WorldWideScience

Sample records for ground cover electronic

  1. 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.

  2. 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%.

  3. 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...

  4. Electronic Ground State of Higher Acenes

    CERN Document Server

    Jiang, De-en

    2007-01-01

    We examine the electronic ground state of acenes with different number of fused benzene rings (up to 40) by using first principles density functional theory. Their properties are compared with those of infinite polyacene. We find that the ground state of acenes that consist of more than seven fused benzene rings is an antiferromagnetic (in other words, open-shell singlet) state, and we show that this singlet is not necessarily a diradical, because the spatially separated magnetizations for the spin-up and spin-down electrons increase with the size of the acene. For example, our results indicate that there are about four spin-up electrons localized at one zigzag edge of 20-acene. The reason that both acenes and polyacene have the antiferromagnetic ground state is due to the zigzag-shaped boundaries, which cause pi-electrons to localize and form spin orders at the edges. Both wider graphene ribbons and large rectangular-shaped polycyclic aromatic hydrocarbons have been shown to share this antiferromagnetic grou...

  5. [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.

  6. Electronic ground state of Ni$_2^+$

    CERN Document Server

    Zamudio-Bayer, V; Bülow, C; Leistner, G; Terasaki, A; Issendorff, B v; Lau, J T

    2016-01-01

    The $^{4}\\Phi_{9/2}$ ground state of the Ni$_2^+$ diatomic molecular cation is determined experimentally from temperature and magnetic-field-dependent x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap, where an electronic and rotational temperature of $7.4 \\pm 0.2$ K was achieved by buffer gas cooling of the molecular ion. The contribution of the magnetic dipole term to the x-ray magnetic circular dichroism spin sum rule amounts to $7\\, T_z = 0.17 \\pm 0.06$ $\\mu_B$ per atom, approximately 11 \\% of the spin magnetic moment. We find that, in general, homonuclear diatomic molecular cations of $3d$ transition metals seem to adopt maximum spin magnetic moments in their electronic ground states.

  7. 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...

  8. 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)

  9. 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

    In permafrost areas the seasonal snow cover is an important factor on the ground thermal regime. Snow depth and timing are important in ground insulation from the atmosphere, creating different snow patterns and resulting in spatially variable ground temperatures. The aim of this work is to characterize the interactions between ground thermal regimes and snow cover and the influence on permafrost spatial distribution. The study area is the ice-free terrains of northwestern Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". Air and ground temperatures and snow thickness data where analysed from 4 sites along an altitudinal transect in Hurd Peninsula from 2007 to 2012: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). The data covers 6 cold seasons showing different conditions: i) very cold with thin snow cover; ii) cold with a gradual increase of snow cover; iii) warm with thick snow cover. The data shows three types of periods regarding the ground surface thermal regime and the thickness of snow cover: a) thin snow cover and short-term fluctuation of ground temperatures; b) thick snow cover and stable ground temperatures; c) very thick snow cover and ground temperatures nearly constant at 0°C. a) Thin snow cover periods: Collado Ramos and Ohridski sites show frequent temperature variations, alternating between short-term fluctuations and stable ground temperatures. Nuevo Incinerador displays during most of the winter stable ground temperatures; b) Cold winters with a gradual increase of the snow cover: Nuevo Incinerador, Collado Ramos and Ohridski sites show similar behavior, with a long period of stable ground temperatures; c) Thick snow cover periods: Collado Ramos and Ohridski show long periods of stable ground, while Nuevo Incinerador shows temperatures close to 0°C since the beginning of the winter, due to early snow cover

  10. 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…

  11. 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.

  12. Covering TV Violence Issues in Print and Electronic Media

    OpenAIRE

    ANCA VELICU

    2011-01-01

    Starting from the observation that TV violence is a reality in current Romanian society, taken up as such by the legislators, the academic environment and the civil society, we want to see to what extent this issue is covered in the print and electronic media and how does such coverage is carried out. Therefore, we tried to look at the development of this subject in the online written media, by elaborating on several questions: is the subject „media violence" present in the Romanian media? If...

  13. 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.

  14. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. Covering TV Violence Issues in Print and Electronic Media

    Directory of Open Access Journals (Sweden)

    ANCA VELICU

    2011-03-01

    Full Text Available Starting from the observation that TV violence is a reality in current Romanian society, taken up as such by the legislators, the academic environment and the civil society, we want to see to what extent this issue is covered in the print and electronic media and how does such coverage is carried out. Therefore, we tried to look at the development of this subject in the online written media, by elaborating on several questions: is the subject „media violence" present in the Romanian media? If so, to what extent is this subject presented as a public issue (Cefai, 1996, in a contextual manner (by analyzing the causes, consequences, the different means of tackling the possible negative consequences, the impact levels, etc., or, on the contrary, is it made into a show, being only „news of the day" triggered by a trivial event and treated as such? Who are the social actors (the „voices" invoked in the coverage of this subject?

  2. 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

  3. 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.

  4. Alternative ground states enable pathway switching in biological electron transfer

    Science.gov (United States)

    Abriata, Luciano A.; Álvarez-Paggi, Damián; Ledesma, Gabriela N.; Blackburn, Ninian J.; Vila, Alejandro J.; Murgida, Daniel H.

    2012-01-01

    Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant CuA redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative ground-state electronic wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. These findings suggest a unique role for alternative or “invisible” electronic ground states in directional electron transfer. Moreover, it is shown that this energy gap and, therefore, the equilibrium between ground states can be fine-tuned by minor perturbations, suggesting alternative ways through which protein–protein interactions and membrane potential may optimize and regulate electron–proton energy transduction. PMID:23054836

  5. 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.

  6. Starting electronics all you need to get a grounding in practical electronics

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Starting Electronics is a nine-chapter introductory text to electronics based on feature articles previously published as magazine articles. The opening chapter provides an overview of the fundamentals of electronics. The succeeding chapters present details of some easy-to-do experiments and the current and voltage measurement. The remaining chapters cover some basic components of electronics, including capacitor, integrated circuit, oscillator, filter, diodes, and transistors. This book will prove useful to electronic constructors and students.

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

    Science.gov (United States)

    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

  8. 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.

  9. 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.

  10. Charge transfer to ground-state ions produces free electrons

    Science.gov (United States)

    You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K.

    2017-01-01

    Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne-Kr mixed clusters.

  11. Charge transfer to ground-state ions produces free electrons

    Science.gov (United States)

    You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K

    2017-01-01

    Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne–Kr mixed clusters. PMID:28134238

  12. Sterilization of ground spices by electron beams irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hashigiwa, Masayuki; Nakachi, Ayako; Kobayashi, Hiroshi [K. Kobayashi and Co., Ltd., Kako, Hyogo (Japan)

    1999-09-01

    Each ground spice (Black Pepper, Turmeric, Ginger, Paprika and Basil), which was packaged into polyethylene film, was irradiated by electron beams at 5 different levels: 2, 4, 6, 8 and 10 kGy. Bacteriological tests for total bacterial count were carried out on spices before and after irradiation, but the tests for microfiora were carried out only before irradiation. Total bacterial count decreased in proportion to the level of electron beams. But the decreasing rate for Turmeric, Ginger and Basil was lower compared with that of other spices. The reason seems that rate of contamination by B. pumilus, which is thought as radiation resistant bacteria, was higher on these spices. (author)

  13. Electronically Tunable Quadrature Oscillator Using Translinear Conveyors and Grounded Capacitors

    OpenAIRE

    Sudhanshu Maheshwari

    2003-01-01

    A new electronically tunable current-mode sinusoidal oscillator with three quadrature outputs is presented. The proposed circuit employs three translinear conveyors and two grounded capacitors to realize three quadrature outputs with independent frequency control. The circuit requires no resistors and the frequency of the oscillator can be varied over a wide range by external current control. RSPICE simulation results using the bipolar implementation of translinear conveyors are given to s...

  14. Ground-state electronic structure of actinide monocarbides and mononitrides

    DEFF Research Database (Denmark)

    Petit, Leon; Svane, Axel; Szotek, Z.

    2009-01-01

    The self-interaction corrected local spin-density approximation is used to investigate the ground-state valency configuration of the actinide ions in the actinide monocarbides, AC (A=U,Np,Pu,Am,Cm), and the actinide mononitrides, AN. The electronic structure is characterized by a gradually...... increasing degree of f electron localization from U to Cm, with the tendency toward localization being slightly stronger in the (more ionic) nitrides compared to the (more covalent) carbides. The itinerant band picture is found to be adequate for UC and acceptable for UN, while a more complex manifold...... of competing localized and delocalized f-electron configurations underlies the ground states of NpC, PuC, AmC, NpN, and PuN. The fully localized 5f-electron configuration is realized in CmC (f7), CmN (f7), and AmN (f6). The observed sudden increase in lattice parameter from PuN to AmN is found to be related...

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 电子设备的接地和接地设计%Ground and Ground Design for Electronic Equipment

    Institute of Scientific and Technical Information of China (English)

    丁小东

    2001-01-01

    从电子设备的安全性和可靠性出发,论述了接地的重要性,并从接地类型、地线作用、接地设计等几方面介绍了有关接地技术的理论及应用。%This essay from electronic equipment of safe and reliability Start, Expound ground of significant, And from ground trpy. ground Line action. Design for ground etc. Servile aspects to introduce have Ground technique of basic knowledge. Basic theory and basic put to use.

  20. 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

  1. 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.

  2. Surprises of electron microscopic imaging of proteins and polymers covering gold nanoparticles layer by layer.

    Science.gov (United States)

    Pyshnaya, Inna A; Razum, Kristina V; Dolodoev, Anton S; Shashkova, Valeriya V; Ryabchikova, Elena I

    2017-02-01

    Gold nanoparticles (GNPs) are used in complicated nanoconstructions, and their preparation implies careful analysis of the intermediate and resulting products, including visualisation of the NPs. Visualisation of protein and/or organic polymer covers on GNPs using electron microscopy (EM) was a goal of this study. We covered GNPs with human serum albumin or PEG, and then added a second layer of branched or linear polyethyleneimine. EM studies were supplemented with dynamic light scattering, spectrophotometry and gel electrophoresis, which confirmed the presence and integrity of a cover on GNPs in mixtures with uranylacetate (UA) or phosphotungstic acid (PTA). Covered GNPs were contrasted 'on a drop' or in suspension with UA (pH 4.5) or PTA (pH 0.5, 3.0, 5.0 and 7.0), and studied by transmission EM. A cover on GNPs becomes visible as the result of direct interaction of UA or PTA with the components of a layer. The same NPs could look 'naked' or demonstrate a distinct cover of average electron density. The most distinct images of the layers were obtained using PTA at pH 0.5. Thus, visualisation of protein and/or polymeric layers covering the GNPs by EM depends on the type of contrasting reagent and contrasting conditions, but does not depend on surface charge of the NPs and the chemical nature of a cover.

  3. 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...

  4. 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

  5. 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

  6. 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.

  7. 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

  8. [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.

  9. 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.

  10. 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.

  11. Exact many-electron ground states on diamond and triangle Hubbard chains

    OpenAIRE

    2008-01-01

    We construct exact ground states of interacting electrons on triangle and diamond Hubbard chains. The construction requires (i) a rewriting of the Hamiltonian into positive semidefinite form, (ii) the construction of a many-electron ground state of this Hamiltonian, and (iii) the proof of the uniqueness of the ground state. This approach works in any dimension, requires no integrability of the model, and only demands sufficiently many microscopic parameters in the Hamiltonian which have to fu...

  12. Electron emission from MOS electron emitters with clean and cesium covered gold surface

    DEFF Research Database (Denmark)

    Nielsen, Gunver; Thomsen, Lasse Bjørchmar; Johansson, Martin;

    2009-01-01

    MOS (metal-oxide-semiconductor) electron emitters consisting of a Si substrate, a SiO2 tunnel barrier and a Ti (1 nm)/Au(7 nm) top-electrode, with an active area of 1 cm(2) have been produced and studied with surface science techniques under UHV (ultra high vacuum) conditions and their emission c...

  13. 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

  14. Electron momentum spectroscopy of dimethyl ether taking account of nuclear dynamics in the electronic ground state

    Energy Technology Data Exchange (ETDEWEB)

    Morini, Filippo; Deleuze, Michael Simon, E-mail: michael.deleuze@uhasselt.be [Center of Molecular and Materials Modelling, Hasselt University, Agoralaan Gebouw D, B-3590 Diepenbeek (Belgium); Watanabe, Noboru; Kojima, Masataka; Takahashi, Masahiko [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

    2015-10-07

    The influence of nuclear dynamics in the electronic ground state on the (e,2e) momentum profiles of dimethyl ether has been analyzed using the harmonic analytical quantum mechanical and Born-Oppenheimer molecular dynamics approaches. In spite of fundamental methodological differences, results obtained with both approaches consistently demonstrate that molecular vibrations in the electronic ground state have a most appreciable influence on the momentum profiles associated to the 2b{sub 1}, 6a{sub 1}, 4b{sub 2}, and 1a{sub 2} orbitals. Taking this influence into account considerably improves the agreement between theoretical and newly obtained experimental momentum profiles, with improved statistical accuracy. Both approaches point out in particular the most appreciable role which is played by a few specific molecular vibrations of A{sub 1}, B{sub 1}, and B{sub 2} symmetries, which correspond to C–H stretching and H–C–H bending modes. In line with the Herzberg-Teller principle, the influence of these molecular vibrations on the computed momentum profiles can be unraveled from considerations on the symmetry characteristics of orbitals and their energy spacing.

  15. 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.

  16. Topology optimization of an electronics cover plate with respect to eigenfrequencies

    DEFF Research Database (Denmark)

    A. Kristensen, Anders Schmidt

    In the present paper it is illustrated how topology optimization with respect to eigenfrequency can be applied effectively in the product development process. The topology optimization code is implemented in ANSYS by a so called UPF. The maximization of eigenfrequency as objective is invoked...... into the existing code. As an example is chosen an electronics cover plate. The resulting design devised by the topology optimization yield a significant higher eigenfrequency than obtained by traditional design methods and experience....

  17. 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.

  18. Vacuum polarization screening corrections to the ground state energy of two-electron ions

    CERN Document Server

    Artemiev, A N; Yerokhin, V A

    1997-01-01

    Vacuum polarization screening corrections to the ground state energy of two-electron ions are calculated in the range $Z=20-100$. The calculations are carried out for a finite nucleus charge distribution.

  19. Ground Source Heat Pump in Heating System with Electronics Monitoring

    Directory of Open Access Journals (Sweden)

    NEAMŢU Ovidiu

    2013-10-01

    Full Text Available The monitoring system is implemented for a ground coupled heat pump in heating/ system. The borehole heat exchangers – which are 150 m long - are filled with a mixture of water and ethilene glycol calledbrine. Metering and monitoring energy consumption is achieved for: heat pump, circulation pumps, additional electrical heating, hot air ventilation systems, control systems with sensors: analog and smart sensors. Instantaneous values are stored in a local computer.

  20. Ground State of a Two-Electron Quantum Dot with a Gaussian Confining Potential

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2006-01-01

    We investigate the ground-state properties of a two-dimensional two-electron quantum dot with a Gaussian confining potential under the influence of perpendicular homogeneous magnetic field. Calculations are carried out by using the method of numerical diagonalization of Hamiltonian matrix within the effective-mass approximation. A ground-state behaviour (singlet→triplet state transitions) as a function of the strength of a magnetic field has been found. It is found that the dot radius R of the Gaussian potential is important for the ground-state transition and the feature of ground-state for the Gaussian potential quantum dot (QD), and the parabolic potential QDs are similar when R is larger. The larger the quantum dot radius, the smaller the magnetic field for the singlet-triplet transition of the ground-state of two interacting electrons in the Gaussian quantum dot.

  1. Ground State Transitions in Vertically Coupled Four-Layer Single Electron Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    WANGAn-Mei; XIEWen-Fang

    2005-01-01

    We study a four-electron system in a vertically coupled four-layer quantum dot under a magnetic field by the exact diagonalization of the Hamiltonian matr/x. We find that discontinuous ground-state energy transitions are induced by an external magnetic field. We find that dot-dot distance and electron-electron interaction strongly affect the low-lying states of the coupled quantum dots. The inter-dot correlation leads to some sequences of possible disappearances of ground state transitions, which are present for uncoupled dots.

  2. Ground State Transitions in Vertically Coupled Four-Layer Single Electron Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    WANG An-Mei; XIE Wen-Fang

    2005-01-01

    We study a four-electron system in a vertically coupled four-layer quantum dot under a magnetic field by the exact diagonalization of the Hamiltonian matrix. We find that discontinuous ground-state energy transitions are induced by an external magnetic field. We find that dot-dot distance and electron-electron interaction strongly affect the low-lying states of the coupled quantum dots. The inter-dot correlation leads to some sequences of possible disappearances of ground state transitions, which are present for uncoupled dots.

  3. 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.

  4. 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

  5. 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.

  6. Electronic structure, total energies, and STM images of clean and oxygen-covered Al(111)

    DEFF Research Database (Denmark)

    Jacobsen, Joachim; Hammer, Bjørk; Jacobsen, Karsten Wedel

    1995-01-01

    A set of density-functional calculations for clean and O-covered Al(111) are presented. At low O coverages the potential energy surface (PES) of chemisorbed O is investigated. The PES indicates large barriers (0.8 eV) against O diffusion and a large corrugation of the equilibrium O height over...... the Al(111) while only a moderate energy gain (5 eV per atom) is found upon Oz dissociation over the surface. The possible existence of ''hot'' O adatoms after O-2 dissociation is discussed on the basis of the presented PES and existing dynamical simulations on model potentials. At high O coverages...... an attractive O-O interaction is identified together with an enhancement in the dipole moment induced per O atom. Finally, Tersoff-Hamann-type scanning tunneling microscopy (STM) topographs are derived based on the calculated one-electron wave functions and spectra. For the clean Al(111) a theoretical STM...

  7. Spin-Orbit Coupling Controlled J =3 /2 Electronic Ground State in 5 d3 Oxides

    Science.gov (United States)

    Taylor, A. E.; Calder, S.; Morrow, R.; Feng, H. L.; Upton, M. H.; Lumsden, M. D.; Yamaura, K.; Woodward, P. M.; Christianson, A. D.

    2017-05-01

    Entanglement of spin and orbital degrees of freedom drives the formation of novel quantum and topological physical states. Here we report resonant inelastic x-ray scattering measurements of the transition metal oxides Ca3 LiOsO6 and Ba2 YOsO6 , which reveals a dramatic spitting of the t2 g manifold. We invoke an intermediate coupling approach that incorporates both spin-orbit coupling and electron-electron interactions on an even footing and reveal that the ground state of 5 d3-based compounds, which has remained elusive in previously applied models, is a novel spin-orbit entangled J =3 /2 electronic ground state. This work reveals the hidden diversity of spin-orbit controlled ground states in 5 d systems and introduces a new arena in the search for spin-orbit controlled phases of matter.

  8. Exact many-electron ground states on the diamond Hubbard chain

    Science.gov (United States)

    Gulacsi, Zsolt; Kampf, Arno; Vollhardt, Dieter

    2008-03-01

    Exact ground states of interacting electrons on the diamond Hubbard chain in a magnetic field are constructed which exhibit a wide range of properties such as flat-band ferromagnetism, correlation induced metallic, half-metallic, or insulating behavior [1]. The properties of these ground states can be tuned by changing the magnetic flux, local potentials, or electron density.The results show that the studied simple one-dimensional structure displays remarkably complex physical properties. The virtue of tuning different ground states through external parameters points to new possibilities for the design of electronic devices which can switch between insulating or conducting and nonmagnetic or (fully or partially spin polarized) ferromagnetic states, open new routes for the design of spin-valve devices and gate induced ferromagnetism. [1] Z. Gulacsi, A. Kampf, D. Vollhardt, Phys. Rev. Lett. 99, 026404(2007).

  9. Domain patterning by electron beam of MgO doped lithium niobate covered by resist

    Science.gov (United States)

    Shur, V. Ya.; Chezganov, D. S.; Akhmatkhanov, A. R.; Kuznetsov, D. K.

    2015-06-01

    Periodical domain structuring by focused electron beam irradiation of MgO-doped lithium niobate (MgOCLN) single crystalline plate covered by resist layer was studied both experimentally and by computer simulation. The dependences of domain size on the charge dose and distance between isolated domains were measured. It has been shown that the quality of periodical domain pattern depends on the thickness of resist layer and electron energy. The experimentally obtained periodic domain structures have been divided into four types. The irradiation parameters for the most uniform patterning were obtained experimentally. It was shown by computer simulation that the space charge slightly touching the crystal surface produced the maximum value of electric field at the resist/LN interface thus resulting in the best pattern quality. The obtained knowledge allowed us to optimize the poling process and to make the periodical domain patterns in 1-mm-thick wafers with an area up to 1 × 5 mm2 and a period of 6.89 μm for green light second harmonic generation. Spatial distribution of the efficiency of light frequency conversion confirmed the high homogeneity of the tailored domain patterns.

  10. 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,...

  11. Ground State Transitions of Four-Electron Quantum Dots in Zero Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    KANG Shuai; XIE Wen-Fang; LIU Yi-Ming; SHI Ting-Yun

    2008-01-01

    In this paper, we study four electrons confined in a parabolic quantum dot in the absence of magnetic field, by the exact diagonalization method. The ground-state electronic structures and orbital and spin angular momenta transitions as a function of the confined strength are investigated. We find that the confinement may cause accidental degeneracies between levels with different low-lying states and the inversion of the energy values. The present results are useful to understand the optical properties and internal electron-electron correlations of quantum dot materials.

  12. The ground electronic state of KCs studied by Fourier transform spectroscopy

    Science.gov (United States)

    Ferber, R.; Klincare, I.; Nikolayeva, O.; Tamanis, M.; Knöckel, H.; Tiemann, E.; Pashov, A.

    2008-06-01

    We present here the first analysis of laser induced fluorescence (LIF) of the KCs molecule obtaining highly accurate data and perform a direct potential construction for the X 1Σ+ ground state in a wide range of internuclear distances. KCs molecules were produced by heating a mixture of K and Cs metals in a heat pipe at a temperature of about 270 °C. KCs fluorescence was induced by different laser sources: the 454.5, 457.9, 465.8, and 472.7 nm lines of an Ar+ laser, a dye laser with Rhodamine 6G dye (excitation at around 16 870 cm-1), and 850 and 980 nm diode lasers (11 500-11 900 and 10 200-10 450 cm-1 tuning ranges, respectively). The LIF to the ground state was recorded by a Bruker IFS-125HR Fourier transform spectrometer with a spectral resolution of 0.03 cm-1. Particularly, by applying the 850 nm laser diode we were able to observe LIF progressions to very high vibrational levels of the ground state close to the dissociation limit. The present data field contains 7226 term values for the ground state X 1Σ+ and covers a range from v''=0 to 97 with J'' varying from 12 to 209. More than 10 000 fluorescence lines were used to fit the ground state potential energy curve via the inverted perturbation approach procedure. The present empirical potential extends up to approximately 12.6 A˚ and covers more than 99% of the potential well depth, it describes most of the spectral lines with an accuracy of about 0.003 cm-1 and yields a dissociation energy of 4069.3+/-1.5 cm-1 for the ground state X 1Σ+. First observations of the triplet ground state a 3Σ+ of KCs are presented, and preliminary values of few main molecular constants could be derived.

  13. Electron-attachment processes

    Science.gov (United States)

    Christophorou, L. G.; McCorkle, D. L.; Christodoulides, A. A.

    Topics covered include: modes of production of negative ions, techniques for the study of electron attachment processes, dissociative electron attachment to ground state molecules, dissociative electron attachment to hot molecules (effects of temperature on dissociative electron attachment), molecular parent negative ions, and negative ions formed by ion pair processes and by collisions of molecules with ground state and Rydberg atoms.

  14. 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.

  15. The ground and excited state electron affinities of cytosine and trans-azobenzene

    Science.gov (United States)

    Chen, Edward C. M.; Herder, Charles; Chen, Edward S.

    2007-06-01

    The electron capture detector, reduction potential, electron transfer and photon methods of determining electron affinities are compared. The adiabatic electron affinities are (in eV): t-azobenzene(O 2), 1.578(5); t-azobenzene, 1.378(5); cytosine, 1.043(5) from anion photoelectron spectra. The largest or ground state value for trans-azobenzene and an excited state electron affinity for cytosine, 0.70 eV are also determined by reduction potentials. Other excited state energies are (in eV): t-azobenzene, 0.328(5), 0.589(5), 0.690(5), 0.768(5), 0.954(5), 1.038(5), 1.150(5), 1.275(5) and cytosine, 0.089(5), 0.098(5), 0.198(5), 0.235(5). The cytosine values are consistent with electron transport and radiation damage and repair in DNA.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. High resolution electron energy loss spectroscopy of clean and hydrogen covered Si(001) surfaces: first principles calculations.

    Science.gov (United States)

    Patterson, C H

    2012-09-07

    Surface phonons, conductivities, and loss functions are calculated for reconstructed (2×1), p(2×2) and c(4×2) clean Si(001) surfaces, and (2×1) H and D covered Si(001) surfaces. Surface conductivities perpendicular to the surface are significantly smaller than conductivities parallel to the surface. The surface loss function is compared to high resolution electron energy loss measurements. There is good agreement between calculated loss functions and experiment for H and D covered surfaces. However, agreement between experimental data from different groups and between theory and experiment is poor for clean Si(001) surfaces. Formalisms for calculating electron energy loss spectra are reviewed and the mechanism of electron energy losses to surface vibrations is discussed.

