WorldWideScience

Sample records for ground cover density

  1. Georadar Measurements for the Snow Cover Density

    Directory of Open Access Journals (Sweden)

    A. Godio

    2009-01-01

    Full Text Available Ground Probing Radar (GPR devices is adopted for the analysis of thickness and the mechanical properties (density of the snow cover in some test site in Alps, in Northern Italy. The performances of standard radar systems for the snow cover characterisation are analysed, the main aim is to assess the reliability of the method to estimate the snow density, the snowpack thickness and the depth resolution in terms of capability to detect thin layers. The main relationships between the electrical permittivity and the density of the dry-snow are applied to estimate the density vertical profiles inferred by the GPR investigation. The data were calibrated and compared with the results coming from direct measurements of the density and thickness.

  2. Interannual changes in snow cover and its impact on ground surface temperatures in Livingston Island (Antarctica)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2015-04-01

    , which prevents cooling. Reina Sofia shows a very different behavior from the other sites, with a frequent stabilization of ground temperatures during all the winters, and last until late-fall. This situation could be related to the structure, and physical and thermal properties of snow cover. The analysis of the Freezing Degree Days (FDDs) and freezing n-factor reveals significant interannual variations. Ohridski shows the highest FDDs values followed by Reina Sofia. Nuevo Incinerador showed the lowest FDDs values. The freezing n-factor shows highest values at Ohridski, followed by Collado Ramos and Reina Sofia with very similar values. Nuevo Incinerador shows the lowest n-factor values. Snow cover doesn't insulate the ground from freezing, but depending on its thickness, density and the amount of heat in the ground, it decreases ground temperatures amplitudes and increases delays relative to air temperature changes. Even where snow cover remains several centimeters thick for several months, slow decrease of bottom temperature is possible, reaching a minimum value at the end of the winter. The results demonstrate that Reina Sofia and Ohridski sites, because of the seasonal behavior, FDDs and freezing n-factor, demonstrate higher winter ground cooling. This research was funded by PERMANTAR-3 (PTDC/AAG-GLO/3908/2012) project (Fundação para a Ciência e a Tecnologia of Portugal)

  3. Ground-state densities from the Rayleigh-Ritz variation principle and from density-functional theory.

    Science.gov (United States)

    Kvaal, Simen; Helgaker, Trygve

    2015-11-14

    The relationship between the densities of ground-state wave functions (i.e., the minimizers of the Rayleigh-Ritz variation principle) and the ground-state densities in density-functional theory (i.e., the minimizers of the Hohenberg-Kohn variation principle) is studied within the framework of convex conjugation, in a generic setting covering molecular systems, solid-state systems, and more. Having introduced admissible density functionals as functionals that produce the exact ground-state energy for a given external potential by minimizing over densities in the Hohenberg-Kohn variation principle, necessary and sufficient conditions on such functionals are established to ensure that the Rayleigh-Ritz ground-state densities and the Hohenberg-Kohn ground-state densities are identical. We apply the results to molecular systems in the Born-Oppenheimer approximation. For any given potential v ∈ L(3/2)(ℝ(3)) + L(∞)(ℝ(3)), we establish a one-to-one correspondence between the mixed ground-state densities of the Rayleigh-Ritz variation principle and the mixed ground-state densities of the Hohenberg-Kohn variation principle when the Lieb density-matrix constrained-search universal density functional is taken as the admissible functional. A similar one-to-one correspondence is established between the pure ground-state densities of the Rayleigh-Ritz variation principle and the pure ground-state densities obtained using the Hohenberg-Kohn variation principle with the Levy-Lieb pure-state constrained-search functional. In other words, all physical ground-state densities (pure or mixed) are recovered with these functionals and no false densities (i.e., minimizing densities that are not physical) exist. The importance of topology (i.e., choice of Banach space of densities and potentials) is emphasized and illustrated. The relevance of these results for current-density-functional theory is examined.

  4. Ground state of high-density matter

    Science.gov (United States)

    Copeland, ED; Kolb, Edward W.; Lee, Kimyeong

    1988-01-01

    It is shown that if an upper bound to the false vacuum energy of the electroweak Higgs potential is satisfied, the true ground state of high-density matter is not nuclear matter, or even strange-quark matter, but rather a non-topological soliton where the electroweak symmetry is exact and the fermions are massless. This possibility is examined in the standard SU(3) sub C tensor product SU(2) sub L tensor product U(1) sub Y model. The bound to the false vacuum energy is satisfied only for a narrow range of the Higgs boson masses in the minimal electroweak model (within about 10 eV of its minimum allowed value of 6.6 GeV) and a somewhat wider range for electroweak models with a non-minimal Higgs sector.

  5. Estimating ground water recharge from topography, hydrogeology, and land cover.

    Science.gov (United States)

    Cherkauer, Douglas S; Ansari, Sajjad A

    2005-01-01

    Proper management of ground water resources requires knowledge of the rates and spatial distribution of recharge to aquifers. This information is needed at scales ranging from that of individual communities to regional. This paper presents a methodology to calculate recharge from readily available ground surface information without long-term monitoring. The method is viewed as providing a reasonable, but conservative, first approximation of recharge, which can then be fine-tuned with other methods as time permits. Stream baseflow was measured as a surrogate for recharge in small watersheds in southeastern Wisconsin. It is equated to recharge (R) and then normalized to observed annual precipitation (P). Regression analysis was constrained by requiring that the independent and dependent variables be dimensionally consistent. It shows that R/P is controlled by three dimensionless ratios: (1) infiltrating to overland water flux, (2) vertical to lateral distance water must travel, and (3) percentage of land cover in the natural state. The individual watershed properties that comprise these ratios are now commonly available in GIS data bases. The empirical relationship for predicting R/P developed for the study watersheds is shown to be statistically viable and is then tested outside the study area and against other methods of calculating recharge. The method produces values that agree with baseflow separation from streamflow hydrographs (to within 15% to 20%), ground water budget analysis (4%), well hydrograph analysis (12%), and a distributed-parameter watershed model calibrated to total streamflow (18%). It has also reproduced the temporal variation over 5 yr observed at a well site with an average error < 12%.

  6. Database for estimating tree responses of walnut and other hardwoods to ground cover management practices

    Science.gov (United States)

    J.W. Van Sambeek

    2010-01-01

    The ground cover in plantings of walnut and other hardwoods can substantially affect tree growth and seed production. The number of alternative ground covers that have been suggested for establishment in tree plantings far exceeds the number that have already been tested with walnut and other temperate hardwoods. Knowing how other hardwood species respond to ground...

  7. Predicting above-ground density and distribution of small mammal prey species at large spatial scales.

    Science.gov (United States)

    Olson, Lucretia E; Squires, John R; Oakleaf, Robert J; Wallace, Zachary P; Kennedy, Patricia L

    2017-01-01

    Grassland and shrub-steppe ecosystems are increasingly threatened by anthropogenic activities. Loss of native habitats may negatively impact important small mammal prey species. Little information, however, is available on the impact of habitat variability on density of small mammal prey species at broad spatial scales. We examined the relationship between small mammal density and remotely-sensed environmental covariates in shrub-steppe and grassland ecosystems in Wyoming, USA. We sampled four sciurid and leporid species groups using line transect methods, and used hierarchical distance-sampling to model density in response to variation in vegetation, climate, topographic, and anthropogenic variables, while accounting for variation in detection probability. We created spatial predictions of each species' density and distribution. Sciurid and leporid species exhibited mixed responses to vegetation, such that changes to native habitat will likely affect prey species differently. Density of white-tailed prairie dogs (Cynomys leucurus), Wyoming ground squirrels (Urocitellus elegans), and leporids correlated negatively with proportion of shrub or sagebrush cover and positively with herbaceous cover or bare ground, whereas least chipmunks showed a positive correlation with shrub cover and a negative correlation with herbaceous cover. Spatial predictions from our models provide a landscape-scale metric of above-ground prey density, which will facilitate the development of conservation plans for these taxa and their predators at spatial scales relevant to management.

  8. [Diversity and stability of arthropod community in peach orchard under effects of ground cover vegetation].

    Science.gov (United States)

    Jiang, Jie-xian; Wan, Nian-feng; Ji, Xiang-yun; Dan, Jia-gui

    2011-09-01

    A comparative study was conducted on the arthropod community in peach orchards with and without ground cover vegetation. In the orchard with ground cover vegetation, the individuals of beneficial, neutral, and phytophagous arthropods were 1.48, 1.84 and 0.64 times of those in the orchard without ground cover vegetation, respectively, but the total number of arthropods had no significant difference with that in the orchard without ground cover vegetation. The species richness, Shannon's diversity, and Pielou's evenness index of the arthropods in the orchard with ground cover vegetation were 83.733 +/- 4.932, 4.966 +/- 0.110, and 0.795 +/- 0.014, respectively, being significantly higher than those in the orchard without ground cover vegetation, whereas the Berger-Parker's dominance index was 0.135 +/- 0.012, being significantly lower than that (0.184 +/- 0.018) in the orchard without ground cover vegetation. There were no significant differences in the stability indices S/N and Sd/Sp between the two orchards, but the Nn/Np, Nd/Np, and Sn/Sp in the orchard with ground cover vegetation were 0.883 +/- 0.123. 1714 +/- 0.683, and 0.781 +/- 0.040, respectively, being significantly higher than those in the orchard without ground cover vegetation. Pearson's correlation analysis indicated that in the orchard with ground cover vegetation, the Shannon's diversity index was significantly negatively correlated with Nd/Np, Sd/Sp, and S/N but had no significant correlations with Nn/Np and Sn/Sp, whereas in the orchard without ground cover vegetation, the diversity index was significantly positively correlated with Nn/Np and Nd/Np and had no significant correlations with Sd/Sp, Sn/Sp, and S/N.

  9. Accurate Quantification of Grassland Cover Density in an Alpine Meadow Soil Based on Remote Sensing and GPS

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-Sui; HU Ye-Cui; PENG Liu-Ying

    2005-01-01

    The principles of remotely estimating grassland cover density in an alpine meadow soil from space lie in the synchronous collection of in situ samples with the satellite pass and statistically linking these cover densities to their image properties according to their geographic coordinates. The principles and procedures for quantifying grassland cover density from satellite image data were presented with an example from Qinghai Lake, China demonstrating how quantification could be made more accurate through the integrated use of remote sensing and global positioning systems (GPS). An empirical model was applied to an entire satellite image to convert pixel values into ground cover density. Satellite data based on 68 field samples was used to produce a map of ten cover densities. After calibration a strong linear regression relationship (r2 = 0.745) between pixel values on the satellite image and in situ measured grassland cover density was established with an 89% accuracy level. However, to minimize positional uncertainty of field samples, integrated use of hyperspatial satellite data and GPS could be utilized. This integration could reduce disparity in ground and space sampling intervals,and improve future quantification accuracy even more.

  10. Legume ground covers alter defoliation response of black walnut saplings to drought and anthracnose

    Science.gov (United States)

    J. W. Van Sambeek

    2003-01-01

    Growth and premature defoliation of black walnut saplings underplanted 5 or 6 years earlier with six different ground covers were quantified in response to a summer drought or anthracnose. Walnut saplings growing with ground covers of hairy vetch, crownvetch, and to a lesser extent sericea lespedeza continued to have more rapid height and diameter growth than saplings...

  11. Law school design blends functionalism, energy conservation. [Earth-covered with ground-cover growing on roof

    Energy Technology Data Exchange (ETDEWEB)

    1976-08-01

    Construction is under way on a new University of Minnesota Law School Building, whose distinctive features include a stepped design on its southern elevation and an earth-covered roof to promote energy conservation. The design is described with emphasis on the library facilities. Energy conservation was a major design factor. The portion of the earth-covered roof will be 15 inches thick planted with low ground-cover vegetation. Overall ..mu.. value of the building envelope will be 0.11. (MCW)

  12. Fast ground filtering for TLS data via Scanline Density Analysis

    Science.gov (United States)

    Che, Erzhuo; Olsen, Michael J.

    2017-07-01

    Terrestrial Laser Scanning (TLS) efficiently collects 3D information based on lidar (light detection and ranging) technology. TLS has been widely used in topographic mapping, engineering surveying, forestry, industrial facilities, cultural heritage, and so on. Ground filtering is a common procedure in lidar data processing, which separates the point cloud data into ground points and non-ground points. Effective ground filtering is helpful for subsequent procedures such as segmentation, classification, and modeling. Numerous ground filtering algorithms have been developed for Airborne Laser Scanning (ALS) data. However, many of these are error prone in application to TLS data because of its different angle of view and highly variable resolution. Further, many ground filtering techniques are limited in application within challenging topography and experience difficulty coping with some objects such as short vegetation, steep slopes, and so forth. Lastly, due to the large size of point cloud data, operations such as data traversing, multiple iterations, and neighbor searching significantly affect the computation efficiency. In order to overcome these challenges, we present an efficient ground filtering method for TLS data via a Scanline Density Analysis, which is very fast because it exploits the grid structure storing TLS data. The process first separates the ground candidates, density features, and unidentified points based on an analysis of point density within each scanline. Second, a region growth using the scan pattern is performed to cluster the ground candidates and further refine the ground points (clusters). In the experiment, the effectiveness, parameter robustness, and efficiency of the proposed method is demonstrated with datasets collected from an urban scene and a natural scene, respectively.

  13. DTM generation using land cover classification based on low density lidar data

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    Koma, Zsófia; Zlinszky, András

    2014-05-01

    While the point density of local LIDAR surveys continues to increase, most regional or national LIDAR campaigns are carried out with medium or low density, and have the main purpose of DTM generation. Many different point selection and filtering algorithms are already established. Depending on land cover and vegetation, some perform better than others, but no algorithm exists that works perfectly for all types of land cover. Therefore, our method applies several different DTM generation and filtering algorithms for different spatial units depending on their land cover and vegetation. Land cover and vegetation are mapped based on the original raw LIDAR dataset. Two discrete echo airborne LIDAR measurements were used, one with 1 point/m2 and a larger area with 0.4 point/m2 density. The datasets were used together for DTM generation after relative georeferencing by strip adjustment. We defined several land cover categories depending on how they influence vertical distribution of LIDAR points: buildings, waterways, grasslands, crop fields, wetlands, and forests. The study area was classified to these categories based on a decision tree algorithm using parameters calculated from the original LIDAR dataset (sigmaZ, reflectance, aspect, slope, echoratio, roughness), at resolution identical to the output DTM. For the points within spatial units belonging to each of these categories, we implemented different filtering and interpolation methods to select ground points. For buildings, roof and wall points were removed and the resulting gap filled by interpolated based on the neighbouring data. In forests we calculated a first smooth approximate surface based on minimum points every 10 meter cells. We calculated a residual value for every point of this surface in this class. Then we analysed the point cloud based on residuals value and made an optimum threshold which classified the datasets for non-ground and ground points. In wetlands and croplands, the point height range

  14. Diseases of Ornamental and Shade Trees, Shrubs, Vines, and Ground Covers.

    Science.gov (United States)

    Nichols, Lester P.

    This agriculture extension service publication from Pennsylvania State University covers the identification and control of common ornamental trees, shrubs, and ground cover diseases. The publication is divided into sections. The first section discusses the diseases of ornamental and shade trees, including general diseases and diseases of specific…

  15. Effects of ground cover from branches of arboreal species on weed growth and maize yield

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    Full Text Available ABSTRACTCultivating maize under systems of alley cropping results in improvements to the soil, a reduction in weeds and an increase in yield. Studies using ground cover from tree shoots produce similar results. The aim of this study was to evaluate the effects on weed growth and maize yield of ground cover made up of 30 t ha-1 (fresh matter of branches from the tree species: neem (Azadirachta indica A. Juss, gliricidia [Gliricidia sepium(Jacq. Kunth ex Walp.], leucaena [Leucaena leucocephala (Lam. de Wit.] and sabiá (Mimosa caesalpiniifolia Benth.. Two treatment groups (cultivars and weed control were evaluated. The cultivars AG 1041 and AL Bandeirantes were subjected to the following treatments: no hoeing, double hoeing, and ground a cover of branches of the above species when sowing the maize. A randomised block design was used with split lots (cultivars in the lots and ten replications. The cultivars did not differ for green ear or grain yield. Double hoeing was more effective than ground cover at reducing the growth of weeds. However, both weeding and ground cover resulted in similar yields for green ears and grain, which were greater than those obtained with the unweeded maize.

  16. Experimental evaluation of ALS point cloud ground extraction over different land cover in the Malopolska Province

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    Korzeniowska, Karolina; Mandlburger, Gottfried; Klimczyk, Agata

    2013-04-01

    The paper presents an evaluation of different terrain point extraction algorithms for Airborne Laser Scanning (ALS) point clouds. The research area covers eight test sites in the Małopolska Province (Poland) with varying point density between 3-15points/m² and surface as well as land cover characteristics. In this paper the existing implementations of algorithms were considered. Approaches based on mathematical morphology, progressive densification, robust surface interpolation and segmentation were compared. From the group of morphological filters, the Progressive Morphological Filter (PMF) proposed by Zhang K. et al. (2003) in LIS software was evaluated. From the progressive densification filter methods developed by Axelsson P. (2000) the Martin Isenburg's implementation in LAStools software (LAStools, 2012) was chosen. The third group of methods are surface-based filters. In this study, we used the hierarchic robust interpolation approach by Kraus K., Pfeifer N. (1998) as implemented in SCOP++ (Trimble, 2012). The fourth group of methods works on segmentation. From this filtering concept the segmentation algorithm available in LIS was tested (Wichmann V., 2012). The main aim in executing the automatic classification for ground extraction was operating in default mode or with default parameters which were selected by the developers of the algorithms. It was assumed that the default settings were equivalent to the parameters on which the best results can be achieved. In case it was not possible to apply an algorithm in default mode, a combination of the available and most crucial parameters for ground extraction were selected. As a result of these analyses, several output LAS files with different ground classification were achieved. The results were described on the basis of qualitative and quantitative analyses, both being in a formal description. The classification differences were verified on point cloud data. Qualitative verification of ground extraction was

  17. Ground cover rice production system facilitates soil carbon and nitrogen stocks at regional scale

    Directory of Open Access Journals (Sweden)

    M. Liu

    2015-02-01

    Full Text Available Rice production is increasingly challenged by irrigation water scarcity, however covering paddy rice soils with films (ground cover rice production system: GCRPS can significantly reduce water demand as well as overcome temperature limitations at the beginning of the vegetation period resulting in increased grain yields in colder regions of rice production with seasonal water shortages. It has been speculated that the increased soil aeration and temperature under GCRPS may result in losses of soil organic carbon and nitrogen stocks. Here we report on a regional scale experiment, conducted by sampling paired adjacent Paddy and GCRPS fields at 49 representative sites in the Shiyan region, which is typical for many mountainous areas across China. Parameters evaluated included soil C and N stocks, soil physical and chemical properties, potential carbon mineralization rates, fractions of soil organic carbon and stable carbon isotopic composition of plant leaves. Furthermore, root biomass was quantified at maximum tillering stage at one of our paired sites. Against expectations the study showed that: (1 GCRPS significantly increased soil organic C and N stocks 5–20 years following conversion of production systems, (2 there were no differences between GCRPS and Paddy in soil physical and chemical properties for the various soil depths with the exception of soil bulk density, (3 GCRPS had lower mineralization potential for soil organic C compared with Paddy over the incubation period, (4 GCRPS showed lower δ15N in the soils and plant leafs indicating less NH3 volatilization in GCRPS than in Paddy; and (5 GCRPS increased yields and root biomass in all soil layers down to 40 cm depth. Our results suggest that GCRPS is an innovative rice production technique that not only increases yields using less irrigation water, but that it also is environmentally beneficial due to increased soil C and N stocks at regional scale.

  18. Estimation of snow cover distribution in Beas basin, Indian Himalaya using satellite data and ground measurements

    Indian Academy of Sciences (India)

    H S Negi; A V Kulkarni; B S Semwal

    2009-10-01

    In the present paper,a methodology has been developed for the mapping of snow cover in Beas basin,Indian Himalaya using AWiFS (IRS-P6)satellite data.The complexities in the mapping of snow cover in the study area are snow under vegetation,contaminated snow and patchy snow. To overcome these problems,field measurements using spectroradiometer were carried out and reflectance/snow indices trend were studied.By evaluation and validation of different topographic correction models,it was observed that,the normalized difference snow index (NDSI)values remain constant with the variations in slope and aspect and thus NDSI can take care of topography effects.Different snow cover mapping methods using snow indices are compared to find the suitable mapping technique.The proposed methodology for snow cover mapping uses the NDSI (estimated using planetary re flectance),NIR band reflectance and forest/vegetation cover information.The satellite estimated snow or non-snow pixel information using proposed methodology was validated with the snow cover information collected at three observatory locations and it was found that the algorithm classify all the sample points correctly,once that pixel is cloud free.The snow cover distribution was estimated using one year (2004 –05)cloud free satellite data and good correlation was observed between increase/decrease areal extent of seasonal snow cover and ground observed fresh snowfall and standing snow data.

  19. Fractional Vegetation Cover of East African Wetlands Observed on Ground and from Space

    Science.gov (United States)

    Schmidt, M.; Amler, E.; Guerschmann, J. P.; Scarth, P.; Behn, K.; Thonfeld, F.

    2016-08-01

    Wetlands are important ecosystems providing numerous ecosystem services. They are of particular importance to communities in East Africa where agriculture is the most important economic sector and where food availability to households critical. During an intensive field campaign in the dry season of 2013 were Fractional Vegetation Cover (FVC) measurements, botanical vegetation cover and vegetation structure estimates acquired in three wetland test sites within the East African region. FVC cover data were collated in three strata: ground layer, midstorey and overstorey (woody vegetation greater than 2 m). Fractional cover estimates for the green and no-green vegetative fraction were calculated for Landsat MODIS imagery. These FVC data products were evaluated a) with FVC field data and b) relative to each other for their usability in the East African region. First results show some promise for further studies.

  20. Ground cover influence on evaporation and stable water isotopes in soil water

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    Magdalena Warter, Maria; Jiménez-Rodríguez, Cesar D.; Coenders-Gerrits, Miriam; Teuling, Adriaan J. Ryan

    2017-04-01

    Forest ecosystems are characterized by complex structures which influence hydrological processes such as evaporation. The vertical stratification of the forest modifies the effect of the evaporation process due to the composition and local distribution of species within the forest. The evaluation of it will improve the understanding of evaporation in forest ecosystems. To determine the influence of forest understory on the fractionation front, four ground cover types were selected from the Speulderbos forest in the Netherlands. The native species of Thamariskmoss (Thuidium thamariscinum), Rough Stalked Feathermoss (Brachythecium rutabulum), and Haircapmoss (Polytrichum commune) as well as one type of litter made up of Douglas-Fir needles (Pseudotsuga menziesii) were used to analyse the rate of evaporation and changes on the isotopic concentration of the soil water on an in-situ basis in a controlled environment. Over a period of 4 weeks soil water content and atmospheric conditions were continuously measured, while the rainfall simulations were performed with different amounts and timings. The reference water added to the boxes keeps a stable composition along the trial period with a δ ^2H value of -42.59±1.15 \\permil} and δ 18O of -6.01±0.21 \\permil}. The evaporation front in the four ground covers is located between 5 and 10 cm depth and deuterium excess values are bigger than 5 \\permil. The litter layer of Douglas-Fir needles is the cover with higher fractionation in respect to the added water at 10 cm depth (δ ^2H: -29.79 \\permil), while the Haircapmoss keeps the lower fractionation rate at 5 cm and 10 cm (δ ^2H: -33.62 and δ ^2H: -35.34 \\permil). The differences showed by the soil water beneath the different ground covers depict the influence of ground cover on fractionation rates of the soil water, underlining the importance of the spatial heterogeneity of the evaporation front in the first 15 cm of soil.

  1. Assessing post-fire ground cover in Mediterranean shrublands with field spectrometry and digital photography

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    Montorio Llovería, Raquel; Pérez-Cabello, Fernando; García-Martín, Alberto

    2016-09-01

    Fire severity can be assessed by identifying and quantifying the fractional abundance of post-fire ground cover types, an approach with great capacity to predict ecosystem response. Focused on shrubland formations of Mediterranean-type ecosystems, three burned areas (Ibieca and Zuera wildfires and Peñaflor experimental fire) were sampled in the summers of 2006 and 2007. Two different ground measurements were made for each of the 356 plots: (i) 3-band high spatial resolution photography (HSRP) and (ii) the hemispherical-conical reflectance factor (HCRF) in the visible to near-infrared spectral range (VNIR, 400-900 nm). Stepwise multiple lineal regression (SMLR) models were fitted to spectral variables (HCRF, first derivative spectra or FDS, and four absorption indices) to estimate the fractional cover of seven post-fire ground cover types (vegetation and soil - unburned and charred components - and ash - char and ash, individually and as a combined category). Models were developed and validated at the Peñaflor site (training, n = 217; validation, n = 88) and applied to the samples from the Ibieca and Zuera sites (n = 51). The best results were observed for the abundance estimations of green vegetation (Radj.20.70-0.90), unburned soil (Radj.20.40-0.75), and the combination of ashes (Radj.20.65-0.80). In comparison of spectral data, FDS outperforms reflectance or absorption data because of its higher accuracy levels and, importantly, its greater capacity to yield generalizable models. Future efforts should be made to improve the estimation of intermediate severity levels and upscaling the developed models. In the context of fire severity assessment, our study demonstrates the potential of hyperspectral data to estimate in a quick and objective manner post-fire ground cover fractions and thus provide valuable information to guide management responses.

  2. Land cover for Ukraine: the harmonization of remote sensing and ground-based data

    Science.gov (United States)

    Lesiv, M.; Shchepashchenko, D.; Shvidenko, A.; See, L. M.; Bun, R.

    2012-12-01

    This study focuses on the development of a land cover map of the Ukraine through harmonization of remote sensing and ground-based data. At present there is no land cover map of the Ukraine available that is of sufficient accuracy for use in environmental modeling. The existing remote sensing data are not enough accurate. In this study we compare the territory of the Ukraine from three global remote sensing products (GlobCover 2009, MODIS Land Cover and GLC-2000) using a fuzzy logic methodology in order to capture the uncertainty in the classification of land cover. The results for the Ukraine show that GlobCover 2009, MODIS Land Cover and GLC-2000 have a fuzzy agreement of 65%. We developed a weighted algorithm for the creation of a land cover map based on an integration of a number of global land cover and remote sensing products including the GLC-2000, GlobCover 2009, MODIS Land Cover, the Vegetation Continuous Fields product, digital map of administrative units and forest account data at the local level. This weighted algorithm is based on the results of comparing these products and an analysis of a dataset of validation points for different land cover types in the Ukraine. We applied this algorithm to generate a forest land cover type map. This raster map contains a forest expectation index that was calculated for each pixel. Forest land was then allocated based on forest statistics at the local level. Areas with a higher forest expectation index were allocated with forest first until the results matched the forest statistics. The result is the first digital map of forest (with a spatial resolution of 300m) for the Ukraine, which consistent with forest and land accounts, remote sensing datasets and GIS products. The forest land was well defined in forest rich areas (i.e. in the northern part of the Ukraine, the Carpathians and the Crimea); well less accurate areas were identified in the steppe due to heterogeneous land cover. Acknowledgements. This research was

  3. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    Directory of Open Access Journals (Sweden)

    Daniel Paredes

    Full Text Available Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history, the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard, or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae in 2,528 olive groves in Andalusia (Spain from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  4. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    Science.gov (United States)

    Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M; Campos, Mercedes

    2015-01-01

    Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history), the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard), or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae) in 2,528 olive groves in Andalusia (Spain) from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  5. Covering of heating load of object by using ground heat as a renewable energy source

    Directory of Open Access Journals (Sweden)

    Čenejac Aleksandra R.

    2012-01-01

    Full Text Available Rational use of energy, improving energy performance of buildings and use of renewable energy sources are the most important measures for reducing consumption of non-renewable primary energy (solid, liquid, and gaseous fuels, environmental protection and for the future sustainable development of mankind. In the total primary energy consumption great part is related to building industry, for heating spaces in which people stay and live. Renewable energy sources (RES present natural resources and they are one of the alternatives that allow obtaining heat for heating buildings, and by that they provide a significant contribution to the energy balance of a country. This paper analyzes the participation of ground source as RES, when the vertical (the probe in the ground and horizontal (registry in the ground heat exchangers are used for covering heating load of the building.

  6. Ground-State Density Profiles of One-Dimensional Bose Gases with Anisotropic Transversal Confinement

    Institute of Scientific and Technical Information of China (English)

    HAO Ya-Jiang

    2011-01-01

    We investigate the ground-state density distributions of interacting one-dimensional Bose gases with anisotropic transversal confinement.Combining the exact ground state energy density of homogeneous bose gases with local density approximation,we determine the density distribution in each interacting regime for different anisotropic parameters.It is shown that the transversal anisotropic parameter changes the density distribution obviously,and the observed density profiles on each orientation exhibit a difference of a factor.

  7. Impact of the variability of the seasonal snow cover on the ground surface regimes in Hurd Peninsula (Livingston Island, Antarctic)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2014-05-01

    Seasonally snow cover has a great impact on the thermal regime of the active layer and permafrost. Ground temperatures over a year are strongly affected by the timing, duration, thickness, structure and physical and thermal properties of snow cover. The purpose of this communication is to characterize the shallow ground thermal regimes, with special reference to the understanding of the influence snow cover in permafrost spatial distribution, in the ice-free areas of the north western part of Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". We have analyzed and ground temperatures as well as snow thickness data in four sites distributed along an altitudinal transect in Hurd Peninsula from 2007 to 2013: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). At each study site, data loggers were installed for the monitoring of air temperatures (at 1.5 m high), ground temperatures (5, 20 and 40 cm depth) and for snow depth (2, 5, 10, 20, 40, 80 and 160 cm) at 4-hour intervals. The winter data suggests the existence of three types of seasonal stages regarding the ground surface thermal regime and the thickness of snow cover: (a) shallow snow cover with intense ground temperatures oscillations; (b) thick snow cover and low variations of soil temperatures; and (c) stability of ground temperatures. Ground thermal conditions are also conditioned by a strong variability. Winter data indicates that Nuevo Incinerador site experiences more often thicker snow cover with higher ground temperatures and absence of ground temperatures oscillations. Collado Ramos and Ohridski show frequent variations of snow cover thickness, alternating between shallow snow cover with high ground temperature fluctuation and thick snow cover and low ground temperature fluctuation. Reina Sofia in all the years has thick snow cover with little variations in soil

  8. Mechanizing Weakly Ground Termination Proving of Term Rewriting Systems by Structural and Cover-Set Inductions

    Institute of Scientific and Technical Information of China (English)

    Su Feng

    2005-01-01

    The paper presents three formal proving methods for generalized weakly ground terminating property, i.e.,weakly terminating property in a restricted domain of a term rewriting system, one with structural induction, one with cover-set induction, and the third without induction, and describes their mechanization based on a meta-computation model for term rewriting systems-dynamic term rewriting calculus. The methods can be applied to non-terminating, nonconfluent and/or non-left-linear term rewriting systems. They can do "forward proving" by applying propositions in the proof, as well as "backward proving" by discovering lemmas during the proof.

  9. Evidence of wintertime CO2 emission from snow-covered grounds in high latitudes

    Institute of Scientific and Technical Information of China (English)

    方精云; 唐艳鸿KOIZUMI; Hiroshi(Division; of; Plant; Ecology; National; Institute; of; Agro-Environmental; Sciences; Tsukuba; 305; Japan)BEKKU; Yukiko(National; Polar; Institute; Tokyo; 192; Japan)

    1999-01-01

    In order to measure CO2 flux in wintertime arctic ecosystems, CO2 gas was sampled from various snow-covered grounds by using a closed chamber method during the First China Arctic Scientific Expedition from March to May in 1995. The CO2 gas samples were measured by using an infra-red analyzer (IRGA). The results showed that (ⅰ) CO2 emission was detected from all kinds of the snow-covered grounds, which provides direct evidence that the arctic tundra is functioning as a source of atmospheric CO2; (ⅱ) CO2 release was also detected from the permanent ice profile and icecap, and (ⅲ) CO2 evolution from terrestrial ecosystems in higher latitudes increased with an increase of surface temperature in accordance with the exponential function. This indicates a close coincidence with that under normal temperature conditions, and provides a useful method for predicting change in CO2 flux in the arctic ecosystems with the global climate change.

  10. AN ASSESSMENT OF CITIZEN CONTRIBUTED GROUND REFERENCE DATA FOR LAND COVER MAP ACCURACY ASSESSMENT

    Directory of Open Access Journals (Sweden)

    G. M. Foody

    2015-08-01

    Full Text Available It is now widely accepted that an accuracy assessment should be part of a thematic mapping programme. Authoritative good or best practices for accuracy assessment have been defined but are often impractical to implement. Key reasons for this situation are linked to the ground reference data used in the accuracy assessment. Typically, it is a challenge to acquire a large sample of high quality reference cases in accordance to desired sampling designs specified as conforming to good practice and the data collected are normally to some degree imperfect limiting their value to an accuracy assessment which implicitly assumes the use of a gold standard reference. Citizen sensors have great potential to aid aspects of accuracy assessment. In particular, they may be able to act as a source of ground reference data that may, for example, reduce sample size problems but concerns with data quality remain. The relative strengths and limitations of citizen contributed data for accuracy assessment are reviewed in the context of the authoritative good practices defined for studies of land cover by remote sensing. The article will highlight some of the ways that citizen contributed data have been used in accuracy assessment as well as some of the problems that require further attention, and indicate some of the potential ways forward in the future.

  11. Electromagnetic local density of states in graphene-covered porous silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ting [Department of Physics, Nanchang University, Nanchang 330031 (China); Wang, Tong-Biao, E-mail: tbwang@ncu.edu.cn [Department of Physics, Nanchang University, Nanchang 330031 (China); Liao, Qing-Hua; Liu, Jiang-Tao; Yu, Tian-Bao [Department of Physics, Nanchang University, Nanchang 330031 (China); Liu, Nian-Hua [Institute for Advanced Study, Nanchang University, Nanchang 330031 (China)

    2017-06-21

    Surface phonon polariton supported by silicon carbide (SiC) can be strongly coupled with graphene plasmon in the graphene-covered SiC bulk. The spectrum of the electromagnetic local density of states exhibits two peaks whose positions can be tuned by the chemical potential of graphene. In this work, we study the electromagnetic local density of states in the proximity of a graphene-covered SiC with periodic hole arrays. The well-known peak from the coupling of surface polariton supported by SiC and graphene plasmon splits into two. With increased volume ratio of holes, one of the split peak shifts towards high frequencies, whereas the other moves towards low frequencies. The dependence of split-peak positions on the chemical potential and permittivity of filling materials in the holes are also investigated. This study offers another method of modulating the electromagnetic local density of states. - Highlights: • The electromagnetic local density of states in the proximity of graphene-covered anisotropic SiC is firstly studied. • The peak from resonance of surface phonon polaritons in the EM-LDOS spectrum can be split into two. • The split peaks can be tuned by chemical potential, filling factor, and filling materials. • Our results provide a new method to modulate the EM-LDOS.

  12. Ground penetrating radar detection of subsnow liquid overflow on ice-covered lakes in interior Alaska

    Directory of Open Access Journals (Sweden)

    A. Gusmeroli

    2012-07-01

    Full Text Available Lakes are abundant throughout the pan-Arctic region. For many of these lakes ice cover lasts for up to two thirds of the year. This frozen cover allows human access to these lakes, which are therefore used for many subsistence and recreational activities, including water harvesting, fishing, and skiing. Safe access to these lakes may be compromised, however, when, after significant snowfall, the weight of the snow acts on the ice and causes liquid water to spill through weak spots and overflow at the snow-ice interface. Since visual detection of subsnow liquid overflow (SLO is almost impossible our understanding on SLO processes is still very limited and geophysical methods that allow SLO detection are desirable. In this study we demonstrate that a commercially available, lightweight 1GHz, ground penetrating radar system can detect and map extent and intensity of SLO. Radar returns from wet snow-ice interfaces are at least twice as much in strength than returns from dry snow-ice interface. The presence of SLO also affects the quality of radar returns from the base of the lake ice. During dry conditions we were able to profile ice thickness of up to 1 m, conversely, we did not retrieve any ice-water returns in areas affected by SLO.

  13. Effect of a Terminated Cover Crop and Aldicarb on Cotton Yield and Meloidogyne incognita Population Density.

    Science.gov (United States)

    Wheeler, T A; Leser, J F; Keeling, J W; Mullinix, B

    2008-06-01

    Terminated small grain cover crops are valuable in light textured soils to reduce wind and rain erosion and for protection of young cotton seedlings. A three-year study was conducted to determine the impact of terminated small grain winter cover crops, which are hosts for Meloidogyne incognita, on cotton yield, root galling and nematode midseason population density. The small plot test consisted of the cover treatment as the main plots (winter fallow, oats, rye and wheat) and rate of aldicarb applied in-furrow at-plant (0, 0.59 and 0.84 kg a.i./ha) as subplots in a split-plot design with eight replications, arranged in a randomized complete block design. Roots of 10 cotton plants per plot were examined at approximately 35 days after planting. Root galling was affected by aldicarb rate (9.1, 3.8 and 3.4 galls/root system for 0, 0.59 and 0.84 kg aldicarb/ha), but not by cover crop. Soil samples were collected in mid-July and assayed for nematodes. The winter fallow plots had a lower density of M. incognita second-stage juveniles (J2) (transformed to Log(10) (J2 + 1)/500 cm(3) soil) than any of the cover crops (0.88, 1.58, 1.67 and 1.75 Log(10)(J2 + 1)/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). There were also fewer M. incognita eggs at midseason in the winter fallow (3,512, 7,953, 8,262 and 11,392 eggs/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). Yield (kg lint per ha) was increased by application of aldicarb (1,544, 1,710 and 1,697 for 0, 0.59 and 0.84 kg aldicarb/ha), but not by any cover crop treatments. These results were consistent over three years. The soil temperature at 15 cm depth, from when soils reached 18 degrees C to termination of the grass cover crop, averaged 9,588, 7,274 and 1,639 centigrade hours (with a minimum threshold of 10 degrees C), in 2005, 2006 and 2007, respectively. Under these conditions, potential reproduction of M. incognita on the cover crop did not result in a yield penalty.

  14. Crop Ground Cover Fraction and Canopy Chlorophyll Content Mapping using RapidEye imagery

    Science.gov (United States)

    Zillmann, E.; Schonert, M.; Lilienthal, H.; Siegmann, B.; Jarmer, T.; Rosso, P.; Weichelt, T.

    2015-04-01

    Remote sensing is a suitable tool for estimating the spatial variability of crop canopy characteristics, such as canopy chlorophyll content (CCC) and green ground cover (GGC%), which are often used for crop productivity analysis and site-specific crop management. Empirical relationships exist between different vegetation indices (VI) and CCC and GGC% that allow spatial estimation of canopy characteristics from remote sensing imagery. However, the use of VIs is not suitable for an operational production of CCC and GGC% maps due to the limited transferability of derived empirical relationships to other regions. Thus, the operational value of crop status maps derived from remotely sensed data would be much higher if there was no need for reparametrization of the approach for different situations. This paper reports on the suitability of high-resolution RapidEye data for estimating crop development status of winter wheat over the growing season, and demonstrates two different approaches for mapping CCC and GGC%, which do not rely on empirical relationships. The final CCC map represents relative differences in CCC, which can be quickly calibrated to field specific conditions using SPAD chlorophyll meter readings at a few points. The prediction model is capable of predicting SPAD readings with an average accuracy of 77%. The GGC% map provides absolute values at any point in the field. A high R2 value of 80% was obtained for the relationship between estimated and observed GGC%. The mean absolute error for each of the two acquisition dates was 5.3% and 8.7%, respectively.

  15. Testing the enemies hypothesis in peach orchards in two different geographic areas in eastern China: the role of ground cover vegetation.

    Directory of Open Access Journals (Sweden)

    Nian-Feng Wan

    Full Text Available Many studies have supported the enemies hypothesis, which suggests that natural enemies are more efficient at controlling arthropod pests in polyculture than in monoculture agro-ecosystems. However, we do not yet have evidence as to whether this hypothesis holds true in peach orchards over several geographic locations. In the two different geographic areas in eastern China (Xinchang a town in the Shanghai municipality, and Hudai, a town in Jiangsu Province during a continuous three-year (2010-2012 investigation, we sampled arthropod pests and predators in Trifolium repens L. and in tree canopies of peach orchards with and without the ground cover plant T. repens. No significant differences were found in the abundances of the main groups of arthropod pests and predators in T. repens between Hudai and Xinchang. The abundance, richness, Simpson's index, Shannon-Wiener index, and Pielou evenness index of canopy predators in ground cover areas increased by 85.5, 27.5, 3.5, 16.7, and 7.9% in Xinchang, and by 87.0, 27.6, 3.5, 17.0 and 8.0% in Hudai compared to those in the controls, respectively. The average abundance of Lepidoptera, Coleoptera, Homoptera, true bugs and Acarina canopy pests in ground cover areas decreased by 9.2, 10.2, 17.2, 19.5 and 14.1% in Xinchang, and decreased by 9.5, 8.2, 16.8, 20.1 and 16.6% in Hudai compared to that in control areas, respectively. Our study also found a higher density of arthropod species resources in T. repens, as some omnivorous pests and predators residing in T. repens could move between the ground cover and the orchard canopy. In conclusion, ground cover in peach orchards supported the enemies hypothesis, as indicated by the fact that ground cover T. repens promoted the abundance and diversity of predators and reduced the number of arthropod pests in tree canopies in both geographical areas.

  16. Testing the enemies hypothesis in peach orchards in two different geographic areas in eastern China: the role of ground cover vegetation.

    Science.gov (United States)

    Wan, Nian-Feng; Ji, Xiang-Yun; Jiang, Jie-Xian

    2014-01-01

    Many studies have supported the enemies hypothesis, which suggests that natural enemies are more efficient at controlling arthropod pests in polyculture than in monoculture agro-ecosystems. However, we do not yet have evidence as to whether this hypothesis holds true in peach orchards over several geographic locations. In the two different geographic areas in eastern China (Xinchang a town in the Shanghai municipality, and Hudai, a town in Jiangsu Province) during a continuous three-year (2010-2012) investigation, we sampled arthropod pests and predators in Trifolium repens L. and in tree canopies of peach orchards with and without the ground cover plant T. repens. No significant differences were found in the abundances of the main groups of arthropod pests and predators in T. repens between Hudai and Xinchang. The abundance, richness, Simpson's index, Shannon-Wiener index, and Pielou evenness index of canopy predators in ground cover areas increased by 85.5, 27.5, 3.5, 16.7, and 7.9% in Xinchang, and by 87.0, 27.6, 3.5, 17.0 and 8.0% in Hudai compared to those in the controls, respectively. The average abundance of Lepidoptera, Coleoptera, Homoptera, true bugs and Acarina canopy pests in ground cover areas decreased by 9.2, 10.2, 17.2, 19.5 and 14.1% in Xinchang, and decreased by 9.5, 8.2, 16.8, 20.1 and 16.6% in Hudai compared to that in control areas, respectively. Our study also found a higher density of arthropod species resources in T. repens, as some omnivorous pests and predators residing in T. repens could move between the ground cover and the orchard canopy. In conclusion, ground cover in peach orchards supported the enemies hypothesis, as indicated by the fact that ground cover T. repens promoted the abundance and diversity of predators and reduced the number of arthropod pests in tree canopies in both geographical areas.

  17. Gas Transport Parameters for Landfill Final Cover Soil: Measurements and Model Modification by Dry Bulk Density

    Science.gov (United States)

    Wickramarachchi, P. N.; Kawamoto, K.; Hamamoto, S.; Nagamori, M.; Moldrup, P.; Komatsu, T.

    2011-12-01

    Landfill sites have been emerging in greenhouse warming scenarios as a significant source of atmospheric methane (CH4). Until recently, landfill management strategies have mainly addressed the problem of preventing groundwater contamination and reduction of leachate generation. Being one of the largest sources of anthropogenic CH4 emission, the final cover system should also be designed for minimizing the greenhouse gases migration into the atmosphere or the areas surrounding the landfill while securing the hydraulic performance. Compared to the intensive research efforts on hydraulic performances of landfill final cover soil, few studies about gas transport characteristics of landfill cover soils have been done. However, recent soil-gas studies implied that the effects of soil physical properties such as bulk density (i.e., compaction level), soil particle size are key parameters to understand landfill gaseous performance. The gas exchange through the final cover soils is controlled by advective and diffusive gas transport. Air permeability (ka) governs the advective gas transport while the soil-gas diffusion coefficient (Dp) governs diffusive gas transport. In this study, the effects of compaction level and particle size fraction effects on ka and Dp for landfill final cover soil was investigated. The disturbed soil samples were taken from landfill final cover in Japan. A compaction tests were performed for the soil samples with two different size fractions (content , the soil samples were repacked into soil cores (i.d. 15-cm, length 12-cm, 2120 cm3) at two different compaction levels [(MP):2700 kN/m2 and (SP):600 kN/m2]. After the compaction tests, ka and Dp were measured and then samples were saturated and subsequently drained at different soil-water matric potential of 0.98, 2.94, 9.81, 1235 kPa and with air-dried and oven-dried conditions. Results showed that measured Dp and ka values for the coarser (content. Further, compaction effort was much significant

  18. Citizen science land cover classification based on ground and satellite imagery: Case study Day River in Vietnam

    Science.gov (United States)

    Nguyen, Son Tung; Minkman, Ellen; Rutten, Martine

    2016-04-01

    Citizen science is being increasingly used in the context of environmental research, thus there are needs to evaluate cognitive ability of humans in classifying environmental features. With the focus on land cover, this study explores the extent to which citizen science can be applied in sensing and measuring the environment that contribute to the creation and validation of land cover data. The Day Basin in Vietnam was selected to be the study area. Different methods to examine humans' ability to classify land cover were implemented using different information sources: ground based photos - satellite images - field observation and investigation. Most of the participants were solicited from local people and/or volunteers. Results show that across methods and sources of information, there are similar patterns of agreement and disagreement on land cover classes among participants. Understanding these patterns is critical to create a solid basis for implementing human sensors in earth observation. Keywords: Land cover, classification, citizen science, Landsat 8

  19. Boots on the Ground: Troop Density in Contingency Operations

    Science.gov (United States)

    2006-01-01

    Singapore quickly prospered, and in 186 that port as well as Malacca and Penang , two small port enclaves on the western Malay coast, formally became the...operations was clearly indicated in statistical analyses maintained by the British com- mand.90 The British command formed larger Gurkha headquarters...displays the density statistics for the Balkans’ deployments. 5 Ta bl e 6. T ro op D en si ty in th e B al ka ns O pe ra tio ns M ili ta ry Fo

  20. Estimating Cotton Nitrogen Nutrition Status Using Leaf Greenness and Ground Cover Information

    Directory of Open Access Journals (Sweden)

    Farrah Melissa Muharam

    2015-05-01

    Full Text Available Assessing nitrogen (N status is important from economic and environmental standpoints. To date, many spectral indices to estimate cotton chlorophyll or N content have been purely developed using statistical analysis approach where they are often subject to site-specific problems. This study describes and tests a novel method of utilizing physical characteristics of N-fertilized cotton and combining field spectral measurements made at different spatial scales as an approach to estimate in-season chlorophyll or leaf N content of field-grown cotton. In this study, leaf greenness estimated from spectral measurements made at the individual leaf, canopy and scene levels was combined with percent ground cover to produce three different indices, named TCCLeaf, TCCCanopy, and TCCScene. These indices worked best for estimating leaf N at early flowering, but not for chlorophyll content. Of the three indices, TCCLeaf showed the best ability to estimate leaf N (R2 = 0.89. These results suggest that the use of green and red-edge wavelengths derived at the leaf scale is best for estimating leaf greenness. TCCCanopy had a slightly lower R2 value than TCCLeaf (0.76, suggesting that the utilization of yellow and red-edge wavelengths obtained at the canopy level could be used as an alternative to estimate leaf N in the absence of leaf spectral information. The relationship between TCCScene and leaf N was the lowest (R2 = 0.50, indicating that the estimation of canopy greenness from scene measurements needs improvement. Results from this study confirmed the potential of these indices as efficient methods for estimating in-season leaf N status of cotton.

  1. Water consumption and water-saving characteristics of a ground cover rice production system

    Science.gov (United States)

    Jin, Xinxin; Zuo, Qiang; Ma, Wenwen; Li, Sen; Shi, Jianchu; Tao, Yueyue; Zhang, Yanan; Liu, Yang; Liu, Xiaofei; Lin, Shan; Ben-Gal, Alon

    2016-09-01

    The ground cover rice production system (GCRPS) offers a potentially water-saving alternative to the traditional paddy rice production system (TPRPS) by furrow irrigating mulched soil beds and maintaining soils under predominately unsaturated conditions. The guiding hypothesis of this study was that a GCRPS would decrease both physiological and non-physiological water consumption of rice compared to a TPRPS while either maintaining or enhancing production. This was tested in a two-year field experiment with three treatments (TPRPS, GCRPSsat keeping root zone average soil water content near saturated, and GCRPS80% keeping root zone average soil water content as 80-100% of field water capacity) and a greenhouse experiment with four treatments (TPRPS, GCRPSsat, GCRPSfwc keeping root zone average soil water content close to field water capacity, and GCRPS80%). The water-saving characteristics of GCRPS were analyzed as a function of the measured soil water conditions, plant parameters regarding growth and production, and water input and consumption. In the field experiment, significant reduction in both physiological and non-physiological water consumption under GCRPS lead to savings in irrigation water of ∼61-84% and reduction in total input water of ∼35-47%. Compared to TPRPS, deep drainage was reduced ∼72-88%, evaporation was lessened ∼83-89% and transpiration was limited ∼6-10% under GCRPS. In addition to saving water, plant growth and grain yield were enhanced under GCRPS due to increased soil temperature in the root zone. Therefore, water use efficiencies (WUEs), based on transpiration, irrigation and total input water, were respectively improved as much as 27%, 609% and 110% under GCRPS. Increased yield attributed to up to ∼19%, decreased deep drainage accounted for ∼75%, decreased evaporation accounted for ∼14% and reduced transpiration for ∼5% of the enhancement in WUE of input water under GCRPS, while increased runoff and water storage had

  2. The role of snow cover in ground thermal conditions in three sites with contrasted topography in Sierra Nevada (Spain)

    Science.gov (United States)

    Oliva, Marc; Salvador, Ferran; Gómez Ortiz, Antonio; Salvà, Montserrat

    2014-05-01

    Snow cover has a high capacity to insulate the soil from the external thermal influences. In regions of high snowfall, such as the summit areas of the highest Iberian mountain ranges, the presence of a thick snow cover may condition the existence or inexistence of permafrost conditions. In order to analyze the impact of the thickness, duration and interannual variability of snow cover on the ground thermal regime in the massif of Sierra Nevada, we have analyzed soil temperatures at a depth of 2 cm for the period 2006-2012 in three sites of contrasting topography as well as air temperatures for the same period: (a) Corral del Veleta (3100 m) in a rock glacier located in the northern Veleta cirque, with high and persistent snow cover. (b) Collado de los Machos (3300 m), in a summit area with relict stone circles, with little snow accumulation due to wind effect. (c) Río Seco (3000 m), in a solifluction lobe located in this southern glacial cirque with moderate snowfall. Considering the air and 2 cm depth soil temperature records, the freezing degree-days were calculated for each year from November to May in order to characterize the role of snow as a thermal insulator of the ground during the cold season (Frauenfeld et al., 2007). In all cases, the highest values of freezing degree-days correspond to years with little snowfall (2006-2007, 2007-2008, 2011-2012), while in years with a thicker snow cover (2008-2009, 2009-2010, 2010-2011) the total freezing degree-days were significantly lower. The accumulation of freezing degree-days is maximum at the wind-exposed site of Collado de los Machos, where the wind redistributes snow and favours the penetration of cold into the ground. The opposite pattern occurs in the Veleta cirque, where most persistent snow cover conditions determine lower accumulated freezing degree-days than in Collado de los Machos and Rio Seco.

  3. Ground State Density Distribution of Bose-Fermi Mixture in a One-Dimensional Harmonic Trap

    Institute of Scientific and Technical Information of China (English)

    HAO Ya-Jiang

    2011-01-01

    By the density-functional calculation we investigate the ground-state properties of Bose-Fermi mixture confined in one-dimensional harmonic traps. The homogeneous mixture of bosons and polarized fermions with contact interaction can be exactly solved by the Bethe-ansatz method. After giving the exact formula of ground state energy density, we employ the local-density approximation to determine the density distribution of each component. It is shown that with the increase in interaction, the total density distribution evolves to Fermi-like distribution and the system exhibits phase separation between two components when the interaction is strong enough but finite. While in the infinite interaction limit both bosons and fermions display the completely same Fermi-like distributions and phase separation disappears.

  4. Assessing alternative measures of tree canopy cover: Photo-interpreted NAIP and ground-based estimates

    Science.gov (United States)

    Chris Toney; Greg Liknes; Andy Lister; Dacia Meneguzzo

    2012-01-01

    In preparation for the development of the National Land Cover Database (NLCD) 2011 tree canopy cover layer, a pilot project for research and method development was completed in 2010 by the USDA Forest Service Forest Inventory and Analysis (FIA) program and Remote Sensing Applications Center (RSAC).This paper explores one of several topics investigated during the NLCD...

  5. Ly$\\alpha$ emission from Green Peas: the role of circumgalactic gas density, covering, and kinematics

    CERN Document Server

    Henry, Alaina; Martin, Crystal; Erb, Dawn

    2015-01-01

    We report Hubble Space Telescope/Cosmic Origins Spectrograph observations of the Ly$\\alpha$ emission and interstellar absorption lines in a sample of ten star-forming galaxies at z~0.2. Selected on the basis of high equivalent width optical emission lines, the sample, dubbed "Green Peas," make some of the best analogs for young galaxies in an early Universe. We detect Ly$\\alpha$ emission in all ten galaxies, and 9/10 show double-peaked line profiles suggestive of low H I column density. We measure Ly$\\alpha$/H$\\alpha$ flux ratios of 0.5-5.6, implying that 5% to 60% of Ly$\\alpha$ photons escape the galaxies. These data confirm previous findings that low-ionization metal absorption (LIS) lines are weaker when Ly$\\alpha$ escape fraction and equivalent width are higher. However, contrary to previously favored interpretations of this trend, increased Ly$\\alpha$ output cannot be the result of a varying H I covering: the Lyman absorption lines (Ly$\\beta$ and higher) show a covering fraction near unity for gas with N...

  6. v-representability and density functional theory. [for nonrelativistic electrons in nondegenerate ground state

    Science.gov (United States)

    Kohn, W.

    1983-01-01

    It is shown that if n(r) is the discrete density on a lattice (enclosed in a finite box) associated with a nondegenerate ground state in an external potential v(r) (i.e., is 'v-representable'), then the density n(r) + mu(r), with m(r) arbitrary (apart from trivial constraints) and mu small enough, is also associated with a nondegenerate ground state in an external potential v'(r) near v(r); i.e., n(r) + m(r) is also v-representable. Implications for the Hohenberg-Kohn variational principle and the Kohn-Sham equations are discussed.

  7. Quantifying the impact of cloud cover on ground radiation flux measurements using hemispherical images

    NARCIS (Netherlands)

    Roupioz, L.; Colin, J.; Jia, L.; Nerry, F.; Menenti, M.

    2015-01-01

    Linking observed or estimated ground incoming solar radiation with cloud coverage is difficult since the latter is usually poorly described in standard meteorological observation protocols. To investigate the benefits of detailed observation and characterization of cloud coverage and distribution

  8. Density-matrix-functional calculations for matter in strong magnetic fields: Ground states of heavy atoms

    DEFF Research Database (Denmark)

    Johnsen, Kristinn; Yngvason, Jakob

    1996-01-01

    and the electron number N tend to infinity with N/Z fixed, and the magnetic field B tends to infinity in such a way that B/Z4/3→∞. We have calculated electronic density profiles and ground-state energies for values of the parameters that prevail on neutron star surfaces and compared them with results obtained...

  9. The density of the rock covering Gran Sasso Laboratories in Central Apennines, Italy by underground gravity measurements

    Science.gov (United States)

    Capuano, P.; De Luca, G.; Di Sena, F.; Gasparini, P.; Scarpa, R.

    1998-05-01

    Various nuclear physics experiments are being carried out in the Istituto Nazionale di Fisica Nucleare Laboratories that have been excavated in the Gran Sasso Massif in the Italian Apennines. These experiments make use of the shield effect provided by a 1400-m-thick rock cover that absorb cosmic rays. It is important to know the real density of the rock cover and the extent of its lateral variation. The density of different sections of the rock cover was determined using the correlation between measured underground gravity data and thickness of the rock cover. Observed gravity was corrected using a 3D model, for the mass deficiency covered by excavation of highway tunnels and the cavities that house the laboratories. The average density of the rock cover was found to be 2720±50 kg m -3. Lateral variations are contained within the uncertainty for most of the sections, except for two sections where densities are lowered by as much as 11% because of the presence of a shallow layer formed by loose Quaternary sediments.

  10. The In-Transit Vigilant Covering Tour Problem of Routing Unmanned Ground Vehicles

    Science.gov (United States)

    2012-08-01

    15 Figure 2. A classic VRP ...17 Figure 3. Solution for a VRP ........................................................................................18 Figure 4. Solution...of NP-hard problems, such as the Traveling Salesman Problem (TSP), Vehicle Routing Problem ( VRP ), and Covering Salesman Problem (CSP) etc. We will

  11. Mapping wind erosion hazard in Australia using MODIS-derived ground cover, soil moisture and climate data

    Science.gov (United States)

    Yang, X.; Leys, J.

    2014-03-01

    This paper describes spatial modeling methods to identify wind erosion hazard (WEH) areas across Australia using the recently available time-series products of satellite-derived ground cover, soil moisture and wind speed. We implemented the approach and data sets in a geographic information system to produce WEH maps for Australia at 500 m ground resolution on a monthly basis for the recent thirteen year period (2000-2012). These maps reveal the significant wind erosion hazard areas and their dynamic tendencies at paddock and regional scales. Dust measurements from the DustWatch network were used to validate the model and interpret the dust source areas. The modeled hazard areas and changes were compared with results from a rule-set approach and the Computational Environmental Management System (CEMSYS) model. The study demonstrates that the time series products of ground cover, soil moisture and wind speed can be jointly used to identify landscape erodibility and to map seasonal changes of wind erosion hazard across Australia. The time series wind erosion hazard maps provide detailed and useful information to assist in better targeting areas for investments and continuous monitoring, evaluation and reporting that will lead to reduced wind erosion and improved soil condition.

  12. Eliminating Trapping Sets in Low-Density Parity Check Codes by using Tanner Graph Covers

    CERN Document Server

    Vasic, Milos Ivkovic Shashi Kiran Chilappagari Bane

    2008-01-01

    We discuss error floor asympotics and present a method for improving the performance of low-density parity check (LDPC) codes in the high SNR (error floor) region. The method is based on Tanner graph covers that do not have trapping sets from the original code. The advantages of the method are that it is universal, as it can be applied to any LDPC code/channel/decoding algorithm and it improves performance at the expense of increasing the code length, without losing the code regularity, without changing the decoding algorithm, and, under certain conditions, without lowering the code rate. The proposed method can be modified to construct convolutional LDPC codes also. The method is illustrated by modifying Tanner, MacKay and Margulis codes to improve performance on the binary symmetric channel (BSC) under the Gallager B decoding algorithm. Decoding results on AWGN channel are also presented to illustrate that optimizing codes for one channel/decoding algorithm can lead to performance improvement on other chann...

  13. Relativistic analysis of nuclear ground state densities at 135 to 200 MeV

    Indian Academy of Sciences (India)

    M A Suhail; N Neeloffer; Z A Khan

    2005-12-01

    A relativistic analysis of p + 40Ca elastic scattering with different nuclear ground state target densities at 135 to 200 MeV is presented in this paper. It is found that the IGO densities are more consistent in reproducing the data over the energy range considered here. The reproduction of spin-rotation-function data with the simultaneous fitting of differential cross-section and analyzing power, and the appearance of wine-bottle-bottom shaped Re eff() in the transition energy region, sensitively depends on the input nuclear ground state densities and are not solely the relativistic characteristic signatures. We also found that the wine-bottle-bottom shaped Re eff() is preferred by the spin observables in the transition energy region (i.e. 181 MeV to 200 MeV).

  14. Nuclear level densities with pairing and self-consistent ground-state shell effects

    CERN Document Server

    Arnould, M

    1981-01-01

    Nuclear level density calculations are performed using a model of fermions interacting via the pairing force, and a realistic single particle potential. The pairing interaction is treated within the BCS approximation with different pairing strength values. The single particle potentials are derived in the framework of an energy-density formalism which describes self-consistently the ground states of spherical nuclei. These calculations are extended to statistically deformed nuclei, whose estimated level densities include rotational band contributions. The theoretical results are compared with various experimental data. In addition, the level densities for several nuclei far from stability are compared with the predictions of a back-shifted Fermi gas model. Such a comparison emphasizes the possible danger of extrapolating to unknown nuclei classical level density formulae whose parameter values are tailored for known nuclei. (41 refs).

  15. Permafrost, Seasonally Frozen Ground, Snow Cover and Vegetation in the USSR

    Science.gov (United States)

    1984-12-01

    Late Quaternary History and the Formation of Sedi- ments in the Marginal and Inland Seas (Pozdnechetvertichnaia Istorlia i Sedimentogenez...rasprostraneniia snezhnogo pokrova na poverkhnosti sushi zemnogo shara). In Geography of Snow Cover (Geo- grafiya Snezhnogo Prokrova). Moscow: Izdat...Papers, 18(3): 198-202. (36-1668) Vigdorchik, M.E. (1980) Arctic Pleistocene History and the Development of Submarine Permafrost. Boulder

  16. [Effects of ground cover and water-retaining agent on winter wheat growth and precipitation utilization].

    Science.gov (United States)

    Wu, Ji-Cheng; Guan, Xiu-Juan; Yang, Yong-Hui

    2011-01-01

    An investigation was made at a hilly upland in western Henan Province to understand the effects of water-retaining agent (0, 45, and 60 kg x hm(-2)), straw mulching (3000 and 6000 kg x hm(-2)), and plastic mulching (thickness straw- or plastic mulching was combined with the use of water-retaining agent. Comparing with the control, all the measures increased the soil moisture content at different growth stages by 0.1%-6.5%. Plastic film mulching had the best water-retention effect before jointing stage, whereas water-retaining agent showed its best effect after jointing stage. Soil moisture content was the lowest at flowering and grain-filling stages. Land cover increased the grain yield by 2.6%-20.1%. The yield increment was the greatest (14.2%-20.1%) by the combined use of straw mulching and water-retaining agent, followed by plastic mulching combined with water-retaining agent (11.9% on average). Land cover also improved the precipitation use efficiency (0.4-3.2 kg x mm(-1) x hm(-2)) in a similar trend as the grain yield. This study showed that land cover and water-retaining agent improved soil moisture and nutrition conditions and precipitation utilization, which in turn, promoted the tillering of winter wheat, and increased the grain number per ear and the 1000-grain mass.

