyes opened, feet about 23 cm apart and arms aligned with the trunk. Afterwards, subjects were grouped based on the highest value of their somatotype component. There was no statistical difference in age, height and weight among the groups. The surface area of an ellipse delineated by the displacement of the centre of pressure (COP) was statistically larger (236.9 +/- 134.3 mm2) for the ectomorphs than for the endomorphs 137.7 +/- 71.4 mm2). The minor axis was longer (8.1 +/- 2.9 mm) for the ectomorphs than for the endomorphs (5.7 +/- 2.2 mm). The decrease in standing posture stability of the ectomorphic group was attributed to a relatively low muscle component, a high height weight ratio and an elevated position of the body centre of mass in this population of girls. Somatotypes should be considered when assessing standing posture in both able-bodied subjects and patients.

  20. Measuring Diagnostic Stand for Experimental Researches in Technology Machining

    Directory of Open Access Journals (Sweden)

    A. E. Dreval'

    2014-01-01

    Full Text Available The paper reviews applied techniques, methods, and structure of the control and measuring means to conduct experimental and scientific researches of cutting processes. Existing research methods in cutting the metals are divided by features, such as essence of methods, the number of records of physical indicators, the number of studied factors, duration of tests. The groups of methods are briefly characterized.The chair "Tool Engineering and Technologies" of BMSTU developed and made a diagnostic stand of control and measurements for conducting research activities in the field of materials processing technology by cutting to define rational technological decisions, when machining, and carry out an analysis of efficiency and economic feasibility of made decisions. The diagnostic stand contains modern the electronic equipment. Record of measuring parameters is made in real time with a possibility for visual representation of read results and mathematical and statistical processing of measurement results. The stand can be used in research laboratories of machine-building enterprises, laboratories of higher education institutions, and other scientific divisions.The paper presents a justification that the stand is reasonable to use for the following: completion and choice of rational cutting modes, workability assessment of new constructional materials, technical and operational characteristics of the processed surfaces, and operational properties of the cutting tools of various producers, choice of optimum geometrical parameters of the cutting tools and brands of the lubricant cooling technological means, as well as the energy consumption for the chosen machining process. The stand allows us to make an assessment of wear resistance and tribology-technical characteristics of tool materials, as well as an accuracy, rigidity, vibration stability of machines, both new and being in operation.

  1. Atmospheric deposition in coniferous and deciduous tree stands in Poland

    Science.gov (United States)

    Kowalska, Anna; Astel, Aleksander; Boczoń, Andrzej; Polkowska, Żaneta

    2016-05-01

    The objective of this study was to assess the transformation of precipitation in terms of quantity and chemical composition following contact with the crown layer in tree stands with varied species composition, to investigate the effect of four predominant forest-forming species (pine, spruce, beech, and oak) on the amount and composition of precipitation reaching forest soils, and to determine the sources of pollution in atmospheric precipitation in forest areas in Poland. The amount and chemical composition (pH, electric conductivity, alkalinity, and chloride, nitrate, sulfate, phosphate, ammonium, calcium, magnesium, sodium, potassium, iron aluminum, manganese, zinc, copper, total nitrogen, and dissolved organic carbon contents) of atmospheric (bulk, BP) and throughfall (TF) precipitation were studied from January to December 2010 on twelve forest monitoring plots representative of Polish conditions. The study results provided the basis for the determination of the fluxes of pollutants in the forest areas of Poland and allowed the comparison of such fluxes with values provided in the literature for European forest areas. The transformation of precipitation in the canopy was compared for different tree stands. The fluxes of substances in an open field and under canopy were influenced by the location of the plot, including the regional meteorological conditions (precipitation amounts), vicinity of the sea (effect of marine aerosols), and local level of anthropogenic pollution. Differences between the plots were higher in TF than in BP. The impact of the vegetation cover on the chemical composition of precipitation depended on the region of the country and dominant species in a given tree stand. Coniferous species tended to cause acidification of precipitation, whereas deciduous species increased the pH of TF. Pine and oak stands enriched precipitation with components that leached from the canopy (potassium, manganese, magnesium) to a higher degree than spruce and

  2. Effects of stand development and weather on monthly leaf biomass dynamics of a loblolly pine (Pinus taeda L.) stand

    Science.gov (United States)

    P.M. Dougherty; T.C. Hennessey; Stanley J. Zarnoch; P.t> Stenberg; R.T. Holeman; R.F. Witter

    1995-01-01

    Annual leaf biomass production, monthly needle accretion and monthly needlefall were measured in an 1l- to 17-year-old thinned stand of loblolly pine. Initial thinning levels were 7.8 m2 ha-1, 12.6 m2 ha-1, and 25.5 m2 ha-1...

  3. Tree regeneration and future stand development after bark beetle infestation and harvesting in Colorado lodgepole pine stands

    Science.gov (United States)

    Byron J. Collins; Charles C. Rhoades; Robert M. Hubbard; Michael A. Battaglia

    2011-01-01

    In the southern Rocky Mountains, current mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreaks and associated harvesting have set millions of hectares of lodgepole pine (Pinus contorta var. latifolia Engelm. ex Wats.) forest onto new stand development trajectories. Information about immediate, post-disturbance tree regeneration will provide insight on...

  4. Clinical ketosis and standing behavior in transition cows.

    Science.gov (United States)

    Itle, A J; Huzzey, J M; Weary, D M; von Keyserlingk, M A G

    2015-01-01

    Ketosis is a common disease in dairy cattle, especially in the days after calving, and it is often undiagnosed. The objective of this study was to compare the standing behavior of dairy cows with and without ketosis during the days around calving to determine if changes in this behavior could be useful in the early identification of sick cows. Serum β-hydroxybutyrate (BHBA) was measured in 184 cows on a commercial dairy farm twice weekly from 2 to 21d after calving. Standing behavior was measured from 7d before calving to 21d after calving using data loggers. Retrospectively, 15 cows with clinical ketosis (3 consecutive BHBA samples >1.2mmol/L and at least one sample of BHBA >2.9mmol/L) were matched with 15 nonketotic cows (BHBA ketosis occurred 4.5±2.1d after calving. Total daily standing time was longer for clinically ketotic cows compared with nonketotic cows during wk -1 (14.3±0.6 vs. 12.0±0.7h/d) and on d 0 (17.2±0.9 vs. 12.7±0.9h/d) but did not differ during the other periods. Clinically ketotic cows exhibited fewer standing bouts compared with nonketotic cows on d 0 only (14.6±1.9 vs. 20.9±1.8bouts/d). Average standing bout duration was also longer for clinically ketotic cows on d 0 compared with nonketotic cows [71.3min/bout (CI: 59.3 to 85.5) vs. 35.8min/bout (CI: 29.8 to 42.9)] but was not different during the other periods. Differences in standing behavior in the week before and on the day of calving may be useful for the early detection of clinical ketosis in dairy cows. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Transient physiological responses of planting frozen root plugs of Douglas-fir seedlings

    Science.gov (United States)

    M. Anisul Islam; Douglass F. JAcobs; Kent G. Apostol; R. Kasten Dumroese

    2008-01-01

    Short-term physiological responses of planting frozen (FR) and rapidly thawed (TR) root plugs of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were examined through time series (0 h, 6 h, 12 h, 1 day, 3 days, and 7 days) measurements in two separate experiments: 10 C day: 6 C night, RH 75% and 30 C day: 20 C night, RH 50%, respectively...

  6. Modular photovoltaic stand-alone systems: Phase 1

    Science.gov (United States)

    Naff, G. J.; Marshall, N. A.

    1983-01-01

    A family of modular stand-alone power systems that covered the range in power level from 1 kw to 14 kw was developed. Products within this family were required to be easily adaptable to different environments and applications, and were to be both reliable and cost effective. Additionally, true commonality in hardware was to be exploited, and unnecessary recurrence of design and development costs were to be minimized; thus improving hardware availability. Assurance of compatibility with large production runs, was also an underlying program goal. A secondary objective was to compile, evaluate, and determine the economic and technical status of available, and potentially available, technology options associated with the balance of systems (BOS) for stand-along photovoltaic (PV) power systems. The secondary objective not only directly supported the primary but additionally contributed to the definition and implementation of the BOS cost reduction plan.

  7. Stand pentru încercarea grinzilor precomprimate U 37m

    Directory of Open Access Journals (Sweden)

    Mircea Păstrav

    2011-03-01

    Full Text Available As part of conformity certification process of prefabricated beams used for bridges and viaducts on Transylvania Motorway, a prestressed concrete U-shaped beam of 37.10 m span with superior slab cast in situ was subjected to a resistance test. Due to beam overall dimensions of 3.30 x 2.50 x 37.10 m and to the important forces which have to be applied it has been necessary to build an adequate stand right near the precast site. Paper briefly presents the mechanical, technological, economical and work safety requirements, the design and the actual implementation of the one of the largest testing stands made în our country.

  8. Models for a stand-alone PV system

    DEFF Research Database (Denmark)

    Hansen, A.D.; Sørensen, Poul Ejnar; Hansen, L.H.

    2001-01-01

    This report presents a number of models for modelling and simulation of a stand-alone photovoltaic (PV) system with a battery bank verified against a system installed at Risø National Laboratory. The work has been supported by the Danish Ministry ofEnergy, as a part of the activities in the Solar...... Energy Centre Denmark. The study is carried out at Risø National Laboratory with the main purpose to establish a library of simple mathematical models for each individual element of a stand-alone PVsystem, namely solar cells, battery, controller, inverter and load. The models for PV module and battery...... are based on the model descriptions found in the literature. The battery model is developed at UMASS and is known as the Kinetic Battery Model(KiBaM). The other component models in the PV system are based on simple electrical knowledge. The implementation is done using Matlab/Simulink, a simulation program...