  1. 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

  2. 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

  3. Precipitation of radiation belt electrons by EMIC waves, observed from ground and space

    Energy Technology Data Exchange (ETDEWEB)

    Jordanova, Vania K [Los Alamos National Laboratory; Miyoski, Y [NAGOYA UNIV; Sakaguchi, K [NAGOYA UNIV; Shiokawa, K [NAGOYA UNIV; Evans, D S [NOAA, BOULDER; Albert, Jay [AFRL; Connors, M [UNIV OF ATHABASCA

    2008-01-01

    We show evidence that left-hand polarised electromagnetic ion cyclotron (EMIC) plasma waves can cause the loss of relativistic electrons into the atmosphere. Our unique set of ground and satellite observations shows coincident precipitation of ions with energies of tens of keY and of relativistic electrons into an isolated proton aurora. The coincident precipitation was produced by wave-particle interactions with EMIC waves near the plasmapause. The estimation of pitch angle diffusion coefficients supports that the observed EMIC waves caused coincident precipitation ofboth ions and relativistic electrons. This study clarifies that ions with energies of tens of ke V affect the evolution of relativistic electrons in the radiation belts via cyclotron resonance with EMIC waves, an effect that was first theoretically predicted in the early 1970's.

  4. Automatic Checkout System for Ground Electronics of a Weapon System (Short Communication

    Directory of Open Access Journals (Sweden)

    V. Ashok Kumar

    1997-04-01

    Full Text Available An automatic checkout system (ACOS designed and developed for a surface-to-air missile system is described. The system has a built-in self-check and has been extensively used for checking faults in the subsystems of ground electronics. It has resulted in saving a lot of effort in quickly diagnosing and rectifying faults. The salient features of the ACOS have been described and the scope for further work in this area has been outline.

  5. Ground-state energy of the electron liquid in ultrathin wires.

    Science.gov (United States)

    Fogler, Michael M

    2005-02-11

    The ground-state energy and the density correlation function of the electron liquid in a thin one-dimensional wire are computed. The calculation is based on an approximate mapping of the problem with a realistic Coulomb interaction law onto exactly solvable models of mathematical physics. This approach becomes asymptotically exact in the limit of a small wire radius but remains numerically accurate even for modestly thin wires.

  6. Determination of ground and excited state dipole moments via electronic Stark spectroscopy: 5-methoxyindole.

    Science.gov (United States)

    Wilke, Josefin; Wilke, Martin; Meerts, W Leo; Schmitt, Michael

    2016-01-28

    The dipole moments of the ground and lowest electronically excited singlet state of 5-methoxyindole have been determined by means of optical Stark spectroscopy in a molecular beam. The resulting spectra arise from a superposition of different field configurations, one with the static electric field almost parallel to the polarization of the exciting laser radiation, the other nearly perpendicular. Each field configuration leads to different intensities in the rovibronic spectrum. With an automated evolutionary algorithm approach, the spectra can be fit and the ratio of both field configurations can be determined. A simultaneous fit of two spectra with both field configurations improved the precision of the dipole moment determination by a factor of two. We find a reduction of the absolute dipole moment from 1.59(3) D to 1.14(6) D upon electronic excitation to the lowest electronically excited singlet state. At the same time, the dipole moment orientation rotates by 54(∘) showing the importance of the determination of the dipole moment components. The dipole moment in the electronic ground state can approximately be obtained from a vector addition of the indole and the methoxy group dipole moments. However, in the electronically excited state, vector addition completely fails to describe the observed dipole moment. Several reasons for this behavior are discussed.

  7. Electron-electron interaction in strong electromagnetic fields: the two-electron contribution to the ground-state energy in He-like uranium.

    Science.gov (United States)

    Gumberidze, A; Stöhlker, Th; Banaś, D; Beckert, K; Beller, P; Beyer, H F; Bosch, F; Cai, X; Hagmann, S; Kozhuharov, C; Liesen, D; Nolden, F; Ma, X; Mokler, P H; Orsić-Muthig, A; Steck, M; Sierpowski, D; Tashenov, S; Warczak, A; Zou, Y

    2004-05-21

    Radiative recombination transitions into the ground state of cooled bare and hydrogenlike uranium ions were measured at the storage ring ESR. By comparing the corresponding x-ray centroid energies, this technique allows for a direct measurement of the electron-electron contribution to the ionization potential in the heaviest He-like ions. For the two-electron contribution to the ionization potential of He-like uranium we obtain a value of 2248+/-9 eV. This represents the most accurate determination of two-electron effects in the domain of high-Z He-like ions, and the accuracy reaches already the size of the specific two-electron radiative QED corrections.

  8. 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.

  9. 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.

  10. 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.

  11. Linear energy relationships in ground state proton transfer and excited state proton-coupled electron transfer.

    Science.gov (United States)

    Gamiz-Hernandez, Ana P; Magomedov, Artiom; Hummer, Gerhard; Kaila, Ville R I

    2015-02-12

    Proton-coupled electron transfer (PCET) processes are elementary chemical reactions involved in a broad range of radical and redox reactions. Elucidating fundamental PCET reaction mechanisms are thus of central importance for chemical and biochemical research. Here we use quantum chemical density functional theory (DFT), time-dependent density functional theory (TDDFT), and the algebraic diagrammatic-construction through second-order (ADC(2)) to study the mechanism, thermodynamic driving force effects, and reaction barriers of both ground state proton transfer (pT) and photoinduced proton-coupled electron transfer (PCET) between nitrosylated phenyl-phenol compounds and hydrogen-bonded t-butylamine as an external base. We show that the obtained reaction barriers for the ground state pT reactions depend linearly on the thermodynamic driving force, with a Brønsted slope of 1 or 0. Photoexcitation leads to a PCET reaction, for which we find that the excited state reaction barrier depends on the thermodynamic driving force with a Brønsted slope of 1/2. To support the mechanistic picture arising from the static potential energy surfaces, we perform additional molecular dynamics simulations on the excited state energy surface, in which we observe a spontaneous PCET between the donor and the acceptor groups. Our findings suggest that a Brønsted analysis may distinguish the ground state pT and excited state PCET processes.

  12. Low-Cost Tracking Ground Terminal Designed to Use Cryogenically Cooled Electronics

    Science.gov (United States)

    Wald, Lawrence W.; Romanofsky, Robert R.; Warner, Joseph D.

    2000-01-01

    A computer-controlled, tracking ground terminal will be assembled at the NASA Glenn Research Center at Lewis Field to receive signals transmitted by the Glenn's Direct Data Distribution (D3) payload planned for a shuttle flight in low Earth orbit. The terminal will enable direct data reception of up to two 622-megabits-per-second (Mbps) beams from the space-based, K-band (19.05-GHz) transmitting array at an end-user bit error rate of up to 10(exp -12). The ground terminal will include a 0.9-m-diameter receive-only Cassegrain reflector antenna with a corrugated feed horn incorporating a dual circularly polarized, K-band feed assembly mounted on a multiaxis, gimbaled tracking pedestal as well as electronics to receive the downlink signals. The tracking system will acquire and automatically track the shuttle through the sky for all elevations greater than 20 above the horizon. The receiving electronics for the ground terminal consist of a six-pole microstrip bandpass filter, a three-stage monolithic microwave integrated circuit (MMIC) amplifier, and a Stirling cycle cryocooler (1 W at 80 K). The Sterling cycle cryocooler cools the front end of the receiver, also known as the low-noise amplifier (LNA), to about 77 K. Cryocooling the LNA significantly increases receiver performance, which is necessary so that it can use the antenna, which has an aperture of only 0.9 m. The following drawing illustrates the cryoterminal.

  13. Comparative study on earthquake and ground based transmitter induced radiation belt electron precipitation at middle latitudes

    Directory of Open Access Journals (Sweden)

    N. F. Sidiropoulos

    2011-07-01

    Full Text Available We examined (peak-to-background flux ratio p/b > 20 energetic electron bursts in the presence of VLF activity, as observed from the DEMETER satellite at low altitudes (~700 km. Our statistical analysis of measurements during two 6-month periods suggests that: (a the powerful transmitter NWC causes the strongest effects on the inner radiation belts in comparison with other ground-based VLF transmitters, (b the NWC transmitter was responsible for only ~1.5 % of total electron bursts examined during the 6-month period (1 July 2008 to 31 December 2008, (c VLF transmitter-related electron bursts are accompanied by the presence of a narrow band emission centered at the radiating frequency emission, whereas the earthquake-related electron bursts are accompanied by the presence of broadband emissions from a few kHz to >20 KHz, (d daytime events are less preferable than nighttime events, but this asymmetry was found to be less evident when the powerful transmitter NWC was turned off and (d seismic activity most probably dominated the electromagnetic interactions producing the electron precipitation at middle latitudes. The results of this study support the proposal that the detection of radiation belt electron precipitation, besides other kinds of studies, is a useful tool for earthquake prediction research.

  14. New Shell Structures and Their Ground Electronic States in Spherical Quantum Dots (II) under Magnetic Field

    Science.gov (United States)

    Asari, Yusuke; Takeda, Kyozaburo; Tamura, Hiroyuki

    2005-04-01

    We theoretically studied the electronic structure of the three-dimensional spherical parabolic quantum dot (3D-SPQD) under a magnetic field. We obtained the quantum dot orbitals (QDOs) and determined the ground state by using the extended UHF approach where the expectation values of the z component of the total orbital angular momentum are conserved during the scf-procedure. The single-electron treatment predicts that the applied magnetic field (B) creates k-th new shells at the magnetic field of Bk=k(k+2)/(k+1)ω0 with the shell-energy interval of \\hbarω0/(k+1), where ω0(=\\hbar/m*l02) is the characteristic frequency originating from the spherical parabolic confinement potential. These shells are formed by the level crossing among multiple QDOs. The interelectron interaction breaks the simple level crossing but causes complicated dependences among the total energy, the chemical potential and their differences (magic numbers) with the magnetic field or the number of confinement electrons. The ground state having a higher spin multiplicity is theoretically predicted on the basis of the \\textit{quasi}-degeneracies of the QDOs around these shells.

  15. ARTICLE : Comparison of Quality of Bologna Sausage Manufactured by Electron Beam or X-Ray Irradiated Ground Pork

    National Research Council Canada - National Science Library

    Mee Hye Shin; ; Ju Woon Lee; Young Min Yoon; Jong Heon Kim; Byeong Geum Moon; Jae Hun Kim; Beom Suk Song

    2014-01-01

    Ground lean pork was irradiated by an electron beam or X-rays to compare the effects of two types of radiation generated by a linear accelerator on the quality of Bologna sausage as a model meat product...

  16. Quantum Cohesion Oscillation of Electron Ground State in Low Temperature Laser Plasma

    Science.gov (United States)

    Zhao, Qingxun; Zhang, Ping; Dong, Lifang; Zhang, Kaixi

    1996-01-01

    The development of radically new technological and economically efficient methods for obtaining chemical products and for producing new materials with specific properties requires the study of physical and chemical processes proceeding at temperature of 10(exp 3) to 10(exp 4) K, temperature range of low temperature plasma. In our paper, by means of Wigner matrix of quantum statistical theory, a formula is derived for the energy of quantum coherent oscillation of electron ground state in laser plasma at low temperature. The collective behavior would be important in ion and ion-molecule reactions.

  17. 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.

  18. 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

  19. Influence of variations in the electron-electron interaction on the ground state metric space "band structure" of a two-electron magnetic system

    Science.gov (United States)

    Sharp, P. M.; D'Amico, I.

    2016-02-01

    We consider a model system of two electrons confined in a two-dimensional harmonic oscillator potential, with the electrons interacting via an α / r2 potential, and subject to a magnetic field applied perpendicular to the plane of confinement. Our results show that variations in the strength of the electron-electron interaction generate a "band structure" in ground state metric spaces, which shares many characteristics with those generated as a result of varying the confinement potential. In particular, the metric spaces for wavefunctions, particle densities, and paramagnetic current densities all exhibit distinct "bands" and "gaps". The behavior of the polar angle of the bands also shares traits with that obtained by varying the confinement potential, but the behavior of the arc lengths of the bands on the metric space spheres can be seen to be different for the two cases and opposite for a large range of angular momentum values. The findings here and in Refs. [1,2] demonstrate that the "band structure" that arises in ground state metric spaces when a magnetic field is applied is a robust feature.

  20. Electronic structure of thiolate-covered gold nanoparticles: Au102(MBA)44.

    Science.gov (United States)

    Li, Yan; Galli, Giulia; Gygi, François

    2008-09-23

    We present first principles, density functional theory (DFT) calculations of the structural and electronic properties of thiolate-protected gold nanoparticles [Au(102)(MBA)(44) ] that have been recently crystallized and measured by X-ray diffraction. Our calculations yield structural properties in very good agreement with experiment and reveal the impact of thiolate adsorption on both the surface geometry and the electronic structure of the gold core; in particular, within DFT we observe the emergence of an energy gap of about 0.5 eV, upon MBA adsorption. Using a localized orbital analysis, we characterize the electron distribution in the nanoparticle and provide insight into the bonding of thiolates on curved gold surfaces.

  1. Optimal control of the initiation of a pericyclic reaction in the electronic ground state

    Indian Academy of Sciences (India)

    Timm Bredtmann; Jörn Manz

    2012-01-01

    Pericyclic reactions in the electronic ground state may be initiated by down-chirped pump-dump sub-pulses of an optimal laser pulse, in the ultraviolet (UV) frequency and sub-10 femtosecond (fs) time domain. This is demonstrated by means of a quantum dynamics model simulation of the Cope rearrangement of Semibullvalene. The laser pulse is designed by means of optimal control theory, with detailed analysis of the mechanism. The theoretical results support the recent experimental initiation of a pericyclic reaction. The present approach provides an important step towards monitoring asynchronous electronic fluxes during synchronous nuclear pericyclic reaction dynamics, with femto-to-attosecond time resolution, as motivated by the recent prediction of our group.

  2. On large amplitude motions of simplest amides in the ground and excited electronic states

    Science.gov (United States)

    Tukachev, N. V.; Bataev, V. A.; Godunov, I. A.

    2016-12-01

    For the formamide, acetamide, N-methylformamide and N-methylacetamide molecules in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states equilibrium geometry parameters, harmonic vibrational frequencies, barriers to conformational transitions and conformer energy differences were estimated by means of MP2, CCSD(T), CASSCF, CASPT2 and MRCI ab initio methods. One-, two- and three-dimensional potential energy surface (PES) sections corresponding to different large amplitude motions (LAM) were calculated by means of MP2/aug-cc-pVTZ (S0) and CASPT2/cc-pVTZ (S1,T1). For these molecules, in each excited electronic state six minima were found on 2D PES sections. Using PES sections, different anharmonic vibrational problems were solved and the frequencies of large amplitude vibrations were determined.

  3. ELECTRON AND PROTON ACCELERATION DURING THE FIRST GROUND LEVEL ENHANCEMENT EVENT OF SOLAR CYCLE 24

    Energy Technology Data Exchange (ETDEWEB)

    Li, C.; Sun, L. P. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Firoz, Kazi A. [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Miroshnichenko, L. I., E-mail: lic@nju.edu.cn [N. V. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN), Russian Academy of Sciences, Troitsk, 142190 Moscow Region (Russian Federation)

    2013-06-10

    High-energy particles were recorded by near-Earth spacecraft and ground-based neutron monitors (NMs) on 2012 May 17. This event was the first ground level enhancement (GLE) of solar cycle 24. In this study, we try to identify the acceleration source(s) of solar energetic particles by combining in situ particle measurements from the WIND/3DP, GOES 13, and solar cosmic rays registered by several NMs, as well as remote-sensing solar observations from SDO/AIA, SOHO/LASCO, and RHESSI. We derive the interplanetary magnetic field (IMF) path length (1.25 {+-} 0.05 AU) and solar particle release time (01:29 {+-} 00:01 UT) of the first arriving electrons by using their velocity dispersion and taking into account contamination effects. We found that the electron impulsive injection phase, indicated by the dramatic change in the spectral index, is consistent with flare non-thermal emission and type III radio bursts. Based on the potential field source surface concept, modeling of the open-field lines rooted in the active region has been performed to provide escape channels for flare-accelerated electrons. Meanwhile, relativistic protons are found to be released {approx}10 minutes later than the electrons, assuming their scatter-free travel along the same IMF path length. Combining multi-wavelength imaging data of the prominence eruption and coronal mass ejection (CME), we obtain evidence that GLE protons, with an estimated kinetic energy of {approx}1.12 GeV, are probably accelerated by the CME-driven shock when it travels to {approx}3.07 solar radii. The time-of-maximum spectrum of protons is typical for shock wave acceleration.

  4. System for electronic transformation and geographic correlation of satellite television information. [cloud cover photography

    Science.gov (United States)

    Dubenskiy, V. P.; Nemkovskiy, B. L.; Rodionov, B. N.

    1974-01-01

    An electronic transformation and correlation system has been developed for the Meteor space weather system which provides transformation and scaling of the original picture, accounts for satellite flight altitude and inclinations of the optical axes of the transmitting devices, and simultaneously superposes the geographical coordinate grid on the transformed picture.

  5. 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..

  6. 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.

  7. [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.

  8. Parasitic Effects of Grounding Paths on Common-Mode EMI Filter's Performance in Power Electronics Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuo [ORNL; Maillet, Yoann [Virginia Polytechnic Institute and State University (Virginia Tech); Wang, Fei [ORNL; Lai, Rixin [General Electric; Luo, Fang [Virginia Polytechnic Institute and State University (Virginia Tech); Boroyevich, Dushan [Virginia Polytechnic Institute and State University (Virginia Tech)

    2010-01-01

    High-frequency common-mode (CM) electromagnetic-interference (EMI) noise is difficult to suppress in electronics systems. EMI filters are used to suppress CM noise, but their performance is greatly affected by the parasitic effects of the grounding paths. In this paper, the parasitic effects of the grounding paths on an EMI filter's performance are investigated in a motor-drive system. The effects of the mutual inductance between two grounding paths are explored. Guidelines for the grounding of CM EMI filters are derived. Simulations and experiments are finally carried out to verify the theoretical analysis.

  9. Electron and proton acceleration during the first ground level enhancement of solar cycle 24

    CERN Document Server

    Li, C; Sun, L P; Miroshnichenko, L I

    2013-01-01

    High-energy particles were recorded by near-Earth spacecraft and ground-based neutron monitors (NMs) on 2012 May 17. This event was the first ground level enhancement (GLE) of solar cycle 24. In this study, we try to identify the acceleration source(s) of solar energetic particles by combining in situ particle measurements from the WIND/3DP, GOES 13, and solar cosmic rays registered by several NMs, as well as remote-sensing solar observations from SDO/AIA, SOHO/LASCO, and RHESSI. We derive the interplanetary magnetic field (IMF) path length (1.25 +/- 0.05 AU) and solar particle release time (01:29 +/- 00:01 UT) of the first arriving electrons by using their velocity dispersion and taking into account contamination effects. We found that the electron impulsive injection phase, indicated by the dramatic change in the spectral index, is consistent with flare non-thermal emission and type III radio bursts. Based on the potential field source surface concept, modeling of the open-field lines rooted in the active r...

  10. The Potential Energy Surface for the Electronic Ground State of H 2Se Derived from Experiment

    Science.gov (United States)

    Jensen, P.; Kozin, I. N.

    1993-07-01

    The present paper reports a determination of the potential energy surface for the electronic ground state of the hydrogen selenide molecule through a direct least-squares fitting to experimental data using the MORBID (Morse oscillator rigid bender internal dynamics) approach developed by P. Jensen [ J. Mol. Spectrosc.128, 478-501 (1988); J. Chem. Soc. Faraday Trans. 284, 1315-1340 (1988)]. We have fitted a selection of 303 rotation-vibration energy spacings of H 280Se, D 280Se, and HD 80Se involving J ≤ 5 with a root-mean-square deviation of 0.0975 cm -1 for the rotational energy spacings and 0.268 cm -1 for the vibrational spacings. In the fitting, 14 parameters were varied. On the basis of the fitted potential surface we have studied the cluster effect in the vibrational ground state of H 2Se, i.e., the formation of nearly degenerate, four-member groups of rotational energy levels [see I. N. Kozin, S. Klee, P. Jensen, O. L. Polyansky, and I. M. Pavlichenkov. J. Mol. Spectrosc., 158, 409-422 (1993), and references therein]. The cluster formation becomes more pronounced with increasing J. For example, four-fold clusters formed in the vibrational ground state of H 280Se at J = 40 are degenerate to within a few MHz. Our predictions of the D 280Se energy spectrum show that for this molecule, the cluster formation is displaced towards higher J values than arc found for H 280Se. In the vibrational ground state, the qualitative deviation from the usual rigid rotor picture starts at J = 12 for H 280Se and at J = 18 for D 280Se, in full agreement with predictions from semiclassical theory. An interpretation of the cluster eigenstates is discussed.

  11. Examining the ground layer of St. Anthony from Padua 19th century oil painting by Raman spectroscopy, scanning electron microscopy and X-ray diffraction

    Science.gov (United States)

    Vančo, Ľubomír; Kadlečíková, Magdaléna; Breza, Juraj; Čaplovič, Ľubomír; Gregor, Miloš

    2013-01-01

    In this paper we studied the material composition of the ground layer of a neoclassical painting. We used Raman spectroscopy (RS) as a prime method. Thereafter scanning electron microscopy combined with energy dispersive spectroscopy (SEM-EDS) and X-ray powder diffraction (XRD) were employed as complementary techniques. The painting inspected was of the side altar in King St. Stephen's Church in Galanta (Slovakia), signed and dated by Jos. Chr. Mayer 1870. Analysis was carried out on both covered and uncovered ground layers. Four principal compounds (barite, lead white, calcite, dolomite) and two minor compounds (sphalerite, quartz) were identified. This ground composition is consistent with the 19th century painting technique used in Central Europe consisting of white pigments and white fillers. Transformation of lead white occurred under laser irradiation. Subdominant Raman peaks of the components were measured. The observed results elucidate useful partnership of RS and SEM-EDS measurements supported by X-ray powder diffraction as well as possibilities and limitations of non-destructive analysis of covered lower layers by RS.

  12. Stretchable Multichannel Electromyography Sensor Array Covering Large Area for Controlling Home Electronics with Distinguishable Signals from Multiple Muscles.

    Science.gov (United States)

    Kim, Namyun; Lim, Taehoon; Song, Kwangsun; Yang, Sung; Lee, Jongho

    2016-08-17

    Physiological signals provide important information for biomedical applications and, more recently, in the form of wearable electronics for active interactions between bodies and external environments. Multiple physiological sensors are often required to map distinct signals from multiple points over large areas for more diverse applications. In this paper, we present a reusable, multichannel, surface electromyography (EMG) sensor array that covers multiple muscles over relatively large areas, with compliant designs that provide different levels of stiffness for repetitive uses, without backing layers. Mechanical and electrical characteristics along with distinct measurements from different muscles demonstrate the feasibility of the concept. The results should be useful to actively control devices in the environment with one array of wearable sensors, as demonstrated with home electronics.

  13. ELECTRONIC STRUCTURE FOR THE GROUND STATE OF T1H FROM RELATIVISTIC MULTICONFIGURATION SCF CALCULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, P.A.; Pitzer, K.S.

    1980-07-01

    The dissociation curve for the ground state of TlH was computed using a relativistic {omega}-{omega} coupling formalism. The relativistic effects represented by the Dirac equation were introduced using effective potentials generated from atomic Dirac-Fock wave functions using a generalization of the improved effective potential formulation of Christiansen, Lee, and Pitzer. The multiconfiguration SCF treatment used is a generalization of the two-component molecular spinor formalism of Lee, Ermler, and Pitzer. Using a five configuration wave function we were able to obtain approximately 85% of the experimental dissociation energy. Our computations indicate that the bond is principally sigma in form, despite the large spin-orbit splitting in atomic thallium. Furthermore the bond appears to be slightly ionic (Tl{sup +}H{sup -}) with about 0.3 extra electron charge on the hydrogen.

  14. 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

  15. Should electronic cigarette use be covered by clean indoor air laws?

    Science.gov (United States)

    Yingst, Jessica M; Veldheer, Susan; Hammett, Erin; Hrabovsky, Shari; Foulds, Jonathan

    2017-03-01

    Some jurisdictions have passed legislation that bans electronic cigarette (e-cig) use (vaping) in public places similarly to smoking. Many other jurisdictions have not yet determined how to regulate vaping in public places. This study examined the proportion of current e-cig users who find their vaping restricted in public places and further evaluated factors associated with the differences between restricted and unrestricted vapers. 3960 experienced exclusive e-cig users completed an online survey from December 2012 to May 2014 about their e-cig use. Restricted vapers were defined as those who reported not being able to vape in places where smoking is typically banned. Unrestricted vapers were defined as those who reported being able vape in places where smoking is typically banned. χ(2) and two-sided t-tests were used as appropriate to determine differences between variables of interest. Participants were a mean age of 40.3 years, 72.0% male, 91.8% white and 85.1% were from the USA. 26.1% (n=1034) of users reported restricted vaping, while 73.9% (n=2926) reported unrestricted vaping. Restricted vapers used less frequently (pcig. Of the restricted vapers, the majority (88%) do not find it difficult to refrain from vaping in places where they are not supposed to vape. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  16. 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

  17. Study of some electronics properties of new superconductor Sr2VO3FeAs in ground state

    Directory of Open Access Journals (Sweden)

    M Majidiyan

    2010-09-01

    Full Text Available In this paper, some electronics properties of new superconductor Sr2VO3FeAs, such as density of states, band structure, density of electron cloud and bound lengths in the ground state have been calculated. According to N(Ef in ground state CV/T value has been estimated. The calculations were performed in the framework of density functional theory (DFT, using the full potential linearized augmented plane wave (FP-LAPW method with the general gradient approximation (GGA.