  17. The Impact of Time Difference between Satellite Overpass and Ground Observation on Cloud Cover Performance Statistics

    Directory of Open Access Journals (Sweden)

    Jędrzej S. Bojanowski

    2014-12-01

    Full Text Available Cloud property data sets derived from passive sensors onboard the polar orbiting satellites (such as the NOAA’s Advanced Very High Resolution Radiometer have global coverage and now span a climatological time period. Synoptic surface observations (SYNOP are often used to characterize the accuracy of satellite-based cloud cover. Infrequent overpasses of polar orbiting satellites combined with the 3- or 6-h SYNOP frequency lead to collocation time differences of up to 3 h. The associated collocation error degrades the cloud cover performance statistics such as the Hanssen-Kuiper’s discriminant (HK by up to 45%. Limiting the time difference to 10 min, on the other hand, introduces a sampling error due to a lower number of corresponding satellite and SYNOP observations. This error depends on both the length of the validated time series and the SYNOP frequency. The trade-off between collocation and sampling error call for an optimum collocation time difference. It however depends on cloud cover characteristics and SYNOP frequency, and cannot be generalized. Instead, a method is presented to reconstruct the unbiased (true HK from HK affected by the collocation differences, which significantly (t-test p < 0.01 improves the validation results.

  18. Effect of heavy metals on seed germination and seedling growth of common ragweed and roadside ground cover legumes.

    Science.gov (United States)

    Bae, Jichul; Benoit, Diane L; Watson, Alan K

    2016-06-01

    In southern Québec, supplement roadside ground covers (i.e. Trifolium spp.) struggle to establish near edges of major roads and thus fail to assist turf recruitment. It creates empty niches vulnerable to weed establishment such as common ragweed (Ambrosia artemisiifolia). We hypothesized that heavy metal stresses may drive such species shifts along roadside edges. A growth chamber experiment was conducted to assess effects of metals (Zn, Pb, Ni, Cu, and Cd) on germination and seedling behaviors of roadside weed (A. artemisiifolia) and ground cover legumes (Coronilla varia, Lotus corniculatus, and Trifolium arvense). All metals inhibited T. arvense germination, but the effect was least on A. artemisiifolia. Low levels of Pb and Ni promoted germination initiation of A. artemisiifolia. Germination of L. corniculatus was not affected by Zn, Pb, and Ni, but inhibited by Cu and Cd. Germination of C. varia was decreased by Ni, Cu, and Cd and delayed by Zn and Pb. Metal additions hindered seedling growth of all test species, and the inhibitory effect on the belowground growth was greater than on the aboveground growth. Seedling mortality was lowest in A. artemisiifolia but highest in T. arvense when exposed to the metal treatments. L. corniculatus and C. varia seedlings survived when subjected to high levels of Zn, Pb, and Cd. In conclusion, the successful establishment of A. artemisiifolia along roadside edges can be associated with its greater tolerance of heavy metals. The findings also revealed that L. corniculatus is a potential candidate for supplement ground cover in metal-contaminated roadside edges in southern Québec, especially sites contaminated with Zn and Pb.

  19. Comparing distinct ground-based lightning location networks covering the Netherlands

    Science.gov (United States)

    de Vos, Lotte; Leijnse, Hidde; Schmeits, Maurice; Beekhuis, Hans; Poelman, Dieter; Evers, Läslo; Smets, Pieter

    2015-04-01

    Lightning can be detected using a ground-based sensor network. The Royal Netherlands Meteorological Institute (KNMI) monitors lightning activity in the Netherlands with the so-called FLITS-system; a network combining SAFIR-type sensors. This makes use of Very High Frequency (VHF) as well as Low Frequency (LF) sensors. KNMI has recently decided to replace FLITS by data from a sub-continental network operated by Météorage which makes use of LF sensors only (KNMI Lightning Detection Network, or KLDN). KLDN is compared to the FLITS system, as well as Met Office's long-range Arrival Time Difference (ATDnet), which measures Very Low Frequency (VLF). Special focus lies on the ability to detect Cloud to Ground (CG) and Cloud to Cloud (CC) lightning in the Netherlands. Relative detection efficiency of individual flashes and lightning activity in a more general sense are calculated over a period of almost 5 years. Additionally, the detection efficiency of each system is compared to a ground-truth that is constructed from flashes that are detected by both of the other datasets. Finally, infrasound data is used as a fourth lightning data source for several case studies. Relative performance is found to vary strongly with location and time. As expected, it is found that FLITS detects significantly more CC lightning (because of the strong aptitude of VHF antennas to detect CC), though KLDN and ATDnet detect more CG lightning. We analyze statistics computed over the entire 5-year period, where we look at CG as well as total lightning (CC and CG combined). Statistics that are considered are the Probability of Detection (POD) and the so-called Lightning Activity Detection (LAD). POD is defined as the percentage of reference flashes the system detects compared to the total detections in the reference. LAD is defined as the fraction of system recordings of one or more flashes in predefined area boxes over a certain time period given the fact that the reference detects at least one

  20. After the fire: benefits of reduced ground cover for vervet monkeys (Cercopithecus aethiops).

    Science.gov (United States)

    Jaffe, Karin Enstam; Isbell, Lynne A

    2009-03-01

    Here we describe changes in ranging behavior and other activities of vervet monkeys (Cercopithecus aethiops) after a wildfire eliminated grass cover in a large area near the study group's home range. Soon after the fire, the vervets ranged farther away from tall trees that provide refuge from mammalian predators, and moved into the burned area where they had never been observed to go before the fire occurred. Visibility at vervet eye-level was 10 times farther in the burned area than in unburned areas. They traveled faster, and adult females spent more time feeding and less time scanning bipedally in the burned area than in the unburned area. The burned area's greater visibility may have lowered the animals' perceived risk of predation there, and may have provided them with an unusual opportunity to eat acacia ants.

  1. A phenomenological model of the muon density profile on the ground of very inclined air showers

    Science.gov (United States)

    Dembinski, H. P.; Billoir, P.; Deligny, O.; Hebbeker, T.

    2010-09-01

    Ultra-high energy cosmic rays generate extensive air showers in Earth's atmosphere. A standard approach to reconstruct the energy of an ultra-high energy cosmic rays is to sample the lateral profile of the particle density on the ground of the air shower with an array of surface detectors. For cosmic rays with large inclinations, this reconstruction is based on a model of the lateral profile of the muon density observed on the ground, which is fitted to the observed muon densities in individual surface detectors. The best models for this task are derived from detailed Monte-Carlo simulations of the air shower development. We present a phenomenological parametrization scheme which allows to derive a model of the average lateral profile of the muon density directly from a fit to a set of individual Monte-Carlo simulated air showers. The model reproduces the detailed simulations with a high precision. As an example, we generate a muon density model which is valid in the energy range 10 18 eV < E < 10 20 eV and the zenith angle range 60°<θ<90°. We will further demonstrate a way to speed up the simulation of such muon profiles by three orders of magnitude, if only the muons in the shower are of interest.

  2. Temporal monitoring of the soil freeze-thaw cycles over snow-cover land by using off-ground GPR

    KAUST Repository

    Jadoon, Khan

    2013-07-01

    We performed off-ground ground-penetrating radar (GPR) measurements over a bare agricultural field to monitor the freeze-thaw cycles over snow-cover. The GPR system consisted of a vector network analyzer combined with an off-ground monostatic horn antenna, thereby setting up an ultra-wideband stepped-frequency continuous-wave radar. Measurements were performed during nine days and the surface of the bare soil was exposed to snow fall, evaporation and precipitation as the GPR antenna was mounted 110 cm above the ground. Soil surface dielectric permittivity was retrieved using an inversion of time-domain GPR data focused on the surface reflection. The GPR forward model used combines a full-waveform solution of Maxwell\\'s equations for three-dimensional wave propagation in planar layered media together with global reflection and transmission functions to account for the antenna and its interactions with the medium. Temperature and permittivity sensors were installed at six depths to monitor the soil dynamics in the top 8 cm depth. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and permittivity data and in particular freeze and thaw events were clearly visible. A good agreement of the trend was observed between the temperature, permittivity and GPR time-lapse data with respect to five freeze-thaw cycles. The GPR-derived permittivity was in good agreement with sensor observations. The proposed method appears to be promising for the real-time mapping and monitoring of the frozen layer at the field scale. © 2013 IEEE.

  3. Direct effects of tillage on the activity density of ground beetle (Coleoptera: Carabidae) weed seed predators.

    Science.gov (United States)

    Shearin, A F; Reberg-Horton, S C; Gallandt, E R

    2007-10-01

    Ground beetles are well known as beneficial organisms in agroecosystems, contributing to the predation of a wide range of animal pests and weed seeds. Tillage has generally been shown to have a negative effect on ground beetles, but it is not known whether this is because of direct mortality or the result of indirect losses resulting from dispersal caused by habitat deterioration. In 2005, field experiments measured direct, tillage-induced mortality, of four carabid weed seed predators, Harpalus rufipes DeGeer, Agonum muelleri Herbst, Anisodactylus merula Germar, and Amara cupreolata Putzeys, and one arthropod predator, Pterostichus melanarius Illiger, common to agroecosystems in the northeastern United States. Three tillage treatments (moldboard plow, chisel plow, and rotary tillage) were compared with undisturbed controls at two sites (Stillwater and Presque Isle) and at two dates (July and August) in Maine. Carabid activity density after disturbance was measured using fenced pitfall traps installed immediately after tillage to remove any effects of dispersal. Rotary tillage and moldboard plowing reduced weed seed predator activity density 52 and 54%, respectively. Carabid activity density after chisel plowing was similar to the undisturbed control. This trend was true for each of the weed seed predator species studied. However, activity density of the arthropod predator P. melanarius was reduced by all tillage types, indicating a greater sensitivity to tillage than the four weed seed predator species. These results confirm the need to consider both direct and indirect effects of management in studies of invertebrate seed predators.

  4. The role of rabbit density and the diversity of weeds in the development of cover crops in olive groves

    Directory of Open Access Journals (Sweden)

    José Guerrero-Casado

    2015-09-01

    Full Text Available Cover crops are an effective means to reduce soil erosion and to provide food and shelter for wildlife. However, in areas of intensive farming, which are characterised by the scarcity of weed communities, wild herbivores may focus their grazing on cover crops, which could make their implementation difficult. In this work, we test whether rabbit grazing can prevent the growth of herbaceous cover crops in olive groves in Southern Spain in addition to assessing the role of rabbit abundance and diversity of weeds in the development of cover crops. This question has been addressed by sowing Bromus rubens between the rows of five olive groves in Cordoba province (Spain. We then monitored the surface covered by B. rubens, along with both diversity of weed communities and rabbit abundance. Two rabbit exclusion areas were also placed in each olive grove in order to assess the impact of rabbits on the development of cover crops. Our results showed that the surface occupied by B. rubens was considerably higher in the rabbit exclusion areas (mean 56.8 ± 5.65 % than in those areas in which they could feed (mean 35.6 ± 4.32 %. The coverage occupied by cover crops was higher in areas with lower rabbit density, although this relationship was modulated by the weed diversity index, since in areas with the same rabbit abundance the coverage was higher in those with a richer weed community. These findings suggest that high rabbit abundances can prevent the development of herbaceous cover crops in olive groves, particularly in areas in which alternative food resources (measured as weed diversity are scarce.

  5. The role of rabbit density and the diversity of weeds in the development of cover crops in olive groves

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Casado, J.; Carpio, A.J.; Prada, L.M.; Tortosa, F.S.

    2015-07-01

    Cover crops are an effective means to reduce soil erosion and to provide food and shelter for wildlife. However, in areas of intensive farming, which are characterised by the scarcity of weed communities, wild herbivores may focus their grazing on cover crops, which could make their implementation difficult. In this work, we test whether rabbit grazing can prevent the growth of herbaceous cover crops in olive groves in Southern Spain in addition to assessing the role of rabbit abundance and diversity of weeds in the development of cover crops. This question has been addressed by sowing Bromus rubens between the rows of five olive groves in Cordoba province (Spain). We then monitored the surface covered by B. rubens, along with both diversity of weed communities and rabbit abundance. Two rabbit exclusion areas were also placed in each olive grove in order to assess the impact of rabbits on the development of cover crops. Our results showed that the surface occupied by B. rubens was considerably higher in the rabbit exclusion areas (mean 56.8 ± 5.65 %) than in those areas in which they could feed (mean 35.6 ± 4.32 %). The coverage occupied by cover crops was higher in areas with lower rabbit density, although this relationship was modulated by the weed diversity index, since in areas with the same rabbit abundance the coverage was higher in those with a richer weed community. These findings suggest that high rabbit abundances can prevent the development of herbaceous cover crops in olive groves, particularly in areas in which alternative food resources (measured as weed diversity) are scarce. (Author)

  6. Semilocal and Hybrid Density Embedding Calculations of Ground-State Charge-Transfer Complexes

    CERN Document Server

    Laricchia, S; Della Sala, F; 10.1063/1.4795825

    2013-01-01

    We apply the frozen density embedding method, using a full relaxation of embedded densities through a freeze-and-thaw procedure, to study the electronic structure of several benchmark ground-state charge-transfer complexes, in order to assess the merits and limitations of the approach for this class of systems. The calculations are performed using both semilocal and hybrid exchange-correlation (XC) functionals. The results show that embedding calculations using semilocal XC functionals yield rather large deviations with respect to the corresponding supermolecular calculations. Due to a large error cancellation effect, however, they can often provide a relatively good description of the electronic structure of charge-transfer complexes, in contrast to supermolecular calculations performed at the same level of theory. On the contrary, when hybrid XC functionals are employed, both embedding and supermolecular calculations agree very well with each other and with the reference benchmark results. In conclusion, fo...

  7. Sub-pixel estimation of tree cover and bare surface densities using regression tree analysis

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Zangrando Toneli

    2011-09-01

    Full Text Available Sub-pixel analysis is capable of generating continuous fields, which represent the spatial variability of certain thematic classes. The aim of this work was to develop numerical models to represent the variability of tree cover and bare surfaces within the study area. This research was conducted in the riparian buffer within a watershed of the São Francisco River in the North of Minas Gerais, Brazil. IKONOS and Landsat TM imagery were used with the GUIDE algorithm to construct the models. The results were two index images derived with regression trees for the entire study area, one representing tree cover and the other representing bare surface. The use of non-parametric and non-linear regression tree models presented satisfactory results to characterize wetland, deciduous and savanna patterns of forest formation.

  8. First-order density matrix as a functional of the ground-state electron density for harmonic confinement of two electrons which also interact harmonically

    Energy Technology Data Exchange (ETDEWEB)

    March, N.H

    2002-12-30

    The first-order density matrix {gamma}(r{sub 1},r{sub 2}) for the ground-state of a model two-electron atom is explicitly constructed from the electron density {rho}(r). The model has harmonic confinement plus interparticle harmonic interactions. {gamma}(r{sub 1},r{sub 2}) and {rho}(r) are related non-locally, even though no density gradients and no quadratures appear.

  9. Variations in vegetation cover and topography control gully density and sediment production on the Chinese Loess Plateau

    Science.gov (United States)

    Zhao, Jianlin; Govers, Gerard

    2016-04-01

    The factors controlling topsoil erosion rates are relatively well understood. This explains why topsoil erosion rates on the Chinese loess plateau (CLP) can be relatively accurately estimated using a combination of empirical data and relatively simple models (Zhao et al., in press). This is, however, not the case for non-topsoil erosion (sediment production by gullying and landslides): while it is well known that these processes produce significant amounts of sediment, the factors controlling their intensity on the CLP are far less understood. In this study, the contribution of non-topsoil erosion to total sediment production on the CLP was investigated. We estimated non-topsoil erosion rates (ENT) by making the difference between measured total sediment yield and the estimated topsoil erosion in 46 gauged catchments on the CLP for the period 1950-1970, when soil conservation measures were mostly absent in the area. We tested an extensive set of environmental variables related to topography, climate and the impact of land use for correlation Our results showed that the average catchment erosion rate (E) and ENT between 1950 and 1970 were 68.29 tha-1yr-1 and 58.02 tha-1yr-1 respectively. The sediment contribution of non-topsoil erosion to total sediment production ranged between 0 and 97% with a mean of 70%. Both E and ENT were significantly related with river slope, land use, NDVI, and gully density. However, gully density was the only variable explaining a major part of the variance in both E (60%) and ENT (57%). Gully density itself was significantly related to topography and vegetation cover but not to precipitation. Importantly, gully density was not only related to overall slope steepness, but also the river gradients and the hypsometric integral, suggesting that not only land cover disturbance but also tectonic uplift may control gully density and erosion rates. The absence of a clear climate signal, both with respect to the variation in gully density and in

  10. Vegetation cover and topography rather than human disturbance control gully density and sediment production on the Chinese Loess Plateau

    Science.gov (United States)

    Zhao, Jianlin; Vanmaercke, Matthias; Chen, Longqian; Govers, Gerard

    2016-12-01

    The factors controlling topsoil erosion rates on the Chinese Loess Plateau (CLP) are currently relatively well understood and topsoil erosion rates can now be relatively accurately estimated. This is, however, not the case for non-topsoil erosion (sediment production by gullying and landslides): while it is well known that these processes produce significant amounts of sediment, the factors controlling their intensity and spatial distribution on the CLP are less well understood. In this study we quantified the contribution of non-topsoil erosion to total sediment production on the CLP and investigated which factors control spatial and temporal variations in non-topsoil erosion. We estimated non-topsoil erosion rates (ENT) by comparing the measured average sediment yields of 46 gauged catchments for the 1950-1970 period, when soil conservation measures were nearly absent in the area, with predicted topsoil erosion rates (using a recently developed empirical model). In addition, gully density was estimated in each catchment using Google Earth data. Our results showed that the area-weighted average catchment erosion rate (E) and ENT were 58.60 ± 51.80 and 48.68 ± 49.78 t ha- 1 yr- 1 respectively for the studied catchments. The sediment contribution of non-topsoil erosion to total sediment production ranged between ca. 0 and 97% with a mean of 70 ± 25%. Both E and ENT were significantly correlated to longitudinal river slope, land use, NDVI, and gully density. However, gully density was the only variable explaining a major part of the variance in both E (60%) and ENT (57%). Gully density itself was significantly related to topography and vegetation cover but not to rainfall erosivity. Importantly, gully density was not only related to overall slope steepness, but also to the longitudinal slope of the river network and the hypsometric integral, suggesting that not only land cover disturbance but also tectonic uplift controls gully density and erosion rates. The

  11. Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains, northeastern China

    Institute of Scientific and Technical Information of China (English)

    XiaoLi Chang; HuiJun Jin; YanLin Zhang; HaiBin Sun

    2015-01-01

    Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of the soils in permafrost regions in the mid-latitudes and boreal regions, such as that on the western flank of the Da Xing'anling (Hinggan) Mountains, northeastern China. This paper gives a detailed analysis on meteorological data series from 2001 to 2010 provided by the Gen'he Weather Station, which is located in a talik of discontinuous permafrost zone and with sparse meadow on the observation field. It is inferred that snow cover is important for the ground thermal regime in the middle Da Xing'anling Mountains. Snow cover of 10-cm in thickness and five to six months in duration (generally November to next March) can reduce the heat loss from the ground to the atmosphere by 28%, and by 71% if the snow depth increases to 36 cm. Moreover, the occurrence of snow cover resulted in mean annual ground surface temperatures 4.7–8.2°C higher than the mean annual air temperatures recorded at the Gen'he Weather Station. The beginning date for stable snow cover establishment (SE date) and the initial snow depth (SDi) also had a great influences on the ground freezing process. Heavy snowfall before ground surface freeze-up could postpone and retard the freezing process in Gen'he. As a result, the duration of ground freezing was shortened by at least 20 days and the maximum depth of frost penetration was as much as 90 cm shallower.

  12. Unmasking the soil cover's disruption by use of a dynamic model of measurement aerospace parameters of ground vegetation

    Directory of Open Access Journals (Sweden)

    E. V. Vysotskaya

    2016-03-01

    Full Text Available The "Introduction" describes topicality and importance of revealing the soil cover's disruption for a wide range of fields. It was shown that spectral brightness and colorimetric parameters of ground vegetation can be used for this task. However, a traditional scheme of data processing for remote sensing requires a long-term observations and can not always be applied, if quick decision-making is necessary or there is lack of information. Such cases require the use of special methods, one of which is a dynamic model developed with authors' participation based on the following basic relationships: (+,- (-, - (+, 0, (-, 0 (0,0. The section "Brief description of a dynamic model" describes the basic principles of dynamic systems used to solve the problem. Using above-mentioned relationships, the dynamics of a system consisting of several components is constructed and its main properties are listed. The main feature of this model is that the identification of structure and parameters of the dynamic system does not required sequential order of observations (as for models based on time series. This feature of the model enables for identifying the system's parameters of dynamics of the natural system to use information from a single picture taken from the spacecraft rather than long-term observations. The section "Materials and Methods" describes specific colorimetric parameters used to analyze the vegetation cover. The section "Obtained results" contains an example of the model's application to a satellite image for detecting the differences in two sites of a field with vegetation. One site is a recultivated area near the liquidated gas-oil well, another site is non-recultivated area at a considerable distance from the well (500-1000 m. The simulation results are described by eight signed graphs (4 graphs for each sites, whose structure allows to identify the system differences between the two cases. The section "Conclusions" summarizes the results of

  13. LAND-COVER DENSITY-BASED APPROACH TO URBAN LAND USE MAPPING USING HIGH-RESOLUTION IMAGERY

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiu-ying; FENG Xue-zhi; DENG Hui

    2005-01-01

    Nowadays, remote sensing imagery, especially with its high spatial resolution, has become an indispensable tool to provide timely up-gradation of urban land use and land cover information, which is a prerequisite for proper urban planning and management. The possible method described in the present paper to obtain urban land use types is based on the principle that land use can be derived from the land cover existing in a neighborhood. Here, moving window is used to represent the spatial pattern of land cover within a neighborhood and seven window sizes (61m×61 m,68m×68m, 75m×75m, 87m×87m, 99m×99m, 110m×110m and 121m×121m) are applied to determining the most proper window size. Then, the unsupervised method of ISODATA is employed to classify the layered land cover density maps obtained by the moving window. The results of accuracy evaluation show that the window size of 99m×99m is proper to infer urban land use categories and the proposed method has produced a land use map with a total accuracy of 85%.

  14. A comparison of ground and satellite observations of cloud cover to saturation pressure differences during a cold air outbreak

    Energy Technology Data Exchange (ETDEWEB)

    Alliss, R.J.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

    1996-04-01

    The role of clouds in the atmospheric general circulation and the global climate is twofold. First, clouds owe their origin to large-scale dynamical forcing, radiative cooling in the atmosphere, and turbulent transfer at the surface. In addition, they provide one of the most important mechanisms for the vertical redistribution of momentum and sensible and latent heat for the large scale, and they influence the coupling between the atmosphere and the surface as well as the radiative and dynamical-hydrological balance. In existing diagnostic cloudiness parameterization schemes, relative humidity is the most frequently used variable for estimating total cloud amount or stratiform cloud amount. However, the prediction of relative humidity in general circulation models (GCMs) is usually poor. Even for the most comprehensive GCMs, the predicted relative humidity may deviate greatly from that observed, as far as the frequency distribution of relative humidity is concerned. Recently, there has been an increased effort to improve the representation of clouds and cloud-radiation feedback in GCMs, but the verification of cloudiness parameterization schemes remains a severe problem because of the lack of observational data sets. In this study, saturation pressure differences (as opposed to relative humidity) and satellite-derived cloud heights and amounts are compared with ground determinations of cloud cover over the Gulf Stream Locale (GSL) during a cold air outbreak.

  15. Density-Dependent Effects of an Invasive Ant on a Ground-Dwelling Arthropod Community.

    Science.gov (United States)

    Cooling, M; Sim, D A; Lester, P J

    2015-02-01

    It is frequently assumed that an invasive species that is ecologically or economically damaging in one region, will typically be so in other environments. The Argentine ant Linepithema humile (Mayr) is listed among the world's worst invaders. It commonly displaces resident ant species where it occurs at high population densities, and may also reduce densities of other ground-dwelling arthropods. We investigated the effect of varying Argentine ant abundance on resident ant and nonant arthropod species richness and abundance in seven cities across its range in New Zealand. Pitfall traps were used to compare an invaded and uninvaded site in each city. Invaded sites were selected based on natural varying abundance of Argentine ant populations. Argentine ant density had a significant negative effect on epigaeic ant abundance and species richness, but hypogaeic ant abundance and species richness was unaffected. We observed a significant decrease in Diplopoda abundance with increasing Argentine ant abundance, while Coleoptera abundance increased. The effect on Amphipoda and Isopoda depended strongly on climate. The severity of the impact on negatively affected taxa was reduced in areas where Argentine ant densities were low. Surprisingly, Argentine ants had no effect on the abundance of the other arthropod taxa examined. Morphospecies richness for all nonant arthropod taxa was unaffected by Argentine ant abundance. Species that are established as invasive in one location therefore cannot be assumed to be invasive in other locations based on presence alone. Appropriate management decisions should reflect this knowledge. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Multiconfiguration Pair-Density Functional Theory Outperforms Kohn-Sham Density Functional Theory and Multireference Perturbation Theory for Ground-State and Excited-State Charge Transfer.

    Science.gov (United States)

    Ghosh, Soumen; Sonnenberger, Andrew L; Hoyer, Chad E; Truhlar, Donald G; Gagliardi, Laura

    2015-08-11

    The correct description of charge transfer in ground and excited states is very important for molecular interactions, photochemistry, electrochemistry, and charge transport, but it is very challenging for Kohn-Sham (KS) density functional theory (DFT). KS-DFT exchange-correlation functionals without nonlocal exchange fail to describe both ground- and excited-state charge transfer properly. We have recently proposed a theory called multiconfiguration pair-density functional theory (MC-PDFT), which is based on a combination of multiconfiguration wave function theory with a new type of density functional called an on-top density functional. Here we have used MC-PDFT to study challenging ground- and excited-state charge-transfer processes by using on-top density functionals obtained by translating KS exchange-correlation functionals. For ground-state charge transfer, MC-PDFT performs better than either the PBE exchange-correlation functional or CASPT2 wave function theory. For excited-state charge transfer, MC-PDFT (unlike KS-DFT) shows qualitatively correct behavior at long-range with great improvement in predicted excitation energies.

  17. Covariant energy density functionals: nuclear matter constraints and global ground state properties

    CERN Document Server

    Afanasjev, A V

    2016-01-01

    The correlations between global description of the ground state properties (binding energies, charge radii) and nuclear matter properties of the state-of-the-art covariant energy density functionals have been studied. It was concluded that the strict enforcement of the constraints on the nuclear matter properties (NMP) defined in Ref.\\ \\cite{RMF-nm} will not necessary lead to the functionals with good description of the binding energies and other ground and excited state properties. In addition, it will not substantially reduce the uncertainties in the predictions of the binding energies in neutron-rich systems. It turns out that the functionals, which come close to satisfying these NMP constraints, have some problems in the description of existing data. On the other hand, these problems are either absent or much smaller in the functionals which are carefully fitted to finite nuclei but which violate some NMP constraints. This is a consequence of the fact that the properties of finite nuclei are defined not o...

  18. Markedly divergent estimates of Amazon forest carbon density from ground plots and satellites

    Science.gov (United States)

    Mitchard, Edward T A; Feldpausch, Ted R; Brienen, Roel J W; Lopez-Gonzalez, Gabriela; Monteagudo, Abel; Baker, Timothy R; Lewis, Simon L; Lloyd, Jon; Quesada, Carlos A; Gloor, Manuel; ter Steege, Hans; Meir, Patrick; Alvarez, Esteban; Araujo-Murakami, Alejandro; Aragão, Luiz E O C; Arroyo, Luzmila; Aymard, Gerardo; Banki, Olaf; Bonal, Damien; Brown, Sandra; Brown, Foster I; Cerón, Carlos E; Chama Moscoso, Victor; Chave, Jerome; Comiskey, James A; Cornejo, Fernando; Corrales Medina, Massiel; Da Costa, Lola; Costa, Flavia R C; Di Fiore, Anthony; Domingues, Tomas F; Erwin, Terry L; Frederickson, Todd; Higuchi, Niro; Honorio Coronado, Euridice N; Killeen, Tim J; Laurance, William F; Levis, Carolina; Magnusson, William E; Marimon, Beatriz S; Marimon Junior, Ben Hur; Mendoza Polo, Irina; Mishra, Piyush; Nascimento, Marcelo T; Neill, David; Núñez Vargas, Mario P; Palacios, Walter A; Parada, Alexander; Pardo Molina, Guido; Peña-Claros, Marielos; Pitman, Nigel; Peres, Carlos A; Poorter, Lourens; Prieto, Adriana; Ramirez-Angulo, Hirma; Restrepo Correa, Zorayda; Roopsind, Anand; Roucoux, Katherine H; Rudas, Agustin; Salomão, Rafael P; Schietti, Juliana; Silveira, Marcos; de Souza, Priscila F; Steininger, Marc K; Stropp, Juliana; Terborgh, John; Thomas, Raquel; Toledo, Marisol; Torres-Lezama, Armando; van Andel, Tinde R; van der Heijden, Geertje M F; Vieira, Ima C G; Vieira, Simone; Vilanova-Torre, Emilio; Vos, Vincent A; Wang, Ophelia; Zartman, Charles E; Malhi, Yadvinder; Phillips, Oliver L

    2014-01-01

    Aim The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directly, and thus may miss significant spatial variations in forest structure. We test the stated accuracy of pantropical carbon maps using a large independent field dataset. Location Tropical forests of the Amazon basin. The permanent archive of the field plot data can be accessed at: http://dx.doi.org/10.5521/FORESTPLOTS.NET/2014_1 Methods Two recent pantropical RS maps of vegetation carbon are compared to a unique ground-plot dataset, involving tree measurements in 413 large inventory plots located in nine countries. The RS maps were compared directly to field plots, and kriging of the field data was used to allow area-based comparisons. Results The two RS carbon maps fail to capture the main gradient in Amazon forest carbon detected using 413 ground plots, from the densely wooded tall forests of the north-east, to the light-wooded, shorter forests of the south-west. The differences between plots and RS maps far exceed the uncertainties given in these studies, with whole regions over- or under-estimated by > 25%, whereas regional uncertainties for the maps were reported to be < 5%. Main conclusions Pantropical biomass maps are widely used by governments and by projects aiming to reduce deforestation using carbon offsets, but may have significant regional biases. Carbon-mapping techniques must be revised to account for the known ecological variation in tree wood density and allometry to create maps suitable for carbon accounting. The use of single relationships between tree canopy height and above-ground biomass inevitably yields large, spatially correlated errors. This presents a significant challenge to both the forest conservation and remote sensing communities

  19. Effects of post-fire salvage logging and a skid trail treatment on ground cover, soils, and sediment production in the interior western United States

    Science.gov (United States)

    Joseph W. Wagenbrenner; Lee H. MacDonald; Robert N. Coats; Peter R. Robichaud; Robert E. Brown

    2015-01-01

    Post-fire salvage logging adds another set of environmental effects to recently burned areas, and previous studies have reported varying impacts on vegetation, soil disturbance, and sediment production with limited data on the underlying processes. Our objectives were to determine how: (1) ground-based post-fire logging affects surface cover, soil water repellency,...

  20. Ground Operations of the ISS GNC Babb-Mueller Atmospheric Density Model

    Science.gov (United States)

    Brogan, Jonathan

    2002-01-01

    The ISS GNC system was updated recently with a new software release that provides onboard state determination capability. Prior to this release, only the Russian segment maintained and propagated the onboard state, which was periodically updated through Russian ground tracking. The new software gives the US segment the capability for maintaining the onboard state, and includes new GPS and state vector propagation capabilities. Part of this software package is an atmospheric density model based on the Babb-Mueller algorithm. Babb-Mueller efficiently mimics a full analytical density model, such as the Jacchia model. While lacchia is very robust and is used in the Mission Control Center, it is too computationally intensive for use onboard. Thus, Babb-Mueller was chosen as an alternative. The onboard model depends on a set of calibration coefficients that produce a curve fit to the lacchia model. The ISS GNC system only maintains one set of coefficients onboard, so a new set must be uplinked by controllers when the atmospheric conditions change. The onboard density model provides a real-time density value, which is used to calculate the drag experienced by the ISS. This drag value is then incorporated into the onboard propagation of the state vector. The propagation of the state vector, and therefore operation of the BabbMueller algorithm, will be most critical when GPS updates and secondary state vector sources fail. When GPS is active, the onboard state vector will be updated every ten seconds, so the propagation error is irrelevant. When GPS is inactive, the state vector must be updated at least every 24 hours, based on current protocol. Therefore, the Babb-Mueller coefficients must be accurate enough to fulfill the state vector accuracy requirements for at least one day. A ground operations concept was needed in order to manage both the on board Babb-Mueller density model and the onboard state quality. The Babb-Mueller coefficients can be determined operationally

  1. Intensity of Ground Cover Crop Arachis pintoi, Rhizobium Inoculation and Phosphorus Application and Their Effects on Field Growth and Nutrient Status of Cocoa Plants

    Directory of Open Access Journals (Sweden)

    John Bako Baon

    2006-08-01

    Full Text Available Arachis pintoiis potentially as a cover crop for cocoa (Theobroma cacaoL. farm, however information regarding its effect on the growth of cocoa plants in the field is very limited. The objective of this experiment is to investigate the combined influence of ground cover crop A. pintoi, rhizobial bacterial inoculation and phosphorus (P fertilizer on the growth of cocoa in the field and nutrient status. This experiment laid out in split-split plot design consisted of three levels of cover crop (without, A. pintoiand Calopogonium caeruleum, two levels of rhizobium inoculation (not inoculated and inoculated and two levels of phosphorus application (no P added and P added. The results showed that in field condition the presence of A. pintoias cover crop did not affect the growth of cocoa. On the other hand, C. caeruleumas cover crop tended to restrict cocoa growth compared to A. pintoi. Application of P increased leaf number of cocoa plant. Biomass production of A. pintoiwas 40% higher than C. caeruleum. Soil organic carbon and nitrogen contents were not affected by ground cover crops, though higher value (0.235% N and 1.63% organic C was obtained from combined treatments of inoculation and P addition or neither inoculation nor P addition. In the case of no rhizobium inoculation, soil N content in cocoa farm with A. pintoicover crop was lower than that of without cover crop or with C. caeruleum. Cover crop increased plant N content when there was no inoculation, on the other hand rhizobium inoculation decreased N content of cocoa tissue. Tissue P content of cocoa plant was not influenced by A. Pintoicover crop or by rhizobium inoculation, except that the P tissue content of cocoa was 28% higher when the cover crop was C. caeruleumand inoculated. Key words : Arachis pintoi, Theobroma cacao, Calopogonium caeruleum, rhizobium, nitrogen, phosphorus.

  2. Epiphyte-cover on seagrass (Zostera marina L. leaves impedes plant performance and radial O2 loss from the below-ground tissue

    Directory of Open Access Journals (Sweden)

    Kasper Elgetti Brodersen

    2015-08-01

    Full Text Available The O2 budget of seagrasses is a complex interaction between several sources and sinks, which is strongly regulated by light availability and mass transfer over the diffusive boundary layer (DBL surrounding the plant. Epiphyte growth on leaves may thus strongly affect the O2 availability of the seagrass plant and its capability to aerate its rhizosphere as a defence against plant toxins.We used electrochemical and fiber-optic microsensors to quantify the O2 flux, DBL and light microclimate around leaves with and without filamentous algal epiphytes. We also quantified the below-ground radial O2 loss from roots (~1 mm from the root-apex to elucidate how this below-ground oxic microzone was affected by the presence of epiphytes.Epiphyte-cover on seagrass leaves (~21% areal cover resulted in reduced light quality and quantity for photosynthesis, thus leading to reduced plant fitness. A ~4 times thicker diffusive boundary layer around leaves with epiphyte-cover impeded gas (and nutrient exchange with the surrounding water-column and thus the amount of O2 passively diffusing into the leaves in darkness. During light exposure of the leaves, radial oxygen loss from the below-ground tissue was ~2 times higher from plants without epiphyte-cover. In contrast, no O2 was detectable at the surface of the root-cap tissue of plants with epiphyte-cover during darkness, leaving the plants more susceptible to sulphide intrusion.Epiphyte growth on seagrass leaves thus negatively affects the light climate and O2 uptake in darkness, hampering the plants performance and thereby reducing the oxidation capability of its below-ground tissue.

  3. Geostatistical Analysis of Population Density and the Change of Land Cover and Land Use in the Komadugu-Yobe River Basin in Nigeria

    Science.gov (United States)

    Tobar, I.; Lee, J.; Black, F. W.; Babamaaji, R. A.

    2014-12-01

    The Komadugu-Yobe River Basin in northeastern Nigeria is an important tributary of Lake Chad and has experienced significant changes in population density and land cover in recent decades. The present study focuses on the application of geostatistical methods to examine the land cover and population density dynamics in the river basin. The geostatistical methods include spatial autocorrelation, overlapping neighborhood statistics with Pearson's correlation coefficient, Moran's I index analysis, and indicator variogram analysis with rose diagram. The land cover and land use maps were constructed from USGS Landsat images and Globcover images from the European Space Agency. The target years of the analysis are 1970, 1986, 2000, 2005, and 2009. The calculation of net changes in land cover indicates significant variation in the changes of rainfed cropland, mosaic cropland, and grassland. Spatial autocorrelation analysis and Moran I index analysis showed that the distribution of land cover is highly clustered. A new GIS geostatistical tool was designed to calculate the overlapping neighborhood statistics with Pearson's correlation coefficient between the land use/land cover and population density datasets. The 10x10 neighborhood cell unit showed a clear correlation between the variables in certain zones of the study area. The ranges calculated from the indicator variograms of land use and land cover and population density showed that the cropland and sparse vegetation are most closely related to the spatial change of population density.

  4. Phytoseiidae (Acari: Mesostigmata) within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants.

    Science.gov (United States)

    Childers, Carl C; Denmark, Harold A

    2011-08-01

    Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the family Phytoseiidae (Acari: Mesostigmata) in central and south central Florida. Inner and outer canopy leaves, open flowers, fruit, twigs, and trunk scrapings were sampled monthly between September 1994 and January 1996. Vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards. The two remaining orchards were on full herbicide programs and ground cover plants were absent. Thirty-three species of phytoseiid mites were identified from 35,405 specimens collected within citrus tree canopies within the seven citrus orchards, and 8,779 specimens from vines and ground cover plants within five of the seven orchards. The six most abundant phytoseiid species found within citrus tree canopies were: Euseius mesembrinus (Dean) (20,948), Typhlodromalus peregrinus (Muma) (8,628), Iphiseiodes quadripilis (Banks) (2,632), Typhlodromips dentilis (De Leon) (592), Typhlodromina subtropica Muma and Denmark (519), and Galendromus helveolus (Chant) (315). The six most abundant species found on vines or ground cover plants were: T. peregrinus (6,608), E. mesembrinus (788), T. dentilis (451), I. quadripilis (203), T. subtropica (90), and Proprioseiopsis asetus (Chant) (48). The remaining phytoseiids included: Amblyseius aerialis (Muma), A. herbicolus (Chant), A. largoensis (Chant), A. multidentatus (Chant), A. sp. near multidentatus, A. obtusus (Koch), Chelaseius vicinus (Muma), Euseius hibisci Chant, Galendromus gratus (Chant), Metaseiulus mcgregori (Chant), Neoseiulus mumai (Denmark), N. vagus (Denmark), Phytoscutus sexpilis (Muma), Phytoseiulus macropilis (Banks), Proprioseiopsis detritus (Muma), P. dorsatus (Muma), P. macrosetae (Banks), P. rotundus (Muma), P. solens (De Leon), Typhlodromips deleoni (Muma), T. dillus (De Leon), T. dimidiatus (De Leon), T. mastus Denmark and Muma, T. simplicissimus (De Leon), and T. sp

  5. Recreational Trails Reduce the Density of Ground-Dwelling Birds in Protected Areas

    Science.gov (United States)

    Thompson, Bill

    2015-05-01

    Recreational disturbance associated with trails has been identified as one of the major factors causing a decline of native biodiversity within protected areas. However, despite the negative impacts that recreation can have on biodiversity, providing public access to nature is critical for the future of the conservation of biodiversity. As such, many protected area managers are looking for tools to help maintain a balance between public access and biodiversity conservation. The objectives of this study were to examine the impacts of recreational trails on forest-dwelling bird communities in eastern North America, identify functional guilds which are particularly sensitive to recreational trails, and derive guidelines for trail design to assist in managing the impacts of recreational trails on forest-dwelling birds. Trails within 24 publicly owned natural areas were mapped, and breeding bird communities were described with the use of point count surveys. The density of forest birds, particularly of those species which nest or forage on the ground, were significantly positively influenced by the amount of trail-free refuge habitat. Although management options to control trail use in non-staffed protected areas are limited, this study suggests that protected area managers could design and maintain a trail network that would minimize impacts on resident wildlife, while providing recreational opportunities for visitors, by designing their trail network to maximize the area of trail-free habitat.

  6. Influence of landscape heterogeneity on spatial patterns of wood productivity, wood specific density and above ground biomass in Amazonia

    Directory of Open Access Journals (Sweden)

    L. O. Anderson

    2009-09-01

    Full Text Available Long-term studies using the RAINFOR network of forest plots have generated significant insights into the spatial and temporal dynamics of forest carbon cycling in Amazonia. In this work, we map and explore the landscape context of several major RAINFOR plot clusters using Landsat ETM+ satellite data. In particular, we explore how representative the plots are of their landscape context, and test whether bias in plot location within landscapes may be influencing the regional mean values obtained for important forest biophysical parameters. Specifically, we evaluate whether the regional variations in wood productivity, wood specific density and above ground biomass derived from the RAINFOR network could be driven by systematic and unintentional biases in plot location. Remote sensing data covering 45 field plots were aggregated to generate landscape maps to identify the specific physiognomy of the plots. In the Landsat ETM+ data, it was possible to spectrally differentiate three types of terra firme forest, three types of forests over Paleovarzea geomorphologycal formation, two types of bamboo-dominated forest, palm forest, Heliconia monodominant vegetation, swamp forest, disturbed forests and land use areas. Overall, the plots were generally representative of the forest physiognomies in the landscape in which they are located. Furthermore, the analysis supports the observed regional trends in those important forest parameters. This study demonstrates the utility of landscape scale analysis of forest physiognomies for validating and supporting the finds of plot based studies. Moreover, the more precise geolocation of many key RAINFOR plot clusters achieved during this research provides important contextual information for studies employing the RAINFOR database.

  7. Influence of landscape heterogeneity on spatial patterns of wood productivity, wood specific density and above ground biomass in Amazonia

    Science.gov (United States)

    Anderson, L. O.; Malhi, Y.; Ladle, R. J.; Aragão, L. E. O. C.; Shimabukuro, Y.; Phillips, O. L.; Baker, T.; Costa, A. C. L.; Espejo, J. S.; Higuchi, N.; Laurance, W. F.; López-González, G.; Monteagudo, A.; Núñez-Vargas, P.; Peacock, J.; Quesada, C. A.; Almeida, S.

    2009-09-01

    Long-term studies using the RAINFOR network of forest plots have generated significant insights into the spatial and temporal dynamics of forest carbon cycling in Amazonia. In this work, we map and explore the landscape context of several major RAINFOR plot clusters using Landsat ETM+ satellite data. In particular, we explore how representative the plots are of their landscape context, and test whether bias in plot location within landscapes may be influencing the regional mean values obtained for important forest biophysical parameters. Specifically, we evaluate whether the regional variations in wood productivity, wood specific density and above ground biomass derived from the RAINFOR network could be driven by systematic and unintentional biases in plot location. Remote sensing data covering 45 field plots were aggregated to generate landscape maps to identify the specific physiognomy of the plots. In the Landsat ETM+ data, it was possible to spectrally differentiate three types of terra firme forest, three types of forests over Paleovarzea geomorphologycal formation, two types of bamboo-dominated forest, palm forest, Heliconia monodominant vegetation, swamp forest, disturbed forests and land use areas. Overall, the plots were generally representative of the forest physiognomies in the landscape in which they are located. Furthermore, the analysis supports the observed regional trends in those important forest parameters. This study demonstrates the utility of landscape scale analysis of forest physiognomies for validating and supporting the finds of plot based studies. Moreover, the more precise geolocation of many key RAINFOR plot clusters achieved during this research provides important contextual information for studies employing the RAINFOR database.

  8. Influence of landscape heterogeneity on spatial patterns of wood productivity, wood specific density and above ground biomass in Amazonia

    Directory of Open Access Journals (Sweden)

    L. O. Anderson

    2009-02-01

    Full Text Available Long-term studies using the RAINFOR network of forest plots have generated significant insights into the spatial and temporal dynamics of forest carbon cycling in Amazonia. In this work, we map and explore the landscape context of several major RAINFOR plot clusters using Landsat ETM+ satellite data. In particular, we explore how representative the plots are of their landscape context, and test whether bias in plot location within landscapes may be influencing the regional mean values obtained for important forest biophysical parameters. Specifically, we evaluate whether the regional variations in wood productivity, wood specific density and above ground biomass derived from the RAINFOR network could be driven by systematic and unintentional biases in plot location. Remote sensing data covering 45 field plots were aggregated to generate landscape maps to identify the specific physiognomy of the plots. In the Landsat ETM+ data, it was possible to spectrally differentiate three types of terra firme forest, three types of alluvial terrain forest, two types of bamboo-dominated forest, palm forest, Heliconia monodominant vegetation, swamp forest, disturbed forests and land use areas. Overall, the plots were generally representative of the forest physiognomies in the landscape in which they are located. Furthermore, the analysis supports the observed regional trends in those important forest parameters. This study demonstrates the utility of landscape scale analysis of forest physiognomies for validating and supporting the finds of plot based studies. Moreover, the more precise geolocation of many key RAINFOR plot clusters achieved during this research provides important contextual information for studies employing the RAINFOR database.

  9. On the growth of Penaeus indicus experimented in cages at different densities in a selected nursery ground

    Digital Repository Service at National Institute of Oceanography (India)

    Aravindakshan, P.N; Paulinose, V.T.; Balasubramanian, T.; Menon, P.G.; Kutty, M.K.

    Effect of different densities on the growth of Penaeus indicus was studied in a higly productive nursery ground located at Ramanthuruth Island (lat. 9~'58'50"N, long. 76~'15'40"E) using cages. Eight cages of the same size were placed with prawns...

  10. The landscape configuration of zoonotic transmission of Ebola virus disease in West and Central Africa: interaction between population density and vegetation cover.

    Science.gov (United States)

    Walsh, Michael G; Haseeb, Ma

    2015-01-01

    Ebola virus disease (EVD) is an emerging infectious disease of zoonotic origin that has been responsible for high mortality and significant social disruption in West and Central Africa. Zoonotic transmission of EVD requires contact between susceptible human hosts and the reservoir species for Ebolaviruses, which are believed to be fruit bats. Nevertheless, features of the landscape that may facilitate such points of contact have not yet been adequately identified. Nor have spatial dependencies between zoonotic EVD transmission and landscape structures been delineated. This investigation sought to describe the spatial relationship between zoonotic EVD transmission events, or spillovers, and population density and vegetation cover. An inhomogeneous Poisson process model was fitted to all precisely geolocated zoonotic transmissions of EVD in West and Central Africa. Population density was strongly associated with spillover; however, there was significant interaction between population density and green vegetation cover. In areas of very low population density, increasing vegetation cover was associated with a decrease in risk of zoonotic transmission, but as population density increased in a given area, increasing vegetation cover was associated with increased risk of zoonotic transmission. This study showed that the spatial dependencies of Ebolavirus spillover were associated with the distribution of population density and vegetation cover in the landscape, even after controlling for climate and altitude. While this is an observational study, and thus precludes direct causal inference, the findings do highlight areas that may be at risk for zoonotic EVD transmission based on the spatial configuration of important features of the landscape.

  11. The landscape configuration of zoonotic transmission of Ebola virus disease in West and Central Africa: interaction between population density and vegetation cover

    Directory of Open Access Journals (Sweden)

    Michael G. Walsh

    2015-01-01

    Full Text Available Ebola virus disease (EVD is an emerging infectious disease of zoonotic origin that has been responsible for high mortality and significant social disruption in West and Central Africa. Zoonotic transmission of EVD requires contact between susceptible human hosts and the reservoir species for Ebolaviruses, which are believed to be fruit bats. Nevertheless, features of the landscape that may facilitate such points of contact have not yet been adequately identified. Nor have spatial dependencies between zoonotic EVD transmission and landscape structures been delineated. This investigation sought to describe the spatial relationship between zoonotic EVD transmission events, or spillovers, and population density and vegetation cover. An inhomogeneous Poisson process model was fitted to all precisely geolocated zoonotic transmissions of EVD in West and Central Africa. Population density was strongly associated with spillover; however, there was significant interaction between population density and green vegetation cover. In areas of very low population density, increasing vegetation cover was associated with a decrease in risk of zoonotic transmission, but as population density increased in a given area, increasing vegetation cover was associated with increased risk of zoonotic transmission. This study showed that the spatial dependencies of Ebolavirus spillover were associated with the distribution of population density and vegetation cover in the landscape, even after controlling for climate and altitude. While this is an observational study, and thus precludes direct causal inference, the findings do highlight areas that may be at risk for zoonotic EVD transmission based on the spatial configuration of important features of the landscape.

  12. STRUCTURE AND CHARACTERISTICS OF TI-AL-NI SYSTEM COVERING, APPLIED ON THE STEEL GROUND USING ELECTRON-BEAM HEATING

    Directory of Open Access Journals (Sweden)

    I. V. Murashova

    2011-01-01

    Full Text Available The morphology of the system Ti-Al-Ni covering, received by means of self-distributing high-temperature synthesis, initiated by electron-beam heating, on the basis of steel St3 is investigated.

  13. Trends of six month nighttime ground-based cloud cover values over Manila Observatory (14.64N, 121.07E)

    Science.gov (United States)

    Gacal, G. F. B.; Lagrosas, N.

    2016-12-01

    The ground reflects thermal radiation during nighttime. Clouds reflect this radiation to the ground and cause increase in ambient temperature. In this study, trends of nighttime cloud cover are analyzed using a commercial camera (Canon Powershot A2300) that is operated continuously to capture images of clouds at 5 minute interval. The camera is situated inside a rain-proof box with a glass oculus and is placed on the rooftop of the Manila Observatory building. To detect pixels with clouds, the pictures are converted from its native JPEG format to grayscale format. The pixels are then screened for clouds by looking at the values of pixels with and without clouds. In grayscale format, pixels with clouds have greater pixel values than pixels without clouds. Based on the observations, a threshold pixel value of 17 is employed to discern pixels with clouds from pixels without clouds. When moon is present in the image, the grayscale image, which is in 8-bit unsigned integer format, is converted into double format. The moon signals are modelled using a two dimensional Gaussian function and is subtracted from the converted image (Gacal et al, 2016). This effectively removes the moon signals but preserves the cloud signals. This method is applied to the data collected from the months of January, February, March, October, November and December 2015. In Manila, dry months are from November to April. Wet months are from May to October. The trends of nighttime cloud cover values over Manila Observatory are shown in the figure below. Frequency distribution of cloud cover values of the first and last three months of the year show that dry and wet months have higher and lower frequency of low cloud cover values, respectively. The trend also exhibits a decrease of cloud cover from October to December but increases back from January until March. This is exhibited in the decrease in the frequency of cloud cover values in the 20%-100% range from October to December. This can be

  14. Eupalopsellidae and Stigmaeidae (Acari: Prostigmata) within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines, and ground cover plants.

    Science.gov (United States)

    Childers, Carl C; Ueckermann, Eduard A

    2014-10-01

    Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the families Eupalopsellidae and Stigmaeidae (Acari: Prostigmata) in central and south central Florida. Inner and outer canopy leaves, fruit, twigs, and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. Two species of eupalopsellid mites (Exothorhis caudata Summers and Saniosulus harteni (van-Dis and Ueckermann)) were identified from 252 specimens collected within citrus tree canopies within the seven citrus orchards of which 249 were E. caudata. Only two E. caudata were collected from ground cover plants within five of the seven orchards. Eight species of Stigmaeidae were identified from 5,637 specimens: Agistemus floridanus Gonzalez, A. terminalis Gonzalez, Eustigmaeus arcuata (Chandhri), E. sp. near arcuata, E. segnis (Koch), Mediostigmaeus citri (Rakha and McCoy), Stigmaeus seminudus Wood, and Zetzellia languida Gonzalez were collected from within citrus tree canopies from seven orchard sites. Agistemus floridanus was the only species in either family that was abundant with 5,483 collected from within citrus tree canopies compared with only 39 from vine or ground cover plants. A total of 431 samples from one or more of 82 vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards and one or more eupalopsellids or stigmaeids were collected from 19 of these plants. Richardia brasiliensis (Meg.) Gomez had nine A. floridanus from 5 of 25 samples collected from this plant. Solanum sp. had five A. floridanus from three samples taken. Both eupalopsellid and stigmaeid species numbers represented orchards were on full herbicide programs and ground cover plants were absent. Agistemus floridanus was more abundant in the citrus orchards with on-going or recent herbicide programs compared with orchards having well-developed ground

  15. Short-term priority over exotic annuals increases the initial density and longer-term cover of native perennial grasses.

    Science.gov (United States)

    Vaughni, Kurt J; Young, Truman P

    2015-04-01

    Temporal priority can affect individual performance and reproduction, as well as community assembly, but whether these effects persist over time remains unclear, and their demographic mechanisms have been little explored. The continued dominance of exotic annual grasses in California has been commonly attributed to their demonstrated early germination and rapid early growth relative to native perennial grasses. This advantage may play a crucial role in the structure of California exotic annual grasslands, as well as in the practice of native grassland restoration. We tested whether a two-week planting advantage under field conditions increased individual survival, growth, and reproduction for four native perennial grass species and whether these effects persisted over three years. We show that short-term priority significantly increased the establishment success of' native perennial grasses. Increased density of native grass seedlings presaged later large increases in cover that were not evident in the first year after planting. Although priority effects at the individual level may diminish over time, short differences in emergence timing can have long-lasting effects on community structure. Earlier germination and faster initial growth of exotic annual species may help explain their unprecedented invasion and continued dominance of California grasslands. Finally, these results highlight the importance of priority effects for effective exotic annual control during native grassland restoration in California: initial control can increase the establishment of native perennial seedlings, which then results in long-term control by mature native individuals.

  16. Density Functional Investigation of the Adsorption of Isooctane, Ethanol, and Acetic Acid on a Water-Covered Fe(100) Surface.

    Science.gov (United States)

    Bedolla, Pedro O; Feldbauer, Gregor; Wolloch, Michael; Gruber, Christoph; Eder, Stefan J; Dörr, Nicole; Mohn, Peter; Redinger, Josef; Vernes, András

    2014-09-18

    The presence of water in biofuels poses the question of how it affects the frictional performance of additives in fuels containing organic substances. To investigate the effect of water on the adsorption of molecules present in fuel and its additives we simulated within the framework of density functional theory the adsorption of ethanol, isooctane (2,2,4-trimethylpentane), and acetic acid on a bare and a water-covered Fe(100) surface. Van der Waals interactions are taken into account in our computations. In those molecules, where dispersion forces contribute significantly to the binding mechanism, the water layer has a stronger screening effect. Additionally, this effect can be enhanced by the presence of polar functional groups in the molecule. Thus, with the introduction of a water layer, the adsorption energy of isooctane and ethanol is reduced but it is increased in the case of the acetic acid. The adsorption configuration of ethanol is changed, while the one of acetic acid is moderately, and for isooctane only very slightly altered. Therefore, the effect of a water layer in the adsorption of organic molecules on an Fe(100) surface strongly depends on the type of bond and consequently, so do the tribological properties.

  17. Effect of Polythene-covering on Above-ground tuberization and storage roots yield in Cassava (Manihot esculenta Crantz

    Directory of Open Access Journals (Sweden)

    Abdullahi N

    2014-02-01

    Full Text Available Present study aimed to investigate the effectiveness of polythene-covering on activation of dormant auxiliary buds on the stem for lateral tuber formation and the resultant effect on total storage roots yield. Three time intervals i.e. 1 day after planting, 30 days after planting and 60 days after planting used as treatment, and uncovered stem used as control. Treatments were tested in randomized complete block design with three replications. Regardless of the variety, stem polythene-covering at day 1 after planting showed the highest effect with respect to storage roots production and yield components tested. However, the effect of stem polythene-covering at day 1 after planting in terms of dry mass partitioning to storage roots was the lowest across all the treatments (25.50 to 27.37% of the biomass compared to that of stem covering at day 60 after planting (33.10 to 37.20%. This study opens new perspectives in cassava yield improvement which hitherto has not been exploited.

  18. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    KAUST Repository

    Jadoon, Khan

    2015-09-18

    We tested an off-ground ground-penetrating radar (GPR) system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  19. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Khan Zaib Jadoon

    2015-09-01

    Full Text Available We tested an off-ground ground-penetrating radar (GPR system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  20. Assessing the thermal dissipation sap flux density method for monitoring cold season water transport in seasonally snow-covered forests.

    Science.gov (United States)

    Chan, Allison M; Bowling, David R; Phillips, Nathan

    2017-07-01

    Productivity of conifers in seasonally snow-covered forests is high before and during snowmelt when environmental conditions are optimal for photosynthesis. Climate change is altering the timing of spring in many locations, and changes in the date of transition from winter dormancy can have large impacts on annual productivity. Sap flow methods provide a promising approach to monitor tree activity during the cold season and the winter-spring and fall-winter transitions. Although sap flow techniques have been widely used, cold season results are generally not reported. Here we examine the feasibility of using the Granier thermal dissipation (TD) sap flux density method to monitor transpiration and dormancy of evergreen conifers during the cold season. We conducted a laboratory experiment which demonstrated that the TD method reliably detects xylem water transport (when it occurs) both at near freezing temperature and at low flow rate, and that the sensors can withstand repeated freeze-thaw events. However, the dependence between sensor output and water transport rate in these experiments differed from the established TD relation. In field experiments, sensors installed in two Abies forests lasted through two winters and a summer with low failure. The baseline (no-flow) sensor output varied considerably with temperature during the cold season, and a new baseline algorithm was developed to accommodate this variation. The Abies forests differed in elevation (2070 and 2620 m), and there was a clear difference in timing of initiation and cessation of transpiration between them. We conclude that the TD method can be reliably used to examine water transport during cold periods with associated low flow conditions. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Relativistic time-dependent density functional theory, a study of the ground and excited states of the zinc dimer

    Energy Technology Data Exchange (ETDEWEB)

    Kullie, Ossama [CNRS et Universite de Strasbourg, Institut de Chimie, Laboratoire de Chimie Quantique, 1 Rue Blaise Pascal, F- 67008 Strasbourg cedex (France)

    2012-07-01

    In this poster I present a (time-dependent) density functional study of the 20 low-lying excited states as well the ground states of the zinc dimer Zn{sub 2}. I analyze the spectrum of the dimer obtained form all electrons calculations which are performed using time-depended density functional with a relativistic 4-components-, and spin-free-Hamiltonian. I show results for different well-known density functional approximations, in comparing with literature and experimental values, the results are very encouraging, especially for the lowest excited states of these dimers. However, the results show that only the long-range corrected functionals such CAMB3LYP gives the correct asymptotic behavior for the higher states, for which the best result is obtained, and a comparable result is obtained from PBE0 functional.

  2. Study of growth and development features of ten ground cover plants in Kish Island green space in warm season

    Directory of Open Access Journals (Sweden)

    S. Shooshtarian

    2016-05-01

    Full Text Available Having special ecological condition, Kish Island has a restricted range of native species of ornamental plants. Expansion of urban green space in this Island is great of importance due to its outstanding touristy position in the South of Iran. The purpose of this study was to investigate the growth and development of groundcover plants planted in four different regions of Kish Island and to recommend the most suitable and adaptable species for each region. Ten groundcover species included Festuca ovina L., Glaucium flavum Crantz., Frankenia thymifolia Desf., Sedum spurium Bieb., Sedum acre L., .Potentilla verna L., Carpobrotus acinaciformis (L. L. Bolus., Achillea millefolium L., Alternanthera dentata Moench. and Lampranthus spectabilis Haw. Evaluation of growth and development had been made by measurement of morphological characteristics such as height, covering area, leaf number and area, dry and fresh total weights and visual scoring. Physiological traits included proline and chlorophyll contents evaluated. This study was designed in factorial layout based on completely randomized blocks design with six replicates. Results showed that in terms of indices such as covering area, visual quality, height, total weight, and chlorophyll content, Pavioon and Sadaf plants had the most and the worst performances, respectively in comparison to other regions’ plants. Based on evaluated characteristics, C. acinaciformis, L. spectabilis and F. thymifolia had the most expansion and growth in all quadruplet regions and are recommend for planting in Kish Island and similar climates.

  3. An ecology of prestige in New York City: Examining the relationships among population density, socio-economic status, group identity, and residential canopy cover

    Science.gov (United States)

    J. Morgan Grove; Dexter H. Locke; Jarlath P.M. O' Neil-Dunne

    2014-01-01

    Several social theories have been proposed to explain the uneven distribution of vegetation in urban residential areas: population density, social stratification, luxury effect, and ecology of prestige. We evaluate these theories using a combination of demographic and socio-economic predictors of vegetative cover on all residential lands in New York City. We use...

  4. Investigating Hydrogeologic Controls on Sandhill Wetlands in Covered Karst with 2D Resistivity and Ground Penetrating Radar

    Science.gov (United States)

    Downs, C. M.; Nowicki, R. S.; Rains, M. C.; Kruse, S.

    2015-12-01

    In west-central Florida, wetland and lake distribution is strongly controlled by karst landforms. Sandhill wetlands and lakes are sand-filled upland basins whose water levels are groundwater driven. Lake dimensions only reach wetland edges during extreme precipitation events. Current wetland classification schemes are inappropriate for identifying sandhill wetlands due to their unique hydrologic regime and ecologic expression. As a result, it is difficult to determine whether or not a wetland is impacted by groundwater pumping, development, and climate change. A better understanding of subsurface structures and how they control the hydrologic regime is necessary for development of an identification and monitoring protocol. Long-term studies record vegetation diversity and distribution, shallow ground water levels and surface water levels. The overall goals are to determine the hydrologic controls (groundwater, seepage, surface water inputs). Most recently a series of geophysical surveys was conducted at select sites in Hernando and Pasco County, Florida. Electrical resistivity and ground penetrating radar were employed to image sand-filled basins and the top of the limestone bedrock and stratigraphy of wetland slopes, respectively. The deepest extent of these sand-filled basins is generally reflected in topography as shallow depressions. Resistivity along inundated wetlands suggests the pools are surface expressions of the surficial aquifer. However, possible breaches in confining clay layers beneath topographic highs between depressions are seen in resistivity profiles as conductive anomalies and in GPR as interruptions in otherwise continuous horizons. These data occur at sites where unconfined and confined water levels are in agreement, suggesting communication between shallow and deep groundwater. Wetland plants are observed outside the historic wetland boundary at many sites, GPR profiles show near-surface layers dipping towards the wetlands at a shallower

  5. Effects of exchange-correlation potentials in density functional descriptions of ground-state and photoionization of fullerenes

    Science.gov (United States)

    Choi, Jinwoo; Chang, Eonho; Anstine, Dylan M.; Chakraborty, Himadri

    2016-05-01

    We study the ground state properties of C60 and C240 molecules in a spherical frame of local density approximation (LDA). Within this mean-field theory, two different approximations to the exchange-correlation (xc) functional are used: (i) The Gunnerson-Lundqvist parametrization augmented by a treatment to correct for the electron self-interaction and (ii) the van Leeuwen and Baerends (LB94) model potential that inclusively restores electron's asymptotic properties. Results show differences in the ground-state potential, level energies and electron densities between the two xc choices. We then use the ground structure to find the excited and ionized states of the systems and calculate dipole single-photoionization cross sections in a time-dependent LDA method that incorporates linear-response dynamical correlations. Comparative effects of the choices of xc on collective plasmon and single-excitation Auger resonances as well as on geometry driven cavity oscillations are found significant. The work is supported by the NSF, USA.