  9. The one-leg standing radiograph: An improved technique to evaluate the severity of knee osteoarthritis.

    Science.gov (United States)

    Pinsornsak, P; Naratrikun, K; Kanitnate, S; Sangkomkamhang, T

    2016-09-01

    The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis was evaluated using the joint space width and Kellgren-Lawrence (KL) radiographic classification. The t-test was used for statistical analysis. The mean medial joint space width found in the one-leg and in the both-legs standing view were measured at 1.8 mm and 2.4 mm, respectively (p leg standing views, respectively. No changes for KL IV osteoarthritis diagnoses have been found between both- and one-leg standing views. One-leg standing radiographs better represent joint space width than both-legs standing radiographs. 32% of both-legs standing radiographs have changed the KL grading to a more severe grade than that in the one-leg standing radiographs.Cite this article: P. Pinsornsak, K. Naratrikun, S. Kanitnate, T. Sangkomkamhang. The one-leg standing radiograph: An improved technique to evaluate the severity of knee osteoarthritis. Bone Joint Res 2016;5:436-441. DOI: 10.1302/2046-3758.59.BJR-2016-0049.R1. © 2016 Pinsornsak et al.

  10. Relationships among environmental variables and distribution of tree species at high elevation in the Olympic Mountains

    Science.gov (United States)

    Woodward, Andrea

    1998-01-01

    Relationships among environmental variables and occurrence of tree species were investigated at Hurricane Ridge in Olympic National Park, Washington, USA. A transect consisting of three plots was established down one north-and one south-facing slope in stands representing the typical elevational sequence of tree species. Tree species included subalpine fir (Abies lasiocarpa), Douglas-fir (Pseudotsuga menziesii), mountain hemlock (Tsuga mertensiana), and Pacific silver fir (Abies amabilis). Air and soil temperature, precipitation, and soil moisture were measured during three growing seasons. Snowmelt patterns, soil carbon and moisture release curves were also determined. The plots represented a wide range in soil water potential, a major determinant of tree species distribution (range of minimum values = -1.1 to -8.0 MPa for Pacific silver fir and Douglas-fir plots, respectively). Precipitation intercepted at plots depended on topographic location, storm direction and storm type. Differences in soil moisture among plots was related to soil properties, while annual differences at each plot were most often related to early season precipitation. Changes in climate due to a doubling of atmospheric CO2 will likely shift tree species distributions within, but not among aspects. Change will be buffered by innate tolerance of adult trees and the inertia of soil properties.

  11. Swiss Needle Cast in Western Oregon Douglas-Fir Plantations: 20‐Year Monitoring Results

    Directory of Open Access Journals (Sweden)

    Gabriela Ritóková

    2016-07-01

    Full Text Available Swiss needle cast (SNC, a foliar disease specific to Douglas-fir (Pseudotsuga menziesii, is caused by an endemic Ascomycete fungus (Phaeocryptopus gaeumannii. In the late 1980s and early 1990s significant symptoms began to appear in coastal Oregon, and these have been associated with the planting of Douglas-fir in the Sitka spruce zone, leaf wetness during potential spore dispersal in May–August, and mild winter temperature. The first annual aerial survey was initiated in 1996 and has continued through 2015, which indicates a significant increase in area of visible symptoms from the air, increasing from 53,050 ha in 1996 to 238,705 ha in 2015. Monitoring plots in the NW Oregon Coast Range verified impacts of SNC on tree growth and productivity, with growth reductions averaging about 23% in the epidemic area linked to needle retention. A series of monitoring plots was set up in the western Cascade Mountains of Oregon and 590 10–23-year old Douglas-fir trees in 59 stands were tracked for 10 years, measured in 2001, 2006, and 2011. No measureable growth impacts were noted in this region of Oregon. A new plot network is being installed throughout the Oregon and southwest Washington coastal ranges as a means of monitoring future disease impact and providing framework for additional studies.

  12. Building Resilience into Sitka Spruce (Picea sitchensis (Bong. Carr. Forests in Scotland in Response to the Threat of Climate Change

    Directory of Open Access Journals (Sweden)

    Andrew D. Cameron

    2015-02-01

    Full Text Available It is expected that a warming climate will have an impact on the future productivity of European spruce forests. In Scotland, Sitka spruce (Picea sitchensis (Bong. Carr. dominates the commercial forestry sector and there is growing pressure to develop alternative management strategies to limit potential economic losses through climate change. This review considers management options to increase the resilience of Sitka spruce dominated forests in Scotland. Given the considerable uncertainty over the potential long-term impacts of climate change, it is recommended that Sitka spruce should continue to be planted where it already grows well. However, new planting and restocking should be established in mixtures where silviculturally practicable, even if no-thin regimes are adopted, to spread future risks of damage. Three potentially compatible species with Sitka spruce are western hemlock (Tsuga heterophylla (Raf. Sarg., grand fir (Abies grandis (Lamb. Lindl. and Douglas fir (Pseudotsuga menziesii (Mirb. Franco and all form natural mixtures in its native range in North America. The predicted windier climate will require a range of management inputs, such as early cutting of extraction racks and early selective thinning, to improve stability. The potential to improve resilience to particularly abiotic damage through transforming even-aged stands into irregular structures and limiting the overall size of the growing stock is discussed.

  13. Astronaut Harrison Schmitt standing next to boulder during third EVA

    Science.gov (United States)

    1973-01-01

    Scientist-Astronaut Harrison H. Schmitt is photographed standing next to a huge, split boulder during the third Apollo 17 extravehicular activity (EVA-3) at the Taurus-Littrow landing site on the Moon. The lunar rover, which transported Schmitt and Eugene A. Cernan, mission commander, to this extravehicular station from their Lunar Module, is seen in the background. Schmitt is the Apollo 17 lunar module pilot. The mosaic is made from two frames from Apollo 17 Hasselblad magaine 140.

  14. Experimental investigation of stress wave propagation in standing trees

    Science.gov (United States)

    Houjiang Zhang; Xiping Wang; Juan Su

    2011-01-01

    The objective of this study was to investigate how a stress wave travels in a standing tree as it is introduced into the tree trunk through a mechanical impact. A series of stress wave time-of-flight (TOF) data were obtained from three freshly-cut red pine (Pinus resinosa Ait.) logs by means of a two-probe stress wave timer. Two-dimensional (2D) and three-dimensional (...

  15. DETERMINING STAND PARAMETERS FROM UAS-BASED POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    V. Yilmaz

    2016-06-01

    Full Text Available In Turkey, forest management plans are produced by terrestrial surveying techniques for 10 or 20 year periods, which can be considered quite long to maintain the sustainability of forests. For a successful forest management plan, it is necessary to collect accurate information about the stand parameters and store them in dynamic and robust databases. The position, number, height and closure of trees are among the most important stand parameters required for a forest management plan. Determining the position of each single tree is challenging in such an area consisting of too many interlocking trees. Hence, in this study, an object-based tree detection methodology has been developed in MATLAB programming language to determine the position of each tree top in a highly closed area. The developed algorithm uses the Canopy Height Model (CHM, which is computed from the Digital Terrain Model (DTM and Digital Surface Model (DSM generated by using the point cloud extracted from the images taken from a UAS (Unmanned Aerial System. The heights of trees have been determined by using the CHM. The closure of the trees has been determined with the written MATLAB script. The results show that the developed tree detection methodology detected more than 70% of the trees successfully. It can also be concluded that the stand parameters may be determined by using the UAS-based point clouds depending on the characteristics of the study area. In addition, determination of the stand parameters by using point clouds reduces the time needed to produce forest management plans.

  16. Relocate GTMO Detainees to Stand Trial in the United States

    Science.gov (United States)

    2011-03-16

    the 1998 terrorist bombings of the United States Embassies in Nairobi, Kenya, and Dar es Salaam , Tanzania. Expect...St ra te gy R es ea rc h Pr oj ec t RELOCATE GTMO DETAINEES TO STAND TRIAL IN THE UNITED STATES BY LIEUTENANT COLONEL REX D. LYNNE...options for the disposition of Guantanamo detainees and others captured by the United States.2 On 20 May 2009, in a bi-partisan vote, Congress denied the

  17. Penerapan Analisis Diskriminan dalam Pembedaan Kelas Umur Tegakan Pinus (Discriminant Analysist for Stand Class Age Distinction of Pine Stand

    Directory of Open Access Journals (Sweden)

    Priyanto .