  18. 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.

  19. The separation of vibrational coherence from ground- and excited-electronic states in P3HT film

    KAUST Repository

    Song, Yin

    2015-06-07

    © 2015 AIP Publishing LLC. Concurrence of the vibrational coherence and ultrafast electron transfer has been observed in polymer/fullerene blends. However, it is difficult to experimentally investigate the role that the excited-state vibrational coherence plays during the electron transfer process since vibrational coherence from the ground- and excited-electronic states is usually temporally and spectrally overlapped. Here, we performed 2-dimensional electronic spectroscopy (2D ES) measurements on poly(3-hexylthiophene) (P3HT) films. By Fourier transforming the whole 2D ES datasets (S (λ 1, T∼ 2, λ 3)) along the population time (T∼ 2) axis, we develop and propose a protocol capable of separating vibrational coherence from the ground- and excited-electronic states in 3D rephasing and nonrephasing beating maps (S (λ 1, ν∼ 2, λ 3)). We found that the vibrational coherence from pure excited electronic states appears at positive frequency (+ ν∼ 2) in the rephasing beating map and at negative frequency (- ν∼ 2) in the nonrephasing beating map. Furthermore, we also found that vibrational coherence from excited electronic state had a long dephasing time of 244 fs. The long-lived excited-state vibrational coherence indicates that coherence may be involved in the electron transfer process. Our findings not only shed light on the mechanism of ultrafast electron transfer in organic photovoltaics but also are beneficial for the study of the coherence effect on photoexcited dynamics in other systems.

  20. Total and single differential cross sections for the electron impact ionization of the ground state of helium

    Energy Technology Data Exchange (ETDEWEB)

    Singh, T.S.C. [Thoubal Coll., Manipur (India). Dept. of Phys.; Choudhury, K.B. [B.K.C. Coll., Calcutta (India). Dept. of Phys.; Singh, M.B. [Manipur Univ. (India). Sch. of Sci.; Deb, N.C. [Indian Association for the Cultivation of Science, Calcutta (India). Dept. of Theoretical Physics; Mukherjee, S.C. [Indian Association for the Cultivation of Science, Calcutta (India). Dept. of Theoretical Physics; Mazumdar, P.S. [Manipur Univ. (India). Sch. of Sci.

    1997-04-01

    Total cross sections (TCS) and single differential cross sections (SDCS) have been computed for the single ionization of the ground state of helium by electron impact in a distorted wave formalism which takes into account the effects of the initial and final channel distortions. The present TCS and SDCS results are in fair agreement with the measured values and other theoretical predictions for the incident electron energy E{sub i} > 150 eV. (orig.).

  1. The Study of Electronic Medical Record Adoption in a Medicare Certified Home Health Agency Using a Grounded Theory Approach

    Science.gov (United States)

    May, Joy L.

    2013-01-01

    The purpose of this qualitative grounded theory study was to examine the experiences of clinicians in the adoption of Electronic Medical Records in a Medicare certified Home Health Agency. An additional goal for this study was to triangulate qualitative research between describing, explaining, and exploring technology acceptance. The experiences…

  2. Determination and Comparison of Carbonyl Stretching Frequency of a Ketone in Its Ground State and the First Electronic Excited State

    Science.gov (United States)

    Bandyopadhyay, Subhajit; Roy, Saswata

    2014-01-01

    This paper describes an inexpensive experiment to determine the carbonyl stretching frequency of an organic keto compound in its ground state and first electronic excited state. The experiment is simple to execute, clarifies some of the fundamental concepts of spectroscopy, and is appropriate for a basic spectroscopy laboratory course. The…

  3. Determination and Comparison of Carbonyl Stretching Frequency of a Ketone in Its Ground State and the First Electronic Excited State

    Science.gov (United States)

    Bandyopadhyay, Subhajit; Roy, Saswata

    2014-01-01

    This paper describes an inexpensive experiment to determine the carbonyl stretching frequency of an organic keto compound in its ground state and first electronic excited state. The experiment is simple to execute, clarifies some of the fundamental concepts of spectroscopy, and is appropriate for a basic spectroscopy laboratory course. The…

  4. Determination of electronic ground state properties of a dinuclear iron(II) spin crossover complex

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, T. O., E-mail: thbauer@rhrk.uni-kl.de [University of Kaiserslautern, Department of Physics (Germany); Schmitz, M.; Graf, M.; Kelm, H.; Krüger, H.-J. [University of Kaiserslautern, Department of Chemistry (Germany); Schünemann, V. [University of Kaiserslautern, Department of Physics (Germany)

    2016-12-15

    The dinuclear complex [(Fe(L-N{sub 4}Me{sub 2})){sub 2}(BiBzIm)](ClO{sub 4}){sub 2}⋅2EtCN (1) has been investigated by Mössbauer spectroscopy carried out in the temperature range from 5 to 150 K with externally applied magnetic fields of up to B = 5 T. By means of a consistent simulation of all experimental data sets within the Spin Hamiltonian formalism, the zero-field splitting D and the rhombicity parameter E/D of the ferrous high-spin (HS) site in this complex was determined to be D = −15.0 ± 1.0 cm{sup −1} and E/D = 0.33 respectively. The sign of the quadrupole splitting of the HS site is positive which indicates that this iron site of the dinuclear complex 1 has an electronic ground state with the d{sub xy} orbital being twofold occupied.

  5. 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.

  6. A QM/MM Approach Using the AMOEBA Polarizable Embedding: From Ground State Energies to Electronic Excitations.

    Science.gov (United States)

    Loco, Daniele; Polack, Étienne; Caprasecca, Stefano; Lagardère, Louis; Lipparini, Filippo; Piquemal, Jean-Philip; Mennucci, Benedetta

    2016-08-09

    A fully polarizable implementation of the hybrid quantum mechanics/molecular mechanics approach is presented, where the classical environment is described through the AMOEBA polarizable force field. A variational formalism, offering a self-consistent relaxation of both the MM induced dipoles and the QM electronic density, is used for ground state energies and extended to electronic excitations in the framework of time-dependent density functional theory combined with a state specific response of the classical part. An application to the calculation of the solvatochromism of the pyridinium N-phenolate betaine dye used to define the solvent ET(30) scale is presented. The results show that the QM/AMOEBA model not only properly describes specific and bulk effects in the ground state but it also correctly responds to the large change in the solute electronic charge distribution upon excitation.

  7. 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

  8. State-selective electron capture in collisions of ground and metastable O{sup 2+} ions with H(1s)

    Energy Technology Data Exchange (ETDEWEB)

    Cabello, C N [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Errea, L F [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Fernandez, L [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Mendez, L [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Macias, A [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Rabadan, I [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Riera, A [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain)

    2003-01-28

    An ab initio calculation of the electron capture cross sections for collisions of ground and metastable states of O{sup 2+} with H(1s) is presented. For impact energies between 0.125 and 3.4 keV amu{sup -1}, we find good agreement between the cross sections from the ground state ion with the mixed beam experimental data of Phaneuf et al (Phaneuf A, Alvarez I, Meyer F W and Crandall D H 1982 Phys. Rev. A 26 1892)

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. Effect of near-earth thunderstorms electric field on the intensity of ground cosmic ray positrons/electrons in Tibet

    Science.gov (United States)

    Zhou, X. X.; Wang, X. J.; Huang, D. H.; Jia, H. Y.

    2016-11-01

    Monte Carlo simulations are performed to study the correlation between the ground cosmic ray intensity and near-earth thunderstorms electric field at YBJ (located at YangBaJing, Tibet, China, 4300 m a. s. l.). The variations of the secondary cosmic ray intensity are found to be highly dependent on the strength and polarity of the electric field. In negative fields and in positive fields greater than 600 V/cm, the total number of ground comic ray positrons and electrons increases with increasing electric field strength. And these values increase more obviously when involving a shower with lower primary energy or a higher zenith angle. While in positive fields ranging from 0 to 600 V/cm, the total number of ground comic ray positrons and electrons declines and the amplitude is up to 3.1% for vertical showers. A decrease of intensity occurs in inclined showers within the range of 0-500 V/cm, which is accompanied by smaller amplitudes. In this paper, the intensity changes are analyzed, especially concerning those decreasing phenomena in positive electric fields. Our simulation results could be helpful in understanding the decreases observed in some ground-based experiments (such as the Carpet air shower array and ARGO-YBJ), and also be useful in understanding the acceleration mechanisms of secondary charged particles caused by an atmospheric electric field.

  14. Permanent Electron Electric Dipole Moment Search in the X^3Δ_1 Ground State of Tungsten Carbide Molecules

    Science.gov (United States)

    Lee, Jeongwon; Chen, Jinhai; Leanhardt, Aaron

    2011-06-01

    We are developing an experiment to search for the permanent electric dipole moment (EDM) of the electron using the valence electrons in the X^3Δ_1 ground state of Tungsten Carbide (WC) molecules. Currently, we are detecting the molecules by Laser Induced Fluorescence spectroscopy at ˜75cm downstream of a pulsed ablation beam source. We have a detection rate of ˜10 182W12C molecules/second in X^3Δ_1, v"=0, J"=1 state with geometric detection efficiency of 0.004. A continuous WC molecular beam is under development. Additionally, preliminary measurements of the 183W12C hyperfine structure will be presented.

  15. Electronics Principles Avionics Aerospace Ground Equipment (AGE) Career Ladder AFSCS 326X0A, B, C, D.

    Science.gov (United States)

    1976-12-27

    This report summarizes the results of the administration of the Electronics Principles survey to airmen assigned to the Avionics Aerospace Ground Equipment (AGE) specialties, including 326XOA, Manually Operated Avionics AGE; 326XOB, Automatic Avionics AGE; 326XOC, F/RF-4 Peculiar AGE, and 326XOD, A-7D Avionics AGE. The report gives a detailed listing of the technical tasks and knowledge needed to

  16. Coupled Cluster Calculations of the Ground and Excited Electronic States Using Two- and Four-Component Relativistic Spinors

    Directory of Open Access Journals (Sweden)

    Rajat K. Chaudhuri

    2003-12-01

    Full Text Available Abstract: The coupled cluster based linear response theory which is applicable to the direct calculation of atomic and molecular properties are presented and applied to compute the ionization potentials and excitation energies of light and moderately heavy atoms. The e®ect of electron correlation on the ground and excited states is studied using Hartree-Fock, Dirac-Fock and approximate two-component relativistic spinors.

  17. Selective excitation of a vibrational level within the electronic ground state of a polyatomic molecule with ultra pulses

    CSIR Research Space (South Africa)

    de Clercq, L

    2010-09-01

    Full Text Available of a Vibrational Level Within the Electronic Ground State of a Polyatomic Molecule with Ultra Short Pulses Ludwig de Clercq1,2, Lourens Botha1,2, Hermann Uys1, Anton Du Plessis1,2, Erich Rohwer2 1CSIR National Laser Centre, PO BOX 395, Pretoria... al lbl d i I e I e dt ? , )? ? ? ? ?=?= ??h (1) where, , .a b a b? ? ?= ? , (2) ?ab gives the elements of the density matrix, ?a the frequencies...

  18. Mutual Co-Assignment of the Calculated Vibrational Frequencies in the Ground and Lowest Excited Electronic States

    Science.gov (United States)

    Panchenko, Yurii N.

    2013-06-01

    The shifts of the molecular vibrational frequencies when going from the ground electronic state to the lowest excited electronic states pose some problems for the mutual co-assignment of the calculated vibrational frequencies in the different excited states. The trans-{C_2 O_2 F_2} shift of the frequency of the symmetrical ν(C=O) stretching vibration between the S_0 and T_1 is 373 wn. The feasibility of mutual co-assignments of the vibrational frequencies in these electronic states has been demonstrated for trans-{C_2 O_2 F_2}. Matrices analogous to the Duschinsky matrix were used to juxtapose the a_g vibrational frequencies of this molecule calculated at the CASPT2/cc-pVTZ level in the ground S_0 and excited triplet T_1 and singlet S_1 electronic states. The analog of the Duschinsky matrix D was obtained for this molecule using the equation D = (L_{I})^{-1} L_{II} where L_{I} and L_{II} are the matrices of the vibrational modes (normalized atomic displacements) obtained by solving the vibrational problems for the S_0 and T_1 electronic states, respectively. Choosing the dominant elements in columns of the D matrix and permuting these columns to arrange these elements along the diagonal of the transformed matrix D^* makes it possible to establish the correct mutual co-assignments of the calculated a_g vibrational frequencies of the trans-{C_2 O_2 F_2} molecule in the S_0 and T_1 electronic states. The analogous procedure was performed for the trans-{C_2 O_2 F_2} molecule in the T_1 and S_1 excited electronic states. The recent reassignments of the νb{2} and νb{3} calculated vibrational frequencies in the trans-{C_2 O_2 F_2} molecule in the ground state were also obtained for the triplet T_1 and singlet S_1 excited electronic states. The approach set forth in this text makes it possible to juxtapose the calculated vibrational frequencies of the same molecule in the different electronic states and to refine the assignments of these frequencies. This is essential

  19. 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

  20. Many-body Green’s function theory for electron-phonon interactions: Ground state properties of the Holstein dimer

    Energy Technology Data Exchange (ETDEWEB)

    Säkkinen, Niko; Leeuwen, Robert van [Department of Physics, Nanoscience Center, University of Jyväskylä, Survontie 9, 40014 Jyväskylä (Finland); Peng, Yang [Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin, 14195 Berlin (Germany); Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin-Dahlem (Germany); Appel, Heiko [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin-Dahlem (Germany)

    2015-12-21

    We study ground-state properties of a two-site, two-electron Holstein model describing two molecules coupled indirectly via electron-phonon interaction by using both exact diagonalization and self-consistent diagrammatic many-body perturbation theory. The Hartree and self-consistent Born approximations used in the present work are studied at different levels of self-consistency. The governing equations are shown to exhibit multiple solutions when the electron-phonon interaction is sufficiently strong, whereas at smaller interactions, only a single solution is found. The additional solutions at larger electron-phonon couplings correspond to symmetry-broken states with inhomogeneous electron densities. A comparison to exact results indicates that this symmetry breaking is strongly correlated with the formation of a bipolaron state in which the two electrons prefer to reside on the same molecule. The results further show that the Hartree and partially self-consistent Born solutions obtained by enforcing symmetry do not compare well with exact energetics, while the fully self-consistent Born approximation improves the qualitative and quantitative agreement with exact results in the same symmetric case. This together with a presented natural occupation number analysis supports the conclusion that the fully self-consistent approximation describes partially the bipolaron crossover. These results contribute to better understanding how these approximations cope with the strong localizing effect of the electron-phonon interaction.

  1. Calculation of Ground State Rotational Populations for Kinetic Gas Homonuclear Diatomic Molecules including Electron-Impact Excitation and Wall Collisions

    Energy Technology Data Exchange (ETDEWEB)

    David R. Farley

    2010-08-19

    A model has been developed to calculate the ground-state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow of feed gas and equilibrating wall collisions can significantly affect the rotational distribution in competition with non-equilibrating electron-impact effects. The resulting steady-state rotational distributions are generally Boltzmann for N≥3, with a rotational temperature between the wall and feed gas temperatures. The N=0,1,2 rotational level populations depend sensitively on the relative rates of electron-impact excitation versus wall collision and gas feed rates.

  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. 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.

  4. Effect of near-earth thunderstorms electric field on the intensity of ground cosmic ray positrons/electrons in Tibet

    CERN Document Server

    Zhou, X X; Huang, D H; Jia, H Y

    2016-01-01

    Monte Carlo simulations are performed to study the correlation between the ground cosmic ray intensity and near-earth thunderstorms electric field at YBJ (4300 m a.s.l., Tibet, China). The variations of the secondary cosmic ray intensity are found to be highly dependent on the strength and polarity of the electric field. In negative fields and in positive fields greater than 600 V/cm, the total number of ground comic ray positrons and electrons increases with increasing electric field strength. And these values increase more obviously when involving a shower with lower primary energy or a higher zenith angle. While in positive fields ranging from 0 to 600 V/cm, the total number of ground comic ray positrons and electrons declines and the amplitude is up to 3.1% for vertical showers. A decrease of intensity occurs for inclined showers in positive fields less than 500 V/cm, which is accompanied by smaller amplitudes. In this paper, the intensity changes are discussed, especially concerning the decreases in posi...

  5. Comparison of the characteristic energy of precipitating electrons derived from ground-based and DMSP satellite data

    Directory of Open Access Journals (Sweden)

    M. Ashrafi

    2005-01-01

    Full Text Available Energy maps are important for ionosphere-magnetosphere coupling studies, because quantitative determination of field-aligned currents requires knowledge of the conductances and their spatial gradients. By combining imaging riometer absorption and all-sky auroral optical data it is possible to produce high temporal and spatial resolution maps of the Maxwellian characteristic energy of precipitating electrons within a 240240 common field of view. These data have been calibrated by inverting EISCAT electron density profiles into equivalent energy spectra. In this paper energy maps produced by ground-based instruments (optical and riometer are compared with DMSP satellite data during geomagnetic conjunctions. For the period 1995-2002, twelve satellite passes over the ground-based instruments' field of view for the cloud-free conditions have been considered. Four of the satellite conjunctions occurred during moderate geomagnetic, steady-state conditions and without any ion precipitation. In these cases with Maxwellian satellite spectra, there is 71% agreement between the characteristic energies derived from the satellite and the ground-based energy map method.

  6. The influence of f-electron hopping on ground states and valence transitions in the extended Falicov-Kimball model

    Science.gov (United States)

    Farkašovský, Pavol; Čenčariková, Hana

    2014-09-01

    The ground-state phase diagram of the extended Falicov-Kimball model with f- f electron hopping is studied numerically in the one-dimensional case. To identify the nature of ground states three complementary numerical methods are used, and namely, (i) the small-cluster exact-diagonalization method, (ii) the density-matrix-renormalization-group method (DMRG) and (iii) an approximate, but very accurate, numerical method based on the reduction of the Hilbert space. It is found that the physics of the Falicov-Kimball model found for the zero value of the f-electron hopping integral t f (including the existence of the devil's staircase structure) persists also at finite values of t f . The critical values of t c f below which the physics of the Falicov-Kimball model dominates are calculated numerically and it is shown that they depend very strongly on the f-electron concentration n f and only very weakly on the Coulomb interaction. In particular, we have found that for strong Coulomb interactions the value of t c f rapidly increases from t c f ~ 0.003 found for n f = 1 / 4 up to relatively large t c f ~ 0.4 found for n f near the half-filled band case n f = 1 / 2. In addition, the complete picture of valence transitions is presented for non-zero t f and strong Coulomb interactions.

  7. Global Three-Dimensional Ionospheric Data Assimilation Model Using Ground-based GPS and Radio Occultation Total Electron Content

    Science.gov (United States)

    Jann-Yenq Liu, Tiger; Lin, Chi-Yen; Matsuo, Tomoko; Lin, Charles C. H.; Tsai, Ho-Fang; Chen, Chao-Yen

    2017-04-01

    An ionospheric data assimilation approach presented here is based on the Gauss-Markov Kalman filter with International Reference Ionosphere (IRI) as the background model and designed to assimilate the total electron content (TEC) observed from ground-based GPS receivers and space-based radio occultation (RO) of FORMOSAT-3/COSMIC (F3/C) or FORMOSAT-7/COSMIC-2 (F7/C2). The Kalman filter consists of the forecast step according to Gauss-Markov process and measurement update step. Observing System Simulation Experiments (OSSEs) show that the Gauss-Markov Kalman filter procedure can increase the accuracy of the data assimilation analysis over the procedure consisting of the measurement update step alone. Moreover, in comparing to F3/C, the dense F7/C2 RO observation can further increase the model accuracy significantly. Validating the data assimilation results with the vertical TEC in Global Ionosphere Maps and that derived from ground-based GPS measurements, as well as the ionospheric F2-peak height and electron density sounded by ionosondes is also carried out. Both the OSSE results and the observation validations confirm that the developed data assimilation model can be used to reconstruct the three-dimensional electron density in the ionosphere satisfactorily.

  8. Comparison of Quality of Bologna Sausage Manufactured by Electron Beam or X-Ray Irradiated Ground Pork.

    Science.gov (United States)

    Shin, Mee-Hye; Lee, Ju-Woon; Yoon, Young-Min; Kim, Jong Heon; Moon, Byeong-Geum; Kim, Jae-Hun; Song, Beom-Suk

    2014-01-01

    Ground lean pork was irradiated by an electron beam or X-rays to compare the effects of two types of radiation generated by a linear accelerator on the quality of Bologna sausage as a model meat product. Raw ground lean pork was vacuum packaged at a thickness of 1.5 cm and irradiated at doses of 2, 4, 6, 8, or 10 kGy by an electron beam (2.5 MeV) or X-rays (5 MeV). Solubility of myofibrillar proteins, bacterial counts, and thiobarbituric acid reactive substance (TBARS) values were determined for raw meat samples. Bologna sausage was manufactured using the irradiated lean pork, and total bacterial counts, TBARS values, and quality properties (color differences, cooking yield, texture, and palatability) were determined. Irradiation increased the solubility of myofibrillar proteins in a dose-dependent manner (p<0.05). Bacterial contamination of the raw meat was reduced as the absorbed dose increased, and the reduction was the same for both radiation types. Differences were observed only between irradiated and non-irradiated samples (p<0.05). X-ray irradiation may serve as an alternative to gamma irradiation and electron beam irradiation.

  9. 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.

  10. R-matrix calculation of differential cross sections for low-energy electron collisions with ground and electronically excited state O2 molecules

    CERN Document Server

    Tashiro, M; Tennyson, J; Tashiro, Motomichi; Morokuma, Keiji; Tennyson, Jonathan

    2006-01-01

    Differential cross sections for electron collisions with the O$_2$ molecule in its ground ${X}^{3}\\Sigma_g^-$ state, as well as excited ${a}^{1}\\Delta_g$ and ${b}^{1}\\Sigma_g^+$ states are calculated. As previously, the fixed-bond R-matrix method based on state-averaged complete active space SCF orbitals is employed. In additions to elastic scattering of electron with the O$_2$ ${X}^{3}\\Sigma_g^-$, ${a}^{1}\\Delta_g$ and ${b}^{1}\\Sigma_g^+$ states, electron impact excitation from the ${X}^{3}\\Sigma_g^-$ state to the ${a}^{1}\\Delta_g$ and ${b}^{1}\\Sigma_g^+$ states as well as '6 eV states' of ${c}^{1}\\Sigma_u^{-}$, ${A'}^{3}\\Delta_u$ and ${A}^{3}\\Sigma_u^{+}$ states is studied. Differential cross sections for excitation to the '6 eV states' have not been calculated previously. Electron impact excitation to the ${b}^{1}\\Sigma_g^+$ state from the metastable ${a}^{1}\\Delta_g$ state is also studied. For electron impact excitation from the O$_2$ ${X}^{3}\\Sigma_g^-$ state to the ${b}^{1}\\Sigma_g^+$ state, our results...

  11. Influence of the injected charge polarity on the electrical behavior of CMX 100-AR cover glass submitted to electron irradiation

    OpenAIRE

    Belhaj, M.; Paulmier, T.; Guibert, N.; Payan, D.; Balcon, N.

    2014-01-01

    International audience; Under electron irradiation, insulating materials may charge either negatively or positively depending on their electron emission properties and characteristics of the incident electrons. The electrical behavior of these materials is linked to the sign of the injected charge. Some spacecraft materials may be subject is some situations to negative charging and in other situations to positive charging. The aim of this work is to investigate the effect of the sign of the i...

  12. Vibrational Spectra and Potential Energy Surface for Electronic Ground State of Jet-Cooled Molecule S2O

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Yan; DING Shi-Liang

    2004-01-01

    The vibration states of transition molecule S2O, including both bending and stretching vibrations, are studied in the framework of dynamical symmetry groups U1(4) U2(4). We get all the vibration spectra of S2O by fitting 22 spectra data with 10 parameters. The fitting rms of the Hamiltonian is 2.12 cm-1. With the parameters and Lie algebraic theory, we give the analytical expression of the potential energy surface, which helps us to calculate the dissociation energy and force constants of S2O in the electronic ground state.

  13. Unification of ground-state aromaticity criteria - structure, electron delocalization, and energy - in light of the quantum chemical topology.

    Science.gov (United States)

    Badri, Zahra; Foroutan-Nejad, Cina

    2016-04-28

    In the present account we investigate a theoretical link between the bond length, electron sharing, and bond energy within the context of quantum chemical topology theories. The aromatic stabilization energy, ASE, was estimated from this theoretical link without using isodesmic reactions for the first time. The ASE values obtained from our method show a meaningful correlation with the number of electrons contributing to the aromaticity. This theoretical link demonstrates that structural, electronic, and energetic criteria of aromaticity - ground-state aromaticity - belong to the same class and guarantees that they assess the same property as aromaticity. Theory suggests that interatomic exchange-correlation potential, obtained from the theory of Interacting Quantum Atoms (IQA), is linearly connected to the delocalization index of Quantum Theory of Atoms in Molecules (QTAIM) and the bond length through a first order approximation. Our study shows that the relationship between energy, structure and electron sharing marginally deviates from the ideal linear form expected from the first order approximation. The observed deviation from linearity was attributed to a different contribution of exchange-correlation to the bond energy for the σ- and π-frameworks. Finally, we proposed two-dimensional energy-structure-based aromaticity indices in analogy to the electron sharing indices of aromaticity.