  6. Land Use and Land Cover, Existing land use derived from orthoimagery. Ground-truthing from discussion with local plan commission members., Published in 2000, 1:12000 (1in=1000ft) scale, Portage County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Land Use and Land Cover dataset current as of 2000. Existing land use derived from orthoimagery. Ground-truthing from discussion with local plan commission members..

  7. Crop cover the principal influence on non-crop ground beetle (Coleoptera, Carabidae) activity and assemblages at the farm scale in a long-term assessment.

    Science.gov (United States)

    Eyre, M D; Sanderson, R A; McMillan, S D; Critchley, C N R

    2016-04-01

    Ground beetle data were generated using pitfall traps in the 17-year period from 1993 to 2009 and used to investigate the effects of changes in surrounding crop cover on beetle activity and assemblages, together with the effects of weather variability. Beetles were recorded from non-crop field margins (overgrown hedges). Crop cover changes explained far more variation in the beetle assemblages recorded than did temperature and rainfall variation. A reduction in management intensity and disturbance in the crops surrounding the traps, especially the introduction and development of willow coppice, was concomitant with changes in individual species activity and assemblage composition of beetles trapped in non-crop habitat. There were no consistent patterns in either overall beetle activity or in the number of species recorded over the 17-year period, but there was a clear change from assemblages dominated by smaller species with higher dispersal capability to ones with larger beetles with less dispersal potential and a preference for less disturbed agroecosystems. The influence of surrounding crops on ground beetle activity in non-crop habitat has implications for ecosystem service provision by ground beetles as pest predators. These results are contrary to conventional assumptions and interpretations, which suggest activity of pest predators in crops is influenced primarily by adjacent non-crop habitat. The long-term nature of the assessment was important in elucidation of patterns and trends, and indicated that policies such as agri-environment schemes should take cropping patterns into account when promoting management options that are intended to enhance natural pest control.

  8. [Pediatric cases in preclinical emergency medicine: critical aspects in the range of missions covered by ground ambulance and air rescue services].

    Science.gov (United States)

    Schlechtriemen, T; Masson, R; Burghofer, K; Lackner, C K; Altemeyer, K H

    2006-03-01

    The aim of this study was to demonstrate differences in structure and severity of pediatric emergencies treated by aeromedical (air rescue) or ground ambulances services. Conclusions for the training of emergency physicians are discussed. In a 3-year study period, a total of 9,274 pediatric emergencies covered by the ADAC air rescue service are compared to 4,344 pediatric patients of ground ambulance services in Saarland. In aeromedical services pediatric emergencies are more frequent (12.9% vs. 6.4%), trauma predominates (59.9% vs. 35.6%) and severe injuries or diseases occur more frequently (30.5% vs. 15.0%). In both groups pediatric emergency cases are concentrated into very few diagnostic groups: more than one third of the cases involving pre-school children is due to convulsions. Respiratory diseases and intoxication are the next most frequent causes and are more common in ground ambulance patients. Head trauma is the most common diagnosis in cases of pediatric trauma, followed by musculoskeletal and thoracoabdominal trauma. All types of severe trauma are more frequent in pediatric patients of the aeromedical services. Training of emergency physicians should include pediatric life support and specific information about frequent pediatric emergency situations. For emergency physicians in aeromedical services, an intensive training in pediatric trauma life support is also necessary.

  9. Classical probability density distributions with uncertainty relations for ground states of simple non-relativistic quantum-mechanical systems

    Science.gov (United States)

    Radożycki, Tomasz

    2016-11-01

    The probability density distributions for the ground states of certain model systems in quantum mechanics and for their classical counterparts are considered. It is shown, that classical distributions are remarkably improved by incorporating into them the Heisenberg uncertainty relation between position and momentum. Even the crude form of this incorporation makes the agreement between classical and quantum distributions unexpectedly good, except for the small area, where classical momenta are large. It is demonstrated that the slight improvement of this form, makes the classical distribution very similar to the quantum one in the whole space. The obtained results are much better than those from the WKB method. The paper is devoted to ground states, but the method applies to excited states too.

  10. Systematic of Nuclear Ground State Properties in Sr Isotope by Covariant Density Functional Theory

    Institute of Scientific and Technical Information of China (English)

    TIAN; Yuan

    2012-01-01

    <正>The hyperfine structure and isotope shifts of Sr-isotopes, both even-even and odd-even nuclei, are studied in the covariant density functional theory (DFT) with the new parameter set DD-PC1. Pairing correlation is treated by using the Bogoliubov with a separable form of the pairing interaction. Spin-parity,

  11. Predicting above-ground density and distribution of small mammal prey species at large spatial scales

    Science.gov (United States)

    Lucretia E. Olson; John R. Squires; Robert J. Oakleaf; Zachary P. Wallace; Patricia L. Kennedy

    2017-01-01

    Grassland and shrub-steppe ecosystems are increasingly threatened by anthropogenic activities. Loss of native habitats may negatively impact important small mammal prey species. Little information, however, is available on the impact of habitat variability on density of small mammal prey species at broad spatial scales. We examined the relationship between small mammal...

  12. Stochastic method for calculating the ground-state one-body density matrix of trapped Bose particles in one dimension

    Science.gov (United States)

    Buchman, Omri; Baer, Roi

    2017-09-01

    The one-body density matrix (OBDM) is a fundamental contraction of the Bose-Einstein condensate wave function, encapsulating its one-body properties. It serves as a major analysis tool with which the condensed component of the density can be identified. Despite its cardinal importance, calculating the ground-state OBDM of trapped interacting bosons is a challenge and to date OBDM calculations have been published only for homogeneous systems or for trapped weakly interacting bosons. In this paper we discuss an approach for computing the OBDM based on a double-walker diffusion Monte Carlo random walk coupled with a stochastic permanent calculation. We here describe the method and study some of its statistical convergence and properties applying it to some model systems.

  13. Tropospheric BrO column densities in the Arctic derived from satellite: retrieval and comparison to ground-based measurements

    Directory of Open Access Journals (Sweden)

    H. Sihler

    2012-11-01

    Full Text Available During polar spring, halogen radicals like bromine monoxide (BrO play an important role in the chemistry of tropospheric ozone destruction. Satellite measurements of the BrO distribution have become a particularly useful tool to investigate this probably natural phenomenon, but the separation of stratospheric and tropospheric partial columns of BrO is challenging. In this study, an algorithm was developed to retrieve tropospheric vertical column densities of BrO from data of high-resolution spectroscopic satellite instruments such as the second Global Ozone Monitoring Experiment (GOME-2. Unlike recently published approaches, the presented algorithm is capable of separating the fraction of BrO in the activated troposphere from the total BrO column solely based on remotely measured properties. The presented algorithm furthermore allows to estimate a realistic measurement error of the tropospheric BrO column. The sensitivity of each satellite pixel to BrO in the boundary layer is quantified using the measured UV radiance and the column density of the oxygen collision complex O4. A comparison of the sensitivities with CALIPSO LIDAR observations demonstrates that clouds shielding near-surface trace-gas columns can be reliably detected even over ice and snow. Retrieved tropospheric BrO columns are then compared to ground-based BrO measurements from two Arctic field campaigns in the Amundsen Gulf and at Barrow in 2008 and 2009, respectively. Our algorithm was found to be capable of retrieving enhanced near-surface BrO during both campaigns in good agreement with ground-based data. Some differences between ground-based and satellite measurements observed at Barrow can be explained by both elevated and shallow surface layers of BrO. The observations strongly suggest that surface release processes are the dominating source of BrO and that boundary layer meteorology influences the vertical distribution.

  14. Tropospheric BrO column densities in the Arctic from satellite: retrieval and comparison to ground-based measurements

    Directory of Open Access Journals (Sweden)

    H. Sihler

    2012-05-01

    Full Text Available During polar spring, halogen radicals like bromine monoxide (BrO play an important role in the chemistry of tropospheric ozone destruction. Satellite measurements of the BrO-distribution have become a particularly useful tool to investigate this probably natural phenomenon, but the separation of stratospheric and tropospheric partial columns of BrO is challenging. In this study, an algorithm was developed to retrieve tropospheric vertical column densities of BrO from data of high-resolution spectroscopic satellite instruments such as the second Global Ozone Monitoring Experiment (GOME-2. Unlike recently published approaches, the presented algorithm is capable of separating the fraction of BrO in the activated troposphere from the total BrO column solely based on remotely measured properties. The sensitivity of each satellite pixel to BrO in the boundary-layer is quantified using the measured UV-radiance and the column density of the oxygen collision complex O4. A comparison of the sensitivities with CALIPSO LIDAR observations demonstrates that clouds shielding near-surface trace-gas columns can be reliably detected even over ice and snow. Retrieved tropospheric BrO columns are then compared to ground-based BrO measurements from two Arctic field campaigns in the Amundsen Gulf and at Barrow in 2008 and 2009, respectively. Our algorithm was found to be capable of retrieving enhanced near-surface BrO during both campaigns in good agreement to ground-based data. Some differences between ground-based and satellite measurements observed at Barrow can be explained by both, elevated and shallow surface layers of BrO. The observations strongly suggest that surface release processes are the dominating source of BrO and that boundary-layer meteorology influences the vertical distribution.

  15. Diabatic-At-Construction Method for Diabatic and Adiabatic Ground and Excited States Based on Multistate Density Functional Theory.

    Science.gov (United States)

    Grofe, Adam; Qu, Zexing; Truhlar, Donald G; Li, Hui; Gao, Jiali

    2017-03-14

    We describe a diabatic-at-construction (DAC) strategy for defining diabatic states to determine the adiabatic ground and excited electronic states and their potential energy surfaces using the multistate density functional theory (MSDFT). The DAC approach differs in two fundamental ways from the adiabatic-to-diabatic (ATD) procedures that transform a set of preselected adiabatic electronic states to a new representation. (1) The DAC states are defined in the first computation step to form an active space, whose configuration interaction produces the adiabatic ground and excited states in the second step of MSDFT. Thus, they do not result from a similarity transformation of the adiabatic states as in the ATD procedure; they are the basis for producing the adiabatic states. The appropriateness and completeness of the DAC active space can be validated by comparison with experimental observables of the ground and excited states. (2) The DAC diabatic states are defined using the valence bond characters of the asymptotic dissociation limits of the adiabatic states of interest, and they are strictly maintained at all molecular geometries. Consequently, DAC diabatic states have specific and well-defined physical and chemical meanings that can be used for understanding the nature of the adiabatic states and their energetic components. Here we present results for the four lowest singlet states of LiH and compare them to a well-tested ATD diabatization method, namely the 3-fold way; the comparison reveals both similarities and differences between the ATD diabatic states and the orthogonalized DAC diabatic states. Furthermore, MSDFT can provide a quantitative description of the ground and excited states for LiH with multiple strongly and weakly avoided curve crossings spanning over 10 Å of interatomic separation.

  16. Effects of spatially variable snow cover on thermal regime and hydrology of an Arctic ice wedge polygon landscape identified using ground penetrating radar and LIDAR datasets

    Science.gov (United States)

    Gusmeroli, A.; Liljedahl, A. K.; Peterson, J. E.; Hubbard, S. S.; Hinzman, L. D.

    2012-12-01

    Ice wedge polygons are common in Arctic terrains underlain by permafrost. Permafrost degradation could transform low- into high centered polygons, causing profound changes in the hydrologic regime of Arctic lands, which in turn, could affect the energy balance and subsurface biodegradation of organic carbon responsible for greenhouse gas production. Understanding the linkages between microtopography, snow cover, thermal properties, and thaw depth is critical for developing a predictive understanding of terrestrial ecosystems and their feedbacks to climate. In this study, we use high frequency (500-1000 MHz) ground penetrating radar (GPR) data acquired in spring 2012 within the Next Generation Ecosystem Experiment (NGEE) study site in Barrow, AK to characterize the spatial variability of snow distribution. We compare it's distribution to microtopography, estimated using LIDAR data, and thaw depth, also estimated using ground penetrating radar collected at different times during the year and simulated over time using mechanistic thermal-hydrologic modeling. The high spatial resolution offered by LIDAR and ground penetrating radar permit detailed investigations of the control of microtopography on snow and thaw layer depth. Results suggest that microtopographical variations are responsible for substantial differences in snow accumulation. In low centered polygons, snow depth can be up to four times greater in the troughs than on the rims. Both modeling and observations suggest that the microtopography-governed snow thickness affects the thermal properties of the subsurface and thus the thaw layer thickness; regions with thicker snowpack generally correspond to regions of greater thaw depth. We conclude that a transition from low- to high centered polygons will not only impact watershed runoff but, since snow accumulation is sensitive to the microtopography, it will also impact snow distribution. In turn, snow distribution affects thaw depth thickness, and the

  17. The influence of vegetation cover on debris-flow density during an extreme rainfall in the northern Colorado Front Range

    Science.gov (United States)

    Rengers, Francis; Mcguire, Luke; Coe, Jeffrey A.; Kean, Jason W.; Baum, Rex L.; Staley, Dennis M.; Godt, Jonathan W.

    2016-01-01

    We explored regional influences on debris-flow initiation throughout the Colorado Front Range (Colorado, USA) by exploiting a unique data set of more than 1100 debris flows that initiated during a 5 day rainstorm in 2013. Using geospatial data, we examined the influence of rain, hillslope angle, hillslope aspect, and vegetation density on debris-flow initiation. In particular we used a greenness index to differentiate areas of high tree density from grass and bare soil. The data demonstrated an overwhelming propensity for debris-flow initiation on south-facing hillslopes. However, when the debris-flow density was analyzed with respect to total rainfall and greenness we found that most debris flows occurred in areas of high rainfall and low tree density, regardless of hillslope aspect. These results indicate that present-day tree density exerts a stronger influence on debris-flow initiation locations than aspect-driven variations in soil and bedrock properties that developed over longer time scales.

  18. Ground measurements of the hemispherical-directional reflectance of Arctic snow covered tundra for the validation of satellite remote sensing products

    Science.gov (United States)

    Ball, C. P.; Marks, A. A.; Green, P.; Mac Arthur, A.; Fox, N.; King, M. D.

    2013-12-01

    Surface albedo is the hemispherical and wavelength integrated reflectance over the visible, near infrared and shortwave infrared regions of the solar spectrum. The albedo of Arctic snow can be in excess of 0.8 and it is a critical component in the global radiation budget because it determines the proportion of solar radiation absorbed, and reflected, over a large part of the Earth's surface. We present here our first results of the angularly resolved surface reflectance of Arctic snow at high solar zenith angles (~80°) suitable for the validation of satellite remote sensing products. The hemispherical directional reflectance factor (HDRF) of Arctic snow covered tundra was measured using the GonioRAdiometric Spectrometer System (GRASS) during a three-week field campaign in Ny-Ålesund, Svalbard, in March/April 2013. The measurements provide one of few existing HDRF datasets at high solar zenith angles for wind-blown Arctic snow covered tundra (conditions typical of the Arctic region), and the first ground-based measure of HDRF at Ny-Ålesund. The HDRF was recorded under clear sky conditions with 10° intervals in view zenith, and 30° intervals in view azimuth, for several typical sites over a wavelength range of 400-1500 nm at 1 nm resolution. Satellite sensors such as MODIS, AVHRR and VIIRS offer a method to monitor the surface albedo with high spatial and temporal resolution. However, snow reflectance is anisotropic and is dependent on view and illumination angle and the wavelength of the incident light. Spaceborne sensors subtend a discrete angle to the target surface and measure radiance over a limited number of narrow spectral bands. Therefore, the derivation of the surface albedo requires accurate knowledge of the surfaces bidirectional reflectance as a function of wavelength. The ultimate accuracy to which satellite sensors are able to measure snow surface properties such as albedo is dependant on the accuracy of the BRDF model, which can only be assessed

  19. Ground and low-lying excited electronic states of graphene flakes: a density functional theory study

    Energy Technology Data Exchange (ETDEWEB)

    Tachikawa, Hiroto; Kawabata, Hiroshi, E-mail: hiroto@eng.hokudai.ac.jp [Division of Materials Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)

    2011-10-28

    Structures and electronic states of graphene flakes (finite and small sized graphenes) have been investigated by means of the density functional theory method. Sizes of graphene flakes examined in this study were n = 7, 10, 14, 19, 29 and 44, where n is the number of benzene rings in the graphene flake. The excitation energies of graphene flakes decreased gradually as a function of the number of the ring (n). The orbitals of the highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO) are localized in the edge region of the graphene flake. It was found that the edge region can react with a water molecule and H{sub 2}O is dissociated into OH radical and hydrogen atom (H) without an activation barrier. A lithium ion can bind strongly to the edge region. The ability of the edge region in the graphene flakes was discussed on the basis of theoretical results.

  20. Algorithm for Detection of Ground and Canopy Cover in Micropulse Photon-Counting Lidar Altimeter Data in Preparation for the ICESat-2 Mission

    Science.gov (United States)

    Herzfeld, Ute Christina; McDonald, Brian W.; Neumann, Thomas Allen; Wallin, Bruce F.; Neumann, Thomas A.; Markus, Thorsten; Brenner, Anita; Field, Christopher

    2014-01-01

    NASA's Ice, Cloud and Land Elevation Satellite-II (ICESat-2) mission is a decadal survey mission (2016 launch). The mission objectives are to measure land ice elevation, sea ice freeboard, and changes in these variables, as well as to collect measurements over vegetation to facilitate canopy height determination. Two innovative components will characterize the ICESat-2 lidar: 1) collection of elevation data by a multibeam system and 2) application of micropulse lidar (photon-counting) technology. A photon-counting altimeter yields clouds of discrete points, resulting from returns of individual photons, and hence new data analysis techniques are required for elevation determination and association of the returned points to reflectors of interest. The objective of this paper is to derive an algorithm that allows detection of ground under dense canopy and identification of ground and canopy levels in simulated ICESat-2 data, based on airborne observations with a Sigma Space micropulse lidar. The mathematical algorithm uses spatial statistical and discrete mathematical concepts, including radial basis functions, density measures, geometrical anisotropy, eigenvectors, and geostatistical classification parameters and hyperparameters. Validation shows that ground and canopy elevation, and hence canopy height, can be expected to be observable with high accuracy by ICESat-2 for all expected beam energies considered for instrument design (93.01%-99.57% correctly selected points for a beam with expected return of 0.93 mean signals per shot (msp), and 72.85%-98.68% for 0.48 msp). The algorithm derived here is generally applicable for elevation determination from photoncounting lidar altimeter data collected over forested areas, land ice, sea ice, and land surfaces, as well as for cloud detection.

  1. Ground-state properties of rare-earth metals: an evaluation of density-functional theory.

    Science.gov (United States)

    Söderlind, Per; Turchi, P E A; Landa, A; Lordi, V

    2014-10-15

    The rare-earth metals have important technological applications due to their magnetic properties, but are scarce and expensive. Development of high-performance magnetic materials with less rare-earth content is desired, but theoretical modeling is hampered by complexities of the rare earths electronic structure. The existence of correlated (atomic-like) 4f electrons in the vicinity of the valence band makes any first-principles theory challenging. Here, we apply and evaluate the efficacy of density-functional theory for the series of lanthanides (rare earths), investigating the influence of the electron exchange and correlation functional, spin-orbit interaction, and orbital polarization. As a reference, the results are compared with those of the so-called 'standard model' of the lanthanides in which electrons are constrained to occupy 4f core states with no hybridization with the valence electrons. Some comparisons are also made with models designed for strong electron correlations. Our results suggest that spin-orbit coupling and orbital polarization are important, particularly for the magnitude of the magnetic moments, and that calculated equilibrium volumes, bulk moduli, and magnetic moments show correct trends overall. However, the precision of the calculated properties is not at the level of that found for simpler metals in the Periodic Table of Elements, and the electronic structures do not accurately reproduce x-ray photoemission spectra.

  2. Search for the ground-state electronic configurations of correlated organometallic metallocenes from constraint density functional theory

    Science.gov (United States)

    Nawa, Kenji; Kitaoka, Yukie; Nakamura, Kohji; Imamura, Hiroshi; Akiyama, Toru; Ito, Tomonori; Weinert, M.

    2016-07-01

    The ground-state electronic configurations of the correlated organometallic metallocenes, M Cp2,M =V , Cr, Mn, Fe, Co, and Ni, are investigated using constraint density functional theory combined with nonempirical Ueff parameters determined from linear-response theory. The relative stability of the various d -orbital electronic configurations of these organometallic molecules is found to be sensitive to the amount of correlation. Using nonempirical values of Ueff, the calculated electronic configurations are in agreement with the experiments: 4A2 g ,3E2 g ,6A1 g ,1A1 g ,2E1 g , and 3A2 g for the VCp2,CrCp2,MnCp2,FeCp2,CoCp2 , and NiCp2, respectively.

  3. Calibration and evaluation of CCD spectroradiometers for ground-based and airborne measurements of spectral actinic flux densities

    Science.gov (United States)

    Bohn, Birger; Lohse, Insa

    2017-09-01

    The properties and performance of charge-coupled device (CCD) array spectroradiometers for the measurement of atmospheric spectral actinic flux densities (280-650 nm) and photolysis frequencies were investigated. These instruments are widely used in atmospheric research and are suitable for aircraft applications because of high time resolutions and high sensitivities in the UV range. The laboratory characterization included instrument-specific properties like the wavelength accuracy, dark signal, dark noise and signal-to-noise ratio (SNR). Spectral sensitivities were derived from measurements with spectral irradiance standards. The calibration procedure is described in detail, and a straightforward method to minimize the influence of stray light on spectral sensitivities is introduced. From instrument dark noise, minimum detection limits ≈ 1 × 1010 cm-2 s-1 nm-1 were derived for spectral actinic flux densities at wavelengths around 300 nm (1 s integration time). As a prerequisite for the determination of stray light under field conditions, atmospheric cutoff wavelengths were defined using radiative transfer calculations as a function of the solar zenith angle (SZA) and total ozone column (TOC). The recommended analysis of field data relies on these cutoff wavelengths and is also described in detail taking data from a research flight on HALO (High Altitude and Long Range Research Aircraft) as an example. An evaluation of field data was performed by ground-based comparisons with a double-monochromator-based, highly sensitive reference spectroradiometer. Spectral actinic flux densities were compared as well as photolysis frequencies j(NO2) and j(O1D), representing UV-A and UV-B ranges, respectively. The spectra expectedly revealed increased daytime levels of stray-light-induced signals and noise below atmospheric cutoff wavelengths. The influence of instrument noise and stray-light-induced noise was found to be insignificant for j(NO2) and rather limited for j(O1D

  4. The effects of initial planting density on above- and below-ground biomass in a 25-year-old Fagus orientalis Lipsky plantation in Hopa, Turkey

    OpenAIRE

    Güner, Sinan; Yağcı, Volkan; Tilki, Fahrettin; Çelik, Nejat

    2010-01-01

    The aim of this study was to determine the influence of initial planting density on above- and below- ground biomass in 25 years old oriental beech stands located in Hopa, Artvin, Turkey. The initial spacings used in this study were 0.7 x 2.0 m ( high planting density) and 2.0 x 2.0 m (low planting density). To analyse the planting density response of trees of different sizes (diameter), the sample trees within each stand density class were classified into four dbh classes (dbh1, dbh2, dbh3, ...

  5. Density and fledging success of ground-nesting passerines in Conservation Reserve Program fields in the northeastern Great Plains

    Science.gov (United States)

    Koford, Rolf R.

    1999-01-01

    The Conservation Reserve Program, initiated in 1985, was designed primarily to reduce soil erosion and crop surpluses. A secondary benefit was the provision of habitat for wildlife. Grassland bird populations, many of which declined in the decades prior to the Conservation Reserve Program, may have benefited from the Conservation Reserve Program if reproduction in this newly available habitat has been at least as high as it would have been in the absence of the Conservation Reserve Program. On study areas in North Dakota and Minnesota, I examined breeding densities and fledging success of grassland birds in Conservation Reserve Program fields and in an alternative habitat of similar structure, idle grassland fields on federal Waterfowl Production Areas. Fields were 10 to 25 hectares in size. The avifaunas of these two habitats were similar, although brush-dependent species were more abundant on Waterfowl Protection Areas. The common species in these habitats included ones whose continental populations have declined, such as Grasshopper Sparrow (Ammodramus savannarum), Savannah Sparrow (Passerculus sandwichensis), and Bobolink (Dolichonyx oryzivorus). These ground-nesting species were pooled with other ground nesters in an analysis of fledging success, which revealed no significant differences between habitats, between states, or among years (1991-1993). Predation was the primary cause of nest failure. I concluded that Conservation Reserve Program fields in this region were suitable breeding habitat for several species whose populations had declined prior to the Conservation Reserve Program era. This habitat appeared to be as secure for nests of ground-nesting birds as another suitable habitat in North Dakota and Minnesota.

  6. Spawning aggregation of white-streaked grouper Epinephelus ongus: spatial distribution and annual variation in the fish density within a spawning ground

    Science.gov (United States)

    Sato, Taku; Kawabata, Yuuki; Okuyama, Junichi

    2017-01-01

    White-streaked grouper (Epinephelus ongus) is an important fisheries target and forms spawning aggregations at particular spawning grounds. The aims of the present study were to investigate the ecological characteristics of annual spawning aggregations such as (1) spatial variations in the density of E. ongus at the spawning ground, (2) the relationship between fish density and environmental variables, (3) inter-annual variations in the spawning aggregation, (4) the proportion of males to females at the spawning ground for several days pre—and post-spawning and (5) the relationship between male density and female density at the protected spawning ground, based on observations over five years at an Okinawan coral reef. Although the protected spawning ground area was large (ca. 2,500 m × 700 m), high density of E. ongus (over 25 individuals per 100 m2) was found in a limited area (within c.a. 750 m × 50 m). Current velocity and coverage of rocks had significant positive effects on the spatial distribution of E. ongus at the spawning ground. Inter-annual variation in the degree of aggregation was found and this variation was explained by the annual variation of mean seawater temperature during 40 days before the spawning day. The male–female ratio (male:female) at the spawning ground was ca. 3:1 for three years (May 2012, May 2014 and May 2015) whereas >13:1 for one year (May 2013). Significant positive relationships between male density and female density were found at the aggregation sites. It is suggested that E. ongus use aggregation sites with greater current velocity to reduce the risk of egg predation and seawater temperature is one of the main factors that is responsible for determining the degree of aggregation. It is also suggested that females possibly select sites with a greater density of males and this selection behavior might be the reason why females arrived at the spawning ground after the arrival of the males. For effective management of

  7. An Algorithm for Detection of Ground and Canopy Cover in Micropulse Photon-Counting Lidar Altimeter Data in Preparation of the ICESat-2 Mission

    Science.gov (United States)

    Herzfeld, Ute C.; McDonald, Brian W.; Wallins, Bruce F.; Markus, Thorsten; Neumann, Thomas A.; Brenner, Anita

    2012-01-01

    The Ice, Cloud and Land Elevation Satellite-II (ICESat-2) mission has been selected by NASA as a Decadal Survey mission, to be launched in 2016. Mission objectives are to measure land ice elevation, sea ice freeboard/ thickness and changes in these variables and to collect measurements over vegetation that will facilitate determination of canopy height, with an accuracy that will allow prediction of future environmental changes and estimation of sea-level rise. The importance of the ICESat-2 project in estimation of biomass and carbon levels has increased substantially, following the recent cancellation of all other planned NASA missions with vegetation-surveying lidars. Two innovative components will characterize the ICESat-2 lidar: (1) Collection of elevation data by a multi-beam system and (2) application of micropulse lidar (photon counting) technology. A micropulse photon-counting altimeter yields clouds of discrete points, which result from returns of individual photons, and hence new data analysis techniques are required for elevation determination and association of returned points to reflectors of interest including canopy and ground in forested areas. The objective of this paper is to derive and validate an algorithm that allows detection of ground under dense canopy and identification of ground and canopy levels in simulated ICESat-2-type data. Data are based on airborne observations with a Sigma Space micropulse lidar and vary with respect to signal strength, noise levels, photon sampling options and other properties. A mathematical algorithm is developed, using spatial statistical and discrete mathematical concepts, including radial basis functions, density measures, geometrical anisotropy, eigenvectors and geostatistical classification parameters and hyperparameters. Validation shows that the algorithm works very well and that ground and canopy elevation, and hence canopy height, can be expected to be observable with a high accuracy during the ICESat

  8. Synthesis and Characteristics of Protective Coating on Thin Cover Layer for High Density-Digital Versatile Disc

    Science.gov (United States)

    Chang, Dohoon; Yoon, Duseop; Ro, Myongdo; Hwang, Inoh; Park, Insik; Shin, Dongho

    2003-02-01

    This study relates to the optical disc used in the high-density digital versatile disc (HD-DVD) system that uses a high numerical aperture of 0.85 at 405 nm wavelength. The disc has a protective layer formed on the light-incident surface for protection against damage and dust. The synthesis of the UV-curable resinous material, as means of making a protective layer within sufficient margins of thickness variation and optical and mechanical properties, was investigated. In addition, the dynamic characteristics, including reflectivity, fluctuation of the RF signal and noise level, were also investigated.

  9. Experimental Results of Thin-Film Photovoltaic Cells in a Low Density LEO Plasma Environment: Ground Tests

    Science.gov (United States)

    Galofaro, Joel T.; Vayner, Boris V.

    2006-01-01

    Plasma ground testing results, conducted at the Glenn Research Center (GRC) National Plasma Interaction (N-PI) Facility, are presented for a number of thin-film photovoltaic cells. The cells represent a mix of promising new technologies identified by the Air Force Research Laboratory (AFRL) under the CYGNUS Space Science Technology Experiment (SSTE-4) Program. The current ground tests are aimed at characterizing the performance and survivability of thin film technologies in the harsh low earth orbital space environment where they will be flown. Measurements of parasitic current loss, charging/dielectric breakdown of cover-slide coatings and arcing threshold tests are performed for each individual cell. These measurements are followed by a series of experiments designed to test for catastrophic arc failure mechanisms. A special type of power supply, called a solar array simulator (SAS) with adjustable voltage and current limits on the supply s output, is employed to bias two adjacent cells at a predetermined voltage and current. The bias voltage is incrementally ramped up until a sustained arc results. Sustained arcs are precursors to catastrophic arc failure where the arc current rises to a maximum value for long timescales often ranging between 30 to 100 sec times. Normal arcs by comparison, are short lived events with a timescale between 10 to 30 sec. Sustained arcs lead to pyrolization with extreme cell damage and have been shown to cause the loss of entire array strings in solar arrays. The collected data will be used to evaluate the suitability of thin-film photovoltaic technologies for future space operations.

  10. Influence of shrub cover vegetal and slope length on soil bulk density; Influencia de la cubierta vegetal arbustiva y la longitud de la ladera sobre la densidad aparente del suelo

    Energy Technology Data Exchange (ETDEWEB)

    Bienes, R.; Jimenez, R.; Ruiz, M.; Garcia-Estringana, P.; Marques, M. J.

    2009-07-01

    In arid and semiarid environments of the Mediterranean climate, the shrub species play an important role in the revegetation of abandoned lands, which enables to control the soil losses, organic material and water. In this article are compared the results obtained under different revegetation in abandoned lands in the central area of Spain. In these revegetation has been used two native shrubs: A triplex halimus (Ah) and Retama sphaerocarpa (Rs), and were analyzed the influence of these revegetation in the contents of organic material of soil and apparent density in 5 years time after planting. As control, have been considered the pieces of ground with spontaneous vegetation abandoned in the same date that the shrubs revegetation. Atriplex halimus gives to the soil a covering capable to intercept a big amount of water drops absorbing a great amount part of the kinetic energy of the rain, while provides a microclimates as a result of be able to soften the wind, the temperature and the evaporation-transpiration, which makes it efficient to control the erosion and the desertification (Le Houerou, 2000). Retama sphaerocarpa was chosen because it is a native shrub very characteristic, and, due to its symbiosis with the Bradyrhizobium, enriches the soil in nitrogen, which is taken by the nitrophilous species enhancing the spontaneous vegetal covering. (Author) 9 refs.

  11. Expression profile analysis of genes involved in horizontal gravitropism bending growth in the creeping shoots of ground-cover chrysanthemum by suppression subtractive hybridization.

    Science.gov (United States)

    Xia, Shengjun; Chen, Yu; Jiang, Jiafu; Chen, Sumei; Guan, Zhiyong; Fang, Weimin; Chen, Fadi

    2013-01-01

    The molecular mechanisms underlying gravitropic bending of shoots are poorly understood and how genes related with this growing progress is still unclear. To identify genes related to asymmetric growth in the creeping shoots of chrysanthemum, suppression subtractive hybridization was used to visualize differential gene expression in the upper and lower halves of creeping shoots of ground-cover chrysanthemum under gravistimulation. Sequencing of 43 selected clones produced 41 unigenes (40 singletons and 1 unigenes), which were classifiable into 9 functional categories. A notable frequency of genes involve in cell wall biosynthesis up-regulated during gravistimulation in the upper side or lower side were found, such as beta tubulin (TUB), subtilisin-like protease (SBT), Glutathione S-transferase (GST), and expensing-like protein (EXP), lipid transfer proteins (LTPs), glycine-rich protein (GRP) and membrane proteins. Our findings also highlighted the function of some metal transporter during asymmetric growth, including the boron transporter (BT) and ZIP transporter (ZT), which were thought primarily for maintaining the integrity of cell walls and played important roles in cellulose biosynthesis. CmTUB (beta tubulin) was cloned, and the expression profile and phylogeny was examined, because the cytoskeleton of plant cells involved in the plant gravitropic bending growth is well known.

  12. Diversity and stability of arthropod community in peach orchard under effects of ground cover vegetation%桃园生草对桃树节肢动物群落多样性与稳定性的影响

    Institute of Scientific and Technical Information of China (English)

    蒋杰贤; 万年峰; 季香云; 淡家贵

    2011-01-01

    A comparative study was conducted on the arthropod community in peach orchards with and without ground cover vegetation. In the orchard with ground cover vegetation, the individuals of beneficial, neutral, and phytophagous arthropods were 1. 48, 1. 84 and 0. 64 times of those in the orchard without ground cover vegetation, respectively, but the total number of arthropods had no significant difference with that in the orchard without ground cover vegetation. The species richness, Shannon' s diversity, and Pielou' s evenness index of the arthropods in the orchard with ground cov-er vegetation were 83. 733±4. 932, 4. 966±0. 110, and 0. 795±0. 014, respectively, being signifi-cantly higher than those in the orchard without ground cover vegetation, whereas the Berger-Parker' s dominance index was 0. 135±0. 012, being significantly lower than that (0. 184±0. 018) in the orchard without ground cover vegetation. There were no significant differences in the stability indices S/N and Sd/Sp between the two orchards, but the Nn/Np, Nd/Np, and Sn/Sp in the orchard with ground cover vegetation were 0. 883±0. 123. 1714±0. 683, and 0. 781 ±0. 040, respectively, being significantly higher than those in the orchard without ground cover vegetation. Pearson' s cor-relation analysis indicated that in the orchard with ground cover vegetation, the Shannon' s diversity index was significantly negatively correlated with Nd/Np, Sd/Sp, and S/N but had no significant correlations with Nn/Np and Sn/Sp, whereas in the orchard without ground cover vegetation, the di-versity index was significantly positively correlated with Nn/Np and Nd/Np and had no significant correlations with Sd/Sp ,Sn/Sp, and S/N.%对种植白三叶草的桃园(生草桃园)和非生草桃园的桃树节肢动物群落进行分析比较.结果表明:生草桃园桃树天敌、中性类群和植食类群数量分别是非生草桃园的1.48、1.84和0.64倍,而节肢动物群落个体总数无显著差异;与非

  13. Exercise attenuates the increase in plasma monounsaturated fatty acids and high-density lipoprotein cholesterol but not high-density lipoprotein 2b cholesterol caused by high-oleic ground beef in women.

    Science.gov (United States)

    Gilmore, L Anne; Crouse, Stephen F; Carbuhn, Aaron; Klooster, Jennifer; Calles, José Antonio Elias; Meade, Thomas; Smith, Stephen B

    2013-12-01

    We hypothesized that dietary monounsaturated fatty acids (MUFA) and exercise increase high-density lipoprotein cholesterol (HDL-C) by independent mechanisms, so there would be additive effects between a single, intensive session of exercise and high-MUFA ground beef on HDL-C and blood risk factors for cardiovascular disease. Seventeen postmenopausal women completed a 2-way crossover design in which they consumed five 114-g ground beef patties per week for two 6-week periods separated by a 4-week washout (habitual diet) period. The ground beef patties contained 21% total fat with either 9.97 (low-MUFA) or 12.72 (high-MUFA) g total MUFA. Blood was taken at entry, at the end of each 6-week diet period, after the 4-week washout period, and 24 hours after aerobic exercise sessions (75% VO₂peak, 2.07 MJ). After the ground beef intervention, the high-MUFA ground beef increased plasma palmitoleic acid and oleic acid, low-density lipoprotein (LDL) particle density, HDL-C, and HDL2b-C (all P density. After the washout (habitual diet) period, the single exercise session increased serum LDL cholesterol, HDL-C, and HDL2a and decreased TAG and oleic acid. After the low-MUFA ground beef diet, exercise increased LDL size and HDL density and decreased LDL density and very low-density lipoprotein cholesterol, but had no effect on HDL-C fractions. After the high-MUFA ground beef intervention, exercise decreased palmitioleic acid, oleic acid, HDL-C, and HDL2a-C, but not HDL2b-C. Contrary to our hypothesis, the effects of exercise and a high-MUFA diet were not additive; instead, exercise attenuated the effects of the high-MUFA ground beef on HDL-C and plasma MUFAs. The differential effects of high-MUFA ground beef and exercise on HDL2a-C and HDL2b-C indicate that diet and exercise affect HDL-C by different mechanisms.

  14. Monitoring of a debris-covered and avalanche-fed glacier in the Eastern Italian Alps using ground-based SfM-MVS

    Science.gov (United States)

    Piermattei, Livia; Carturan, Luca; Cazorzi, Federico; Colucci, Renato R.; Dalla Fontana, Giancarlo; Forte, Emanuele

    2015-04-01

    The Montasio Occidentale glacier is a 0.07 km2 wide, avalanche-fed glacier located at very low-altitude (1860-2050 m a.s.l.) in the Eastern Italian Alps. The glacier is still active and shows a detectable mass transfer from the accumulation area to the lower ablation area, which is covered by a thick debris mantle. Geometric changes and mass balance have been monitored starting in 2010, combining glaciological methods and high-resolution geodetic surveying with a terrestrial laser scanner (TLS). The TLS technique has proved to be very effective in determining the volume change of this glacier, but presents several limitations as high costs, high level of specialized training and low portability. On the other hand, the recent improvements in close-range photogrammetric techniques like the Structure from Motion (SfM), combined with dense image matching algorithms as Multi View Stereo (MVS), make them competitive for high quality 3D models production. The purpose of this work was to apply ground-based photogrammetric surveys for the monitoring of the annual mass balance and surface processes of Montasio Occidentale glacier. A consumer-grade SLR camera and the SfM-MVS software PhotoScan were used to detect the changes in the surface topography of the glacier from 2012 to 2014. Different data acquisition settings were tested, in order to optimize the quality and the spatial coverage of the 3D glacier model. The accuracy of the image-based 3D models was estimated in stable areas outside the glacier, using the TLS 3D model as reference. A ground penetrating radar (GPR) survey was carried out in 2014, simultaneously to the photogrammetric survey, that was used to compare the snow height estimations obtained by photogrammetry with those obtained by geophysics. The achieved results indicate that the resolution and accuracy of the 3D models generated by the SfM-MVS technique are comparable with those obtained from TLS surveys. Consequently, almost identical volumetric changes

  15. Thermoplastic elastomers blends based on linear low density polyethylene, ethylene-1-octene copolymers and ground rubber tire

    Directory of Open Access Journals (Sweden)

    Marisa Cristina Guimarães Rocha

    2014-01-01

    Full Text Available Blends of linear low density polyethylene (LLDPE ethylene-1-octene copolymers (EOC, with different 1-octene (OC content, and ground rubber tire (GRT were prepared by melt mixing in a twin screw extruder. Five different compositions of LLDPE/EOC/GRT blends were processed in the extruder to evaluate the effect of EOC addition to the LLDPE/GRT blends. The addition of EOC to LLDPE/GRT blends improves the mechanical properties. Besides, the replacement of 5% of GRT by EOC grades (OC = 20 or 30 wt % in the 50/50 LLDPE/GRT blend, leads to a significant increase of ultimate tensile properties. The EOC comonomer content affects the properties of LLDPE/EOC and LLDPE/EOC/GRT blends. Dynamical-mechanical analyses showed that, with the addition of EOC to LLDPE/GRT blends, the Tg of GRT and the Tg of EOC are closer. This effect is more pronounced when the EOC with the highest content of comonomer (30 wt % is added to LLDPE/GRT blend. In this case, only one peak related to the Tg of the rubber phase can be visualized in the amorphous region. These findings indicate that EOC may act as compatibilizer agent for LLDPE/GRT blends.

  16. Non-phytoseiid Mesostigmata within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants and additional collection records of mites in citrus orchards.

    Science.gov (United States)

    Childers, Carl C; Ueckermann, Eduard A

    2015-03-01

    Seven citrus orchards on reduced- to no-pesticide spray programs in central and south central Florida were sampled for non-phytoseiid mesostigmatid mites. Inner and outer canopy leaves, fruits, twigs and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. A total of 431 samples from one or more of 82 vine or ground cover plants were sampled monthly in five of the seven orchards. Two of the seven orchards (Mixon I and II) were on full herbicide programs and vines and ground cover plants were absent. A total of 2,655 mites (26 species) within the families: Ascidae, Blattisociidae, Laelapidae, Macrochelidae, Melicharidae, Pachylaelapidae and Parasitidae were identified. A total of 685 mites in the genus Asca (nine species: family Ascidae) were collected from within tree samples, 79 from vine or ground cover plants. Six species of Blattisociidae were collected: Aceodromus convolvuli, Blattisocius dentriticus, B. keegani, Cheiroseius sp. near jamaicensis, Lasioseius athiashenriotae and L. dentatus. A total of 485 Blattisociidae were collected from within tree samples compared with 167 from vine or ground cover plants. Low numbers of Laelapidae and Macrochelidae were collected from within tree samples. One Zygoseius furciger (Pachylaelapidae) was collected from Eleusine indica. Four species of Melicharidae were identified from 34 mites collected from within tree samples and 1,190 from vine or ground cover plants: Proctolaelaps lobatus was the most abundant species with 1,177 specimens collected from seven ground cover plants. One Phorytocarpais fimetorum (Parasitidae) was collected from inner leaves and four from twigs. Species of Ascidae, Blattisociidae, Melicharidae, Laelapidae and Pachylaelapidae were collected from 31 of the 82 vine or ground cover plants sampled, representing only a small fraction of the total number of Phytoseiidae collected from the same plants. Including the

  17. The Investigation of Species and Application of Ground Cover Plants in Jiaozuo%焦作市地被植物种类及应用调查

    Institute of Scientific and Technical Information of China (English)

    韩红军; 张桂芝; 马君丽; 孔德政

    2012-01-01

    根据对焦作市建成区地被植物进行实地调查,统计得出焦作市作为地被植物应用的灌木,藤本,一、二年生花卉,宿根、球根花卉、草类共有192种65科151属.灌木应用较多,宿根、球根花卉,一、二年生花卉应用较少;提出了应用频率最高的地被植物有:马棘、月季、剑麻、铺地柏、迎春等;焦作地被植物应用形式主要有以下几种;模纹花坛和绿篱,旷地造景,路缘造景等.最后提出优化灌草比例,引进新优品种的建议.%Based on the investigation of ground cover plants, which be divided into Bush, Fujimoto, one or two annual flower, Perennial and bulbs flowers and grasses, which we proposes 192 species in the Building area in the city of Jiaozuo belong to 65 families and 151 genera. Bush is widely used, on the contrary, one or two annual flowers and Perennial and bulbs flowers used very seldom. And we discover these plants as indigofera and rose and jasmine and sisal and winter juniper etc are used the most frequently. There are these kinds of application forms as follows: mode pattern flower and hedgerow, open areas landscaping, road edge landscaping. At the last, we proposed that Optimization the Proportion of bush and grass and introduction new and excellent variety.

  18. Optimizing placements of ground-based snow sensors for areal snow cover estimation using a machine-learning algorithm and melt-season snow-LiDAR data

    Science.gov (United States)

    Oroza, C.; Zheng, Z.; Glaser, S. D.; Bales, R. C.; Conklin, M. H.

    2016-12-01

    We present a structured, analytical approach to optimize ground-sensor placements based on time-series remotely sensed (LiDAR) data and machine-learning algorithms. We focused on catchments within the Merced and Tuolumne river basins, covered by the JPL Airborne Snow Observatory LiDAR program. First, we used a Gaussian mixture model to identify representative sensor locations in the space of independent variables for each catchment. Multiple independent variables that govern the distribution of snow depth were used, including elevation, slope, and aspect. Second, we used a Gaussian process to estimate the areal distribution of snow depth from the initial set of measurements. This is a covariance-based model that also estimates the areal distribution of model uncertainty based on the independent variable weights and autocorrelation. The uncertainty raster was used to strategically add sensors to minimize model uncertainty. We assessed the temporal accuracy of the method using LiDAR-derived snow-depth rasters collected in water-year 2014. In each area, optimal sensor placements were determined using the first available snow raster for the year. The accuracy in the remaining LiDAR surveys was compared to 100 configurations of sensors selected at random. We found the accuracy of the model from the proposed placements to be higher and more consistent in each remaining survey than the average random configuration. We found that a relatively small number of sensors can be used to accurately reproduce the spatial patterns of snow depth across the basins, when placed using spatial snow data. Our approach also simplifies sensor placement. At present, field surveys are required to identify representative locations for such networks, a process that is labor intensive and provides limited guarantees on the networks' representation of catchment independent variables.

  19. Inferring Average Ground Profiles of the Muon Density of Inclined Air Showers from Monte-Carlo Simulations at Ultra-High Energy

    CERN Document Server

    Dembinski, Hans; Deligny, Olivier; Hebbeker, Thomas

    2009-01-01

    A standard method to measure ultra-high energy cosmic rays is the sampling of the ground particle profile of the extensive air shower that is produced in the atmosphere with an array of surface detectors. The primary energy of inclined air showers with zenith angles >60 Deg can be reconstructed by using simulated 2-D profiles of the ground density of muons. We will present an effective way to extract such profiles from a library of Monte-Carlo simulated air showers. Also, we will demonstrate a way to speed up the simulation of ground profiles of the muon density in very inclined showers by three orders of magnitude, if only the muon component in the shower is of interest.

  20. Monitoring of the mass density profile along the 0° geomagnetic longitude during magnetic storms with the use of ground magnetometers.

    Science.gov (United States)

    Romanova, N.; Stepanova, M. V.; Kozyreva, O. V.; Pilipenko, V.; Zesta, E.

    2015-12-01

    Ground magnetometers offer a very cheap and robust means of globally monitoring the magnetospheric mass density, by determining the ULF field line resonant frequency. ULF waves are almost always present in near-Earth environment and are generated by the solar wind interaction with the terrestrial magnetosphere. These waves from the magnetopause propagate through the magnetosphere. When they encounter a field line that resonates at the same frequency, coupling to the Alfven field line oscillations occurs and the resonance can be detected on the ground at that particular latitude. There are different methods for determining resonant frequencies from ground ULF waves. the density profiles along the 0° geomagnetic longitude were obtained using both the gradient and the amplitude-phase methods for the analysis of the magnetic field data from the magnetometer arrays: SAMBA (South American Meridional B-field Array), MAGDAS and American Antarctic bases (Palmer, WAIS-D). We compared the density profiles during quiet magnetic conditions and during strong magnetic storms (recovery phase). It is shown that in the recovery phase of strong magnetic storms (Dst <-150 nT) profile of the equatorial mass density varies greatly in comparison with the density distribution in quiet days.

  1. An ecology of prestige in New York City: examining the relationships among population density, socio-economic status, group identity, and residential canopy cover.

    Science.gov (United States)

    Grove, J Morgan; Locke, Dexter H; O'Neil-Dunne, Jarlath P M

    2014-09-01

    Several social theories have been proposed to explain the uneven distribution of vegetation in urban residential areas: population density, social stratification, luxury effect, and ecology of prestige. We evaluate these theories using a combination of demographic and socio-economic predictors of vegetative cover on all residential lands in New York City. We use diverse data sources including the City's property database, time-series demographic and socio-economic data from the US Census, and land cover data from the University of Vermont's Spatial Analysis Lab (SAL). These data are analyzed using a multi-model inferential, spatial econometrics approach. We also examine the distribution of vegetation within distinct market categories using Claritas' Potential Rating Index for Zipcode Markets (PRIZM™) database. These categories can be disaggregated, corresponding to the four social theories. We compare the econometric and categorical results for validation. Models associated with ecology of prestige theory are more effective for predicting the distribution of vegetation. This suggests that private, residential patterns of vegetation, reflecting the consumption of environmentally relevant goods and services, are associated with different lifestyles and lifestages. Further, our spatial and temporal analyses suggest that there are significant spatial and temporal dependencies that have theoretical and methodological implications for understanding urban ecological systems. These findings may have policy implications. Decision makers may need to consider how to most effectively reach different social groups in terms of messages and messengers in order to advance land management practices and achieve urban sustainability.

  2. An Ecology of Prestige in New York City: Examining the Relationships Among Population Density, Socio-economic Status, Group Identity, and Residential Canopy Cover

    Science.gov (United States)

    Grove, J. Morgan; Locke, Dexter H.; O'Neil-Dunne, Jarlath P. M.

    2014-09-01

    Several social theories have been proposed to explain the uneven distribution of vegetation in urban residential areas: population density, social stratification, luxury effect, and ecology of prestige. We evaluate these theories using a combination of demographic and socio-economic predictors of vegetative cover on all residential lands in New York City. We use diverse data sources including the City's property database, time-series demographic and socio-economic data from the US Census, and land cover data from the University of Vermont's Spatial Analysis Lab (SAL). These data are analyzed using a multi-model inferential, spatial econometrics approach. We also examine the distribution of vegetation within distinct market categories using Claritas' Potential Rating Index for Zipcode Markets (PRIZM™) database. These categories can be disaggregated, corresponding to the four social theories. We compare the econometric and categorical results for validation. Models associated with ecology of prestige theory are more effective for predicting the distribution of vegetation. This suggests that private, residential patterns of vegetation, reflecting the consumption of environmentally relevant goods and services, are associated with different lifestyles and lifestages. Further, our spatial and temporal analyses suggest that there are significant spatial and temporal dependencies that have theoretical and methodological implications for understanding urban ecological systems. These findings may have policy implications. Decision makers may need to consider how to most effectively reach different social groups in terms of messages and messengers in order to advance land management practices and achieve urban sustainability.

  3. Water-saving ground cover rice production system reduces net greenhouse gas fluxes in an annual rice-based cropping system

    Directory of Open Access Journals (Sweden)

    Z. Yao

    2014-06-01

    Full Text Available To safeguard food security and preserve precious water resources, the technology of water-saving ground cover rice production system (GCRPS is being increasingly adopted for the rice cultivation. However, changes in soil water status and temperature under GCRPS may affect soil biogeochemical processes that control the biosphere–atmosphere exchanges of methane (CH4, nitrous oxide (N2O and carbon dioxide (CO2. The overall goal of this study is to better understand how net ecosystem greenhouse gas exchanges (NEGE and grain yields are affected by GCRPS in an annual rice-based cropping system. Our evaluation was based on measurements of the CH4 and N2O fluxes and soil heterotrophic respiration (CO2 emission over a complete year, as well as the estimated soil carbon sequestration intensity for six different fertilizer treatments for conventional paddy and GCRPS. The fertilizer treatments included urea application and no N fertilization for both conventional paddy (CUN and CNN and GCRPS (GUN and GNN, solely chicken manure (GCM and combined urea and chicken manure applications (GUM for GCRPS. Averaging across all the fertilizer treatments, GCRPS increased annual N2O emission and grain yield by 40% and 9%, respectively, and decreased annual CH4 emission by 69%, while GCRPS did not affect soil CO2 emissions relative to the conventional paddy. The annual direct emission factors of N2O were 4.01, 0.087 and 0.50% for GUN, GCM and GUM, respectively, and 1.52% for the conventional paddy (CUN. The annual soil carbon sequestration intensity under GCRPS was estimated to be an average of −1.33 Mg C ha−1 yr−1, which is approximately 44% higher than the conventional paddy. The annual NEGE were 10.80–11.02 Mg CO2-eq ha−1 yr−1 for the conventional paddy and 3.05–9.37 Mg CO2-eq ha−1 yr−1 for the GCRPS, suggesting the potential feasibility of GCRPS in reducing net greenhouse effect from rice cultivation. Using organic fertilizers for GCRPS

  4. Pre-flyby Determination Of The Size, Shape, Pole, Density, And Satellites Of (21) Lutetia From Ground-based Observations

    Science.gov (United States)

    Merline, William J.; Carry, B.; Drummond, J. D.; Conrad, A.; Chapman, C. R.; Kaasalainen, M.; Leyrat, C.; Weaver, H. A.; Tamblyn, P. M.; Christou, J. C.; Dumas, C.; Kryszczynska, A.; Colas, F.; Bernasconi, L.; Behrend, R.; Vachier, F.; Polinska, M.; Roy, R.; Naves, R.; Poncy, R.; Wiggins, P.

    2010-10-01

    Prior to the flyby of (21) Lutetia by Rosetta, we initiated a campaign of observations to characterize the system, primarily using ground-based adaptive optics (AO) on large telescopes, including Keck, Gemini, and VLT. We coordinated these efforts with HST observations (Weaver et al. 2010 A&A in press) made in support of the Rosetta ALICE UV spectrometer. Lutetia was 0.10" in diameter, allowing disk-resolved imaging with AO and tracking of its shape during rotation. We modeled the shape using both a triaxial-ellipsoid model (Drummond et al. 2010 A&A submitted) and a full 3D radius-vector model (Carry et al. 2010 A&A submitted, in which we combine AO imaging with decades of lightcurve data to produce an improved 3D model using our inversion algorithm KOALA). To overcome limitations in each model, we combined the best aspects of each to produce our best-estimate 3D shape model, a hybrid having ellipsoid-equivalent dimensions of 124 x 101 x 93 km (± 5 x 4 x 13 km) and effective diameter 105 ± 7 km. We find the spin axis of Lutetia to lie within 5 deg of [long, lat (52,-6)] or [RA DEC (52,+12)], and determine an improved sidereal period of 8.168270 ± 0.000001 h. We predicted the geometry of Lutetia during the flyby and showed that the southern hemisphere would be in seasonal shadow at that time. The model suggests the presence of several concavities that may be associated with large impacts. Using two separately determined masses and the volume of our hybrid model, we estimate a density of 3.5 ± 1.1 or 4.3 ± 0.8 g/cc, favoring an enstatite-chondrite composition for this large M-type asteroid, although other compositions are formally allowed. No satellites larger than 1 km diameter were detected in the AO-data over a significant fraction of the Hill sphere (10-240 asteroid radii).

  5. Correlation between Change Rates of GRACE-derived Density and Ground-measured Temperature in Tibetan Plateau, 2004-2008

    Science.gov (United States)

    Zhang, K.; Ma, J.

    2011-12-01

    The amount of mountain glaciers on the Tibetan plateau accounts for 81.6% of the total glacial volume in China, and thus they become origination of Asia's seven major rivers including the Yangtze River, Yellow River, Ganges River, Indus River, Yarlung Zangbo River, and Nujiang River. Unfortunately, with the climate warming since the 20th century, most glaciers are retreating at a rate of 7.0 percent annually. The fast rate of glacier melt has meant more water runoff from the plateau which might exacerbate soil erosion, trigger drought and lead to sandstorms and desertification in the downstream regions. Thus, quantitive estimation and understanding of these glaciers' mass balance will be helpful to long-term sustainability of agriculture and hazard mitigation and give insights into climate change. As the primary factor for the glacier ice melting, the rising temperature should be correlated with the losing ice mass in the Tibetan plateau. However, quantification of glacier mass losses has been challenged, limited by temporarily and spatially sparse measurements using conventional data types and also due to the significant variations in glaciers' melting rates from region to region, and among glaciers in the same region. Nevertheless, the particular sensitivity of mountain glaciers to climate change makes it possible to estimate their mass change rates using GRACE even though the limited resolution. GRACE observations in southeastern Alaska, Patagonia and Tibet provided independent supports for the ability of glaciers' ice loss rates there (e.g., Matsuo and Heki, 2010). Here we expected to examine the correlation between Temperature Change Rates (TCRs) and Mass Change Rates (MCRs) and thus we computed the monthly density change and obtained the yearly Density Change Rates (DCRs) in Tibetan plateau of latitudes from 27N to 38N and longitudes ranging from 75E to 103E, and compared TCRs of ground-measured temperatures at 52 stations higher than 3000m with GRACE

  6. The short term influence of aboveground biomass cover crops on C sequestration and β–glucosidase in a vineyard ground under semiarid conditions

    Directory of Open Access Journals (Sweden)

    Fernando Peregrina

    2014-10-01

    Full Text Available Tillage and semiarid Mediterranean climatic conditions accelerate soil organic matter losses in Spanish vineyards. Previous studies showed that cover crops can increase soil organic carbon (SOC in Mediterranean vineyards. The objectives of this study were to evaluate the influence of two different cover crops in the short term on soil C sequestration in a semiarid vineyard and to study the potential use of both β–glucosidase enzimatic activity (GLU and the GLU/SOC ratio in order to assess the SOC increase. The experiment was carried out in a cv. Tempranillo (Vitis vinifera L. vineyard on a Oxyaquic Xerorthent soil in Rioja winegrowing region (NE, Spain. The experimental design was established in 2009 with three treatments: conventional tillage; sown barley cover crop (Hordeum vulgare, L.; sown Persian clover cover crop (Trifolium resupinatum L.. Carbon in the aboveground biomass with each cover crop was monitored. Soil was sampled in June 2011 and June 2012, and SOC, GLU and the GLU/SOC ratio were determined. After 3 years both cover crops increased SOC at soil surface with C sequestration rates of 0.47 and 1.19 t C ha-1 yr-1 for BV and CV respectively. GLU and GLU/SOC ratio increased in both cover crops at 0-5 cm soil depth. The C sequestration rates and GLU were related to the cover crops aboveground biomass. In consequence, in semiarid vineyards under cover crops GLU could be an appropriate indicator to asses the increase of SOC and the soil quality improvement in the short-term (2-3 years.

  7. Density Functional Theory (DFT) studies on the ground state of NO3(2A '2) radical and the first triplet state of NO3+ cation

    Institute of Scientific and Technical Information of China (English)

    CAO, Xiao-Yan(曹晓燕); HONG, Gong-Yi(洪功义); WANG, Dian-Xun(王殿勋); LI, Le-Min(黎乐民); XU, Guang-Xian(徐光宪)

    2000-01-01

    Density Functional Theory (DFT) studies on the ground states (2A'2) of NO3 radical and on the ground state (1A'1) and the first triplet state (3E") of NO3+ cation provide an unambiguous prediction about their geometrical structure: the ground states of both NO3 radical and NO3+ cation have D3h symmetry and the geometrical configuration of the first triplet state 3E" of NO3+ cation has C2v symmetry. It is shown that s far as the ionization energy calculations on NO3 radical are concerned, the results are only slightly different, no mater that gradient corrections of the exchange-correlation energy are included during self-consistent iterations of they are included as perturbations after the self-consistent iterations.

  8. Inequalities of the electron density at the nucleus and radial expectation values of the ground state for the lithium isoelectronic sequence

    Institute of Scientific and Technical Information of China (English)

    陈超; 王治文

    2003-01-01

    The electron density at the nucleus,p(0),and the radtial expectation values,< rn >(-2 ≤ n ≤10),of the ground state for the lithium isoelectronic sequence are calculated with a full core plus correlation(FCPC) wavefunctions.By using these obtained expectation values,the accurate inequalities of the electron density at the nucleus and the radtial expectation values derived by Galvez and Porras for these systems are examined and verified.The final results show that FCPC wavefunctions used in this work can give satisfactory results in full configuration space.

  9. On the E-H transition in inductively coupled radio frequency oxygen plasmas: I. Density and temperature of electrons, ground state and singlet metastable molecular oxygen

    Science.gov (United States)

    Wegner, Th; Küllig, C.; Meichsner, J.

    2017-02-01

    In this series of two papers, the E-H transition in a planar inductively coupled radio frequency discharge (13.56 MHz) in pure oxygen is studied using comprehensive plasma diagnostic methods. The electron density serves as the main plasma parameter to distinguish between the operation modes. The (effective) electron temperature, which is calculated from the electron energy distribution function and the difference between the floating and plasma potential, halves during the E-H transition. Furthermore, the pressure dependency of the RF sheath extension in the E-mode implies a collisional RF sheath for the considered total gas pressures. The gas temperature increases with the electron density during the E-H transition and doubles in the H-mode compared to the E-mode, whereas the molecular ground state density halves at the given total gas pressure. Moreover, the singlet molecular metastable density reaches 2% in the E-mode and 4% in the H-mode of the molecular ground state density. These measured plasma parameters can be used as input parameters for global rate equation calculations to analyze several elementary processes. Here, the ionization rate for the molecular oxygen ions is exemplarily determined and reveals, together with the optical excitation rate patterns, a change in electronegativity during the mode transition.

  10. Accurate Ground-State Energies of Solids and Molecules from Time-Dependent Density-Functional Theory

    DEFF Research Database (Denmark)

    Olsen, Thomas; Thygesen, Kristian Sommer

    2014-01-01

    We demonstrate that ground-state energies approaching chemical accuracy can be obtained by combining the adiabatic-connection fluctuation-dissipation theorem with time-dependent densityfunctional theory. The key ingredient is a renormalization scheme, which eliminates the divergence...

