Sample records for early decomposition observation

  1. Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography

    PubMed Central

    Lehtonen, Minna; Monahan, Philip J.; Poeppel, David

    2015-01-01

    Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked morphological priming with magneto-encephalography (MEG), a technique particularly adept at indexing processes involved in lexical access. The latency of an MEG component peaking, on average, 220 msec post-onset of the target in left occipito-temporal brain regions was found to be sensitive to the morphological prime– target relationship under masked priming conditions in a visual lexical decision task. Shorter latencies for related than unrelated conditions were observed both for semantically transparent (cleaner–CLEAN) and opaque (corner–CORN) prime–target pairs, but not for prime–target pairs with only an orthographic relationship (brothel–BROTH). These effects are likely to reflect a prelexical level of processing where form-based representations of stems and affixes are represented and are in contrast to models positing no morphological structure in lexical representations. Moreover, we present data regarding the transitional probability from stem to affix in a post hoc comparison, which suggests that this factor may modulate early morphological decomposition, particularly for opaque words. The timing of a robust MEG component sensitive to the morphological relatedness of prime–target pairs can be used to further understand the neural substrates and the time course of lexical processing. PMID:21557645

  2. Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography

    ERIC Educational Resources Information Center

    Lehtonen, Minna; Monahan, Philip J.; Poeppel, David

    2011-01-01

    Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked…

  3. Young Children's Thinking about Decomposition: Early Modeling Entrees to Complex Ideas in Science

    ERIC Educational Resources Information Center

    Ero-Tolliver, Isi; Lucas, Deborah; Schauble, Leona

    2013-01-01

    This study was part of a multi-year project on the development of elementary students' modeling approaches to understanding the life sciences. Twenty-three first grade students conducted a series of coordinated observations and investigations on decomposition, a topic that is rarely addressed in the early grades. The instruction included…

  4. Decomposition

    USGS Publications Warehouse

    Middleton, Beth A.

    2014-01-01

    A cornerstone of ecosystem ecology, decomposition was recognized as a fundamental process driving the exchange of energy in ecosystems by early ecologists such as Lindeman 1942 and Odum 1960). In the history of ecology, studies of decomposition were incorporated into the International Biological Program in the 1960s to compare the nature of organic matter breakdown in various ecosystem types. Such studies still have an important role in ecological studies of today. More recent refinements have brought debates on the relative role microbes, invertebrates and environment in the breakdown and release of carbon into the atmosphere, as well as how nutrient cycling, production and other ecosystem processes regulated by decomposition may shift with climate change. Therefore, this bibliography examines the primary literature related to organic matter breakdown, but it also explores topics in which decomposition plays a key supporting role including vegetation composition, latitudinal gradients, altered ecosystems, anthropogenic impacts, carbon storage, and climate change models. Knowledge of these topics is relevant to both the study of ecosystem ecology as well projections of future conditions for human societies.

  5. Evidence for Early Morphological Decomposition in Visual Word Recognition

    ERIC Educational Resources Information Center

    Solomyak, Olla; Marantz, Alec

    2010-01-01

    We employ a single-trial correlational MEG analysis technique to investigate early processing in the visual recognition of morphologically complex words. Three classes of affixed words were presented in a lexical decision task: free stems (e.g., taxable), bound roots (e.g., tolerable), and unique root words (e.g., vulnerable, the root of which…

  6. Evidence for Early Morphological Decomposition in Visual Word Recognition

    Microsoft Academic Search

    Olla Solomyak; Alec Marantz

    2010-01-01

    We employ a single-trial correlational MEG analysis technique to investigate early processing in the visual recognition of mor- phologically complex words. Three classes of affixed words were presented in a lexical decision task: free stems (e.g., taxable), bound roots (e.g., tolerable), and unique root words (e.g., vulner- able, the root of which does not appear elsewhere). Analysis was focused on