    2011-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} This  study  describes the use of discriminant anylisis for pine (Pinus spp. stand class age distinction.    Aim of this  study were (1 to arrange stand age class based on variable of aerial photograph by non hierarchy cluster analysis,  and (2 to find out aerial  photograph variable contribute to stand age class distinction by discriminant analysis.    Data used in study was taken from  a  research  conducted by Adi (1998.   Pinus stand was located  in KPH Bandung Utara, West Java. The variable of aerial photograph that used in this analysis were tone, shape, texture, topography, pattern, crown, diameter and height. The result showed that validation analysis of discriminant function was significant.  Therefore, this function was applicable for grouping new object to stand age class based on discriminant score. Keywords: cluster analysis, discriminat analysis, stand age class, discriminant score

  18. Radiation components of beech stands in southwest Germany

    Energy Technology Data Exchange (ETDEWEB)

    Holst, T.; Mayer, H. [Meteorological Inst., Univ. of Freiburg (Germany)

    2005-04-01

    Within the framework of an interdisciplinary project on the impact of climate and forest management on beech dominated deciduous forests, forest meteorological measurements are carried out within and above different beech stands (Fagus sylvatica L.) on opposite slopes of a narrow valley located in the Swabian Jura mountain range (south-west Germany). Referring to test plots on both slopes, the following cycles of radiation components are discussed: (1) Monthly mean values of transmission and extinction of global solar irradiance, photosynthetically active radiation as well as UV-A and UV-B radiation through the canopy, (2) diurnal courses of surface albedo {alpha}, net short-wave radiation K{sup *}, net long-wave radiation L{sup *} and net all-wave radiation Q{sup *} for a cloudless day in March (leafless period) and a cloudless day in July (fully-leaved period) above and below the canopy of different beech stands, and (3) monthly mean values of {alpha}, K{sup *}, L{sup *} and Q{sup *} for the same stand conditions as for (2). The results point out the combined impact on the investigated radiation components emanating from seasonally variable canopy density (quantified by the plant area index), exposure and sun elevation. (orig.)

  19. Robot-supported assessment of balance in standing and walking.

    Science.gov (United States)

    Shirota, Camila; van Asseldonk, Edwin; Matjačić, Zlatko; Vallery, Heike; Barralon, Pierre; Maggioni, Serena; Buurke, Jaap H; Veneman, Jan F

    2017-08-14

    Clinically useful and efficient assessment of balance during standing and walking is especially challenging in patients with neurological disorders. However, rehabilitation robots could facilitate assessment procedures and improve their clinical value. We present a short overview of balance assessment in clinical practice and in posturography. Based on this overview, we evaluate the potential use of robotic tools for such assessment. The novelty and assumed main benefits of using robots for assessment are their ability to assess 'severely affected' patients by providing assistance-as-needed, as well as to provide consistent perturbations during standing and walking while measuring the patient's reactions. We provide a classification of robotic devices on three aspects relevant to their potential application for balance assessment: 1) how the device interacts with the body, 2) in what sense the device is mobile, and 3) on what surface the person stands or walks when using the device. As examples, nine types of robotic devices are described, classified and evaluated for their suitability for balance assessment. Two example cases of robotic assessments based on perturbations during walking are presented. We conclude that robotic devices are promising and can become useful and relevant tools for assessment of balance in patients with neurological disorders, both in research and in clinical use. Robotic assessment holds the promise to provide increasingly detailed assessment that allows to individually tailor rehabilitation training, which may eventually improve training effectiveness.

  20. Modified technique for common carotid artery transposition in standing horses.

    Science.gov (United States)

    Tapio, Heidi; Argüelles, David; Gracia-Calvo, Luis A; Raekallio, Marja

    2017-01-01

    To describe a modified technique for permanent translocation of the common carotid artery (CCA) to a subcutaneous position in standing horses. Experimental study. Healthy adult Standardbred and Warmblood horses (n = 8). Surgery was performed with the horses standing under sedation and with local anesthesia. A combination of previously described techniques was used modifying the approach and closure of the incision. The right CCA was approached through a linear skin incision dorsal and parallel to the jugular vein and through the brachiocephalicus and omohyoideus muscles. The artery was dissected free of its sheath and elevated to the skin incision with Penrose drains. The brachiocephalicus muscle was sutured in two layers underneath the artery leaving it in a subcutaneous position. The horses were allowed to heal for 3 weeks prior to catheterization of the artery. The transposed CCA was successfully used for repeated catheterization in six of eight horses for a period of 10 weeks. None of the horses had intraoperative complications. Two horses developed mild peri-incisional edema that resolved spontaneously. Right-sided laryngeal hemiplegia was observed endoscopically in two horses postoperatively. Two horses developed complications (surgical site infection and excessive periarterial fibrosis) that compromised the patency of the CCA and precluded catheterization. Permanent translocation of the CCA in standing horses was successful in six out of eight horses. Upper airway endoscopy postoperatively may be warranted as laryngeal hemiplegia may ensue. © 2016 The American College of Veterinary Surgeons.

  1. Effects of sound on postural stability during quiet standing.

    Science.gov (United States)

    Park, Sung Ha; Lee, Kichol; Lockhart, Thurmon; Kim, Sukwon

    2011-12-15

    Loss of postural stability can increase the likelihood of slips and falls in workplaces. The present study intended to extend understanding of the effects of frequency and pressure level of sound on postural stability during standing. Eleven male subjects participated. Standing on a force platform, the subjects' center of pressures were measured under different combinations of pressure level and frequency of the sound. Variables such as the position variability of COP and the length of postural sway path in anterior-posterior (AP) and medio-lateral (ML) direction were evaluated. Subjective ratings of perceived disturbance at each experimental condition were also obtained using a 7-point rating scale. Results showed that the length of sway path and the position variability of COP increased as the frequency of sound increased in posterior-anterior axis. The effect of sound pressure level, however, was not significant on both the postural sway length and the position variability of COP. These results suggested substantial disturbance of standing balance system among subjects exposed to high frequency noise. The results implied that physical workers should be alerted that their abilities of postural balance could be degraded significantly as disturbance caused by a sound existed.

  2. Effects of Sound on Postural Stability during Quiet Standing

    Directory of Open Access Journals (Sweden)

    Park Sung

    2011-12-01

    Full Text Available Abstract Loss of postural stability can increase the likelihood of slips and falls in workplaces. The present study intended to extend understanding of the effects of frequency and pressure level of sound on postural stability during standing. Eleven male subjects participated. Standing on a force platform, the subjects' center of pressures were measured under different combinations of pressure level and frequency of the sound. Variables such as the position variability of COP and the length of postural sway path in anterior-posterior (AP and medio-lateral (ML direction were evaluated. Subjective ratings of perceived disturbance at each experimental condition were also obtained using a 7-point rating scale. Results showed that the length of sway path and the position variability of COP increased as the frequency of sound increased in posterior-anterior axis. The effect of sound pressure level, however, was not significant on both the postural sway length and the position variability of COP. These results suggested substantial disturbance of standing balance system among subjects exposed to high frequency noise. The results implied that physical workers should be alerted that their abilities of postural balance could be degraded significantly as disturbance caused by a sound existed.

  3. Analysis of Human Standing Balance by Largest Lyapunov Exponent

    Directory of Open Access Journals (Sweden)

    Kun Liu

    2015-01-01

    Full Text Available The purpose of this research is to analyse the relationship between nonlinear dynamic character and individuals’ standing balance by the largest Lyapunov exponent, which is regarded as a metric for assessing standing balance. According to previous study, the largest Lyapunov exponent from centre of pressure time series could not well quantify the human balance ability. In this research, two improvements were made. Firstly, an external stimulus was applied to feet in the form of continuous horizontal sinusoidal motion by a moving platform. Secondly, a multiaccelerometer subsystem was adopted. Twenty healthy volunteers participated in this experiment. A new metric, coordinated largest Lyapunov exponent was proposed, which reflected the relationship of body segments by integrating multidimensional largest Lyapunov exponent values. By using this metric in actual standing performance under sinusoidal stimulus, an obvious relationship between the new metric and the actual balance ability was found in the majority of the subjects. These results show that the sinusoidal stimulus can make human balance characteristics more obvious, which is beneficial to assess balance, and balance is determined by the ability of coordinating all body segments.

  4. Ageing with long-standing hearing impairment and deafness.

    Science.gov (United States)

    Gething, L

    2000-09-01

    Until recently, ageing with a long-standing disability had not been a major consideration for governments around the world. Policy and planning for this substantial subgroup had not kept abreast with developments in regard to the growing numbers of older people in general. Consultations held in Australia provided information and recommendations for use by governments and service agencies. The focus was on the viewpoints of consumers. This article reports results for people with long-standing deafness and hearing impairment. It is believed that disadvantages throughout life act to restrict freedom of choice and well-being in old age. Important factors perceived to underlie disadvantage include lifelong restricted access to the opportunities afforded by education and employment and their concomitant effects on the ability to develop the skills, attitudes and knowledge necessary for independence in old age; attitudes of others (including service providers); and the complexity and inflexibility of service systems. However, there are positive aspects. Comparison with published reports about people who acquired hearing loss as a result of the ageing process suggests that people with long-standing disability have learned to live with their situation. In contrast, people whose loss was associated with ageing often report emotional issues and isolation.

  5. Selection of optimal muscle set for 16-channel standing neuroprosthesis

    Science.gov (United States)

    Gartman, Steven J.; Audu, Musa L.; Kirsch, Robert F.; Triolo, Ronald J.

    2009-01-01

    The Case Western Reserve University/Department of Veterans Affairs 8-channel lower-limb neuroprosthesis can restore standing to selected individuals with paraplegia by application of functional electrical stimulation. The second generation of this system will include 16 channels of stimulation and a closed-loop control scheme to provide automatic postural corrections. This study used a musculoskeletal model of the legs and trunk to determine which muscles to target with the new system in order to maximize the range of postures that can be statically maintained, which should increase the system’s ability to provide adequate support to maintain standing when the user’s posture moves away from a neutral stance, either by an external disturbance or a volitional change in posture by the user. The results show that the prime muscle targets should be the medial gastrocnemius, tibialis anterior, vastus lateralis, semimembranosus, gluteus maximus, gluteus medius, adductor magnus, and erector spinae. This set of 16 muscles supports 42 percent of the standing postures that are attainable by the nondisabled model. Coactivation of the lateral gastrocnemius and peroneus longus with the medial gastrocnemius and of the peroneus tertius with the tibialis anterior increased the percentage of feasible postures to 71 percent. PMID:16847793

  6. Oxygen Consumption While Standing with Unstable Shoe Design

    Directory of Open Access Journals (Sweden)

    Gasser Benedikt A.