  11. Inactivation of Penicillium digitatum Spores by a High-Density Ground-State Atomic Oxygen-Radical Source Employing an Atmospheric-Pressure Plasma

    Science.gov (United States)

    Iseki, Sachiko; Hashizume, Hiroshi; Jia, Fengdong; Takeda, Keigo; Ishikawa, Kenji; Ohta, Takayuki; Ito, Masafumi; Hori, Masaru

    2011-11-01

    Penicillium digitatum spores were inactivated using an oxygen-radical source that supplies only neutral oxygen radicals. Vacuum ultraviolet absorption spectroscopy was used to measure the ground-state atomic oxygen [O (3Pj)] densities and they were estimated to be in the range of 1014-1015 cm-3. The inactivation rate of P. digitatum spores was correlated with the O (3Pj) density. The result indicates that O (3Pj) is the dominant species in the inactivation. The inactivation rate constant of P. digitatum spores by O (3Pj) was estimated to be on the order of 10-17 cm3 s-1 from the measured O (3Pj) densities and inactivation rates.

  12. Impact of no-till cover cropping of Italian ryegrass on above and below ground faunal communities inhabiting a soybean field with special emphasis on soybean cyst nematodes

    Science.gov (United States)

    Two field trials were conducted in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop in a no-till soybean (Glycine max) planting to 1) reduce populations of plant-parasitic nematodes (i.e., the soybean cyst nematode, Heterodera glycines and lesion nematodes...

  13. Effects of environmental chemicals on useful insects and pests. Studies on the aluminium tolerance of some forest ground cover species. Nutz- und Schadinsekten in Abhaengigkeit von Umweltchemikalien. Aluminiumtoleranz von Waldbodenpflanzen

    Energy Technology Data Exchange (ETDEWEB)

    Albert, A.; Bogenschuetz, H.; Buecking, W.; Hradetzky, J.; Koenig, E.; Kublin, E.

    1986-01-01

    In the present issue one of four contributions deals with the aluminium tolerance of some forest ground cover species. Growth results are indicated for the forest ground cover species Poa nemoralis, Luzula luzuloides, Deschampsia flexuosa, Nardus stricta, Milium effusum and Melica uniflora as potted cultures on sand receiving nitrogen in different ratios of form and in different concentrations, the aluminium concentration being variable in the culture broths with a pH-value of 4.0. Low aluminium concentrations (10.8 mg/l Al) in the culture broths enhanced the growth of all species, some species were adversely affected and showed impaired growth (Poa nemoralis, Milium effusum, Melica uniflora) from high aluminium-ion concentrations (108 mg/l Al), but others had their best growth results - varying according to the form of nitrogen offered - only if aluminium concentrations in the culture broth were high. The species examined accumulate aluminium in their above-ground biomass to varying extents. With 21 figs., 12 tabs.

  14. Estimating spatial distribution of daily snow depth with kriging methods: combination of MODIS snow cover area data and ground-based observations

    Directory of Open Access Journals (Sweden)

    C. L. Huang

    2015-09-01

    Full Text Available Accurately measuring the spatial distribution of the snow depth is difficult because stations are sparse, particularly in western China. In this study, we develop a novel scheme that produces a reasonable spatial distribution of the daily snow depth using kriging interpolation methods. These methods combine the effects of elevation with information from Moderate Resolution Imaging Spectroradiometer (MODIS snow cover area (SCA products. The scheme uses snow-free pixels in MODIS SCA images with clouds removed to identify virtual stations, or areas with zero snow depth, to compensate for the scarcity and uneven distribution of stations. Four types of kriging methods are tested: ordinary kriging (OK, universal kriging (UK, ordinary co-kriging (OCK, and universal co-kriging (UCK. These methods are applied to daily snow depth observations at 50 meteorological stations in northern Xinjiang Province, China. The results show that the spatial distribution of snow depth can be accurately reconstructed using these kriging methods. The added virtual stations improve the distribution of the snow depth and reduce the smoothing effects of the kriging process. The best performance is achieved by the OK method in cases with shallow snow cover and by the UCK method when snow cover is widespread.

  15. A review of the developments of self-etching primers and adhesives -Effects of acidic adhesive monomers and polymerization initiators on bonding to ground, smear layer-covered teeth.

    Science.gov (United States)

    Ikemura, Kunio; Kadoma, Yoshinori; Endo, Takeshi

    2011-01-01

    This paper reviews the developments of self-etching primers and adhesives, with a special focus on the effect of acidic adhesive monomers and polymerization initiators on bonding to ground, smear layer-covered teeth. Ionized acidic adhesive monomers chemically interact with tooth substrates and facilitate good bonding to ground dentin. Polymerization initiators in self-etching primers further promote effective bonding to ground dentin. To promote bonding to both dentin and enamel, phosphonic acid monomers such as 6-methacryloyloxyhexyl phosphonoacetate (6-MHPA) were developed. These novel adhesive monomers also have a water-soluble nature and are hence endowed with sufficient demineralization capability. A new single-bottle, self-etching, 2-hydroxyethyl methacrylate (HEMA)-free adhesive comprising 6-MHPA and 4-acryloyloxyethoxycarbonylphthalic acid (4-AET) was developed. This novel adhesive enabled strong adhesion to both ground enamel and dentin, but its formulation stability was influenced by pH value of the adhesive. To develop hydrolytically stable, single-bottle, self-etching adhesives, hydrolytically stable, radical-polymerizable acidic monomers with amide or ether linkages have been developed.

  16. Absolute ground-state nitrogen atom density in a N{sub 2}/CH{sub 4} late afterglow: TALIF experiments and modelling studies

    Energy Technology Data Exchange (ETDEWEB)

    Es-sebbar, Et; C-Gazeau, M; Benilan, Y; Jolly, A [LISA, Universites Paris-Est Creteil Val de Marne (UPEC) and Paris Denis Diderot, CNRS-UMR 7583, 61, avenue du General de Gaulle, 94010 Creteil Cedex (France); Pintassilgo, C D, E-mail: essebbar@lisa.univ-paris12.f [Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal)

    2010-08-25

    Following a first study on a late afterglow in flowing pure nitrogen post discharge, we report new two-photon absorption laser-induced fluorescence (TALIF) measurements of the absolute ground-state atomic nitrogen density N({sup 4}S) and investigate the influence of methane introduced downstream from the discharge by varying the CH{sub 4} mixing ratio from 0% up to 50%. The N ({sup 4}S) maximum density is about 2.2 x 10{sup 15} cm{sup -3} in pure N{sub 2} for a residence time of 22 ms and does not change significantly for methane mixing ratio up to {approx}15%, while above, a drastic decrease is observed. The influence of the residence time has been studied. A kinetic model has been developed to determine the elementary processes responsible for the evolution of the N ({sup 4}S) density in N{sub 2}/CH{sub 4} late afterglow. This model shows the same decrease as the experimental results even though absolute density values are always larger by about a factor of 3. In the late afterglow three-body recombination dominates the loss of N ({sup 4}S) atoms whatever the CH{sub 4} mixing ratio. For high CH{sub 4} mixing ratio, the destruction process through collisions with CH{sub 3}, H{sub 2}CN and NH becomes important and is responsible for the observed decrease of the N ({sup 4}S) density.

  17. Road density

    Data.gov (United States)

    U.S. Environmental Protection Agency — Road density is generally highly correlated with amount of developed land cover. High road densities usually indicate high levels of ecological disturbance. More...

  18. Experimental differential cross sections, level densities, and spin cutoffs as a testing ground for nuclear reaction codes

    Science.gov (United States)

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Bürger, A.; Görgen, A.; Guttormsen, M.; Larsen, A. C.; Massey, T. N.; Siem, S.

    2013-11-01

    Proton double-differential cross sections from 59Co(α,p)62Ni, 57Fe(α,p)60Co, 56Fe(7Li,p)62Ni, and 55Mn(6Li,p)60Co reactions have been measured with 21-MeV α and 15-MeV lithium beams. Cross sections have been compared against calculations with the empire reaction code. Different input level density models have been tested. It was found that the Gilbert and Cameron [A. Gilbert and A. G. W. Cameron, Can. J. Phys.0008-420410.1139/p65-139 43, 1446 (1965)] level density model is best to reproduce experimental data. Level densities and spin cutoff parameters for 62Ni and 60Co above the excitation energy range of discrete levels (in continuum) have been obtained with a Monte Carlo technique. Excitation energy dependencies were found to be inconsistent with the Fermi-gas model.

  19. Development of a ground hydrology model suitable for global climate modeling using soil morphology and vegetation cover, and an evaluation of remotely sensed information

    Science.gov (United States)

    Zobler, L.; Lewis, R.

    1988-01-01

    The long-term purpose was to contribute to scientific understanding of the role of the planet's land surfaces in modulating the flows of energy and matter which influence the climate, and to quantify and monitor human-induced changes to the land environment that may affect global climate. Highlights of the effort include the following: production of geo-coded, digitized World Soil Data file for use with the Goddard Institute for Space Studies (GISS) climate model; contribution to the development of a numerical physically-based model of ground hydrology; and assessment of the utility of remote sensing for providing data on hydrologically significant land surface variables.

  20. Magnetothermopower in unconventional charge density wave ground state of α-(BEDT-TTF){_2}KHg(SCN){_4}

    Science.gov (United States)

    Dóra, B.; Maki, K.; Virosztek, A.; Ványolos, A.

    2004-04-01

    We have investigated theoretically the thermoelectric power and the Nernst effect in unconventional density waves (UDW). Due to the presence of magnetic field, Landau levels are formed, and the low energy excitations change from gapless to gapped. The present results account consistently for the recent data of magnetothermopower in α-(BEDT-TTF)2KHg(SCN)4 obtained by Choi et al. (Phys. Rev. B, 65, 205119 (2002)). This confirms further our identification of low temperature phase (LTP) in this salt as UCDW. Key words. density waves, α-(BEDT-TTF)2KHg(SCN)4, thermoelectric power.

  1. A method for the retrieval of atomic oxygen density and temperature profiles from ground-based measurements of the O(+)(2D-2P) 7320 A twilight airglow

    Science.gov (United States)

    Fennelly, J. A.; Torr, D. G.; Richards, P. G.; Torr, M. R.; Sharp, W. E.

    1991-01-01

    This paper describes a technique for extracting thermospheric profiles of the atomic-oxygen density and temperature, using ground-based measurements of the O(+)(2D-2P) doublet at 7320 and 7330 A in the twilight airglow. In this method, a local photochemical model is used to calculate the 7320-A intensity; the method also utilizes an iterative inversion procedure based on the Levenberg-Marquardt method described by Press et al. (1986). The results demonstrate that, if the measurements are only limited by errors due to Poisson noise, the altitude profiles of neutral temperature and atomic oxygen concentration can be determined accurately using currently available spectrometers.

  2. Unrestricted density functional theory based on the fragment molecular orbital method for the ground and excited state calculations of large systems

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Hiroya, E-mail: nakata.h.ab@m.titech.ac.jp [Center for Biological Resources and Informatics, Tokyo Institute of Technology, B-62 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); RIKEN, Research Cluster for Innovation, Nakamura Lab, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Fedorov, Dmitri G. [NRI, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Yokojima, Satoshi [RIKEN, Research Cluster for Innovation, Nakamura Lab, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tokyo University of Pharmacy and Life Sciences, 1423-1 Horinouchi, Hachioji-shi, Tokyo 192-0392 (Japan); Kitaura, Kazuo [Graduate School of System Informatics, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501 (Japan); Sakurai, Minoru [Center for Biological Resources and Informatics, Tokyo Institute of Technology, B-62 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); Nakamura, Shinichiro [RIKEN, Research Cluster for Innovation, Nakamura Lab, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2014-04-14

    We extended the fragment molecular orbital (FMO) method interfaced with density functional theory (DFT) into spin unrestricted formalism (UDFT) and developed energy gradients for the ground state and single point excited state energies based on time-dependent DFT. The accuracy of FMO is evaluated in comparison to the full calculations without fragmentation. Electronic excitations in solvated organic radicals and in the blue copper protein, plastocyanin (PDB code: 1BXV), are reported. The contributions of solvent molecules to the electronic excitations are analyzed in terms of the fragment polarization and quantum effects such as interfragment charge transfer.

  3. Effects of N2O and O2 addition to nitrogen Townsend dielectric barrier discharges at atmospheric pressure on the absolute ground-state atomic nitrogen density

    KAUST Repository

    Es-sebbar, Et-touhami

    2012-11-27

    Absolute ground-state density of nitrogen atoms N (2p3 4S3/2) in non-equilibrium Townsend dielectric barrier discharges (TDBDs) at atmospheric pressure sustained in N2/N2O and N2/O2 gas mixtures has been measured using Two-photon absorption laser-induced fluorescence (TALIF) spectroscopy. The quantitative measurements have been obtained by TALIF calibration using krypton as a reference gas. We previously reported that the maximum of N (2p3 4S3/2) atom density is around 3 × 1014 cm-3 in pure nitrogen TDBD, and that this maximum depends strongly on the mean energy dissipated in the gas. In the two gas mixtures studied here, results show that the absolute N (2p3 4S3/2) density is strongly affected by the N2O and O2 addition. Indeed, the density still increases exponentially with the energy dissipated in the gas but an increase in N2O and O2 amounts (a few hundreds of ppm) leads to a decrease in nitrogen atom density. No discrepancy in the order of magnitude of N (2p3 4S3/2) density is observed when comparing results obtained in N2/N2O and N2/O2 mixtures. Compared with pure nitrogen, for an energy of ∼90 mJ cm-3, the maximum of N (2p3 4S3/2) density drops by a factor of 3 when 100 ppm of N2O and O2 are added and it reduces by a factor of 5 for 200 ppm, to reach values close to our TALIF detection sensitivity for 400 ppm (1 × 1013 cm -3 at atmospheric pressure). © 2013 IOP Publishing Ltd.

  4. Safranin-O dye in the ground state. A study by density functional theory, Raman, SERS and infrared spectroscopy.

    Science.gov (United States)

    Lofrumento, C; Arci, F; Carlesi, S; Ricci, M; Castellucci, E; Becucci, M

    2015-02-25

    The analysis of ground state structural and vibrational properties of Safranin-O is presented. The experimental results, obtained by FTIR, Raman and SERS spectroscopy, are discussed in comparison to the results of DFT calculations carried out at the B3LYP/6-311+G(d,p) level of theory. The calculated spectra reproduce quite satisfactorily the experimental data. The calculated Safranin-O equilibrium structure and the assignment of the vibrational spectra are reported as well. From the changes between Raman and SERS spectra a model is presented for the interaction of Safranin-O with silver nanoparticles.

  5. Variable-density ground-water flow and paleohydrology in the Waste Isolation Pilot Plant (WIPP) region, southeastern New Mexico

    Science.gov (United States)

    Davies, P.B.

    1989-01-01

    Variable-density groundwater flow was studied near the Waste Isolation Pilot Plant in southeastern New Mexico. An analysis of the relative magnitude of pressure-related and density-related flow-driving forces indicates that density-related gravity effects are not significant at the plant and to the west but are significant in areas to the north, northeast, and south. A regional-scale model of variable-density groundwater flow in the Culebra Dolomite member of the Rustler Formation indicates that the flow velocities are relatively rapid (10 to the minus 7th power m/sec) west of the site and extremely slow (10 to the minus 11th power m/sec) east and northeast of the site. In the transition zone between those two extremes, which includes the plant, velocities are highly variable. Sensitivity simulations indicate that the central and western parts of the region, including the plant, are fairly well isolated from the eastern and northeastern boundaries. Vertical-flux simulations indicate that as much as 25% of total inflow to the Culebra could be entering as vertical flow, with most of this flow occurring west of the plant. A simple cross-sectional model was developed to examine the flow system as it drains through time following recharge during a past glacial pluvial. This model indicates that the system as a whole drains very slowly and that it apparently could have sustained flow from purely transient drainage following recharge of the system during the Pleistocene. (USGS)

  6. Octupole deformation in the ground states of even-even nuclei: a global analysis within the covariant density functional theory

    CERN Document Server

    Agbemava, S E; Ring, P

    2016-01-01

    A systematic investigation of octupole deformed nuclei is presented for even-even systems with $Z\\leq 106$ located between the two-proton and two-neutron drip lines. For this study we use five most up-to-date covariant energy density functionals of different types, with a non-linear meson coupling, with density dependent meson couplings, and with density-dependent zero-range interactions. Pairing correlations are treated within relativistic Hartree-Bogoliubov (RHB) theory based on an effective separable particle-particle interaction of finite range. This allows us to assess theoretical uncertainties within the present covariant models for the prediction of physical observables relevant for octupole deformed nuclei. In addition, a detailed comparison with the predictions of non-relativistic models is performed. A new region of octupole deformation, centered around $Z\\sim 98, N\\sim 196$ is predicted for the first time. In terms of its size in the $(Z,N)$ plane and the impact of octupole deformation on binding e...

  7. Are growth and density quantitative indicators of essential fish habitat quality? An application to the common sole Solea solea nursery grounds

    Science.gov (United States)

    Gilliers, C.; Le Pape, O.; Désaunay, Y.; Morin, J.; Guérault, D.; Amara, R.

    2006-08-01

    Bio-indicators were measured on juvenile fish to assess the quality of eight coastal and estuarine nursery grounds in the Eastern English Channel and in the Bay of Biscay during 3 years. Growth (size and otolith daily increment width), body condition (morphometric index) and abundance of juvenile common soles were analysed together with xenobiotic concentrations (heavy metals and organic contaminants). Condition indices displayed important variations and did not allow relevant estimation of environmental quality. On the contrary, growth and density indicators showed good steadiness above years but varied among sites. In spite of difficulties of interpreting these indicators on such a meso-scale approach, analyses highlighted the estuaries of Seine and Gironde. In these nursery areas, the levels of contamination were especially high, and the combination of fish growth performances and density was significantly lower than in other sites. The combination of these variables appears to provide reliable indicators of habitat quality and anthropogenic pressure on nursery grounds, especially highlighting contaminated areas. Such indicators may thus contribute to improve assessment of environmental quality of essential fish habitats with the aim of a sustainable management of fisheries resources. A study at a different scale, from this meso-scale nursery approach with more precise analyses, on local habitats, will nevertheless be necessary to optimize the relevance of these indicators for the assessment of essential fish habitat quality.

  8. Land Cover

    Data.gov (United States)

    Kansas Data Access and Support Center — The Land Cover database depicts 10 general land cover classes for the State of Kansas. The database was compiled from a digital classification of Landsat Thematic...

  9. Fourier-Legendre expansion of the one-electron density-matrix of ground-state two-electron atoms

    OpenAIRE

    Ragot, Sebastien; Ruiz, Maria Belen

    2009-01-01

    The density-matrix rho(r, r') of a spherically symmetric system can be expanded as a Fourier-Legendre series of Legendre polynomials Pl(cos(theta) = r.r'/rr'). Application is here made to harmonically trapped electron pairs (i.e. Moshinsky's and Hooke's atoms), for which exact wavefunctions are known, and to the helium atom, using a near-exact wavefunction. In the present approach, generic closed form expressions are derived for the series coefficients of rho(r, r'). The series expansions are...

  10. Properties of the single-site reduced density matrix in the Bose-Bose resonance model in the ground state and in quantum quenches

    Science.gov (United States)

    Dorfner, F.; Heidrich-Meisner, F.

    2016-06-01

    We study properties of the single-site reduced density matrix in the Bose-Bose resonance model as a function of system parameters. This model describes a single-component Bose gas with a resonant coupling to a diatomic molecular state, here defined on a lattice. A main goal is to demonstrate that the eigenstates of the single-site reduced density matrix have structures that are characteristic for the various quantum phases of this system. Since the Hamiltonian conserves only the global particle number but not the number of bosons and molecules individually, these eigenstates, referred to as optimal modes, can be nontrivial linear combinations of bare eigenstates of the molecular and boson particle number. We numerically analyze the optimal modes and their weights, the latter giving the importance of the corresponding state, in the ground state of the Bose-Bose resonance model. We find that the single-site von Neumann entropy is sensitive to the location of the phase boundaries. We explain the structure of the optimal modes and their weight spectra using perturbation theory and via a comparison to results for the single-component Bose-Hubbard model. We further study the dynamical evolution of the optimal modes and of the single-site entanglement entropy in two quantum quenches that cross phase boundaries of the model and show that these quantities are thermal in the steady state. For our numerical calculations, we use the density-matrix renormalization group method for ground-state calculations and time evolution in a Krylov subspace for the quench dynamics as well as exact diagonalization.

  11. 9种多年生地被植物在华北高寒区的抗寒性%Study on Cold -resistance of Several Ground Cover Plants in the Cold Plateau of North China

    Institute of Scientific and Technical Information of China (English)

    张晓磊; 马建平; 宋国亮; 李欣儒; 张立峰

    2012-01-01

    The study with introduced ground cover plants as meterials. Through observations on their natural growth conditions and growth morphology and demonstration tests of artificial low-temperature stress root cold physiological changes and physical growth of strain recovery validation studies, the results showed that 0 - -18℃ low temperature processing, the relative conductivity, soluble sugar and praline contents of nine perennial ground cover plants were all on the rise, while in the - 18- - 36℃ processing, soluble sugar and free proline content of Platycodon grandiforus. Hemerocallis stella remained rise after fall. The Hosta plantaginea, Aster novibelgii, Lilium brownii var. viridulum showed continuous downward trend. Combination of winter cold stress, sexual and physical strain to restore growth status showed that nine perennial ground cover plants could be successful overwintering in north China. Basis of resistance to the cold, the orders were Platycodon grandiforus 〉 HemerocaUis stella 〉 Hemerocallis middenclorffii 〉 Paeonia lactiflora 〉 P. lactiflora 〉 Sedum spectabile 〉 Hosta plantaginea 〉 Lilium brownii var. viridulum.%以引种的9种多年生地被植物为材料,通过对其在华北高寒区自然生长条件下的越冬性与生长形态观测,以及人工低温胁迫下根系抗寒生理指标变化与株体生长恢复的实证研究表明,0-18℃处理温段,9种地被植物的相对电导率、可溶性糖和游离脯氨酸含量均呈上升趋势;在-18--6℃处理温段,桔梗、金娃娃萱草可溶性搪和游离脯氨酸含量仍保持上升而后再下降,而玉椿、荷兰菊、百合则呈持续下降趋势。结合越冬性与低温胁迫下株体恢复生长状况认为,9种地被植物在华北高寒区常年环境下均可越冬,其抗寒能力依次为:桔梗〉金娃娃萱草〉大花萱草〉单瓣芍药〉重瓣芍药〉八宝景天〉玉簪〉荷兰菊〉百合。

  12. 氯盐融雪剂对4种地被植物种子萌发的影响%Effect of chloride deicing salts on seed germination of four ground covers species

    Institute of Scientific and Technical Information of China (English)

    杨冬; 周广柱

    2015-01-01

    The effects of deicing salts on seed germination and growth of shoots and roots of four kinds of ground covers (Poa pratensts, Bromus inermis Layss,Coreopsis basalis,Cosmos bipinnatus Cav. ) were studied. The length of roots and shoots of ground covers were also determined in this paper. The results showed that the inhibition effect on seed germination and growth response in the four kinds of ground covers was increased with increasing concentration of deicing salts. Cosmos bipinnatus Cav.showed the highest tolerance to deicing salts, followed by Bromus inermis Layss, Coreopsis basalis and Poa pratensis. The critical value of tolerance to deicing salts were 14.69 g/L, 10.04 g/L, 7.38 g/L and 7.31 g/L forCosmos bipinnatus Cav, Bromus inermis Layss, Coreopsis basalis and Poa pratensis,respectively and the maximum value were 21.08 g/L, 16.51 g/L, 14.67 g/L and 13.50 g/L, respectively.%以草地早熟禾、无芒雀麦、金鸡菊、波斯菊4种地被植物种子为研究材料,探讨不同浓度氯盐类融雪剂对其发芽的影响。结果表明:随着融雪剂浓度的增加,4种地被植物种子萌发、幼芽、幼根生长受到的抑制作用增强。4种地被植物对融雪剂胁迫的耐受能力大小依次为波斯菊>无芒雀麦>金鸡菊>草地早熟禾,耐受临界值分别为14.69 g/L、10.04 g/L、7.38 g/L和7.31 g/L,极限值分别为21.08 g/L、16.51 g/L、14.67 g/L和13.50 g/L。

  13. Land Use and Land Cover, WI Agricultural Statistics Service (WASS) WI Cropland Data Layer. Agriculture and non-ag land cover categories based on survey data (ground truth), satellite imagery classification, FSA common land unit, and 2001 National Land Cover dataset., Published in 2008, 1:100000 (1in=8333ft) scale, Wisconsin Department of Agriculture, Trade & Consumer Protection.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Land Use and Land Cover dataset, published at 1:100000 (1in=8333ft) scale, was produced all or in part from Field Observation information as of 2008. It is...

  14. Efficient evaluation of dielectric response functions and calculations of ground and excited state properties beyond local Density Functional approaches

    Science.gov (United States)

    Lu, Deyu; Li, Yan; Rocca, Dario; Viet Nguyen, H.; Gygi, Francois; Galli, Giulia

    2010-03-01

    A recently developed technique to diagonalize iteratively dielectric matrices [1], is used to carry out efficient, ab-initio calculations of dispersion interactions, and excited state properties of nanostructures. In particular, we present results for the binding energies of weakly bonded molecular crystals [2], obtained at the EXX/RPA level of theory, and for absorption spectra of semiconducting clusters, obtained by an iterative solution of the Bethe-Salpeter equations [3]. We show that the ability to obtain the eigenmodes of dielectric matrices from Density Functional perturbation theory, without computing single particle excited states, greatly improves the efficiency of both EXX/RPA and many body perturbation theory [3,4] calculations and opens the way to large scale computations. [1] H. Wilson, F. Gygi and G. Galli, Phys. Rev. B , 78, 113303, 2008; and H. Wilson, D. Lu, F. Gygi and G. Galli, Phys. Rev. B, 79, 245106, 2009. [2] D. Lu, Y. Li, D. Rocca and G. Galli, Phys. Rev. Lett, 102, 206411, 2009; and Y. Li, D. Lu, V. Nguyen and G. Galli, J. Phys. Chem. C (submitted) [3] D. Rocca, D. Lu and G. Galli, submitted. [4] D. Lu, F. Gygi and G. Galli, Phys. Rev. Lett. 100, 147601, 2008. Work was funded by DOE/Scidac DE-FC02-06ER25794 and DOE/BES DE-FG02-06ER46262.

  15. Argument for charge density wave sub-phases in the ground state of α-(BEDT-TTF) 2KHg(SCN) 4

    Science.gov (United States)

    Biskup, N.; Perenboom, J. A. A. J.; Brooks, J. S.; Qualls, J. S.

    1998-07-01

    A resistive anomaly at temperature Tp in the title compound is associated with a Fermi surface reconstruction from a metallic to a (spin or charge) density wave state. At high magnetic fields a corresponding feature in the magnetoresistance above a field BK indicates the breaking of this state. We argue that TP indicates a second order phase line identical to that measured by specific heat methods and show that it decreases monotonically up to 30T. We find that Pauli (rather than orbital) effects, dominate the reduction in Tp. We further argue that BK is a first-order transition between two subphases below Tp. We compare the phase diagram with recent theoretical models for CDW and SDW ground states in high magnetic fields.

  16. Evaluation of bone-to-implant contact and bone density adjacent to titanium implants using a stereological technique on ground sections

    DEFF Research Database (Denmark)

    Balatsouka, Dimitra; Gotfredsen, Klaus; Gundersen, Hans Jørgen Gottlieb

    2006-01-01

    using stereological principles. The aim of the study was to describe an unbiased design for evaluating boneto- implant contact (BIC) and peri-implant bone density (BD-i) in three-dimensions. The unbiased design was based on a fixed axis vertical random sampling technique. Three bone-implant blocks were...... collected from 3 rabbits. Four sections were obtained from each animal using a fixed axis vertical random sampling technique. The BIC was estimated by creating a stereological method based on a systematic test line set. The BD-i was estimated using a design based on a systematic point set. The efficiency......When bone implants have to be examined in situ ground sections are required. Histomorphometric measurements are usually performed on two-dimensional sections, causing biased results when they are wrongly extrapolated to 3D without any knowledge of stereology. Unbiased results can only be obtained...

  17. Validation of SCIAMACHY NO2 Vertical Column Densities with Mt.Cimone and Stara Zagora Ground-Based Zenith Sky DOAS Observations

    Science.gov (United States)

    Kostadinov, I.; Petritoli, A.; Werner, R.; Valev, D.; Atanasov, At.; Bortoli, D.; Markova, T.; Ravegnani, F.; Palazzi, E.; Giovanelli, G.

    2004-08-01

    Ground-based zenith sky Differential Optical Absorption Spectroscopy (DOAS) measurements performed by means of GASCOD instruments at Mt. Cimone (44N 11E), Italy and Stara Zagora (42N, 25E), Bulgaria are used for validation of SCIAMACHY NO2 vertical column density (vcd) of ESA SCI_NL product retrieved with 5.01 processor version. The results presented in this work regard satellite data for the JulyDecember 2002 period. On this base it is concluded that during summer-autumn period the overall NO2 vcd above both stations is fairly well reproduced by the SCIAMACHY data, while towards the winter period they deviate from the seasonal behaviour of NO2 vcd derived at both stations

  18. Evaluation of bone-to-implant contact and bone density adjacent to titanium implants using a stereological technique on ground sections

    DEFF Research Database (Denmark)

    Balatsouka, Dimitra; Gotfredsen, Klaus; Gundersen, Hans Jørgen Gottlieb

    2006-01-01

    When bone implants have to be examined in situ ground sections are required. Histomorphometric measurements are usually performed on two-dimensional sections, causing biased results when they are wrongly extrapolated to 3D without any knowledge of stereology. Unbiased results can only be obtained...... using stereological principles. The aim of the study was to describe an unbiased design for evaluating boneto- implant contact (BIC) and peri-implant bone density (BD-i) in three-dimensions. The unbiased design was based on a fixed axis vertical random sampling technique. Three bone-implant blocks were...... collected from 3 rabbits. Four sections were obtained from each animal using a fixed axis vertical random sampling technique. The BIC was estimated by creating a stereological method based on a systematic test line set. The BD-i was estimated using a design based on a systematic point set. The efficiency...

  19. Effect of the density of transplants in reforestation on the morphological quality of the above-ground part of European beech (Fagus sylvatica L. six years after planting

    Directory of Open Access Journals (Sweden)

    Kateřina Houšková

    2013-01-01

    Full Text Available Quality of the above-ground part of European beech planted at different densities and spacing patterns for the purpose of artificial forest regeneration was monitored 3, 4 and 6 years after planting. The initial numbers of beech transplants were 5,000 pcs.ha−1, 10,000 pcs.ha−1, 15,000 pcs.ha−1 and 20,000 pcs.ha−1. The spacing pattern of transplants was either square or rectangular nearly in all variants: 1.4 × 1.4 m, 2 × 1 m, 1 × 1 m, 0.8 × 0.8 m, 1 ×0.65 m, 0.7 × 0.7 m and 1 × 0.5 m. Conclusions following out from the research are as follows: 1. neither the chosen density of transplants nor their spacing pattern had an essential influence on the after-planting loss or damage of trees; 2. through the planting of larger-diameter transplants it is possible to achieve canopy closure more rapidly as well as faster growth of the plantation; these beech plants keep the edge in growth and quality even 6 years after planting; 3. the higher is the beech plantation density, the less individuals occur in such a plantation with inappropriate stem form; 4. beech plants of the worst quality were found on plots with the lowest initial density of transplants (5,000 and 10,000 pcs.ha−1, yet the number of promising trees was sufficient even there. Thus, none of the experimental numbers of transplants per hectare or spacing arrangements of the European beech transplants can be claimed as inappropriate; however, further monitoring of the plots is necessary.

  20. Density Optimization of Lithium Lanthanum Titanate Ceramics for Lightweight Lithium-Air Batteries

    Science.gov (United States)

    2014-11-01

    Density Optimization of Lithium Lanthanum Titanate Ceramics for Lightweight Lithium -Air Batteries by Claire Weiss Brennan, Victoria Blair...Ground, MD 21005-5069 ARL-TR-7145 November 2014 Density Optimization of Lithium Lanthanum Titanate Ceramics for Lightweight Lithium -Air...COVERED (From - To) 1 June–31 August 2014 4. TITLE AND SUBTITLE Density Optimization of Lithium Lanthanum Titanate Ceramics for Lightweight Lithium

  1. SUTRA: A model for 2D or 3D saturated-unsaturated, variable-density ground-water flow with solute or energy transport

    Science.gov (United States)

    Voss, Clifford I.; Provost, A.M.

    2002-01-01

    SUTRA (Saturated-Unsaturated Transport) is a computer program that simulates fluid movement and the transport of either energy or dissolved substances in a subsurface environment. This upgraded version of SUTRA adds the capability for three-dimensional simulation to the former code (Voss, 1984), which allowed only two-dimensional simulation. The code employs a two- or three-dimensional finite-element and finite-difference method to approximate the governing equations that describe the two interdependent processes that are simulated: 1) fluid density-dependent saturated or unsaturated ground-water flow; and 2) either (a) transport of a solute in the ground water, in which the solute may be subject to: equilibrium adsorption on the porous matrix, and both first-order and zero-order production or decay; or (b) transport of thermal energy in the ground water and solid matrix of the aquifer. SUTRA may also be used to simulate simpler subsets of the above processes. A flow-direction-dependent dispersion process for anisotropic media is also provided by the code and is introduced in this report. As the primary calculated result, SUTRA provides fluid pressures and either solute concentrations or temperatures, as they vary with time, everywhere in the simulated subsurface system. SUTRA flow simulation may be employed for two-dimensional (2D) areal, cross sectional and three-dimensional (3D) modeling of saturated ground-water flow systems, and for cross sectional and 3D modeling of unsaturated zone flow. Solute-transport simulation using SUTRA may be employed to model natural or man-induced chemical-species transport including processes of solute sorption, production, and decay. For example, it may be applied to analyze ground-water contaminant transport problems and aquifer restoration designs. In addition, solute-transport simulation with SUTRA may be used for modeling of variable-density leachate movement, and for cross sectional modeling of saltwater intrusion in

  2. Ground-state magnetic structure of hexagonal YMnO3 compound: A non-collinear spin density functional theory study

    Science.gov (United States)

    Lima, A. F.; Lalic, M. V.

    2016-10-01

    With objective to determine ground state magnetic structure of multiferroic hexagonal YMnO3 we performed systematic non-collinear spin density-functional-theory (DFT) study of six possible magnetic configurations of Mn ions, treating exchange and correlation effects by standard local-spin-density approximation (LSDA), by LSDA including Hubbard correction (LSDA+U), and taking into account the spin-orbit interaction. We found that P63 and P6´3 configurations are the most stable ones, with very small energy difference between them. This result substantiates conclusions of latest neutron-diffraction studies. Both configurations are characterized by canting of Mn spins that produces weak ferro- (P63) or anti-ferromagnetism (P6‧3) along the hexagonal c-axis. The calculated Mn magnetic moments are found to be in good agreement with experiment, and electronic structure generally agrees with previous non-collinear spin DFT studies that used different basis sets and exchange and correlation functionals.

  3. Effects of ground cover on the niches of main insect pests and their natural enemies in peach orchard%桃园生草对桃树上主要害虫及天敌生态位的影响

    Institute of Scientific and Technical Information of China (English)

    万年峰; 季香云; 蒋杰贤; 淡家贵

    2011-01-01

    调查了种植白三叶草桃园(生草区)与不种草桃园(对照区)桃树上主要害虫及天敌数量,并对其生态位进行了测定.结果表明:生草区桃树害虫的水平生态位、垂直生态位和时间生态位宽度最大的分别是桃红颈天牛(0.999)、茶翅蝽(0.964)和茶翅蝽(0.795),而对照区其值分别是0.918、0.792和0.632;生草区桃树天敌的水平生态位、垂直生态位和时间生态位宽度最大的都是蜘蛛,分别为0.996、0.983和0.932,而在对照区其值分别是0.900、0.800和0.818;生草区桃树害虫的三维生态位宽度依次为茶翅蝽>叶蝉>蜡蝉>桃蚜>桃潜叶蛾>桃蛀螟>桃红颈天牛>梨小食心虫>桑白蚧,而对照区为桃蚜>叶蝉>茶翅蝽>桃红颈天牛>梨小食心虫>蜡蝉>桑白蚧>桃潜叶蛾>桃蛀螟;生草区桃树天敌的三维生态位宽度为蜘蛛>小花蝽>草蛉>寄生蜂>瓢虫>食蚜蝇,而对照区为蜘蛛>草蛉>瓢虫>寄生蜂>小花蝽>食蚜蝇;对照区小花蝽、瓢虫、食蚜蝇、寄生蜂均有推迟活动迹象;生草区小花蝽与害虫的三维生态位重叠值都比相应的对照区大,天敌与害虫在时间上的同步性和空间上的同域性总体优于对照区.%Taking the peach orchards with and without ground cover Trifolium repens as test ob jects, an investigation was made on the quantities of main insect pests and their natural enemies on peach trees, with the niches of the insect pests and natural enemies measured. Among the main msect pests, Aromia bungii in the peach orchard with ground cover T. repens had the widest horizontal niche breadth ( 0. 999) , Halyomorpha halys had the widest vertical niche breadth ( 0. 964 ) and widest time niche breadth (0. 795 ) , while the corresponding values in the orchard without T. repens were 0. 918, 0. 792, and 0. 632, respectively. Among the natural enemies, spiders in the peach orchard with ground cover T. repens had the widest

  4. Benthic Cover

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic cover (habitat) maps are derived from aerial imagery, underwater photos, acoustic surveys, and data gathered from sediment samples. Shallow to moderate-depth...

  5. The thermal structure of the Venus atmosphere: Intercomparison of Venus Express and ground based observations of vertical temperature and density profiles✰

    Science.gov (United States)

    Limaye, Sanjay S.; Lebonnois, Sebastien; Mahieux, Arnaud; Pätzold, Martin; Bougher, Steven; Bruinsma, Sean; Chamberlain, Sarah; Clancy, R. Todd; Gérard, Jean-Claude; Gilli, Gabriella; Grassi, Davide; Haus, Rainer; Herrmann, Maren; Imamura, Takeshi; Kohler, Erika; Krause, Pia; Migliorini, Alessandra; Montmessin, Franck; Pere, Christophe; Persson, Moa; Piccialli, Arianna; Rengel, Miriam; Rodin, Alexander; Sandor, Brad; Sornig, Manuela; Svedhem, Håkan; Tellmann, Silvia; Tanga, Paolo; Vandaele, Ann C.; Widemann, Thomas; Wilson, Colin F.; Müller-Wodarg, Ingo; Zasova, Ludmila

    2017-09-01

    The Venus International Reference Atmosphere (VIRA) model contains tabulated values of temperature and number densities obtained by the experiments on the Venera entry probes, Pioneer Venus Orbiter and multi-probe missions in the 1980s. The instruments on the recent Venus Express orbiter mission generated a significant amount of new observational data on the vertical and horizontal structure of the Venus atmosphere from 40 km to about 180 km altitude from April 2006 to November 2014. Many ground based experiments have provided data on the upper atmosphere (90-130 km) temperature structure since the publication of VIRA in 1985. The "Thermal Structure of the Venus Atmosphere" Team was supported by the International Space Studies Institute (ISSI), Bern, Switzerland, from 2013 to 2015 in order to combine and compare the ground-based observations and the VEx observations of the thermal structure as a first step towards generating an updated VIRA model. Results of this comparison are presented in five latitude bins and three local time bins by assuming hemispheric symmetry. The intercomparison of the ground-based and VEx results provides for the first time a consistent picture of the temperature and density structure in the 40 km-180 km altitude range. The Venus Express observations have considerably increased our knowledge of the Venus atmospheric thermal structure above ∼40 km and provided new information above 100 km. There are, however, still observational gaps in latitude and local time above certain regions. Considerable variability in the temperatures and densities is seen above 100 km but certain features appear to be systematically present, such as a succession of warm and cool layers. Preliminary modeling studies support the existence of such layers in agreement with a global scale circulation. The intercomparison focuses on average profiles but some VEx experiments provide sufficient global coverage to identify solar thermal tidal components. The differences

  6. Acoustic Characterization of Grass-cover Ground

    Science.gov (United States)

    2014-11-20

    for noise and rever- beration control. Examples of porous media are cements, ceramics, rocks, building insulation , foams and soil. Characterizing the... air is consid- ered as lossless fluid and Eqs. 2.1 and 2.2 can be applied without approximations. However, when acoustic waves travel in narrow...3.1) In Eq. 3.1, P1 and P2 are the acoustic pressures measured at each respective microphone, Pi is the incident pressure, k0 is wave number in air , ω

  7. Ground-based observations of Saturn's auroral ionosphere over three days: Trends in H3+ temperature, density and emission with Saturn local time and planetary period oscillation

    Science.gov (United States)

    O'Donoghue, James; Melin, Henrik; Stallard, Tom S.; Provan, G.; Moore, Luke; Badman, Sarah V.; Cowley, Stan W. H.; Baines, Kevin H.; Miller, Steve; Blake, James S. D.

    2016-01-01

    On 19-21 April 2013, the ground-based 10-m W.M. Keck II telescope was used to simultaneously measure H3+ emissions from four regions of Saturn's auroral ionosphere: (1) the northern noon region of the main auroral oval; (2) the northern midnight main oval; (3) the northern polar cap and (4) the southern noon main oval. The H3+ emission from these regions was captured in the form of high resolution spectral images as the planet rotated. The results herein contain twenty-three H3+ temperatures, column densities and total emissions located in the aforementioned regions - ninety-two data points in total, spread over timescales of both hours and days. Thermospheric temperatures in the spring-time northern main oval are found to be cooler than their autumn-time southern counterparts by tens of K, consistent with the hypothesis that the total thermospheric heating rate is inversely proportional to magnetic field strength. The main oval H3+ density and emission is lower at northern midnight than it is at noon, in agreement with a nearby peak in the electron influx in the post-dawn sector and a minimum flux at midnight. Finally, when arranging the northern main oval H3+ parameters as a function of the oscillation period seen in Saturn's magnetic field - the planetary period oscillation (PPO) phase - we see a large peak in H3+ density and emission at ∼115° northern phase, with a full-width at half-maximum (FWHM) of ∼44°. This seems to indicate that the influx of electrons associated with the PPO phase at 90° is responsible at least in part for the behavior of all H3+ parameters. A combination of the H3+ production and loss timescales and the ±10° uncertainty in the location of a given PPO phase are likely, at least in part, to be responsible for the observed peaks in H3+ density and emission occurring at a later time than the peak precipitation expected at 90° PPO phase.

  8. Effects of Different Concentrations of Gibberellin on the Flowering of Ground-cover Chrysanthemum 'Zichonglou'%不同浓度赤霉素对地被菊‘紫重楼’开花特性的影响

    Institute of Scientific and Technical Information of China (English)

    王媛; 崔雁汇; 孔一昌; 张强; 吕晋慧

    2012-01-01

    The effects of different concentrations of gibberellin on plant height, crown breadth, flowering characteristic (flowering season, flower number, petals number, flower diameter) and the pollen germination viability of ground-cover Chrysanthemum ' Zichonglou' were studied, which could provided substantial base for the hybrid breeding and regulating flower season of ground-cover Chrysanthemum. The results showed that 100-500 mg/L of gibberellin might cause the dewing color season 6-10 days ahead of time, the starting flower season 7-12 days ahead of time, and the abundant flowering season 2-7 days ahead of time. With the increase of gibberellin concentration ranging from 0 to 500 mg/L, internode and plant height were increased, but the flower number, petals number, crown breadth, and flower diameter were inhibited. The longest internode and plant height occurred with 500 mg/L gibberellin treatment. The pollen germination viability were improved by 100-300 mg/L of gibberellin, and impressed by 500 mg/L gibberellin.%笔者探讨不同浓度赤霉素(GA3)对地被菊‘紫重楼’株高、冠幅、开花特性(花期、开花量、花朵重瓣性、花径)和花粉生活力的影响,旨在为地被菊杂交育种、花期调控提供参考依据.试验结果表明,喷施100~500 mg/L GA3后,‘紫重楼’露色期、始花期及盛花期分别提前6~10天、7~12天和2~7天;GA3有利于节间伸长和株高增加,但植株开花量和花瓣重瓣性降低,冠幅、花径减小.其中,500 mg/L GA3处理下的地被菊节间长度与株高显著高于其他水平;100~300 mg/L GA3处理可促进花粉生活力,500 mg/L对花粉生活力有抑制作用.

  9. Effect of intercropping wheat with forage legumes on wheat production and ground cover Efeito do consórcio entre trigo e leguminosas forrageiras na produção de trigo e na cobertura de solo

    Directory of Open Access Journals (Sweden)

    Gilberto Omar Tomm

    2001-03-01

    Full Text Available The use of winter legumes in southern Brazil is hindered by the slow growth of these species during establishment exposing soil surface to erosion. Introduction of these species along with spring wheat (Triticum aestivum L. was studied as a means of increasing ground cover during their initial establishment period, without reducing wheat grain yield. Two experiments were conducted in nearby areas, one in each year. Birdsfoot trefoil (Lotus corniculatus L., red clover (Trifolium pratense L. cultivar Quiñequelli, white clover (T. repens L., and arrowleaf clover (T. vesiculosum Savi did not reduce cereal yield in either year. Wheat yield was reduced by intercropped red clover cultivar Kenland and by subclover (T. subterraneum L. in the first year. No grain yield differences due to intercropping with any legume were detected in the second year, when rainfall was below normal. Intercropping with wheat showed to be a practical alternative to enhance ground cover at establishing forage legumes.O uso de leguminosas forrageiras no sul do Brasil é dificultado pelo lento crescimento dessas espécies no ano de estabelecimento, o que expõe o solo à erosão. Estudou-se a introdução dessas leguminosas concomitantemente ao trigo (Triticum aestivum L. com o objetivo de aumentar a cobertura de solo durante o seu desenvolvimento inicial, sem reduzir o rendimento de grãos de trigo. Foram realizados dois experimentos em áreas próximas, um em cada ano. O cornichão (Lotus corniculatus L., o trevo-vermelho (Trifolium pratense L., cultivar Quiñequelli, o trevo-branco (T. repens L. e o trevo-vesiculoso (T. vesiculosum Savi não reduziram o rendimento de trigo em nenhum dos anos. O rendimento de grãos de trigo foi reduzido pelo trevo-vermelho, cultivar Kenland, e pelo trevo subterrâneo (T. subterraneum L., no primeiro ano. No segundo ano, em que, durante o período de desenvolvimento de trigo, a precipitação pluvial foi inferior à normal, não se

  10. Study on Water Adaptability of Seven Common Species of Ground Cover Plants in South China%华南地区7种常见园林地被植物水分适应性研究

    Institute of Scientific and Technical Information of China (English)

    钱瑭璜; 雷江丽; 庄雪影

    2012-01-01

    Water adaptability of seven common ground cover plants in South China were studied by pot experiment. The effect of biomass increment, root-crown ratio, florescence, diurnal variations of net photosynthetic rate and diurnal variations of net transpiration rate were determined in different soil water content. The experimental results showed that 7 ground cover plants could grow strongly in the soil w ith the water holding rate above 70% to 75%. Schefflera arboricola, Rhoeo discolor (L'He'rit.) Hance and Syngonium podophyllum Schott 'White Butterfly' could grow well and possess good ornamental value in the soil with minimum water holding rates of 30% to 35%; lxora coccinea L., Excoecaria cochinchinensis, Hymenocallis littoralis and Nephrolepis auriculata could grow well in the soil with minimum water holding rates of 50% to 55%.%以华南地区7种常见园林地被植物为研究对象,通过盆栽控水试验研究,综合比较了不同水分条件下植株的生长量、根冠比、花期、花量、净光合速率日变化、净蒸腾速率日变化等生长及光合指标的变化趋势.结果表明:1)在水分条件下限为土壤持水率的70%~75%时,7种参试植物均有较旺盛的生长势;2)在满足各参试植物园林观赏性的前提下,鹅掌藤(Schefflera arboricola)、蚌花[Rhoeo discolor (L’Hérit.)Hance]和[白蝶合果芋(Syngonium podophyllum Schott ‘White Butterfly’)在水分条件下限为土壤持水率的30%~35%时可以正常生长;而红花龙船化(Ixora coceinea L.)、红背桂(Excoecaria cochinchinensis)、水鬼蕉(Hymenocallis littoralis)和肾蕨(Nephrolepis auriculata)在水分条件下限为土壤持水率的50%~55%时可以正常生长.

  11. Study on Introduction and Cultivation Techniques of Four Color--leafed Plants of Ground Cover%四种地被类彩叶植物引种栽培技术研究

    Institute of Scientific and Technical Information of China (English)

    王太平

    2011-01-01

    对引进的4个地被类植物优良品种进行了引种试验,结果表明:红叶石楠和金森女贞在高度生长和冠幅增长方面优势明显,其次为红花檀木、洒金珊瑚;栽培试验表明:4个地被类植物经过几个生长期的栽培试验,形成了一套较完整的栽培技术措施,为4个优良品种的推广应用提供了技术保障。%In this paper, four species of ground cover were studied through introduction experiment and cul- tivation experiment. The results of introduction experiment show that Photinia serru alta and Ligustrum japonicum 'Howardii" have clear advantages on high-growth and crown-growth, followed by Lorpetalum Chinese Oliv. var. rubrum Yieh and Var. variegata D'ombr. The results of cultivation experiment show that after the experiment of several growth periods, a complete cultivation technique of these four species has been formed,which provides technical support for applying these four fine varieties.

  12. EVALUATION OF BONE-TO-IMPLANT CONTACT AND BONE DENSITY ADJACENT TO TITANIUM IMPLANTS USING A STEREOLOGICAL TECHNIQUE ON GROUND SECTIONS

    Directory of Open Access Journals (Sweden)

    Dimitra Balatsouka

    2011-05-01

    Full Text Available When bone implants have to be examined in situ ground sections are required. Histomorphometric measurements are usually performed on two-dimensional sections, causing biased results when they are wrongly extrapolated to 3D without any knowledge of stereology. Unbiased results can only be obtained using stereological principles. The aim of the study was to describe an unbiased design for evaluating boneto-mplant contact (BIC and peri-implant bone density (BD-i in three-dimensions. The unbiased design was based on a fixed axis vertical random sampling technique. Three bone-implant blocks were collected from 3 rabbits. Four sections were obtained from each animal using a fixed axis vertical random sampling technique. The BIC was estimated by creating a stereological method based on a systematic test line set. The BD-i was estimated using a design based on a systematic point set. The efficiency of the systematic sampling was evaluated for each sampling level: Coefficient of error CE( i w for the systematic test line set, CESyst between the 4 rotated sections, CENoise for the reproducibility. These variances were compared to the biological variation (CV between animals. The mean CE( i w was 5 to 6%; the CESyst was 7.8% for the BIC estimates and 5.7% for the BD-i estimates; the CENoise was 5.8% for the BIC and 7.7% for the BD-i. The CV was 19% for the BIC estimates and 24% for the BD-i estimates. These results demonstrated that the stereological technique used in the present study was a very efficient method to obtain unbiased estimates of BIC and BD-i in 3D on 2D implant-bone sections.

  13. Self-organization of dislocation-free, high-density, vertically aligned GaN nanocolumns involving InGaN quantum wells on graphene/SiO2 covered with a thin AlN buffer layer.

    Science.gov (United States)

    Hayashi, Hiroaki; Konno, Yuta; Kishino, Katsumi

    2016-02-05

    We demonstrated the self-organization of high-density GaN nanocolumns on multilayer graphene (MLG)/SiO2 covered with a thin AlN buffer layer by RF-plasma-assisted molecular beam epitaxy. MLG/SiO2 substrates were prepared by the transfer of CVD graphene onto thermally oxidized SiO2/Si [100] substrates. Employing the MLG with an AlN buffer layer enabled the self-organization of high-density and vertically aligned nanocolumns. Transmission electron microscopy observation revealed that no threading dislocations, stacking faults, or twinning defects were included in the self-organized nanocolumns. The photoluminescence (PL) peak intensities of the self-organized GaN nanocolumns were 2.0-2.6 times higher than those of a GaN substrate grown by hydride vapor phase epitaxy. Moreover, no yellow luminescence or ZB-phase GaN emission was observed from the nanocolumns. An InGaN/GaN MQW and p-type GaN were integrated into GaN nanocolumns grown on MLG, displaying a single-peak PL emission at a wavelength of 533 nm. Thus, high-density nitride p-i-n nanocolumns were fabricated on SiO2/Si using the transferred MLG interlayer, indicating the possibility of developing visible nanocolumn LEDs on graphene/SiO2.

  14. Influência do agrotêxtil sobre a densidade populacional de Monosporascus cannonballus em solo cultivado com melancia (Citrullus lanatus Influence of the row cover on the population density of Monosporascus cannonballus in soil cultivated with watermelon (Citrullus lanatus

    Directory of Open Access Journals (Sweden)

    Erika Valente de Medeiros

    2008-06-01

    Full Text Available O fungo Monosporascus cannonballus é um importante patógeno radicular que ocasiona a síndrome denominada colapso em cucurbitáceas. No presente trabalho, objetivou-se, avaliar os efeitos da cobertura de planta com agrotêxtil branco de 15 g m-2, sobre a densidade populacional de M. cannonballus, em solo cultivado com melancia [Citrullus lanatus (Thumb. Matsu & Nakai]. O delineamento experimental utilizado foi o de blocos casualizados em esquema de parcelas subdivididas, com três repetições. As parcelas foram constituídas por utilização ou não do agrotêxtil e as subparcelas pelas épocas de coleta de solo (0, 12, 24, 36, 48 dias após o transplantio. As variáveis analisadas foram densidade de ascósporos, temperatura do solo e do ar. Não houve influência da utilização da cobertura de agrotêxtil perante a densidade de ascósporos de M. cannonballus, no solo cultivado com melancia, mesmo que tenha proporcionado redução nas temperaturas médias do ar e do solo, sendo uma alternativa eficaz de manejo, na produção da melancia Mickylee.The fungus M. cannonballus is an important root pathogen that causes collapse in cucurbitaceas. The present work had as objective to evaluate the effect of the row cover with white polypropylene of 15 g m-2 on the population density of M.cannonballus in soil cultivated with watermelon [Citrullus lanatus (Thumb. Matsu & Nakai]. The experimental design was of randomized blocks using parcels subdivided scheme with three replications. The parcels consisted of use or not row cover and subparcelas through the time of soil collected (0, 12, 24, 36, 48 days after the transplanting. The variables evaluates were ascospores density, soil temperature and air temperature. There was not influence of the characteristics gotten for the row cover before the ascospores density of M. cannonballus, in the soils cultivated with watermelon and proportioning reduction of soil temperature means and air temperature means

  15. Ground Vehicle Robotics

    Science.gov (United States)

    2013-08-20

    Ground Vehicle Robotics Jim Parker Associate Director, Ground Vehicle Robotics UNCLASSIFIED: Distribution Statement A. Approved for public...DATE 20 AUG 2013 2. REPORT TYPE Briefing Charts 3. DATES COVERED 09-05-2013 to 15-08-2013 4. TITLE AND SUBTITLE Ground Vehicle Robotics 5a...Willing to take Risk on technology -User Evaluated -Contested Environments -Operational Data Applied Robotics for Installation & Base Ops -Low Risk

  16. Simulation of Variable-Density Ground-Water Flow and Saltwater Intrusion beneath Manhasset Neck, Nassau County, New York, 1905-2005

    Science.gov (United States)

    Monti, Jack; Misut, Paul E.; Busciolano, Ronald

    2009-01-01

    The coastal-aquifer system of Manhasset Neck, Nassau County, New York, has been stressed by pumping, which has led to saltwater intrusion and the abandonment of one public-supply well in 1944. Measurements of chloride concentrations and water levels in 2004 from the deep, confined aquifers indicate active saltwater intrusion in response to public-supply pumping. A numerical model capable of simulating three-dimensional variable-density ground-water flow and solute transport in heterogeneous, anisotropic aquifers was developed using the U.S. Geological Survey finite-element, variable-density, solute-transport simulator SUTRA, to investigate the extent of saltwater intrusion beneath Manhasset Neck. The model is composed of eight layers representing the hydrogeologic system beneath Manhasset Neck. Four modifications to the area?s previously described hydrogeologic framework were made in the model (1) the bedrock-surface altitude at well N12191 was corrected from a previously reported value, (2) part of the extent of the Raritan confining unit was shifted, (3) part of the extent of the North Shore confining unit was shifted, and (4) a clay layer in the upper glacial aquifer was added in the central and southern parts of the Manhasset Neck peninsula. Ground-water flow and the location of the freshwater-saltwater interface were simulated for three conditions (time periods) (1) a steady-state (predevelopment) simulation of no pumping prior to about 1905, (2) a 40-year transient simulation based on 1939 pumpage representing the 1905-1944 period of gradual saltwater intrusion, and (3) a 60-year transient simulation based on 1995 pumpage representing the 1945-2005 period of stabilized withdrawals. The 1939 pumpage rate (12.1 million gallons per day (Mgal/d)) applied to the 1905-1944 transient simulation caused modeled average water-level declines of 2 and 4 feet (ft) in the shallow and deep aquifer systems from predevelopment conditions, respectively, a net decrease of 5

  17. Sganzerla Cover

    Directory of Open Access Journals (Sweden)

    Victor da Rosa

    2014-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-7917.2014v19n1p158 Neste artigo, realizo uma leitura do cinema de Rogério Sganzerla, desde o clássico O bandido da luz vermelha até os documentários filmados na década de oitenta, a partir de duas noções centrais: cover e over. Para isso, parto de uma controvérsia com o ensaio de Ismail Xavier, Alegorias do subdesenvolvimento, em que o crítico realiza uma leitura do cinema brasileiro da década de sessenta através do conceito de alegoria; depois releio uma série de textos críticos do próprio Sganzerla, publicados em Edifício Sganzerla, procurando repensar as ideias de “herói vazio” ou “cinema impuro” e sugerindo assim uma nova relação do seu cinema com o tempo e a representação; então busco articular tais ideias com certos procedimentos de vanguarda, como a falsificação, a cópia, o clichê e a colagem; e finalmente procuro mostrar que, no cinema de Sganzerla, a partir principalmente de suas reflexões sobre Orson Welles, a voz é usada de maneira a deformar a interpretação naturalista.

  18. Cover Picture.

    Science.gov (United States)

    Breuning; Ruben; Lehn; Renz; Garcia; Ksenofontov; Gütlich; Wegelius; Rissanen

    2000-07-17

    The cover picture shows how both, fine arts and science, avail themselves of a system of intertwined symbolic and iconic languages. They make use of a common set of abstracted signs to report on their results. Thus, already in 1925, Wassily Kandinsky painted a masterpiece (bottom), which now, 75 years later, might be regarded as a blueprint for a scientific project. In his painting, Kandinsky pictured a grid-shaped sign that resembles in effect an actual molecular switch. Apparently following an enigmatic protocol, the groups of Lehn and Gütlich (see p. 2504 ff. for more details) constructed a grid-type inorganic architecture that operates as a three-level magnetic switch (center) triggered by three external perturbations (p, T, hnu). The switching principle is based on the spin-crossover phenomenon of Fe(II) ions and can be monitored by Mössbauer spectroscopy (left) and magnetic measurements (rear). Maybe not by chance, the English translation of the title of the painting "signs" is a homonym of "science", since both presented works are a product of the insatiable curiosity of man and his untiring desire to recognize his existence.

  19. MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model--Documentation of the SEAWAT-2000 Version with the Variable-Density Flow Process (VDF) and the Integrated MT3DMS Transport Process (IMT)

    Science.gov (United States)

    Langevin, Christian D.; Shoemaker, W. Barclay; Guo, Weixing

    2003-01-01

    SEAWAT-2000 is the latest release of the SEAWAT computer program for simulation of three-dimensional, variable-density, transient ground-water flow in porous media. SEAWAT-2000 was designed by combining a modified version of MODFLOW-2000 and MT3DMS into a single computer program. The code was developed using the MODFLOW-2000 concept of a process, which is defined as ?part of the code that solves a fundamental equation by a specified numerical method.? SEAWAT-2000 contains all of the processes distributed with MODFLOW-2000 and also includes the Variable-Density Flow Process (as an alternative to the constant-density Ground-Water Flow Process) and the Integrated MT3DMS Transport Process. Processes may be active or inactive, depending on simulation objectives; however, not all processes are compatible. For example, the Sensitivity and Parameter Estimation Processes are not compatible with the Variable-Density Flow and Integrated MT3DMS Transport Processes. The SEAWAT-2000 computer code was tested with the common variable-density benchmark problems and also with problems representing evaporation from a salt lake and rotation of immiscible fluids.