  14. Ground state of the quasi-1D correlated electronic system BaVS{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Foury-Leylekian, Pascale, E-mail: pascale.foury@u-psud.fr [Laboratoire de Physique des Solides, UMR 8502, CNRS, Universite Paris-Sud, F- 91405, Orsay Cedex (France); Leininger, Philippe [Max-Planck-Insitut furFestkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Ilakovac, Vita [LCP-MR, Universite Pierre et Marie Curie, UMR 7614, CNRS, F-75321 Paris, France and Universite Cergy-Pontoise, F-95031, Cergy-Pontoise (France); Joly, Yves [Institut Neel, CNRS-UJF, BP 166, F-38042 Grenoble Cedex 9 (France); Bernu, Sylvain; Fagot, Sebastien; Pouget, Jean-Paul [Laboratoire de Physique des Solides, UMR 8502, CNRS, Universite Paris-Sud, F- 91405, Orsay Cedex (France)

    2012-06-01

    In this paper we review the salient features of the different instabilities exhibited by the quasi-1D system BaVS{sub 3} and show that there is a subtle interplay between the different phases stabilized. The analysis of the Peierls instability shows that the mobile dz Superscript-Two electrons are more localized than calculated because of their strong correlation with the localized e(t{sub 2g}) electrons. The complex AF magnetic structure of BaVS{sub 3} incorporates the magnetization of the e(t{sub 2g}) electrons with the Peierls pairing of the dz Superscript-Two electrons into magnetic singlets. Finally, we propose that the zig-zag disorder remaining after an incomplete orthorhombic phase transition could change the sign of the magnetic coupling and thus help to stabilize the canted ferromagnetism observed in non stoichiometric BaVS{sub 3-{delta}} and Sr and Ba substituted compounds.

  15. 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...

  16. 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...

  17. Ground-water-quality data in Pennsylvania: A compilation of computerized [electronic] databases, 1979-2004

    Science.gov (United States)

    Low, Dennis J.; Chichester, Douglas C.

    2006-01-01

    This study, by the U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Environmental Protection (PADEP), provides a compilation of ground-water-quality data for a 25-year period (January 1, 1979, through August 11, 2004) based on water samples from wells. The data are from eight source agencies唯orough of Carroll Valley, Chester County Health Department, Pennsylvania Department of Environmental Protection-Ambient and Fixed Station Network, Montgomery County Health Department, Pennsylvania Drinking Water Information System, Pennsylvania Department of Agriculture, Susquehanna River Basin Commission, and the U.S. Geological Survey. The ground-water-quality data from the different source agencies varied in type and number of analyses; however, the analyses are represented by 12 major analyte groups:biological (bacteria and viruses), fungicides, herbicides, insecticides, major ions, minor ions (including trace elements), nutrients (dominantly nitrate and nitrite as nitrogen), pesticides, radiochemicals (dominantly radon or radium), volatile organic compounds, wastewater compounds, and water characteristics (dominantly field pH, field specific conductance, and hardness).A summary map shows the areal distribution of wells with ground-water-quality data statewide and by major watersheds and source agency. Maps of 35 watersheds within Pennsylvania are used to display the areal distribution of water-quality information. Additional maps emphasize the areal distribution with respect to 13 major geolithologic units in Pennsylvania and concentration ranges of nitrate (as nitrogen). Summary data tables by source agency provide information on the number of wells and samples collected for each of the 35 watersheds and analyte groups. The number of wells sampled for ground-water-quality data varies considerably across Pennsylvania. Of the 8,012 wells sampled, the greatest concentration of wells are in the southeast (Berks, Bucks, Chester, Delaware

  18. Nuclear orientation of 144Pm in the electronic singlet ground state system PrIn 3

    Science.gov (United States)

    Vermeulen, G. A.; Greidanus, F. J. A. M.; Hunik, R.; Huiskamp, W. J.

    1980-04-01

    The gamma-ray anisotropy of 144Pm in the Van Vleck paramagnet PrIn 3 is investigated both theoretically and experimentally. A simple model, which accounts for the essential experimental features is proposed. The purpose of this model is to extract the exchange interaction between the Pm ion and its nearest Pr neighbours and the crystal field splitting of the Pm ions. Both, the Pr and Pm ions have non-magnetic ground states in which magnetism is induced by external magnetic fields. Therefore, the interaction between the external magnetic field and the Pm nuclei is enhanced. We find an enhancement factor, к = 220. This enhancement is mainly induced by exchange interactions and for fields larger than 0.5 T there are already strong non-linear effects.

  19. 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.

  20. Inelastic electron tunneling through degenerate and nondegenerate ground state polymeric junctions

    Energy Technology Data Exchange (ETDEWEB)

    Golsanamlou, Z.; Bagheri Tagani, M., E-mail: m_bagheri@guilan.ac.ir; Rahimpour Soleimani, H.

    2015-05-01

    Highlights: • Current–voltage characteristics of two polymeric junctions are studied. • Current is reduced in phonon assistant tunneling regime. • Behavior of current is independent of temperature. • Elastic energy changes current drastically. - Abstract: The inelastic electron transport properties through two polymeric (trans-polyacetylene and polythiophene) molecular junctions are studied using Keldysh nonequilibrium Green function formalism. The Hamiltonian of the polymers is described via Su–Schrieffer–Heeger model and the metallic electrodes are modeled by the wide-band approximation. Results show that the step-like behavior of the current–voltage characteristics is deformed in presence of strong electron–phonon interaction. Also, the magnitude of current is slightly decreased in the phonon assistant electron transport regime. In addition, it is observed that the I–V curves are independent of temperature.

  1. Towards producing ultracold CaNa+ molecular ions in the ground electronic state

    Science.gov (United States)

    Gacesa, Marko; Montgomery, John A.; Michels, Harvey H.; Côté, Robin

    2015-05-01

    We present a theoretical analysis of optical pathways for the formation of cold Ca(1S)Na+(1S) molecular ions, based on accurate potential energy curves and transition dipole moments calculated using effective-core-potential methods of quantum chemistry. In the proposed approach, starting from a mixture of trapped laser-cooled Ca+ ions immersed into an ultracold gas of Na atoms, the (NaCa)+ are photoassociated in the excited E1Σ+ electronic state, followed by spontaneous radiative charge transfer and emission through an intermediate state. We find the optimal formation pathway and report radiative charge-exchange cross sections and vibrational distributions of participating electronic states. This work is partially supported by ARO.

  2. Be(1010): A test ground for surface electron-phonon coupling

    Science.gov (United States)

    Tang, Shu-Jung; Sprunger, Philip; Plummer, Ward; Yang, Wanli; Brouet, Veronique; Zhou, Xingjiang; Shen, Zhi-Xun

    2003-03-01

    The electron-phonon coupling on the Be(10bar10) surface has been investigated with high-resolution photoemission examining temperature dependence and dispersion distortion near the Fermi energy of the two zone boundary surface states. Two surface states (S1 and S2) coexist in a large gap in the bulk projection at the surface zone boundary barA. S1 is localized near the surface in the middle of the gap while S2 is near the bottom band edge and penetrates into the bulk. Using both a Debye and Einstein model to fit the temperature-dependent surface state line width produces an electron-phonon coupling strength with parameters, λ _S1 = 0.647 and λ _S2 = 0.491, more than two times larger than the bulk value, λ _bulk = 0.24. S2 data was measured with a 3D Debye model but the S1 data required an Einstein model with an optical phonon at energy 64 meV. Direct 2D images of the dispersion of the S1 state show dramatic distortion of the electron band dispersion within 64 meV of the Fermi energy. This data is used to extract the real and imaginary parts of the self-energy. Founded by NSF DMR-0105232 and Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under contract DE-AC05-00OR22725

  3. Electronic ground state OH(X) radical in a low-temperature atmospheric pressure plasma jet

    Science.gov (United States)

    Fuh, Che A.; Clark, Shane M.; Wu, Wei; Wang, Chuji

    2016-10-01

    The wide applicability of atmospheric pressure plasma jets in biomedicine stems from the presence of reactive nitrogen and oxygen species generated in these plasma jets. Knowing the absolute concentration of these reactive species is of utmost importance as it is critical, along with the particle flux obtained from the plasma feed gas flow rate to ensure that the correct dosage is applied during applications. In this study, we investigate and report the ground state OH(X) number density acquired using cavity ringdown spectroscopy, along the propagation axis (z-axis) of a cold atmospheric pressure helium plasma plume. The jet was generated by a repetitively pulsed mono-polar square wave of duration 1 μs running at a frequency of 9.9 kHz. The voltage supplied was 6.5 kV with the helium flow rate fixed at 3.6 standard liters per minute. The rotational and vibrational temperatures are simulated from the second positive system of nitrogen, N 2(C3πu-B3πg) , with the rotational temperature being spatially constant at 300 K along the propagation axis of the atmospheric pressure plasma jet while the vibrational temperature is 3620 K at the beginning of the plume and is observed to decrease downstream. The OH(A) emission intensity obtained via optical emission spectroscopy was observed to decrease downstream of the plasma jet. The OH(X) number density along the propagation axis was initially 2.2 × 1013 molecules cm-3 before increasing to a peak value of 2.4 × 1013 molecules cm-3, from which the number density was observed to decrease to 2.2 × 1013 molecules cm-3 downstream of the plasma jet. The total OH(A, X) in the plasma jet remained relatively constant along the propagation axis of the plasma jet before falling off at the tip of the jet. The increase in vibrational temperature downstream and the simultaneous measurements of both the excited state OH(A) and the ground state OH(X) reported in this study provide insights into the formation and consumption of this

  4. Spin of the ground quantum state of electrons from first principles in the representation of Feynman path integrals

    Science.gov (United States)

    Shevkunov, S. V.

    2016-08-01

    A method for calculating the spin of the ground quantum state of nonrelativistic electrons and distance between energy levels of quantum states differing in the spin magnitude from first principles is proposed. The approach developed is free from the one-electron approximation and applicable in multielectron systems with allowance for all spatial correlations. The possibilities of the method are demonstrated by the example of calculating the energy gap between spin states in model ellipsoidal quantum dots with a harmonic confining field. The results of computations by the Monte Carlo method point to high sensitivity of the energy gap to the break of spherical symmetry of the quantum dot. For three electrons, the phenomenon of inversion has been revealed for levels corresponding to high and low values of the spin. The calculations demonstrate the practical possibility to obtain spin states with arbitrarily close energies by varying the shape of the quantum dot, which is a key condition for development prospects in technologies of storage systems based on spin qubits.

  5. Peierls ground state and excitations in the electron-lattice correlated system (EDO-TTF)2X

    Science.gov (United States)

    Tsuchiizu, M.; Suzumura, Y.

    2008-05-01

    We investigate the exotic Peierls state in the one-dimensional organic compound (EDO-TTF)2X , wherein the Peierls transition is accompanied by the bending of molecules and also by a fourfold periodic array of charge disproportionation along the one-dimensional chain. Such a Peierls state, wherein the interplay between the electron correlation and the electron-phonon interaction takes an important role, is examined based on an extended Peierls Holstein Hubbard model that includes the alternation of the elastic energies for both the lattice distortion and the molecular deformation. The model reproduces the experimentally observed pattern of the charge disproportionation and there exists a metastable state wherein the energy takes a local minimum with respect to the lattice distortion and/or molecular deformation. Furthermore, we investigate the excited states for both the Peierls ground state and the metastable state by considering the soliton formation of electrons. It is shown that the soliton excitation from the metastable state costs energy that is much smaller than that of the Peierls state, where the former is followed only by the charge degree of freedom and the latter is followed by that of spin and charge. Based on these results, we discuss the exotic photoinduced phase found in (EDO-TTF)2PF6 .

  6. 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.

  7. 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.

  8. 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.

  9. Enhancement of Natural Convection by Carbon Nanotube Films Covered Microchannel-Surface for Passive Electronic Cooling Devices.

    Science.gov (United States)

    Zhang, Guang; Jiang, Shaohui; Yao, Wei; Liu, Changhong

    2016-11-16

    Owing to the outstanding properties of thermal conduction, lightweight, and chemical durability, carbon nanotubes (CNTs) have revealed promising applications in thermal management materials. Meanwhile, the increasingly popular portable electronics and the rapid development of space technology need lighter weight, smaller size, and more effective thermal management devices. Here, a novel kind of heat dissipation devices based on the superaligned CNT films and underlying microchannels is proposed, and the heat dissipation properties are measured at the natural condition. Distinctive from previous studies, by combining the advantages of microchannels and CNTs, such a novel heat dissipation device enables superior natural convection heat transfer properties. Our findings prove that the novel CNT-based devices could show an 86.6% larger total natural heat dissipation properties than bare copper plate. Further calculations of the radiation and natural convection heat transfer properties demonstrate that the excellent passive cooling properties of these CNT-based devices are primarily caused by the reinforcement of the natural convection heat transfer properties. Furthermore, the heat dissipation mechanisms are briefly discussed, and we propose that the very high heat transfer coefficients and the porous structures of superaligned CNT films play critical roles in reinforcing the natural convection. The novel CNT-based heat dissipation devices also have advantages of energy-saving, free-noise, and without additional accessories. So we believe that the CNT-based heat dissipation devices would replace the traditional metal-finned heat dissipation devices and have promising applications in electronic devices, such as photovoltaic devices, portable electronic devices, and electronic displays.

  10. 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.

  11. 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

  12. Potential function of the internal rotation of a methacrolein molecule in the ground ( S 0) electronic state

    Science.gov (United States)

    Koroleva, L. A.; Krasnoshchekov, S. V.; Matveev, V. K.; Pentin, Yu. A.

    2016-08-01

    The structural parameters of s- trans- and s- cis-isomers of a methacrolein molecule in the ground ( S 0) electronic state are determined by means of MP2 method with the cc-pVTZ basis set. Kinematic factor F(φ) is expanded in a Fourier series. The potential function of internal rotation (PFIR) of methacrolein in this state is built using experimental frequencies of transitions of the torsional vibration of both isomers, obtained from an analysis of the vibrational structure of the high-resolution UV spectrum with allowance for the geometry and difference between the energy (Δ H) of the isomers. It is shown that the V n parameters of the potential function of internal rotation of the molecule, built using the frequencies of the transition of the torsional vibrations of s- trans- and s- cis-isomers of the methacrolein molecule, determined from vibrational structure of the high-resolution UV spectrum and the FTIR spectrum, are close.

  13. Forbidden Electronic Transitions between the Singlet Ground State and the Triplet Excited State of Pt(II) Complexes.

    Science.gov (United States)

    Zheng, Greg Y.; Rillema, D. Paul; DePriest, Jeff; Woods, Clifton

    1998-07-13

    Direct access to the triplet emitting state from the ground state is observed for Pt(II) complexes containing heterocyclic (CwedgeC', CwedgeN, NwedgeN') and bis(diphenylphosphino)alkane (PwedgeP') ligands. Extinction coefficients for such transitions are in the range 4-25 M(-)(1) cm(-)(1). Emission quantum yields resulting from singlet-to-triplet excitation are as high as 61-77 times the emission quantum yields resulting from singlet-to-singlet excitation at 296 K. The intersystem crossing quantum yield from the singlet excited state to triplet emitting state is lower than 2% at 296 K but is greatly enhanced at 77 K. The forbidden electronic transition observed for Pt(II) complexes is attributed to result from spin-orbit coupling due to the presence of Pt(II) in the skeleton structure. The importance of excitation spectra on the computation of emission quantum yields is discussed.

  14. Accurate internuclear potential energy functions for the ground electronic states of NeH+ and ArH+

    Science.gov (United States)

    Coxon, John A.; Hajigeorgiou, Photos G.

    2016-12-01

    All pure rotational and vibrational-rotational spectroscopic line positions available on the ground X1Σ+ electronic states of the rare gas hydride cations NeH+ and ArH+ have been employed in weighted least-squares direct fits to the potential energy functions, together with auxiliary functions describing breakdown of the Born-Oppenheimer approximation. All radial functions are represented by compact analytical models, and the spectroscopic line positions are reproduced to within the associated experimental uncertainties by the quantum-mechanical eigenvalues of the derived Hamiltonians. The potential energy functions are constrained to approach the theoretical radial behavior at long-range. Accurate vibrational term values and rotational and centrifugal distortion constants are provided for all stable isotopologues of NeH+ and ArH+ included in the least-squares fits.

  15. Vibrational assignment and vibronic interaction for NO3 in the ground electronic state

    Science.gov (United States)

    Hirota, Eizi

    2015-04-01

    Two important problems exist for the NO3 free radical. One is the frequency of the degenerate N-O stretching mode ν3. It has been assigned to a band at 1492 cm-1 (Assignment I), whereas Stanton calculated it by an ab initio MO method to be around 1000 cm-1 (Assignment II). The second concerns an anomalous ν4 progression, which appeared in the photoelectron spectra of the NO3 anion and was accounted for by Herzberg-Teller (H-T) mechanism, but the interaction parameter derived was too large. The present study critically examines Assignment II and the H-T vibronic interaction model against the results of high-resolution infrared (IR) spectroscopy supplemented with dispersed fluorescence (DF), and concludes Assignment I to be correct and the H-T mechanism to be complemented by a new vibronic interaction model, based upon the observations: (1) Stanton's ab initio MO ν3 appeared in neither IR nor DF spectra, (2) only one A-E type subband was present in the Z-ν4 hot band (Z denotes the upper state of the 1492 cm-1 band), at variance with the two predicted by Assignment II, (3) the ℓ-type doubling constant and the first-order Coriolis coupling constant derived for the Z state by assuming Assignment II were not acceptable, and (4) anomalous features expected from the H-T vibronic interaction model for the ν4 fundamental state were not observed at all. Infrared spectroscopic results on a few 2E‧ degenerate states indicated that the first-order Coriolis coupling constant and the effective spin-orbit interaction constant were closely correlated, suggesting that the unpaired electron azimuthal motion was affected much by that of the degenerate vibrational mode. This sort of vibronic interaction has been well known for linear polyatomic free radicals in 2Σ electronic states with a bending mode singly excited. A similar vibronic interaction should be present also in symmetric-top free radicals, where a degenerate vibrational mode is singly excited. However, few examples

  16. Electronic Circuit Experiments and SPICE Simulation of Double Covering Bifurcation of 2-Torus Quasi-Periodic Flow in Phase-Locked Loop Circuit

    Science.gov (United States)

    Kamiyama, Kyohei; Endo, Tetsuro; Imai, Isao; Komuro, Motomasa

    2016-06-01

    Double covering (DC) bifurcation of a 2-torus quasi-periodic flow in a phase-locked loop circuit was experimentally investigated using an electronic circuit and via SPICE simulation; in the circuit, the input radio-frequency signal was frequency modulated by the sum of two asynchronous sinusoidal baseband signals. We observed both DC and period-doubling bifurcations of a discrete map on two Poincaré sections, which were realized by changing the sample timing from one baseband sinusoidal signal to the other. The results confirm the DC bifurcation of the original flow.

  17. 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.

  18. Electronic states on the clean and oxygen-covered molybdenum (110) surface measured using time-of-flight momentum microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chernov, Sergii

    2016-04-20

    Recent experiments discovered a new class of materials called topological insulators and started an extensive investigation in order to find more materials of such type and to understand and explore the opening perspectives in fundamental science and application. These materials exhibit a Dirac-type (massless) electronic state, bridging the fundamental band gap. Surprisingly, a strongly spin-polarized surface state with linear dispersion resembling that of Dirac type was found on the already well-investigated W(110) surface. This rose the question of the existence of the same non-trivial electron state on other metal surfaces. The present work describes the investigation of surface electronic states on the Mo(110) surface, their dispersion and transformation upon surface oxidation. This system is isoelectronic to the case of W(110) but due to the lower atomic number the spin-orbit interaction responsible for local band gap formation is substantially decreased by a factor of 5. The Mo(110) surface was shown to exhibit a linearly dispersing state quite similar to the one on W(110), but within a smaller energy range of 120 meV, with the Dirac point lying in the center of a local band gap in k-space. The experimental investigations were performed with the help of momentum microscopy, using a Ti:sapphire laser in the lab and synchrotron radiation at BESSY II, Berlin. The results show good agreement with theoretical calculations of the band structure and photoemission patterns for clean Mo(110). The fully parallel 3D acquisition scheme allowed to visualize the full surface Brillouin zone of the sample up to few eV binding energy within a single exposure of typically less than 30 min. This opens the door to future time-resolved experiments with maximum detection efficiency.

  19. Water resistance and surface morphology of synthetic fabrics covered by polysiloxane/acrylate followed by electron beam irradiation

    CERN Document Server

    El-Naggar, A M; Mohammed, S S; Alam, E A

    2003-01-01

    Different synthetic fabrics were treated by electron beam surface coating with two formulations based on polydimethylsiloxane (PDMS) and polystyrene (PS) or poly(methyl methacrylate) (PMMA) oligomers. The water resistance properties were investigated in terms of the percentage of water repellency and absorption. Also, the surface coated fabrics were examined by scanning electron microscopy/microscope (SEM) connected to an energy dispersive X-ray (EDX) unit to determine the percentage atomic contents of elements. The results showed that the adhesion of the polysiloxane formulation to the surface depends largely on the kind of acrylate oligomer and textile fabric as indicated by the EDX analysis for silicon. In this regard, PDMS/PS formulation is more compatible with polyester and nylon-6 fabrics than PDMS/PMMA one. However, it was found that PDMS/PMMA formulation is more compatible with cotton/polyester blend than PDMS/PS. The SEM micrographs give further supports to the EDX analysis. On the basis of the perce...

  20. Water resistance and surface morphology of synthetic fabrics covered by polysiloxane/acrylate followed by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    El-Naggar, A.M. E-mail: ab_nagga@yahoo.com; Zohdy, M.H.; Mohammed, S.S.; Alam, E.A

    2003-04-01

    Different synthetic fabrics were treated by electron beam surface coating with two formulations based on polydimethylsiloxane (PDMS) and polystyrene (PS) or poly(methyl methacrylate) (PMMA) oligomers. The water resistance properties were investigated in terms of the percentage of water repellency and absorption. Also, the surface coated fabrics were examined by scanning electron microscopy/microscope (SEM) connected to an energy dispersive X-ray (EDX) unit to determine the percentage atomic contents of elements. The results showed that the adhesion of the polysiloxane formulation to the surface depends largely on the kind of acrylate oligomer and textile fabric as indicated by the EDX analysis for silicon. In this regard, PDMS/PS formulation is more compatible with polyester and nylon-6 fabrics than PDMS/PMMA one. However, it was found that PDMS/PMMA formulation is more compatible with cotton/polyester blend than PDMS/PS. The SEM micrographs give further supports to the EDX analysis. On the basis of the percentage of water repellency and absorption, polyester fabric displayed the highest water resistance properties among the studied textile fabrics regardless of the used polysiloxane formulation.

  1. O2 evolution and cyclic electron flow around photosystem I in long-term ground batch culture of Euglena gracilis

    Science.gov (United States)

    An, Yanjun; Wang, Suqin; Hao, Zongjie; Zhou, Yiyong; Liu, Yongding

    2014-12-01

    Based on the purpose of better exploring the function of green producers in the closed aquatic biological life support system, the condition of dynamic O2 evolution and performance of cyclic electron flow around photosystem I (CEF-PSI) in long-term ground batch culture of Euglena gracilis were studied, the relationship between linear electron flow (LEF) and CEF-PSI was revealed, the function of CEF-PSI was investigated. Excellent consistency in O2 evolution pattern was observed in cultures grown in both closed and open containers, O2 evolution was strictly suppressed in phase 1, but the rate of it increased significantly in phase 2. CEF-PSI was proposed to be active during the whole course of cultivation, even in the declining phase 3, it still operated at the extent of 47-55%. It is suggested that the relationship between LEF and CEF-PSI is not only competition but also reciprocity. CEF-PSI was proposed to contribute to the considerable growth in phase 1; it was also suggested to play an important protective role against photosystem II (PSII) photoinhibition at the greatly enhanced level (approximately 80-95%) on the 2nd day. Our results in this research suggest that E. gracilis had very particular photosynthetic characteristics, the strict O2 evolution suppression in the initial culture phase might be a special light acclimation behavior, and CEF-PSI could be an important mechanism involved in this kind of adaptation to the changeable light environment.

  2. 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...

  3. Collisional relaxation of apocarotenals: identifying the S* state with vibrationally excited molecules in the ground electronic state S(0)*.