    2014-09-01

    Full Text Available Purpose. This study explored the effects of unstable shoe design on oxygen consumption. Methods. Oxygen consumption (VO2 and heart rate (HR were measured in 16 individuals while barefoot, wearing unstable shoes (Masai Barefoot Technology and wearing conventional sport shoes while standing and walking on a treadmill and for 5 individuals while walking around a 400 m track. Results. When wearing the MBT shoes, a significant (p < 0.01 increase of 9.3 ± 5.2% in VO2 was measured while standing quietly for 6 min. No differences in VO2 and HR were observed between the MBT shoes or weight-adjusted conventional shoes (to match the weight of the MBT shoes while walking on a treadmill. However, significant increases (p < 0.01 in VO2 (4.4 ± 8.2% and HR (3.6 ± 7.3% were observed for the MBT shoes compared with being barefoot. No significant differences in VO2 and HR were recorded while walking around a 400 m track either with MBT shoes, weight-adjusted conventional shoes or barefoot. Nonetheless, a comparison of the MBT shoes with barefoot revealed a tendency for VO2 to be higher when wearing the MBT shoes (7.1 ± 6.5%, p < 0.1 although HR was not significantly affected. Conclusions. The unstable shoe design predominantly effects oxygen consumption while standing, most likely due to increased muscle activity of the lower extremities.

  7. Emergent aquatics: stand establishment, management, and species screening

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, D.C.; Andrews, N.J.; Dubbe, D.R.; Garver, E.G.; Penko, M.; Read, P.E.; Zimmerman, E.S.

    1982-11-01

    Several emergent aquatic species have been identified as potential biomass crops, including Typha spp. (cattail), Scirpus spp. (rush), Sparganium spp. (bur reed), and Phragmites (reed). This report discusses first year results from studies of stand establishment and management, Typha nutrient requirements, wetland species yield comparisons, and Typha micropropagation. In a comparison of the relative effectiveness of seed, seedlings, and rhizomes for stand establishment, rhizomes appeared to be more consistent and productive under a wire variety of conditions. Both rhizomes and seedling established plots grew successfully on excavated peatland sites. First season results from a multiyear fertilizer rate experiment indicate that fertilizer treatment resulted in significantly increased tissue nutrient concentrations which should carry over into subsequent growing seasons. Shoot density and belowground dry weight were also significantly increased by phosphorus + potassium and potassium applications, respectively. First season yields of selected wetland species from managed paddies generally were comparable to yields reported from natural stands. Several particularly productive clones of Typha spp. have been identified. A method of establishing Typha in tissue culture is described.

  8. Influence of mass imperfections on the evolution of standing waves in slowly rotating spherical bodies

    CSIR Research Space (South Africa)

    Shatalov, MY

    2011-01-01

    Full Text Available Standing waves can exist as stable vibrating patterns in perfect structures such as spherical bodies, and inertial rotation of the body causes precession (Bryan’seffect). However, an imperfection such as light mass anisotropy destroys the standing...

  9. Inverter and Motor Model Adaptation at Stand-Still Using Reference Voltages and Measured Currents

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Tønnes, M.; Knudsen, Morten

    1995-01-01

    A model adaptation method for estimating the electrical parameters of an induction motor at stand-still is described.......A model adaptation method for estimating the electrical parameters of an induction motor at stand-still is described....

  10. Individual-tree diameter growth model for managed, even-aged, upland oak stands

    Science.gov (United States)

    Donald E. Hilt

    1983-01-01

    A distance-independent, individual-tree diameter growth model was developed for managed, even-aged, upland oak stands. The 5-year basal-area growth of individual trees is first modeled as a function of dbh squared for given stands. Parameters from these models are then modeled as a function of mean stand diameter, percent stocking of the stand, and site index. A...

  11. Evaluation of beech stand condition based on the basic growth elements

    OpenAIRE

    Vučković Milivoj; Stajić Branko

    2003-01-01

    The state of a beech stand is analyzed from the aspect of stability and production level. The arguments are presented for the need of the objective definition of the stand condition by the criteria based on the characteristics of stand growth elements. This contributes to integral management procedures and their verification in the aim of optimal and stabile production. The study results show that there can be significant deviations from the optimal stand condition regarding the number of tre...

  12. The risk of varicose veins in standing female workers

    Directory of Open Access Journals (Sweden)

    Tony Hidayat

    2013-07-01

    Full Text Available AbstrakLatar belakang:Varises sering terjadi pada karyawan yang harus bekerja dalam posisi kerja berdiri. Tujuan penelitian ini untuk mengetahui beberapa faktor risiko terhadap varises tungkai dan atau kaki di antara pekerja perempuan. Metode:Penelitian potong lintang ini dilakukan pada Januari-Maret 2010. Sampel penelitian yang dipilih secara purposif yang memenuhi kriteria inklusi penelitian di antara pekerja perempuan perlu bekerja dalam  posisi  kerja  berdiri.  Data  dikumpulkan  dengan  wawancara,  pemeriksaan  fisik  dan  observasi posisi kerja berdiri. Pengolahan data untuk menentukan faktor dominan terhadap varises menggunakan pendekatan risiko relatif.Hasil:Dari 152 karyawan yang terdapat 111 yang bersedia mengikuti penelitian, dan yang menderita varises tungkai dan atau kaki sebanyak 52,3% (53 orang. Sebagian besar responden berusia 18-35 tahun, memiliki masa kerja 3-17 tahun, bekerja dalam posisi kerja banyak berdiri. Sebagian kecil responden memiliki riwayat varises di dalam keluarga (13,51%, memakai kontrasepsi oral (11,71%, memiliki kebiasaan olah raga (18,02% dan memakai sepatu hak tinggi (11,71%. Faktor umur, pemakaian kontrasepsi oral, pemakaian sepatu hak tinggi, kebiasaan olah raga, posisi kerja berdiri, tempat kerja, dan masa kerja tidak berhubungan dengan varises tungkai dan atau kaki. Karyawan yang mempunyai dibandingkan dengan yang tidak mempunyai riwayat keluarga varises, berisiko 69% lebih tinggi menderita varises [risiko relatif (RR = 1,69; P = 0.121]. Kesimpulan:Karyawan yang mempunyai riwayat keluarga varises berisiko lebih tinggi menderita varises. (Health Science Indones 2013;1:47-50 Kata kunci:varises, posisi kerja berdiriAbstractBackground: Varicose veins often occur in employees who have to work in a position of standing work. The purpose of this study to determine risk factors for varicose veins and leg or foot among women workers.Methods: In this cross-sectional study in January-March 2010 the

  13. Quantification of lower extremity physical exposures in various combinations of sit/stand time duration associated with sit-stand workstation.

    Science.gov (United States)

    Pei, Huining; Yu, Suihuai; Babski-Reeves, Kari; Chu, Jianjie; Qu, Min; Tian, Baozhen; Li, Wenhua

    2017-05-16

    Sit-stand workstations are available for office work purposes but there is a dearth of quantitative evidence to state benefits for lower limb outcomes while using them. And there are no guidelines on what constitutes appropriate sit/stand time duration. The primary aim of this study has been to compare muscle activity and perceived discomfort in the lower extremity during various combinations of sit/stand time duration associated with a sit-stand workstation separately and to evaluate the effects of the sit-stand workstation on the lower extremity during the text entry task. During the 5 days, all participants completed a 2-h text entry task each day for various sit/stand time duration combinations as follows: 5/25 min, 10/20 min, 15/15 min, 20/10 min, 25/5 min. Lower extremity muscular exposure of 12 male and 13 female participants was collected at 8 sites by surface electromyography and body discomfort was calculated by a questionnaire under those 5 conditions. Results have demonstrated that lower extremity muscle activity has been significantly varied among the 5 sit/stand time duration groups. Perceived level of discomfort (PLD) has not differed significantly for 9 out of 10 body parts. The muscle activity of the thigh region was influenced by sit/stand time duration significantly. Ergonomic exposures of lower extremity when using a sit-stand workstation were increased, particularly during the long time standing posture. Results indicate that body mass index (BMI) and gender were not significant factors in this study. Combination of sit/stand time duration 25/5 min appears to show positive effects on relief of muscle exposure of back of thigh in the shifts of sitting and standing work position. Med Pr 2017;68(3):315-327.

  14. Early development of postural adjustments in standing with and without support

    NARCIS (Netherlands)

    Hedberg, Asa; Schmitz, Christina; Forssberg, Hans; Hadders-Algra, Mijna

    This study investigates the early development of postural adjustments during external perturbations in two different standing positions: standing with support and standing without support. The aim of the study was to assess a group of 13 infants four times during the period in life when independent

  15. Stand density guides for predicting growth of forest tress of southwest Idaho

    Science.gov (United States)

    Douglas D. Basford; John Sloan; Joy Roberts

    2010-01-01

    This paper presents a method for estimating stand growth from stand density and average diameter in stands of pure and mixed species in Southwest Idaho. The methods are adapted from a model developed for Douglas-fir, ponderosa pine, and lodgepole pine on the Salmon National Forest. Growth data were derived from ponderosa pine increment cores taken from sample plots on...