  20. Cobertura do solo e estoque de nutrientes de duas leguminosas perenes, considerando espaçamentos e densidades de plantio Soil cover and nutrient accumulation of two perennial legumes as functions of spacing and planting densities

    Directory of Open Access Journals (Sweden)

    A. Perin

    2004-02-01

    Full Text Available O estabelecimento de leguminosas herbáceas perenes nos sistemas de produção constitui ainda um desafio, principalmente por apresentarem crescimento inicial lento. Para viabilizar sua implantação, este trabalho objetivou determinar as taxas de cobertura do solo, produção de matéria seca, teores e acumulação de N, P e K das leguminosas herbáceas perenes galáxia (Galactia striata e cudzu tropical (Pueraria phaseoloides, considerando espaçamentos e densidades de plantio. O experimento, instalado em dezembro/98 na Embrapa Agrobiologia, Seropédica (RJ, constou do delineamento em blocos ao acaso, em arranjo fatorial 2 x 2 x 4, com quatro repetições. Os tratamentos constaram das espécies galáxia e cudzu tropical, plantadas em dois espaçamentos entre sulcos de plantio (25 e 50 cm e quatro densidades de plantas (5, 10, 15 e 20 plantas m-1. A densidade adequada para a rápida cobertura do solo para cudzu tropical e galáxia foi de 10 plantas m-1, no espaçamento de 25 cm entre os sulcos de plantio. A maior produção de matéria seca e acumulação de N, P e K na parte aérea das plantas foram evidenciadas apenas no primeiro corte, sendo os maiores valores obtidos no espaçamento de 25 cm e na densidade de 10 plantas m-1. O espaçamento de 25 cm com 10 plantas m-1 foi a combinação mais adequada para a plena formação da cobertura viva do solo com cudzu tropical e galáxia.The establishment of herbaceous perennial leguminous in production systems is still a challenge, mainly because of the slow initial growth. Evaluations of the soil cover ratio, dry matter production, contents and accumulations of nitrogen, phosphorus, and potassium of the herbaceous perennial Galactia striata and Pueraria phaseoloides, sown in different densities and row spacing, aimed at making their establishments feasible. The experiment was conducted in December/98 at Embrapa Agrobiologia, Seropédica (RJ, in a completely randomized block design, as a factorial

  1. Performance and Carbon Emission Analysis on Glass-covering Greenhouse Heating with Ground Source Heat Pump Technology%玻璃温室地源热泵供暖性能与碳排放分析

    Institute of Scientific and Technical Information of China (English)

    柴立龙; 马承伟

    2012-01-01

    The heating test was conducted in a glass-covering multi-span greenhouse ( 756 m ) with groundwater-style GSHP technology. The heat quantity estimating models based on air enthalpy difference method ( AEDM) were developed according to the heating characteristics of GSHP. The economical performance and carbon footprint ( greenhouse gas emission level) of the GSHP was analyzed and compared with currently widely used coal fired heating system ( CFHs) and natural gas fired heating system (GFHs) based on investigated various energy sources price during heating tests. According to the compared results, the GSHPs heating cost is higher than CFHs, but lower than GFHs. Meanwhile, GSHPs CO2 emission during heating is higher than GFHs, but lower than CFHs.In view of the strong coupling between temperature and relative humidity in the greenhouse simulation system, an adaptive decoupling method based on dynamic matrix control was proposed. Taking the measure of feedforward compensation to eliminate interaction between channels of temperature and humidity, an adaptive decoupling algorithm by weighting was designed. The proposed method can adjust the decoupling parameters online under different operating modes, effectively overcome the effect of model severe mismatch to control accuracy. Compared with the traditional PID control, simulation and experimental results both indicated the proposed strategy greatly improved the control performance.%在北京地区一栋玻璃连栋温室(756 m2)中采用地下水式地源热泵(ground source heat pump,简称GSHP)技术进行了冬季供暖试验,并结合GSHP技术的供热特点构建了基于供热末端空气焓差法的供热量计算模型以及供热系统性能分析方法.根据供暖期北京地区能源价格水平,对比当前广泛使用的燃煤供暖系统和天然气供暖系统,系统地评价了GSHP技术的碳排放(温室气体排放水平)和供暖经济性.GSHP供暖成本低于同期燃气供暖,但

  2. BOREAS AFM-12 1-km AVHRR Seasonal Land Cover Classification

    Science.gov (United States)

    Steyaert, Lou; Hall, Forrest G.; Newcomer, Jeffrey A. (Editor); Knapp, David E. (Editor); Loveland, Thomas R.; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology (AFM)-12 team's efforts focused on regional scale Surface Vegetation and Atmosphere (SVAT) modeling to improve parameterization of the heterogeneous BOREAS landscape for use in larger scale Global Circulation Models (GCMs). This regional land cover data set was developed as part of a multitemporal one-kilometer Advanced Very High Resolution Radiometer (AVHRR) land cover analysis approach that was used as the basis for regional land cover mapping, fire disturbance-regeneration, and multiresolution land cover scaling studies in the boreal forest ecosystem of central Canada. This land cover classification was derived by using regional field observations from ground and low-level aircraft transits to analyze spectral-temporal clusters that were derived from an unsupervised cluster analysis of monthly Normalized Difference Vegetation Index (NDVI) image composites (April-September 1992). This regional data set was developed for use by BOREAS investigators, especially those involved in simulation modeling, remote sensing algorithm development, and aircraft flux studies. Based on regional field data verification, this multitemporal one-kilometer AVHRR land cover mapping approach was effective in characterizing the biome-level land cover structure, embedded spatially heterogeneous landscape patterns, and other types of key land cover information of interest to BOREAS modelers.The land cover mosaics in this classification include: (1) wet conifer mosaic (low, medium, and high tree stand density), (2) mixed coniferous-deciduous forest (80% coniferous, codominant, and 80% deciduous), (3) recent visible bum, vegetation regeneration, or rock outcrops-bare ground-sparsely vegetated slow regeneration bum (four classes), (4) open water and grassland marshes, and (5) general agricultural land use/ grasslands (three classes). This land cover mapping approach did not detect small subpixel-scale landscape

  3. Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in shallow, recently recharged ground water -- Input data set for population density (gwava-s_popd)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents 1990 block group population density, in people per square kilometer, in the conterminous United States. The data set was used as an input...

  4. Effects of ground and joint reaction force exercise on lumbar spine and femoral neck bone mineral density in postmenopausal women: a meta-analysis of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Kelley George A

    2012-09-01

    Full Text Available Abstract Background Low bone mineral density (BMD and subsequent fractures are a major public health problem in postmenopausal women. The purpose of this study was to use the aggregate data meta-analytic approach to examine the effects of ground (for example, walking and/or joint reaction (for example, strength training exercise on femoral neck (FN and lumbar spine (LS BMD in postmenopausal women. Methods The a priori inclusion criteria were: (1 randomized controlled trials, (2 exercise intervention ≥ 24 weeks, (3 comparative control group, (4 postmenopausal women, (5 participants not regularly active, i.e., less than 150 minutes of moderate intensity (3.0 to 5.9 metabolic equivalents weight bearing endurance activity per week, less than 75 minutes of vigorous intensity (> 6.0 metabolic equivalents weight bearing endurance activity per week, resistance training g was calculated for each FN and LS BMD result and pooled using random-effects models. Z-score alpha values, 95%confidence intervals (CI and number-needed-to-treat (NNT were calculated for pooled results. Heterogeneity was examined using Q and I2. Mixed-effects ANOVA and simple meta-regression were used to examine changes in FN and LS BMD according to selected categorical and continuous variables. Statistical significance was set at an alpha value ≤0.05 and a trend at >0.05 to ≤ 0.10. Results Small, statistically significant exercise minus control group improvements were found for both FN (28 g’s, 1632 participants, g = 0.288, 95% CI = 0.102, 0.474, p = 0.002, Q = 90.5, p I2 = 70.1%, NNT = 6 and LS (28 g’s, 1504 participants, g = 0.179, 95% CI = −0.003, 0.361, p = 0.05, Q = 77.7, p I2 = 65.3%, NNT = 6 BMD. Clinically, it was estimated that the overall changes in FN and LS would reduce the 20-year relative risk of osteoporotic fracture at any site by approximately 11% and 10%, respectively. None of the mixed

  5. Ground penetrating radar and terrestrial laser scanner surveys on deposits of dilute pyroclastic density current deposits: insights for dune bedform genesis

    Science.gov (United States)

    Rémi Dujardin, Jean; Amin Douillet, Guilhem; Abolghasem, Amir; Cordonnier, Benoit; Kueppers, Ulrich; Bano, Maksim; Dingwell, Donald B.

    2014-05-01

    Dune bedforms formed by dilute pyroclastic density currents (PDC) are often described or interpreted as antidunes and chute and pools. However, the interpretation remains essentially speculative and is not well understood. This is largely due to the seeming impossibility of in-situ measurements and experimental scaling, as well as the lack of recent, 3D exposures. Indeed, most dune bedform cross-stratifications from the dilute PDC record outcrop in 2D sections. The 2006 eruption of Tungurahua has produced well-developed bedforms that are well-exposed on the surface of the deposits with easy access. We performed a survey of these deposits combining ground penetrating radar (GPR) profiling with terrestrial laser scanning of the surface. The GPR survey was carried in dense arrays (from 10 to 25 cm spacing between profiles) over ca. 10 m long bedforms. GPR profiles were corrected for topography from photogrammetry data. An in-house software, RadLab (written in matlab), was used for common processing of individual profiles and 2D & 3D topographic migration. Each topography-corrected profile was then loaded into a seismic interpretation software, OpenDtect, for 3D visualization and interpretation. Most bedforms show high lateral stability that is independent of the cross-stratification pattern (that varies between stoss-aggrading bedsets, stoss-erosive bedsets and stoss-depositional lensoidal layers). Anecdotic bedforms have their profiles that evolve laterally (i.e. in a direction perpendicular to the flow direction). Cannibalization of two dune bedforms into a single one on one end of the profile can evolve into growth of a single bedform at the other lateral end. Also, lateral variation in the migration direction occurs, i.e. a single bedform can show upstream aggradation at one lateral end of the bedform, but show downstream migration at the other end. Some bedforms have great variations in their internal structure. Several episodes of growth and erosion can be

  6. Modeling increasing effect of soil temperature through plastic film mulch in ground cover rice production system using CERES-Rice%基于CERES-Rice模型的覆膜旱作稻田增温效应模拟

    Institute of Scientific and Technical Information of China (English)

    马雯雯; 金欣欣; 石建初; 宁松瑞; 李森; 陶玥玥; 张亚男; 左强

    2015-01-01

    水稻覆膜旱作技术具有显著的节水、增温、防污和减排效应,是节水稻作技术体系的重要措施之一,将CERES-Rice模型用于覆膜旱作条件时,必须首先解决覆膜增温效应的准确模拟问题。该文拟应用热量传输理论及目前旱地作物生产系统中采用的覆膜增温效应模拟方法,来模拟水稻覆膜旱作生产体系中的增温效应,从而为完善 CERES-Rice 模型并使其能用于覆膜旱作水稻的生长模拟奠定基础。参数调校与模型检验验证通过2013、2014年在湖北房县开展的2 a水稻覆膜旱作田间试验来进行,共涉及淹水(对照)、覆膜湿润栽培和覆膜旱作共3个水分处理,分别对2个生长季、2个覆膜处理地表5 cm及地下10、20 cm处温度的变化过程进行了模拟,结果表明:经过参数调校后,所建立的覆膜增温模型可较好地模拟覆膜稻田地表和剖面上土壤温度的变化规律,地表5 cm处土壤温度模拟值与实测值的均方根差、相对均方根差分别低于1.8℃和10%,相关系数在0.89以上(P<0.01);尽管地下10、20 cm处的模拟误差稍大,也基本可满足要求,相应的均方根误差<3.2℃,相对均方根差<15%,相关系数>0.65(P<0.01)。%As one of the most promising water-saving rice production technologies, the ground cover rice production system (GCRPS) has been found to save water application, increase soil temperature, and reduce nitrogen pollution and methane emission. However, the feasibility of CERES-Rice, a software package widely and successfully applied in the traditional paddy rice production system (TPRPS), for simulating the rice growth in the GCRPS still remains unknown and needs further research. Undoubtedly, it should be based on accurately quantifying the effect of soil temperature enhancement caused by the ground cover material (chosen as the plastic film in this study). Therefore, the objective of

  7. Full charge-density scheme with a kinetic-energy correction: Application to ground-state properties of the 4d metals

    DEFF Research Database (Denmark)

    Vitos, Levente; Kollár, J.; Skriver, Hans Lomholt

    1997-01-01

    We present a full charge-density technique to evaluate total energies from the output of self-consistent linear muffin-tin orbitals (LMTO) calculations in the atomic-sphere approximation (ASA). The Coulomb energy is calculated exactly from the complete, nonspherically symmetric charge density def...

  8. Limited Impact of a Fall-Seeded, Spring-Terminated Rye Cover Crop on Beneficial Arthropods.

    Science.gov (United States)

    Dunbar, Mike W; Gassmann, Aaron J; O'Neal, Matthew E

    2017-04-01

    Cover crops are beneficial to agroecosystems because they decrease soil erosion and nutrient loss while increasing within-field plant diversity. Greater plant diversity within cropping systems can positively affect beneficial arthropod communities. We hypothesized that increasing plant diversity within annually rotated corn and soybean with the addition of a rye cover crop would positively affect the beneficial ground and canopy-dwelling communities compared with rotated corn and soybean grown without a cover crop. From 2011 through 2013, arthropod communities were measured at two locations in Iowa four times throughout each growing season. Pitfall traps were used to sample ground-dwelling arthropods within the corn and soybean plots and sweep nets were used to measure the beneficial arthropods in soybean canopies. Beneficial arthropods captured were identified to either class, order, or family. In both corn and soybean, community composition and total community activity density and abundance did not differ between plots that included the rye cover crop and plots without the rye cover crop. Most taxa did not significantly respond to the presence of the rye cover crop when analyzed individually, with the exceptions of Carabidae and Gryllidae sampled from soybean pitfall traps. Activity density of Carabidae was significantly greater in soybean plots that included a rye cover crop, while activity density of Gryllidae was significantly reduced in plots with the rye cover crop. Although a rye cover crop may be agronomically beneficial, there may be only limited effects on beneficial arthropods when added within an annual rotation of corn and soybean. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Microtines and ground squirrels of the coastal plain of the Arctic National Wildlife Refuge: Notes on distributions, densities, and general ecology

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Densities of Microtus oeconomus decreased at the more inland study areas between years. Dicrostonyx torguatus and Lemmus sibericus species were more common towards...

  10. Comparative analysis of distribution and abundance of West Nile and Eastern Equine Encephalomyelitis virus vectors in Suffolk County, New York, using human population density and land use/cover data

    Science.gov (United States)

    Rochlin, I.; Harding, K.; Ginsberg, H.S.; Campbell, S.R.

    2008-01-01

    Five years of CDC light trap data from Suffolk County, NY, were analyzed to compare the applicability of human population density (HPD) and land use/cover (LUC) classification systems to describe mosquito abundance and to determine whether certain mosquito species of medical importance tend to be more common in urban (defined by HPD) or residential (defined by LUC) areas. Eleven study sites were categorized as urban or rural using U.S. Census Bureau data and by LUC types using geographic information systems (GISs). Abundance and percent composition of nine mosquito taxa, all known or potential vectors of arboviruses, were analyzed to determine spatial patterns. By HPD definitions, three mosquito species, Aedes canadensis (Theobald), Coquillettidia perturbans (Walker), and Culiseta melanura (Coquillett), differed significantly between habitat types, with higher abundance and percent composition in rural areas. Abundance and percent composition of these three species also increased with freshwater wetland, natural vegetation areas, or a combination when using LUC definitions. Additionally, two species, Ae. canadensis and Cs. melanura, were negatively affected by increased residential area. One species, Aedes vexans (Meigen), had higher percent composition in urban areas. Two medically important taxa, Culex spp. and Aedes triseriatus (Say), were proportionally more prevalent in residential areas by LUC classification, as was Aedes trivittatus (Coquillett). Although HPD classification was readily available and had some predictive value, LUC classification resulted in higher spatial resolution and better ability to develop location specific predictive models.

  11. Future Road Density

    Data.gov (United States)

    U.S. Environmental Protection Agency — Road density is generally highly correlated with amount of developed land cover. High road densities usually indicate high levels of ecological disturbance. More...

  12. Forests and Forest Cover, Forest areas as captured by orthophotography. Contains some attribution of forest type depending on imagery and ground-truthing if available., Published in 2007, 1:2400 (1in=200ft) scale, Howard County Government.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Forests and Forest Cover dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Orthoimagery information as of 2007. It is described...

  13. Land Use and Land Cover, Existing land use derived from orthoimagery. Ground-truthing from discussion with local plan commission members., Published in 2000, 1:12000 (1in=1000ft) scale, Portage County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Land Use and Land Cover dataset, published at 1:12000 (1in=1000ft) scale, was produced all or in part from Orthoimagery information as of 2000. It is described...

  14. ACCURACY ASSESSMENT OF LIDAR-DERIVED DIGITAL TERRAIN MODEL (DTM WITH DIFFERENT SLOPE AND CANOPY COVER IN TROPICAL FOREST REGION

    Directory of Open Access Journals (Sweden)

    M. R. M. Salleh

    2015-10-01

    Full Text Available Airborne Light Detection and Ranging (LiDAR technology has been widely used recent years especially in generating high accuracy of Digital Terrain Model (DTM. High density and good quality of airborne LiDAR data promises a high quality of DTM. This study focussing on the analysing the error associated with the density of vegetation cover (canopy cover and terrain slope in a LiDAR derived-DTM value in a tropical forest environment in Bentong, State of Pahang, Malaysia. Airborne LiDAR data were collected can be consider as low density captured by Reigl system mounted on an aircraft. The ground filtering procedure use adaptive triangulation irregular network (ATIN algorithm technique in producing ground points. Next, the ground control points (GCPs used in generating the reference DTM and these DTM was used for slope classification and the point clouds belong to non-ground are then used in determining the relative percentage of canopy cover. The results show that terrain slope has high correlation for both study area (0.993 and 0.870 with the RMSE of the LiDAR-derived DTM. This is similar to canopy cover where high value of correlation (0.989 and 0.924 obtained. This indicates that the accuracy of airborne LiDAR-derived DTM is significantly affected by terrain slope and canopy caver of study area.

  15. Ground Vehicle Robotics Presentation

    Science.gov (United States)

    2012-08-14

    Mr. Jim Parker Associate Director Ground Vehicle Robotics Distribution Statement A. Approved for public release Report Documentation Page...Briefing 3. DATES COVERED 01-07-2012 to 01-08-2012 4. TITLE AND SUBTITLE Ground Vehicle Robotics Presentation 5a. CONTRACT NUMBER 5b. GRANT...ABSTRACT Provide Transition-Ready, Cost-Effective, and Innovative Robotics and Control System Solutions for Manned, Optionally-Manned, and Unmanned

  16. Quasi-Low-Dimensional Electron Gas with One Populated Band as a Testing Ground for Time-Dependent Density-Functional Theory of Mesoscopic Systems.

    Science.gov (United States)

    Nazarov, Vladimir U

    2017-06-09

    We find an exact analytical solution to the exchange-only time-dependent density-functional theory (TDDFT) problem for a significant class of quasi-low-dimensional (QLD) materials: QLD electron gas with only one band filled in the direction perpendicular to the layer or wire. The theory yields the TD exchange potential as an explicit nonlocal operator of the TD spin density. The dressed interband (image states) excitation spectra of quasi-two-dimensional electron gas are obtained, while the comparison with the Kohn-Sham transitions provides insights into the qualitative and quantitative role of the many-body interactions. Important cancellations between the Hartree f_{H} and the exchange f_{x} kernels of TDDFT are found in the low-density regime, elucidating the interrelations between the Kohn-Sham and the many-body dynamics in mesoscopic systems.

  17. Quasi-Low-Dimensional Electron Gas with One Populated Band as a Testing Ground for Time-Dependent Density-Functional Theory of Mesoscopic Systems

    Science.gov (United States)

    Nazarov, Vladimir U.

    2017-06-01

    We find an exact analytical solution to the exchange-only time-dependent density-functional theory (TDDFT) problem for a significant class of quasi-low-dimensional (QLD) materials: QLD electron gas with only one band filled in the direction perpendicular to the layer or wire. The theory yields the TD exchange potential as an explicit nonlocal operator of the TD spin density. The dressed interband (image states) excitation spectra of quasi-two-dimensional electron gas are obtained, while the comparison with the Kohn-Sham transitions provides insights into the qualitative and quantitative role of the many-body interactions. Important cancellations between the Hartree fH and the exchange fx kernels of TDDFT are found in the low-density regime, elucidating the interrelations between the Kohn-Sham and the many-body dynamics in mesoscopic systems.

  18. 地被植物在郑州都市区园林绿化中的组成结构及管理对策研究%The investigation and analysis about common ground cover plants of metropolitan area parks in Zhengzhou City

    Institute of Scientific and Technical Information of China (English)

    汪进; 杨旭; 高闪闪; 何瑞珍

    2014-01-01

    The ground cover plants in the major urban parks and plazas of Zhengzhou City were investigated by using on‐the‐spot statistical investigation in this paper ,and the vegeta‐tion characteristics , selection criteria , and maintenance management , etc . w ere discussed and analysed .The results showed that the species of ground cover plants are simplex ,with smaller size plantation and often separatly planted with many bare grounds and extensive management at late stage . T herefore , some effective measurs are proposed by reasonable planting according to the viewing characteristis of different species in different growth seasonsand enhancing their management in time ,which can greatly improve their ornamental value ,and hence increase the level of ground cover plants landscaping .%采用实地调查统计的方法对郑州市各大公园及路边广场的地被植物及其特点、选择标准、养护管理等进行了研究分析。结果表明:当前地被植物品种单一,种植面积较小,且多单独种植,混合应用较少,较多地段没有地被植物覆盖,后期管理粗放。建议充分利用每种地被植物不同时期的观赏特点,种植时合理搭配,及时管理,以大大提高观赏价值,从而提高地被植物的造景水平。

  19. Land Cover - Minnesota Land Cover Classification System

    Data.gov (United States)

    Minnesota Department of Natural Resources — Land cover data set based on the Minnesota Land Cover Classification System (MLCCS) coding scheme. This data was produced using a combination of aerial photograph...

  20. The Land Surface Temperature Impact to Land Cover Types

    Science.gov (United States)

    Ibrahim, I.; Abu Samah, A.; Fauzi, R.; Noor, N. M.

    2016-06-01

    Land cover type is an important signature that is usually used to understand the interaction between the ground surfaces with the local temperature. Various land cover types such as high density built up areas, vegetation, bare land and water bodies are areas where heat signature are measured using remote sensing image. The aim of this study is to analyse the impact of land surface temperature on land cover types. The objectives are 1) to analyse the mean temperature for each land cover types and 2) to analyse the relationship of temperature variation within land cover types: built up area, green area, forest, water bodies and bare land. The method used in this research was supervised classification for land cover map and mono window algorithm for land surface temperature (LST) extraction. The statistical analysis of post hoc Tukey test was used on an image captured on five available images. A pixel-based change detection was applied to the temperature and land cover images. The result of post hoc Tukey test for the images showed that these land cover types: built up-green, built up-forest, built up-water bodies have caused significant difference in the temperature variation. However, built up-bare land did not show significant impact at p<0.05. These findings show that green areas appears to have a lower temperature difference, which is between 2° to 3° Celsius compared to urban areas. The findings also show that the average temperature and the built up percentage has a moderate correlation with R2 = 0.53. The environmental implications of these interactions can provide some insights for future land use planning in the region.

  1. A study of electron density profiles in relation to ionization sources and ground-based radio wave absorption measurements, part 2

    Science.gov (United States)

    Gnanalingam, S.; Kane, J. A.

    1975-01-01

    The D-region ion production functions are used to calculate the relationship between radio wave absorption and the flux level of X-rays in the 1-8A wavelength band. In order to bring this calculation into agreement with the empirically established relationship, it was found necessary to reduce by, a factor of about 5, the Meira nitric oxide densities below 90 km.

  2. The Porcupine herd of barren ground caribou

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the porcupine herd of the barren ground caribou. The report covers the short history, the winter range, migration route, phenology, movements and...

  3. feasibility of winter cover crop production under rainfed conditions in ...

    African Journals Online (AJOL)

    ACSS

    Low winter rainfall poses a challenge to production of high biomass from cover ... February planted cover crops had the lowest residues remaining at maize ..... Interaction effects of planting date and cover crop species on cover crop dry weight at termination in Eastern Cape ... to weed species density (per m2) at cover crop.

  4. Seeing the Snow through the Trees: Towards a Validated Canopy Adjustment for Fractional Snow Covered Area

    Science.gov (United States)

    Coons, L.; Nolin, A. W.; Painter, T.

    2012-12-01

    Satellite remote sensing is an important tool for monitoring the spatial distribution of snow cover, which acts as a vital reservoir of water for human and ecosystem needs. Current methods exist mapping the fraction of snow in each image pixel from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat Thematic Mapper (TM). Although these methods can effectively detect this fractional snow-covered area (fSCA) in open areas, snow cover is underestimated in forested areas where canopy cover obscures the snow. Accounting for obscured snow cover will significantly improve estimates of fSCA for hydrologic forecasting and monitoring. This study will address how individual trees and the overall forest canopy affect snow distributions on the ground with the goal of determining metrics that can parameterize the spatial patterns of sub-canopy snow cover. Snow cover measurements were made during winter 2011-2012 at multiple sites representing a range of canopy densities. In the snow-free season, we used terrestrial laser scanning (TLS) and manual field methods to fully characterize the forest canopy height, canopy gap fraction, crown width, tree diameter at breast height (DBH), and stand density. We also use multi-angle satellite imagery from MISR and airborne photos to map canopy characteristics over larger areas. Certain canopy structure characteristics can be represented with remote sensing data. These data serve as a key first step in developing canopy adjustment factors for fSCA from MODIS, TM, and other snow mapping sensors.

  5. Subsystem density-functional theory as an effective tool for modeling ground and excited states, their dynamics and many-body interactions

    Science.gov (United States)

    Krishtal, Alisa; Sinha, Debalina; Genova, Alessandro; Pavanello, Michele

    2015-05-01

    Subsystem density-functional theory (DFT) is an emerging technique for calculating the electronic structure of complex molecular and condensed phase systems. In this topical review, we focus on some recent advances in this field related to the computation of condensed phase systems, their excited states, and the evaluation of many-body interactions between the subsystems. As subsystem DFT is in principle an exact theory, any advance in this field can have a dual role. One is the possible applicability of a resulting method in practical calculations. The other is the possibility of shedding light on some quantum-mechanical phenomenon which is more easily treated by subdividing a supersystem into subsystems. An example of the latter is many-body interactions. In the discussion, we present some recent work from our research group as well as some new results, casting them in the current state-of-the-art in this review as comprehensively as possible.

  6. Exact integral constraint requiring only the ground-state electron density as input on the exchange-correlation force - partial differential(V)(xc)(r)/partial differential(r) for spherical atoms.

    Science.gov (United States)

    March, N H; Nagy, A

    2008-11-21

    Following some studies of integral(n)(r)inverted DeltaV(r)dr by earlier workers for the density functional theory (DFT) one-body potential V(r) generating the exact ground-state density, we consider here the special case of spherical atoms. The starting point is the differential virial theorem, which is used, as well as the Hiller-Sucher-Feinberg [Phys. Rev. A 18, 2399 (1978)] identity to show that the scalar quantity paralleling the above vector integral, namely, integral(n)(r) partial differential(V)(r)/partial differential(r)dr, is determined solely by the electron density n(0) at the nucleus for the s-like atoms He and Be. The force - partial differential(V)/ partial differential(r) is then related to the derivative of the exchange-correlation potential V(xc)(r) by terms involving only the external potential in addition to n(r). The resulting integral constraint should allow some test of the quality of currently used forms of V(xc)(r). The article concludes with results from the differential virial theorem and the Hiller-Sucher-Feinberg identity for the exact many-electron theory of spherical atoms, as well as for the DFT for atoms such as Ne with a closed p shell.

  7. Localizing Ground-Penetrating Radar

    Science.gov (United States)

    2014-11-01

    ing Ground-Penetrating Radar (LGPR) uses very high frequency (VHF) radar reflections of underground features to generate base- line maps and then...Innovative ground- penetrating radar that maps underground geological features provides autonomous vehicles with real-time localization. Localizing...NOV 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Localizing Ground-Penetrating Radar 5a. CONTRACT NUMBER

  8. Ground-based Pa$\\alpha$ Narrow-band Imaging of Local Luminous Infrared Galaxies I: Star Formation Rates and Surface Densities

    CERN Document Server

    Tateuchi, Ken; Motohara, Kentaro; Takahashi, Hidenori; Kato, Natsuko Mitani; Kitagawa, Yutaro; Todo, Soya; Toshikawa, Koji; Sako, Shigeyuki; Uchimoto, Yuka K; Ohsawa, Ryou; Asano, Kentaro; Ita, Yoshifusa; Kamizuka, Takafumi; Komugi, Shinya; Koshida, Shintaro; Manabe, Sho; Nakamura, Tomohiko; Nakashima, Asami; Okada, Kazushi; Takagi, Toshinobu; Tanabé, Toshihiko; Uchiyama, Mizuho; Aoki, Tsutomu; Doi, Mamoru; Handa, Toshihiro; Kawara, Kimiaki; Kohno, Kotaro; Minezaki, Takeo; Miyata, Takashi; Morokuma, Tomoki; Soyano, Takeo; Tamura, Yoichi; Tanaka, Masuo; Tarusawa, Ken'ichi; Yoshii, Yuzuru

    2014-01-01

    Luminous infrared galaxies (LIRGs) are enshrouded by a large amount of dust, produced by their active star formation, and it is difficult to measure their activity in the optical wavelength. We have carried out Pa$\\alpha$ narrow-band imaging observations of 38 nearby star-forming galaxies including 33 LIRGs listed in $IRAS$ RBGS catalog with the Atacama Near InfraRed camera (ANIR) on the University of Tokyo Atacama Observatory (TAO) 1.0 m telescope (miniTAO). Star formation rates (SFRs) estimated from the Pa$\\alpha$ fluxes, corrected for dust extinction using the Balmer Decrement Method (typically $A_V$ $\\sim$ 4.3 mag), show a good correlation with those from the bolometric infrared luminosity of $IRAS$ data within a scatter of 0.27 dex. This suggests that the correction of dust extinction for Pa$\\alpha$ flux is sufficient in our sample. We measure the physical sizes and the surface density of infrared luminosities ($\\Sigma_{L(\\mathrm{IR})}$) and $SFR$ ($\\Sigma_{SFR}$) of star-forming region for individual ga...

  9. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  10. Enhanced computational efficiency in the direct determination of the two-electron reduced density matrix from the anti-Hermitian contracted Schrödinger equation with application to ground and excited states of conjugated π-systems

    Energy Technology Data Exchange (ETDEWEB)

    Sand, Andrew M.; Mazziotti, David A., E-mail: damazz@uchicago.edu [Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)

    2015-10-07

    Determination of the two-electron reduced density matrix (2-RDM) from the solution of the anti-Hermitian contracted Schrödinger equation (ACSE) yields accurate energies and properties for both ground and excited states. Here, we develop a more efficient method to solving the ACSE that uses second-order information to select a more optimal step towards the solution. Calculations on the ground and excited states of water, hydrogen fluoride, and conjugated π systems show that the improved ACSE algorithm is 10-20 times faster than the previous ACSE algorithm. The ACSE can treat both single- and multi-reference electron correlation with the initial 2-RDM from a complete-active-space self-consistent-field (CASSCF) calculation. Using the improved algorithm, we explore the relationship between truncation of the active space in the CASSCF calculation and the accuracy of the energy and 2-RDM from the ACSE calculation. The accuracy of the ACSE, we find, is less sensitive to the size of the active space than the accuracy of other wavefunction methods, which is useful when large active space calculations are computationally infeasible.

  11. Enhanced computational efficiency in the direct determination of the two-electron reduced density matrix from the anti-Hermitian contracted Schrödinger equation with application to ground and excited states of conjugated π-systems.

    Science.gov (United States)

    Sand, Andrew M; Mazziotti, David A

    2015-10-01

    Determination of the two-electron reduced density matrix (2-RDM) from the solution of the anti-Hermitian contracted Schrödinger equation (ACSE) yields accurate energies and properties for both ground and excited states. Here, we develop a more efficient method to solving the ACSE that uses second-order information to select a more optimal step towards the solution. Calculations on the ground and excited states of water, hydrogen fluoride, and conjugated π systems show that the improved ACSE algorithm is 10-20 times faster than the previous ACSE algorithm. The ACSE can treat both single- and multi-reference electron correlation with the initial 2-RDM from a complete-active-space self-consistent-field (CASSCF) calculation. Using the improved algorithm, we explore the relationship between truncation of the active space in the CASSCF calculation and the accuracy of the energy and 2-RDM from the ACSE calculation. The accuracy of the ACSE, we find, is less sensitive to the size of the active space than the accuracy of other wavefunction methods, which is useful when large active space calculations are computationally infeasible.

  12. GROUND-BASED Paα NARROW-BAND IMAGING OF LOCAL LUMINOUS INFRARED GALAXIES. I. STAR FORMATION RATES AND SURFACE DENSITIES

    Energy Technology Data Exchange (ETDEWEB)

    Tateuchi, Ken; Konishi, Masahiro; Motohara, Kentaro; Takahashi, Hidenori; Kato, Natsuko Mitani; Kitagawa, Yutaro; Todo, Soya; Toshikawa, Koji; Sako, Shigeyuki; Uchimoto, Yuka K.; Ohsawa, Ryou; Asano, Kentaro; Kamizuka, Takafumi; Nakamura, Tomohiko; Okada, Kazushi [Institute of Astronomy, Graduate School of Science, The University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Ita, Yoshifusa [Astronomical Institute, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Komugi, Shinya [Division of Liberal Arts, Kogakuin University, 2665-1, Hachioji, Tokyo 192-0015 (Japan); Koshida, Shintaro [Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); Manabe, Sho [Department of Earth and Planetary Sciences, Kobe University, Kobe 657-8501 (Japan); Nakashima, Asami, E-mail: tateuchi@ioa.s.u-tokyo.ac.jp [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); and others

    2015-03-15

    Luminous infrared galaxies (LIRGs) are enshrouded by a large amount of dust produced by their active star formation, and it is difficult to measure their activity in optical wavelengths. We have carried out Paα narrow-band imaging observations of 38 nearby star forming galaxies including 33 LIRGs listed in the IRAS Revised Bright Galaxy Sample catalog with the Atacama Near InfraRed camera on the University of Tokyo Atacama Observatory (TAO) 1.0 m telescope (miniTAO). Star formation rates (SFRs) estimated from the Paα fluxes, corrected for dust extinction using the Balmer decrement method (typically A{sub V} ∼ 4.3 mag), show a good correlation with those from the bolometric infrared luminosity of the IRAS data within a scatter of 0.27 dex. This suggests that the correction of dust extinction for the Paα flux is sufficient in our sample. We measure the physical sizes and surface densities of infrared luminosities (Σ{sub L(IR)}) and the SFR (Σ{sub SFR}) of star forming regions for individual galaxies, and we find that most of the galaxies follow a sequence of local ultra-luminous or luminous infrared galaxies (U/LIRGs) on the L(IR)-Σ{sub L(IR)} and SFR-Σ{sub SFR} plane. We confirm that a transition of the sequence from normal galaxies to U/LIRGs is seen at L(IR) = 8 × 10{sup 10} L {sub ☉}. Also, we find that there is a large scatter in physical size, different from normal galaxies or ULIRGs. Considering the fact that most U/LIRGs are merging or interacting galaxies, this scatter may be caused by strong external factors or differences in their merging stages.

  13. What Medicare Covers

    Science.gov (United States)

    ... What Part A covers Medicare Part A hospital insurance covers inpatient hospital care, skilled nursing facility, hospice, lab tests, surgery, ... Medicare Covers Drug Coverage (Part D) Supplements & Other Insurance Claims & ... doctors, providers, hospitals & plans Where can I get covered medical items? ...

  14. Valence excitation energies of alkenes, carbonyl compounds, and azabenzenes by time-dependent density functional theory: Linear response of the ground state compared to collinear and noncollinear spin-flip TDDFT with the Tamm-Dancoff approximation

    Science.gov (United States)

    Isegawa, Miho; Truhlar, Donald G.

    2013-04-01

    Time-dependent density functional theory (TDDFT) holds great promise for studying photochemistry because of its affordable cost for large systems and for repeated calculations as required for direct dynamics. The chief obstacle is uncertain accuracy. There have been many validation studies, but there are also many formulations, and there have been few studies where several formulations were applied systematically to the same problems. Another issue, when TDDFT is applied with only a single exchange-correlation functional, is that errors in the functional may mask successes or failures of the formulation. Here, to try to sort out some of the issues, we apply eight formulations of adiabatic TDDFT to the first valence excitations of ten molecules with 18 density functionals of diverse types. The formulations examined are linear response from the ground state (LR-TDDFT), linear response from the ground state with the Tamm-Dancoff approximation (TDDFT-TDA), the original collinear spin-flip approximation with the Tamm-Dancoff (TD) approximation (SF1-TDDFT-TDA), the original noncollinear spin-flip approximation with the TDA approximation (SF1-NC-TDDFT-TDA), combined self-consistent-field (SCF) and collinear spin-flip calculations in the original spin-projected form (SF2-TDDFT-TDA) or non-spin-projected (NSF2-TDDFT-TDA), and combined SCF and noncollinear spin-flip calculations (SF2-NC-TDDFT-TDA and NSF2-NC-TDDFT-TDA). Comparing LR-TDDFT to TDDFT-TDA, we observed that the excitation energy is raised by the TDA; this brings the excitation energies underestimated by full linear response closer to experiment, but sometimes it makes the results worse. For ethylene and butadiene, the excitation energies are underestimated by LR-TDDFT, and the error becomes smaller making the TDA. Neither SF1-TDDFT-TDA nor SF2-TDDFT-TDA provides a lower mean unsigned error than LR-TDDFT or TDDFT-TDA. The comparison between collinear and noncollinear kernels shows that the noncollinear kernel

  15. Sky cover from MFRSR observations

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-07-01

    Full Text Available The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their modeled clear-sky counterparts are the main components of a new method for estimating the fractional sky cover of different cloud types, including cumuli. The performance of this method is illustrated using 1-min resolution data from a ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR. The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM Climate Research Facility (ACRF Southern Great Plains (SGP site during the summer of 2007 and represent 13 days with cumuli. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

  16. Grounded cognition.

    Science.gov (United States)

    Barsalou, Lawrence W

    2008-01-01

    Grounded cognition rejects traditional views that cognition is computation on amodal symbols in a modular system, independent of the brain's modal systems for perception, action, and introspection. Instead, grounded cognition proposes that modal simulations, bodily states, and situated action underlie cognition. Accumulating behavioral and neural evidence supporting this view is reviewed from research on perception, memory, knowledge, language, thought, social cognition, and development. Theories of grounded cognition are also reviewed, as are origins of the area and common misperceptions of it. Theoretical, empirical, and methodological issues are raised whose future treatment is likely to affect the growth and impact of grounded cognition.

  17. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    1999-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...

  18. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    2002-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...

  19. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... such as lowpermeability clay soils and geomembranes are required. The avoidance of water input to organic waste may impede the microbial stabilization processes including gas generation. Therefore watertight top covers may be in conflict with the purposes of reactor landfills (see Chapter 10.6). At some sites covers...... sometimes are made to include components for recirculation of landfill leachate (see Section 10.9.2 for more details). The top cover is an important factor in the water management of landfills. Details about water infiltration through top covers and its influence on the hydrology of the landfill is covered...

  20. Monitoring of Land-Cover Dynamic Change in Lancangjiang River Cascaded Hydropower Area

    Institute of Scientific and Technical Information of China (English)

    LIU Hongjiang; XIE Hongzhong; CHEN Lihui; GAN Shu; ZHANG Jun; WEI Fangqiang

    2006-01-01

    The analysis of the 3 stages' (1988,1996,2000) variation of landcover is performed according to Thematic Mapper (TM) and Enhancement Thematic Mapper(ETM) satellite image by combining ground GIS database with GPS field collected data in the area of Xiaowan-Dachaoshan Reservoirs of Lancangjiang River cascaded Hydropower Area. Consequently, the land-cover is divided into five subclasses, namely water, paddy field and wetland, bare dryland and sparse shrub, secondary forest and density forest. The result showed that the areas of bare land, upland and secondary forest decreased in 1988-1996, whereas from 1996 to 2000, water body and density forest keep invariability while the areas of paddy field and wetland, bare dryland and sparse scrub increasing and the area of secondary forest decrease; Features of reciprocal transformation between density forest and other type of land-cover had two points, i.e. secondary forest, bare dryland and sparse shrub converted to density forest; and density forest converted to secondary forest and paddy field and wetland. It reflects the dynamic variation of density forest; the area which slope less than 8° and greater than 15° shows bigger variation, however, less change in 8°-15°.

  1. Where’s the Ground Surface? – Elevation Bias in LIDAR-derived Digital Elevation Models Due to Dense Vegetation in Oregon Tidal Marshes

    Science.gov (United States)

    Light Detection and Ranging (LIDAR) is a powerful resource for coastal and wetland managers and its use is increasing. Vegetation density and other land cover characteristics influence the accuracy of LIDAR-derived ground surface digital elevation models; however the degree to wh...

  2. Grau de cobertura do solo e dinâmica da vegetação em olivais de sequeiro com a introdução de herbicidas Ground cover and dynamic of weeds after the introduction of herbicides as soil management system in a rainfed olive orchard

    Directory of Open Access Journals (Sweden)

    Manuel Ângelo Rodrigues

    2009-12-01

    Full Text Available São apresentados resultados do grau de cobertura do solo e da dinâmica da vegetação num olival de sequeiro, localizado em Mirandela, após a introdução de herbicidas como estratégia de manutenção do solo. As modalidades em estudo foram: mobilização tradicional; herbicida pós-emergência (glifosato; e herbicida com componentes de acção residual e pós-emergência (diurão+glifosato+terbut ilazina. O grau de cobertura e a composição da vegetação foram avaliados desde 2002 a 2007 pelo método do ponto quadrado. Ambas as soluções herbicidas combateram adequadamente a vegetação herbácea em aplicação única anual. O grau de cobertura no talhão mobilizado, antes da primeira mobilização, oscilou entre 50 a 80 % e 30 a 60 % debaixo e fora da copa, respectivamente. O tratamento com glifosato permitiu um grau de cobertura em Abril entre 60 a 90 % debaixo da copa e 40 a 50 % fora da copa. No tratamento com herbicida residual o grau de cobertura do solo foi sempre muito baixo ao longo do ano. A gestão da vegetação com glifosato permitiu a cobertura do solo durante todo o ano, com vegetação viva desde o Outono à Primavera e um mulching de vegetação morta durante o Verão. Nas restantes modalidades o solo permaneceu descoberto durante grande parte do ano. No talhão gerido com glifosato a vegetação manteve elevada dinâmica. Um ano após o início da aplicação de glifosato apareceu a dominar o coberto Ornithopus compressus. Com o tempo ganharam importância algumas espécies de Inverno de ciclo muito cur-to (como Mibora mínima e Logfia gallicae outras de elevada produção de sementes e fácil dispersão pelo vento (como Hypochaeris radicata e Conyza canadensis com origem provável em incultos e caminhos que circundam o olival ou em plantas individuais que escaparam à acção dos herbicidas.Results of the percentage of ground cover by weeds and the dynamic of the vegetation are presented after the introduction of

  3. Adapting sampling plans to caribou distribution on calving grounds

    Directory of Open Access Journals (Sweden)

    Michel Crête

    1991-10-01

    Full Text Available Between 1984 and 1988, the size of the two caribou herds in northern Québec was derived by combining estimates of female numbers on calving grounds in June and composition counts during rut in autumn. Sampling with aerial photos was conducted on calving grounds to determine the number of animals per km2, telemetry served to estimate the proportion of females in the census area at the time of photography in addition to summer survival rate, and helicopter or ground observations were used for composition counts. Observers were able to detect on black and white negatives over 95 percent of caribou counted from a helicopter flying at low altitude over the same area; photo scale varied between = 1:3 600 and 1:6 000. Sampling units covering less than 15-20 ha were the best for sampling caribou distribution on calving grounds, where density generally averaged » 10 individuals-km"2. Around 90 percent of caribou on calving grounds were females; others were mostly yearling males. During the 1-2 day photographic census, 64 to 77 percent of the females were present on the calving areas. Summer survival exceeded 95 percent in three summers. In autumn, females composed between 45 and 54 percent of each herd. The Rivière George herd was estimated at 682 000 individuals (± 36%; alpha = 0.10 in 1988. This estimate was imprecise due to insufficiens sample size for measuring animal density on the calving ground and for determining proportion of females on the calving ground at the time of the photo census. To improve precision and reduce cost, it is proposed to estimate herd size of tundra caribou in one step, using only aerial photos in early June without telemetry.

  4. Cover crops to improve soil health and pollinator habitat in nut orchards

    Science.gov (United States)

    Jerry. Van Sambeek

    2017-01-01

    Recently several national programs have been initiated calling for improving soil health and creating pollinator habitat using cover crops. Opportunities exist for nut growers to do both with the use of cover crops in our nut orchards. Because we can include perennial ground covers as cover crops, we have even more choices than landowners managing cover crops during...

  5. Ground Wars

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis

    Political campaigns today are won or lost in the so-called ground war--the strategic deployment of teams of staffers, volunteers, and paid part-timers who work the phones and canvass block by block, house by house, voter by voter. Ground Wars provides an in-depth ethnographic portrait of two...... infrastructures that utilize large databases with detailed individual-level information for targeting voters, and armies of dedicated volunteers and paid part-timers. Nielsen challenges the notion that political communication in America must be tightly scripted, controlled, and conducted by a select coterie...... of professionals. Yet he also quashes the romantic idea that canvassing is a purer form of grassroots politics. In today's political ground wars, Nielsen demonstrates, even the most ordinary-seeming volunteer knocking at your door is backed up by high-tech targeting technologies and party expertise. Ground Wars...

  6. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    is landscaped in order to fit into the surrounding area/environment or meet specific plans for the final use of the landfill. To fulfill the above listed requirements landfill covers are often multicomponent systems which are placed directly on top of the waste. The top cover may be placed immediately after...... the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... however, top covers may be the only environmental protection measure. In some landfill regulations (for instance the Subtitle D landfills receiving municipal solid waste in the USA) it is required to minimize infiltration into the waste layers. Therefore top covers containing liner components...

  7. Percent Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forests provide economic and ecological value. High percentages of forest cover (FORPCT) generally indicate healthier ecosystems and cleaner surface water. More...

  8. Saturated Domino Coverings

    CERN Document Server

    Buchanan, Andrew; Ryba, Alex

    2011-01-01

    A domino covering of a board is saturated if no domino is redundant. We introduce the concept of a fragment tiling and show that a minimal fragment tiling always corresponds to a maximal saturated domino covering. The size of a minimal fragment tiling is the domination number of the board. We define a class of regular boards and show that for these boards the domination number gives the size of a minimal X-pentomino covering. Natural sequences that count maximal saturated domino coverings of square and rectangular boards are obtained. These include the new sequences A193764, A193765, A193766, A193767, and A193768 of OEIS.

  9. Percent Forest Cover (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forests provide economic and ecological value. High percentages of forest cover (FORPCTFuture) generally indicate healthier ecosystems and cleaner surface water....

  10. Root characteristics of cover crops and their erosion-reducing potential during concentrated runoff

    Science.gov (United States)

    de Baets, S.; Poesen, J.

    2009-04-01

    In the loam region in central Belgium, a lot of research has been conducted on the effects of cover crops for preventing splash and interrill erosion and on their nutrient pumping effectiveness. As this is a very effective erosion and environment conservation technique, planting cover crops during the winter season is widely applied in the loess belt. Most of these cover crops freeze at the beginning of the winter period. Consequently, the above-ground biomass becomes less effective in protecting the soil from water erosion. Apart from the effects of the above-ground biomass in protecting the soil against raindrop impacts and reducing flow velocities by the retarding effects of their stems, plant roots also play an important role in improving soil strength. Previous research showed that roots contribute to a large extent to the resistance of topsoils against concentrated flow erosion. Unfortunately, information on root properties of common cover crops (e.g. Sinapis alba, Phacelia tanacetifoli, Lolium perenne, Avena sativa, Secale cereale, Raphanus sativus subsp. oleiferus) is very scarce. Therefore, root density distribution with depth and their erosion-reducing effects during concentrated flow erosion were assessed by conducting root auger measurements and concentrated flow experiments at the end of the growth period (December). The preliminary results indicate that the studied cover crops are not equally effective in preventing soil loss by concentrated flow erosion at the end of the growing season. Cover crops with thick roots, such as Sinapis alba and Raphanus sativus subsp. oleiferus are less effective than cover crops with fine-branched roots such as Phacelia tanacetifoli, Lolium perenne (Ryegrass), Avena sativa (Oats) and Secale cereale (Rye) in preventing soil losses by concentrated flow erosion. These results enable soil managers to select the most suitable crops and maximize soil protection.

  11. Land Cover Characterization Program

    Science.gov (United States)

    ,

    1997-01-01

    The U.S. Geological Survey (USGS) has a long heritage of leadership and innovation in land use and land cover mapping. The USGS Anderson system defined the principles for land use and land cover mapping that have been the model both nationally and internationally for more than 20 years. The Land Cover Characterization Program (LCCP) is founded on the premise that the Nation's needs for land cover and land use data are diverse and increasingly sophisticated. The range of projects, programs, and organizations that use land cover data to meet their planning, management, development, and assessment objectives has expanded significantly. The reasons for this are numerous, and include the improved capabilities provided by geographic information systems, better and more data-intensive analytic models, and increasing requirements for improved information for decision making. The overall goals of the LCCP are to:

  12. Land Cover Trends Project

    Science.gov (United States)

    Acevedo, William

    2006-01-01

    The Land Cover Trends Project is designed to document the types, rates, causes, and consequences of land cover change from 1973 to 2000 within each of the 84 U.S. Environmental Protection Agency (EPA) Level III ecoregions that span the conterminous United States. The project's objectives are to: * Develop a comprehensive methodology using probability sampling and change analysis techniques and Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), and Enhanced Thematic Mapper (ETM) data for estimating regional land cover change. * Characterize the spatial and temporal characteristics of conterminous U.S. land cover change for five periods from 1973 to 2000 (nominally 1973, 1980, 1986, 1992, and 2000). * Document the regional driving forces and consequences of change. * Prepare a national synthesis of land cover change.

  13. Flat covers of modules

    CERN Document Server

    Xu, Jinzhong

    1996-01-01

    Since the injective envelope and projective cover were defined by Eckmann and Bas in the 1960s, they have had great influence on the development of homological algebra, ring theory and module theory. In the 1980s, Enochs introduced the flat cover and conjectured that every module has such a cover over any ring. This book provides the uniform methods and systematic treatment to study general envelopes and covers with the emphasis on the existence of flat cover. It shows that Enochs' conjecture is true for a large variety of interesting rings, and then presents the applications of the results. Readers with reasonable knowledge in rings and modules will not have difficulty in reading this book. It is suitable as a reference book and textbook for researchers and graduate students who have an interest in this field.

  14. Manhole cover point locations across Guam's developed areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a point feature dataset with points across Guam's developed areas. The points represent manhole cover locations, ground elevation and manhole access depth.

  15. Land Cover Trends Geotagged Photography: 1999-2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) Land Cover Trends field photography collection is a national-scale, ground-reference dataset which initially served as a...

  16. Propagation of Sound Through the Atmosphere: Effects of Ground Cover

    Science.gov (United States)

    1978-06-19

    surface. The impedance measurements were limited to the -f -quency range 220 Hz to 1000 Hz due to the experimental saometry. In this region, however...frequency limit of 100 Hz. In this range, the surface wave predicted by the theory used to analyze the data was not calculated to be a significant fraction...RETURN rND FUNCION EAST611101,D31*1 DIME~ýIOW 11M(4 LEAST52 =IS MAE IS BXZST QUALITY FRLI=40 C D)UNA4I𔃻 AS TEVFITF 1,FD)AN4fN C(~r PHECTLO T( US AI

  17. BRS Centauro – oat cultivar for ground cover and grazing

    Directory of Open Access Journals (Sweden)

    Alfredo do Nascimento Junior

    2015-04-01

    Full Text Available Plants and seeds of oat cultivar BRS Centauro, of the species Avena brevis Roth., are highly uniform. The crop cycle is long, the suitability as fodder excellent, and leaf production particularly high, resulting in better quality forage than that of the black oat forage controls.

  18. Analysis of Vegetative on Six Different Landfill Cover Profiles in an Arid Environment.

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, Stephen F.; McClellan, Yvonne; Reavis, Bruce A.; Dwyer, Brian P.; Newman, Gretchen; Wolters, Gale

    2005-05-01

    A large-scale field demonstration comparing final landfill cover designs was constructed and monitored at Sandia National Laboratories in Albuquerque, New Mexico. Two conventional designs (a RCRA Subtitle 'D' Soil Cover and a RCRA Subtitle 'C' Compacted Clay Cover) were constructed side-by-side with four alternative cover test plots designed for arid environments. The demonstration was intended to evaluate the various cover designs based on their respective water balance performance, ease and reliability of construction, and cost. A portion of this project involves the characterization of vegetation establishment and growth on the landfill covers. The various prototype landfill covers were expected to have varying flux rates (Dwyer et al 2000). The landfill covers were further expected to influence vegetation establishment and growth, which may impact site erosion potential and long-term site integrity. Objectives of this phase were to quantify the types of plants occupying each site, the percentage of ground covered by these plants, the density (number of plants per unit area) of plants, and the plant biomass production. The results of this vegetation analysis are presented in this report.3 DRAFT07/06/14AcknowledgementsWe would like to thank all technical and support staff from Sandia and the USDA Forest Service's Rocky Mountain Station not included in the authors' list of this document for their valuable contributions to this research. We would also like to acknowledge the Department of Energy's Subsurface Contaminants Focus Area for funding this work.4

  19. Covering folded shapes

    Directory of Open Access Journals (Sweden)

    Oswin Aichholzer

    2014-05-01

    Full Text Available Can folding a piece of paper flat make it larger? We explore whether a shape S must be scaled to cover a flat-folded copy of itself. We consider both single folds and arbitrary folds (continuous piecewise isometries \\(S\\to\\mathbb{R}^2\\. The underlying problem is motivated by computational origami, and is related to other covering and fixturing problems, such as Lebesgue's universal cover problem and force closure grasps. In addition to considering special shapes (squares, equilateral triangles, polygons and disks, we give upper and lower bounds on scale factors for single folds of convex objects and arbitrary folds of simply connected objects.

  20. Swift Foxes and Ideal Free Distribution: Relative Influence of Vegetation and Rodent Prey Base on Swift Fox Survival, Density, and Home Range Size

    Science.gov (United States)

    2012-01-01

    into estimates of percent basal cover, percent bare ground, percent litter ( dead material), and mean shrub and grass height. Shrub density was calculated...2003. [39] W. S. Longland and M. V. Price, “Direct observations of owls and heteromyid rodents: can predation risk explain microhab- itat use?” Ecology, vol. 72, no. 6, pp. 2261–2273, 1991.

  1. Adding structure to land cover - using fractional cover to study animal habitat use.

    Science.gov (United States)

    Bevanda, Mirjana; Horning, Ned; Reineking, Bjoern; Heurich, Marco; Wegmann, Martin; Mueller, Joerg

    2014-01-01

    Linking animal movements to landscape features is critical to identify factors that shape the spatial behaviour of animals. Habitat selection is led by behavioural decisions and is shaped by the environment, therefore the landscape is crucial for the analysis. Land cover classification based on ground survey and remote sensing data sets are an established approach to define landscapes for habitat selection analysis. We investigate an approach for analysing habitat use using continuous land cover information and spatial metrics. This approach uses a continuous representation of the landscape using percentage cover of a chosen land cover type instead of discrete classes. This approach, fractional cover, captures spatial heterogeneity within classes and is therefore capable to provide a more distinct representation of the landscape. The variation in home range sizes is analysed using fractional cover and spatial metrics in conjunction with mixed effect models on red deer position data in the Bohemian Forest, compared over multiple spatio-temporal scales. We analysed forest fractional cover and a texture metric within each home range showing that variance of fractional cover values and texture explain much of variation in home range sizes. The results show a hump-shaped relationship, leading to smaller home ranges when forest fractional cover is very homogeneous or highly heterogeneous, while intermediate stages lead to larger home ranges. The application of continuous land cover information in conjunction with spatial metrics proved to be valuable for the explanation of home-range sizes of red deer.

  2. Analysis of Causes of Karst Collapse and the Corresponding Countermeasures During the Running of Ground Source Heat Pump in the Covered Karst Areas%覆盖型岩溶区地下水地源热泵工程岩溶塌陷成因及对策研究

    Institute of Scientific and Technical Information of China (English)

    段启杉; 曹振东; 孟凡涛; 宋小庆

    2015-01-01

    地下水地源热泵工程是抽取地下水,以地下水为换热介质,提取能量之后全部回灌于含水层中。因此地下水地源热泵是改变地下水局部水位高程,整体上不影响地下水流场的变化。覆盖型岩溶区地质环境承载力较差,地下水的开发利用过程,可能加强诱发岩溶塌陷的因素,发生岩溶塌陷。在地下水地源热泵的建设和运行中,控制水位降深、尽量避免水位波动和瞬间水位变化过大等措施,达到预防岩溶塌陷的目的。而岩溶塌陷预防措施的研究给覆盖型岩溶区地下水地源热泵的建设和运行提供技术支撑。%Ground source heat pump engineering is pumping groundwater, groundwater as heat transfer medium, extract the energy after full recharge in the aquifer. So the groundwater source heat pump is to change the local groundwater level elevation, on the whole does not affect the change of the groundwater flow field. Covered karst area with poor bearing capacity of geological envi-ronment, the development and utilization of groundwater, karst collapse could strengthen induced factors, karst collapse occurred. In groundwater in the construction and operation of ground source heat pump, control the water level drawdown, avoid water level fluctuation and instantaneous water level change is too big, so as to achieve the purpose of prevention of karst collapse, and preven-tive measures of karst collapse research covered karst area groundwater source heat pump with pumping and technical support for the construction and operation.

  3. Differential productivity of Bristol Bay spawning grounds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Bristol Bay escapement surveys covering a period of several years show that, irrespective of fluctuations in total numbers on a system, certain grounds display a...

  4. Measurements of radar ground returns

    NARCIS (Netherlands)

    Loor, G.P. de

    1974-01-01

    The ground based measurement techniques for the determination of the radar back-scatter of vegetation and soils as used in The Netherlands will be described. Two techniques are employed: one covering a large sample area (> 1000 m2) but working at low grazing angels only and one (short range) coverin

  5. Percent Wetland Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be...

  6. Percent of Impervious Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — High amounts of impervious cover (parking lots, rooftops, roads, etc.) can increase water runoff, which may directly enter surface water. Runoff from roads often...

  7. Percent Wetland Cover (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be...

  8. GAP Land Cover - Image

    Data.gov (United States)

    Minnesota Department of Natural Resources — This raster dataset is a simple image of the original detailed (1-acre minimum), hierarchically organized vegetation cover map produced by computer classification of...

  9. GAP Land Cover - Vector

    Data.gov (United States)

    Minnesota Department of Natural Resources — This vector dataset is a detailed (1-acre minimum), hierarchically organized vegetation cover map produced by computer classification of combined two-season pairs of...

  10. Projected 2020 Land Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Projected 2020 land cover was developed to provide one scenario of development in the year 2020. It was used to generate several metrics to compare to 1992 metrics...

  11. Fabrication of TiO2-NTs and TiO2-NTs covered honeycomb lattice and investigation of carrier densities in I-/I3- electrolyte by electrochemical impedance spectroscopy

    Science.gov (United States)

    Baran, Evrim; Yazıcı, Birgül

    2015-12-01

    The TiO2 nanotubes (NTs) were produced by one-step (1S) and two-step (2S) anodization technique. Effects of various anodization potential and times on the growth of TiO2-NTs were investigated by using Field Emission-Scanning Electron Microscopy (FE-SEM). The crystal structure of the electrodes was determined with X-ray powder diffractometry (XRD). The most suitable potential and time for TiO2-NTs obtained by both of anodization methods were found to be 21 V and 4 h. XRD results indicated that 2S anodization technique provided better crystallinity. The electrochemical behaviors of the electrodes in acetonitrile electrolyte contained I-/I3- were examined by utilizing electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) techniques. Electrochemical results showed that 2S anodization technique increases the carrier densities (ND) value of TiO2-NTs, and flat band potential is shifted by 50 mV to more negative values.

  12. Intrinsic-Density Functionals

    CERN Document Server

    Engel, J

    2006-01-01

    The Hohenberg-Kohn theorem and Kohn-Sham procedure are extended to functionals of the localized intrinsic density of a self-bound system such as a nucleus. After defining the intrinsic-density functional, we modify the usual Kohn-Sham procedure slightly to evaluate the mean-field approximation to the functional, and carefully describe the construction of the leading corrections for a system of fermions in one dimension with a spin-degeneracy equal to the number of particles N. Despite the fact that the corrections are complicated and nonlocal, we are able to construct a local Skyrme-like intrinsic-density functional that, while different from the exact functional, shares with it a minimum value equal to the exact ground-state energy at the exact ground-state intrinsic density, to next-to-leading order in 1/N. We briefly discuss implications for real Skyrme functionals.

  13. SpinSat Mission Ground Truth Characterization

    Science.gov (United States)

    2014-09-01

    SpinSat Mission Ground Truth Characterization Andrew Nicholas, Ted Finne, Ivan Galysh, Anthony Mai, Jim Yen Naval Research Laboratory, Washington...mission overview, ground truth characterization and unique SSA observation opportunities of the mission. 1. MISSION CONCEPT The Naval Research...2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE SpinSat Mission Ground Truth Characterization 5a. CONTRACT

  14. Climate under cover

    CERN Document Server

    Takakura, Tadashi

    2002-01-01

    1.1. INTRODUCTION Plastic covering, either framed or floating, is now used worldwide to protect crops from unfavorable growing conditions, such as severe weather and insects and birds. Protected cultivation in the broad sense, including mulching, has been widely spread by the innovation of plastic films. Paper, straw, and glass were the main materials used before the era of plastics. Utilization of plastics in agriculture started in the developed countries and is now spreading to the developing countries. Early utilization of plastic was in cold regions, and plastic was mainly used for protection from the cold. Now plastic is used also for protection from wind, insects and diseases. The use of covering techniques started with a simple system such as mulching, then row covers and small tunnels were developed, and finally plastic houses. Floating mulch was an exception to this sequence: it was introduced rather recently, although it is a simple structure. New development of functional and inexpensive films trig...

  15. Reusable pipe flange covers

    Energy Technology Data Exchange (ETDEWEB)

    Holden, James Elliott (Simpsonville, SC); Perez, Julieta (Houston, TX)

    2001-01-01

    A molded, flexible pipe flange cover for temporarily covering a pipe flange and a pipe opening includes a substantially round center portion having a peripheral skirt portion depending from the center portion, the center portion adapted to engage a front side of the pipe flange and to seal the pipe opening. The peripheral skirt portion is formed to include a plurality of circumferentially spaced tabs, wherein free ends of the flexible tabs are formed with respective through passages adapted to receive a drawstring for pulling the tabs together on a back side of the pipe flange.

  16. Assimilation of satellite information in a snowpack model to improve characterization of snow cover for runoff simulation and forecasting

    Directory of Open Access Journals (Sweden)

    L. S. Kuchment

    2009-08-01

    Full Text Available A new technique for constructing spatial fields of snow characteristics for runoff simulation and forecasting is presented. The technique incorporates satellite land surface monitoring data and available ground-based hydrometeorological measurements in a physical based snowpack model. The snowpack model provides simulation of temporal changes of the snow depth, density and water equivalent (SWE, accounting for snow melt, sublimation, refreezing melt water and snow metamorphism processes with a special focus on forest cover effects. The model was first calibrated against available ground-based snow measurements and then was applied to calculate the spatial distribution of snow characteristics using satellite data and interpolated ground-based meteorological data. The remote sensing data used in the model consist of products derived from observations of MODIS and AMSR-E instruments onboard Terra and Aqua satellites. They include daily maps of snow cover, snow water equivalent (SWE, land surface temperature, and weekly maps of surface albedo. Maps of land cover classes and tree cover fraction derived from NOAA AVHRR were used to characterize the vegetation cover. The developed technique was tested over a study area of approximately 200 000 km2 located in the European part of Russia (56° N to 60° N, and 48° E to 54° E. The study area comprises the Vyatka River basin with the catchment area of 124 000 km2. The spatial distributions of SWE, obtained with the coupled model, as well as solely from satellite data were used as the inputs in a physically-based model of runoff generation to simulate runoff hydrographs on the Vyatka river for spring seasons of 2003, 2005. The comparison of simulated hydrographs with the observed ones has shown that suggested procedure gives a higher accuracy of snow cover spatial distribution representation and hydrograph simulations than the direct use of satellite SWE data.

  17. Assimilation of satellite information in a snowpack model to improve characterization of snow cover for runoff simulation and forecasting

    Science.gov (United States)

    Kuchment, L. S.; Romanov, P.; Gelfan, A. N.; Demidov, V. N.