    Science.gov (United States)

    Ehlers, Florian; Scholz, Mirko; Schimpfhauser, Jens; Bienert, Jürgen; Oum, Kawon; Lenzer, Thomas

    2015-04-28

    In recent work, we demonstrated that the S* signal of β-carotene observed in transient pump-supercontinuum probe absorption experiments agrees well with the independently measured steady-state difference absorption spectrum of vibrationally hot ground state molecules S0* in solution, recorded at elevated temperatures (Oum et al., Phys. Chem. Chem. Phys., 2010, 12, 8832). Here, we extend our support for this "vibrationally hot ground state model" of S* by experiments for the three terminally aldehyde-substituted carotenes β-apo-12'-carotenal, β-apo-4'-carotenal and 3',4'-didehydro-β,ψ-caroten-16'-al ("torularhodinaldehyde") which were investigated by ultrafast pump-supercontinuum probe spectroscopy in the range 350-770 nm. The apocarotenals feature an increasing conjugation length, resulting in a systematically shorter S1 lifetime of 192, 4.9 and 1.2 ps, respectively, in the solvent n-hexane. Consequently, for torularhodinaldehyde a large population of highly vibrationally excited molecules in the ground electronic state is quickly generated by internal conversion (IC) from S1 already within the first picosecond of relaxation. As a result, a clear S* signal is visible which exhibits the same spectral characteristics as in the aforementioned study of β-carotene: a pronounced S0 → S2 red-edge absorption and a "finger-type" structure in the S0 → S2 bleach region. The cooling process is described in a simplified way by assuming an initially formed vibrationally very hot species S0** which subsequently decays with a time constant of 3.4 ps to form a still hot S0* species which relaxes with a time constant of 10.5 ps to form S0 molecules at 298 K. β-Apo-4'-carotenal behaves in a quite similar way. Here, a single vibrationally hot S0* species is sufficient in the kinetic modeling procedure. S0* relaxes with a time constant of 12.1 ps to form cold S0. Finally, no S0* features are visible for β-apo-12'-carotenal. In that case, the S1 → S0 IC process is expected

  4. ROVIBRATIONAL LINE LISTS FOR NINE ISOTOPOLOGUES OF THE CO MOLECULE IN THE X {sup 1}Σ{sup +} GROUND ELECTRONIC STATE

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gang; Gordon, Iouli E.; Rothman, Laurence S. [Harvard-Smithsonian Center for Astrophysics, Atomic and Molecular Physics Division, Cambridge, MA 02138 (United States); Tan, Yan; Hu, Shui-Ming [Hefei National Laboratory for Sciences at Microscale, University of Science and Technology of China, 230026 Hefei (China); Kassi, Samir; Campargue, Alain [Laboratoire Interdisciplinaire de Physique, CNRS UMR 5588, Université Joseph Fourier de Grenoble, B.P. 87, F-38402 Saint-Martin-d' Hères Cedex (France); Medvedev, Emile S., E-mail: igordon@cfa.harvard.edu [The Institute of Problems of Chemical Physics, Russian Academy of Science, Prospect Akademika Semenova 1, 142432 Chernogolovka (Russian Federation)

    2015-01-01

    Extensive rovibrational line lists were computed for nine isotopologues of the CO molecule, namely, {sup 12}C{sup 16}O, {sup 12}C{sup 17}O, {sup 12}C{sup 18}O, {sup 13}C{sup 16}O, {sup 13}C{sup 17}O, {sup 13}C{sup 18}O, {sup 14}C{sup 16}O, {sup 14}C{sup 17}O, and {sup 14}C{sup 18}O in the ground electronic state with v ≤ 41, Δv ≤ 11, and J ≤ 150. The line intensity and position calculations were carried out using a newly determined piece-wise dipole moment function (DMF) in conjunction with the wavefunctions calculated from an experimentally determined potential energy function from Coxon and Hajigeorgiou. A direct-fit method that simultaneously fits all the reliable experimental rovibrational matrix elements has been used to construct the dipole moment function near equilibrium internuclear distance. In order to extend the amount and quality of input experimental parameters, new Cavity Ring Down Spectroscopy experiments were carried out to enable measurements of the lines in the 4-0 band with low uncertainty as well as the first measurements of lines in the 6-0 band. A new high-level ab initio DMF, derived from a finite field approach has been calculated to cover internuclear distances far from equilibrium. Accurate partition sums have been derived for temperatures up to 9000 K. In addition to air- and self-induced broadening and shift parameters, those induced by CO{sub 2} and H{sub 2} are now provided for planetary applications. A complete set of broadening and shift parameters was calculated based on sophisticated extrapolation of high-quality measured data. The line lists, which follow HITRAN formalism, are provided as supplementary material.

  5. GREECE -- Ground-to-Rocket Electrodynamics-Electrons Correlative Experiment: High resolution rocket and ground-based investigations of small-scale auroral structure and dynamics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Methodology The methodology is based on making comparisons between downward electron flux, DC electric fields, electromagnetic waves, and auroral morphology. The...

  6. 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。

  7. 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。

  8. Uniform Treatment of Solute-Solvent Dispersion in the Ground and Excited Electronic States of the Solute Based on a Solvation Model with State-Specific Polarizability.

    Science.gov (United States)

    Marenich, Aleksandr V; Cramer, Christopher J; Truhlar, Donald G

    2013-08-13

    We present a new kind of treatment of the solute-solvent dispersion contribution to the free energy of solvation using a solvation model with state-specific polarizability (SMSSP). To evaluate the solute-solvent dispersion contribution, the SMSSP model utilizes only two descriptors, namely, the spherically averaged dipole polarizability of the solute molecule (either in its ground or excited electronic state) and the refractive index of the solvent. The model was parametrized over 643 ground-state solvation free energy data for 231 solutes in 14 nonpolar, non-hydrogen-bonding solvents. We show that the SMSSP model is applicable to solutes in both the ground and the excited electronic state. For example, in comparison to available experimental data, the model yields qualitatively accurate predictions of the solvatochromic shifts for a number of systems where solute-solvent dispersion is the dominant contributor to the shift.

  9. Three methods to retrieve slant total electron content measurements from ground-based GPS receivers and performance assessment

    Science.gov (United States)

    Zhang, Baocheng

    2016-07-01

    The high sampling rate along with the global coverage of ground-based receivers makes Global Positioning System (GPS) data particularly ideal for sensing the Earth's ionosphere. Retrieval of slant total electron content measurements (TECMs) constitutes a key first step toward extracting various ionospheric parameters from GPS data. Within the ionospheric community, the interpretation of TECM is widely recognized as the slant total electron content along the satellite receiver line of sight, biased by satellite and receiver differential code biases (DCBs). The Carrier-to-Code Leveling (CCL) has long been used as a geometry-free method for retrieving TECM, mainly because of its simplicity and effectiveness. In fact, however, the CCL has proven inaccurate as it may give rise to TECM very susceptible to so-called leveling errors. With the goal of attaining more accurate TECM retrieval, we report in this contribution two other methods than the CCL, namely, the Precise Point Positioning (PPP) and the Array-aided PPP (A-PPP). The PPP further exploits the International GPS Service (IGS) orbit and clock products and turns out to be a geometry-based method. The A-PPP is designed to retrieve TECM from an array of colocated receivers, taking advantage of the broadcast orbit and clock products. Moreover, A-PPP also takes into account the fact that the ionospheric effects measured from one satellite to all colocated receivers ought to be the same, thus leading to the estimability of interreceiver DCB. We perform a comparative study of the formal precision and the empirical accuracy of the TECM that are retrieved, respectively, by three methods from the same set of GPS data. Results of such a study can be used to assess the actual performance of the three methods. In addition, we check the temporal stability in A-PPP-derived interreceiver DCB estimates over time periods ranging from 1 to 3 days.

  10. An exploration of electronic structure and nuclear dynamics in tropolone. I. The X~ 1A1 ground state

    Science.gov (United States)

    Burns, Lori A.; Murdock, Daniel; Vaccaro, Patrick H.

    2006-05-01

    The ground electronic state (X˜A11) of tropolone has been examined theoretically by exploiting extensive sets of basis functions [e.g., 6-311++G(d,p) and aug-cc-pVDZ] in conjunction with the high levels of electron correlation made possible by density functional (DFT/B3LYP), Møller-Plesset perturbation (MP2), and coupled-cluster [CCSD and CCSD(T)] methods. Unconstrained MP2 and CCSD optimization procedures performed with the reference 6-311++G(d,p) basis predict a slightly nonplanar equilibrium structure characterized by a small barrier to skeletal inversion (⩽10cm-1 magnitude). Complementary harmonic frequency analyses have shown this nonplanarity to be a computational artifact arising from adversely tuned carbon d-orbital exponents embodied in the standard definitions of several Pople-type basis sets. Correlation-consistent bases such as Dunning's aug-cc-pVDZ are less susceptible to these effects and were employed to confirm that the X˜A11 hypersurface supports a rigorously planar global minimum. The fully optimized geometries and vibrational force fields obtained by applying potent coupled-cluster schemes to the relaxed-equilibrium (Cs) and transition-state (C2v) conformers of tropolone afford a trenchant glimpse of the key features that mediate intramolecular hydron exchange in this model system. By incorporating perturbative triples corrections at the substantial CCSD(T) level of theory, an interoxygen distance of rO ⋯O=2.528Å was determined for the minimum-energy configuration, with the accompanying proton-transfer reaction being hindered by a barrier of 2557.0cm-1 height. The potential energy landscape in tropolone, as well as the nature of the attendant hydron migration process, is discussed within the framework of the encompassing G4 molecular symmetry group.

  11. The Raman effect and its application to electronic spectroscopies in metal-centered species : Techniques and investigations in ground and excited states

    NARCIS (Netherlands)

    Browne, W.R.; J. McGarvey, J.

    2007-01-01

    In the decades since its discovery and somewhat limited early applications, Raman scattering has become the basis for the development of a variety of methods for probing molecular structure both in ground and electronically excited states. In this review, following a brief look at the underlying pri

  12. Criteria for selecting optimum blower drives. Integrated power electronics is gaining ground in the market; Kriterien zur Auswahl des optimalen Ventilatorantriebs. Die integrierte Leistungselektronik gewinnt Marktanteile

    Energy Technology Data Exchange (ETDEWEB)

    Albig, J. [Ziehl-Abegg AG, Kuenzelsau (Germany). Fachbereich Produktmanagement

    2008-05-15

    In the field of speed controllers, systems with power electronics are gaining ground. Thes compact, matched units simplify the installation of refrigeration systems and enable reliable and efficient operation. Design concepts vary between the various producers, and blower design and technology may be quite different. (orig.)

  13. The Raman effect and its application to electronic spectroscopies in metal-centered species : Techniques and investigations in ground and excited states

    NARCIS (Netherlands)

    Browne, W.R.; J. McGarvey, J.

    In the decades since its discovery and somewhat limited early applications, Raman scattering has become the basis for the development of a variety of methods for probing molecular structure both in ground and electronically excited states. In this review, following a brief look at the underlying

  14. 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...

  15. Communication: The ground electronic state of Si{sub 2}C: Rovibrational level structure, quantum monodromy, and astrophysical implications

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, Neil J.; Kokkin, Damian L.; McCarthy, Michael C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, Massachusetts 02138 (United States); Changala, P. Bryan [JILA, National Institute of Standards and Technology and Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Baraban, Joshua H. [Department of Chemistry, University of Colorado, Boulder, Colorado 80309 (United States); Stanton, John F. [Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2015-06-21

    We report the gas-phase optical detection of Si{sub 2}C near 390 nm and the first experimental investigation of the rovibrational structure of its {sup 1}A{sub 1} ground electronic state using mass-resolved and fluorescence spectroscopy and variational calculations performed on a high-level ab initio potential. From this joint study, it is possible to assign all observed K{sub a} = 1 vibrational levels up to 3800 cm{sup −1} with confidence, as well as a number of levels in the K{sub a} = 0, 2,  and 3 manifolds. Dixon-dip plots for the bending coordinate (ν{sub 2}) allow an experimental determination of a barrier to linearity of 783(48) cm{sup −1} (2σ), in good agreement with theory (802(9) cm{sup −1}). The calculated (K{sub a}, ν{sub 2}) eigenvalue lattice shows an archetypal example of quantum monodromy (absence of a globally valid set of quantum numbers) that is reflected by the experimentally observed rovibrational levels. The present study provides a solid foundation for infrared and optical surveys of Si{sub 2}C in astronomical objects, particularly in the photosphere of N- and J-type carbon stars where the isovalent SiC{sub 2} molecule is known to be abundant.

  16. Ab initio potential energy surface and excited vibrational states for the electronic ground state of Li2H

    Institute of Scientific and Technical Information of China (English)

    鄢国森; 先晖; 谢代前

    1997-01-01

    A 285-pomt multi-reference configuration-interaction involving single and double excitations ( MRS DCI) potential energy surface for the electronic ground state of L12H is determined by using 6-311G (2df,2pd)basis set.A Simons-Parr-Finlan polynomial expansion is used to fit the discrete surface with a x2 of 4.64×106 The equn librium geometry occurs at Rc=0.172 nm and,LiHL1=94.10°.The dissociation energy for reaction I2H(2A)→L12(1∑g)+H(2S) is 243.910 kJ/mol,and that for reaction L12H(2A’)→HL1(1∑) + L1(2S) is 106.445 kl/mol The inversion barrier height is 50.388 kj/mol.The vibrational energy levels are calculated using the discrete variable representation (DVR) method.

  17. Magneto-tunnelling spectroscopy for spatial mapping of orbital wavefunctions of the ground and excited electronic states in self-assembled quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Levin, A.; Vdovin, E.E.; Patane, A.; Eaves, L.; Main, P.C.; Dubrovskii, Yu.V.; Henini, M. [Nnottingham Univ. (United Kingdom). School of Physics and Astronomy; Khanin, Yu.N. [Rossijskaya Akademiya Nauk, Chernogolovka (Russian Federation). Inst. of Microelectronics Technology; Hill, G. [Sheffield Univ. (United Kingdom). Dept. of Electronic and Electrical Engineering

    2001-04-01

    We present an experimental study of electron wavefunctions in InAs/GaAs self-assembled quantum dots (QDs). Magneto-tunnelling spectroscopy is employed as a non-invasive probe to produce two-dimensional images of the probability density of an electron confined in a quantum dot. The images reveal clearly the elliptical symmetry of the ground state and the characteristic lobes of the higher energy states of the dots. We use the technique to compare the symmetry properties of the electron wavefunctions in QDs grown on (100)- and (311)B-oriented GaAs substrates. (orig.)

  18. Probing charge transfer in benzodifuran-C60 dumbbell-type electron donor-acceptor conjugates: ground- and excited-state assays.

    Science.gov (United States)

    Li, Hui; Schubert, Christina; Dral, Pavlo O; Costa, Rubén D; La Rosa, Andrea; Thüring, Jürg; Liu, Shi-Xia; Yi, Chenyi; Filippone, Salvatore; Martín, Nazario; Decurtins, Silvio; Clark, Timothy; Guldi, Dirk M

    2013-09-16

    Rigid electron donor-acceptor conjugates (1-3) that combine π-extended benzodifurans as electron donors and C60 molecules as electron acceptors with different linkers have been synthesized and investigated with respect to intramolecular charge-transfer events. Electrochemistry, fluorescence, and transient absorption measurements revealed tunable and structure-dependent charge-transfer processes in the ground and excited states. Our experimental findings are underpinned by density-functional theory calculations. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A combined IR/IR and IR/UV spectroscopy study on the proton transfer coordinate of isolated 3-hydroxychromone in the electronic ground and excited state.

    Science.gov (United States)

    Stamm, A; Weiler, M; Brächer, A; Schwing, K; Gerhards, M

    2014-10-21

    In this paper the excited state proton transfer (ESPT) of isolated 3-hydroxychromone (3-HC), the prototype of the flavonols, is investigated for the first time by combined IR/UV spectroscopy in molecular beam experiments. The IR/UV investigations are performed both for the electronically excited and electronic ground state indicating a spectral overlap of transitions of the 3-HC monomer and clusters with water in the electronic ground state, whereas in the excited state only the IR frequencies of the proton-transferred monomer structure are observed. Due to the loss of isomer and species selectivity with respect to the UV excitations IR/IR techniques are applied in order to figure out the assignment of the vibrational transitions in the S0 state. In this context the quadruple resonance IR/UV/IR/UV technique (originally developed to distinguish different isomers in the electronically excited state) could be applied to identify the OH stretching vibration of the monomer in the electronic ground state. In agreement with calculations the OH stretching frequency differs significantly from the corresponding values of substituted hydroxychromones.

  20. 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

  1. High orbital angular momentum quantum numbers in the electronic ground states of Fe$_2^+$ and Co$_2^+$ as determined by x-ray absorption and x-ray magnetic circular dichroism spectroscopy

    CERN Document Server

    Zamudio-Bayer, V; Langenberg, A; Lawicki, A; Terasaki, A; Issendorff, B v; Lau, J T

    2015-01-01

    The $^6\\Delta$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap. Three candidates, $^6\\Phi$, $^6\\Gamma$, and $^8\\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable ground-state orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ elements cannot be assumed to be connected by a one-electron process.

  2. 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...

  3. Adapting algebraic diagrammatic construction schemes for the polarization propagator to problems with multi-reference electronic ground states exploiting the spin-flip ansatz

    Science.gov (United States)

    Lefrancois, Daniel; Wormit, Michael; Dreuw, Andreas

    2015-09-01

    For the investigation of molecular systems with electronic ground states exhibiting multi-reference character, a spin-flip (SF) version of the algebraic diagrammatic construction (ADC) scheme for the polarization propagator up to third order perturbation theory (SF-ADC(3)) is derived via the intermediate state representation and implemented into our existing ADC computer program adcman. The accuracy of these new SF-ADC(n) approaches is tested on typical situations, in which the ground state acquires multi-reference character, like bond breaking of H2 and HF, the torsional motion of ethylene, and the excited states of rectangular and square-planar cyclobutadiene. Overall, the results of SF-ADC(n) reveal an accurate description of these systems in comparison with standard multi-reference methods. Thus, the spin-flip versions of ADC are easy-to-use methods for the calculation of "few-reference" systems, which possess a stable single-reference triplet ground state.

  4. 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

  5. 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.

  6. An Experimentally Based Description of the Ground-state Wavefunction for Two Weakly Coupled Electrons by Photoelectron Spectroscopy and Magnetic Susceptibility Measurements

    OpenAIRE

    Rankin, Richard; Seddon, Elaine A.; Teuben, Jan H.; Jonkman-Beuker, Anneke H.; Boer, Dirk K.G. de

    1981-01-01

    It is possible to extract values for the transfer energy, t, and the Coulomb interaction, U, in hydrogen-like systems from a combination of photoelectron and magnetic data, as both the form of the photoelectron spectrum and the exchange splitting are determined by these quantities. This procedure is used to evaluate the ground-state wavefunction for the two weakly coupled Ti 3d electrons in (C10H8)(C5H5)2Ti2Cl2.

  7. Lateral ordering of PTCDA on the clean and the oxygen pre-covered Cu(100) surface investigated by scanning tunneling microscopy and low energy electron diffraction.

    Science.gov (United States)

    Gärtner, Stefan; Fiedler, Benjamin; Bauer, Oliver; Marele, Antonela; Sokolowski, Moritz M

    2014-01-01

    We have investigated the adsorption of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) on the clean and on the oxygen pre-covered Cu(100) surface [referred to as (√2 × 2√2)R45° - 2O/Cu(100)] by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). Our results confirm the (4√2 × 5√2)R45° superstructure of PTCDA/Cu(100) reported by A. Schmidt et al. [J. Phys. Chem. 1995, 99,11770-11779]. However, contrary to Schmidt et al., we have no indication for a dissociation of the PTCDA upon adsorption, and we propose a detailed structure model with two intact PTCDA molecules within the unit cell. Domains of high lateral order are obtained, if the deposition is performed at 400 K. For deposition at room temperature, a significant density of nucleation defects is found pointing to a strong interaction of PTCDA with Cu(100). Quite differently, after preadsorption of oxygen and formation of the (√2 × 2√2)R45° - 2O/Cu(100) superstructure on Cu(100), PTCDA forms an incommensurate monolayer with a structure that corresponds well to that of PTCDA bulk lattice planes.

  8. Lateral ordering of PTCDA on the clean and the oxygen pre-covered Cu(100 surface investigated by scanning tunneling microscopy and low energy electron diffraction

    Directory of Open Access Journals (Sweden)

    Stefan Gärtner

    2014-09-01

    Full Text Available We have investigated the adsorption of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA on the clean and on the oxygen pre-covered Cu(100 surface [referred to as (√2 × 2√2R45° – 2O/Cu(100] by scanning tunneling microscopy (STM and low energy electron diffraction (LEED. Our results confirm the (4√2 × 5√2R45° superstructure of PTCDA/Cu(100 reported by A. Schmidt et al. [J. Phys. Chem. 1995, 99,11770–11779]. However, contrary to Schmidt et al., we have no indication for a dissociation of the PTCDA upon adsorption, and we propose a detailed structure model with two intact PTCDA molecules within the unit cell. Domains of high lateral order are obtained, if the deposition is performed at 400 K. For deposition at room temperature, a significant density of nucleation defects is found pointing to a strong interaction of PTCDA with Cu(100. Quite differently, after preadsorption of oxygen and formation of the (√2 × 2√2R45° – 2O/Cu(100 superstructure on Cu(100, PTCDA forms an incommensurate monolayer with a structure that corresponds well to that of PTCDA bulk lattice planes.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. Infrared, Raman, and ultraviolet absorption spectra and theoretical calculations and structure of 2,3,5,6-tetrafluoropyridine in its ground and excited electronic states

    Energy Technology Data Exchange (ETDEWEB)

    Sheu, Hong-Li; Boopalachandran, Praveenkumar [Department of Chemistry, Texas A& M University, College Station, TX 77843-3255 (United States); Kim, Sunghwan [National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Department of Health and Human Services, 8600 Rockville Pike, Bethesda, MD 20894 (United States); Laane, Jaan, E-mail: laane@chem.tamu.edu [Department of Chemistry, Texas A& M University, College Station, TX 77843-3255 (United States)

    2015-07-29

    Highlights: • The structures of 2,3,5,6-tetrafluoropyridine for its S{sub 0} and S{sub 1}(π, π{sup ∗}) states have been calculated. • TFPy is rigidly planar in its ground electronic state, but is quasi-planar and floppy in S{sub 1}. • The barrier to planarity is 30 cm{sup −1} in the excited state. • The observed vibrational frequencies for both states agree well with the computations. • A ring-bending potential energy function for the S{sub 1}(π, π{sup ∗}) state was proposed. - Abstract: Infrared and Raman spectra of 2,3,5,6-tetrafluoropyridine (TFPy) were recorded and vibrational frequencies were assigned for its S{sub 0} electronic ground states. Ab initio and density functional theory (DFT) calculations were used to complement the experimental work. The lowest electronic excited state of this molecule was investigated with ultraviolet absorption spectroscopy and theoretical CASSCF calculations. The band origin was found to be at 35,704.6 cm{sup −1} in the ultraviolet absorption spectrum. A slightly puckered structure with a barrier to planarity of 30 cm{sup −1} was predicted by CASSCF calculations for the S{sub 1}(π, π{sup ∗}) state. Lower frequencies for the out-of-plane ring bending vibrations for the electronic excited state result from the weaker π bonding within the pyridine ring.

  14. 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.

  15. Effect of Electron Correlations and Breit Interactions on Ground-State Fine-Structures along the Nitrogen-Like Isoelectronic Sequence

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Lu; LU Wen-Lai; GAO Xiang; LI Jia-Ming

    2009-01-01

    @@ The accurate atomic data of nitrogen and nitrogen-like ions have an importance role in fusion plasma studies and astrophysics studies. The precise calculation of fine-structures is required to obtain such atomic data. Along the whole nitrogen isoelectronic sequence, the contributions of the electron correlations, the Breit interactions and the quantum electrodynamics corrections on the ground-state fine-structures are elucidated. When Z is low, the electron correlations are important, and the Breit interactions, which cannot be neglected cause interesting anomalous fine-structure splittings. When Z is high, the electron correlations are less important, and the Breit interactions are important in addition to spin-orbit interactions for precise calculations.

  16. Time-dependent renormalized natural orbital theory applied to the two-electron spin-singlet case: ground state, linear response, and autoionization

    CERN Document Server

    Brics, M

    2013-01-01

    Favorably scaling numerical time-dependent many-electron techniques such as time-dependent density functional theory (TDDFT) with adiabatic exchange-correlation potentials typically fail in capturing highly correlated electron dynamics. We propose a method based on natural orbitals, i.e., the eigenfunctions of the one-body reduced density matrix, that is almost as inexpensive numerically as adiabatic TDDFT, but which is capable of describing correlated phenomena such as doubly excited states, autoionization, Fano profiles in the photoelectron spectra, and strong-field ionization in general. Equations of motion (EOM) for natural orbitals and their occupation numbers have been derived earlier. We show that by using renormalized natural orbitals (RNO) both can be combined into one equation governed by a hermitian effective Hamiltonian. We specialize on the two-electron spin-singlet system, known as being a "worst case" testing ground for TDDFT, and employ the widely used, numerically exactly solvable, one-dimens...

  17. A quantitative description of the ground-state wave function of Cu(A) by X-ray absorption spectroscopy: comparison to plastocyanin and relevance to electron transfer.

    Science.gov (United States)

    DeBeer George, S; Metz, M; Szilagyi, R K; Wang, H; Cramer, S P; Lu, Y; Tolman, W B; Hedman, B; Hodgson, K O; Solomon, E I

    2001-06-20

    To evaluate the importance of the electronic structure of Cu(A) to its electron-transfer (ET) function, a quantitative description of the ground-state wave function of the mixed-valence (MV) binuclear Cu(A) center engineered into Pseudomonas aeruginosa azurin has been developed, using a combination of S K-edge and Cu L-edge X-ray absorption spectroscopies (XAS). Parallel descriptions have been developed for a binuclear thiolate-bridged MV reference model complex ([(L(i)(PrdacoS)Cu)(2)](+)) and a homovalent (II,II) analogue ([L(i)(Pr2tacnS)Cu)(2)](2+), where L(i)(PrdacoS) and L(i)(Pr2tacnS) are macrocyclic ligands with attached thiolates that bridge the Cu ions. Previous studies have qualitatively defined the ground-state wave function of Cu(A) in terms of ligand field effects on the orbital orientation and the presence of a metal--metal bond. The studies presented here provide further evidence for a direct Cu--Cu interaction and, importantly, experimentally quantify the covalency of the ground-state wave function. The experimental results are further supported by DFT calculations. The nature of the ground-state wave function of Cu(A) is compared to that of the well-defined blue copper site in plastocyanin, and the importance of this wave function to the lower reorganization energy and ET function of Cu(A) is discussed. This wave function incorporates anisotropic covalency into the intra- and intermolecular ET pathways in cytochrome c oxidase. Thus, the high covalency of the Cys--Cu bond allows a path through this ligand to become competitive with a shorter His path in the intramolecular ET from Cu(A) to heme a and is particularly important for activating the intermolecular ET path from heme c to Cu(A).