  16. 29 CFR 401.15 - Member or member in good standing.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 2 2010-07-01 2010-07-01 false Member or member in good standing. 401.15 Section 401.15...-MANAGEMENT STANDARDS MEANING OF TERMS USED IN THIS SUBCHAPTER § 401.15 Member or member in good standing. Member or member in good standing, when used in reference to a labor organization, includes any person...

  17. Comparison of three sampling methods in the characterization of cork oak stands for management purpose

    NARCIS (Netherlands)

    Paulo, M.J.; Tomé, M.; Otten, A.; Stein, A.

    2005-01-01

    The cork oak (Quercus suber L.) is an evergreen oak that has the ability to produce a continuous layer of cork tissue which regenerates after being removed. Cork oak stands can be diverse in structure. Young stands are often regularly spaced, whereas older stands usually show clustering and can be

  18. The Control of Posture in Newly Standing Infants is Task Dependent

    Science.gov (United States)

    Claxton, Laura J.; Melzer, Dawn K.; Ryu, Joong Hyun; Haddad, Jeffrey M.

    2012-01-01

    The postural sway patterns of newly standing infants were compared under two conditions: standing while holding a toy and standing while not holding a toy. Infants exhibited a lower magnitude of postural sway and more complex sway patterns when holding the toy. These changes suggest that infants adapt postural sway in a manner that facilitates…

  19. The impact of modern gin stands on cotton fiber and seed quality

    Science.gov (United States)

    This study examined fiber length reductions, short fiber content, fiber neps, and cottonseed damage associated with modern saw gin stands. The two-year study used five gin stands of differing type and manufacture. The gin stands were classified as either "high-capacity" (HC) or "super-high-capacity"...

  20. Effects of peanut stand uniformity and herbicide regime on weed management and yield

    Science.gov (United States)

    Crop stand directly affects ability of any crop to compete with weeds. To capture this form of cultural weed control, final crop stands need to be uniform. Peanut stands are frequently non-uniform, despite the use of precision vacuum planters. Trials were conducted from 2009 through 2011 in Tifto...

  1. Seeds in the Organic Layers and Soil of Four Beech-Birch-Maple Stands

    Science.gov (United States)

    Raymond E. Graber; Donald F. Thompson

    1978-01-01

    Forest floor samples were collected in northern hardwood stands 5, 38, 95, and 200+ years old. The seeds contained in these samples were germinated in a greenhouse. Thirty-five species of herbs, shrubs, and trees were identified. The largest number of species, 23, were from the 5-year-old stand. The oldest stand had the fewest species, 17. Rubus and...

  2. Harvesting Impacts on Soil Properties and Tree Regeneration in Pure and Mixed Aspen Stands

    Science.gov (United States)

    Melissa J. Arikian; Kiaus J. Peuttmann; Alaina L. Davis; George E. Host; John Zasada

    1999-01-01

    Impacts of clearcutting and selective harvesting on pure aspen/mixed aspen hardwood stands were examined in northern Minnesota. We studied these impacts on 18 stands, which were harvested 4 to 11 years ago and received no further treatment. In each stand, residual composition, soil compaction, and tree regeneration were determined along a gradient of disturbance in the...

  3. Logging damage in thinned, young-growth true fir stands in California and recommendations for prevention.

    Science.gov (United States)

    Paul E. Aho; Gary Fiddler; Mike. Srago

    1983-01-01

    Logging-damage surveys and tree-dissection studies were made in commercially thinned, naturally established young-growth true fir stands in the Lassen National Forest in northern California. Significant damage occurred to residual trees in stands logged by conventional methods. Logging damage was substantially lower in stands thinned using techniques designed to reduce...

  4. A stand-development approach to oak afforestation in the lower Mississippi alluvial valley

    Science.gov (United States)

    Brian Roy Lockhart; Emile Gardiner; Theodor Leininger; John Stanturf

    2008-01-01

    Oak (Quercus spp.) afforestation in the Lower Mississippi Alluvial Valley has involved planting 1-year-old bareroot seedlings on a relatively wide spacing in single-species stands or planting light-seeded species with oaks to form mixed-species stands. In the former case, the developing single-species stands have limited future management options...

  5. 28 CFR 58.4 - Qualifications for appointment as standing trustee and fiduciary standards.

    Science.gov (United States)

    2010-07-01

    ... standing trustee and fiduciary standards. 58.4 Section 58.4 Judicial Administration DEPARTMENT OF JUSTICE... appointment as standing trustee and fiduciary standards. (a) As used in this section— (1) The term standing... the equivalent of a spousal relationship. (3) The term financial or ownership interest excludes...

  6. Stand age and habitat influences on salamanders in Appalachian cove hardwood forests

    Science.gov (United States)

    W. Mark Ford; Brian R. Chapman; Michael A. Menzel; Richard H. Odom

    2002-01-01

    We surveyed cove hardwood stands aged 15, 25, 50, and ≥85 years following clearcutting in the southern Appalachian Mountains of northern Georgia to assess the effects of stand age and stand habitat characteristics on salamander communities using drift-fence array and pitfall methodologies from May 1994 to April 1995. Over a 60,060 pitfall trapnight effort, we...

  7. Simulation of growth and competition in mixed stands of Douglas-fir and beech

    NARCIS (Netherlands)

    Bartelink, H.H.

    1998-01-01

    For a long time, the emphasis in silviculture in Western Europe was solely on even-aged, monospecific stands; many empirical stand-level growth models were developed and successfully used for managing such stands. In contrast, no generally accepted growth and yield approach has emerged so

  8. Collection of stand data for ordination | AJ | African Journal of Range ...

    African Journals Online (AJOL)

    Four field stand tables for collecting data for the ordination of species and stands in Mopani Veld are described. The type of data and their manner of collection is indicated. It is important that data for extensive survey be collected within a reasonable time. Stand tables used should record the data in a systematic and logic ...

  9. Growth and Photosynthesis Characteristics of an Artificially Regenerated Mixed Hardwood Stand in the Southern USA

    Science.gov (United States)

    Shi-Jean S. Sung; Paul P. Kormanik; Stanley J. Zarnoch; Charles Possee

    2002-01-01

    The hardwood forests of the southern U.S. are not naturally composed of singe predominant species. The diversity of tree species within these stands is one of the qualities that make them so valuable for multiple use stand management. While many of the best hardwood sites have been planted to pines since the 1950's, some proportion of these pine stands now being...

  10. Wildland fire effects in silviculturally treated vs. untreated stands of New Mexico and Arizona

    Science.gov (United States)

    Douglas S. Cram; Terrell T. Baker; Jon C. Boren

    2006-01-01

    Stand-replacement fires, particularly in ponderosa pine (Pinus ponderosa) forests, have replaced highfrequency, low-intensity historical fire regimes. We examined whether forest stands treated recently using silvicultural practices would be (1) less susceptible to stand-replacing crownfires, and (2) more ecologically and functionally resilient...

  11. Cultural practices in Appalachian hardwood sapling stands--are they worthwhile?

    Science.gov (United States)

    Gary W. Miller

    1986-01-01

    Forest managers often question the economic feasibility of cultural practices in hardwood sapling stands. Investment factors, including initial treatment cost, required rate of return, investment period, and stand response to treatment are discussed in terms of how they affect the outcome of early investments in even-aged hardwood stands. Attention is focused on...

  12. A stand-development approach to oak afforestation in the Lower Mississippi Alluvial Valley

    Science.gov (United States)

    J. Stanturf

    2009-01-01

    Oak (Quercus spp.) afforestation in the Lower Mississippi Alluvial Valley has involved planting 1-year-old bareroot seedlings on a relatively wide spacing in single-species stands or planting light-seeded species with oaks to form mixed-species stands. In the former case, the developing single-species stands have limited future...

  13. Characteristics of the control of standing posture during pregnancy.

    Science.gov (United States)

    Nagai, Masanori; Isida, Mitsuo; Saitoh, Junko; Hirata, Yoshie; Natori, Hatsumi; Wada, Maki

    2009-09-22

    During pregnancy, the physical and mental states greatly change. We investigated the influences of pregnancy and anxiety on postural control in pregnant women (P) standing upright in the late trimester. An analysis of posturograms revealed that the area of body sway and length of antero-posterior body sway were greater in P than those in non-pregnant controls (NP). No difference was found in the medio-lateral body sway between P and NP. Fast Fourier transform analysis of body sway showed that the percentile power of the 1.0-10.0Hz band in the medio-lateral axis was smaller in P than in NP irrespective of whether the eyes were open or closed. P were divided into a high (HA) and low (LA) anxiety group on the basis of state anxiety scored by Spielberger's State- and Trait-Anxiety Inventory. A positive correlation was identified between state anxiety and the area of body sway in HA standing with eyes open. This correlation was diminished when the eyes were closed. Body sway of over 1Hz is generally stabilized by somatosensory input, therefore, the results show that body sway in the medio-lateral axis is stabilized in P by increasing the sensitivity to somatosensory cues. High anxiety during pregnancy destabilizes the standing posture when the eyes are open. The correlation between anxiety and body sway revealed by our previous studies in college students was also confirmed in P, suggesting that humans with high anxiety abstract visual cues differently from those with low anxiety.

  14. Improvement of Stand Jig Sealer and Its Increased Production Capacity

    Science.gov (United States)

    Soebandrija, K. E. N.; Astuti, S. W. D.