  7. Near-infrared surface photometry of early-type spiral galaxies: I. Bulge and disk decomposition

    E-print Network

    Giovanni Moriondo; Carlo Giovanardi; Leslie K. Hunt

    1998-02-11

    We present near-infrared (NIR) surface photometry of a sample of 14 early-type spirals with observed rotation curves. In this first paper, we report the results of two-dimensional parametric and non-parametric decompositions to separate the bulge and disk components; the parametric bulge is modeled with a generalized exponential law of integer index n, and the disk with a simple exponential. We find that the derived bulge parameters, for a given galaxy, vary systematically with the bulge shape index n. The mean early-type bulge has a best-fit n = 2.6, and 80% of the sample has best n of 2 or 3. Bulges are rarely spherical; the median bulge intrinsic ellipticity is 0.33. The median early-type disk has (J-K)_d more than 0.1 mag bluer than the bulge, and a NIR disk surface brightness more than 1 mag arcsec^{-2} brighter than later-type disks. Our data are consistent with the well-established correlation of both bulge and disk surface brightness with physical scale length, and we note that the location of bulges within this projection of the fundamental plane depends on their shape index n. In agreement with previous work, the ratios of bulge and disk scale lengths are consistent with a constant value r_e/r_d = 0.3; however, such value again depends on the bulge index n, implying that claims for a scale-free Hubble sequence may be premature.

  8. Phycobiliproteins and phycobilisomes: the early observations

    Microsoft Academic Search

    Nicole Tandeau de Marsac; URA CNRS

    2003-01-01

    The purpose of this minireview is to highlight the early observations that led to the discovery of the physico-chemical properties\\u000a of the phycobiliproteins, their structure and function, and to their architectural organization in supramolecular complexes,\\u000a the phycobilisomes. Generally attached on the stromal surface of the thylakoid membranes in both prokaryotic (cyanobacteria)\\u000a and eukaryotic cells (cyanelles, red algae and cryptomonads), these

  9. Polar decomposition for attitude determination from vector observations

    NASA Technical Reports Server (NTRS)

    Bar-Itzhack, Itzhack Y.

    1993-01-01

    This work treats the problem of weighted least squares fitting of a 3D Euclidean-coordinate transformation matrix to a set of unit vectors measured in the reference and transformed coordinates. A closed-form analytic solution to the problem is re-derived. The fact that the solution is the closest orthogonal matrix to some matrix defined on the measured vectors and their weights is clearly demonstrated. Several known algorithms for computing the analytic closed form solution are considered. An algorithm is discussed which is based on the polar decomposition of matrices into the closest unitary matrix to the decomposed matrix and a Hermitian matrix. A somewhat longer improved algorithm is suggested too. A comparison of several algorithms is carried out using simulated data as well as real data from the Upper Atmosphere Research Satellite. The comparison is based on accuracy and time consumption. It is concluded that the algorithms based on polar decomposition yield a simple although somewhat less accurate solution. The precision of the latter algorithms increase with the number of the measured vectors and with the accuracy of their measurement.

  10. Local Decomposition and Observability Properties for Automatic Calibration in Mobile Robotics

    E-print Network

    Paris-Sud XI, Université de

    been adopted in cooperative localization [10] and in SLAM [13]. Regarding calibration problems, it hasLocal Decomposition and Observability Properties for Automatic Calibration in Mobile Robotics Agostino Martinelli Abstract-- This paper considers the problem of sensor self- calibration in mobile

  11. Early diagenesis of vascular plant tissues: Lignin and cutin decomposition and biogeochemical implications

    NASA Astrophysics Data System (ADS)