  18. Ground-state and magnetocaloric properties of a coupled spin-electron double-tetrahedral chain (exact study at the half filling)

    Science.gov (United States)

    Gálisová, Lucia; Jakubczyk, Dorota

    2017-01-01

    Ground-state and magnetocaloric properties of a double-tetrahedral chain, in which nodal lattice sites occupied by the localized Ising spins regularly alternate with triangular clusters half filled with mobile electrons, are exactly investigated by using the transfer-matrix method in combination with the construction of the Nth tensor power of the discrete Fourier transformation. It is shown that the ground state of the model is formed by two non-chiral phases with the zero residual entropy and two chiral phases with the finite residual entropy S = NkB ln 2. Depending on the character of the exchange interaction between the localized Ising spins and mobile electrons, one or three magnetization plateaus can be observed in the magnetization process. Their heights basically depend on the values of Landé g-factors of the Ising spins and mobile electrons. It is also evidenced that the system exhibits both the conventional and inverse magnetocaloric effect depending on values of the applied magnetic field and temperature.

  19. Organic electronic materials: Recent advances in the dft description of the ground and excited states using tuned range-separated hybrid functionals

    KAUST Repository

    Körzdörfer, Thomas

    2014-11-18

    Density functional theory (DFT) and its time-dependent extension (TD-DFT) are powerful tools enabling the theoretical prediction of the ground- and excited-state properties of organic electronic materials with reasonable accuracy at affordable computational costs. Due to their excellent accuracy-to-numerical-costs ratio, semilocal and global hybrid functionals such as B3LYP have become the workhorse for geometry optimizations and the prediction of vibrational spectra in modern theoretical organic chemistry. Despite the overwhelming success of these out-of-the-box functionals for such applications, the computational treatment of electronic and structural properties that are of particular interest in organic electronic materials sometimes reveals severe and qualitative failures of such functionals. Important examples include the overestimation of conjugation, torsional barriers, and electronic coupling as well as the underestimation of bond-length alternations or excited-state energies in low-band-gap polymers.In this Account, we highlight how these failures can be traced back to the delocalization error inherent to semilocal and global hybrid functionals, which leads to the spurious delocalization of electron densities and an overestimation of conjugation. The delocalization error for systems and functionals of interest can be quantified by allowing for fractional occupation of the highest occupied molecular orbital. It can be minimized by using long-range corrected hybrid functionals and a nonempirical tuning procedure for the range-separation parameter.We then review the benefits and drawbacks of using tuned long-range corrected hybrid functionals for the description of the ground and excited states of π-conjugated systems. In particular, we show that this approach provides for robust and efficient means of characterizing the electronic couplings in organic mixed-valence systems, for the calculation of accurate torsional barriers at the polymer limit, and for the

  20. The potential surface in the ground electronic state of HCP with the isomerization process: the validity of calculating potential surface with DFT methods

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The density functional theory (DFT) provides us an effective way to calculate large cluster systems with moderate computational demands. We calculate potential energy surfaces (PES) with several different approaches of DFT. The PES in the ground electronic state are related to HCP's isomerization process. The calculated PES are compared with the “experimental” PES obtained by fitting from the experimental vibrational spectra and that given by the “accurate” quantum chemistry calculation with more expensive computations. The comparisons show that the potential surfaces calculated with DFT methods can reach the accuracy of less than 0.1 eV.

  1. 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

  2. Fast Energy Transfer and Molecular Dynamics in the Electronic Ground State Of C{sub 2}H{sub 2} and H{sub 2}CO Viewed By Time Resolved FS-CARS

    Energy Technology Data Exchange (ETDEWEB)

    Knopp, G.; Beaud, P.; Radi, P.; Tulej, M.; Gerber, T.

    2004-03-01

    The molecular dynamics in the electronic ground state of C{sub 2}H{sub 2} and of H{sub 2}CO have been interrogated by the femto second CARS method. For a discussion of collision induced rotational and vibrational energy transfer in the electronic ground state of the polyatomic acetylene (C{sub 2H}2) molecule the transient signals were evaluated with the recently developed angular momentum and energy corrected scaling law. (author)

  3. Calculation of electronic coupling matrix elements for ground and excited state electron transfer reactions: Comparison of the generalized Mulliken-Hush and block diagonalization methods

    Science.gov (United States)

    Cave, Robert J.; Newton, Marshall D.

    1997-06-01

    Two independent methods are presented for the nonperturbative calculation of the electronic coupling matrix element (Hab) for electron transfer reactions using ab initio electronic structure theory. The first is based on the generalized Mulliken-Hush (GMH) model, a multistate generalization of the Mulliken Hush formalism for the electronic coupling. The second is based on the block diagonalization (BD) approach of Cederbaum, Domcke, and co-workers. Detailed quantitative comparisons of the two methods are carried out based on results for (a) several states of the system Zn2OH2+ and (b) the low-lying states of the benzene-Cl atom complex and its contact ion pair. Generally good agreement between the two methods is obtained over a range of geometries. Either method can be applied at an arbitrary nuclear geometry and, as a result, may be used to test the validity of the Condon approximation. Examples of nonmonotonic behavior of the electronic coupling as a function of nuclear coordinates are observed for Zn2OH2+. Both methods also yield a natural definition of the effective distance (rDA) between donor (D) and acceptor (A) sites, in contrast to earlier approaches which required independent estimates of rDA, generally based on molecular structure data.

  4. Electronics Technician 3

    Science.gov (United States)

    1957-01-01

    grade of of a strong, pliable wood strip and securing sandpaper (No. 00) may be used. Sandpapering the canvas with rivets, as shown in figure is also...and use properly personnel. insulated tools; cover the deck with an approved All electronics personnel must become thor- insulating material; and make...not struction, the worker must be insulated from be broken except when absolutely necessary and accidental grounding by the use of approved authorized

  5. Theoretical study on potential energy curves and spectroscopy properties of ground and low-lying excited electronic states of BrCl~+

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The calculations on the potential energy curves and spectroscopic constants of the ground and low-lying excited states of BrCl+,one of the important molecular ions in environment science,have been performed by using the multireference configuration interaction method at high level of theory in quantum chemistry.Through analyses of the effects of the spin-orbit coupling interaction on the elec-tronic structures and spectroscopic properties,the multiconfiguration characteristic of the X2Π ground state and low-lying excited states was established.The spin-orbit coupling splitting energy of the X2 Π ground state was calculated to be 1814 cm-1,close to the experimental value 2070 cm-1.The spin-orbit coupling splitting energy of the 2Π(Ⅱ) exited state was predicted to be 766 cm-1.The transition dipole moments and Frank-Condon factors of the 3/2(Ⅲ)-X3/2 and 1/2(Ⅲ)-1/2(I) transitions were estimated,and the radiative lifetimes of the two transitions were briefly discussed.

  6. Adapting algebraic diagrammatic construction schemes for the polarization propagator to problems with multi-reference electronic ground states exploiting the spin-flip ansatz

    Energy Technology Data Exchange (ETDEWEB)

    Lefrancois, Daniel; Wormit, Michael; Dreuw, Andreas, E-mail: dreuw@uni-heidelberg.de [Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 368, 69120 Heidelberg (Germany)

    2015-09-28

    For the investigation of molecular systems with electronic ground states exhibiting multi-reference character, a spin-flip (SF) version of the algebraic diagrammatic construction (ADC) scheme for the polarization propagator up to third order perturbation theory (SF-ADC(3)) is derived via the intermediate state representation and implemented into our existing ADC computer program adcman. The accuracy of these new SF-ADC(n) approaches is tested on typical situations, in which the ground state acquires multi-reference character, like bond breaking of H{sub 2} and HF, the torsional motion of ethylene, and the excited states of rectangular and square-planar cyclobutadiene. Overall, the results of SF-ADC(n) reveal an accurate description of these systems in comparison with standard multi-reference methods. Thus, the spin-flip versions of ADC are easy-to-use methods for the calculation of “few-reference” systems, which possess a stable single-reference triplet ground state.

  7. Theoretical study on potential energy curves and spectroscopy properties of ground and low-lying excited electronic states of BrCl+

    Institute of Scientific and Technical Information of China (English)

    WANG MingWei; WANG BingWu; CHEN ZhiDa

    2008-01-01

    The calculations on the potential energy curves and spectroscopic constants of the ground and low-lying excited states of BrCl+, one of the important molecular ions in environment science, have been performed by using the multireference configuration interaction method at high level of theory in quantum chemistry. Through analyses of the effects of the spin-orbit coupling interaction on the electronic structures and spectroscopic properties, the multiconfiguration characteristic of the X2∏ ground state and low-lying excited states was established. The spin-orbit coupling splitting energy of the X2∏ ground state was calculated to be 1814 cm-1, close to the experimental value 2070 cm-1. The spin-orbit coupling splitting energy of the 2∏(Ⅱ) exited state was predicted to be 766 cm-1. The transition dipole moments and Frank-Condon factors of the 3/2(Ⅲ)-X3/2 and 1/2(Ⅲ)-1/2(Ⅰ) transitions were estimated, and the radiative lifetimes of the two transitions were briefly discussed.

  8. 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.

  9. 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.

  10. Ground and excited electronic state analysis of PrF²⁺ and PmF²⁺.

    Science.gov (United States)

    Schoendorff, George; Chi, Benjamin; Ajieren, Hans; Wilson, Angela K

    2015-03-05

    The ground state and excited state manifolds are computed for PrF(2+) and PmF(2+) at the CASSCF (n,8) level of theory where the active space spans the Ln 4f orbitals as well as the F 2pz orbital. Dynamical correlation is included using second-order multireference quasidegenerate perturbation theory (MCQDPT2). The spin-orbit multiplets for each of the excited states are resolved, and spin-orbit coupling constants are computed using the Breit-Pauli spin-orbit operator. Equilibrium geometries for each of the ground and excited states are computed, and the nature of the Ln-F bond is examined. Potential energy curves for the lowest four triplet states and lowest two quintet states are computed for PrF(2+), which split into 14 levels upon application of the spin-orbit Hamiltonian. Likewise, the lowest six quintet states are computed for PmF(2+) as well as the lowest triplet state and the lowest two septet states. These nine states split into 43 terms upon application of the spin-orbit Hamiltonian.

  11. 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

  12. 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

  13. Electron-microscopic analysis of ground elder (Aegopodium podagraria L.) lectin: evidence for a new type of supra-molecular protein structure.

    Science.gov (United States)

    Leurentop, L; Verbelen, J P; Peumans, W J

    1987-09-01

    The lectin of ground elder (Aegopodium podagraria L.) was investigated electron-microscopically after negative staining with uranyl salts. Affinity-purified preparations of this glycoprotein were highly heteromorphous as they contained small particles approximately 4.6 nm in diameter and very large particles of different shapes. Among the latter, circular and helicoidal structures were the most regular in appearance. The circles were 9.3 nm in diameter, whereas the helices were 9 nm or 20 nm in diameter and up to 60 nm in length. After photographic enhancement, pictures of the molecules indicated that both the larger structures and the small particles could be obtained in pure forms by gel filtration of the lectin on Sepharose 4B. Since the former were the only constituents of the excluded fraction (Mr>5000000), whereas they were totally absent in the fraction eluting with an apparent molecular weight of about 500000, these supra-molecular structures revealed by the electron microscope cannot be artefacts generated during preparation of the lectin for electron-microscopic observation.

  14. Half-metallicity and spin-contamination of the electronic ground state of graphene nanoribbons and related systems: an impossible compromise?

    Science.gov (United States)

    Huzak, M; Deleuze, M S; Hajgató, B

    2011-09-14

    An analysis using the formalism of crystalline orbitals for extended systems with periodicity in one dimension demonstrates that any antiferromagnetic and half-metallic spin-polarization of the edge states in n-acenes, and more generally in zigzag graphene nanoislands and nanoribbons of finite width, would imply a spin contamination S(2) that increases proportionally to system size, in sharp and clear contradiction with the implications of Lieb's theorem for compensated bipartite lattices and the expected value for a singlet (S = 0) electronic ground state. Verifications on naphthalene, larger n-acenes (n = 3-10) and rectangular nanographene islands of increasing size, as well as a comparison using unrestricted Hartree-Fock theory along with basis sets of improving quality against various many-body treatments demonstrate altogether that antiferromagnetism and half-metallicity in extended graphene nanoribbons will be quenched by an exact treatment of electron correlation, at the confines of non-relativistic many-body quantum mechanics. Indeed, for singlet states, symmetry-breakings in spin-densities are necessarily the outcome of a too approximate treatment of static and dynamic electron correlation in single-determinantal approaches, such as unrestricted Hartree-Fock or Density Functional Theory. In this context, such as the size-extensive spin-contamination to which it relates, half-metallicity is thus nothing else than a methodological artefact.

  15. Infrared, Raman, and Ultraviolet Absorption Spectra and Theoretical Calculations and Structure of 2,6-Difluoropyridine in its Ground and Excited Electronic States

    Science.gov (United States)

    Sheu, Hong-Li; Kim, Sunghwan; Laane, Jaan

    2014-01-01

    The infrared and Raman spectra of 2,6-difluoropyridine (26DFPy) along with ab initio and DFT computations have been used to assign the vibrations of the molecule in its S0 electronic ground state and to calculate its structure. The ultraviolet absorption spectrum showed the electronic transition to the S1(π,π*) state to be at 37,820.2 cm−1. With the aid of ab initio computations the vibrational frequencies for this excited state were also determined. TD-B3LYP and CASSCF computations for the excited states were carried out to calculate the structures for the S1(π,π*) and S2(n,π*) excited states. The CASSCF results predict that the S1(π,π*) state is planar and the S2(n,π*) state has a barrier to planarity of 256 cm−1. The TD-B3LYP computations predict a barrier of 124 cm−1 for the S1(π,π*) states, but the experimental results support the planar structure. Hypothetical models for the ring-puckering potential energy function were calculated for both electronic excited states to show the predicted quantum states. The changes in the vibrational frequencies in the two excited states reflect the weaker π bonding within the pyridine ring. PMID:24070189

  16. Ejection of quasi-free electron pairs from the helium atom ground state by single photon absorption

    CERN Document Server

    Schöffler, M S; Waitz, M; Trinter, F; Jahnke, T; Lenz, U; Jones, M; Belkacem, A; Landers, A; Pindzola, M S; Cocke, C L; Colgan, J; Kheifets, A; Bray, I; Schmidt-Böcking, H; Dörner, R; Weber, Th

    2012-01-01

    We investigate single photon double ionization (PDI) of helium at photon energies of 440 and 800 eV. We observe doubly charged ions with close to zero momentum corresponding to electrons emitted back-to-back with equal energy. These slow ions are the unique fingerprint of an elusive quasi-free PDI mechanism predicted by Amusia et al. nearly four decades years ago [J. Phys. B 8, 1248, (1975)] . It results from the non-dipole part of the electromagnetic interaction. Our experimental data are in excellent agreement with calculations performed using the convergent close coupling and time dependent close coupling methods.

  17. Ground Testing and Flight Demonstration of Charge Management of Insulated Test Masses Using UV LED Electron Photoemission

    CERN Document Server

    Saraf, Shailendhar; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; AlRashed, Abdullah; Nassban, Badr Al; Suwaidan, Badr Al; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; DeBra, Daniel; Byer, Robert

    2016-01-01

    The UV LED mission demonstrates the precise control of the potential of electrically isolated test masses that is essential for the operation of space accelerometers and drag free sensors. Accelerometers and drag free sensors were and remain at the core of geodesy, aeronomy, and precision navigation missions as well as gravitational science experiments and gravitational wave observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV LED mission and prior ground testing demonstrates that AlGaN UV LEDs operating at 255 nm are superior to Mercury vapor lamps because of their smaller size, lower draw, higher dynamic range, and higher control authority. We show flight data from a small satellite mission on a Saudi Satellite that demonstrates AC charge control (UV LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its h...

  18. Direct observation of electronic and nuclear ground state splitting in external magnetic field by inelastic neutron scattering on oxidized ferrocene and ferrocene containing polymers

    Directory of Open Access Journals (Sweden)

    Appel Markus

    2015-01-01

    Full Text Available The quantum mechanical splitting of states by interaction of a magnetic moment with an external magnetic field is well known, e.g., as Zeeman effect in optical transitions, and is also often seen in magnetic neutron scattering. We report excitations observed in inelastic neutron spectroscopy on the redox-responsive polymer poly(vinylferrocene. They are interpreted as splitting of the electronic ground state in the organometallic ferrocene units attached to the polymer chain where a magnetic moment is created by oxidation. In a second experiment using high resolution neutron backscattering spectroscopy we observe the hyperfine splitting, i.e., interaction of nuclear magnetic moments with external magnetic fields leading to sub-μeV excitations observable in incoherent neutron spin-flip scattering on hydrogen and vanadium nuclei.

  19. Explicit large nuclear charge limit of electronic ground states for Li, Be, B, C, N, O, F, Ne and basic aspects of the periodic table

    CERN Document Server

    Friesecke, Gero

    2008-01-01

    This paper is concerned with the Schr\\"odinger equation for atoms and ions with N=1 to 10 electrons. In the asymptotic limit of large nuclear charge $Z$, we determine explicitly the low-lying energy levels and eigenstates. The asymptotic energies and wavefunctions are in good quantitative agreement with experimental data for positive ions, and in excellent qualitative agreement even for neutral atoms ($Z=N$). In particular, the predicted ground state spin and angular momentum quantum numbers ($^1S$ for He, Be, Ne, $^2S$ for H and Li, $^4S$ for N, $^2P$ for B and F, and $^3P$ for C and O) agree with experiment in every case. The asymptotic Schr\\"odinger ground states agree, up to small corrections, with the semi-empirical hydrogen orbital configurations developed by Bohr, Hund and Slater to explain the periodic table. In rare cases where our results deviate from this picture, such as the ordering of the lowest ${}^1D^o$ and ${}^5S^o$ states of Carbon, experiment confirms our, not Hund's, predictions.

  20. Ground testing and flight demonstration of charge management of insulated test masses using UV-LED electron photoemission

    Science.gov (United States)

    Saraf, Shailendhar; Buchman, Sasha; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; Suwaidan, Badr Al; AlRashed, Abdullah; Al-Nassban, Badr; Alaqeel, Faisal; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; Alfauwaz, Abdulrahman; Al-Majed, Mohammed; DeBra, Daniel; Byer, Robert

    2016-12-01

    The UV-LED mission demonstrates the precise control of the potential of electrically isolated test masses. Test mass charge control is essential for the operation of space accelerometers and drag-free sensors which are at the core of geodesy, aeronomy and precision navigation missions as well as gravitational wave experiments and observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV-LED mission and prior ground testing demonstrates that AlGaN UVLEDs operating at 255 nm are superior to Hg lamps because of their smaller size, lower power draw, higher dynamic range, and higher control authority. We show laboratory data demonstrating the effectiveness and survivability of the UV-LED devices and performance of the charge management system. We also show flight data from a small satellite experiment that was one of the payloads on KACST’s SaudiSat-4 mission that demonstrates ‘AC charge control’ (UV-LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its housing. The result of the mission brings the UV-LED device Technology Readiness Level (TRL) to TRL-9 and the charge management system to TRL-7. We demonstrate the ability to control the test mass potential on an 89 mm diameter spherical test mass over a 20 mm gap in a drag-free system configuration, with potential measured using an ultra-high impedance contact probe. Finally, the key electrical and optical characteristics of the UV-LEDs showed less than 7.5% change in performance after 12 months in orbit.

  1. Spin polarized low energy electron microscopy of quantum well resonances in Fe films on the Cu-covered W(110) surface.

    Science.gov (United States)

    Wu, Qiang; Altman, M S

    2013-07-01

    Spin polarized low energy electron microscopy has been used to investigate the quantum size effect (QSE) in electron reflectivity from Fe films grown on a pseudomorphic Cu layer on a W(110) surface. Intensity oscillations caused by the QSE as functions of Fe film thickness and incident electron energy identify quantum well resonance conditions in the film. Evaluation of these intensity oscillations using the phase accumulation model provides information on the unoccupied spin polarized band structure in the Fe film above the vacuum level. We also find evidence that the presence of the non-magnetic Cu layer shifts spin polarized quantum well resonances in the Fe layer uniformly downward in energy by 1.1eV compared to Fe/W(110) films without an interface Cu layer, suggesting that the Cu layer gives a small degree of control over the quantum well resonances.

  2. 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...

  3. 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...

  4. Ground-state phase diagram, fermionic entanglement and kinetically-induced frustration in a hybrid ladder with localized spins and mobile electrons

    Science.gov (United States)

    Carvalho, R. C. P.; Pereira, M. S. S.; de Oliveira, I. N.; Strečka, J.; Lyra, M. L.

    2017-09-01

    We introduce an exactly solvable hybrid spin-ladder model containing localized nodal Ising spins and interstitial mobile electrons, which are allowed to perform a quantum-mechanical hopping between the ladder’s legs. The quantum-mechanical hopping process induces an antiferromagnetic coupling between the ladder’s legs that competes with a direct exchange coupling of the nodal spins. The model is exactly mapped onto the Ising spin ladder with temperature-dependent two- and four-spin interactions, which is subsequently solved using the transfer-matrix technique. We report the ground-state phase diagram and compute the fermionic concurrence to characterize the quantum entanglement between the pair of interstitial mobile electrons. We further provide a detailed analysis of the local spin ordering including the pair and four-spin correlation functions around an elementary plaquette, as well as, the local ordering diagrams. It is shown that a complex sequence of distinct local orderings and frustrated correlations takes place when the model parameters drive the investigated system close to a zero-temperature triple coexistence point.

  5. 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

  6. 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。

  7. 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...

  8. 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...

  9. 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.

  10. 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

  11. Properties of ground state and anomalous quantum fluctuations in one-dimensional polaron-soliton ystems——the effects of electron-two-phonon interaction and non-adiabatic quantum correlations

    Institute of Scientific and Technical Information of China (English)

    Luo Zhi-Hua; Cao Xi-Jin; Yu Chao-Fan

    2011-01-01

    Based on the Holstein model Hamiltonian of one-dimensional molecular crystals, by making use of the expansion approach of the correlated squeezed-coherent states of phonon instead of the two-phonon coherent state expansion scheme, the properties of the ground state and the anomalous quantum fluctuations are investigated in a strongly coupled electron-phonon system with special consideration of the electron-two-phonon interaction. The effective renormalization ((~α)i) of the displacement of the squeezed phonons with the effect of the squeezed-coherent states of phonon and both the electron-displaced phonon and the polaron-squeezed phonon correlations have been combined to obtain the anomalous quantum fluctuations for the corrections of the coherent state. Due to these non-adiabatic correlations, the effective displacement parameter (~α)i is larger than the ordinary parameter αi(0). In comparison with the electron-one-phonon interaction (g) corrected as (~α)ig, we have found the electron-two-phonon interaction (g1) corrected as (~α)2ig1 is enhanced significantly. For this reason, the ground state energy (EO(2)) contributed by the electron-two-phonon interaction is more negative than the single-phonon case (EO(1)) and the soliton solution is more stable. At the same time, the effects of the electron-two-phonon interaction greatly increase the polaron energy and the quantum fluctuations. Furthermore,in a deeper level, we have considered the effect of the polaron-squeezed phonon correlation (f-correlation). Since this correlation parameter f > 1, this effect will strengthen the electron-one and two-phonon interactions by f(~α)ig and f2( ~α)2i1, respectively. The final results show that the ground state energy and the polaron energy will appear more negative further and the quantum fluctuations will gain further improvement.

  12. Analysis of methods for calculating the transition frequencies of the torsional vibration of acrolein isomers in the ground ( S 0) electronic state

    Science.gov (United States)

    Koroleva, L. A.; Tyulin, V. I.; Matveev, V. K.; Pentin, Yu. A.

    2013-05-01

    B3LYP, MP2, CCSD(T), and MP4/MP2 in the 6-311G( d, p), 6-311++G( d, p), cc-pVTZ, aug-cc-pVTZ bases used to calculate the transition frequencies of torsional vibration of trans- and cis-isomers of acrolein in the ground electronic state ( S 0) are analyzed. It is found that for trans-isomers, all methods of calculation except for B3LYP in the cc-pVTZ basis yield good agreement between the calculated and experimental values. It is noted that for the cis-isomer of acrolein, no method of calculation confirms the experimental value of the frequency of torsional vibration (138 cm-1). It is shown that the calculated and experimental values for obertones at 273.0 cm-1 and other transitions of torsional vibration are different for this isomer in particular. However, it is established that in some calculation methods (B3LYP, MP2), the frequency of the torsional vibration of the cis-isomer coincides with another experimental value of this frequency (166.5 cm-1). It is concluded that in analyzing the vibrational structure of the UV spectrum, the calculated and experimental values of its obertone (331.3 cm-1) coincide, along with its frequency. It is also noted that the frequency of torsional vibration for the cis-isomer (166.5 cm-1) can also be found in other experimental works if we change the allocation of torsional transition 18{1/1}.

  13. Electron microscope studies

    Energy Technology Data Exchange (ETDEWEB)

    Crewe, A.V.; Kapp, O.H.

    1992-07-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

  14. 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.

  15. 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? ...

  16. 7 CFR 1755.402 - Ground resistance measurements.