    2009-08-01

    A new technique for constructing spatial fields of snow characteristics for runoff simulation and forecasting is presented. The technique incorporates satellite land surface monitoring data and available ground-based hydrometeorological measurements in a physical based snowpack model. The snowpack model provides simulation of temporal changes of the snow depth, density and water equivalent (SWE), accounting for snow melt, sublimation, refreezing melt water and snow metamorphism processes with a special focus on forest cover effects. The model was first calibrated against available ground-based snow measurements and then was applied to calculate the spatial distribution of snow characteristics using satellite data and interpolated ground-based meteorological data. The remote sensing data used in the model consist of products derived from observations of MODIS and AMSR-E instruments onboard Terra and Aqua satellites. They include daily maps of snow cover, snow water equivalent (SWE), land surface temperature, and weekly maps of surface albedo. Maps of land cover classes and tree cover fraction derived from NOAA AVHRR were used to characterize the vegetation cover. The developed technique was tested over a study area of approximately 200 000 km2 located in the European part of Russia (56° N to 60° N, and 48° E to 54° E). The study area comprises the Vyatka River basin with the catchment area of 124 000 km2. The spatial distributions of SWE, obtained with the coupled model, as well as solely from satellite data were used as the inputs in a physically-based model of runoff generation to simulate runoff hydrographs on the Vyatka river for spring seasons of 2003, 2005. The comparison of simulated hydrographs with the observed ones has shown that suggested procedure gives a higher accuracy of snow cover spatial distribution representation and hydrograph simulations than the direct use of satellite SWE data.

  18. 'Grounded' Politics

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2012-01-01

    play within one particular neighbourhood: Nørrebro in the Danish capital, Copenhagen. The article introduces the concept of grounded politics to analyse how groups of Muslim immigrants in Nørrebro use the space, relationships and history of the neighbourhood for identity political statements....... The article further describes how national political debates over the Muslim presence in Denmark affect identity political manifestations within Nørrebro. By using Duncan Bell’s concept of mythscape (Bell, 2003), the article shows how some political actors idealize Nørrebro’s past to contest the present...

  19. Responses of predatory invertebrates to seeding density and plant species richness in experimental tallgrass prairie restorations

    Science.gov (United States)

    Nemec, Kristine T.; Allen, Craig R.; Danielson, Stephen D.; Helzer, Christopher J.

    2014-01-01

    In recent decades, agricultural producers and non-governmental organizations have restored thousands of hectares of former cropland in the central United States with native grasses and forbs. However, the ability of these grassland restorations to attract predatory invertebrates has not been well documented, even though predators provide an important ecosystem service to agricultural producers by naturally regulating herbivores. This study assessed the effects of plant richness and seeding density on the richness and abundance of surface-dwelling (ants, ground beetles, and spiders) and aboveground (ladybird beetles) predatory invertebrates. In the spring of 2006, twenty-four 55 m × 55 m-plots were planted to six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Natural Resources Conservation Service Conservation Reserve Program mix, CP25), at low and high seeding densities. Ants, ground beetles, and spiders were sampled using pitfall traps and ladybird beetles were sampled using sweep netting in 2007–2009. The abundance of ants, ground beetles, and spiders showed no response to seed mix richness or seeding density but there was a significant positive effect of richness on ladybird beetle abundance. Seeding density had a significant positive effect on ground beetle and spider species richness and Shannon–Weaver diversity. These results may be related to differences in the plant species composition and relative amount of grass basal cover among the treatments rather than richness.

  20. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jian-Ying; Ibragimov, Rashid

    2013-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting ...

  1. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jiong; Ibragimov, Rashid

    2015-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting ...

  2. Covering All Options

    Science.gov (United States)

    Kennedy, Mike

    2011-01-01

    The day a school opens its doors for the first time, the flooring will be new and untarnished. When the flooring is in such pristine condition, many flooring materials--carpeting, vinyl, terrazzo, wood or some other surface--will look good. But school and university planners who decide what kind of material covers the floors of their facilities…

  3. CORINE Land Cover 2006

    DEFF Research Database (Denmark)

    Stjernholm, Michael

    "CORINE land cover" er en fælleseuropæisk kortlægning af arealanvendelse/arealdække. Arealanvendelse/arealdække er i Danmark kortlagt efter CORINE metode og klasseopdeling med satellitbilleder fra 3 forskellige tidsperioder, fra begyndelsen af 1990'erne (CLC90), fra år 2000 (CLC2000) og fra år 2006...

  4. CORINE Land Cover 2006

    DEFF Research Database (Denmark)

    Stjernholm, Michael

    "CORINE land cover" er en fælleseuropæisk kortlægning af arealanvendelse/arealdække. Arealanvendelse/arealdække er i Danmark kortlagt efter CORINE metode og klasseopdeling med satellitbilleder fra 3 forskellige tidsperioder, fra begyndelsen af 1990'erne (CLC90), fra år 2000 (CLC2000) og fra år 2006...

  5. Spatial and temporal variability of grass cover in two olive grove catchments on contrasting soil types

    Science.gov (United States)

    Aguilera, Laura; Taguas, Encarnación V.; Gimeno, Enrique; Gómez, José A.

    2013-04-01

    mechanically killed by several tractor passes. Ground cover was evaluated by a field surveys (4 per year) in which the same areas were measured at an approximate density of 4 samples/ha. In each point, over a 0.25 m2 area ground cover was measured using photographs, then point measurements were interpolated using method of Inverse Distance Weighting methods, to generate continuous distribution maps. The spatial and temporal evolution of ground cover in both farms presented a notably different patterns in both farms. In "La Conchuela", maximum values of cover can be reached in winter (61%, Dec-2011) while in "Arroyo Blanco", the maximum values were observed during the spring (50% May-2011) and are dramatically lower in the seasons of summer and autumn. These differences are justified by the influence of the management, the precipitation regime and the soil qualities such as the depth. On the other hand, the large spatial variability of ground cover measurements in both catchments, with coefficients of variation between 41 and 167%, was mainly led by the topography. In both farms the highest values of ground cover were found in those areas with deeper soils located in also in converging areas where surface runoff is concentrated. In the highest and shallowest area, soil management operations might improve the establishment of the vegetation as well as to address the growing in the most erosive periods. Finally, the impact of grass cover on the hydrological and erosive responses in the catchment is also discussed. References Aguilera, L. 2012. Estudio de cubiertas vegetales para el control de la erosión en olivar. Evaluación espacio-temporal en dos fincas comerciales, y exploración de nuevas opciones de cubiertas. Master Thesis. University of Cordoba. Gómez, J.A., Giráldez, J.V. Erosión y degradación de suelos. In: Sostenibilidad de la producción de olivar en Andalucía. Gómez, J.A. (Editor). Junta de Andalucía. Sevilla, p. 45-86. Gómez, J.A., Sobrinho, T.A., Gir

  6. Dielectric Covered Planar Antennas

    Science.gov (United States)

    Llombart Juan, Nuria (Inventor); Lee, Choonsup (Inventor); Chattopadhyay, Goutam (Inventor); Gill, John J. (Inventor); Skalare, Anders J. (Inventor); Siegel, Peter H. (Inventor)

    2014-01-01

    An antenna element suitable for integrated arrays at terahertz frequencies is disclosed. The antenna element comprises an extended spherical (e.g. hemispherical) semiconductor lens, e.g. silicon, antenna fed by a leaky wave waveguide feed. The extended spherical lens comprises a substantially spherical lens adjacent a substantially planar lens extension. A couple of TE/TM leaky wave modes are excited in a resonant cavity formed between a ground plane and the substantially planar lens extension by a waveguide block coupled to the ground plane. Due to these modes, the primary feed radiates inside the lens with a directive pattern that illuminates a small sector of the lens. The antenna structure is compatible with known semiconductor fabrication technology and enables production of large format imaging arrays.

  7. Singular coverings of toposes

    CERN Document Server

    Bunge, Marta

    2006-01-01

    The self-contained theory of certain singular coverings of toposes called complete spreads, that is presented in this volume, is a field of interest to topologists working in knot theory, as well as to various categorists. It extends the complete spreads in topology due to R. H. Fox (1957) but, unlike the classical theory, it emphasizes an unexpected connection with topos distributions in the sense of F. W. Lawvere (1983). The constructions, though often motivated by classical theories, are sometimes quite different from them. Special classes of distributions and of complete spreads, inspired respectively by functional analysis and topology, are studied. Among the former are the probability distributions; the branched coverings are singled out amongst the latter. This volume may also be used as a textbook for an advanced one-year graduate course introducing topos theory with an emphasis on geometric applications. Throughout the authors emphasize open problems. Several routine proofs are left as exercises, but...

  8. On directed coverings

    DEFF Research Database (Denmark)

    Fajstrup, Lisbeth

    In [1], we study coverings in the setting of directed topology. Unfortunately, there is a condition missing in the definition of a directed covering. Some of the results in [1] require this extra condition and in fact it was claimed to follow from the original definition. It is the purpose...... of this note to give the right definition and point out how this affects the statements in that paper. Moreover, we give an example of a dicovering in the sense of [1], which does not satisfy the extra condition. Fortunately, with the extra condition, the subsequent results are now correct. [1] L. Fajstrup......, Dicovering spaces, Homology Homotopy Appl. 5 (2003), no. 2, 1-17....

  9. Modeling and synthesis of strong ground motion

    Indian Academy of Sciences (India)

    S T G Raghu Kanth

    2008-11-01

    Success of earthquake resistant design practices critically depends on how accurately the future ground motion can be determined at a desired site. But very limited recorded data are available about ground motion in India for engineers to rely upon. To identify the needs of engineers, under such circumstances, in estimating ground motion time histories, this article presents a detailed review of literature on modeling and synthesis of strong ground motion data. In particular, modeling of seismic sources and earth medium, analytical and empirical Green’s functions approaches for ground motion simulation, stochastic models for strong motion and ground motion relations are covered. These models can be used to generate realistic near-field and far-field ground motion in regions lacking strong motion data. Numerical examples are shown for illustration by taking Kutch earthquake-2001 as a case study.

  10. Covering R-trees

    CERN Document Server

    Berestovskii, V N

    2007-01-01

    We show that every inner metric space X is the metric quotient of a complete R-tree via a free isometric action, which we call the covering R-tree of X. The quotient mapping is a weak submetry (hence, open) and light. In the case of compact 1-dimensional geodesic space X, the free isometric action is via a subgroup of the fundamental group of X. In particular, the Sierpin'ski gasket and carpet, and the Menger sponge all have the same covering R-tree, which is complete and has at each point valency equal to the continuum. This latter R-tree is of particular interest because it is "universal" in at least two senses: First, every R-tree of valency at most the continuum can be isometrically embedded in it. Second, every Peano continuum is the image of it via an open light mapping. We provide a sketch of our previous construction of the uniform universal cover in the special case of inner metric spaces, the properties of which are used in the proof.

  11. Seedling density according to structure, dominance and understory cover in old-growth forest stands of the evergreen forest type in the coastal range of Chile Densidad de plántulas de acuerdo a la estructura, dominancia y cobertura del sotobosque en bosques siempreverdes adultos en la cordillera de la Costa de Chile

    Directory of Open Access Journals (Sweden)

    Pablo J. Donoso

    2005-03-01

    Full Text Available Securing timely regeneration is essential in maintaining the long-term ecological or silvicultural functions and values of forests. Its establishment, in turn, depends on many factors, including the structure and composition of the forest itself. Available information shows that seedling density varies greatly across the evergreen forest type in Chile. Yet stand variables that may affect the establishment of advance regeneration have not been studied. To that end, we evaluated seven stands of the coastal range, within the northern part of the evergreen forest type (39°14'-40°16' S. We documented understory cover, tree density and dominance, and stand structure, and used the information to assess their effects over seedling density. Findings indicate that Laurelia philippiana was the dominant canopy and regenerating species in these stands. Also, seedling density was significantly greater in stands at lower elevations where shade-tolerant Aextoxicon punctatum was important. Chusquea spp. and Lophosoria quadripinnata, both understory species, had a significant negative effect on seedling density. Basal area and canopy cover, per se, showed little relationship with seedling density. Vertical structure, evaluated through a crown index, had a significant relationship with seedling density, but the direction depended on the species (e.g., L. philippiana and A. punctatum and the diameter structure within our plots. Fitted models that included these variables were highly significant, and in most cases their significance increased considerably (14 to 26 % when we accounted for the diameter structures of the plotsLa regeneración es esencial para mantener en el largo plazo las funciones y valores ecológicos o silviculturales de los bosques. Su establecimiento depende de varios factores, incluyendo la estructura y composición del bosque. La información disponible indica que existe una gran variabilidad en la densidad de plántulas a través de la

  12. Studies on deposition, adhesion and resuspension of radioactive substances on the ground surface and ground cover

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, Susumu; Kurihara, Kazuo [Meteorological Research Inst., Tsukuba, Ibaraki (Japan)

    1999-03-01

    After the Chernobyl` nuclear power plant accident, resuspension of radioactive nuclei into the atmosphere is recognized as the one of the important processes that must be considered in the estimation of inhalation doses to humans. In this study, resuspensions of particles from soil and grass have been studied. The resuspension of particles from bare soil was modelized by using Shao`s method. The resuspension of particles from grass was studied by a wind tunnel and a field experiment. Dependencies of the resuspension rate on time and on friction velocity were obtained clearly. And it was also found that the other meteorological parameters, such as temperature, relative humidity, solar radiation and condensation, affected the resuspension rate in the field. (author)

  13. Estimation of Soil Erosion Rates in Oil Palm Plantation with Different Land Cover

    Science.gov (United States)

    Sahat, S.; Yusop, Z.; Askari, M.; Ziegler, A. D.

    2016-07-01

    Soil losses from hill slopes in oil palm plantation in Sedenak Estate, Johor were measured using runoff plot and rainfall simulator. The plot was designed to be removable but the size was fixed at 8 x 3.75m. Four types of surface covers were investigated for the plots, i.e. half bare soil and half grass cover (HGC), half bare soil and half dry frond (HDF), fully grass cover (FG), and fully bare soil (BS). The influence of initial soil moisture, saturated hydraulics conductivity, Ks, bulk density and slope on rates of soil loss were also evaluated. The rainfall simulator produced rainfall intensities between 90 and 160 mm/hr with durations from 45 to 60 min per run. BS plot exhibited the highest Ks value among all plots but the percentage of initial soil moisture on this surface was low. BS plot recorded the highest runoff coefficient (C) and soil loss values of 73.6 ± 4 percent and 5.26 ± 3.2 t/ha respectively, while the lowest was from plot FG with 41.7 ± 5.7 percent and soil loss of 2.85 ± 2.1 t/ha. Meanwhile, the results suggested that the ground cover had the ability to reduce soil loss by 67% and 17%, respectively for plots BS-HGC and BS-HDF. Overall, soil erosion control such as surface is effective measures in reducing level of runoff and soil erosion.

  14. Covered Clause Elimination

    CERN Document Server

    Heule, Marijn; Biere, Armin

    2010-01-01

    Generalizing the novel clause elimination procedures developed in [M. Heule, M. J\\"arvisalo, and A. Biere. Clause elimination procedures for CNF formulas. In Proc. LPAR-17, volume 6397 of LNCS, pages 357-371. Springer, 2010.], we introduce explicit (CCE), hidden (HCCE), and asymmetric (ACCE) variants of a procedure that eliminates covered clauses from CNF formulas. We show that these procedures are more effective in reducing CNF formulas than the respective variants of blocked clause elimination, and may hence be interesting as new preprocessing/simplification techniques for SAT solving.

  15. Mapping land cover gradients through analysis of hyper-temporal NDVI imagery

    NARCIS (Netherlands)

    Ali, A.; de Bie, C.A.J.M.; Skidmore, A.K.; Scarrott, R.G.; Hamad, A.A.; Venus, V.; Lymberakis, P.

    2013-01-01

    The green cover of the earth exhibits various spatial gradients that represent gradual changes in space of vegetation density and/or in species composition. To date, land cover mapping methods differentiate at best, mapping units with different cover densities and/or species compositions, but typica

  16. Mapping land cover gradients through analysis of hyper-temporal NDVI imagery

    NARCIS (Netherlands)

    Ali, A.; Bie, de C.A.J.M.; Skidmore, A.K.; Scarrott, R.G.; Hamad, A.A.; Venus, V.; Lymberakis, P.

    2013-01-01

    The green cover of the earth exhibits various spatial gradients that represent gradual changes in space of vegetation density and/or in species composition. To date, land cover mapping methods differentiate at best, mapping units with different cover densities and/or species compositions, but typica

  17. Covering walks in graphs

    CERN Document Server

    Fujie, Futaba

    2014-01-01

    Covering Walks  in Graphs is aimed at researchers and graduate students in the graph theory community and provides a comprehensive treatment on measures of two well studied graphical properties, namely Hamiltonicity and traversability in graphs. This text looks into the famous Kӧnigsberg Bridge Problem, the Chinese Postman Problem, the Icosian Game and the Traveling Salesman Problem as well as well-known mathematicians who were involved in these problems. The concepts of different spanning walks with examples and present classical results on Hamiltonian numbers and upper Hamiltonian numbers of graphs are described; in some cases, the authors provide proofs of these results to illustrate the beauty and complexity of this area of research. Two new concepts of traceable numbers of graphs and traceable numbers of vertices of a graph which were inspired by and closely related to Hamiltonian numbers are introduced. Results are illustrated on these two concepts and the relationship between traceable concepts and...

  18. Holographic charge density waves

    CERN Document Server

    Donos, Aristomenis

    2013-01-01

    We show that strongly coupled holographic matter at finite charge density can exhibit charge density wave phases which spontaneously break translation invariance while preserving time-reversal and parity invariance. We show that such phases are possible within Einstein-Maxwell-dilaton theory in general spacetime dimensions. We also discuss related spatially modulated phases when there is an additional coupling to a second vector field, possibly with non-zero mass. We discuss how these constructions, and others, should be associated with novel spatially modulated ground states.

  19. Holographic charge density waves

    Science.gov (United States)

    Donos, Aristomenis; Gauntlett, Jerome P.

    2013-06-01

    We show that strongly coupled holographic matter at finite charge density can exhibit charge density wave phases which spontaneously break translation invariance while preserving time-reversal and parity invariance. We show that such phases are possible within Einstein-Maxwell-dilaton theory in general spacetime dimensions. We also discuss related spatially modulated phases when there is an additional coupling to a second vector field, possibly with nonzero mass. We discuss how these constructions, and others, should be associated with novel spatially modulated ground states.

  20. Land Use and Land Cover - Montana Land Cover Framework 2013

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This statewide land cover theme is a baseline digital map of Montana's natural and human land cover. The baseline map is adapted from the Northwest ReGAP project...

  1. Sky cover from MFRSR observations: cumulus clouds

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-01-01

    Full Text Available The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their model clear-sky counterparts are two main components of a new method for estimating the fractional sky cover of different cloud types, including cumulus clouds. The performance of this method is illustrated using 1-min resolution data from ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR. The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM Climate Research Facility (ACRF Southern Great Plains (SGP site during the summer of 2007 and represent 13 days with cumulus clouds. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

  2. Cooling experiments using dummies covered by leaves.

    Science.gov (United States)

    Althaus, L; Stückradt, S; Henssge, C; Bajanowski, T

    2007-03-01

    One main method to estimate the time of death is the measurement of the body temperature. The cooling of a corpse depends on a number of conditions including the surroundings. In cases where the cooling conditions differ from the defined standard, a corrective factor is used to characterise the influence of clothing, air movement, the properties of the supporting base and the humidity. Nothing is known about the significance of other circumstances, for example of a tegument by leaves or wet leaves. Therefore, the cooling of dummies which were placed on a 2-cm-thick layer of wet/dry leaves and covered by a 10-cm-thick layer of leaves was investigated. Corrective factors of 1.0 for wet leaves on the ground and of 1.3 and 1.5 for drier leaves were found. If the dummies were additionally covered, corrective factors ranged between 1.8 and 2.7.

  3. Spatiotemporal analysis of the effects of forest covers on water yield in the Western Ghats of peninsular India

    Science.gov (United States)

    Singh, Sunita; Mishra, Arabinda

    2012-06-01

    SummaryBiotic interference has greatly disturbed the forest cover, the forest soils and, therefore, the hydrological functioning of the forest (Bonell and Bruijnzeel, 2005). Though widely debated, reduction in water yield (Water Yield: Total quantity of surface water that can be expected in a given period from a stream at the outlet of its catchment (Subramanya, 2008)) appears to be one such consequence. Scientific understanding of how this contentious issue affects the benefits of forests for water is critical to avoid unintended consequences (IUFRO, 2007). Gaps in research exist for tropical forest areas that are now a general mix of primary forest and secondary vegetation interspersed with patches cleared for agriculture or other non-forest uses (Bruijnzeel, 2004; Giambelluca, 2002). For this reason, research on spatiotemporal variations in the effects of a mix of primary forest (Primary Forests: Old forests with no or inconsequential human disturbance), mature secondary forests (Secondary Forests: Forests regenerating largely through natural processes after significant human and/or natural disturbance of the original forest vegetation at a single point in time or over an extended period, and displaying a major difference in forest structure and/or canopy species composition with respect to nearby primary forests on similar sites (Chokkalingam and Jong, 2001)) and disturbed forests (Disturbed Forests: Forests that have been exploited on moderate to large scale for timber, fuel wood, fodder, shifting cultivation and other tangible benefits. Reforestation activities may or may not have been undertaken in them) on runoff coefficients was conducted in four watersheds in the Western Ghats of peninsular India. Forest cover (Forest Cover: All lands with tree cover of canopy density of 10% and above when projected vertically on the horizontal ground with minimum areal extent of one Ha) significantly (0.01 forest cover, the Tulsi Watershed having mainly primary forests

  4. Allegheny County Land Cover Areas

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Land Cover dataset demarcates 14 land cover types by area; such as Residential, Commercial, Industrial, Forest, Agriculture, etc. If viewing this description on...

  5. Allegheny County Land Cover Areas

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Land Cover dataset demarcates 14 land cover types by area; such as Residential, Commercial, Industrial, Forest, Agriculture, etc. If viewing this description...

  6. Allegheny County Land Cover Areas

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Land Cover dataset demarcates 14 land cover types by area; such as Residential, Commercial, Industrial, Forest, Agriculture, etc. If viewing this description on...

  7. Space Constrained Dynamic Covering

    CERN Document Server

    Antonellis, Ioannis; Dughmi, Shaddin

    2009-01-01

    In this paper, we identify a fundamental algorithmic problem that we term space-constrained dynamic covering (SCDC), arising in many modern-day web applications, including ad-serving and online recommendation systems in eBay and Netflix. Roughly speaking, SCDC applies two restrictions to the well-studied Max-Coverage problem: Given an integer k, X={1,2,...,n} and I={S_1, ..., S_m}, S_i a subset of X, find a subset J of I, such that |J| <= k and the union of S in J is as large as possible. The two restrictions applied by SCDC are: (1) Dynamic: At query-time, we are given a query Q, a subset of X, and our goal is to find J such that the intersection of Q with the union of S in J is as large as possible; (2) Space-constrained: We don't have enough space to store (and process) the entire input; specifically, we have o(mn), sometimes even as little as O((m+n)polylog(mn)) space. The goal of SCDC is to maintain a small data structure so as to answer most dynamic queries with high accuracy. We present algorithms a...

  8. Dependences of longleaf pine (Pinus palustris) natural reproduction on environments above ground

    Institute of Scientific and Technical Information of China (English)

    Qiuju Guo; Dexiang Wang; Xunru Ai; Lan Yao

    2014-01-01

    We studied relations between natural seedling reproduction and above ground environment in a longleaf pine ecosystem. Forty-eight 0.05 ha circular plots were sampled under single-tree selection, group-tree selection and control stands in three main longleaf pine areas in south Alabama, USA. We measured six above-ground environment factors, viz. canopy closure, stand density, basal area, average tree height, understory cover and PAR under canopy. We employed forward, back-ward and stepwise selection regression to produce one model. Three main variables:canopy closure, stand density and basal area, were left in the model; light, PAR and understory cover were not incorporated into the model at the 0.10 significance level. Basal area was a positive pa-rameter, while canopy closure and stand density were negative parame-ters. Canopy closure was the main parameter in the model. The model proved to be meaningful, and has potential to provide useful guidance for future work.

  9. Ground state of a confined Yukawa plasma

    CERN Document Server

    Henning, C; Block, D; Bonitz, M; Golubnichiy, V; Ludwig, P; Piel, A

    2006-01-01

    The ground state of an externally confined one-component Yukawa plasma is derived analytically. In particular, the radial density profile is computed. The results agree very well with computer simulations on three-dimensional spherical Coulomb crystals. We conclude in presenting an exact equation for the density distribution for a confinement potential of arbitrary geometry.

  10. Cover crops and N credits

    Science.gov (United States)

    Cover crops often provide many short- and long-term benefits to cropping systems. Legume cover crops can significantly reduce the N fertilizer requirement of non-legume cash crops that follow. The objectives of this presentation were to: I) educate stakeholders about the potential benefits of cover ...

  11. Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in U.S. ground water used for drinking (simulation depth 50 meters) -- Input data set for population density (gwava-dw_popd)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents 1990 block group population density, in people per square kilometer, in the conterminous United States. This data set represents The data...

  12. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta Forests.

    Directory of Open Access Journals (Sweden)

    Anne C S McIntosh

    Full Text Available Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs and multiple carbon-source substrate-induced respiration (MSIR of the forest floor microbial community environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis showed that two above-ground (mean tree diameter, litter cover and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs properties were associated with variation in understory plant community composition. These results provide

  13. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests.

    Science.gov (United States)

    McIntosh, Anne C S; Macdonald, S Ellen; Quideau, Sylvie A

    2016-01-01

    Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

  14. On L-injective Covers

    Institute of Scientific and Technical Information of China (English)

    周德旭

    2004-01-01

    We use the class of L-injective modules to define L-injective covers, and provide the characterizations of L-injective covers by the properties of kernels of homomorphisms. We prove that the right L-noetherian right L-hereditary ring is just such that every right R-module has an L-injective cover which is monic. We also use kernels of homomorphisms to investigate L-simple L-injective covers and give some constructions ofL-simple L-iniective covers.

  15. Lung density

    DEFF Research Database (Denmark)

    Garnett, E S; Webber, C E; Coates, G

    1977-01-01

    The density of a defined volume of the human lung can be measured in vivo by a new noninvasive technique. A beam of gamma-rays is directed at the lung and, by measuring the scattered gamma-rays, lung density is calculated. The density in the lower lobe of the right lung in normal man during quiet...... breathing in the sitting position ranged from 0.25 to 0.37 g.cm-3. Subnormal values were found in patients with emphsema. In patients with pulmonary congestion and edema, lung density values ranged from 0.33 to 0.93 g.cm-3. The lung density measurement correlated well with the findings in chest radiographs...... but the lung density values were more sensitive indices. This was particularly evident in serial observations of individual patients....

  16. Passive heating of the ground surface

    Science.gov (United States)

    Tyburczyk, Anna

    2016-03-01

    The phenomenon of phase change is one of the most important contemporary issues of thermal engineering. In particular, this applies to all kinds of heat exchanger systems, which should achieve the highest possible efficiency while reducing investment and operating costs. Some of these systems are heat pipes or thermosyphons, which, among others, are used for the heat transfer, temperature stabilization and the regulation of heat flux density. Additionally, they are passive systems, and therefore do not require an external power supply. Heat pipes can be used to stabilize the surface temperature of roads and driveways. Large heat tubes can be applied for heating the surface of bridges and overpasses, which become icy in unfavorable climatic conditions. The paper presents research on the test facility, whose main component is a long vertical copper fin. The temperature at the base of the fin was kept constant for a given series of measurements. Heat receiving fluid was ethanol at atmospheric pressure. The measurement methodology and the results of investigations were discussed. The surface temperature distribution was measured with the infrared camera, and on this basis the local values of heat flow and the heat transfer coefficient were determined. The results were presented as boiling curves for both the fin with the smooth surface and the one covered with a metal capillary-porous structure. The results obtained are useful in the design of heat exchangers, including passive heating of the ground.

  17. Passive heating of the ground surface

    Directory of Open Access Journals (Sweden)

    Tyburczyk Anna

    2016-01-01

    Full Text Available The phenomenon of phase change is one of the most important contemporary issues of thermal engineering. In particular, this applies to all kinds of heat exchanger systems, which should achieve the highest possible efficiency while reducing investment and operating costs. Some of these systems are heat pipes or thermosyphons, which, among others, are used for the heat transfer, temperature stabilization and the regulation of heat flux density. Additionally, they are passive systems, and therefore do not require an external power supply. Heat pipes can be used to stabilize the surface temperature of roads and driveways. Large heat tubes can be applied for heating the surface of bridges and overpasses, which become icy in unfavorable climatic conditions. The paper presents research on the test facility, whose main component is a long vertical copper fin. The temperature at the base of the fin was kept constant for a given series of measurements. Heat receiving fluid was ethanol at atmospheric pressure. The measurement methodology and the results of investigations were discussed. The surface temperature distribution was measured with the infrared camera, and on this basis the local values of heat flow and the heat transfer coefficient were determined. The results were presented as boiling curves for both the fin with the smooth surface and the one covered with a metal capillary-porous structure. The results obtained are useful in the design of heat exchangers, including passive heating of the ground.

  18. Excitation spectra and ground-state properties from density functional theory for the inverted band-structure systems $\\beta$-HgS, HgSe, and HgTe

    CERN Document Server

    Delin, A

    2002-01-01

    We have performed a systematic density-functional study of the mercury chalcogenide compounds $\\beta$-HgS, HgSe, and HgTe using an all-electron full-potential linear muffin-tin orbital (FP-LMTO) method. We find that, in the zinc-blende structure, both HgSe and HgTe are semimetals whereas $\\beta$-HgS has a small spin-orbit induced band gap. Our calculated relativistic photoemission and inverse photoemission spectra (PES and IPES, respectively) reproduce very well the most recently measured spectra, as do also our theoretical optical spectra. In contrast to the normal situation, we find that the local density approximation (LDA) to the density functional gives calculated equilibrium volumes in much better agreement with experiment than does the generalized gradient corrected functional (GGA). We also address the problem of treating relativistic $p$ electrons with methods based on a scalar-relativistic basis set, and show that the effect is rather small for the present systems.

  19. Tree diversity and canopy cover in cocoa systems in Ghana

    DEFF Research Database (Denmark)

    Asare, Richard; Ræbild, Anders

    2016-01-01

    Cocoa (Theobroma cacao L.) growing systems in Ghana and West Africa consist of diverse tree species and densities.This study was conducted to determine factors that influence tree species configurations and how tree characteristics affect canopy cover in cocoa farms. Eighty-six farmers and corres......Cocoa (Theobroma cacao L.) growing systems in Ghana and West Africa consist of diverse tree species and densities.This study was conducted to determine factors that influence tree species configurations and how tree characteristics affect canopy cover in cocoa farms. Eighty-six farmers...... and corresponding farms were selected in a systematic approach in four districts across two agro-ecological zones in Ghana. Results show that men tend to have larger farm sizes, higher tree density and diversity than women. Tree density and canopy cover of shade trees were low on large farms, but diversity...

  20. A conceptual framework for dryland aeolian sediment transport along the grassland-forest continuum: Effects of woody plant canopy cover and disturbance

    Science.gov (United States)

    Breshears, David D.; Whicker, Jeffrey J.; Zou, Chris B.; Field, Jason P.; Allen, Craig D.

    2009-04-01

    Aeolian processes are of particular importance in dryland ecosystems where ground cover is inherently sparse because of limited precipitation. Dryland ecosystems include grassland, shrubland, savanna, woodland, and forest, and can be viewed collectively as a continuum of woody plant cover spanning from grasslands with no woody plant cover up to forests with nearly complete woody plant cover. Along this continuum, the spacing and shape of woody plants determine the spatial density of roughness elements, which directly affects aeolian sediment transport. Despite the extensiveness of dryland ecosystems, studies of aeolian sediment transport have generally focused on agricultural fields, deserts, or highly disturbed sites where rates of transport are likely to be greatest. Until recently, few measurements have been made of aeolian sediment transport over multiple wind events and across a variety of types of dryland ecosystems. To evaluate potential trends in aeolian sediment transport as a function of woody plant cover, estimates of aeolian sediment transport from recently published studies, in concert with rates from four additional locations (two grassland and two woodland sites), are reported here. The synthesis of these reports leads to the development of a new conceptual framework for aeolian sediment transport in dryland ecosystems along the grassland-forest continuum. The findings suggest that: (1) for relatively undisturbed ecosystems, shrublands have inherently greater aeolian sediment transport because of wake interference flow associated with intermediate levels of density and spacing of woody plants; and (2) for disturbed ecosystems, the upper bound for aeolian sediment transport decreases as a function of increasing amounts of woody plant cover because of the effects of the height and density of the canopy on airflow patterns and ground cover associated with woody plant cover. Consequently, aeolian sediment transport following disturbance spans the largest

  1. 14 CFR 27.1193 - Cowling and engine compartment covering.

    Science.gov (United States)

    2010-01-01

    ... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Powerplant Fire Protection... part of the cowling or engine compartment in the normal ground and flight attitudes. (c) No drain may... covering must be provided to preclude hazardous damage to rotors or critical control components in the...

  2. Multi-temporal Assessment of Forest Cover, Stocking parameters ...

    African Journals Online (AJOL)

    user

    The study assessed forest cover, stocking parameters and above-ground tree biomass dynamics in the ..... closed woodland, open woodland, bushed grassland, Marshaland, ... structure. Three VIs were tested i.e. Atmospherically Resistance. Vegetation Index .... (2008) and Vihemäki (2009) have argued that a complex.

  3. The importance of land cover change across urban-rural typologies for climate modeling.

    Science.gov (United States)

    Vargo, Jason; Habeeb, Dana; Stone, Brian

    2013-01-15

    Land cover changes affect local surface energy balances by changing the amount of solar energy reflected, the magnitude and duration over which absorbed energy is released as heat, and the amount of energy that is diverted to non-heating fluxes through evaporation. However, such local influences often are only crudely included in climate modeling exercises, if at all. A better understanding of local land conversion dynamics can serve to inform inputs for climate models and increase the role for land use planning in climate management policy. Here we present a new approach for projecting and incorporating metropolitan land cover change into mesoscale climate and other environmental assessment models. Our results demonstrate the relative contributions of different land development patterns to land cover change and conversion and suggest that regional growth management strategies serving to increase settlement densities over time can have a significant influence on the rate of deforestation per unit of population growth. Employing the approach presented herein, the impacts of land conversion on climate change and on parallel environmental systems and services, such as ground water recharge, habitat provision, and food production, may all be investigated more closely and managed through land use planning. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Land Cover Classification Using ALOS Imagery For Penang, Malaysia

    Science.gov (United States)

    Sim, C. K.; Abdullah, K.; MatJafri, M. Z.; Lim, H. S.

    2014-02-01

    This paper presents the potential of integrating optical and radar remote sensing data to improve automatic land cover mapping. The analysis involved standard image processing, and consists of spectral signature extraction and application of a statistical decision rule to identify land cover categories. A maximum likelihood classifier is utilized to determine different land cover categories. Ground reference data from sites throughout the study area are collected for training and validation. The land cover information was extracted from the digital data using PCI Geomatica 10.3.2 software package. The variations in classification accuracy due to a number of radar imaging processing techniques are studied. The relationship between the processing window and the land classification is also investigated. The classification accuracies from the optical and radar feature combinations are studied. Our research finds that fusion of radar and optical significantly improved classification accuracies. This study indicates that the land cover/use can be mapped accurately by using this approach.

  5. Ground state energy of dilute neutron matter at next-to-leading order in lattice chiral effective field theory

    CERN Document Server

    Epelbaum, Evgeny; Lee, Dean; Meißner, Ulf-G

    2008-01-01

    We present lattice calculations for the ground state energy of dilute neutron matter at next-to-leading order in chiral effective field theory. This study follows a series of recent papers on low-energy nuclear physics using chiral effective field theory on the lattice. In this work we introduce an improved spin- and isospin-projected leading-order action which allows for a perturbative treatment of corrections at next-to-leading order and smaller estimated errors. Using auxiliary fields and Euclidean-time projection Monte Carlo, we compute the ground state of 8, 12, and 16 neutrons in a periodic cube, covering a density range from 2% to 10% of normal nuclear density.

  6. Modeled ground water age distributions

    Science.gov (United States)

    Woolfenden, Linda R.; Ginn, Timothy R.

    2009-01-01

    The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

  7. Replacing fallow by cover crops: economic sustainability

    Science.gov (United States)

    Gabriel, José Luis; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Replacing fallow by cover crops in intensive fertilized systems has been demonstrated as an efficient tool for reducing nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of this new technology is still limited because they are either unwilling or unable, although adoption reluctance is frequently rooted in low economic profitability, low water se efficiency or poor knowledge. Economic analyses permit a comparison between the profit that farmers obtain from agricultural products and the cost of adopting specific agricultural techniques. The goal of this study was to evaluate the economic impact of replacing the usual winter fallow with cover crops (barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo)) in irrigated maize systems and variable Mediterranean weather conditions using stochastic Monte-Carlo simulations of key farms' financial performance indicators. The three scenarios studied for each cover crop were: i) just leaving the cover crop residue in the ground, ii) leaving the cover crop residue but reduce following maize fertilization according to the N available from the previous cover crop and iii) selling the cover crop residue for animal feeding. All the scenarios were compared with respect to a typical maize-fallow rotation. With observed data from six different years and in various field trials, looking for different weather conditions, probability distribution functions of maize yield, cover crop biomass production and N fertilizer saving was fitted. Based in statistical sources maize grain price, different forage prices and the cost of fertilizer were fitted to probability distribution functions too. As result, introducing a cover crop involved extra costs with respect to fallow as the initial investment, because new seed, herbicide or extra field operations. Additional

  8. Engineered soil covers for management of salt impacted sites

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, D.A. [SEACOR Environmental Inc., Vancouver, BC (Canada); Tratch, D.J. [Watermark Consulting Ltd., Regina, SK (Canada)

    2005-07-01

    The use of engineered soil cover systems to mitigate environmental impacts from tailings and waste rock piles is becoming an accepted practice. This paper presented design concepts for soil covers related to reclamation practices in the mining industry as an effective risk management practice at salt impacted sites. Research and field programs have demonstrated that a layered engineered soil cover can reduce or eliminate infiltration. Key components of the system included re-establishing surface vegetation to balance precipitation fluxes with evapotranspiration potential, and design of a capillary break below the rooting zone to minimize deeper seated infiltration. It was anticipated that the incorporation of a vegetation cover and a capillary break would minimize infiltration into the waste rock or tailing pile and reduce the generation of acid rock drainage (ARD). Design of a layered soil cover requires the incorporation of meteorological data, moisture retention characteristics of the impacted soils, and proposed engineered cover materials. Performance of the soil cover was predicted using a finite element model combined with meteorological data from the site area, unsaturated soil properties of the parent sub-surface soils and potential covered materials. The soil cover design consisted of re-vegetation and a loose clay cover overlying a compacted till layer. The design was conducted for an off site release of salt impacted pasture land adjacent to a former highway maintenance yard. The model predicted minimal infiltration during high precipitation events and no infiltration during low precipitation events. Results indicated that the proposed soil cover would enable re-establishment of a productive agricultural ground cover, as well as minimizing the potential for additional salt migration. It was concluded that further research and development is needed to ensure that the cover system is an acceptable method for long-term risk management. 17 refs., 5 figs.

  9. Estimating pinyon and juniper cover across Utah using NAIP imagery

    Directory of Open Access Journals (Sweden)

    Darrell B. Roundy

    2016-11-01

    Full Text Available Expansion of Pinus L. (pinyon and Juniperus L. (juniper (P-J trees into sagebrush (Artemisia L. steppe communities can lead to negative effects on hydrology, loss of wildlife habitat, and a decrease in desirable understory vegetation. Tree reduction treatments are often implemented to mitigate these negative effects. In order to prioritize and effectively plan these treatments, rapid, accurate, and inexpensive methods are needed to estimate tree canopy cover at the landscape scale. We used object based image analysis (OBIA software (Feature AnalystTM for ArcMap 10.1®, ENVI Feature Extraction®, and Trimble eCognition Developer 8.2® to extract tree canopy cover using NAIP (National Agricultural Imagery Program imagery. We then compared our extractions with ground measured tree canopy cover (crown diameter and line point intercept on 309 plots across 44 sites in Utah. Extraction methods did not consistently over- or under-estimate ground measured P-J canopy cover except where tree cover was >45%. Estimates of tree canopy cover using OBIA techniques were strongly correlated with estimates using the crown diameter method (r = 0.93 for ENVI, 0.91 for Feature AnalystTM, and 0.92 for eCognition. Tree cover estimates using OBIA techniques had lower correlations with tree cover measurements using the line-point intercept method (r = 0.85 for ENVI, 0.83 for Feature AnalystTM, and 0.83 for eCognition. All software packages accurately and inexpensively extracted P-J canopy cover from NAIP imagery when the imagery was not blurred, and when P-J cover was not mixed with Amelanchier alnifolia (Utah serviceberry and Quercus gambelii (Gambel’s oak, which had similar spectral values as P-J.

  10. Gedanken Densities and Exact Constraints in Density Functional Theory

    CERN Document Server

    Perdew, John P; Sun, Jianwei; Burke, Kieron

    2014-01-01

    Approximations to the exact density functional for the exchange-correlation energy of a many-electron ground state can be constructed by satisfying constraints that are universal, i.e., valid for all electron densities. Gedanken densities are designed for the purpose of this construction, but need not be realistic. The uniform electron gas is an old gedanken density. Here, we propose a spherical two-electron gedanken density in which the dimensionless density gradient can be an arbitrary positive constant wherever the density is non-zero. The Lieb-Oxford lower bound on the exchange energy can be satisfied within a generalized gradient approximation (GGA) by bounding its enhancement factor or simplest GGA exchange-energy density. This enhancement-factor bound is well known to be sufficient, but our gedanken density shows that it is also necessary. The conventional exact exchange-energy density satisfies no such local bound, but energy densities are not unique, and the simplest GGA exchange-energy density is no...

  11. Hanford site ground water protection management plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    Ground water protection at the Hanford Site consists of preventative and remedial measures that are implemented in compliance with a variety of environmental regulations at local, state, and federal levels. These measures seek to ensure that the resource can sustain a broad range of beneficial uses. To effectively coordinate and ensure compliance with applicable regulations, the U.S. Department of Energy has issued DOE Order 5400.1 (DOE 1988a). This order requires all U.S. Department of Energy facilities to prepare separate ground water protection program descriptions and plans. This document describes the Ground Water Protection Management Plan (GPMP) for the Hanford Site located in the state of Washington. DOE Order 5400.1 specifies that the GPMP covers the following general topical areas: (1) documentation of the ground water regime; (2) design and implementation of a ground water monitoring program to support resource management and comply with applicable laws and regulations; (3) a management program for ground water protection and remediation; (4) a summary and identification of areas that may be contaminated with hazardous waste; (5) strategies for controlling hazardous waste sources; (6) a remedial action program; and (7) decontamination, decommissioning, and related remedial action requirements. Many of the above elements are currently covered by existing programs at the Hanford Site; thus, one of the primary purposes of this document is to provide a framework for coordination of existing ground water protection activities. The GPMP provides the ground water protection policy and strategies for ground water protection/management at the Hanford Site, as well as an implementation plan to improve coordination of site ground water activities.

  12. Set Covering Problems with General Objective Functions

    CERN Document Server

    Cardinal, Jean

    2008-01-01

    We introduce a parameterized version of set cover that generalizes several previously studied problems. Given a ground set V and a collection of subsets S_i of V, a feasible solution is a partition of V such that each subset of the partition is included in one of the S_i. The problem involves maximizing the mean subset size of the partition, where the mean is the generalized mean of parameter p, taken over the elements. For p=-1, the problem is equivalent to the classical minimum set cover problem. For p=0, it is equivalent to the minimum entropy set cover problem, introduced by Halperin and Karp. For p=1, the problem includes the maximum-edge clique partition problem as a special case. We prove that the greedy algorithm simultaneously approximates the problem within a factor of (p+1)^1/p for any p in R^+, and that this is the best possible unless P=NP. These results both generalize and simplify previous results for special cases. We also consider the corresponding graph coloring problem, and prove several tr...

  13. Combinatorial aspects of covering arrays

    Directory of Open Access Journals (Sweden)

    Charles J. Colbourn

    2004-11-01

    Full Text Available Covering arrays generalize orthogonal arrays by requiring that t -tuples be covered, but not requiring that the appearance of t -tuples be balanced.Their uses in screening experiments has found application in software testing, hardware testing, and a variety of fields in which interactions among factors are to be identified. Here a combinatorial view of covering arrays is adopted, encompassing basic bounds, direct constructions, recursive constructions, algorithmic methods, and applications.

  14. A High Performance Computing Approach to Tree Cover Delineation in 1-m NAIP Imagery Using a Probabilistic Learning Framework

    Science.gov (United States)

    Basu, Saikat; Ganguly, Sangram; Michaelis, Andrew; Votava, Petr; Roy, Anshuman; Mukhopadhyay, Supratik; Nemani, Ramakrishna

    2015-01-01

    Tree cover delineation is a useful instrument in deriving Above Ground Biomass (AGB) density estimates from Very High Resolution (VHR) airborne imagery data. Numerous algorithms have been designed to address this problem, but most of them do not scale to these datasets, which are of the order of terabytes. In this paper, we present a semi-automated probabilistic framework for the segmentation and classification of 1-m National Agriculture Imagery Program (NAIP) for tree-cover delineation for the whole of Continental United States, using a High Performance Computing Architecture. Classification is performed using a multi-layer Feedforward Backpropagation Neural Network and segmentation is performed using a Statistical Region Merging algorithm. The results from the classification and segmentation algorithms are then consolidated into a structured prediction framework using a discriminative undirected probabilistic graphical model based on Conditional Random Field, which helps in capturing the higher order contextual dependencies between neighboring pixels. Once the final probability maps are generated, the framework is updated and re-trained by relabeling misclassified image patches. This leads to a significant improvement in the true positive rates and reduction in false positive rates. The tree cover maps were generated for the whole state of California, spanning a total of 11,095 NAIP tiles covering a total geographical area of 163,696 sq. miles. The framework produced true positive rates of around 88% for fragmented forests and 74% for urban tree cover areas, with false positive rates lower than 2% for both landscapes. Comparative studies with the National Land Cover Data (NLCD) algorithm and the LiDAR canopy height model (CHM) showed the effectiveness of our framework for generating accurate high-resolution tree-cover maps.

  15. A High Performance Computing Approach to Tree Cover Delineation in 1-m NAIP Imagery using a Probabilistic Learning Framework

    Science.gov (United States)

    Basu, S.; Ganguly, S.; Michaelis, A.; Votava, P.; Roy, A.; Mukhopadhyay, S.; Nemani, R. R.

    2015-12-01

    Tree cover delineation is a useful instrument in deriving Above Ground Biomass (AGB) density estimates from Very High Resolution (VHR) airborne imagery data. Numerous algorithms have been designed to address this problem, but most of them do not scale to these datasets which are of the order of terabytes. In this paper, we present a semi-automated probabilistic framework for the segmentation and classification of 1-m National Agriculture Imagery Program (NAIP) for tree-cover delineation for the whole of Continental United States, using a High Performance Computing Architecture. Classification is performed using a multi-layer Feedforward Backpropagation Neural Network and segmentation is performed using a Statistical Region Merging algorithm. The results from the classification and segmentation algorithms are then consolidated into a structured prediction framework using a discriminative undirected probabilistic graphical model based on Conditional Random Field, which helps in capturing the higher order contextual dependencies between neighboring pixels. Once the final probability maps are generated, the framework is updated and re-trained by relabeling misclassified image patches. This leads to a significant improvement in the true positive rates and reduction in false positive rates. The tree cover maps were generated for the whole state of California, spanning a total of 11,095 NAIP tiles covering a total geographical area of 163,696 sq. miles. The framework produced true positive rates of around 88% for fragmented forests and 74% for urban tree cover areas, with false positive rates lower than 2% for both landscapes. Comparative studies with the National Land Cover Data (NLCD) algorithm and the LiDAR canopy height model (CHM) showed the effectiveness of our framework for generating accurate high-resolution tree-cover maps.

  16. Ground water and energy

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This national workshop on ground water and energy was conceived by the US Department of Energy's Office of Environmental Assessments. Generally, OEA needed to know what data are available on ground water, what information is still needed, and how DOE can best utilize what has already been learned. The workshop focussed on three areas: (1) ground water supply; (2) conflicts and barriers to ground water use; and (3) alternatives or solutions to the various issues relating to ground water. (ACR)

  17. You can hide but you can't run: apparent competition, predator responses and the decline of Arctic ground squirrels in boreal forests of the southwest Yukon.

    Science.gov (United States)

    Werner, Jeffery R; Gillis, Elizabeth A; Boonstra, Rudy; Krebs, Charles J

    2016-01-01

    Throughout much of North America's boreal forest, the cyclical fluctuations of snowshoe hare populations (Lepus americanus) may cause other herbivores to become entrained in similar cycles. Alternating apparent competition via prey switching followed by positive indirect effects are the mechanisms behind this interaction. Our purpose is to document a change in the role of indirect interactions between sympatric populations of hares and arctic ground squirrels (Urocitellus parryii plesius), and to emphasize the influence of predation for controlling ground squirrel numbers. We used mark-recapture to estimate the population densities of both species over a 25-year period that covered two snowshoe hare cycles. We analysed the strength of association between snowshoe hare and ground squirrel numbers, and the changes to the seasonal and annual population growth rates of ground squirrels over time. A hyperbolic curve best describes the per capita rate of increase of ground squirrels relative to their population size, with a single stable equilibrium and a lower critical threshold below which populations drift to extinction. The crossing of this unstable boundary resulted in the subsequent uncoupling of ground squirrel and hare populations following the decline phase of their cycles in 1998. The implications are that this sustained Type II predator response led to the local extinction of ground squirrels. When few individuals are left in a colony, arctic ground squirrels may also have exhibited an Allee effect caused by the disruption of social signalling of approaching predators.

  18. You can hide but you can’t run: apparent competition, predator responses and the decline of Arctic ground squirrels in boreal forests of the southwest Yukon

    Science.gov (United States)

    Gillis, Elizabeth A.; Boonstra, Rudy; Krebs, Charles J.

    2016-01-01

    Throughout much of North America’s boreal forest, the cyclical fluctuations of snowshoe hare populations (Lepus americanus) may cause other herbivores to become entrained in similar cycles. Alternating apparent competition via prey switching followed by positive indirect effects are the mechanisms behind this interaction. Our purpose is to document a change in the role of indirect interactions between sympatric populations of hares and arctic ground squirrels (Urocitellus parryii plesius), and to emphasize the influence of predation for controlling ground squirrel numbers. We used mark-recapture to estimate the population densities of both species over a 25-year period that covered two snowshoe hare cycles. We analysed the strength of association between snowshoe hare and ground squirrel numbers, and the changes to the seasonal and annual population growth rates of ground squirrels over time. A hyperbolic curve best describes the per capita rate of increase of ground squirrels relative to their population size, with a single stable equilibrium and a lower critical threshold below which populations drift to extinction. The crossing of this unstable boundary resulted in the subsequent uncoupling of ground squirrel and hare populations following the decline phase of their cycles in 1998. The implications are that this sustained Type II predator response led to the local extinction of ground squirrels. When few individuals are left in a colony, arctic ground squirrels may also have exhibited an Allee effect caused by the disruption of social signalling of approaching predators. PMID:27635312

  19. You can hide but you can’t run: apparent competition, predator responses and the decline of Arctic ground squirrels in boreal forests of the southwest Yukon

    Directory of Open Access Journals (Sweden)

    Jeffery R. Werner

    2016-08-01

    Full Text Available Throughout much of North America’s boreal forest, the cyclical fluctuations of snowshoe hare populations (Lepus americanus may cause other herbivores to become entrained in similar cycles. Alternating apparent competition via prey switching followed by positive indirect effects are the mechanisms behind this interaction. Our purpose is to document a change in the role of indirect interactions between sympatric populations of hares and arctic ground squirrels (Urocitellus parryii plesius, and to emphasize the influence of predation for controlling ground squirrel numbers. We used mark-recapture to estimate the population densities of both species over a 25-year period that covered two snowshoe hare cycles. We analysed the strength of association between snowshoe hare and ground squirrel numbers, and the changes to the seasonal and annual population growth rates of ground squirrels over time. A hyperbolic curve best describes the per capita rate of increase of ground squirrels relative to their population size, with a single stable equilibrium and a lower critical threshold below which populations drift to extinction. The crossing of this unstable boundary resulted in the subsequent uncoupling of ground squirrel and hare populations following the decline phase of their cycles in 1998. The implications are that this sustained Type II predator response led to the local extinction of ground squirrels. When few individuals are left in a colony, arctic ground squirrels may also have exhibited an Allee effect caused by the disruption of social signalling of approaching predators.

  20. Influence of cover crop and intercrop systems on Bemisia argentifolli (Hemiptera: Aleyrodidae) infestation and associated squash silverleaf disorder in zucchini.

    Science.gov (United States)

    Manandhar, Roshan; Hooks, Cerruti R R; Wright, Mark G

    2009-04-01

    Field experiments were conducted to evaluate the effects of cover cropping and intercropping on population densities of silverleaf whitefly, Bemisia argentifolli Bellow and Perring, and the incidence of squash silverleaf disorder (SSL) in zucchini, Cucurbita pepo L., in Oahu, HI. Two cover crops, buckwheat (BW), Fagopyrum esculentum Moench, and white clover (WC), Trifolium repens L., or sunn hemp (SH), Crotolaria juncea L., and an intercropped vegetable, okra, Abelmonchus esculentus L., were evaluated during the 2003, 2005, and 2006 growing seasons, respectively. Population densities of whiteflies and SSL severity varied during the three field experiments. In 2003, the severity of SSL and percentage of leaves displaying symptoms were significantly lower on zucchini plants in WC than BW plots throughout the crops' growth cycle. Additionally, the percentage of leaves per plant displaying SSL symptoms was significantly greater in bare-ground (BG) compared with the pooled BW and WC treatments on each inspection date. In 2005, zucchini intercropped with okra had lower numbers of adult whiteflies and resulted in significantly lower severity of SSL than pooled BW and WC treatments. During 2006, zucchini grown with SH had significantly lower numbers of all whitefly stages (i.e., egg, immature, and adult) and less SSL severity symptoms than BW. Despite these differences in whitefly numbers and SSL severity, marketable yields were not significantly lower in BW compared with WC or SH treatment plots during the study. The mechanisms underlying these results and the feasibility of using cover crops and intercrops to manage B. argentifolli and SSL are discussed.

  1. Effects of Conservation Policies on Forest Cover Change in Giant Panda Habitat Regions, China.

    Science.gov (United States)

    Li, Yu; Viña, Andrés; Yang, Wu; Chen, Xiaodong; Zhang, Jindong; Ouyang, Zhiyun; Liang, Zai; Liu, Jianguo

    2013-07-01

    After long periods of deforestation, forest transition has occurred globally, but the causes of forest transition in different countries are highly variable. Conservation policies may play important roles in facilitating forest transition around the world, including China. To restore forests and protect the remaining natural forests, the Chinese government initiated two nationwide conservation policies in the late 1990s -- the Natural Forest Conservation Program (NFCP) and the Grain-To-Green Program (GTGP). While some studies have discussed the environmental and socioeconomic effects of each of these policies independently and others have attributed forest recovery to both policies without rigorous and quantitative analysis, it is necessary to rigorously quantify the outcomes of these two conservation policies simultaneously because the two policies have been implemented at the same time. To fill the knowledge gap, this study quantitatively evaluated the effects of the two conservation policies on forest cover change between 2001 and 2008 in 108 townships located in two important giant panda habitat regions -- the Qinling Mountains region in Shaanxi Province and the Sichuan Giant Panda Sanctuary in Sichuan Province. Forest cover change was evaluated using a land-cover product (MCD12Q1) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). This product proved to be highly accurate in the study region (overall accuracy was ca. 87%, using 425 ground truth points collected in the field), thus suitable for the forest change analysis performed. Results showed that within the timeframe evaluated, most townships in both regions exhibited either increases or no changes in forest cover. After accounting for a variety of socioeconomic and biophysical attributes, an Ordinary Least Square (OLS) regression model suggests that the two policies had statistically significant positive effects on forest cover change after seven years of implementation, while

  2. Dualities in Covering Rough Operations

    Institute of Scientific and Technical Information of China (English)

    William Zhu

    2006-01-01

    Rough set theory is a technique of granular computing. In this paper, we study a type of generalized rough sets based on covering. There are several literatures[ 1,40-43 ] exploring covering-based rough sets. Our focus of this paper is on the dualities in rough operations.

  3. High plains cover crop research

    Science.gov (United States)

    Some recent statements have been made about the benefits of growing cover crops in mixtures as compared with single-species plantings of cover crops. Those stated benefits have included greatly reduced water use, enhanced soil microbiological activity, increased biomass productivity, and enhanced wa...

  4. Midwest Cover Crops Field Guide

    Science.gov (United States)

    Producers who want to prevent soil erosion, improve nutrient cycling, sustain their soils, and protect/maintain the environment have been returning to a very old practice: planting cover crops. Cover crops are effective tools for reducing soil erosion and increasing nutrient recycling on farmlands, ...

  5. Development of large Area Covering Height Model

    Science.gov (United States)

    Jacobsen, K.

    2014-04-01

    Height information is a basic part of topographic mapping. Only in special areas frequent update of height models is required, usually the update cycle is quite lower as for horizontal map information. Some height models are available free of charge in the internet; for commercial height models a fee has to be paid. Mostly digital surface models (DSM) with the height of the visible surface are given and not the bare ground height, as required for standard mapping. Nevertheless by filtering of DSM, digital terrain models (DTM) with the height of the bare ground can be generated with the exception of dense forest areas where no height of the bare ground is available. These height models may be better as the DTM of some survey administrations. In addition several DTM from national survey administrations are classified, so as alternative the commercial or free of charge available information from internet can be used. The widely used SRTM DSM is available also as ACE-2 GDEM corrected by altimeter data for systematic height errors caused by vegetation and orientation errors. But the ACE-2 GDEM did not respect neighbourhood information. With the worldwide covering TanDEM-X height model, distributed starting 2014 by Airbus Defence and Space (former ASTRIUM) as WorldDEM, higher level of details and accuracy is reached as with other large area covering height models. At first the raw-version of WorldDEM will be available, followed by an edited version and finally as WorldDEM-DTM a height model of the bare ground. With 12 m spacing and a relative standard deviation of 1.2 m within an area of 1° x 1° an accuracy and resolution level is reached, satisfying also for larger map scales. For limited areas with the HDEM also a height model with 6 m spacing and a relative vertical accuracy of 0.5 m can be generated on demand. By bathymetric LiDAR and stereo images also the height of the sea floor can be determined if the water has satisfying transparency. Another method of getting

  6. Automatic design of magazine covers

    Science.gov (United States)

    Jahanian, Ali; Liu, Jerry; Tretter, Daniel R.; Lin, Qian; Damera-Venkata, Niranjan; O'Brien-Strain, Eamonn; Lee, Seungyon; Fan, Jian; Allebach, Jan P.

    2012-03-01

    In this paper, we propose a system for automatic design of magazine covers that quantifies a number of concepts from art and aesthetics. Our solution to automatic design of this type of media has been shaped by input from professional designers, magazine art directors and editorial boards, and journalists. Consequently, a number of principles in design and rules in designing magazine covers are delineated. Several techniques are derived and employed in order to quantify and implement these principles and rules in the format of a software framework. At this stage, our framework divides the task of design into three main modules: layout of magazine cover elements, choice of color for masthead and cover lines, and typography of cover lines. Feedback from professional designers on our designs suggests that our results are congruent with their intuition.

  7. Absence of snow cover reduces understory plant cover and alters plant community composition in boreal forests.

    Science.gov (United States)

    Kreyling, Juergen; Haei, Mahsa; Laudon, Hjalmar

    2012-02-01

    Snow regimes affect biogeochemistry of boreal ecosystems and are altered by climate change. The effects on plant communities, however, are largely unexplored despite their influence on relevant processes. Here, the impact of snow cover on understory community composition and below-ground production in a boreal Picea abies forest was investigated using a long-term (8-year) snow cover manipulation experiment consisting of the treatments: snow removal, increased insulation (styrofoam pellets), and control. The snow removal treatment caused longer (118 vs. 57 days) and deeper soil frost (mean minimum temperature -5.5 vs. -2.2°C) at 10 cm soil depth in comparison to control. Understory species composition was strongly altered by the snow cover manipulations; vegetation cover declined by more than 50% in the snow removal treatment. In particular, the dominant dwarf shrub Vaccinium myrtillus (-82%) and the most abundant mosses Pleurozium schreberi (-74%) and Dicranum scoparium (-60%) declined strongly. The C:N ratio in V. myrtillus leaves and plant available N in the soil indicated no altered nitrogen nutrition. Fine-root biomass in summer, however, was negatively affected by the reduced snow cover (-50%). Observed effects are attributed to direct frost damage of roots and/ or shoots. Besides the obvious relevance of winter processes on plant ecology and distribution, we propose that shifts in the vegetation caused by frost damage may be an important driver of the reported alterations in biogeochemistry in response to altered snow cover. Understory plant performance clearly needs to be considered in the biogeochemistry of boreal systems in the face of climate change.

  8. The use of cover crops to control tree invasion on a right-of-way near Tobermory Illinois: Crop establishment and tree invasion following the second growing season

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.

    1991-02-20

    In the past two decades Ontario Hydro has relied on selective herbicide applications to remove compatible trees from its transmission and distribution rights-of-way. This approach was designed to encourage a type of biological control, where the compatible ground cover slows the invasion of tree species via competitive interaction. The success is dependent upon the occurrence of species in the area which are able to successfully interfere with tree establishment and/or growth. An alternative method of establishing this control is by replacing the existing vegetation with species that have a demonstrated ability to interfere with tree establishment. A distribution line in the Tobermory area of the Bruce Peninsula became available for an experimental cover crop planting. The line was cleared of incompatible species during the winter of 1988. A random block experimental design was used to test 6 treatments at 6 sites along this right-of-way. The treatments consisted of soil scarification and seeding with Festuca rubra, Lotus corniculatus, Dactylis glomerata, Coronilla varia and Lotium multiflorum; soil scarification and no seeding; and no soil scarification and no seeding. At the end of the 1990 growing season, the crops were established in their respective plots with good frequencies (ranging from 20 to 100%). F. rubra and D. glomerata had a mean cover of 25% and could be considered as the dominant ground cover in their treatment plots. C. varia and L. corniculatus had relatively low covers of 5 and 2%. Incompatible trees were found at the study area, with densities varying at each site. Densities were not statistically affected by the treatment, but had not increased from last year. 32 refs., 11 figs., 5 tabs.