    2014-03-01

    This paper has the objective to prove that improvement of Stand Jig Sealer can lead to the cycle time target as part of Improvement efforts and its Productivity. Prior researches through prior journals both classics journal such as Quesnay (1766) and Solow (1957) and updated journal such as Reikard (2011) researches, are mentioned and elaborated. Precisely, the research is narrowed down and specified into automotive industry and eventually the software related of SPSS and Structural Equation Modeling ( SEM ). The analysis and its method are conducted through the calculation working time. The mentioned calculation are reinforced with the hypothesis test using SPSS Version 19 and involve parameters of production efficiency, productivity calculation, and the calculation of financial investments. The results obtained are augmented achievement of cycle time target ≤ 80 seconds posterior to improvement stand jig sealer. The result from calculation of SPSS-19 version comprise the following aspects: the one-sided hypothesis test is rejection of Ho:μ≥80 seconds, the correlation rs=0.84, regression y = 0.159+0.642x, validity R table = 0.4438, reliability value of Cronbach's alpha = 0.885>0.70, independence (Chi Square) Asymp. Sig=0.0280, PI 2.04>1, IRR 45.56%>i=12.68%, PP=1.86). The Mentioned calculation results support the hypothesis and ultimately align with the objective of this paper to prove that improvement of Stand Jig Sealer and its relation toward the cycle time target. Precisely, the improvement of production capacity of PT. Astra Daihatsu Motor.

  15. OPTIMIZATION OF HEMISPHERICAL RESONATOR GYROSCOPE STANDING WAVE PARAMETERS

    Directory of Open Access Journals (Sweden)

    Olga Sergeevna Khalyutina

    2017-01-01

    Full Text Available Traditionally, the problem of autonomous navigation is solved by dead reckoning navigation flight parameters (NFP of the aircraft (AC. With increasing requirements to accuracy of definition NFP improved the sensors of the prima- ry navigation information: gyroscopes and accelerometers. the gyroscopes of a new type, the so-called solid-state wave gyroscopes (SSVG are currently developed and put into practice. The work deals with the problem of increasing the accu- racy of measurements of angular velocity of the hemispherical resonator gyroscope (HRG. The reduction in the accuracy characteristics of HRG is caused by the presence of defects in the distribution of mass in the volume of its design. The syn- thesis of control system for optimal damping of the distortion parameters of the standing wave due to the influence of the mass defect resonator is adapted. The research challenge was: to examine and analytically offset the impact of the standing wave (amplitude and frequency parameters defect. Research was performed by mathematical modeling in the environment of SolidWorks Simulation for the case when the characteristics of the sensitive element of the HRG met the technological drawings of a particular type of resonator. The method of the inverse dynamics was chosen for synthesis. The research re- sults are presented in graphs the amplitude-frequency characteristics (AFC of the resonator output signal. Simulation was performed for the cases: the perfect distribution of weight; the presence of the mass defect; the presence of the mass defects are shown using the synthesized control action. Evaluating the effectiveness of the proposed control algorithm is deter- mined by the results of the resonator output signal simulation provided the perfect constructive and its performance in the presence of a mass defect in it. It is assumed that the excitation signals are standing waves in the two cases are identical in both amplitude and frequency. In this

  16. Standing Classrooms: Research and Lessons Learned from Around the World.

    Science.gov (United States)

    Hinckson, Erica; Salmon, Jo; Benden, Mark; Clemes, Stacey A; Sudholz, Bronwyn; Barber, Sally E; Aminian, Saeideh; Ridgers, Nicola D

    2016-07-01

    Children spend between 50 and 70 % of their time sitting while at school. Independent of physical activity levels, prolonged sitting is associated with poor health outcomes in adulthood. While there is mixed evidence of health associations among children and adolescents, public health guidelines in the USA, UK, Australia and Canada now recommend young people should break up long periods of sitting as frequently as possible. A potentially effective approach for reducing and breaking up sitting throughout the day is changing the classroom environment. This paper presents an overview of a relatively new area of research designed to reduce youth sitting time while at school by changing the classroom environment (n = 13 studies). Environmental changes included placement of height-adjustable or stand-biased standing desks/workstations with stools, chairs, exercise balls, bean bags or mats in the classroom. These 13 published studies suggest that irrespective of the approach, youth sitting time was reduced by between ~44 and 60 min/day and standing time was increased by between 18 and 55 min/day during classroom time at school. Other benefits include increased energy expenditure and the potential for improved management of students' behaviour in the classroom. However, few large trials have been conducted, and there remains little evidence regarding the impact on children's learning and academic achievement. Nevertheless, with an increasing demand placed on schools and teachers regarding students' learning outcomes, strategies that integrate moving throughout the school day and that potentially enhance the learning experience and future health outcomes for young people warrant further exploration.

  17. Asymmetry of the free-standing polyelectrolyte multilayers

    Science.gov (United States)

    Yu, Li; Yuan, Weichang; Liu, Xiaokong; Xu, Xintong; Ruan, Shuangchen

    2017-11-01

    Free-standing polyelectrolyte multilayers (PEMs) triggered an intense research effort to develop functional capsules and membranes, nevertheless, the comprehensive understanding of the surface distinctions between the two sides of the free-standing PEMs has been rarely studied. In this paper, we demonstrate the asymmetric surface morphologies, compositions, surface charge and wetting properties of the free-standing PEMs made of alternating deposition of poly(diallyldimethylammonium chloride) (PDDA) and poly(styrenesulfonate) (PSS) on uncharged trimethoxy (octyl) silane modified silicon wafer (TMOS-Si) substrates. The growth behaviors (e.g., linear or exponential growth) of the (PDDA/PSS)n PEMs deposited on TMOS-Si substrates are similar to those deposited on negatively charged substrates except a slower evolution in morphology and thickness, evidenced by atomic force microscopy (AFM) and ellipsometry. The surface charge of the two sides can be tuned as +/+, -/-, and +/- by selecting the first and the terminate layer of the polyelectrolyte during the deposition process, indicated by X-ray photoelectron spectroscopy (XPS) and the surface zeta potential measured by spinning disk method. Further, water contact angle measurements exhibit a strong difference between the back side (the bottom side that was initially contacted with the substrate) (74 ± 4°) and front side (33 ± 2° and 48 ± 3° for PDDA and PSS as the outmost layer, respectively) of the PEMs. The larger water contact angle of the back side is probably resulted from the orientation of the alkyl chains of the polyelectrolytes as the hydrophobic-hydrophobic interactions played significant roles in deposition of a polyelectrolyte onto an uncharged substrate. This paper may gain new insights on understanding surface properties of the PEMs.

  18. STANDING WAVE PROBES FOR DIMENSIONAL METROLOGY OF LOW DENSITY FOAMS

    Energy Technology Data Exchange (ETDEWEB)

    Seugling, R M; Woody, S C; Bauza, M B

    2010-03-23

    Typically, parts and geometries of interest to LLNL are made from a combination of complex geometries and a wide array of different materials ranging from metals and ceramics to low density foams and plastic foils. These parts are combined to develop physics experiments for studying material properties, equation of state (EOS) and radiation transport. Understanding the dimensional uncertainty of the parts contained within an experiment is critical to the physical understanding of the phenomena being observed and represents the motivation for developing probe metrology capability that can address LLNL's unique problems. Standing wave probes were developed for measuring high aspect ratio, micrometer scaled features with nanometer resolution. Originally conceived of for the use in the automotive industry for characterizing fuel injector bores and similar geometries, this concept was investigated and improved for use on geometries and materials important to LLNL needs within target fabrication. As part of the original project, detailed understanding of the probe dynamics and interactions with the surface of the sample was investigated. In addition, the upgraded system was utilized for measuring fuel injector bores and micro-lenses as a means of demonstrating capability. This report discusses the use of the standing wave probe for measuring features in low density foams, 55 mg/cc SiO{sub 2} and 982 mg/cc (%6 relative density) copper foam respectively. These two foam materials represent a difficult metrology challenge because of their material properties and surface topography. Traditional non-contact metrology systems such as normal incident interferometry and/or confocal microscopy have difficulty obtaining a signal from the relatively absorptive characteristics of these materials. In addition to the foam samples, a solid copper and plastic (Rexolite{trademark}) sample of similar geometry was measured with the standing wave probe as a reference for both conductive

  19. Cellular composition of long-standing gingivitis and periodontitis lesions.

    Science.gov (United States)

    Thorbert-Mros, S; Larsson, L; Berglundh, T

    2015-08-01

    Insufficient information on the cellular composition of long-standing gingivitis lesions without signs of attachment loss makes an understanding of differences in cellular composition between "destructive" and "nondestructive" periodontal lesions difficult. The aim of the current study was to analyze differences in cell characteristics between lesions representing long-standing gingivitis and severe periodontitis. Two groups of patients were recruited. One group consisted of 36 patients, 33-67 years of age, with severe generalized periodontitis (periodontitis group). The second group consisted of 28 patients, 41-70 years of age, with overt signs of gingival inflammation but no attachment loss (gingivitis group). From each patient a gingival biopsy was obtained from one selected diseased site and prepared for immunohistochemical analysis. Periodontitis lesions were twice as large and contained significantly larger proportions, numbers and densities of cells positive for CD138 (plasma cells) and CD68 (macrophages) than did gingivitis lesions. The proportion of B cells that expressed the additional CD5 marker (B-1a cells) was significantly larger in periodontitis lesions than in gingivitis lesions. The densities of T cells and B cells did not differ between periodontitis lesions and gingivitis lesions. T cells were not the dominating cell type in gingivitis lesions, as B cells together with their subset plasma cells comprised a larger number and proportion than T cells. Periodontitis lesions at teeth with advanced attachment and bone loss exhibit quantitative and qualitative differences in relation to gingivitis lesions at teeth with no attachment and bone loss. It is suggested that the large number and high density of plasma cells are the hallmarks of advanced periodontitis lesions and the most conspicuous difference in relation to long-standing gingivitis lesions. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Extraction of forest stand parameters from CARABAS VHF SAR images