    Science.gov (United States)

    2010-01-01

    ... ground resistance of electronic equipment such as span line repeaters, carrier terminal equipment... Protection Grounding Fundamentals,” for a comprehensive discussion of ground resistance measurements. (d... electronic equipment, the ground resistance shall not exceed 25 ohms. Where the measured ground...

  17. 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.

  18. 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.

  19. 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...

  20. 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...

  1. 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...

  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. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  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. Keeping electronic records secure.

    Science.gov (United States)

    Easton, David

    2013-10-01

    Are electronic engineering maintenance records relating to the hospital estate or a medical device as important as electronic patient records? Computer maintenance management systems (CMMS) are increasingly being used to manage all-round maintenance activities. However, the accuracy of the data held on them, and a level of security that prevents tampering with records, or other unauthorised changes to them to 'cover' poor practice, are both essential, so that, should an individual be injured or killed on hospital grounds, and a law suit follow, the estates team can be confident that it has accurate data to prove it has fulfilled its duty of care. Here David Easton MSc CEng FIHEEM MIET, director of Zener Engineering Services, and chair of IHEEM's Medical Devices Advisory Group, discusses the issues around maintenance databases, and the security and integrity of maintenance data.

  8. 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...

  9. 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.

  10. 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....

  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. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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.

  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.

    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.

  11. Fundamentals of electronic systems design

    CERN Document Server

    Lienig, Jens

    2017-01-01

    This textbook covers the design of electronic systems from the ground up, from drawing and CAD essentials to recycling requirements. Chapter by chapter, it deals with the challenges any modern system designer faces: the design process and its fundamentals, such as technical drawings and CAD, electronic system levels, assembly and packaging issues and appliance protection classes, reliability analysis, thermal management and cooling, electromagnetic compatibility (EMC), all the way to recycling requirements and environmental-friendly design principles. Enables readers to face various challenges of designing electronic systems, including coverage from various engineering disciplines; Written to be accessible to readers of varying backgrounds; Uses illustrations extensively to reinforce fundamental concepts; Organized to follow essential design process, although chapters are self-contained and can be read in any order.

  12. Wave packet and statistical quantum calculations for the He + NeH{sup +} → HeH{sup +} + Ne reaction on the ground electronic state

    Energy Technology Data Exchange (ETDEWEB)

    Koner, Debasish; Panda, Aditya N., E-mail: adi07@iitg.ernet.in [Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039 (India); Barrios, Lizandra; González-Lezana, Tomás, E-mail: t.gonzalez.lezana@csic.es [Instituto de Física Fundamental, C.S.I.C., Serrano 123, Madrid 28006 (Spain)

    2014-09-21

    A real wave packet based time-dependent method and a statistical quantum method have been used to study the He + NeH{sup +} (v, j) reaction with the reactant in various ro-vibrational states, on a recently calculated ab initio ground state potential energy surface. Both the wave packet and statistical quantum calculations were carried out within the centrifugal sudden approximation as well as using the exact Hamiltonian. Quantum reaction probabilities exhibit dense oscillatory pattern for smaller total angular momentum values, which is a signature of resonances in a complex forming mechanism for the title reaction. Significant differences, found between exact and approximate quantum reaction cross sections, highlight the importance of inclusion of Coriolis coupling in the calculations. Statistical results are in fairly good agreement with the exact quantum results, for ground ro-vibrational states of the reactant. Vibrational excitation greatly enhances the reaction cross sections, whereas rotational excitation has relatively small effect on the reaction. The nature of the reaction cross section curves is dependent on the initial vibrational state of the reactant and is typical of a late barrier type potential energy profile.

  13. Data assimilation of ground GPG total electron content into a physics-based ionosheric model by use of the Kalman filter

    Science.gov (United States)

    Hajj, G. A.; Wilson, B. D.; Wang, C.; Pi, X.; Rosen, I. G.

    2004-01-01

    A three-dimensional (3-D) Global Assimilative Ionospheric Model (GAIM) is currently being developed by a joint University of Southern California and Jet Propulsion Laboratory (JPL) team. To estimate the electron density on a global grid, GAIM uses a first-principles ionospheric physics model and the Kalman filter as one of its possible estimation techniques.

  14. 电子信息系统工程中防雷接地探讨%Electronic Information Systems Engineering Lightning Protection and Grounding Discussion

    Institute of Scientific and Technical Information of China (English)

    徐宝春; 徐亚东

    2014-01-01

    随着信息与控制技术的飞速发展,电子信息系统日益增加,这些电子信息系统中的电子器件的集成和超大规模集成化,普遍存在着绝缘强度低、过电压耐受能力差等弱点。雷电对这些电子设备潜伏着严重的不安全性,一旦发生雷击事件,导致信息系统无法实时对外提供服务,将造成不可估量的直接与间接的经济损失和影响。%With the rapid development of information and control technology, electronic information systems increasing integration and ultra-large-scale integration, the prevalence of low dielectric strength of these electronic information system of electronic devices, over-voltage tolerance of poor weakness. Lightning serious of these electronic devices lurking insecurity, once lightning incident occurred not real-time information systems to provide services, it will cause immeasurable direct and indirect economic loss and impact.

  15. Micropower electronics

    CERN Document Server

    Keonjian, Edward

    1964-01-01

    Micropower Electronics deals with the operation of modern electronic equipment at micropower levels and the problems associated with micropower electronics. Topics covered include the relations between minimum required power density and frequency response for semiconductor triode amplifiers; physical realization of digital logic circuits; micropower microelectronic subsystems; and metal-oxide-semiconductor field-effect devices for micropower logic circuitry. This book is comprised of 10 chapters and begins with an analysis of fundamental relationships and basic requirements pertinent to the ph

  16. Electronics for LHC Experiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document gathers the abstracts of most presentations made at this workshop on electronics for the large hadron collider (LHC) experiments. The presentations were arranged into 6 sessions: 1) electronics for tracker, 2) trigger electronics, 3) detector control systems, 4) data acquisition, 5) electronics for calorimeters and electronics for muons, and 6) links, power systems, grounding and shielding, testing and quality assurance.

  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

    2017-06-09

    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.

  18. 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.

  19. 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

  20. 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...

  1. 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.

  2. '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...

  3. 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 ...

  4. 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 ...

  5. 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…

  6. 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...

  7. 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...

  8. 离化态原子基态电子结构特征与轨道竞争规律∗%Characteristics of ground state electronic structures of ionized atoms and rules of their orbital comp etitions

    Institute of Scientific and Technical Information of China (English)

    金锐; 高翔; 曾德灵; 顾春; 岳现房; 李家明

    2016-01-01

    Ionized atoms widely exist in plasmas, and studies of properties of ionized atoms are the foundations of frontier science researches such as astrophysics and controlled nuclear fusions. For example, the information about the ground configurations of atoms is required for accurately calculating the physical quantities such as energy levels and dynamical processes. The configurations for different ionized atoms can be obtained with the photo-electron energy spectrum exper-iment, however it is very time-consuming to obtain so many data of all ions. Therefore the more economical theoretical study will be of great importance. As is well known, the configurations of neutral atoms can be determined according to Mendeleev order while those of highly ionized atoms are hydrogen-like due to the strong Coulombic potential of their nuclei. Then with the variations of ionization degree and atomic number along the periodic table, there would appear the interesting competitions between electronic orbitals. Although some theoretical results exist for ions 3 6 Z 6 118, 3 6 N e 6 105 (where Z is the atomic number and N e is the electron number), there are many errors in the results for highly ionized atoms. Therefore, the ground configurations of ionized atoms and their orbital competitions still deserve to be systematically studied. Based on the independent electron approximation, we calculate the energy levels of all possible competition con-figurations of all the neutral and ionized atoms in the extended periodic tables (2 6 Z 6 119) by Dirac-Slater method. Then the ground configurations are determined by calculating the chosen lowest total energy. The advantages of Dirac-Slater method are as follows. 1) It has been shown that the Dirac-Slater calculation is accurate enough for studying the ground properties of atoms, such as the 1st threshold, and that higher accuracy will be obtained for highly ionized atoms, because the electron correlation becomes less important. 2

  9. 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.

  10. 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...

  11. 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....

  12. 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.

  13. 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.

  14. 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.

  15. 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)

  16. 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.

  17. Solution uniquity of an inverse VLF problem: A case-study of the polar, ground-based, VLF radio signal disturbances caused by the ultra-energetic relativistic electron precipitations and of their southern boundaries

    Science.gov (United States)

    Remenets, G. F.; Astafiev, A. M.

    2016-09-01

    Here we present the results of a case study of the rare, abnormal, qualitatively specific behavior of Aldra (northern Norway) and GBR (UK) VLF transmitter signals (10-16 kHz) received at Kola Peninsula. The abnormal amplitude and the phase disturbances of signals were used as a proxy for ultra-energetic relativistic (solar?) electron precipitation (URE, ∼100 MeV) into the middle polar atmosphere. The disturbances have been observed under quiet or moderately disturbed geomagnetic activity. Based on bearing results, it was established that the abnormal variations of the electric conductivity of ionized middle atmosphere (of a sporadic Ds layer under the regular ionosphere D layer) were characterized by the following: (i) the time function of height h(t) of an effective spherical waveguide between the Earth surface and the sporadic Ds layer shows a minimum value equal to ∼30 km and (ii) the reflection coefficient R(t) of radio wave with a grazing angle of incidence from a virtual boundary with height h(t) has a minimum value equal to ∼0.4. The southern boundaries of the ultra-energetic relativistic electron precipitations have been found as well. They turned out to be not southerly than 61 degree of magnetic latitude and similar to the ones obtained in our previous study of the events for other dates under the similar geophysical conditions although we do not know anything definite about the rigidity and density of the electron fluxes. A used calculation method of analysis is based on a necessary condition that a number n of input data should be greater than a number m of output parameter-functions. We have stated by numerical testing that a decrease of n from 6 to 4 generates a lack of uniqueness of an inverse VLF problem solution for m = 2. It is important for future VLF ground-based monitoring of the URE precipitation events.

  18. 27 CFR 73.10 - What does subpart B cover?

    Science.gov (United States)

    2010-04-01

    ...? 73.10 Section 73.10 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURES AND PRACTICES ELECTRONIC SIGNATURES; ELECTRONIC SUBMISSION OF FORMS Electronic Signatures § 73.10 What does subpart B cover? This subpart provides...

  19. 27 CFR 73.30 - What does subpart C cover?

    Science.gov (United States)

    2010-04-01

    ...? 73.30 Section 73.30 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURES AND PRACTICES ELECTRONIC SIGNATURES; ELECTRONIC SUBMISSION OF FORMS Electronic Filing of Documents with TTB § 73.30 What does subpart C cover? This...

  20. Ground Levels and Ionization Energies for the Neutral Atoms

    Science.gov (United States)

    SRD 111 Ground Levels and Ionization Energies for the Neutral Atoms (Web, free access)   Data for ground state electron configurations and ionization energies for the neutral atoms (Z = 1-104) including references.

  1. 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...

  2. Introduction to Electronic Marketing.

    Science.gov (United States)

    Dilbeck, Lettie

    These materials for a five-unit course were developed to introduce secondary and postsecondary students to the use of electronic equipment in marketing. The units cover the following topics: electronic marketing as a valid marketing approach; telemarketing; radio electronic media marketing; television electronic media marketing; and cable TV…

  3. 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...

  4. Electronic and vibrational spectra of protonated benzaldehyde-water clusters, [BZ-(H2O)n≤5]H+: evidence for ground-state proton transfer to solvent for n ≥ 3.

    Science.gov (United States)

    Dopfer, Otto; Patzer, Alexander; Chakraborty, Shamik; Alata, Ivan; Omidyan, Reza; Broquier, Michel; Dedonder, Claude; Jouvet, Christophe

    2014-03-28

    Vibrational and electronic photodissociation spectra of mass-selected protonated benzaldehyde-(water)n clusters, [BZ-(H2O)n]H(+) with n ≤ 5, are analyzed by quantum chemical calculations to determine the protonation site in the ground electronic state (S0) and ππ(*) excited state (S1) as a function of microhydration. IR spectra of [BZ-(H2O)n]H(+) with n ≤ 2 are consistent with BZH(+)-(H2O)n type structures, in which the excess proton is localized on benzaldehyde. IR spectra of clusters with n ≥ 3 are assigned to structures, in which the excess proton is located on the (H2O)n solvent moiety, BZ-(H2O)nH(+). Quantum chemical calculations at the B3LYP, MP2, and ri-CC2 levels support the conclusion of proton transfer from BZH(+) to the solvent moiety in the S0 state for hydration sizes larger than the critical value nc = 3. The vibronic spectrum of the S1 ← S0 transition (ππ(*)) of the n = 1 cluster is consistent with a cis-BZH(+)-H2O structure in both electronic states. The large blueshift of the S1 origin by 2106 cm(-1) upon hydration with a single H2O ligand indicates that the proton affinity of BZ is substantially increased upon S1 excitation, thus strongly destabilizing the hydrogen bond to the solvent. The adiabatic S1 excitation energy and vibronic structure calculated at the ri-CC2/aug-cc-pVDZ level agrees well with the measured spectrum, supporting the notion of a cis-BZH(+)-H2O geometry. The doubly hydrated species, cis-BZH(+)-(H2O)2, does not absorb in the spectral range of 23 000-27 400 cm(-1), because of the additional large blueshift of the ππ(*) transition upon attachment of the second H2O molecule. Calculations predict roughly linear and large incremental blueshifts for the ππ(*) transition in [BZ-(H2O)n]H(+) as a function of n. In the size range n ≥ 3, the calculations predict a proton transfer from the (H2O)nH(+) solvent back to the BZ solute upon electronic ππ(*) excitation.

  5. Electronic and vibrational spectra of protonated benzaldehyde-water clusters, [BZ-(H2O)n≤5]H+: Evidence for ground-state proton transfer to solvent for n ≥ 3

    Science.gov (United States)

    Dopfer, Otto; Patzer, Alexander; Chakraborty, Shamik; Alata, Ivan; Omidyan, Reza; Broquier, Michel; Dedonder, Claude; Jouvet, Christophe

    2014-03-01

    Vibrational and electronic photodissociation spectra of mass-selected protonated benzaldehyde-(water)n clusters, [BZ-(H2O)n]H+ with n ≤ 5, are analyzed by quantum chemical calculations to determine the protonation site in the ground electronic state (S0) and ππ* excited state (S1) as a function of microhydration. IR spectra of [BZ-(H2O)n]H+ with n ≤ 2 are consistent with BZH+-(H2O)n type structures, in which the excess proton is localized on benzaldehyde. IR spectra of clusters with n ≥ 3 are assigned to structures, in which the excess proton is located on the (H2O)n solvent moiety, BZ-(H2O)nH+. Quantum chemical calculations at the B3LYP, MP2, and ri-CC2 levels support the conclusion of proton transfer from BZH+ to the solvent moiety in the S0 state for hydration sizes larger than the critical value nc = 3. The vibronic spectrum of the S1 ← S0 transition (ππ*) of the n = 1 cluster is consistent with a cis-BZH+-H2O structure in both electronic states. The large blueshift of the S1 origin by 2106 cm-1 upon hydration with a single H2O ligand indicates that the proton affinity of BZ is substantially increased upon S1 excitation, thus strongly destabilizing the hydrogen bond to the solvent. The adiabatic S1 excitation energy and vibronic structure calculated at the ri-CC2/aug-cc-pVDZ level agrees well with the measured spectrum, supporting the notion of a cis-BZH+-H2O geometry. The doubly hydrated species, cis-BZH+-(H2O)2, does not absorb in the spectral range of 23 000-27 400 cm-1, because of the additional large blueshift of the ππ* transition upon attachment of the second H2O molecule. Calculations predict roughly linear and large incremental blueshifts for the ππ* transition in [BZ-(H2O)n]H+ as a function of n. In the size range n ≥ 3, the calculations predict a proton transfer from the (H2O)nH+ solvent back to the BZ solute upon electronic ππ* excitation.

  6. 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.

  7. 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.

  8. 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.

  9. Electrical Ground Support Equipment Fabrication, Specification for

    Science.gov (United States)

    Denson, Erik C.

    2014-01-01

    This document specifies parts, materials, and processes used in the fabrication, maintenance, repair, and procurement of electrical and electronic control and monitoring equipment associated with ground support equipment (GSE) at the Kennedy Space Center (KSC).

  10. Digital electronics

    CERN Document Server

    Morris, John

    2013-01-01

    An essential companion to John C Morris's 'Analogue Electronics', this clear and accessible text is designed for electronics students, teachers and enthusiasts who already have a basic understanding of electronics, and who wish to develop their knowledge of digital techniques and applications. Employing a discovery-based approach, the author covers fundamental theory before going on to develop an appreciation of logic networks, integrated circuit applications and analogue-digital conversion. A section on digital fault finding and useful ic data sheets completes th

  11. Experimental cross-sections energy dependence and an ab initio electronic structure survey of the ground singlet potential surface for reactive Li(+) + n-C(3)H(7)Cl collisions at low energies.

    Science.gov (United States)

    Lucas, José María; de Andrés, Jaime; Albertí, Margarita; Bofill, Josep Maria; Bassi, Davide; Aguilar, Antonio

    2010-11-07

    Reactive collisions between n-C(3)H(7)Cl molecules and lithium ions both in their ground electronic state have been studied in the 0.05-7.00 eV center of mass energy range using an octopole radio frequency guided-ion beam apparatus developed in our laboratory and recently modified. At low collision energies, dehydrohalogenation reactions leading to Li(C(3)H(6))(+) and Li(HCl)(+) are the main reaction channels, while on increasing energies C(3)H(7)(+) and C(2)H(3)(+) formation become dominant. Cross section energy dependences in arbitrary units for all these reactions have been measured. Also, ab initio electronic structure calculations at the MP2 level have been performed to obtain information about the potential energy surface on which the reactive processes take place. The reactants' entrance channel leads to the formation of a stable [Li-n-C(3)H(7)Cl](+) ion-molecule adduct that, following an intrinsic-reaction-coordinate pathway and surmounting a transition state, isomerizes to [Li-i-C(3)H(7)Cl](+). From this second minimum, dehydrohalogenation reactions for both n-C(3)H(7)Cl and i-C(3)H(7)Cl share a common reaction pathway leading to the same products. All potential barriers explored by reactions always lie below the reactants' energy. The entrance reaction channel [Li-n-C(3)H(7)Cl](+) adduct also leads adiabatically to C(3)H(7)(+) formation which, on increasing collision energy generates C(2)H(3)(+)via a unimolecular decomposition. A qualitative interpretation of the experimental results based on our ab initio calculations is also given.

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. Ultrafast laser control of vibrational dynamics for a two-dimensional model of HONO 2 in the ground electronic state: separation of conformers, control of the bond length, selective preparation of the discrete and the continuum states

    Science.gov (United States)

    Oppel, M.; Paramonov, G. K.

    1998-06-01

    Selective excitation of the vibrational bound and the continuum states, controlled by subpicosecond infrared (IR) laser pulses, is simulated within the Schrödinger wave function formalism for a two-dimensional model of the HONO 2 molecule in the ground electronic state. State-selective excitation of the OH bond is achieved by single optimal laser pulses, with the probability being 97% for the bound states and more than 91% for the resonances. Stable, long-living continuum states are prepared with more than 96% probability by two optimal laser pulses, with the expectation energy of the molecule being well above the dissociation threshold of the ON single bond, and its life-time being at least 100 ps. The length of the ON single bond can be controlled selectively: stretching and contraction by about 45% of its equilibrium length are demonstrated. Laser separation of spatial conformers of HONO 2 in inhomogeneous conditions occurring on an anisotropic surface or created by a direct current (DC) electric field is analysed. The relative yields of target conformers may be very high, ranging from 10 to 10 8, and the absolute yields of up to 40% and more are calculated.

  17. 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 ...

  18. 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.

  19. Measurement of ground motion in various sites

    Energy Technology Data Exchange (ETDEWEB)

    Bialowons, W.; Amirikas, R.; Bertolini, A.; Kruecker, D.

    2007-04-15

    Ground vibrations may affect low emittance beam transport in linear colliders, Free Electron Lasers (FEL) and synchrotron radiation facilities. This paper is an overview of a study program to measure ground vibrations in various sites which can be used for site characterization in relation to accelerator design. Commercial broadband seismometers have been used to measure ground vibrations and the resultant database is available to the scientific community. The methodology employed is to use the same equipment and data analysis tools for ease of comparison. This database of ground vibrations taken in 19 sites around the world is first of its kind. (orig.)

  20. 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...

  1. 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.

  2. 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.

  3. 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

  4. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  5. Electronics engineer's reference book

    CERN Document Server

    Turner, L W

    1976-01-01

    Electronics Engineer's Reference Book, 4th Edition is a reference book for electronic engineers that reviews the knowledge and techniques in electronics engineering and covers topics ranging from basics to materials and components, devices, circuits, measurements, and applications. This edition is comprised of 27 chapters; the first of which presents general information on electronics engineering, including terminology, mathematical equations, mathematical signs and symbols, and Greek alphabet and symbols. Attention then turns to the history of electronics; electromagnetic and nuclear radiatio

  6. 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.

  7. 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.

  8. Integrated Procedures for Flight and Ground Operations Using International Standards

    Science.gov (United States)

    Ingalls, John

    2011-01-01

    Imagine astronauts using the same Interactive Electronic Technical Manuals (IETM's) as the ground personnel who assemble or maintain their flight hardware, and having all of that data interoperable with design, logistics, reliability analysis, and training. Modern international standards and their corresponding COTS tools already used in other industries provide a good foundation for streamlined technical publications in the space industry. These standards cover everything from data exchange to product breakdown structure to business rules flexibility. Full Product Lifecycle Support (PLCS) is supported. The concept is to organize, build once, reuse many ways, and integrate. This should apply to all future and some current launch vehicles, payloads, space stations/habitats, spacecraft, facilities, support equipment, and retrieval ships.

  9. 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.

  10. 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...

  11. Electronic and vibrational spectra of protonated benzaldehyde-water clusters, [BZ-(H{sub 2}O){sub n≤5}]H{sup +}: Evidence for ground-state proton transfer to solvent for n ≥ 3

    Energy Technology Data Exchange (ETDEWEB)

    Dopfer, Otto, E-mail: dopfer@physik.tu-berlin.de; Patzer, Alexander; Chakraborty, Shamik [Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin (Germany); Alata, Ivan; Omidyan, Reza; Broquier, Michel [Institut des Sciences Moleculaires d’Orsay, UMR-CNRS 8214, and Centre Laser de l’Université Paris Sud/LUMAT FR 2764, Batiment 106, l’Université Paris Sud 11, 91405 Orsay Cedex (France); Dedonder, Claude; Jouvet, Christophe [Physique des Interactions Ioniques et Moléculaires, UMR-CNRS 7345 Aix Marseille Université, Avenue Escadrille Normandie-Niémen, 13397 Marseille Cedex 20 (France)

    2014-03-28

    Vibrational and electronic photodissociation spectra of mass-selected protonated benzaldehyde-(water){sub n} clusters, [BZ-(H{sub 2}O){sub n}]H{sup +} with n ≤ 5, are analyzed by quantum chemical calculations to determine the protonation site in the ground electronic state (S{sub 0}) and ππ{sup *} excited state (S{sub 1}) as a function of microhydration. IR spectra of [BZ-(H{sub 2}O){sub n}]H{sup +} with n ≤ 2 are consistent with BZH{sup +}-(H{sub 2}O){sub n} type structures, in which the excess proton is localized on benzaldehyde. IR spectra of clusters with n ≥ 3 are assigned to structures, in which the excess proton is located on the (H{sub 2}O){sub n} solvent moiety, BZ-(H{sub 2}O){sub n}H{sup +}. Quantum chemical calculations at the B3LYP, MP2, and ri-CC2 levels support the conclusion of proton transfer from BZH{sup +} to the solvent moiety in the S{sub 0} state for hydration sizes larger than the critical value n{sub c} = 3. The vibronic spectrum of the S{sub 1} ← S{sub 0} transition (ππ{sup *}) of the n = 1 cluster is consistent with a cis-BZH{sup +}-H{sub 2}O structure in both electronic states. The large blueshift of the S{sub 1} origin by 2106 cm{sup −1} upon hydration with a single H{sub 2}O ligand indicates that the proton affinity of BZ is substantially increased upon S{sub 1} excitation, thus strongly destabilizing the hydrogen bond to the solvent. The adiabatic S{sub 1} excitation energy and vibronic structure calculated at the ri-CC2/aug-cc-pVDZ level agrees well with the measured spectrum, supporting the notion of a cis-BZH{sup +}-H{sub 2}O geometry. The doubly hydrated species, cis-BZH{sup +}-(H{sub 2}O){sub 2}, does not absorb in the spectral range of 23 000–27 400 cm{sup −1}, because of the additional large blueshift of the ππ{sup *} transition upon attachment of the second H{sub 2}O molecule. Calculations predict roughly linear and large incremental blueshifts for the ππ{sup *} transition in [BZ-(H{sub 2}O){sub n

  12. 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.

  13. 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)

  14. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  15. Thermionics basic principles of electronics

    CERN Document Server

    Jenkins, J; Ashhurst, W

    2013-01-01

    Basic Principles of Electronics, Volume I : Thermionics serves as a textbook for students in physics. It focuses on thermionic devices. The book covers topics on electron dynamics, electron emission, and the themionic vacuum diode and triode. Power amplifiers, oscillators, and electronic measuring equipment are studied as well. The text will be of great use to physics and electronics students, and inventors.

  16. 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.

  17. 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...

  18. 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, ...