  9. Cover of tall trees best predicts California spotted owl habitat

    Science.gov (United States)

    Malcolm P. North; Jonathan T. Kane; Van R. Kane; Gregory P. Asner; William Berigan; Derek J. Churchill; Scott Conway; R.J. Gutiérrez; Sean Jeronimo; John Keane; Alexander Koltunov; Tina Mark; Monika Moskal; Thomas Munton; Zachary Peery; Carlos Ramirez; Rahel Sollmann; Angela White; Sheila Whitmore

    2017-01-01

    Restoration of western dry forests in the USA often focuses on reducing fuel loads. In the range of the spotted owl, these treatments may reduce canopy cover and tree density, which could reduce preferred habitat conditions for the owl and other sensitive species. In particular, high canopy cover (≥70%) has been widely reported to be an important feature of spotted owl...

  10. Decreasing seagrass density negatively influences associated fauna.

    Science.gov (United States)

    McCloskey, Rosemary M; Unsworth, Richard K F

    2015-01-01

    Seagrass meadows globally are disappearing at a rapid rate with physical disturbances being one of the major drivers of this habitat loss. Disturbance of seagrass can lead to fragmentation, a reduction in shoot density, canopy height and coverage, and potentially permanent loss of habitat. Despite being such a widespread issue, knowledge of how such small scale change affects the spatial distribution and abundances of motile fauna remains limited. The present study investigated fish and macro faunal community response patterns to a range of habitat variables (shoot length, cover and density), including individual species habitat preferences within a disturbed and patchy intertidal seagrass meadow. Multivariate analysis showed a measurable effect of variable seagrass cover on the abundance and distribution of the fauna, with species specific preferences to both high and low seagrass cover seagrass. The faunal community composition varied significantly with increasing/decreasing cover. The faunal species composition of low cover seagrass was more similar to sandy control plots than to higher cover seagrass. Shannon Wiener Diversity (H') and species richness was significantly higher in high cover seagrass than in low cover seagrass, indicating increasing habitat value as density increases. The results of this study underline how the impacts of small scale disturbances from factors such as anchor damage, boat moorings and intertidal vehicle use on seagrass meadows that reduce shoot density and cover can impact upon associated fauna. These impacts have negative consequences for the delivery of ecosystem services such as the provision of nursery habitat.

  11. EDGE COVERING COLORING AND FRACTIONAL EDGE COVERING COLORING

    Institute of Scientific and Technical Information of China (English)

    MIAOLianying; LIUGuizhen

    2002-01-01

    Let G be a graph with edge set E(G).S E(G)is called an edge cover of G if every vertex of G is an end vertex of some edges in S.The edge covering chromatic number of a graph G,denoted by Xc(G),is the maximum size of a partition of E(G) into edge covers of G.It is known that for any graph G with minimum degree δ,δ-1≤Xc(G)≤δ.The fractional edge covering chromatic number of a graph G,denoted by Xcf(G),is the fractional matiching number of the edge covering hypergraph H of G whose vertices are the edges of G and whose hypereges the edge covers of G.In this paper,we study the relation between Xc(G) and δfor any graph G,and give a new simple proof of the inequalities δ-1≤Xc(G)≤δ by the technique of graph coloring.For any graph G,we give an exact formula o Xcf(G),that is,Xcf(G)=min{δ,λ(G)},where λ(G)=minCS/S/2 and the minimum is taken over all noempty subsets S of V(G) and C[S] is the set of edges that have at least one end in S.δ

  12. EDGE COVERING COLORING AND FRACTIONAL EDGE COVERING COLORING

    Institute of Scientific and Technical Information of China (English)

    MIAO Lianying; LIU Guizhen

    2002-01-01

    Let G be a graph with edge set E(G). S _C E(G) is called an edge cover of G if every vertex of G is an end vertex of some edges in S. The edge covering chromatic number of a graph G, denoted by X'c(G) , is the maximum size of a partition of E(G) into edge covers of G. It is known that for any graph G with minimum degree δ, δ - 1 ≤ X'c(G) ≤ δ.The fractional edge covering chromatic number of a graph G, denoted by X'cf(G), is the fractional matching number of the edge covering hypergraph H of G whose vertices are the edges of G and whose hyperedges the edge covers of G. In this paper, we study the relation between X'c(G) and δ for any graph G, and give a new simple proof of the inequalities δ - 1 ≤ X'c(G) ≤ δ by the technique of graph coloring. For any graph G, we give an exact formula of X'cf(G), that is, X'cf(G)=min{δ,λ(G)}, where λ(G)=min |C[S]|/[|S|/2]and the minimum is taken over all noempty subsets S of V(G) and C[S] is the set of edges that have at least one end in S.

  13. Book Review: Grounded Theory: A practical guide (Birks & Mills, 2011

    Directory of Open Access Journals (Sweden)

    Astrid Gynnild, Ph.D.

    2011-12-01

    Full Text Available What is grounded theory and how is a grounded theory study carried out? Several recent publications have been trying to answer these questions, building on a literature list on the topic that covers more than 40 years of research and scholarship. According to the authors, this book is aimed at beginner researchers, research students and experienced researchers from a variety of disciplines who are unfamiliar with grounded theory.

  14. Book Review: Grounded Theory: A practical guide (Birks & Mills, 2011)

    OpenAIRE

    Astrid Gynnild, Ph.D.

    2011-01-01

    What is grounded theory and how is a grounded theory study carried out? Several recent publications have been trying to answer these questions, building on a literature list on the topic that covers more than 40 years of research and scholarship. According to the authors, this book is aimed at beginner researchers, research students and experienced researchers from a variety of disciplines who are unfamiliar with grounded theory.

  15. Calculation of excitation energies of open-shell molecules with spatially degenerate ground states. I. Transformed reference via an intermediate configuration Kohn-Sham density-functional theory and applications to d1 and d2 systems with octahedral and tetrahedral symmetries.

    Science.gov (United States)

    Seth, Michael; Ziegler, Tom

    2005-10-08

    A method for calculating the UV-vis spectra of molecules with spatially degenerate ground states using time-dependent density-functional theory (TDDFT) is proposed. The new transformed reference via an intermediate configuration Kohn-Sham TDDFT (TRICKS-TDDFT) method avoids the difficulties caused by the multireference nature of spatially degenerate states by rather than utilizing the ground state instead taking a nondegenerate excited state with desirable properties as the reference for the TDDFT calculation. The scope and practical application of the method are discussed. Like all open-shell TDDFT calculations this method at times suffers from the inability to produce transitions to states that are eigenfunctions of the total spin operator. A technique for alleviating this difficulty to some extent is proposed. The applicability and accuracy of the TRICKS-TDDFT method is demonstrated through example calculations of several d(1) and d(2) transition metal complexes with tetrahedral and octahedral symmetries. For the most part, the results of these calculations are similar in quality to to those obtained from standard TDDFT calculations.

  16. Determining Covers in Combinational Circuits

    Directory of Open Access Journals (Sweden)

    Ljubomir Cvetkovic

    2011-05-01

    Full Text Available In this paper we propose a procedure for determining 0- or 1-cover of an arbitrary line in a combinational circuit. When determining a cover we do not need Boolean expression for the line; only the circuit structure is used. Within the proposed procedure we use the tools of the cube theory, in particular, some operations defined on cubes. The procedure can be applied for determining 0- and 1- covers of output lines in programmable logic devices. Basically, this procedure is a method for the analysis of a combinational circuit.

  17. The effect of vegetation cover on the formation of glide-snow avalanches

    Science.gov (United States)

    Feistl, Thomas; Bebi, Peter; Bartelt, Perry

    2014-05-01

    Glide snow avalanches release on steep, smooth slopes and can be prevented either by protection forests or by artificial defense structures. To minimize the risk for people and infrastructure, guidelines have been formulated concerning structure, height and distance between avalanche prevention bridges. These guidelines assure the major functions of the defense structures: first to prevent the release of avalanches and second to withstand the static and dynamic forces of the moving snow cover. The major functions of protection forests are generally similar and therefore guidelines on the maximum tolerable size of forest gaps exist in Switzerland. These guidelines are based on a static relationship between the pressure of the snow cover and the resistance of the defense structure and on empirical observations (forest). Whereas ground friction is only qualitatively taken into account, we assume it to play a crucial role in glide snow avalanche formation. To prove this assumption we collected data on the predominant vegetation cover of 67 release areas in the region of Davos, Switzerland. Our observations reveal a strong relationship between vegetation cover type, slope angle and slab length. We were able to quantify the Coulomb friction parameter μ by applying a physical model that accounts for the dynamic forces of the moving snow on the stauchwall, the fixed snow cover below the release area. The stauchwall resists the dynamic forces of the snow cover, until a critical strain rate is reached and then fails in brittle compression. This failure strongly depends on the friction between snow cover and soil. A typical value of μ for grassy slopes is 0.2. Snow characteristics like density are implemented in the model as constants. We compared the model results with the guidelines for defense structures and forest gap sizes and found accordance for certain friction parameter values. Forest gaps of 40 meter length and a 35° slope angle require friction values of 0

  18. Ground Control for Emplacement Drifts for LA

    Energy Technology Data Exchange (ETDEWEB)

    Y. Sun

    2004-07-09

    The purpose of this calculation is to analyze the stability of repository emplacement drifts during the preclosure period, and to provide a final ground support method for emplacement drifts for the License Application (LA). The scope of the work includes determination of input parameter values and loads, selection of appropriate process and methods for the calculation, application of selected methods, such as empirical or analytical, to the calculation, development and execution of numerical models, and evaluation of results. Results from this calculation are limited to use for design of the emplacement drifts and the final ground support system installed in these drifts. The design of non-emplacement openings and their ground support systems is covered in the ''Ground Control for Non-Emplacement Drifts for LA'' (BSC 2004c).

  19. Vegetation-modulated landscape evolution: Effects of vegetation on landscape processes, drainage density, and topography

    Science.gov (United States)

    Istanbulluoglu, Erkan; Bras, Rafael L.

    2005-06-01

    Topography acts as a template for numerous landscape processes that include hydrologic, ecologic, and biologic phenomena. These processes not only interact with each other but also contribute to shaping the landscape as they influence geomorphic processes. We have investigated the effects of vegetation on thresholds for channel initiation and landform evolution using both analytical and numerical approaches. Vegetation is assumed to form a uniform ground cover. Runoff erosion is modeled based on a power function of excess shear stress, in which shear stress efficiency is inversely proportional to vegetation cover. This approach is validated using data. Plant effect on slope stability is represented by additional cohesion provided by plant roots. Vegetation cover is assumed to reduce sediment transport rates due to physical creep processes (rainsplash, dry ravel, and expansion and contraction of sediments) according to a negative exponential relationship. Vegetation grows as a function of both available cover and unoccupied space by plants and is killed by geomorphic disturbances (runoff erosion and landsliding) and wildfires. Analytical results suggest that in an equilibrium basin with a fixed vegetation cover, plants may cause a transition in the dominant erosion process at the channel head. A runoff erosion-dominated landscape, under none or poor vegetation cover, may become landslide dominated under a denser vegetation cover. The sign of the predicted relationship between drainage density and vegetation cover depends on the relative influence of vegetation on different erosion phenomena. With model parameter values representative of the Oregon Coast Range (OCR), numerical experiments conducted using the Channel Hillslope Integrated Landscape Development (CHILD) model confirm the findings based on the analytical theory. A highly dissected fluvial landscape emerges when surface is assumed bare. When vegetation cover is modeled, landscape relief increases

  20. COVER

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The outcome of hepatic B virus(HBV)infection is the result of complex interactions between replicating HBV and the innate/adaptive immune system.As an important lectin complement pathway activator,human ficolin-2 is secreted from liver cells and contributes to the clearance of viral infections and lysis of enveloped virions,which has been implicated as an anti-infection innate immune molecule.In this issue,a research group lead by Drs.XiaoLian Zhang and Fengling Luo,investigated the serum and liver tissue ficolin-2

  1. COVER

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    <正>This issue of Virologica Sinica is to celebrate the 100th anniversary of the discovery of "filterable lytic factor" or "bacteriophage"(1915-2015).During the past 100 years,both basic knowledge and applications of bacteriophages have been substantially explored and developed.In recent years,bacteriophage research is booming and holding the hope

  2. Cover

    OpenAIRE

    Frontiers of Biogeography, Editorial Office

    2017-01-01

    Frontiers of Biogeography new logo. This logo feeds on the theme created for the new IBS corporate image, and represents four overlapping hypervolumes in the form of a butterfly’s wings, flying over four niche response curves in the form of hills, mountains and the sea (see Dawson et al. in this issue for details).

  3. Cover

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Soybean growth habit is an important agronomic trait,and related genes have been cloned recently,while the variation of the major gene and how this gene was selected during the soybean breeding in China remain unknown.In the diverse soybean germplasm,it is hard to distinguish the determinate from the semi‐determinate phenotype.The development of functional Indel and CAPS markers from the Gm Tfl1 gene of the Dt1 locus makes it possible to evaluate genotype of the germplasm.The different allele

  4. COVER

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Hepatitis B virus(HBV)infection remains a major global health problem because current therapies rarely eliminate the replicative template of HBV,which is the covalently closed circular DNA(ccc DNA).As an accurate and efficient genome editing tool,clustered regularly interspaced palindromic repeat(CRISPR)-associated(Cas)9 system represents a very promising potential

  5. GAP Land Cover - Tiled Raster

    Data.gov (United States)

    Minnesota Department of Natural Resources — This raster dataset is a detailed (1-acre minimum), hierarchically organized vegetation cover map produced by computer classification of combined two-season pairs of...

  6. Forest Cover Types - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer portrays general forest cover types for the United States. Data were derived from Advanced Very High Resolution Radiometer (AVHRR) composite images...

  7. Using satellite data to monitor land-use land-cover change in North-eastern Latvia.

    Science.gov (United States)

    Fonji, Simon Foteck; Taff, Gregory N

    2014-01-01

    Land-use and land-cover change (LULCC), especially those caused by human activities, is one of the most important components of global environmental change (Jessen 3(rd) edition: 1-526 2005). In this study the effects of geographic and demographic factors on LULCC are analyzed in northeastern Latvia using official estimates from census and vital statistics data, and using remotely sensed satellite imagery (Landsat Thematic Mapper) acquired from 1992 and 2007. The remote sensing images, elevation data, in-situ ground truth and ground control data (using GPS), census and vital statistics data were processed, integrated, and analyzed in a geographic information system (GIS). Changes in six categories of land-use and land-cover (wetland, water, agriculture, forest, bare field and urban/suburban) were studied to determine their relationship to demographic and geographic factors between 1992 and 2007. Supervised classifications were performed on the Landsat images. Analysis of land cover change based on "change-to" categories between the 1992 and 2007 images revealed that changes to forest were the most common type of change (17.1% of pixels), followed by changes to agriculture (8.6%) and the fewest were changes to urban/suburban (0.8%). Integration of population data and land-cover change data revealed key findings: areas near to roads underwent more LULCC and areas far away from Riga underwent less LULCC. Range in elevation was positively correlated with all LULCC categories. Population density was found to be associated with most LULCC categories but the direction of effect was scale dependent. This paper shows how socio-demographic data can be integrated with satellite image data and cartographic data to analyze drivers of LULCC at multiple spatial scales.

  8. Charge density waves in solids

    CERN Document Server

    Gor'kov, LP

    2012-01-01

    The latest addition to this series covers a field which is commonly referred to as charge density wave dynamics.The most thoroughly investigated materials are inorganic linear chain compounds with highly anisotropic electronic properties. The volume opens with an examination of their structural properties and the essential features which allow charge density waves to develop.The behaviour of the charge density waves, where interesting phenomena are observed, is treated both from a theoretical and an experimental standpoint. The role of impurities in statics and dynamics is considered and an

  9. Critical current densities in superconducting materials

    Indian Academy of Sciences (India)

    P Chaddah

    2003-02-01

    We discuss recent research in the area of critical current densities $(J_C)$ in superconductors. This shall cover recent work on newly discovered superconductors, as well as on the magnetic-field dependence of $J_C$.

  10. Land-cover change detection

    Science.gov (United States)

    Chen, Xuexia; Giri, Chandra; Vogelmann, James

    2012-01-01

    Land cover is the biophysical material on the surface of the earth. Land-cover types include grass, shrubs, trees, barren, water, and man-made features. Land cover changes continuously.  The rate of change can be either dramatic and abrupt, such as the changes caused by logging, hurricanes and fire, or subtle and gradual, such as regeneration of forests and damage caused by insects (Verbesselt et al., 2001).  Previous studies have shown that land cover has changed dramatically during the past sevearal centuries and that these changes have severely affected our ecosystems (Foody, 2010; Lambin et al., 2001). Lambin and Strahlers (1994b) summarized five types of cause for land-cover changes: (1) long-term natural changes in climate conditions, (2) geomorphological and ecological processes, (3) human-induced alterations of vegetation cover and landscapes, (4) interannual climate variability, and (5) human-induced greenhouse effect.  Tools and techniques are needed to detect, describe, and predict these changes to facilitate sustainable management of natural resources.

  11. Good covers are algorithmically unrecognizable

    CERN Document Server

    Tancer, Martin

    2012-01-01

    A good cover in R^d is a collection of open contractible sets in R^d such that the intersection of any subcollection is either contractible or empty. Motivated by an analogy with convex sets, intersection patterns of good covers were studied intensively. Our main result is that intersection patterns of good covers are algorithmically unrecognizable. More precisely, the intersection pattern of a good cover can be stored in a simplicial complex called nerve which records which subfamilies of the good cover intersect. A simplicial complex is topologically d-representable if it is isomorphic to the nerve of a good cover in R^d. We prove that it is algorithmically undecidable whether a given simplicial complex is topologically d-representable for any fixed d \\geq 5. As an auxiliary result we prove that if a simplicial complex is PL embeddable into R^d, then it is topologically d-representable. We also supply this result with showing that if a "sufficiently fine" subdivision of a k-dimensional complex is d-represen...

  12. Reduced melt on debris-covered glaciers: investigations from Changri Nup Glacier, Nepal

    NARCIS (Netherlands)

    Vincent, Christian; Wagnon, Patrick; Shea, Joseph M.; Immerzeel, W.W.|info:eu-repo/dai/nl/290472113; Kraaijenbrink, P.D.A.; Shrestha, Dibas; Soruco, Alvaro; Arnaud, Yves; Brun, Fanny; Berthier, E.; Sherpa, Sonam Futi

    2016-01-01

    Approximately 25 % of the glacierized area in the Everest region is covered by debris, yet the surface mass balance of debris-covered portions of these glaciers has not been measured directly. In this study, ground-based measurements of surface elevation and ice depth are combined with terrestrial

  13. Managed Clearings: an Unaccounted Land-cover in Urbanizing Regions

    Science.gov (United States)

    Singh, K. K.; Madden, M.; Meentemeyer, R. K.

    2016-12-01

    Managed clearings (MC), such as lawns, public parks and grassy transportation medians, are a common and ecologically important land cover type in urbanizing regions, especially those characterized by sprawl. We hypothesize that MC is underrepresented in land cover classification schemes and data products such as NLCD (National Land Cover Database) data, which may impact environmental assessments and models of urban ecosystems. We visually interpreted and mapped fine scale land cover with special attention to MC using 2012 NAIP (National Agriculture Imagery Program) images and compared the output with NLCD data. Areas sampled were 50 randomly distributed 1*1km blocks of land in three cities of the Char-lanta mega-region (Atlanta, Charlotte, and Raleigh). We estimated the abundance of MC relative to other land cover types, and the proportion of land-cover types in NLCD data that are similar to MC. We also assessed if the designations of recreation, transportation, and utility in MC inform the problem differently than simply tallying MC as a whole. 610 ground points, collected using the Google Earth, were used to evaluate accuracy of NLCD data and visual interpretation for consistency. Overall accuracy of visual interpretation and NLCD data was 78% and 58%, respectively. NLCD data underestimated forest and MC by 14.4km2 and 6.4km2, respectively, while overestimated impervious surfaces by 10.2km2 compared to visual interpretation. MC was the second most dominant land cover after forest (40.5%) as it covered about 28% of the total area and about 13% higher than impervious surfaces. Results also suggested that recreation in MC constitutes up to 90% of area followed by transportation and utility. Due to the prevalence of MC in urbanizing regions, the addition of MC to the synthesis of land-cover data can help delineate realistic cover types and area proportions that could inform ecologic/hydrologic models, and allow for accurate prediction of ecological phenomena.

  14. High Energy Density Laboratory Astrophysics

    CERN Document Server

    Lebedev, Sergey V

    2007-01-01

    During the past decade, research teams around the world have developed astrophysics-relevant research utilizing high energy-density facilities such as intense lasers and z-pinches. Every two years, at the International conference on High Energy Density Laboratory Astrophysics, scientists interested in this emerging field discuss the progress in topics covering: - Stellar evolution, stellar envelopes, opacities, radiation transport - Planetary Interiors, high-pressure EOS, dense plasma atomic physics - Supernovae, gamma-ray bursts, exploding systems, strong shocks, turbulent mixing - Supernova remnants, shock processing, radiative shocks - Astrophysical jets, high-Mach-number flows, magnetized radiative jets, magnetic reconnection - Compact object accretion disks, x-ray photoionized plasmas - Ultrastrong fields, particle acceleration, collisionless shocks. These proceedings cover many of the invited and contributed papers presented at the 6th International Conference on High Energy Density Laboratory Astrophys...

  15. Impact of forest type and management strategy on avian densities in the Mississippi Alluvial Valley, USA

    Science.gov (United States)

    Twedt, D.J.; Wilson, R.R.; Henne-Kerr, J.L.; Hamilton, R.B.

    1999-01-01

    Avian territory densities were determined from 20 Breeding Bird Censuses in mature (>30 years) bottomland hardwood stand: and 18 Breeding Bird Censuses in young (6-9 years old) cottonwood (Populas deltoides) plantations in the Mississippi Alluvial Valley. Avian species richness, diversity, and territory density were greater (p 0.05). Even so, detrended correspondence analysis based on avian territory densities readily segregated forest types and silvicultural treatments. Timber harvest within bottomland hardwood stands resulted in a shift in bird communities toward those found in cottonwood stands by increasing the densities of early-successional species such as Indigo Bunting (Passerina cyanea), Yellow-breasted Chat (Icteria virens), and Common Yellowthroat (Geothlypis trichas). Conversely, regenerating cottonwood stands from root sprouts, rather than planting stem cuttings, resulted in a shift in bird communities toward those found in bottomland hardwood stands by increasing densities of species such as White-eyed Vireo (Vireo griseus) and Wood Thrush (Hylocichla mustelina). Tree species diversity, angular canopy cover, and midstory density were positively associated with bird species assemblages in bottomland hardwood stands, whereas vegetation density at ground level was positively associated with bird communities in cottonwood plantations. Conversion of agricultural fields to short-rotation cottonwood plantations results in increased breeding bird populations by adding up to 140 additional territories 40 ha-1. Even so, relative conservation values, derive, from indicator species analysis and Partners in Flight concern scores, suggest that mature bottomland hardwood forests are twice as 'valuable' for bird conservation as are cottonwood plantations.

  16. Cover crops to improve soil health and pollinator habitat in nut orchards: Part II

    Science.gov (United States)

    Jerry. Van Sambeek

    2017-01-01

    Integrating cover crops into a nut orchard can have some unique benefits and problems not found when used cover crops during the fallow period between cash crops. Studies show ground covers can reduce hardwood tree growth anywhere from a few percent to more than 70 percent in the case of tall fescue. This means if it takes 3 years to put on one inch of diameter growth...

  17. Changes in Snow Cover Characteristics over Northern Eurasia since 1966

    Science.gov (United States)

    Bulygina, Olga; Groisman, Pavel; Razuvaev, Vyacheslav; Korshunova, Natalia

    2010-05-01

    Data. In addition to a standard suite of snow observations across Northern Eurasia and its surroundings, we used in our study the national snow survey data set archived at the Russian Institute for Hydrometeorological Information. The last dataset has routine snow surveys run throughout the cold season each decade (during the intense snowmelt, each 5 days) at all meteorological stations of the former USSR, thereafter, in Russia since 1966. Prior to 1966 snow surveys are also available but the methodology of observations has substantially changed at that year. Therefore, this analysis includes only data of more than1000 Russian stations from 1966 to 2009 that have a minimal number of missing observations. Surveys run separately along all types of environment typical for the site for 1 to 2 km, describing the current snow cover properties such as snow density, depth, water equivalent, and characteristics of snow and ice crust. Background. During the past 128 years (since 1881), the annual surface air temperature in Northern Eurasia has increased by 1.5° C and in the winter season by 3° C. Nearby to the north in the Arctic Ocean, the late summer sea ice extent decreased by 40% exposing a near-infinite source of water vapor for the dry Arctic atmosphere in early cold season months. As a result of these processes the following changes in snow cover characteristics have been observed: (a) in autumn the dates of the onset of snow cover have not changed noticeably despite the strong temperature increase in this season; (b) in late spring, snow cover extent has decreased, retreating by 1 to 2 weeks earlier during the past 40 years; and (c) in the cold season maximum snow depth and SWE (at open areas) have increased over most of Russia. In the western half of Eurasian continent days with thaw became more frequent. Snowmelt duration and ice crust changes. Over Northern Eurasia, the snowmelt process can be lengthy but even the first such melt initiates a process of snow

  18. Land Use and Land Cover Change, Urban Heat Island Phenomenon, and Health Implications: A Remote Sensing Approach

    Science.gov (United States)

    Lo, C. P.; Quattrochi, Dale A.

    2003-01-01

    Land use and land cover maps of Atlanta Metropolitan Area in Georgia were produced from Landsat MSS and TM images for 1973,1979,1983,1987,1992, and 1997, spanning a period of 25 years. Dramatic changes in land use and land cover have occurred with loss of forest and cropland to urban use. In particular, low-density urban use, which includes largely residential use, has increased by over 119% between 1973 and 1997. These land use and land cover changes have drastically altered the land surface characteristics. An analysis of Landsat images revealed an increase in surface temperature and a decline in NDVI from 1973 to 1997. These changes have forced the development of a significant urban heat island effect and an increase in ground level ozone production to such an extent, that Atlanta has violated EPA's ozone level standard in recent years. The urban heat island initiated precipitation events that were identified between 1996 and 2000 tended to occur near high-density urban areas but outside the I-285 loop that traverses around the Central Business District, i.e. not in the inner city area, but some in close proximity to the highways. The health implications were investigated by comparing the spatial patterns of volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions, the two ingredients that form ozone by reacting with sunlight, with those of rates of cardiovascular and chronic lower respiratory diseases. A clear core-periphery pattern was revealed for both VOC and NOx emissions, but the spatial pattern was more random in the cases of rates of cardiovascular and chronic lower respiratory diseases. Clearly, factors other than ozone pollution were involved in explaining the rates of these diseases. Further research is therefore needed to understand the health geography and its relationship to land use and land cover change as well as urban heat island effect. This paper illustrates the usefulness of a remote sensing approach for this purpose.

  19. Covering Numbers for Convex Functions

    CERN Document Server

    Guntuboyina, Adityanand

    2012-01-01

    In this paper we study the covering numbers of the space of convex and uniformly bounded functions in multi-dimension. We find optimal upper and lower bounds for the $\\epsilon$-covering number of $\\C([a, b]^d, B)$, in the $L_p$-metric, $1 \\le p 0$, and $\\C([a,b]^d, B)$ denotes the set of all convex functions on $[a, b]^d$ that are uniformly bounded by $B$. We summarize previously known results on covering numbers for convex functions and also provide alternate proofs of some known results. Our results have direct implications in the study of rates of convergence of empirical minimization procedures as well as optimal convergence rates in the numerous convexity constrained function estimation problems.

  20. The National Land Cover Database

    Science.gov (United States)

    Homer, Collin H.; Fry, Joyce A.; Barnes, Christopher A.

    2012-01-01

    The National Land Cover Database (NLCD) serves as the definitive Landsat-based, 30-meter resolution, land cover database for the Nation. NLCD provides spatial reference and descriptive data for characteristics of the land surface such as thematic class (for example, urban, agriculture, and forest), percent impervious surface, and percent tree canopy cover. NLCD supports a wide variety of Federal, State, local, and nongovernmental applications that seek to assess ecosystem status and health, understand the spatial patterns of biodiversity, predict effects of climate change, and develop land management policy. NLCD products are created by the Multi-Resolution Land Characteristics (MRLC) Consortium, a partnership of Federal agencies led by the U.S. Geological Survey. All NLCD data products are available for download at no charge to the public from the MRLC Web site: http://www.mrlc.gov.

  1. Mekong Land Cover Dasboard: Regional Land Cover Mointoring Systems

    Science.gov (United States)

    Saah, D. S.; Towashiraporn, P.; Aekakkararungroj, A.; Phongsapan, K.; Triepke, J.; Maus, P.; Tenneson, K.; Cutter, P. G.; Ganz, D.; Anderson, E.

    2016-12-01

    SERVIR-Mekong, a USAID-NASA partnership, helps decision makers in the Lower Mekong Region utilize GIS and Remote Sensing information to inform climate related activities. In 2015, SERVIR-Mekong conducted a geospatial needs assessment for the Lower Mekong countries which included individual country consultations. The team found that many countries were dependent on land cover and land use maps for land resource planning, quantifying ecosystem services, including resilience to climate change, biodiversity conservation, and other critical social issues. Many of the Lower Mekong countries have developed national scale land cover maps derived in part from remote sensing products and geospatial technologies. However, updates are infrequent and classification systems do not always meet the needs of key user groups. In addition, data products stop at political boundaries and are often not accessible making the data unusable across country boundaries and with resource management partners. Many of these countries rely on global land cover products to fill the gaps of their national efforts, compromising consistency between data and policies. These gaps in national efforts can be filled by a flexible regional land cover monitoring system that is co-developed by regional partners with the specific intention of meeting national transboundary needs, for example including consistent forest definitions in transboundary watersheds. Based on these facts, key regional stakeholders identified a need for a land cover monitoring system that will produce frequent, high quality land cover maps using a consistent regional classification scheme that is compatible with national country needs. SERVIR-Mekong is currently developing a solution that leverages recent developments in remote sensing science and technology, such as Google Earth Engine (GEE), and working together with production partners to develop a system that will use a common set of input data sources to generate high

  2. Kummer covers and braid monodromy

    CERN Document Server

    Bartolo, Enrique Artal; Ortigas-Galindo, Jorge

    2012-01-01

    In this work we describe a method to reconstruct the braid monodromy of the preimage of a curve by a Kummer cover. This method is interesting, since it combines two techniques, namely, the reconstruction of a highly non-generic braid monodromy with a systematic method to go from a non-generic to a generic braid monodromy. This "generification" method is independent from Kummer covers and can be applied in more general circumstances since non generic braid monodromies appear more naturally and are oftentimes much easier to compute. Explicit examples are computed using these techniques.

  3. Optimization of composite sandwich cover panels subjected to compressive loadings

    Science.gov (United States)

    Cruz, Juan R.

    1991-01-01

    An analysis and design method is presented for the design of composite sandwich cover panels that include the transverse shear effects and damage tolerance considerations. This method is incorporated into a sandwich optimization computer program entitled SANDOP. As a demonstration of its capabilities, SANDOP is used in the present study to design optimized composite sandwich cover panels for for transport aircraft wing applications. The results of this design study indicate that optimized composite sandwich cover panels have approximately the same structural efficiency as stiffened composite cover panels designed to satisfy individual constraints. The results also indicate that inplane stiffness requirements have a large effect on the weight of these composite sandwich cover panels at higher load levels. Increasing the maximum allowable strain and the upper percentage limit of the 0 degree and +/- 45 degree plies can yield significant weight savings. The results show that the structural efficiency of these optimized composite sandwich cover panels is relatively insensitive to changes in core density. Thus, core density should be chosen by criteria other than minimum weight (e.g., damage tolerance, ease of manufacture, etc.).

  4. Airport Ground Staff Scheduling

    DEFF Research Database (Denmark)

    Clausen, Tommy

    travels safely and efficiently through the airport. When an aircraft lands, a significant number of tasks must be performed by different groups of ground crew, such as fueling, baggage handling and cleaning. These tasks must be complete before the aircraft is able to depart, as well as check......-in and security services. These tasks are collectively known as ground handling, and are the major source of activity with airports. The business environments of modern airports are becoming increasingly competitive, as both airports themselves and their ground handling operations are changing to private...... ownership. As airports are in competition to attract airline routes, efficient and reliable ground handling operations are imperative for the viability and continued growth of both airports and airlines. The increasing liberalization of the ground handling market prompts ground handling operators...

  5. [Introduction to grounded theory].

    Science.gov (United States)

    Wang, Shou-Yu; Windsor, Carol; Yates, Patsy

    2012-02-01

    Grounded theory, first developed by Glaser and Strauss in the 1960s, was introduced into nursing education as a distinct research methodology in the 1970s. The theory is grounded in a critique of the dominant contemporary approach to social inquiry, which imposed "enduring" theoretical propositions onto study data. Rather than starting from a set theoretical framework, grounded theory relies on researchers distinguishing meaningful constructs from generated data and then identifying an appropriate theory. Grounded theory is thus particularly useful in investigating complex issues and behaviours not previously addressed and concepts and relationships in particular populations or places that are still undeveloped or weakly connected. Grounded theory data analysis processes include open, axial and selective coding levels. The purpose of this article was to explore the grounded theory research process and provide an initial understanding of this methodology.

  6. The repair of ground cover of Bolivia-Brazil gas pipeline near Paraguay River crossing, in a swamp soft soil region, using geo synthetics reinforced backfilling; Reparo da cobertura do gasoduto Bolivia-Brasil junto ao Rio Paraguai, em trecho com solo mole, utilizando aterro reforcado com geosinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Cesar Augusto; Jorge, Kemal Vieira; Bechuate Filho, Pedro [TBG - Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Campo Grande, MS (Brazil). Gerencia Regional Centro Oeste (CRGO); Teixeira, Sidnei H.C. [Geohydrotech Engenharia S.C. Ltda., Braganca Paulista, SP (Brazil)

    2005-07-01

    TBG - Transportadora Gasoduto Bolivia-Brasil S.A, executes routine maintenance works at the Gas Pipeline Right of Way, seeking its integrity. In the wetlands of Pantanal, near the Paraguay river crossing, the organic-alluvial soil was submitted to the process of subsidence. This process, associated with the river water flow erosion, shrank the soil volume and diminished or extinguished the pipeline land cover. The pipeline was exposed to the environment, and submitted to tension stresses and the risk of low cycle fatigue during the floods. The cathodic protection system also had to be evaluated, specially in the drought. To mitigate the problem, the embankment technique was adopted using sandy soil, reinforced with polyester geo-webs and with woven polipropene geo-textiles. The solution also used geo-webs with soil-cement as protection elements against the degradation of the geo-textiles blankets. Some monitoring works are associated with those interventions: monitoring of cathodic protection; topographical verification of horizontal and vertical displacements of the pipeline; levels of land covering, and rainfalls and flood measurement. The base of the embankment was built with hydraulic transported soil, and at the end consistently supported the gas pipeline. (author)

  7. Vegetation modulated landscape evolution: Effects of vegetation on landscape processes, drainage density and topography

    Science.gov (United States)

    Bras, R. L.; Istanbulluoglu, E.

    2004-12-01

    Topography acts as a template for numerous landscape processes that includes hydrologic, ecologic and biologic phenomena. These processes not only interact with each other but also contribute to shaping the landscape as they influence geomorphic processes. We have investigated the effects of vegetation on known geomorphic relations, thresholds for channel initiation and landform evolution, using both analytical and numerical approaches. Vegetation is assumed to form a uniform ground cover. Runoff erosion is modeled based on power function of excess shear stress, in which shear stress efficiency is inversely proportional to vegetation cover. Plant effect on slope stability is represented by additional cohesion provided by plant roots. Vegetation cover is assumed to reduce sediment transport rates due to physical creep processes (rainsplash, dry ravel, and expansion and contraction of sediments) according to a negative exponential relationship. Vegetation grows as a function of both available cover and unoccupied space by plants, and is killed by geomorphic disturbances (runoff erosion and landsliding), and wildfires. Analytical results suggest that, in an equilibrium basin with a fixed vegetation cover, plants may cause a transition in the dominant erosion process at the channel head. A runoff erosion dominated landscape, under none or loose vegetation cover, may become landslide dominated under a denser vegetation cover. The sign of the predicted relationship between drainage density and vegetation cover depends on the relative influence of vegetation on different erosion phenomena. With model parameter values representative of the Oregon Coast Range (OCR), numerical experiments conducted using the CHILD model. Numerical experiments reveal the importance of vegetation disturbances on the landscape structure. Simulated landscapes resemble real-world catchments in the OCR when vegetation disturbances are considered.

  8. The Grounded Theory Bookshelf

    Directory of Open Access Journals (Sweden)

    Vivian B. Martin, Ph.D.

    2005-03-01

    Full Text Available Bookshelf will provide critical reviews and perspectives on books on theory and methodology of interest to grounded theory. This issue includes a review of Heaton’s Reworking Qualitative Data, of special interest for some of its references to grounded theory as a secondary analysis tool; and Goulding’s Grounded Theory: A practical guide for management, business, and market researchers, a book that attempts to explicate the method and presents a grounded theory study that falls a little short of the mark of a fully elaborated theory.Reworking Qualitative Data, Janet Heaton (Sage, 2004. Paperback, 176 pages, $29.95. Hardcover also available.

  9. Gambia Land Use Land Cover

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This series of three-period land use land cover (LULC) datasets (1975, 2000, and 2013) aids in monitoring change in West Africa’s land resources (exception is...

  10. Emerging Infectious Diseases Cover Art

    Centers for Disease Control (CDC) Podcasts

    2017-07-26

    Byron Breedlove, managing editor of the EID Journal, discusses his approach to cover art.  Created: 7/26/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/26/2017.

  11. Covering Numbers for Semicontinuous Functions

    Science.gov (United States)

    2016-04-29

    di Matematica pura ed applicata, CLX:303–320, 1991. [3] H. Attouch and R. J-B Wets. A convergence theory for saddle functions. Transactions of the...P. L. Bartlett, J. Shawe-Taylor, and R. C. Williamson. Covering numbers for support vector machines. IEEE Transactions on Information Theory, 48(1

  12. Transmittance spectroscopy and transmitted multispectral imaging to map covered paints

    Directory of Open Access Journals (Sweden)

    Antonino Cosentino

    2016-01-01

    Full Text Available Transmitted spectroscopy and transmitted multispectral imaging in the 400-900 nm range have been applied for the mapping and tentative identification of paints covered by a white preparation as in the case of a ground laid for reusing a canvas for another painting. These methods can be applied to polychrome works of art, as long as their support and new preparation are sufficiently translucent. This work presents the transmittance spectra acquired from a test board consisting of a prepared canvas with swatches of 54 pigments covered with titanium white and the multispectral images realized with transmitted light to map covered paints on a mock-up painting. It was observed that 18 out of 54 historical pigments provide characteristic transmittance spectra even underneath a titanium white preparation layer and that transmitted light multispectral imaging can map hidden paint layers.

  13. Rearrangements in ground and excited states

    CERN Document Server

    de Mayo, Paul

    1980-01-01

    Rearrangements in Ground and Excited States, Volume 2 covers essays on the theoretical approach of rearrangements; the rearrangements involving boron; and the molecular rearrangements of organosilicon compounds. The book also includes essays on the polytopal rearrangement at phosphorus; the rearrangement in coordination complexes; and the reversible thermal intramolecular rearrangements of metal carbonyls. Chemists and people involved in the study of rearrangements will find the book invaluable.

  14. Is space the ultimate high ground?

    Science.gov (United States)

    Meyer, Gregory J.; Stallings, Francis P.

    2011-06-01

    Military experts often refer to space as the ultimate high ground under the premise that placing systems in orbit provides advantages consistent with the military doctrine of high ground. Although space provides the ultimate "observation post", it has none of the other advantages traditionally associated with high ground. Army Field Manual (FM) 34-130 states the other advantages of holding key terrain: commanding avenues of approach, overcoming obstacles, and affording cover and concealment as additional benefits of high ground. Yet systems in orbit incur none of these additional advantages. Finally, international restrictions and reciprocity concerns limit the employment of weapons in space nullifying many of the unique capability advantages that would otherwise support the "high ground" aspect of space. As the ultimate observation post, satellites provide a large quantity of vital data to military decision makers. This massive amount of data needs to have as much context as possible to convert this data to useful knowledge. To use space assets optimally, the military needs to learn from the past and make space and cyber products distributed and tactical. It is absolutely essential to distribute the right information to the lowest level (tactical elements) of the organization or the "boots on the ground" in a timely manner.

  15. Implementation of a ground truth process for development of a submerged aquatic vegetation (SAV) mapping protocol using hyperspectral imagery

    Science.gov (United States)

    Hall, Carlton R.; Bostater, Charles R., Jr.; Virnstein, Robert W.

    2006-09-01

    Protocol development for science based mapping of submerged aquatic vegetation (SAV) requires comprehensive ground truth data describing the full range of variability observed in the target. The Indian River Lagoon, Florida, extends along 250 km of the east central Florida coast adjacent to the Atlantic Ocean. The lagoon crosses the transition zone between the Caribbean and Carolinian zoogeographic provinces making it highly diverse. For large scale mapping and management of SAV four common and three uncommon species of seagrass (Tracheophyta) and three broad groups of macroalgae; red algae (Rhodophyta), green algae (Chlorophyta), and brown algae (Phaeophyta) are recognized. Based on technical and cost limitations we established twenty, 7-10 km long flight transects for collection of 1.2 m2 spatial resolution hyperspectral imagery covering the length of the lagoon. Emphasis was placed on the area near the Sebastian River and adjacent Sebastian Inlet. Twenty six 40 m long ground truth transects were established in the lagoon using 1 m2 white panels to mark each transect end. Each transect target was located in the field using high precision GPS. Transects were positioned to cover a range of depths, SAV densities, mixed and monotypic species beds, water quality conditions and general sediment types. A 3 m wide by 30 m long grid was centered on each transect to avoid spectral influences of the white targets. Water depth, species of seagrasses, estimates of vegetation cover percentage, estimates of epiphytic density, and measured canopy height were made for each 1 m2 (n=90). This target based grid arrangement allows for identification and extraction of pixel based hyperspectral signatures corresponding to individual ground truth grid cells without significant concern for rectification and registration error.

  16. Confronting remote sensing product with ground base measurements across time and scale

    Science.gov (United States)

    Pourmokhtarian, A.; Dietze, M.

    2015-12-01

    Ecosystem models are essential tools in forecasting ecosystem responses to global climate change. One of the most challenging issues in ecosystem modeling is scaling while preserving landscape characteristics and minimizing loss of information, when moving from point observation to regional scale. There is a keen interest in providing accurate inputs for ecosystem models which represent ecosystem initial state conditions. Remote sensing land cover products, such as Landsat NLCD and MODIS MCD12Q1, provide extensive spatio-temporal coverage but do not capture forest composition and structure. Lidar and hyperspectral have the potential to meet this need but lack sufficient spatial and historical coverage. Forest inventory measurements provide detailed information on the landscape but in a very small footprint. Combining inventory and land cover could improve estimates of ecosystem state and characteristic across time and space. This study focuses on the challenges associated with fusing and scaling the US Forest Service FIA database and NLCD across regional scales to quantify ecosystem characteristics and reduce associated uncertainties. Across Southeast of U.S. 400 stratified random samples of 10x10 km2 landscapes were selected. Data on plant density, species, age, and DBH of trees in FIA plots within each site were extracted. Using allometry equations, the canopy cover of different plant functional types (PFTs) was estimated using a PPA-style canopy model and used to assign each inventory plot to a land cover class. Inventory and land cover were fused in a Bayesian model that adjusts the fractional coverage of inventory plots while accounting for multiple sources of uncertainty. Results were compared to estimates derived from inventory alone, land cover alone, and model spin-up alone. Our findings create a framework of data assimilation to better interpret remote sensing data using ground-based measurements.

  17. A NOVEL FUZZY PARAMETER FOR GROUND FLASH DENSITY

    Directory of Open Access Journals (Sweden)

    CAMILO YOUNES

    2013-01-01

    Full Text Available Algunos parámetros del rayo, tales como la densidad de descargas a tierra DDT se han determinado usando principalmente métodos determinísticos y en los últimos 20 años la principal fuente de información han sido los datos de los sistemas de localización de rayos (SLR. La DDT tiene algunos problemas como la dependencia del área de la malla que se va a estudiar, las fuertes variaciones entre los datos en puntos cercanos de la malla y su baja capacidad descriptiva. Adicionalmente los SLR introducen más problemas debidos a la precisión en la localización que debe estar en acuerdo con el área de la malla que se va a estudiar. Este artículo presenta un parámetro difuso novedoso para calcular la densidad de descargas a tierra usando técnicas computacionales modernas. El nuevo parámetro llamado Densidad Difusa de Descargas a Tierra (DDDT puede tratar con los problemas relacionados al parámetro de DDT en sí y con la precisión en la localización de los SLR. La DDDT proporciona una mejor representación del fenómeno y es más adecuado para problemas prácticos, especialmente en temas de ingeniería tales como diseño de sistemas de localización de rayos y evaluación de riesgos por rayo. Algunos ejemplos fueron creados para demostrar la validez del nuevo parámetro y se muestra también un caso real usando datos de un SLR Colombiano.

  18. The Nature of Partial Covering in Broad Absorption Line Quasars

    Science.gov (United States)

    Leighly, Karen

    2012-10-01

    Ejected gas is seen as broad absorption lines in 20% of quasars. It has been known for 15 years that prominent lines such as CIV are usually saturated but not black because the absorbing gas only partially covers the continuum emission region. Therefore, column densities estimated from these lines are only lower limits. Accurate column densities can be obtained from rare ions that have two or more transitions from the same lower level, so that the optical depth and covering fraction can be solved for simultanously. Suitable lines are hard to find, so such measurements are rare. We have found that metastable helium is particularly useful for these measurements. Yet despite these advances, partial covering remains a just a parameter and its physical nature is not understood.We propose a unique experiment to constrain the physical nature of partial covering. We will compare the covering fraction measured from PV {a doublet in the far UV} with that measured from metastable HeI {optical and IR}. The ions creating these lines are relatively rare, and they present similar opacity over a wide range of gas parameters. But due to their wide wavelength separation, these lines probe dramatically different regions of the continuum source, the temperature-dependent accretion disk. So we expect different covering fraction behavior for different partial covering scenarios. This experiment is relevant for understanding the geometry and clumpiness of the outflow, and the results may impact our understanding of the global covering fraction, a parameter critical for determining the outflow kinetic luminosity, and thereby estimating feedback efficiency for broad absorption line outflows.

  19. Pesticides in Ground Water

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup

    1996-01-01

    Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

  20. Pesticides in Ground Water

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup

    1996-01-01

    Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

  1. Airborne Crowd Density Estimation

    Science.gov (United States)

    Meynberg, O.; Kuschk, G.

    2013-10-01

    This paper proposes a new method for estimating human crowd densities from aerial imagery. Applications benefiting from an accurate crowd monitoring system are mainly found in the security sector. Normally crowd density estimation is done through in-situ camera systems mounted on high locations although this is not appropriate in case of very large crowds with thousands of people. Using airborne camera systems in these scenarios is a new research topic. Our method uses a preliminary filtering of the whole image space by suitable and fast interest point detection resulting in a number of image regions, possibly containing human crowds. Validation of these candidates is done by transforming the corresponding image patches into a low-dimensional and discriminative feature space and classifying the results using a support vector machine (SVM). The feature space is spanned by texture features computed by applying a Gabor filter bank with varying scale and orientation to the image patches. For evaluation, we use 5 different image datasets acquired by the 3K+ aerial camera system of the German Aerospace Center during real mass events like concerts or football games. To evaluate the robustness and generality of our method, these datasets are taken from different flight heights between 800 m and 1500 m above ground (keeping a fixed focal length) and varying daylight and shadow conditions. The results of our crowd density estimation are evaluated against a reference data set obtained by manually labeling tens of thousands individual persons in the corresponding datasets and show that our method is able to estimate human crowd densities in challenging realistic scenarios.

  2. Communication, concepts and grounding.

    Science.gov (United States)

    van der Velde, Frank

    2015-02-01

    This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain and communication between humans or between humans and machines. In the first form of communication, a concept is activated by sensory input. Due to grounding, the information provided by this communication is not just determined by the sensory input but also by the outgoing connection structure of the conceptual representation, which is based on previous experiences and actions. The second form of communication, that between humans or between humans and machines, is influenced by the first form. In particular, a more successful interpersonal communication might require forms of situated cognition and interaction in which the entire representations of grounded concepts are involved.

  3. Stochastic ground motion simulation

    Science.gov (United States)

    Rezaeian, Sanaz; Xiaodan, Sun; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan

    2014-01-01

    Strong earthquake ground motion records are fundamental in engineering applications. Ground motion time series are used in response-history dynamic analysis of structural or geotechnical systems. In such analysis, the validity of predicted responses depends on the validity of the input excitations. Ground motion records are also used to develop ground motion prediction equations(GMPEs) for intensity measures such as spectral accelerations that are used in response-spectrum dynamic analysis. Despite the thousands of available strong ground motion records, there remains a shortage of records for large-magnitude earthquakes at short distances or in specific regions, as well as records that sample specific combinations of source, path, and site characteristics.

  4. Ground energy coupling

    Science.gov (United States)

    Metz, P. D.

    The feasibility of ground coupling for various heat pump systems was investigated. Analytical heat flow models were developed to approximate design ground coupling devices for use in solar heat pump space conditioning systems. A digital computer program called GROCS (GRound Coupled Systems) was written to model 3-dimensional underground heat flow in order to simulate the behavior of ground coupling experiments and to provide performance predictions which have been compared to experimental results. GROCS also has been integrated with TRNSYS. Soil thermal property and ground coupling device experiments are described. Buried tanks, serpentine earth coils in various configurations, lengths and depths, and sealed vertical wells are being investigated. An earth coil used to heat a house without use of resistance heating is described.

  5. The impact of daily covers on sidewall leakage in landfills

    Energy Technology Data Exchange (ETDEWEB)

    Welker, A. L. [Villanova Univ., Dept. of Civil Engineering, PA (United States)

    2000-09-01

    Typically, sanitary landfills are covered by 15 cm of locally available soil on a daily basis. This practice is intended to limit short term negative effects of the waste material on the above-ground environment such as odor, fire, or vermin attraction. Daily placement of compacted soil creates low hydraulic conductivity stratifying layers within the landfill which, in due course, may result in side-slope seepage, decreased stability and decreased efficiency of methane gas venting. The expense of soil acquisitions and the the diminishing availability of landfill space increases the need for alternative materials to replace the daily cover. This paper examines the the threat of sidewall landfill leakage for a hypothetical landfill with traditional soil cover and an alternative daily cover, to demonstrate that the threat of sidewall leakage is real and can be decreased with the use of alternative material as the daily cover such as crushed glass, sludge from waste-water treatment plants, industrial waste, foams and various geosynthetics. At the same time, results of the modelling study showed that with proper drainage sidewall seepage will not occur even with a daily cover that has a hydraulic conductivity two orders of magnitude smaller than the waste, despite positive pressure building up on top of the daily cover. These results imply that the threat of sidewall leakage is minimal, and while alternative daily cover material would help to reduce it even further, their use is most likely to be the result of economic, not technical, considerations. 12 refs., 3 tabs., 4 figs.

  6. Prym varieties of spectral covers

    CERN Document Server

    Hausel, Tamás

    2010-01-01

    Given a possibly reducible and non-reduced spectral cover X over a smooth projective complex curve C we determine the group of connected components of the Prym variety Prym(X/C). We also describe the sublocus of characteristics a for which the Prym variety Prym(X_a/C) is connected. These results extend special cases of work of Ng\\^o who considered integral spectral curves.

  7. Slotted Antenna with Anisotropic Covering

    Science.gov (United States)

    2015-08-06

    08-2015 Publication Slotted Antenna with Anisotropic Covering David A. Tonn et al Naval Under Warfare Center Division, Newport 1176 Howell St...NUWC 300055 Distribution A An antenna includes a tubular, conductive radiator having a longitudinal slot formed therein from a first end of the...conductive radiator to a second end of the conductive radiator. An antenna feed can be joined to the conductive radiator adjacent to and across the slot

  8. Differences in breeding bird assemblages related to reed canary grass cover cover and forest structure on the Upper Mississippi River

    Science.gov (United States)

    Kirsch, Eileen M.; Gray, Brian R.

    2017-01-01

    Floodplain forest of the Upper Mississippi River provides habitat for an abundant and diverse breeding bird community. However, reed canary grass Phalaris arundinacea invasion is a serious threat to the future condition of this forest. Reed canary grass is a well-known aggressive invader of wetland systems in the northern tier states of the conterminous United States. Aided by altered flow regimes and nutrient inputs from agriculture, reed canary grass has formed dense stands in canopy gaps and forest edges, retarding tree regeneration. We sampled vegetation and breeding birds in Upper Mississippi River floodplain forest edge and interior areas to 1) measure reed canary grass cover and 2) evaluate whether the breeding bird assemblage responded to differences in reed canary grass cover. Reed canary grass was found far into forest interiors, and its cover was similar between interior and edge sites. Bird assemblages differed between areas with more or less reed canary grass cover (.53% cover breakpoint). Common yellowthroat Geothlypis trichas, black-capped chickadee Parus atricapillus, and rose-breasted grosbeak Pheucticus ludovicianus were more common and American redstart Setophaga ruticilla, great crested flycatcher Myiarchus crinitus, and Baltimore oriole Icterus galbula were less common in sites with more reed canary grass cover. Bird diversity and abundance were similar between sites with different reed canary grass cover. A stronger divergence in bird assemblages was associated with ground cover ,15%, resulting from prolonged spring flooding. These sites hosted more prothonotary warbler Protonotaria citrea, but they had reduced bird abundance and diversity compared to other sites. Our results indicate that frequently flooded sites may be important for prothonotary warblers and that bird assemblages shift in response to reed canary grass invasion.

  9. EFFECTS OF EDGE COVERING ON TENSILE STRENGTH OF MDF

    Directory of Open Access Journals (Sweden)

    Yalçın ÖRS

    1999-03-01

    Full Text Available Dowels, 6, 8 and 10 mm ? diameters were bonded with PVAc adhesive on Medium Density Fiberboard (MDF. Edges were covered with 5, 8 and 12 mm beech wood materials, drilled 25 mm depth. Tensile strength measurments were made on the samples. The highest tensile strength value was given as 6 mm ? dowel and MDF covered with 8 mm thickness beech wood material (2.294 N/mm2, the lowest value was obtained with 10 mm ? dowel and with unprocessed MDF (1.314 N/mm2.

  10. Design of primary ground support during roadway development using empirical databases

    Institute of Scientific and Technical Information of China (English)

    Ry Stone⇑

    2016-01-01

    There have been many design practices utilised within the coal mining industry to arrive at the minimum densities of primary ground support required during roadway development. This paper demonstrates the practical use of empirical databases, and focuses on the main drivers for ground support as demonstrated in conceptual models. Golder Associates’ empirical databases used for ground support include a primary roof support database and a primary rib support database. Both are based on successful ground support designs installed in mines in Australia, the US, the UK, South Africa, New Zealand, and Europe. The term‘successful”refers to those designs that were used on a repeated basis for the purpose of roadway devel-opment. The primary roof support database indicates that the major factors influencing successful roof support designs are roof competency, expressed as the coal mine roof rating (CMRR), and in situ stress. In regard to the primary rib support database, it is evident from the current database that the primary factors affecting the capacity of rib support required for a successful design are roadway height and depth of cover. These databases have been used to help determine the minimum primary ground support designs required at many mine sites in Australasia, Europe, and the US. This paper will demonstrate the effectiveness and practicality of these databases at two selected mines in Australia and the US. In order to improve the primary rib support database, this paper will also propose a new rib deformation rating based on the addition of site specific coal strength data for the Australian mines. The proposed rat-ing attempts to capture the main variables that define the behaviour of a buckling column.

  11. Land cover detection with SAR images of Delta del Llobregat

    Science.gov (United States)

    Godinho, R.; Borges, P. A. V.; Calado, H.; Broquetas, A.

    2016-08-01

    This work presents a study of a multitemporal set of C-band images collected by ERS-2, aiming to understand the differentiations of the backscatter intensity and the phase coherence of different land covers to find possible synergies that could improve land cover detection. The land cover analysis allowed to observe the perfect differentiation of urban areas from intensity images. The observation of multitemporal RGB compositions combining key dates of the different points of crops growth make possible to differentiate this land cover and also to observe fluctuations inside the class itself. This fluctuations present a pattern that correspond to the crop field structure, which suggests that more information can be obtained. The shrubs are difficult to detect from the intensity images, but once the observation is combined with coherence images the detection is possible. However, the coherence image must be generated from pairs of images with a temporal interval lower than three months, independently from the year of registration of each image due to the general decrease of coherence when larger intervals are used. The analysis allowed to observe the potential of this data to perfect distinguish urban, crops and shrubs. The study of the seasonal fluctuations of intensity for the crops land cover with precise ground truth for crops type and points of growth is proposed as a future line of research.

  12. Density Functional Calculations for the Neutron Star Matter at Subnormal Density

    Science.gov (United States)

    Kashiwaba, Yu; Nakatsukasa, Takashi

    The pasta phases of nuclear matter, whose existence is suggested at low density, may influence observable properties of neutron stars. In order to investigate properties of the neutron star matter, we calculate self-consistent solutions for the ground states of slab-like phase using the microscopic density functional theory with Bloch wave functions. The calculations are performed at each point of fixed average density and proton fraction (\\bar{ρ },Yp), varying the lattice constant of the unit cell. For small Yp values, the dripped neutrons emerge in the ground state, while the protons constitute the slab (crystallized) structure. The shell effect of protons affects the thickness of the slab nuclei.

  13. EXACT ALGORITHM FOR BIN COVERING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents a new arc flow model for the one-dimensional bin covering problem and an algorithm to solve the problem exactly through a branch-and-bound procedure and the technique of column generation. The subproblems occuring in the procedure of branch-and-bound have the same structure and therefore can be solved by the same algorithm. In order to solve effectively the subproblems which are generally large scale, a column generation algorithm is employed. Many rules found in this paper can improve the performance of the methods.

  14. Green's conjecture for general covers

    CERN Document Server

    Aprodu, Marian

    2011-01-01

    We establish Green's syzygy conjecture for classes of covers of curves of higher Clifford dimension. These curves have an infinite number of minimal pencils, in particular they do not verify a well-known Brill-Noether theoretic sufficient condition that implies Green's conjecture. Secondly, we study syzygies of curves with a fixed point free involution and prove that sections of Nikulin surfaces of minimal Picard number 9, verify the classical Green Conjecture but fail the Prym-Green Conjecture on syzygies of Prym-canonical curves. This provides an explicit locus in the moduli space R_g where Green's Conjecture is known to hold.

  15. Ground State Spin Logic

    CERN Document Server

    Whitfield, J D; Biamonte, J D

    2012-01-01

    Designing and optimizing cost functions and energy landscapes is a problem encountered in many fields of science and engineering. These landscapes and cost functions can be embedded and annealed in experimentally controllable spin Hamiltonians. Using an approach based on group theory and symmetries, we examine the embedding of Boolean logic gates into the ground state subspace of such spin systems. We describe parameterized families of diagonal Hamiltonians and symmetry operations which preserve the ground state subspace encoding the truth tables of Boolean formulas. The ground state embeddings of adder circuits are used to illustrate how gates are combined and simplified using symmetry. Our work is relevant for experimental demonstrations of ground state embeddings found in both classical optimization as well as adiabatic quantum optimization.

  16. Reconstruction of Layer Densities in a Multilayer Snowpack using a Bayesian Approach to Inverse Modeling

    Science.gov (United States)

    Aguayo, M.; Marshall, H.; McNamara, J. P.; Mead, J.; Flores, A. N.

    2013-12-01

    Estimation of snowpack parameters such as depth, density and grain structure is a central focus of hydrology in seasonally snow-covered lands. These parameters are directly estimated by field observations, indirectly estimated from other parameters using statistical correlations, or simulated with a model. Difficulty in sampling thin layers and uncertainty in the transition between layers can cause significant uncertainty in measurements of these parameters. Snow density is one of the most important parameters to measure because it is strictly related with snow water content, an important component of the global water balance. We develop a mathematical framework to estimate snow density from measurements of temperature and thickness of snowpack layers over a particular time period, in conjunction with a physics-based model of snowpack evolution. We formulate a Bayesian approach to estimate the snowpack density profile, using a full range of possible simulations that incorporate key sources of uncertainty to build in prior snowpack knowledge. The posterior probability density function of the snow density, conditioned on snowpack temperature measurements, is computed by multiplying the likelihoods and assumed prior distribution function. Random sampling is used to generate a range of densities with same probability when prior uniform probability function is assumed. A posterior probability density function calculated directly via Bayes' theorem is used to calculate the probability of every sample generated. The forward model is a 1D, multilayer snow energy and mass balance model, which solves for snow temperature, density, and liquid water content on a finite element mesh. The surface and ground temperature data of snowpack (boundary conditions), are provided by the Center for Snow and Avalanche Studies (CSAS), Silverton CO, from snow pits made at Swamp Angel and Senator Beck study plot sites. Standard errors between field observations and results computed denote the

  17. Tree Cover Mapping Tool—Documentation and user manual

    Science.gov (United States)

    Cotillon, Suzanne E.; Mathis, Melissa L.

    2016-06-02

    The Tree Cover Mapping (TCM) tool was developed by scientists at the U.S. Geological Survey Earth Resources Observation and Science Center to allow a user to quickly map tree cover density over large areas using visual interpretation of high resolution imagery within a geographic information system interface. The TCM tool uses a systematic sample grid to produce maps of tree cover. The TCM tool allows the user to define sampling parameters to estimate tree cover within each sample unit. This mapping method generated the first on-farm tree cover maps of vast regions of Niger and Burkina Faso. The approach contributes to implementing integrated landscape management to scale up re-greening and restore degraded land in the drylands of Africa. The TCM tool is easy to operate, practical, and can be adapted to many other applications such as crop mapping, settlements mapping, or other features. This user manual provides step-by-step instructions for installing and using the tool, and creating tree cover maps. Familiarity with ArcMap tools and concepts is helpful for using the tool.

  18. A new patch antenna with metamaterial cover

    Institute of Scientific and Technical Information of China (English)

    HU Jun; YAN Chun-sheng; LIN Qing-chun

    2006-01-01

    A metamaterial was introduced into the cover of a patch antenna and its band structure was analyzed. The metamaterial cover with correct selection of the working frequency increases by 9.14 dB the patch antenna's directivity. The mechanism of metamaterial cover is completely different from that of a photonic bandgap cover. The mechanism of the metamaterial cover,the number of the cover's layers, and the distance between the layers, were analyzed in detail. The results showed that the metamaterial cover, which works like a lens, could effectively improve the patch antenna's directivity. The physical reasons for the improvement are also given.

  19. Ground-water, surface-water, and bottom-sediment contamination in the O-field area, Aberdeen Proving Ground, Maryland, and the possible effects of selected remedial actions on ground water

    Science.gov (United States)

    Vroblesky, Don A.; Lorah, Michelle M.; Oliveros, James P.