    Opsahl, Stephen; Benner, Ronald

    1995-12-01

    Long-term subaqueous decomposition patterns of five different vascular plant tissues including mangrove leaves and wood ( Avicennia germinans), cypress needles and wood ( Taxodium distichum) and smooth cordgrass ( Spartina alternifora) were followed for a period of 4.0 years, representing the longest litter bag decomposition study to date. All tissues decomposed under identical conditions and final mass losses were 97, 68, 86, 39, and 93%, respectively. Analysis of the lignin component of herbaceous tissues using alkaline CuO oxidation was complicated by the presence of a substantial ester-bound phenol component composed primarily of cinnamyl phenols. To overcome this problem, we introduce a new parameter to represent lignin, ?6. ?6 is comprised only of the six syringyl and vanillyl phenols and was found to be much less sensitive to diagenetic variation than the commonly used parameter ?, which includes the cinnamyl phenols. Patterns of change in lignin content were strongly dependent on tissue type, ranging from 77% enrichment in smooth cordgrass to 6% depletion in cypress needles. In contrast, depletion of cutin was extensive (65-99%) in all herbaceous tissues. Despite these differences in the overall reactivity of lignin and cutin, both macromolecules were extensively degraded during the decomposition period. The long-term decomposition series also provided very useful information about the compositional parameters which are derived from the specific oxidation products of both lignin and cutin. The relative lability of ester-bound cinnamyl phenols compromised their use in parameters to distinguish woody from herbaceous plant debris. The dimer to monomer ratios of lignin-derived phenols indicated that most intermonomeric linkages in lignin degraded at similar rates. Acid to aldehyde ratios of vanillyl and syringyl phenols became elevated, particularly during the latter stages of decomposition supporting the use of these parameters as indicators of diagenetic alteration. Given the observation that cutin-derived source indicator parameters were generally more sensitive to diagenetic alteration than those of lignin, we suggest the distributional patterns of cutin-derived acids and their associated positional isomers may be most useful for tissue-specific distinctions complementing the general categorical information obtained from lignin phenol analysis alone.

  12. Early stages of spinodal decomposition in Fe-Cr resolved by in-situ small-angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Hörnqvist, M.; Thuvander, M.; Steuwer, A.; King, S.; Odqvist, J.; Hedström, P.

    2015-02-01

    In-situ, time-resolved small-angle neutron scattering (SANS) investigations of the early stages of the spinodal decomposition process in Fe-35Cr were performed at 773 and 798 K. The kinetics of the decomposition, both in terms of characteristic distance and peak intensity, followed a power-law behaviour from the start of the heat treatment (a'= 0.10-0.11 and a? = 0.67-0.86). Furthermore, the method allows tracking of the high-Q slope, which is a sensitive measure of the early stages of decomposition. Ex-situ SANS and atom probe tomography were used to verify the results from the in-situ investigations. Finally, the in-situ measurement of the evolution of the characteristic distance at 773 K was compared with the predictions from the Cahn-Hilliard-Cook model, which showed good agreement with the experimental data (a'= 0.12-0.20 depending on the assumed mobility).

  13. Observations on the Early Childhood Profession.

    ERIC Educational Resources Information Center

    Levine, Michael

    1992-01-01

    Comments on where the early childhood profession stands, where it should go, and how organizations like the National Association for the Education of Young Children (NAEYC) can move the field ahead. Discusses two strategies early childhood educators can pursue to improve compensation in the next 5 to 10 years: defining quality as an issue of…

  14. Early Observations of Sunspots: Scheiner and Galileo

    NASA Astrophysics Data System (ADS)

    Casanovas, J.

    There had been occasional observations of spots on the Sun since antiquity. Kepler observed a sunspot in 1607 but he interpreted it as a Mercury's transit. One year after the introduction of the telescope astronomers identified spots on the Sun. J. Fabricius was the first to print a book on sunspots at the end of 1611, but this book had little diffusion. Fabricius rightly thought that the spots belonged to the Sun. The Jesuit C. Scheiner independently observed sunspots on the Sun and he announced his discovery at the end of 1611 in three letters under the pseudonym Apelles. Scheiner failed to observe the returning of the spots and hence did not recognize the solar rotation. Therefore he preferred to see the spots as caused by little bodies orbiting the Sun. Based on Scheiner's observations, Kepler concluded that the spots were on the solar surface like dross floating on melted metal. When Scheiner's letters reached Italy, Galileo claimed to have observed sunspots much earlier, but if this had been the case, he had not published anything on sunspots. Galileo replied to Apelles' letters affirming that the spots were on the surface of the Sun, like clouds. A bitter and long fight followed between Galileo and Scheiner on the priority of discovery. Techniques for solar observation progressed quickly. The solar image was observed projected on a white paper for measurement of sunspots positions. Scheiner later perfected this method installing the telescope on an equatorial mounting. Scheiner made over 2000 solar observations and determined the orientation of the solar axis of rotation. His methods and results were presented in his monumental work Rosa Ursina.