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Fredrik [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Centre for Image Analysis

    1999-10-01

    Methods for extracting stand-wise forest parameters from CARABAS VHF SAR images have been developed and evaluated. CARABAS is a unique airborne synthetic aperture radar (SAR), developed by the Swedish Defence Research Establishment. It differs a lot from ordinary microwave radars by using wavelengths between 3.3 and 15 m, making the image intensity highly correlated to stem volume. Furthermore, by providing its own illumination source, the sensor operates independently of daylight and weather conditions. Empirical regression models have been developed for relating backscattering amplitude to stem volume, stem diameter, and tree height. To make comparison between CARABAS image data and forest parameters effective, a fully automatic geo-coding algorithm was developed. Image texture features have also been investigated. By using the variogram as a discriminating feature, CARABAS images and aerial images were segmented into homogeneous regions. Furthermore, a method for discriminating recently clear felled areas from forested areas, combining information from Almaz-1 SAR images and SPOT panchromatic data has also been developed, serving as a comparison to the main work of this thesis. For forest stands at near-horizontal ground, the results for estimating stem volume, stem diameter, and tree height from CARABAS image data are very satisfactory. The root mean square errors for the estimates are comparable to subjective ground-based inventories for dense forest stands. The methods and algorithms described in this thesis have been developed towards an operational remote sensing tool. Altogether, significant potential for mapping of forest characteristics exists using the CARABAS VHF SAR sensor 57 refs, 14 figs, 7 tabs

  1. Cryogenic System for the Cryomodule Test Stand at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    White, Michael J. [Fermilab; Hansen, Benjamin [Fermilab; Klebaner, Arkadiy [Fermilab

    2017-10-09

    This paper describes the cryogenic system for the Cryomodule Test Stand (CMTS) at the new Cryomodule Test Facility (CMTF) located at Fermilab. CMTS is designed for production testing of the 1.3 GHz and 3.9GHz cryomodules to be used in the Linac Coherent Light Source II (LCLSII), which is an upgrade to an existing accelerator at Stanford Linear Accelerator Laboratory (SLAC). This paper will focus on the cryogenic system that extends from the helium refrigeration plant to the CMTS cave. Topics covered will include component design, installation and commissioning progress, and operational plans. The paper will conclude with a description of the heat load measurement plan.

  2. A battery ageing model used in stand alone PV systems

    Science.gov (United States)

    Cherif, A.; Jraidi, M.; Dhouib, A.

    The authors present a new model for the ageing of a lead-acid battery which is based on the initial model of Shepherd. The proposed model allows to predict temporal variations of the Shepherd coefficients and to control the deterioration of the battery parameters and performances. The model validation has been realised by the recursive least square (RLS) algorithm by using long-term measurements under several solicitations. This study will improve the storage section of stand-alone photovoltaic systems and reduce overloads and deep discharges.

  3. Availability model of stand-alone photovoltaic system

    Science.gov (United States)

    Mazurek, G.

    2017-08-01

    In this paper we present a simple, empirical model of stand-alone photovoltaic power system availability. The model is a final result of five-year long studies and ground measurements of solar irradiation carried out in Central Europe. The obtained results facilitate sizing of PV modules that have to be installed with taking into account system's availability level in each month of a year. The model can be extended to different geographical locations, with help of local meteorological data or solar irradiation datasets derived from satellite measurements.

  4. Self-assembly of free-standing RNA membranes

    Science.gov (United States)

    Han, Daehoon; Park, Yongkuk; Kim, Hyejin; Lee, Jong Bum

    2014-07-01

    RNA has emerged as a promising material for nanostructure and microstructure engineering. Although rare, some macroscopic RNA structures have also been constructed using lipid or polymer materials. Here, we report the first example of an enzymatically generated RNA membrane. This robust and free-standing RNA membrane has a macroscopic structure and is generated without any polymer support or complexation. Our RNA membrane is fabricated following two sequential processes, complementary rolling circle transcription and evaporation-induced self-assembly, and its structural and functional properties are rationally controlled by adjusting RNA base pairing. In this study, three types of RNA membranes are fabricated and are used to demonstrate potential applications.

  5. Observations of electromagnetic radiation of stand EISCAT on Kamchatka

    Science.gov (United States)

    Sivokon, Vladimir; Agranat, Irina

    2017-10-01

    In experiments on active influence on an ionosphere powerful short-wave complexes - heater stands are used. As a result of such influence the set of the physical processes [1] which studying represents scientific interest is formed. One of them is formation artificial field-aligned irregularities. Studying properties natural field-aligned irregularities on Kamchatka [2], authors have come to a conclusion about possibility of realisation of the received approaches in their studying, on short-wave lines of the big extent. In work results of supervision on Kamchatka of displays of active influence on an ionosphere in Tromse (Norway) are resulted.

  6. Observations of electromagnetic radiation of stand EISCAT on Kamchatka

    Directory of Open Access Journals (Sweden)

    Sivokon Vladimir

    2017-01-01

    Full Text Available In experiments on active influence on an ionosphere powerful short-wave complexes – heater stands are used. As a result of such influence the set of the physical processes [1] which studying represents scientific interest is formed. One of them is formation artificial field-aligned irregularities. Studying properties natural field-aligned irregularities on Kamchatka [2], authors have come to a conclusion about possibility of realisation of the received approaches in their studying, on short-wave lines of the big extent. In work results of supervision on Kamchatka of displays of active influence on an ionosphere in Tromse (Norway are resulted.

  7. Enhanced current and voltage regulators for stand-alone applications

    DEFF Research Database (Denmark)

    Federico, de Bosio; Pastorelli, Michele; Antonio DeSouza Ribeiro, Luiz

    2016-01-01

    State feedback decoupling permits to achieve a better dynamic response for Voltage Source in stand-alone applications. The design of current and voltage regulators is performed in the discrete-time domain since it provides better accuracy and allows direct pole placement. As the attainable...... bandwidth of the current loop is mainly limited by computational and PWM delays, a lead compensator structure is proposed to overcome this limitation. The design of the voltage regulator is based on the Nyquist criterion, verifying to guarantee a high sensitivity peak. Discrete-time domain implementation...

  8. Biological productivity and nutrient distribution in artificial Michelia macclurei stand

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Z.W.; Zhang, J.W.; Chen, C.Y.; Wang, K.P.; Zhao, J.L.; Zeng, S.Y.

    1983-01-01

    M. macclurei is a valuable wood-producing species in the southern subtropical zone of China. The species has high biological productivity, the standing crop of a 16-year-old plantation and annual net production of the tree layer being respectively 202 and 27.59 t/ha. These figures are higher than those given by Cunninghamia lanceolata at the same age in its native region. Nutrient concentration (N, P, K, Ca and Mg) of the plantation varied with layer and organ, being high in the underwood and herbaceous layers, and low in the tree layer. However, absolute amounts were greatest in the tree layer. 8 references.

  9. The Cold Dark Matter Search test stand warm electronics card

    Energy Technology Data Exchange (ETDEWEB)

    Hines, Bruce; /Colorado U., Denver; Hansen, Sten; /Fermilab; Huber, Martin; /Colorado U., Denver; Kiper, Terry; /Fermilab; Rau, Wolfgang; /Queen' s U., Kingston; Saab, Tarek; /Florida U.; Seitz, Dennis; Sundqvist, Kyle; /UC, Berkeley; Mandic, Vuk; /Minnesota U.

    2010-11-01

    A card which does the signal processing for four SQUID amplifiers and two charge sensitive channels is described. The card performs the same functions as is presently done with two custom 9U x 280mm Eurocard modules, a commercial multi-channel VME digitizer, a PCI to GPIB interface, a PCI to VME interface and a custom built linear power supply. By integrating these functions onto a single card and using the power over Ethernet standard, the infrastructure requirements for instrumenting a Cold Dark Matter Search (CDMS) detector test stand are significantly reduced.

  10. Diffraction of an atomic beam by standing-wave radiation

    Science.gov (United States)

    Moskowitz, P. E.; Gould, P. L.; Atlas, S. R.; Pritchard, D. E.

    1983-08-01

    Preliminary experimental results are reported for the deflection of Na atoms in an atomic beam by a transverse standing-wave laser field whose frequency is tuned between the two ground-state hyperfine components of the D2 line. In contrast to the two experiments done previously, a splitting of the beam into two symmetric peaks whose separation increases with the electric-field is seen here. In addition, the data show evidence for atomic diffraction: a tendency for scattered atoms to acquire momentum in multiples of 2h(bar)k.

  11. Deflection of atoms by standing-wave radiation

    Science.gov (United States)

    Moskowitz, P. E.; Gould, P. L.; Pritchard, D. E.

    1985-11-01

    Momentum transfer from a standing-wave light field to an atomic beam has been observed. The atomic beam is split symmetrically into two peaks whose separation increases with field strength. The short interaction time ensures that this deflection is due to induced forces; these are described using a semiclassical dressed-atom treatment, which gives good agreement with the data. In addition to the splitting, diffraction of the atomic beam due to the exchange of even numbers of photons with the field has been observed.