  19. Cold Regions Logistic Supportability Testing of Electronic, Avionic and Communications Equipment.

    Science.gov (United States)

    2014-09-26

    A18 887 COLD REGIONS LOGISTIC SUPPORTABILITY TESTING OF / AS ELECTRONIC AVIONIC AMD CO..IUI ANY T EST AND EVALUATION COMAND ABERDEEN PROVING GROUND...optimum durability and service life of materiel. (b) To eliminate field maintenance problems encountered in earlier design items. (c) For ease of...heat sensitive). 5.2.2 Analysis. Assess the impact of each supply support anomaly un- covered in relation to the test item. Include comments as to the

  20. 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

  1. Terrestrial radiation effects in ULSI devices and electronic systems

    CERN Document Server

    Ibe, Eishi H

    2014-01-01

    A practical guide on how mathematical approaches can be used to analyze and control radiation effects in semiconductor devices within various environments Covers faults in ULSI devices to failures in electronic systems caused by a wide variety of radiation fields, including electrons, alpha -rays, muons, gamma rays, neutrons and heavy ions. Readers will learn the environmental radiation features at the ground or avionics altitude. Readers will also learn how to make numerical models from physical insight and what kind of mathematical approaches should be implemented to analyze the radiation effects. A wide variety of mitigation techniques against soft-errors are reviewed and discussed. The author shows how to model sophisticated radiation effects in condensed matter in order to quantify and control them. The book provides the reader with the knowledge on a wide variety of radiation fields and their effects on the electronic devices and systems. It explains how electronic systems including servers and rout...

  2. 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.

  3. 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.

  4. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  5. Electronics engineer's reference book

    CERN Document Server

    Mazda, F F

    1989-01-01

    Electronics Engineer's Reference Book, Sixth Edition is a five-part book that begins with a synopsis of mathematical and electrical techniques used in the analysis of electronic systems. Part II covers physical phenomena, such as electricity, light, and radiation, often met with in electronic systems. Part III contains chapters on basic electronic components and materials, the building blocks of any electronic design. Part IV highlights electronic circuit design and instrumentation. The last part shows the application areas of electronics such as radar and computers.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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).

  13. On the ground state of metallic hydrogen

    Science.gov (United States)

    Chakravarty, S.; Ashcroft, N. W.

    1978-01-01

    A proposed liquid ground state of metallic hydrogen at zero temperature is explored and a variational upper bound to the ground state energy is calculated. The possibility that the metallic hydrogen is a liquid around the metastable point (rs = 1.64) cannot be ruled out. This conclusion crucially hinges on the contribution to the energy arising from the third order in the electron-proton interaction which is shown here to be more significant in the liquid phase than in crystals.

  14. 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

  15. 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

  16. 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).

  17. 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

  18. 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

  19. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    energy at the end-user should also be set up. Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources will be high in the near future. Two major technologies will play important roles to solve the future problems. One...... is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...

  20. Spin electronics

    CERN Document Server

    Buhrman, Robert; Daughton, James; Molnár, Stephan; Roukes, Michael

    2004-01-01

    This report is a comparative review of spin electronics ("spintronics") research and development activities in the United States, Japan, and Western Europe conducted by a panel of leading U.S. experts in the field. It covers materials, fabrication and characterization of magnetic nanostructures, magnetism and spin control in magnetic nanostructures, magneto-optical properties of semiconductors, and magnetoelectronics and devices. The panel's conclusions are based on a literature review and a series of site visits to leading spin electronics research centers in Japan and Western Europe. The panel found that Japan is clearly the world leader in new material synthesis and characterization; it is also a leader in magneto-optical properties of semiconductor devices. Europe is strong in theory pertaining to spin electronics, including injection device structures such as tunneling devices, and band structure predictions of materials properties, and in development of magnetic semiconductors and semiconductor heterost...

  1. 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...

  2. 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...

  3. 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.

  4. 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...

  5. 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

  6. 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.

  7. Newnes electronics assembly pocket book

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Produced in association with the Engineering Training Authority with contributions from dozens of people in the electronics industry. The material covers common skills in electrical and electronic engineering and concentrates mainly on wiring and assembly. 'Newnes Electronics Assembly Pocket Book' is for electronics technicians, students and apprentices.

  8. 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...

  9. Electron attachment to Cl 2

    Science.gov (United States)

    McCorkle, D. L.; Christodoulides, A. A.; Christophorou, L. G.

    1984-08-01

    The electron attachment rate constant for Cl 2 as a function of the mean electron energy (0.04-0.78 eV) and temperature (213-323 K) has been measured and is reported; it shows a maximum at near thermal energy and is attributed to dissociative electron attachment via the ground state 2Σ u+ of Cl 2- from the ground state 1Σ g+ of Cl 2.

  10. Electronic properites of electron-doped cuprate superconductors probed by high-field magnetotransport

    Energy Technology Data Exchange (ETDEWEB)

    Helm, Toni

    2013-09-18

    In the present work the normal-state properties of the electron-doped cuprate superconductor Nd{sub 2-x}Ce{sub x}CuO{sub 4} (NCCO) are investigated for a broad doping range, covering almost the whole phase diagram of this material. Magnetotransport measurements in the world's highest non-destructive magnetic fields were used as a spectroscopic tool for probing the electronic structure of single-crystalline NCCO as a function of the carrier concentration x. Quantum and semiclassical oscillations in the magnetoresistance provided new insights into various properties of the Fermi surface and the nature of the ground state in the system. The detailed investigations of the field- and temperature-dependent transport and its dependence on the field orientation have revealed a close correlation between symmetry-breaking ordering instabilities and the superconducting state.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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...

  16. [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.

  17. 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)

  18. Notes on Electronic Lexicography

    CERN Document Server

    Parvanov, Yavor

    2011-01-01

    These notes are a continuation of topics covered by V. Selegej in his article "Electronic Dictionaries and Computational lexicography". How can an electronic dictionary have as its object the description of closely related languages? Obviously, such a question allows multiple answers.

  19. Managing electronic records

    CERN Document Server

    McLeod, Julie

    2005-01-01

    For records management courses, this book covers the theory and practice of managing electronic records as business and information assets. It focuses on the strategies, systems and procedures necessary to ensure that electronic records are appropriately created, captured, organized and retained over time to meet business and legal requirements.

  20. Vegetation cover analysis using a low budget hyperspectral proximal sensing system

    Directory of Open Access Journals (Sweden)

    C. Daquino

    2006-06-01

    Full Text Available This report describes the implementation of a hyperspectral proximal sensing low-budget acquisition system and its application to the detection of terrestrian vegetation cover anomalies in sites of high environmental quality. Anomalies can be due to stress for lack of water and/or pollution phenomena and weed presence in agricultural fields. The hyperspectral cube (90-bands ranging from 450 to 900 nm was acquired from the hill near Segni (RM, approximately 500 m far from the target, by means of electronically tunable filters and 8 bit CCD cameras. Spectral libraries were built using both endmember identification method and extraction of centroids of the clusters obtained from a k-means analysis of the image itself. Two classification methods were applied on the hyperspectral cube: Spectral Angle Mapper (hard and Mixed Tuned Matching Filters (MTMF. Results show the good capability of the system in detecting areas with an arboreal, shrub or leafage cover, distinguishing between zones with different spectral response. Better results were obtained using spectral library originated by the k-means method. The detected anomalies not correlated to seasonal phenomena suggest a ground true analysis to identify their origin.

  1. 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.

  2. 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...

  3. 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.

  4. 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

  5. Electronic components and systems

    CERN Document Server

    Dennis, W H

    2013-01-01

    Electronic Components and Systems focuses on the principles and processes in the field of electronics and the integrated circuit. Covered in the book are basic aspects and physical fundamentals; different types of materials involved in the field; and passive and active electronic components such as capacitors, inductors, diodes, and transistors. Also covered in the book are topics such as the fabrication of semiconductors and integrated circuits; analog circuitry; digital logic technology; and microprocessors. The monograph is recommended for beginning electrical engineers who would like to kn

  6. Electron paramagnetic resonance

    CERN Document Server

    Al'tshuler, S A

    2013-01-01

    Electron Paramagnetic Resonance is a comprehensive text on the field of electron paramagnetic resonance, covering both the theoretical background and the results of experiment. This book is composed of eight chapters that cover theoretical materials and experimental data on ionic crystals, since these are the materials that have been most extensively studied by the methods of paramagnetic resonance. The opening chapters provide an introduction to the basic principles of electron paramagnetic resonance and the methods of its measurement. The next chapters are devoted to the theory of spectra an

  7. 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.

  8. 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.

  9. 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.

  10. 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....

  11. 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....

  12. 31 CFR 370.0 - What does this part cover?

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What does this part cover? 370.0 Section 370.0 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT ELECTRONIC TRANSACTIONS AND FUNDS...

  13. Soldering in electronics assembly

    CERN Document Server

    Judd, Mike

    2013-01-01

    Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Basic principles of electronics thermionics

    CERN Document Server

    Jenkins, J

    2013-01-01

    Basic Principles of Electronics, Volume I: Thermionics covers topics related to thermionic devices. The book starts by providing a physical background about electronics, including structure of matter, ionic, chemical and covalent combination, crystalline structure, conductors and insulators, and thermionic emission. The text then discusses electron dynamics; the characteristics and properties of electrons in solids; electron emission; and thermionic emission in a vacuum diode or triode. The development of the vacuum triode; gas-filled valves; and power amplifiers are also considered. The book

  2. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  3. 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.

  4. Adaptive Magnetorheological Isolator for Ground Support Equipment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The minimization of vibration-induced damage has become a critical issue for rocket launch ground support electronics (GSE). GSE located near a major rocket launch...

  5. Adaptive Magnetorheological Isolator for Ground Support Equipment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The minimization of vibration-induced damage has become a critical issue for rocket launch ground support electronics (GSE). In particular, the effect of high...

  6. Optical Electronics. Electronics Module 9. Instructor's Guide.

    Science.gov (United States)

    Franken, Bill

    This module is the ninth of 10 modules in the competency-based electronics series. Introductory materials include a listing of competencies addressed in the module, a parts/equipment list, and a cross reference table of instructional materials. Five instructional units cover: fiber optic cable; optical coupler; lasers and masers; optical displays;…

  7. 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.

  8. Electronic Portfolios for Faculty Development.

    Science.gov (United States)

    Heath, Marilyn; Cockerham, Steve

    This paper examines the conceptual process of creating an electronic professional portfolio for faculty development. The characteristics of electronic professional portfolios and the benefits of electronic portfolio development are discussed. Additional topics covered include: collection and selection of portfolio contents; reflection on portfolio…

  9. COMPARATIVE ANALYSIS OF GROUNDING RESISTANCE VALUE IN SOIL AND SEPTICTANK

    Directory of Open Access Journals (Sweden)

    Abdul Syakur

    2012-02-01

    Full Text Available The aim of grounding system to protect of electrical equipment and instrumentation system and peopletogether. The lightning stroke near the strucutre of building can damage of equipment and instrumentationsystem. Therefore, it is very important to protect theese electrical and electronic equipment from lightningstrike uses lightning protection system and grounding system.This paper presents kind of grounding system at type of soil and place. The measurement of groundingresistance in soil and septictank have done. Types of soil for grounding resistance measuring aremarshland, clay and rockland.The measurement results of grounding resistance show that value of grounding resistance depend ondeepness of electrode and kind of soil and septictank. Grounding resistance value in septictank is morelower than soil.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 48 CFR 22.1003-5 - Some examples of contracts covered.

    Science.gov (United States)

    2010-10-01

    ..., engines, electrical motors, vehicles, and electronic, office and related business and construction... CFR 4.130 for additional examples): (a) Motor pool operation, parking, taxicab, and ambulance services... detection. (h) Some support services at installations, including grounds maintenance and landscaping....

  17. Ordered Porous Pd Octahedra Covered with Monolayer Ru Atoms.

    Science.gov (United States)

    Ge, Jingjie; He, Dongsheng; Bai, Lei; You, Rui; Lu, Haiyuan; Lin, Yue; Tan, Chaoliang; Kang, Yan-Biao; Xiao, Bin; Wu, Yuen; Deng, Zhaoxiang; Huang, Weixin; Zhang, Hua; Hong, Xun; Li, Yadong

    2015-11-25

    Monolayer Ru atoms covered highly ordered porous Pd octahedra have been synthesized via the underpotential deposition and thermodynamic control. Shape evolution from concave nanocube to octahedron with six hollow cavities was observed. Using aberration-corrected high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy, we provide quantitative evidence to prove that only a monolayer of Ru atoms was deposited on the surface of porous Pd octahedra. The as-prepared monolayer Ru atoms covered Pd nanostructures exhibited excellent catalytic property in terms of semihydrogenation of alkynes.

  18. Electronics pocket book

    CERN Document Server

    Parr, E A

    1981-01-01

    Electronics Pocket Book, Fourth Edition is a nonmathematical presentation of the many varied topics covered by electronics. The book tackles electron physics, electronic components (i.e. resistors, capacitors, and conductors), integrated circuits, and the principles of a.c. and d.c. amplifiers. The text also discusses oscillators, digital circuits, digital computers, and optoelectronics (i.e., sensors, emitters, and devices that utilize light). Communications (such as line and radio communications, transmitters, receivers, and digital techniques); the principles and examples of servosystems; a

  19. 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...

  20. 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

  1. Advanced adhesives in electronics

    CERN Document Server

    Bailey, C

    2011-01-01

    Adhesives are widely used in the manufacture of electronic devices to act as passive and active components. Recently there has been considerable interest in the use of conductive adhesives. This book reviews key types of conductive adhesives, processing methods, properties and the way they can be modelled as well as potential applications.$bAdhesives for electronic applications serve important functional and structural purposes in electronic components and packaging, and have developed significantly over the last few decades. Advanced adhesives in electronics reviews recent developments in adhesive joining technology, processing and properties. The book opens with an introduction to adhesive joining technology for electronics. Part one goes on to cover different types of adhesive used in electronic systems, including thermally conductive adhesives, isotropic and anisotropic conductive adhesives and underfill adhesives for flip-chip applications. Part two focuses on the properties and processing of electronic ...

  2. 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).

  3. 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.

  4. 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.

  5. 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

  6. 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,…

  7. Remediation of radiation belt electrons caused by ground based man-made VLF wave%地基人工 VLF电波对辐射带电子的调制

    Institute of Scientific and Technical Information of China (English)

    王平; 徐岩冰; 于晓霞; 赵小芸; 吴峰; 王焕玉; 马宇蒨; 李新乔; 卢红; 孟祥承; 张吉龙; 王辉; 石峰

    2011-01-01

    辐射带电子的加速与沉降机理是空间物理研究的重要课题.法国DEMETER电磁卫星观测到了美国NPM发射站VLF信号及与之相关的高能电子沉降事例.本研究工作将根据基于回旋共振相互作用的准线性扩散理论,通过对局域投掷角扩散系数的计算,来说明受VLF影响的高能电子的投掷角分布与电子的能量及所处位置的关系.理论计算较好地解释了DEMETER卫星在NPM实验期间所观测到的电子沉降事例.在此基础上进一步讨论了通过人工方式对辐射带高能电子施加影响的效率问题.%The physics mechanisms of radiation belt electrons loss and acceleration are important issues in space physics research. Recently, France Microsatellite DEMETER has discovered the correlation between man- made VLF signals and radiation belt electrons precipitation in the NPM ( the U. S. VLF transmitter located at Lualualei ) experiment. Our research focuses on the explanation of the relation among affected pitch angle distribution, kinetic energy and position of electrons. This is achieved by calculating the local diffusion coeffcient based on the theory of qusi-linear diffusion with resonant interaction. Our result has a good explanation of radiation belt electron precipitation discovered by DEMETER during NPM experiment. Furthermore, we have discussed the effciency of radiation belt remediation in an artificial way.

  8. Electrical, Electronic, and Electromechanical (EEE) Parts Management and Control Requirements for Space Flight Hardware and Critical Ground Support Equipment...aka... The NASA EEE Parts Standard, NASA-STD 8739.10

    Science.gov (United States)

    Majewicz, Peter; Sampson, Michael

    2016-01-01

    Describes development and content of a new NASA Standard for Electrical Electronic and Electromechanical (EEE) parts. This Standard reflects current practices, instead of changing them. Most NASA Centers utilize local documents, but there is minimal consistency across the Agency. A gap analysis clearly shows the differences that exist among the different centers and with respect to the NASA Parts Policy. Once approved, the new standard can be referenced in contracts and agreements with organizations outside of NASA.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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…

  18. 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…

  19. 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.

  20. 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

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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.

  6. 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...

  7. 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...

  8. [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.

  9. 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...

  10. 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.

  11. 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…

  12. 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…

  13. 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

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. Bi covered Si(111) surface revisited

    CERN Document Server

    Miwa, R H; Srivastava, G P

    2003-01-01

    We have performed an ab initio study of the stability, atomic geometry and electronic structure of the Bi-covered (sq root 3 x sq root 3) reconstructed Si(111) surface. We find that the energetically stable structure changes from the milkstool model (for 1 monolayer (ML) coverage) to the T sub 4 model (for 1/3 ML coverage), without going through a stable structure for the honeycomb model (2/3 ML coverage). Our theoretical scanning tunnelling microscopy (STM) simulation for the 1 ML coverage reveals the formation of Bi trimers for occupied states, and a honeycomb image for empty states. This result, together with the energetically unstable structure for 2/3 ML coverage, suggests that the experimentally observed STM image in the form of the honeycomb structure does not mean that the minimum energy configuration corresponds to Bi coverage of 2/3 ML, but rather represents current tunnelling into the empty states localized between Bi trimers for the milkstool model with 1 ML coverage.

  1. 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.

  2. Electron correlation in beryllium

    DEFF Research Database (Denmark)

    Omiste, Juan J.; Li, Wenliang; Madsen, Lars Bojer

    2017-01-01

    We apply a three-dimensional implementation of the time-dependent restricted-active-space self-consistent-field (TD-RASSCF) method to investigate effects of electron correlation in the ground state of Be as well as in its photoionization dynamics by short XUV pulses, including time delay in photo......We apply a three-dimensional implementation of the time-dependent restricted-active-space self-consistent-field (TD-RASSCF) method to investigate effects of electron correlation in the ground state of Be as well as in its photoionization dynamics by short XUV pulses, including time delay...... schemes, and in this way we identify the orbital spaces that are relevant for an accurate description of the photoelectron spectra. Finally, we investigate the effects of electron correlation on the magnitude of the relative Eisenbud-Wigner-Smith (EWS) time delay in the photoionization process into two...... different ionic channels. One channel, the ground-state channel in the ion, is accessible without electron correlation. The other channel is only accessible when including electron correlation. For theory beyond the mean-field time-dependent Hartree-Fock, the EWS time delay for the photon energy analyzed...

  3. 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

  4. NASA Electrical, Electronic and Electromechanical (EEE) Parts Assurance, An Overview

    Science.gov (United States)

    Label, Kenneth A.; Sampson, Michael J.

    2017-01-01

    This presentation will cover NASA Electrical, Electronic and Electromechanical (EEE) Parts Assurance Structure, NASA Electronic Parts and Packaging (NEPP) Program, NASA Electronic Parts Assurance Group (NEPAG), examples of assurance challenges, and future challenges.

  5. NASA STI Program Seminar: Electronic documents

    Science.gov (United States)

    1994-01-01

    The theme of this NASA Scientific and Technical Information Program Seminar was electronic documents. Topics covered included Electronic Documents Management at the CASI, the Impact of Electronic Publishing on User Expectations and Searching Image Record Management, Secondary Publisher Considerations for Electronic Journal Literature, and the Technical Manual Publishing On Demand System (TMPODS).

  6. Improving rainfall estimation from commercial microwave links using METEOSAT SEVIRI cloud cover information

    Science.gov (United States)

    Boose, Yvonne; Doumounia, Ali; Chwala, Christian; Moumouni, Sawadogo; Zougmoré, François; Kunstmann, Harald

    2017-04-01

    The number of rain gauges is declining worldwide. A recent promising method for alternative precipitation measurements is to derive rain rates from the attenuation of the microwave signal between remote antennas of mobile phone base stations, so called commercial microwave links (CMLs). In European countries, such as Germany, the CML technique can be used as a complementary method to the existing gauge and radar networks improving their products, for example, in mountainous terrain and urban areas. In West African countries, where a dense gauge or radar network is absent, the number of mobile phone users is rapidly increasing and so are the CML networks. Hence, the CML-derived precipitation measurements have high potential for applications such as flood warning and support of agricultural planning in this region. For typical CML bandwidths (10-40 GHz), the relationship of attenuation to rain rate is quasi-linear. However, also humidity, wet antennas or electronic noise can lead to signal interference. To distinguish these fluctuations from actual attenuation due to rain, a temporal wet (rain event occurred)/ dry (no rain event) classification is usually necessary. In dense CML networks this is possible by correlating neighboring CML time series. Another option is to use the correlation between signal time series of different frequencies or bidirectional signals. The CML network in rural areas is typically not dense enough for correlation analysis and often only one polarization and one frequency are available along a CML. In this work we therefore use cloud cover information derived from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) radiometer onboard the geostationary satellite METEOSAT for a wet (pixels along link are cloud covered)/ dry (no cloud along link) classification. We compare results for CMLs in Burkina Faso and Germany, which differ meteorologically (rain rate and duration, droplet size distributions) and technically (CML frequencies

  7. Practical analog electronics for technicians

    CERN Document Server

    Kimber, W A

    2013-01-01

    'Practical Analog Electronics for Technicians' not only provides an accessible introduction to electronics, but also supplies all the problems and practical activities needed to gain hands-on knowledge and experience. This emphasis on practice is surprisingly unusual in electronics texts, and has already gained Will Kimber popularity through the companion volume, 'Practical Digital Electronics for Technicians'. Written to cover the Advanced GNVQ optional unit in electronics, this book is also ideal for BTEC National, A-level electronics and City & Guilds courses. Together with 'Practical Digit

  8. Understand electrical and electronics maths

    CERN Document Server

    Bishop, Owen

    1993-01-01

    Understand Electrical and Electronics Maths covers elementary maths and the aspects of electronics. The book discusses basic maths including quotients, algebraic fractions, logarithms, types of equations and balancing of equations. The text also describes the main features and functions of graphs and the solutions to simpler types of electronics problems. The book then tackles the applications of polar coordinates in electronics, limits, differentiation and integration, and the applications of maths of rates of change in electronics. The activities of an electronic circuit; techniques of math

  9. Advances in electron transfer chemistry

    CERN Document Server

    Mariano, Patrick S

    1993-01-01

    Advances in Electron Transfer Chemistry, Volume 3 presents studies that discuss findings in the various aspects of electron chemistry. The book is comprised of four chapters; each chapter reviews a work that tackles an issue in electron transfer chemistry. Chapter 1 discusses the photoinduced electron transfer in flexible biaryl donor-acceptor molecules. Chapter 2 tackles light-induced electron transfer in inorganic systems in homogeneous and heterogeneous phases. The book also covers internal geometry relaxation effects on electron transfer rates of amino-centered systems. The sequential elec

  10. 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...

  11. 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

  12. 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

  13. 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.

  14. Quantum electronics basic theory

    CERN Document Server

    Fain, V M; Sanders, J H

    1969-01-01

    Quantum Electronics, Volume 1: Basic Theory is a condensed and generalized description of the many research and rapid progress done on the subject. It is translated from the Russian language. The volume describes the basic theory of quantum electronics, and shows how the concepts and equations followed in quantum electronics arise from the basic principles of theoretical physics. The book then briefly discusses the interaction of an electromagnetic field with matter. The text also covers the quantum theory of relaxation process when a quantum system approaches an equilibrium state, and explai

  15. Semiconductor opto-electronics

    CERN Document Server

    Moss, TS; Ellis, B

    1972-01-01

    Semiconductor Opto-Electronics focuses on opto-electronics, covering the basic physical phenomena and device behavior that arise from the interaction between electromagnetic radiation and electrons in a solid. The first nine chapters of this book are devoted to theoretical topics, discussing the interaction of electromagnetic waves with solids, dispersion theory and absorption processes, magneto-optical effects, and non-linear phenomena. Theories of photo-effects and photo-detectors are treated in detail, including the theories of radiation generation and the behavior of semiconductor lasers a

  16. VLSI electronics microstructure science

    CERN Document Server

    1982-01-01

    VLSI Electronics: Microstructure Science, Volume 4 reviews trends for the future of very large scale integration (VLSI) electronics and the scientific base that supports its development.This book discusses the silicon-on-insulator for VLSI and VHSIC, X-ray lithography, and transient response of electron transport in GaAs using the Monte Carlo method. The technology and manufacturing of high-density magnetic-bubble memories, metallic superlattices, challenge of education for VLSI, and impact of VLSI on medical signal processing are also elaborated. This text likewise covers the impact of VLSI t

  17. TIS - Beyond Electronic Mail.

    Science.gov (United States)

    1979-01-01

    AD-AI06 764 AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH F/G 17/2 TIS - BEYOND ELECTRONIC MAIL .(U) 1979 D L OLSON, N T FLYNN, M I DARWISH...79-22§1_ 4~~~~~~~ SIXi.m.aihl -- . TYPE OF REPORT & PERIOD covERED TIS -SBeyond Electronic Mail . TlSS~cnA~r 6 PEFRI4 O11G. REPORT NUMBER Duane L.A:o...single-service provisions of so-called " electronic mail ." Approaches to be used in implementing a TIS are considered, and a time-frame scenario is

  18. Electron microscope studies. Progress report, 1 July 1964--1 June 1992

    Energy Technology Data Exchange (ETDEWEB)

    Crewe, A.V.; Kapp, O.H.

    1992-07-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

  19. 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...

  20. 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.