  15. Unimolecular thermal decomposition of phenol and d5-phenol: Direct observation of cyclopentadiene formation via cyclohexadienone

    NASA Astrophysics Data System (ADS)

    Scheer, Adam M.; Mukarakate, Calvin; Robichaud, David J.; Nimlos, Mark R.; Carstensen, Hans-Heinrich; Barney Ellison, G.

    2012-01-01

    The pyrolyses of phenol and d5-phenol (C6H5OH and C6D5OH) have been studied using a high temperature, microtubular (?tubular) SiC reactor. Product detection is via both photon ionization (10.487 eV) time-of-flight mass spectrometry and matrix isolation infrared spectroscopy. Gas exiting the heated reactor (375 K-1575 K) is subject to a free expansion after a residence time in the ?tubular reactor of approximately 50-100 ?s. The expansion from the reactor into vacuum rapidly cools the gas mixture and allows the detection of radicals and other highly reactive intermediates. We find that the initial decomposition steps at the onset of phenol pyrolysis are enol/keto tautomerization to form cyclohexadienone followed by decarbonylation to produce cyclopentadiene; C6H5OH ? c-C6H6 = O ? c-C5H6 + CO. The cyclopentadiene loses a H atom to generate the cyclopentadienyl radical which further decomposes to acetylene and propargyl radical; c-C5H6 ? c-C5H5 + H ? HC?CH + HCCCH2. At higher temperatures, hydrogen loss from the PhO-H group to form phenoxy radical followed by CO ejection to generate the cyclopentadienyl radical likely contributes to the product distribution; C6H5O-H ? C6H5O + H ? c-C5H5 + CO. The direct decarbonylation reaction remains an important channel in the thermal decomposition mechanisms of the dihydroxybenzenes. Both catechol (o-HO-C6H4-OH) and hydroquinone (p-HO-C6H4-OH) are shown to undergo decarbonylation at the onset of pyrolysis to form hydroxycyclopentadiene. In the case of catechol, we observe that water loss is also an important decomposition channel at the onset of pyrolysis.

  16. Decomposition of the wind and nonwind effects on observed year-to-year air quality variation

    NASA Astrophysics Data System (ADS)

    Li, Ying; Lau, Alexis; Wong, Agnes; Fung, Jimmy

    2014-05-01

    Changes in emissions and wind are often identified as the two dominant factors contributing to year-to-year variations in the concentration of primary pollutants. However, because changes in wind and emissions are intertwined, it has been difficult to quantitatively differentiate their effects on air quality directly from observed data. In particular, if the annual mean concentration of pollutants is higher than the previous year, it is difficult to identify whether the deterioration in air quality is caused by wind blowing from more polluted regions or an increase in contributing emissions. In this paper, based on wind and pollution roses, we propose a method to differentiate the effects of wind and nonwind (e.g., emissions) changes using direct observation. An index (L) is first defined to quantify the validity of the linear decomposition. The method is then validated by idealized experiments, numerical experiments, and a 2 year observation data set from an actual emissions control program. Finally, we demonstrate the proposed method by studying long-term particulate matter (PM10) variations in Hong Kong during 2000-2011. We find that for most of the period, the linear decomposition of the changes in annual PM10 is valid (up to 90% confidence) and is dominated by the change in nonwind effects (e.g., emissions), whereas the average absolute effect from the wind variability is about 20%. Sensitivity analyses also suggest that our method should work in any location as long as the observed wind and pollution data have sufficient duration and resolution to resolve the corresponding wind and pollution roses.