    1995-01-01

    Disposal of munitions and chemical-warfare substances has introduced inorganic and organic contaminants to the ground water, surface water, and bottom sediment at O-Field, in the Edgewood area of Aberdeen Proving Ground, Maryland. Contaminants include chloride, arsenic, transition metals, chlorinated aliphatic hydrocarbons, aromatic compounds, and organosulfur and organophosphorus compounds. The hydrologic effects of several remedial actions were estimated by use of a ground-water-flow model. The remedial actions examined were an impermeable covering, encapsulation, subsurface barriers, a ground-water drain, pumping of wells to manage water levels or to remove contaminated ground water for treatment, and no action.

  20. Potential for Monitoring Snow Cover in Boreal Forests by Combining MODIS Snow Cover and AMSR-E SWE Maps

    Science.gov (United States)

    Riggs, George A.; Hall, Dorothy K.; Foster, James L.

    2009-01-01

    Monitoring of snow cover extent and snow water equivalent (SWE) in boreal forests is important for determining the amount of potential runoff and beginning date of snowmelt. The great expanse of the boreal forest necessitates the use of satellite measurements to monitor snow cover. Snow cover in the boreal forest can be mapped with either the Moderate Resolution Imaging Spectroradiometer (MODIS) or the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) microwave instrument. The extent of snow cover is estimated from the MODIS data and SWE is estimated from the AMSR-E. Environmental limitations affect both sensors in different ways to limit their ability to detect snow in some situations. Forest density, snow wetness, and snow depth are factors that limit the effectiveness of both sensors for snow detection. Cloud cover is a significant hindrance to monitoring snow cover extent Using MODIS but is not a hindrance to the use of the AMSR-E. These limitations could be mitigated by combining MODIS and AMSR-E data to allow for improved interpretation of snow cover extent and SWE on a daily basis and provide temporal continuity of snow mapping across the boreal forest regions in Canada. The purpose of this study is to investigate if temporal monitoring of snow cover using a combination of MODIS and AMSR-E data could yield a better interpretation of changing snow cover conditions. The MODIS snow mapping algorithm is based on snow detection using the Normalized Difference Snow Index (NDSI) and the Normalized Difference Vegetation Index (NDVI) to enhance snow detection in dense vegetation. (Other spectral threshold tests are also used to map snow using MODIS.) Snow cover under a forest canopy may have an effect on the NDVI thus we use the NDVI in snow detection. A MODIS snow fraction product is also generated but not used in this study. In this study the NDSI and NDVI components of the snow mapping algorithm were calculated and analyzed to determine how they changed

  1. INFLUENCE OF DIVIDING COVERINGS ON QUALITY OF CASTINGS AT MOLDING OF ALUMINUM ALLOYS UNDER PRESSURE

    Directory of Open Access Journals (Sweden)

    A. A. Pivovarchik

    2014-01-01

    Full Text Available The results of researches on influence of separating coverings on such properties of castings as corrosion resistance, roughness of cast surface, casting density are given in article.

  2. Commutator coverings of Siegel threefolds

    CERN Document Server

    Gritsenko, V

    1997-01-01

    We investigate the existence and non-existence of modular forms of low weight with a character with respect to the paramodular group $\\Gamma_t$ and discuss the resulting geometric consequences. Using an advanced version of Maa\\ss\\ lifting one can construct many examples of such modular forms and in particular examples of weight 3 cusp forms. Consequently we find many abelian coverings of low degree of the moduli space ${\\Cal A}_t$ of (1,t)-polarized abelian surfaces which are not unirational. We also determine the commutator subgroups of the paramodular group $\\Gamma_t$ and its degree 2 extension $\\Gamma^+_t$. This has applications for the Picard group of the moduli stack ${\\underline{\\Cal A}}_t$. Finally we prove non-existence theorems for low weight modular forms. As one of our main results we obtain the theorem that the maximal abelian cover ${\\Cal A}_t^{com}$ of ${\\Cal A}_t$ has geometric genus 0 if and only if t=1, 2, 4 or 5. We also prove that ${\\Cal A}_t^{com}$ has geometric genus 1 for t=3 and 7.

  3. Evaluation of terrain geomorphometric characteristics for ground clearance charts production

    Directory of Open Access Journals (Sweden)

    Mirko A. Borisov

    2011-01-01

    Full Text Available Geomorphometric exploration applied in the military terrain analysis is based on the GIS methodology of spatial analyses and is related primarily to military terrain analyses. It includes relief assessment aiming at producing ground clearance charts for the analysis of terrain maneuverability and its deployment, cover and concealment possibilities. An evaluation analysis of geomorphological parameters was performed for the Avala test area using a few terrain parameters (visibility, terrain aspect and slope as well as some terrain qualitative categories (e.g. vegetation density. Terrain slope Slope and aspect are morphometric terrain parameters that can be derived directly from the DTM using some GIS operations. Slope is the first derivative of a surface and has both magnitude and direction. Slope is perhaps the most important aspect of the surface form, since surfaces are formed completely of slopes, and slope angles control the gravitational force available for geomorphic work. Mathematically, the tangent of the slope angle is the first derivative of altitude, and it is a tangent or percent slope as this surface parameter is generally referred to. Slope is defined at each point as the slope of a plane tangent to the surface at that point. In practice, however, slope is generally measured over a finite distance, especially when data are obtained from a contour map. Terrain aspect Aspect is also the first derivative of a surface and has both magnitude and direction. The term aspect is defined as the direction of the biggest slope vector on the tangent plane projected onto the horizontal plane. Aspect is the bearing (or azimuth of the slope direction, and its angle ranges from 0 to 360°. Analyses of terrain slope and ground clearance for military forces The analysis of land assessment of the Avala test area included the definition of relief categories in relation to cover and concealment purposes with the aim to include the geomorphological basis

  4. Low Bone Density

    Science.gov (United States)

    ... Information › Bone Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your ... compared to people with normal bone density. Detecting Low Bone Density A bone density test will determine ...

  5. Snow cover and permafrost evolution in Siberia as simulated by the MGO regional climate model in the 20th and 21st centuries

    Science.gov (United States)

    Shkolnik, I. M.; Nadyozhina, E. D.; Pavlova, T. V.; Molkentin, E. K.; Semioshina, A. A.

    2010-01-01

    An approach to ground thermodynamics description using a coupled system of atmospheric regional climate and ground heat transfer models is improved by accounting for the time varying snow density. The simulations are compared to available observational analyses, and the sensitivity of the ground thermal regime to variable snow density is analysed. Projected changes of the ground thermal regime in the 21st century relative to the late 20th century are shown and compared to earlier estimates.

  6. Broadband Ground Motion Simulations for the Puente Hills Fault System

    Science.gov (United States)

    Graves, R. W.

    2005-12-01

    Recent geologic studies have identified the seismic potential of the Puente Hills fault system. This system is comprised of multiple blind thrust segments, a portion of which ruptured in the Mw 5.9 Whittier-Narrows earthquake. Rupture of the entire system could generate a Mw 7.2 (or larger) earthquake. To assess the potential hazard posed by the fault system, we have simulated the response for several earthquake scenarios. These simulations are unprecedented in scope and scale. Broadband (0-10 Hz) ground motions are computed at 66,000 sites, covering most of the LA metropolitan region. Low frequency (f 1 Hz) motions are calculated using a stochastic approach. We consider scenarios ranging from Mw 6.7 to Mw 7.2, including both high and low stress drop events. Finite-fault rupture models for these scenarios are generated following a wavenumber filtering technique (K-2 model) that has been calibrated against recent earthquakes. In all scenarios, strong rupture directivity channels large amplitude pulses of motion directly into the Los Angeles basin, which then propagate southward as basin surface waves. Typically, the waveforms near downtown Los Angeles are dominated by a strong, concentrated pulse of motion. At Long Beach (across the LA basin from the rupture) the waveforms are dominated by late arriving longer period surface waves. The great density of sites used in the calculation allows the construction of detailed maps of various ground motion parameters (PGA, PGV, SA), as well as full animations of the propagating broadband wave field. Additionally, the broadband time histories are available for use in non-linear response analyses of built structures.

  7. GRACAT, Software for grounding and collision analysis

    DEFF Research Database (Denmark)

    Friis-Hansen, Peter; Simonsen, Bo Cerup

    2002-01-01

    From 1998 to 2001 an integrated software package for grounding and collision analysis was developed at the Technical University of Denmark within the ISESO project at the cost of six man years (0.75M US$). The software provides a toolbox for a multitude of analyses related to collision and ground......From 1998 to 2001 an integrated software package for grounding and collision analysis was developed at the Technical University of Denmark within the ISESO project at the cost of six man years (0.75M US$). The software provides a toolbox for a multitude of analyses related to collision...... route where the result is the probability density functions for the cost of oil outflow in a given area per year for the two vessels. In this paper we describe the basic modelling principles and the capabilities of the software package. The software package can be downloaded for research purposes from...

  8. Cover stones on liquefiable soil bed under waves

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Hatipoglu, Figen; Fredsøe, Jørgen

    2010-01-01

    of stone layers (including the effect of an intermediate filter layer) were investigated. Pore pressure was measured across the soil depth. The experiments show that the soil liquefaction depended mainly on two parameters: the packing density of stones, and the number of stone layers. When the liquefaction...... occurs, stones sink in the soil. Mechanisms of liquefaction and sinking are described, and practical guidelines are recommended.......The paper describes the results of an experimental study on the behavior of cover stones on a liquefiable soil bed exposed to a progressive wave. The soil was silt with d50=0.098mm. Stones, the size of 4cm, were used as cover material. The effect of packing density of stones, and that of number...

  9. EM wave propagation analysis in plasma covered radar absorbing material

    CERN Document Server

    Singh, Hema; Rawat, Harish Singh

    2017-01-01

    This book focuses on EM propagation characteristics within multilayered plasma-dielectric-metallic media. The method used for analysis is impedance transformation method. Plasma covered radar absorbing material is approximated as a multi-layered dielectric medium. The plasma is considered to be bounded homogeneous/inhomogeneous medium. The reflection coefficient and hence return loss is analytically derived. The role of plasma parameters, such as electron density, collision frequency, plasma thickness, and plasma density profile in the absorption behavior of multi-layered plasma-RAM structure is described. This book provides a clearer picture of EM propagation within plasma. The reader will get an insight of plasma parameters that play significant role in deciding the absorption characteristics of plasma covered surfaces.

  10. Ground Enterprise Management System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Emergent Space Technologies Inc. proposes to develop the Ground Enterprise Management System (GEMS) for spacecraft ground systems. GEMS will provide situational...

  11. Influence of snow cover changes on surface radiation and heat balance based on the WRF model

    Science.gov (United States)

    Yu, Lingxue; Liu, Tingxiang; Bu, Kun; Yang, Jiuchun; Chang, Liping; Zhang, Shuwen

    2016-07-01

    The snow cover extent in mid-high latitude areas of the Northern Hemisphere has significantly declined corresponding to the global warming, especially since the 1970s. Snow-climate feedbacks play a critical role in regulating the global radiation balance and influencing surface heat flux exchange. However, the degree to which snow cover changes affect the radiation budget and energy balance on a regional scale and the difference between snow-climate and land use/cover change (LUCC)-climate feedbacks have been rarely studied. In this paper, we selected Heilongjiang Basin, where the snow cover has changed obviously, as our study area and used the WRF model to simulate the influences of snow cover changes on the surface radiation budget and heat balance. In the scenario simulation, the localized surface parameter data improved the accuracy by 10 % compared with the control group. The spatial and temporal analysis of the surface variables showed that the net surface radiation, sensible heat flux, Bowen ratio, temperature and percentage of snow cover were negatively correlated and that the ground heat flux and latent heat flux were positively correlated with the percentage of snow cover. The spatial analysis also showed that a significant relationship existed between the surface variables and land cover types, which was not obviously as that for snow cover changes. Finally, six typical study areas were selected to quantitatively analyse the influence of land cover types beneath the snow cover on heat absorption and transfer, which showed that when the land was snow covered, the conversion of forest to farmland can dramatically influence the net radiation and other surface variables, whereas the snow-free land showed significantly reduced influence. Furthermore, compared with typical land cover changes, e.g., the conversion of forest into farmland, the influence of snow cover changes on net radiation and sensible heat flux were 60 % higher than that of land cover changes

  12. Numerical Simulation of the Evolution of Snow Cover and Its Sensitivity Experiments

    Institute of Scientific and Technical Information of China (English)

    CHEN Haishan; SUN Zhaobo

    2005-01-01

    By using Comprehensive Land Surface Model (CLSM), three snow cases, i.e., France Col de Porte 1993/1994, 1994/1995 and BOREAS SSA-OJP 1994/1995, were simulated. The simulated results were compared with the observations to examine the capability of the model to describe the evolutions of snow cover under two different land cover conditions. Several sensitivity experiments were performed to investigate the effects of the parameterization schemes of some snow cover internal processes and vegetation on the model results. Results suggest that the CLSM simulates the basic processes of snow cover accurately and describes the features of snow cover evolutions reasonably, indicating that the model has the potential to model the processes related to the snow cover evolution. It is also found that the different parameterization schemes of the snowfall density and snow water holding capacity have significant effects on the simulation of snow cover. The estimation of snowfall density mainly impacts the simulated snow depth, and the underestimation (overestimation) of the snowfall density increases (decreases) the snow depth simulated significantly but with little effect on the simulated snow water equivalent (SWE). The parameterization of the snow water holding capacity plays a crucial role in the evolution of snow cover, especially in the ablation of snow cover. Larger snow water holding capacity usually leads to larger snow density and heat capacity by storing more liquid water in the snow layer, and makes the temperature of snow cover and the snow ablation vary more slowly.To a smaller snow water holding capacity, contrary is the case. The results also show that the physical processes related to the snow cover variation are different, which are dependent on the vegetation existed.Vegetation plays an important role in the evolution of soil-snow system by changing the energy balance at the snow-soil surface. The existence of vegetation is favorable to the maintenance of snow

  13. Structure and form of grounding lines of modern ice sheets

    Science.gov (United States)

    Tinto, K. J.; Bell, R. E.; Cochran, J. R.; Boghosian, A.; Porter, D. F.

    2015-12-01

    The form of the bed at the grounding line of a glacier and the character of the underlying rock can be critical to the stability of the glacier. Aerogravity measurements offer a unique insight in to the character of the grounding line environment. By combining depth measurements from further onshore radar and geological information from magnetic surveys, gravity-based models can reveal both the depth and slope of the bed at the grounding line. Where bed elevation is known at the grounding line, gravity models can show the density structure of the underlying rock. Operation IceBridge has flown coincident radar, lidar, photography, gravity and magnetic airborne surveys along fjords and over ice shelves in both Greenland and Antarctica. Aerogravity measurements have been used extensively to model the bathymetry of the sea floor in front of the grounding line, and to identify the depth of the grounding line in areas where radar measurements have proven challenging. These models have also been used to reveal the range of conditions at present day grounding lines, as well as those experienced in the past and predicted for future grounding line positions. In some regions, we have identified low-density sediment accumulations, at both present day grounding lines and within fjords, that we interpret to be terminal moraines deposited by the glacier itself during hiatuses in retreat. In other regions, we find that the present day grounding line is stalled on a ridge of high-density rock. Ridges such as these remain in the same position through many cycles of advance and retreat of the glacier. Our synthesis of gravity data from a wide range of glacial environments can be used to identify likely drivers of change at the grounding line, whether this is the depth, the slope, or the geological character of the glacier bed.

  14. Spatial Patterns of Snow Cover in North Carolina: Surface and Satellite Perspectives

    Science.gov (United States)

    Fuhrmann, Christopher M.; Hall, Dorothy K.; Perry, L. Baker; Riggs, George A.

    2010-01-01

    Snow mapping is a common practice in regions that receive large amounts of snowfall annually, have seasonally-continuous snow cover, and where snowmelt contributes significantly to the hydrologic cycle. Although higher elevations in the southern Appalachian Mountains average upwards of 100 inches of snow annually, much of the remainder of the Southeast U.S. receives comparatively little snowfall (snow cover and the physical processes that act to limit or improve its detection across the Southeast. In the present work, both in situ and remote sensing data are utilized to assess the spatial distribution of snow cover for a sample of recent snowfall events in North Carolina. Specifically, this work seeks to determine how well ground measurements characterize the fine-grained patterns of snow cover in relation to Moderate- Resolution Imaging Spectroradiometer (MODIS) snow cover products (in this case, the MODIS Fractional Snow Cover product).

  15. A global dataset of crowdsourced land cover and land use reference data.

    Science.gov (United States)

    Fritz, Steffen; See, Linda; Perger, Christoph; McCallum, Ian; Schill, Christian; Schepaschenko, Dmitry; Duerauer, Martina; Karner, Mathias; Dresel, Christopher; Laso-Bayas, Juan-Carlos; Lesiv, Myroslava; Moorthy, Inian; Salk, Carl F; Danylo, Olha; Sturn, Tobias; Albrecht, Franziska; You, Liangzhi; Kraxner, Florian; Obersteiner, Michael

    2017-06-13

    Global land cover is an essential climate variable and a key biophysical driver for earth system models. While remote sensing technology, particularly satellites, have played a key role in providing land cover datasets, large discrepancies have been noted among the available products. Global land use is typically more difficult to map and in many cases cannot be remotely sensed. In-situ or ground-based data and high resolution imagery are thus an important requirement for producing accurate land cover and land use datasets and this is precisely what is lacking. Here we describe the global land cover and land use reference data derived from the Geo-Wiki crowdsourcing platform via four campaigns. These global datasets provide information on human impact, land cover disagreement, wilderness and land cover and land use. Hence, they are relevant for the scientific community that requires reference data for global satellite-derived products, as well as those interested in monitoring global terrestrial ecosystems in general.

  16. Case study of a full-scale evapotranspiration cover

    Science.gov (United States)

    McGuire, P.E.; Andraski, B.J.; Archibald, R.E.

    2009-01-01

    The design, construction, and performance analyses of a 6.1 ha evapotranspiration (ET) landfill cover at the semiarid U.S. Army Fort Carson site, near Colorado Springs, Colo. are presented. Initial water-balance model simulations, using literature reported soil hydraulic data, aided selection of borrow-source soil type(s) that resulted in predictions of negligible annual drainage (???1 mm/year). Final construction design was based on refined water-balance simulations using laboratory determined soil hydraulic values from borrow area natural soil horizons that were described with USDA soil classification methods. Cover design components included a 122 cm thick clay loam (USDA), compaction ???80% of the standard Proctor maximum dry density (dry bulk density ???1.3 Mg/m3), erosion control measures, top soil amended with biosolids, and seeding with native grasses. Favorable hydrologic performance for a 5 year period was documented by lysimeter-measured and Richards'-based calculations of annual drainage that were all <0.4 mm/year. Water potential data suggest that ET removed water that infiltrated the cover and contributed to a persistent driving force for upward flow and removal of water from below the base of the cover. ?? 2009 ASCE.

  17. Ground- and excited-state impurity bands in quantum wells

    Science.gov (United States)

    Ghazali, A.; Gold, A.; Serre, J.

    1989-02-01

    The density of states and the spectral density of electrons in quantum wells with charged impurities are calculated with use of a multiple-scattering method. The impurity-density-dependent broadening and the gradual merging of the ground (1s) and excited (2p+/-,2s) impurity levels into impurity bands are investigated. At low density the shapes of the 1s, 2p+/-, and 2s spectral densities are found to be in excellent agreement with the analytical results obtained for the ideal two-dimensional Coulomb problem.

  18. The contribution of vegetation cover and bare soil to pixel reflectance in an arid ecosystem

    Science.gov (United States)

    Steele, C. M.; Smith, A.; Campanella, A.; Rango, A.

    2008-12-01

    The heterogeneity of vegetation and soils in arid and semi-arid environments complicates the analysis of medium spatial resolution remotely sensed imagery. A single pixel may contain several different types of vegetation, as well as a sizeable proportion of bare soil. We have used linear mixture modeling to explore the contribution of vegetation cover and bare soil to pixel reflectance. In October, 2006, aerial imagery (0.25 m spatial resolution) was acquired for our study sites in the Jornada Experimental Range, southern New Mexico. Imagery was also acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) for June and November, 2006. These data corresponded with pre- and post monsoon conditions. Object-based feature extraction was used to classify the aerial imagery to shrub, grass and bare ground cover classes. Percent cover was then calculated for each cover class. Visible-near-infrared and shortwave infrared ASTER reflectance data from both dates were combined into a single 18-band dataset (30 m spatial resolution). A vector overlay from the classification results of the aerial imagery was used to define pure endmember pixels in the ASTER imagery. Estimates of the proportions of shrub, grass and bare ground cover from the linear mixture modeling approach were compared with cover calculated using feature extraction from the aerial imagery. The results indicate that reflectance in ASTER pixels is likely to be a linear combination of the cover proportions of the three main cover types (shrubs, grass, bare ground). However, noticeable outliers in the relationship between cover calculated from each method, indicate there may be other variables that affect the accuracy with which we can estimate cover using linear mixture modeling.

  19. Connecting Brabant's cover sand landscapes through landscape history

    Science.gov (United States)

    Heskes, Erik; van den Ancker, Hanneke; Jungerius, Pieter Dirk; Harthoorn, Jaap; Maes, Bert; Leenders, Karel; de Jongh, Piet; Kluiving, Sjoerd; van den Oetelaar, Ger

    2015-04-01

    Noord-Brabant has the largest variety of cover sand landscapes in The Netherlands, and probably in Western Europe. During the Last Ice Age the area was not covered by land ice and a polar desert developed in which sand dunes buried the existing river landscapes. Some of these polar dune landscapes experienced a geomorphological and soil development that remained virtually untouched up to the present day, such as the low parabolic dunes of the Strabrechtse Heide or the later and higher dunes of the Oisterwijkse Vennen. As Noord-Brabant lies on the fringe of a tectonic basin, the thickness of cover sand deposits in the Centrale Slenk, part of a rift through Europe, amounts up to 20 metres. Cover sand deposits along the fault lines cause the special phenomenon of 'wijst' to develop, in which the higher grounds are wetter than the boarding lower grounds. Since 4000 BC humans settled in these cover sand landscapes and made use of its small-scale variety. An example are the prehistoric finds on the flanks and the historic towns on top of the 'donken' in northwest Noord-Brabant, where the cover sand landscapes are buried by river and marine deposits and only the peaks of the dunes protrude as donken. Or the church of Handel that is built beside a 'wijst' source and a site of pilgrimage since living memory. Or the 'essen' and plaggen agriculture that developed along the stream valleys of Noord-Brabant from 1300 AD onwards, giving rise to geomorphological features as 'randwallen' and plaggen soils of more than a metre thickness. Each region of Brabant each has its own approach in attracting tourists and has not yet used this common landscape history to connect, manage and promote their territories. We propose a landscape-historical approach to develop a national or European Geopark Brabants' cover sand landscapes, in which each region focuses on a specific part of the landscape history of Brabant, that stretches from the Late Weichselian polar desert when the dune

  20. Reinventing Grounded Theory: Some Questions about Theory, Ground and Discovery

    Science.gov (United States)

    Thomas, Gary; James, David

    2006-01-01

    Grounded theory's popularity persists after three decades of broad-ranging critique. In this article three problematic notions are discussed--"theory," "ground" and "discovery"--which linger in the continuing use and development of grounded theory procedures. It is argued that far from providing the epistemic security promised by grounded theory,…

  1. Impacts of Myanmar's Democratic Transition on its Land Cover Dynamics.

    Science.gov (United States)

    Biswas, S.

    2016-12-01

    Recently Myanmar transitioned from a closed economy, military government to market based economy and democracy. The impacts of the political and economic transition on its land cover can be described by characterizing the land cover dynamics during the transition period. Preliminary stratified sampling of forest conversions revealed that most changes from forest to non-forest are due to establishment of rubber plantations. Agricultural concessions are granted by the government to develop the agriculture sector and rubber is the most common plantation crop in Southern Myanmar. This study establishes a method to map and quantify the extent and age of rubber plantations in Thaton district of Myanmar using satellite remote sensing, GIS and ground data. The resultant rubber maps can be used to inform policy on land use planning, agriculture, forest and sustainable development.

  2. Five years of density matrix embedding theory

    CERN Document Server

    Wouters, Sebastian; Chan, Garnet K -L

    2016-01-01

    Density matrix embedding theory (DMET) describes finite fragments in the presence of a surrounding environment. In contrast to most embedding methods, DMET explicitly allows for quantum entanglement between both. In this chapter, we discuss both the ground-state and response theory formulations of DMET, and review several applications. In addition, a proof is given that the local density of states can be obtained by working with a Fock space of bath orbitals.

  3. The covering number of $M_{24}$

    Directory of Open Access Journals (Sweden)

    Michael Epstein

    2016-09-01

    Full Text Available A  finite cover $\\mathcal{C}$ of a group $G$ is a finite collection of proper subgroups of $G$ such that $G$ is equal to the union of all of the members of $\\mathcal{C}$. Such a cover is called {\\em minimal} if it has the smallest cardinality among all finite covers of $G$. The  covering number of $G$, denoted by $\\sigma(G$, is the number of subgroups in a minimal cover of $G$. In this paper the covering number of the Mathieu group $M_{24}$ is shown to be 3336.

  4. Ground water in Oklahoma

    Science.gov (United States)

    Leonard, A.R.

    1960-01-01

    One of the first requisites for the intelligent planning of utilization and control of water and for the administration of laws relating to its use is data on the quantity, quality, and mode of occurrence of the available supplies. The collection, evaluation and interpretation, and publication of such data are among the primary functions of the U.S. Geological Survey. Since 1895 the Congress has made appropriations to the Survey for investigation of the water resources of the Nation. In 1929 the Congress adopted the policy of dollar-for-dollar cooperation with the States and local governmental agencies in water-resources investigations of the U.S. Geological Survey. In 1937 a program of ground-water investigations was started in cooperation with the Oklahoma Geological Survey, and in 1949 this program was expanded to include cooperation with the Oklahoma Planning and Resources Board. In 1957 the State Legislature created the Oklahoma Water Resources Board as the principal State water agency and it became the principal local cooperator. The Ground Water Branch of the U.S. Geological Survey collects, analyzes, and evaluates basic information on ground-water resources and prepares interpretive reports based on those data. Cooperative ground-water work was first concentrated in the Panhandle counties. During World War II most work was related to problems of water supply for defense requirements. Since 1945 detailed investigations of ground-water availability have been made in 11 areas, chiefly in the western and central parts of the State. In addition, water levels in more than 300 wells are measured periodically, principally in the western half of the State. In Oklahoma current studies are directed toward determining the source, occurrence, and availability of ground water and toward estimating the quantity of water and rate of replenishment to specific areas and water-bearing formations. Ground water plays an important role in the economy of the State. It is

  5. Measurement of Crown Cover and Leaf Area Index Using Digital Cover Photography and Its Application to Remote Sensing

    Directory of Open Access Journals (Sweden)

    Craig Macfarlane

    2009-12-01

    Full Text Available Digital cover photography (DCP is a high resolution, vertical field-of-view method for ground-based estimation of forest metrics, and has advantages over fisheye sensors owing to its ease of application and high accuracy. We conducted the first thorough technical appraisal of DCP using both single-lens-reflex (DSLR and point-and-shoot cameras and concluded that differences result primarily from the better quality optics available for the DSLR camera. File compression, image size and ISO equivalence had little or no effect on estimates of forest metrics. We discuss the application of DCP for ground truthing of remotely sensed canopy metrics, and highlight its strengths over fisheye photography for testing and calibration of vertical field-of-view remote sensing.

  6. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  7. Detection of ground ice using ground penetrating radar method

    Institute of Scientific and Technical Information of China (English)

    Gennady M. Stoyanovich; Viktor V. Pupatenko; Yury A. Sukhobok

    2015-01-01

    The paper presents the results of a ground penetrating radar (GPR) application for the detection of ground ice. We com-bined a reflection traveltime curves analysis with a frequency spectrogram analysis. We found special anomalies at specific traces in the traveltime curves and ground boundaries analysis, and obtained a ground model for subsurface structure which allows the ground ice layer to be identified and delineated.

  8. Collison and Grounding

    DEFF Research Database (Denmark)

    Wang, G.; Ji, C.; Kuhala, P.;

    2006-01-01

    COMMITTEE MANDATE Concern for structural arrangements on ships and floating structures with regard to their integrity and adequacy in the events of collision and grounding, with the view towards risk assessment and management. Consideration shall be given to the frequency of occurrence, the proba......COMMITTEE MANDATE Concern for structural arrangements on ships and floating structures with regard to their integrity and adequacy in the events of collision and grounding, with the view towards risk assessment and management. Consideration shall be given to the frequency of occurrence...

  9. Recording ground motions where people live

    Science.gov (United States)

    Cranswick, E.; Gardner, B.; Hammond, S.; Banfill, R.

    The 1989 Loma Prieta, Calif., earthquake caused spectacular damage to structures up to 100 km away in the San Francisco Bay sedimentary basin, including the Cypress Street viaduct overpass, the Bay Bridge, and buildings in the San Francisco Marina district. Although the few mainshock ground motions recorded in the northern San Francisco Bay area were “significantly larger … than would be expected from the pre-existing data set,” none were recorded at the sites of these damaged structures [Hanks and Krawinkler, 1991].Loma Prieta aftershocks produced order-of-magnitude variations of ground motions related to sedimentary basin response over distances of 1-2 km and less [Cranswick et al., 1990]. In densely populated neighborhoods, these distances can encompass the residences of thousands of people, but it is very unlikely that these neighborhoods are monitored by even one seismograph. In the last decade, the complexity of computer models used to simulate high-frequency ground motions has increased by several orders of magnitude [e.g., Frankel and Vidale, 1992], but the number of seismograph stations—hence, the spatial density of the sampling of ground motion data—has remained relatively unchanged. Seismologists must therefore infer the nature of the ground motions in the great unknown regions between observation points.

  10. The value of snow cover

    Science.gov (United States)

    Sokratov, S. A.

    2009-04-01

    only and not even the main outcome from snow cover use. The value of snow cover for agriculture, water resources, industry and transportation is so naturally inside the activities that is not often quantified. However, any considerations of adaptation strategies for climate change with changing snow conditions need such quantification.

  11. Coding Issues in Grounded Theory

    Science.gov (United States)

    Moghaddam, Alireza

    2006-01-01

    This paper discusses grounded theory as one of the qualitative research designs. It describes how grounded theory generates from data. Three phases of grounded theory--open coding, axial coding, and selective coding--are discussed, along with some of the issues which are the source of debate among grounded theorists, especially between its…

  12. Coding Issues in Grounded Theory

    Science.gov (United States)

    Moghaddam, Alireza

    2006-01-01

    This paper discusses grounded theory as one of the qualitative research designs. It describes how grounded theory generates from data. Three phases of grounded theory--open coding, axial coding, and selective coding--are discussed, along with some of the issues which are the source of debate among grounded theorists, especially between its…

  13. Recharge estimation for transient ground water modeling.

    Science.gov (United States)

    Jyrkama, Mikko I; Sykes, Jon F; Normani, Stefano D

    2002-01-01

    Reliable ground water models require both an accurate physical representation of the system and appropriate boundary conditions. While physical attributes are generally considered static, boundary conditions, such as ground water recharge rates, can be highly variable in both space and time. A practical methodology incorporating the hydrologic model HELP3 in conjunction with a geographic information system was developed to generate a physically based and highly detailed recharge boundary condition for ground water modeling. The approach uses daily precipitation and temperature records in addition to land use/land cover and soils data. The importance of the method in transient ground water modeling is demonstrated by applying it to a MODFLOW modeling study in New Jersey. In addition to improved model calibration, the results from the study clearly indicate the importance of using a physically based and highly detailed recharge boundary condition in ground water quality modeling, where the detailed knowledge of the evolution of the ground water flowpaths is imperative. The simulated water table is within 0.5 m of the observed values using the method, while the water levels can differ by as much as 2 m using uniform recharge conditions. The results also show that the combination of temperature and precipitation plays an important role in the amount and timing of recharge in cooler climates. A sensitivity analysis further reveals that increasing the leaf area index, the evaporative zone depth, or the curve number in the model will result in decreased recharge rates over time, with the curve number having the greatest impact.

  14. Illumination compensation in ground based hyperspectral imaging

    Science.gov (United States)

    Wendel, Alexander; Underwood, James

    2017-07-01

    Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

  15. National Land Cover Database: 1986-1993

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — NLCD 92 (National Land Cover Dataset 1992) is a 21-category land cover classification scheme that has been applied consistently over the conterminous U.S. It is...

  16. 1990 Kansas Land Cover Patterns Update

    Data.gov (United States)

    Kansas Data Access and Support Center — In 2008, an update of the 1990 Kansas Land Cover Patterns (KLCP) database was undertaken. The 1990 KLCP database depicts 10 general land cover classes for the State...

  17. VT National Land Cover Dataset - 2001

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The NLCD2001 layer available from VCGI is a subset of the the National Land Cover Database 2001 land cover layer for mapping zone 65 was produced...

  18. National Land Cover Database: 1986-1993

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — NLCD 92 (National Land Cover Dataset 1992) is a 21-category land cover classification scheme that has been applied consistently over the conterminous U.S. It is...

  19. A Citizen's Guide to Evapotranspiration Covers

    Science.gov (United States)

    This guide explains Evapotranspiration Covers which are Evapotranspiration (ET) covers are a type of cap placed over contaminated material, such as soil, landfill waste, or mining tailings, to prevent water from reaching it.

  20. Watershed impervious cover relative to stream location

    Data.gov (United States)

    U.S. Environmental Protection Agency — Estimates of watershed (12-digit huc) impervious cover and impervious cover near streams and water body shorelines for three dates (2001, 2006, 2011) using NLCD...

  1. Grounding and shielding circuits and interference

    CERN Document Server

    Morrison, Ralph

    2016-01-01

    Applies basic field behavior in circuit design and demonstrates how it relates to grounding and shielding requirements and techniques in circuit design This book connects the fundamentals of electromagnetic theory to the problems of interference in all types of electronic design. The text covers power distribution in facilities, mixing of analog and digital circuitry, circuit board layout at high clock rates, and meeting radiation and susceptibility standards. The author examines the grounding and shielding requirements and techniques in circuit design and applies basic physics to circuit behavior. The sixth edition of this book has been updated with new material added throughout the chapters where appropriate. The presentation of the book has also been rearranged in order to reflect the current trends in the field.

  2. Thermodestruction of components of anticorrosion polymer cover

    OpenAIRE

    Тихомирова, Татьяна Сергеевна

    2012-01-01

    This article concerns the processes of thermodestruction of multilayer polymer cover, which is widely used to protect the external surface of steel pipelines. The main purpose of the work is to prove the possibility of combination of various polymer components in one cover preserving the thermostability of the cover. The behavior of the separate modified components of the cover at high temperatures was analyzed using the differential-thermal analysis and the derivative thermogravimetry...

  3. [Snow cover pollution monitoring in Ufa].

    Science.gov (United States)

    Daukaev, R A; Suleĭmanov, R A

    2008-01-01

    The paper presents the results of examining the snow cover polluted with heavy metals in the large industrial town of Ufa. The level of man-caused burden on the snow cover of the conventional parts of the town was estimated and compared upon exposure to a wide range of snow cover pollutants. The priority snow cover pollutants were identified among the test heavy metals.

  4. Mechanics of Ship Grounding

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1996-01-01

    In these notes first a simplified mathematical model is presented for analysis of ship hull loading due to grounding on relatively hard and plane sand, clay or rock sea bottoms. In a second section a more rational calculation model is described for the sea bed soil reaction forces on the sea bottom...

  5. Grounding Anger Management

    Directory of Open Access Journals (Sweden)

    Odis E. Simmons, PhD

    2017-06-01

    Full Text Available One of the things that drew me to grounded theory from the beginning was Glaser and Strauss’ assertion in The Discovery of Grounded Theory that it was useful as a “theoretical foothold” for practical applications (p. 268. From this, when I was a Ph.D student studying under Glaser and Strauss in the early 1970s, I devised a GT based approach to action I later came to call “grounded action.” In this short paper I’ll present a very brief sketch of an anger management program I developed in 1992, using grounded action. I began my research by attending a two-day anger management training workshop designed for training professionals in the most commonly used anger management model. Like other intervention programs I had seen, this model took a psychologizing and pathologizing approach to the issue. Following this, I sat through the full course of an anger management program that used this model, observing the reactions of the participants and the approach of the facilitator. Following each session I conducted open-ended interviews with most of the participants, either individually or in groups of two or three. I had also done previous research in counseling and social work contexts that turned out to be very relevant to an anger management program design.

  6. Grounding in Instant Messaging

    Science.gov (United States)

    Fox Tree, Jean E.; Mayer, Sarah A.; Betts, Teresa E.

    2011-01-01

    In two experiments, we investigated predictions of the "collaborative theory of language use" (Clark, 1996) as applied to instant messaging (IM). This theory describes how the presence and absence of different grounding constraints causes people to interact differently across different communicative media (Clark & Brennan, 1991). In Study 1, we…

  7. Informed Grounded Theory

    Science.gov (United States)

    Thornberg, Robert

    2012-01-01

    There is a widespread idea that in grounded theory (GT) research, the researcher has to delay the literature review until the end of the analysis to avoid contamination--a dictum that might turn educational researchers away from GT. Nevertheless, in this article the author (a) problematizes the dictum of delaying a literature review in classic…

  8. TARDEC Ground Vehicle Robotics

    Science.gov (United States)

    2013-05-30

    UNCLASSIFIED UNCLASSIFIED 10 Optionally Manned Vehicles OMV can be driven by a soldier; OMV can drive a soldier; OMV can be remotely operated; OMV can be...all missions for OMV (i.e. shared driving) (i.e. remotely operated) 2 m od al iti es Mission Payloads UNCLASSIFIED UNCLASSIFIED 11 Ground

  9. Estimating mean plant cover from different types of cover data: a coherent statistical framework

    National Research Council Canada - National Science Library

    Damgaard, C

    2014-01-01

    Plant cover is measured by different methods and it is important to be able to estimate mean cover and to compare estimates of plant cover across different sampling methods in a coherent statistical framework...

  10. Managing cover crops: an economic perspective

    Science.gov (United States)

    Common reasons given by producers as to why they do not adopt cover crops are related to economics: time, labor, and cost required for planting and managing cover crops. While many of the agronomic benefits of cover crops directly relate to economics, there are costs associated with adopting the pra...

  11. Reducibility of Covers of AFT shifts

    DEFF Research Database (Denmark)

    Bates, Teresa; Eilers, Søren; Pask, David

    2011-01-01

    In this paper we show that the reducibility structure of several covers of sofic shifts is a flow invariant. In addition, we prove that for an irreducible subshift of almost finite type the left Krieger cover and the past set cover are reducible. We provide an example which shows that there are n...

  12. National land-cover pattern data

    Science.gov (United States)

    Kurt H. Riitters; James D. Wickham; James E. Vogelmann; K. Bruce Jones

    2000-01-01

    Land cover and its spatial patterns are key ingredients in ecological studies that consider large regions and the impacts of human activities. Because humanity is a principal driver of land-cover change over large regions (Turner et al. 1990), land-cover data provide direct measures of human activity, and both direct and indirect measures of ecological conditions...

  13. 49 CFR 193.2167 - Covered systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Covered systems. 193.2167 Section 193.2167...: FEDERAL SAFETY STANDARDS Design Impoundment Design and Capacity § 193.2167 Covered systems. A covered impounding system is prohibited except for concrete wall designed tanks where the concrete wall is an outer...

  14. Density functional theory with quantum nuclei

    CERN Document Server

    Requist, Ryan

    2016-01-01

    It is proved that the ground state energy of an electron-nuclear system is a variational functional of the conditional electronic density n_R(r), the nuclear wavefunction \\chi(R) and the quantum geometric tensor of the conditional electronic wavefunction $T_{\\mu\

  15. Soil moisture characterization of the Valencia anchor station. Ground, aircraft measurements and simulations

    DEFF Research Database (Denmark)

    Lopez-Baeza, E; Antolin, M C; Balling, Jan E.

    2009-01-01

    , soil type, lithology, geology, elevation, slope and vegetation cover conditions. Complementary to the ground measurements, flight operations were performed over this control area using the Helsinki University of Technology TKK Short Skyvan research aircraft which contained onboard a payload constituted...

  16. Installation and Assembly, Electrical Ground Support Equipment (GSE), Specification for

    Science.gov (United States)

    Denson, Erik C.

    2014-01-01

    This specification covers the general workmanship requirements and procedures for the complete installation and assembly of electrical ground support equipment (EGSE) such as terminal distributors, junction boxes, conduit and fittings, cable trays and accessories, interconnecting cables (including routing requirements), motor-control equipment, and necessary hardware as specified by the applicable contract and drawings.

  17. The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens.

    Science.gov (United States)

    Bakker, Matthew G; Acharya, Jyotsna; Moorman, Thomas B; Robertson, Alison E; Kaspar, Thomas C

    2016-06-01

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping.

  18. Estimating Hedonic Price Indices for Ground Vehicles

    Science.gov (United States)

    2015-06-01

    organizations use price indices to distinguish sector-specific real price growth from general inflation  OMB uses price indices to estimate the relative...I N S T I T U T E F O R D E F E N S E A N A L Y S E S Estimating Hedonic Price Indices for Ground Vehicles (Presentation) David M. Tate Stanley...currently valid OMB control number. 1. REPORT DATE JUN 2015 2. REPORT TYPE 3. DATES COVERED 4. TITLE AND SUBTITLE Estimating Hedonic Price

  19. Isogeometric shape optimization of magnetic density separators

    OpenAIRE

    2013-01-01

    Purpose: The waste recycling industry increasingly relies on magnetic density separators. These devices generate an upward magnetic force in ferro-fluids allowing to separate the immersed particles according to their mass density. Recently a new separator design that significantly reduces the required amount of permanent magnet material has been proposed. The purpose of this paper is to alleviate the undesired end-effects in this design by altering the shape of the ferromagnetic covers of the...

  20. Chemical characteristics and global density of an eutroferric red latosol cultivated with cover crops in Toledo District, Parana StateCaracterísticas químicas e densidade global de um latossolo vermelho eutróferrico cultivado com plantas de cobertura em Toledo-PR

    Directory of Open Access Journals (Sweden)

    Maicon Vendrúscolo

    2010-02-01

    Full Text Available The expansion of agricultural frontier through deforestation, adoption of mechanization and intensive use of inappropriate management practices, has promoted changes in the physical, chemical and biological properties of the soil, resulting in degradation processes, thus reducing productivity. Based on this, the objective the work was to evaluate the chemical characteristics and the global density of an Eutroferric Red Latosol of the experimental area of the Parana Catholic University, Toledo Campus. The experimental design used was casualized blocks with four replicates, in which the treatments were: millet, hairy vetch and control (spontaneous vegetation. The evaluations were: dry mass production, with the highest amount for millet (7.07 Mg ha¹, global soil density in which the lowest value was under control and the highest in hairy vetch; density of weeds population in which the control treatment had the highest value on; soil chemical characteristics, in which both hairy vetch and millet presented higher results compared to the control, being different in some nutrients, such as phosphorus, potassium and nitrogen.A expansão da fronteira agrícola através de desmatamentos, adoção de mecanização intensiva e uso de práticas de manejo inadequadas, tem promovido alterações nas propriedades físicas, químicas e biológicas do solo, resultando em processos de degradação, reduzindo desta maneira a produtividade. Com base no exposto, o objetivo do trabalho foi avaliar características químicas e densidade global de um Latossolo Vermelho Eutróferrico, da área experimental da Fazenda da Pontifícia Universidade Católica do Paraná, Campus Toledo, sob tratamentos do milheto (Pennisetum glaucum e da ervilhaca peluda (Vicia villosa como plantas de cobertura. O delineamento utilizado foi o de blocos ao acaso com quatro repetições, em que os tratamentos foram: milheto, ervilhaca peluda e testemunha (vegetação espontânea. As avalia

  1. Above-ground biomass and structure of pristine Siberian Scots pine forests as controlled by competition and fire.

    Science.gov (United States)

    Wirth, C; Schulze, E-D; Schulze, W; von Stünzner-Karbe, D; Ziegler, W; Miljukova, I M; Sogatchev, A; Varlagin, A B; Panvyorov, M; Grigoriev, S; Kusnetzova, W; Siry, M; Hardes, G; Zimmermann, R; Vygodskaya, N N

    1999-10-01

    The study presents a data set of above-ground biomass (AGB), structure, spacing and fire regime, for 24 stands of pristine Siberian Scots pine (Pinus sylvestris) forests with lichens (n = 20) or Vaccinium/mosses (n = 4) as ground cover, along four chronosequences. The stands of the "lichen" site type (LT) were stratified into three chronosequences according to stand density and fire history. Allometric equations were established from 90 sample trees for stem, coarse branch, fine branch, twig and needle biomass. The LT stands exhibited a low but sustained biomass accumulation until a stand age of 383 years. AGB reached only 6-10 kgdw m(-2) after 200 years depending on stand density and fire history compared to 20 kgdw m(-2) in the "Vaccinium" type (VT) stands. Leaf area index (LAI) in the LT stands remained at 0.5-1.5 and crown cover was 30-60%, whereas LAI reached 2.5 and crown cover was >100% in the VT stands. Although nearest-neighbour analyses suggested the existence of density-dependent mortality, fire impact turned out to have a much stronger effect on density dynamics. Fire scar dating and calculation of mean and initial fire return intervals revealed that within the LT stands differences in structure and biomass were related to the severity of fire regimes, which in turn was related to the degree of landscape fragmentation by wetlands. Self-thinning analysis was used to define the local carrying capacity for biomass. A series of undisturbed LT stands was used to characterise the upper self-thinning boundary. Stands that had experienced a moderate fire regime were positioned well below the self-thinning boundary in a distinct fire-thinning band of reduced major axis regression slope -0.26. We discuss how this downward shift resulted from alternating phases of density reduction by fire and subsequent regrowth. We conclude that biomass in Siberian Scots pine forests is strongly influenced by fire and that climate change will affect ecosystem

  2. Preliminary results of mapping urban land cover with Seasat SAR imagery

    Science.gov (United States)

    Henderson, F. M.; Wharton, S. W.; Toll, D. L.

    1980-01-01

    The detectability of urban land cover types is explored using digitally processed Seasat SAR imagery of the Denver, Colorado area. Test sites within the metropolitan area were selected to include a cross section of Anderson, et. al. Level II land cover classes and cover types representative of the urban area growth stages. Using the Image 100 interactive processing system each test site was level sliced in an attempt to define specific reflectance boundaries for each cover type and to determine the spectral and spatial characteristics of homogeneous response regions. The rural-urban fringe boundary was readily definable, but a precise Level I and Level II land cover classification was not possible. High density housing could be separated from low density housing and from parks, but reflectance values were often look angle dependent. Confusion between some water and vegetation responses also posed problems.

  3. Superhydrophilicity of a nanofiber-covered aluminum surface fabricated via pyrophosphoric acid anodizing

    Science.gov (United States)

    Nakajima, Daiki; Kikuchi, Tatsuya; Natsui, Shungo; Suzuki, Ryosuke O.

    2016-12-01

    A superhydrophilic aluminum surface covered by numerous alumina nanofibers was fabricated via pyrophosphoric acid anodizing. High-density anodic alumina nanofibers grow on the bottom of a honeycomb oxide via anodizing in concentrated pyrophosphoric acid. The water contact angle on the nanofiber-covered aluminum surface decreased with time after a 4 μL droplet was placed on the surface, and a superhydrophilic behavior with a contact angle measuring 2.2° was observed within 2 s; this contact angle is considerably lower than those observed for electropolished and porous alumina-covered aluminum surfaces. There was no dependence of the superhydrophilicity on the density of alumina nanofibers fabricated via different constant voltage anodizing conditions. The superhydrophilic property of the surface covered by anodic alumina nanofibers was maintained during an exposure test for 359 h. The quick-drying and snow-sliding behaviors of the superhydrophilic aluminum covered with anodic alumina nanofibers were demonstrated.

  4. Thermodynamic ground states of platinum metal nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Aberg, D; Sadigh, B; Crowhurst, J; Goncharov, A

    2007-10-09

    We have systematically studied the thermodynamic stabilities of various phases of the nitrides of the platinum metal elements using density functional theory. We show that for the nitrides of Rh, Pd, Ir and Pt two new crystal structures, in which the metal ions occupy simple tetragonal lattice sites, have lower formation enthalpies at ambient conditions than any previously proposed structures. The region of stability can extend up to 17 GPa for PtN{sub 2}. Furthermore, we show that according to calculations using the local density approximation, these new compounds are also thermodynamically stable at ambient pressure and thus may be the ground state phases for these materials. We further discuss the fact that the local density and generalized gradient approximations predict different values of the absolute formation enthalpies as well different relative stabilities between simple tetragonal and the pyrite or marcasite structures.

  5. Ant community change across a ground vegetation gradient in north Florida's longleaf pine flatwoods

    OpenAIRE

    David Lubertazzi; Walter Tschinkel

    2003-01-01

    Ant communities in longleaf pine habitats are poorly known and hence the naturally occurring ant assemblages of a large portion of southeastern North America are not well understood. This study examined the diverse ant community found in the longleaf pine flatwoods of north Florida and tested how ant diversity changes along a herbaceous ground cover gradient. Restoring the ground cover to its original floral composition is an important focus of longleaf pine conservation and hence it is impor...

  6. Language grounding in robots

    CERN Document Server

    2012-01-01

    Covers all aspects of language interaction with robots, from embodiment, action and perception to conceptualization and grammar in a single volume Discusses several significant innovations, such as robotic embodiment, evolutionary derivation of neural controllers, embodied cognitive semantics and fluid construction grammar Presents the new humanoid robot platform, Myon, used by an increasing number of research laboratories

  7. Infrasonic induced ground motions

    Science.gov (United States)

    Lin, Ting-Li

    On January 28, 2004, the CERI seismic network recorded seismic signals generated by an unknown source. Our conclusion is that the acoustic waves were initiated by an explosive source near the ground surface. The meteorological temperature and effective sound speed profiles suggested existence of an efficient near-surface waveguide that allowed the acoustic disturbance to propagate to large distances. An explosion occurring in an area of forest and farms would have limited the number of eyewitnesses. Resolution of the source might be possible by experiment or by detailed analysis of the ground motion data. A seismo-acoustic array was built to investigate thunder-induced ground motions. Two thunder events with similar N-wave waveforms but different horizontal slownesses are chosen to evaluate the credibility of using thunder as a seismic source. These impulsive acoustic waves excited P and S reverberations in the near surface that depend on both the incident wave horizontal slowness and the velocity structure in the upper 30 meters. Nineteen thunder events were chosen to further investigate the seismo-acoustic coupling. The consistent incident slowness differences between acoustic pressure and ground motions suggest that ground reverberations were first initiated somewhat away from the array. Acoustic and seismic signals were used to generate the time-domain transfer function through the deconvolution technique. Possible non-linear interaction for acoustic propagation into the soil at the surface was observed. The reverse radial initial motions suggest a low Poisson's ratio for the near-surface layer. The acoustic-to-seismic transfer functions show a consistent reverberation series of the Rayleigh wave type, which has a systematic dispersion relation to incident slownesses inferred from the seismic ground velocity. Air-coupled Rayleigh wave dispersion was used to quantitatively constrain the near-surface site structure with constraints afforded by near-surface body

  8. Changes of snow cover in Poland

    Science.gov (United States)

    Szwed, Małgorzata; Pińskwar, Iwona; Kundzewicz, Zbigniew W.; Graczyk, Dariusz; Mezghani, Abdelkader

    2017-02-01

    The present paper examines variability of characteristics of snow cover (snow cover depth, number of days with snow cover and dates of beginning and end of snow cover) in Poland. The study makes use of a set of 43 long time series of observation records from the stations in Poland, from 1952 to 2013. To describe temporal changes in snow cover characteristics, the intervals of 1952-1990 and of 1991-2013 are compared and trends in analysed data are sought (e.g., using the Mann-Kendall test). Observed behaviour of time series of snow-related variables is complex and not easy to interpret, for instance because of the location of the research area in the zone of transitional moderate climate, where strong variability of climate events is one of the main attributes. A statistical link between the North Atlantic Oscillation (NAO) index and the snow cover depth, as well as the number of snow cover days is found.

  9. Environmental Controls on Above-Ground Biomass in the Taita Hills, Kenya

    Science.gov (United States)

    Adhikari, H.; Heiskanen, J.; Siljander, M.; Maeda, E. E.; Heikinheimo, V.; Pellikka, P.

    2016-12-01

    Tropical forests are globally significant ecosystems which maintain high biodiversity and provide valuable ecosystem services, including carbon sink, climate change mitigation and adaptation. This ecosystem has been severely degraded for decades. However, the magnitude and spatial patterns of the above ground biomass (AGB) in the tropical forest-agriculture landscapes is highly variable, even under the same climatic condition and land use. This work aims 1) to generate wall-to-wall map of AGB density for the Taita Hills in Kenya based on field measurements and airborne laser scanning (ALS) and 2) to examine environmental controls on AGB using geospatial data sets on topography, soils, climate and land use, and statistical modelling. The study area (67000 ha) is located in the northernmost part of the Eastern Arc Mountains of Kenya and Tanzania, and the highest hilltops reach over 2200 m in elevation. Most of the forest area has been cleared for croplands and agroforestry, and hills are surrounded by the semi-arid scrublands and dry savannah at an elevation of 600-900 m a.s.l. As a result, the current land cover is a mosaic of various types of land cover and land use. The field measurements were carried out in total of 216 plots in 2013-2015 for AGB computations and ALS flights were conducted in 2014-2015. AGB map at 30 m x 30 m resolution was implemented using multiple linear regression based on ALS variables derived from the point cloud, namely canopy cover and 25 percentile height of ALS returns (R2 = 0.88). Boosted regression trees (BRT) was used for examining the relationship between AGB and explanatory variables, which were derived from ALS-based high resolution DEM (2 m resolution), soil database, downscaled climate data and land cover/use maps based on satellite image analysis. The results of these analyses will be presented in the conference.

  10. Decentralized Ground Staff Scheduling

    DEFF Research Database (Denmark)

    Sørensen, M. D.; Clausen, Jens

    2002-01-01

    Typically, ground staff scheduling is centrally planned for each terminal in an airport. The advantage of this is that the staff is efficiently utilized, but a disadvantage is that staff spends considerable time walking between stands. In this paper a decentralized approach for ground staff...... scheduling is investigated. The airport terminal is divided into zones, where each zone consists of a set of stands geographically next to each other. Staff is assigned to work in only one zone and the staff scheduling is planned decentralized for each zone. The advantage of this approach is that the staff...... work in a smaller area of the terminal and thus spends less time walking between stands. When planning decentralized the allocation of stands to flights influences the staff scheduling since the workload in a zone depends on which flights are allocated to stands in the zone. Hence solving the problem...

  11. Ibis ground calibration

    Energy Technology Data Exchange (ETDEWEB)

    Bird, A.J.; Barlow, E.J.; Tikkanen, T. [Southampton Univ., School of Physics and Astronomy (United Kingdom); Bazzano, A.; Del Santo, M.; Ubertini, P. [Istituto di Astrofisica Spaziale e Fisica Cosmica - IASF/CNR, Roma (Italy); Blondel, C.; Laurent, P.; Lebrun, F. [CEA Saclay - Sap, 91 - Gif sur Yvette (France); Di Cocco, G.; Malaguti, E. [Istituto di Astrofisica Spaziale e Fisica-Bologna - IASF/CNR (Italy); Gabriele, M.; La Rosa, G.; Segreto, A. [Istituto di Astrofisica Spaziale e Fisica- IASF/CNR, Palermo (Italy); Quadrini, E. [Istituto di Astrofisica Spaziale e Fisica-Cosmica, EASF/CNR, Milano (Italy); Volkmer, R. [Institut fur Astronomie und Astrophysik, Tubingen (Germany)

    2003-11-01

    We present an overview of results obtained from IBIS ground calibrations. The spectral and spatial characteristics of the detector planes and surrounding passive materials have been determined through a series of calibration campaigns. Measurements of pixel gain, energy resolution, detection uniformity, efficiency and imaging capability are presented. The key results obtained from the ground calibration have been: - optimization of the instrument tunable parameters, - determination of energy linearity for all detection modes, - determination of energy resolution as a function of energy through the range 20 keV - 3 MeV, - demonstration of imaging capability in each mode, - measurement of intrinsic detector non-uniformity and understanding of the effects of passive materials surrounding the detector plane, and - discovery (and closure) of various leakage paths through the passive shielding system.

  12. Effect of rock fragment embedding on the aeolian deposition of dust on stone-covered surfaces

    NARCIS (Netherlands)

    Goossens, D.

    2005-01-01

    Many stone-covered surfaces on Earth are subject to aeolian deposition of atmospheric dust. This study investigates how the deposition of dust is affected when rock fragments become gradually more embedded in the ground or, inversely, become more concentrated on the surface. Experiments were execute

  13. Woody vegetation and land cover changes in the Sahel of Mali (1967–2011)

    DEFF Research Database (Denmark)

    Spiekermann, Raphael; Brandt, Martin; Samimi, Cyrus

    2014-01-01

    In the past 50 years, the Sahel has experienced significant tree- and land cover changes accelerated by human expansion and prolonged droughts during the 1970s and 1980s. This study uses remote sensing techniques, supplemented by ground-truth data to compare pre-drought woody vegetation and land...

  14. Spatial predictions of cover attributes of rangeland ecosystems using regression kriging and remote sensing

    Science.gov (United States)

    Sound rangeland management requires accurate information on rangeland condition over large landscapes. A commonly-applied approach to making spatial predictions of attributes related to rangeland condition (e.g., shrub or bare ground cover) from remote sensing is via regression between field and rem...

  15. Mechanics of Ship Grounding

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1996-01-01

    In these notes first a simplified mathematical model is presented for analysis of ship hull loading due to grounding on relatively hard and plane sand, clay or rock sea bottoms. In a second section a more rational calculation model is described for the sea bed soil reaction forces on the sea bottom....... Finally, overall hull failure is considered first applying a quasistatic analysis model and thereafter a full dynamic model....

  16. Effect of winter cover crops on nematode population levels in north Florida.

    Science.gov (United States)

    Wang, K-H; McSorley, R; Gallaher, R N

    2004-12-01

    Two experiments were conducted in north-central Florida to examine the effects of various winter cover crops on plant-parasitic nematode populations through time. In the first experiment, six winter cover crops were rotated with summer corn (Zea mays), arranged in a randomized complete block design. The cover crops evaluated were wheat (Triticum aestivum), rye (Secale cereale), oat (Avena sativa), lupine (Lupinus angustifolius), hairy vetch (Vicia villosa), and crimson clover (Trifolium incarnatum). At the end of the corn crop in year 1, population densities of Meloidogyne incognita were lowest on corn following rye or oat (P cover crops: soybean (Glycine max), cowpea (Vigna unguiculata), sorghum-sudangrass (Sorghum bicolor x S. sudanense), sunn hemp (Crotalaria juncea), and corn. Population densities of M. incognita and Helicotylenchus dihystera were affected by previous tropical cover crops (P winter cover crops present at the time of sampling. Plots planted to sunn hemp in the fall maintained the lowest M. incognita and H. dihystera numbers. Results suggest that winter cover crops tested did not suppress plant-parasitic nematodes effectively. Planting tropical cover crops such as sunn hemp after corn in a triple-cropping system with winter cover crops may provide more versatile nematode management strategies in northern Florida.

  17. Outdoor ground impedance models.

    Science.gov (United States)

    Attenborough, Keith; Bashir, Imran; Taherzadeh, Shahram

    2011-05-01

    Many models for the acoustical properties of rigid-porous media require knowledge of parameter values that are not available for outdoor ground surfaces. The relationship used between tortuosity and porosity for stacked spheres results in five characteristic impedance models that require not more than two adjustable parameters. These models and hard-backed-layer versions are considered further through numerical fitting of 42 short range level difference spectra measured over various ground surfaces. For all but eight sites, slit-pore, phenomenological and variable porosity models yield lower fitting errors than those given by the widely used one-parameter semi-empirical model. Data for 12 of 26 grassland sites and for three beech wood sites are fitted better by hard-backed-layer models. Parameter values obtained by fitting slit-pore and phenomenological models to data for relatively low flow resistivity grounds, such as forest floors, porous asphalt, and gravel, are consistent with values that have been obtained non-acoustically. Three impedance models yield reasonable fits to a narrow band excess attenuation spectrum measured at short range over railway ballast but, if extended reaction is taken into account, the hard-backed-layer version of the slit-pore model gives the most reasonable parameter values.

  18. Assessing Hydrologic Impacts of Future Land Cover Change ...

    Science.gov (United States)

    Long‐term land‐use and land cover change and their associated impacts pose critical challenges to sustaining vital hydrological ecosystem services for future generations. In this study, a methodology was developed on the San Pedro River Basin to characterize hydrologic impacts from future urban growth through time. This methodology was then expanded and utilized to characterize the changing hydrology on the South Platte River Basin. Future urban growth is represented by housingdensity maps generated in decadal intervals from 2010 to 2100, produced by the U.S. Environmental Protection Agency (EPA) Integrated Climate and Land‐Use Scenarios (ICLUS) project. ICLUS developed future housing density maps by adapting the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) social, economic, and demographic storylines to the conterminous United States. To characterize hydrologic impacts from future growth, the housing density maps were reclassified to National Land Cover Database (NLCD) 2006 land cover classes and used to parameterize the Soil and Water Assessment Tool (SWAT) using the Automated Geospatial Watershed Assessment (AGWA) tool. The objectives of this project were to 1) develop and describe a methodology for adapting the ICLUS data for use in AGWA as anapproach to evaluate basin‐wide impacts of development on water‐quantity and ‐quality, 2) present initial results from the application of the methodology to

  19. Assessing Hydrologic Impacts of Future Land Cover Change ...

    Science.gov (United States)

    Long‐term land‐use and land cover change and their associated impacts pose critical challenges to sustaining vital hydrological ecosystem services for future generations. In this study, a methodology was developed on the San Pedro River Basin to characterize hydrologic impacts from future urban growth through time. This methodology was then expanded and utilized to characterize the changing hydrology on the South Platte River Basin. Future urban growth is represented by housingdensity maps generated in decadal intervals from 2010 to 2100, produced by the U.S. Environmental Protection Agency (EPA) Integrated Climate and Land‐Use Scenarios (ICLUS) project. ICLUS developed future housing density maps by adapting the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) social, economic, and demographic storylines to the conterminous United States. To characterize hydrologic impacts from future growth, the housing density maps were reclassified to National Land Cover Database (NLCD) 2006 land cover classes and used to parameterize the Soil and Water Assessment Tool (SWAT) using the Automated Geospatial Watershed Assessment (AGWA) tool. The objectives of this project were to 1) develop and describe a methodology for adapting the ICLUS data for use in AGWA as anapproach to evaluate basin‐wide impacts of development on water‐quantity and ‐quality, 2) present initial results from the application of the methodology to

  20. Chapter 6: Tree-compatible ground covers for reforestation and erosion control

    Science.gov (United States)

    J. Burger; V. Davis; C. Zipper; J. Skousen; C. Barton; P. Angel

    2017-01-01

    Productive native forests create economic value for landowners, produce raw materials for wood-based products, and provide benefits such as watershed control, water quality protection, carbon storage, wildlife habitat, and native plant diversity. Owners of lands mined for coal in the Appalachian region are increasingly interested in assuring that productive forests are...