  12. A measuring stand for a ducted fan aircraft propulsion unit

    Directory of Open Access Journals (Sweden)

    Hlaváček David

    2014-03-01

    Full Text Available The UL-39 ultra-light aircraft which is being developed by the Department of Aerospace Engineering, Faculty of Mechanical Engineering, Czech Technical University in Prague, is equipped with an unconventional ducted fan propulsion unit. The unit consists of an axial fan driven by a piston engine and placed inside a duct ended with a nozzle. This article describes the arrangement of a modernised measuring stand for this highly specific propulsion unit which will be able to measure the fan pressure ratio and velocity field in front of and behind the fan and its characteristic curve.

  13. Do sit-to-stand performance changes during gait acquisition?

    OpenAIRE

    Bastos, Alana Maria Ferreira Guimarães; Costa, Carolina Souza Neves da; Rocha, Nelci Adriana Cicuto Ferreira

    2014-01-01

    In a child's daily routine, sit-to-stand (STS) is a prerequisite activity for many functional tasks. The relationship between gait and other abilities has been pointed out by many authors, but there is no study investigating the changes in STS during gait acquisition in children. The purpose of this study was to analyse, in healthy children, changes that occur in STS performance during gait acquisition. Five healthy children were initially assessed with an average age of 13.6 months. The kine...

  14. Benchmarking the Collocation Stand-Alone Library and Toolkit (CSALT)

    Science.gov (United States)

    Hughes, Steven; Knittel, Jeremy; Shoan, Wendy; Kim, Youngkwang; Conway, Claire; Conway, Darrel J.

    2017-01-01

    This paper describes the processes and results of Verification and Validation (VV) efforts for the Collocation Stand Alone Library and Toolkit (CSALT). We describe the test program and environments, the tools used for independent test data, and comparison results. The VV effort employs classical problems with known analytic solutions, solutions from other available software tools, and comparisons to benchmarking data available in the public literature. Presenting all test results are beyond the scope of a single paper. Here we present high-level test results for a broad range of problems, and detailed comparisons for selected problems.

  15. Natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China.

    Directory of Open Access Journals (Sweden)

    Xitian Yang

    Full Text Available Natural regeneration is the natural process by which plants replace themselves. It is a cost-effective way to re-establish vegetation, and it helps to preserve genetic identity and diversity. In this study, we investigated the natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China, which were dominated by Robinia pseudoacacia (black locust, Quercus variabilis (Chinese cork oak and Platycladus orientalis (Chinese arborvitae respectively. A consistent pattern was found among the three types of stands, being that the density of seedlings was positively correlated with the overstory canopy cover and negatively correlated with the covers of shrub, herb and litter layers. While a positive correlation between the density of seedlings and stand age was found for the conifer stands, negative correlations were found for the two types of broadleaf stands. Correlations between the density of saplings and the stand attributes were not consistent among the three types of stands. The two types of broadleaf stands had higher densities of seedlings and saplings than the conifer stands. While the broadleaf stands had adequate recruits for regeneration, the conifer stands did not have enough recruits. Our findings suggest that the overstory canopy should be prevented from being disturbed, any reduction of the canopy cover will decrease the recruits and affect the regeneration.

  16. The effect of standing interventions on acute low-back postures and muscle activation patterns.

    Science.gov (United States)

    Fewster, Kayla M; Gallagher, Kaitlin M; Callaghan, Jack P

    2017-01-01

    Occupations requiring prolonged periods of constrained standing are associated with the development of low back pain (LBP). Many workplaces use improvised standing aids aimed to reduce LBP. Unfortunately, there is little scientific evidence to support the use of such standing interventions in effectively reducing LBP. To assess some commonly implemented standing interventions, thirty-one participants stood in four different standing positions (Level Ground (control), Sloped, Elevated, and Staggered) for 5 min each. The use of an elevated surface changed the lumbar spine posture of participants such that participants stood in a more flexed lumbar spine posture. This change in lumbar spine posture may be an indication that the elevated standing aid intervention can positively impact lumbar spine posture in standing pain developers and potentially reduce LBP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Using LiDAR Metrics to Characterize Forest Structural Complexity at Multiple Scales

    Science.gov (United States)

    Kane, V. R.; McGaughey, R. J.; Gersonde, R.; Franklin, J. F.

    2007-12-01

    Forest structure - the size and arrangement of trees and foliage - reflects a stand's history of initiation, growth, disturbance, and mortality. Because of this, studying the structure of forests can provide key insights into ecological processes, guides to silvicultural prescriptions to improve habitat, and assessments of forested landscapes. This study tested LiDAR metrics to characterize stands based on canopy structure. The study site was the 34,591 ha of forests in the Cedar River Watershed in western Washington State, USA. Stands ranged in age from 350 years old (including old-growth). Study sites spanned the western hemlock- Douglas fir (Tsuga heterophylla-Pseudotsuga menziesii), Pacific silver fir (Abies amabilis), and mountain hemlock (Tsuga mertansiana) forest zones. Eighty sample plots were used to ground truth the LiDAR data. A variety of structural indices were used to study canopy structural variations at the plot, stand, and landscape scales. The two most successful indices used the exposed geometry of the canopy surface: (1) the ratio of the canopy surface area to ground surface area (rumple index), and (2) the ratio of the volume beneath the canopy surface to maximum volume beneath the 95th percentile height (modified canopy volume method). These two indices integrated the spatial effects of tree heights, foliage distribution, and tree arrangement within 15m pixels. Variation between pixels revealed structural complexity at larger scales. Results: At the plot scale (~4 pixels), correlations with standard plot metrics (e.g., diameter at breast height) were similar to those reported by other studies. Comparison of structural complexity with age and height revealed a diversity of development pathways. The relationship between height and complexity allowed stands to be classified by the degree to which they have achieved their potential structural complexity, a new way to examine forest development. At the stand scale, the indices allowed spatial

  18. Impact of Acoustic Standing Waves on Structural Responses

    Science.gov (United States)

    Kolaini, Ali R.

    2014-01-01

    For several decades large reverberant chambers and most recently direct field acoustic testing have been used in the aerospace industry to test larger structures with low surface densities such as solar arrays and reflectors to qualify them and to detect faults in the design and fabrication. It has been reported that in reverberant chamber and direct acoustic testing, standing acoustic modes may strongly couple with the fundamental structural modes of the test hardware (Reference 1). In this paper results from a recent reverberant chamber acoustic test of a composite reflector are discussed. These results provide further convincing evidence of the acoustic standing wave and structural modes coupling phenomenon. The purpose of this paper is to alert test organizations to this phenomenon so that they can account for the potential increase in structural responses and ensure that flight hardware undergoes safe testing. An understanding of the coupling phenomenon may also help minimize the over and/or under testing that could pose un-anticipated structural and flight qualification issues.

  19. Multimode laser emission from free-standing cylindrical microcavities

    Energy Technology Data Exchange (ETDEWEB)

    Peter, Jaison, E-mail: jaisonpeter@cusat.ac.in; Radhakrishnan, P.; Nampoori, V.P.N.; Kailasnath, M.

    2014-05-01

    We report a well resolved whispering gallery mode (WGM) laser emission from a free-standing microring cavity based on a dye doped hollow polymer optical fiber (DDHPOF), which is transversely pumped by a pulsed Nd:YAG laser. The microring laser is characterized by a well-defined, low threshold pump power at which the emission spectral intensity dramatically increases and collapses into several dominant microcavity laser modes with reduced mode spacing and high Q-value. Resonant modes are excited inside the gain medium which is strongly confined along the radial direction so that the spacing of lasing modes is controlled by the diameter of the cylindrical microcavity. A variation in the free spectral range of WGM spectra from 0.23 to 0.09 nm coupled with a red-shift is observed with an increase in the diameter of DDHPOFs. - Highlights: • Different diameter free-standing cylindrical microcavity lasers have been fabricated and their performances have been evaluated. • The microring laser is characterized by a well-defined, low threshold pump power, with reduced mode spacing and high Q-value. • When the diameter of DDHPOF increases, the number of lasing peaks increases along with the decrease of the FSR as observed from our studies. • It is also found that whispering gallery lasing envelope is shifted from 559 to 571 nm (Stokes shift) with the diameter.

  20. Phase plane analysis of stability in quiet standing.

    Science.gov (United States)

    Riley, P O; Benda, B J; Gill-Body, K M; Krebs, D E

    1995-10-01

    We analyzed the standing balance control of 11 healthy subjects and 15 subjects with bilateral vestibular hypofunction (BVH) using phase plane (velocity versus displacement) plots. We hypothesized that maintaining postural stability requires control of both the position and momentum of the center of gravity (CG) and infer that it is advantageous to use both velocity and displacement data to characterize balance control. Phase plane plots provide insight into this dynamic aspect of balance control. We evaluated phase plane plots based on whole body CG and center of pressure (CoP). We varied stability by altering the base of support and visual information. Three different foot placements were used: feet wide apart, feet together, and semitandem stance. Feet together standing was performed with eyes open and with eyes closed. The phase plane plots show changes in stability as base of support is altered or visual input is removed and reveal stability differences between the control and BVH groups. The root mean square variance of velocity and displacement was used to quantify the phase plane information. This parameter showed significant differences between activities and between groups. We conclude that phase plane plots that combine displacement and velocity information are more useful in characterizing balance control than displacement or velocity alone.