  17. Indium hydroxide to oxide decomposition observed in one nanocrystal during in situ transmission electron microscopy studies

    SciTech Connect

    Miehe, Gerhard; Lauterbach, Stefan; Kleebe, Hans-Joachim [Technische Universitaet Darmstadt, Fachbereich Material- und Geowissenschaften, Petersenstr. 23, 64287 Darmstadt (Germany)] [Technische Universitaet Darmstadt, Fachbereich Material- und Geowissenschaften, Petersenstr. 23, 64287 Darmstadt (Germany); Gurlo, Aleksander, E-mail: gurlo@materials.tu-darmstadt.de [Technische Universitaet Darmstadt, Fachbereich Material- und Geowissenschaften, Petersenstr. 23, 64287 Darmstadt (Germany)] [Technische Universitaet Darmstadt, Fachbereich Material- und Geowissenschaften, Petersenstr. 23, 64287 Darmstadt (Germany)

    2013-02-15

    The high-resolution transmission electron microscopy (HR-TEM) is used to study, in situ, spatially resolved decomposition in individual nanocrystals of metal hydroxides and oxyhydroxides. This case study reports on the decomposition of indium hydroxide (c-In(OH){sub 3}) to bixbyite-type indium oxide (c-In{sub 2}O{sub 3}). The electron beam is focused onto a single cube-shaped In(OH){sub 3} crystal of {l_brace}100{r_brace} morphology with ca. 35 nm edge length and a sequence of HR-TEM images was recorded during electron beam irradiation. The frame-by-frame analysis of video sequences allows for the in situ, time-resolved observation of the shape and orientation of the transformed crystals, which in turn enables the evaluation of the kinetics of c-In{sub 2}O{sub 3} crystallization. Supplementary material (video of the transformation) related to this article can be found online at (10.1016/j.jssc.2012.09.022). After irradiation the shape of the parent cube-shaped crystal is preserved, however, its linear dimension (edge) is reduced by the factor 1.20. The corresponding spotted selected area electron diffraction (SAED) pattern representing zone [001] of c-In(OH){sub 3} is transformed to a diffuse strongly textured ring-like pattern of c-In{sub 2}O{sub 3} that indicates the transformed cube is no longer a single crystal but is disintegrated into individual c-In{sub 2}O{sub 3} domains with the size of about 5-10 nm. The induction time of approximately 15 s is estimated from the time-resolved Fourier transforms. The volume fraction of the transformed phase (c-In{sub 2}O{sub 3}), calculated from the shrinkage of the parent c-In(OH){sub 3} crystal in the recorded HR-TEM images, is used as a measure of the kinetics of c-In{sub 2}O{sub 3} crystallization within the framework of Avrami-Erofeev formalism. The Avrami exponent of {approx}3 is characteristic for a reaction mechanism with fast nucleation at the beginning of the reaction and subsequent three-dimensional growth of nuclei with a constant growth rate. The structural transformation path in reconstructive decomposition of c-In(OH){sub 3} to c-In{sub 2}O{sub 3} is discussed in terms of (i) the displacement of hydrogen atoms that lead to breaking the hydrogen bond between OH groups of [In(OH){sub 6}] octahedra and finally to their destabilization and (ii) transformation of the vertices-shared indium-oxygen octahedra in c-In(OH){sub 3} to vertices- and edge-shared octahedra in c-In{sub 2}O{sub 3}. - Graphical abstract: Frame-by-frame analysis of video sequences recorded of HR-TEM images reveals that a single cube-shaped In(OH){sub 3} nanocrystal with {l_brace}100{r_brace} morphology decomposes into bixbyite-type In{sub 2}O{sub 3} domains while being imaged. The mechanism of this decomposition is evaluated through the analysis of the structural relationship between initial (c-In(OH){sub 3}) and transformed (c-In{sub 2}O{sub 3}) phases and though the kinetics of the decomposition followed via the time-resolved shrinkage of the initial crystal of indium hydroxide. Highlights: Black-Right-Pointing-Pointer In-situ time-resolved High Resolution Transmission Electron Microscopy. Black-Right-Pointing-Pointer Crystallographic transformation path. Black-Right-Pointing-Pointer Kinetics of the decomposition in one nanocrystal.

  18. Decomposition of Fe5C2 catalyst particles in carbon nanofibers during TEM observation

    NASA Astrophysics Data System (ADS)

    Blank, Vladimir D.; Kulnitskiy, Boris A.; Perezhogin, Igor A.; Alshevskiy, Yuriy L.; Kazennov, Nikita V.

    2009-01-01

    The effect of an electron beam on nanoparticles of two Fe carbide catalysts inside a carbon nanofiber was investigated in a transmission electron microscope. Electron beam exposure does not result in significant changes for cementite (?-Fe3C). However, for Hägg carbide nanoparticles (?-Fe5C2), explosive decay is observed after exposure for 5-10 s. This produces small particles of cementite and ?-Fe, each covered with a multilayer carbon shell, and significantly modifies the carbon-fiber structure. It is considered that the decomposition of Hägg carbide is mostly due to the damage induced by high-energy electron collisions with the crystal lattice, accompanied by the heating of the particle and by mechanical stress provided by the carbon layers of the nanofiber.

  19. An observation on the decomposition process of gasoline-ingested monkey carcasses in a secondary forest in Malaysia.

    PubMed

    Rumiza, A R; Khairul, O; Zuha, R M; Heo, C C

    2010-12-01

    This study was designed to mimic homicide or suicide cases using gasoline. Six adult long-tailed macaque (Macaca fascicularis), weighing between 2.5 to 4.0 kg, were equally divided into control and test groups. The control group was sacrificed by a lethal dose of phenobarbital intracardiac while test group was force fed with two doses of gasoline LD50 (37.7 ml/kg) after sedation with phenobarbital. All carcasses were then placed in a decomposition site to observe the decomposition and invasion process of cadaveric fauna on the carcasses. A total of five decomposition stages were recognized during this study. This study was performed during July 2007. Fresh stage of control and test carcasses occurred between 0 to 15 and 0 to 39 hours of exposure, respectively. The subsequent decomposition stages also exhibited the similar pattern whereby the decomposition process of control carcasses were faster than tested one. The first larvae were found on control carcasses after 9 hours of death while the test group carcasses had only their first blowfly eggs after 15 hours of exposure. Blow flies, Achoetandrus rufifacies and Chrysomya megacephala were the most dominant invader of both carcasses throughout the decaying process. Diptera collected from control carcasses comprised of scuttle fly, Megaselia scalaris and flesh fly, sarcophagid. We concluded that the presence of gasoline and its odor on the carcass had delayed the arrival of insect to the carcasses, thereby slowing down the decomposition process in the carcass by 6 hours. PMID:21399577

  20. Observation of spheroidal normal mode multiplets below 1 mHz using ensemble empirical mode decomposition

    NASA Astrophysics Data System (ADS)

    Shen, Wen-Bin; Ding, Hao

    2014-03-01

    Superconducting gravimeter (SG) records after the 2004 Sumatra Mw 9.0, 2010 Maule Mw 8.8 and 2011 Tohoku Mw 9.1 earthquakes are selected to observe the singlets of six spheroidal normal mode multiplets below 1 mHz (0S2, 2S1, 0S3, 0S4, 1S2 and 3S1). To clearly observe their spectral splitting, the ensemble empirical mode decomposition (EEMD) is applied to SG records as a dyadic filter bank. Comparisons of the product spectra obtained from the direct residual gravity records and those obtained after using EEMD clearly confirm the validity of EEMD. After using EEMD, all of the singlets of the six multiplets, particularly those of 0S4 and 1S2, are completely observed with high signal-to-noise ratio, whereas some of singlets could not be well resolved without the application of EEMD. This study demonstrates that EEMD may be important in the detection of the splitting of some weak and low-frequency seismic modes. The relevant observation results may improve the Earth's density models.

  1. Application of Spectral Decomposition Techniques in the Assessment and Intercomparison of Models and Observations

    NASA Astrophysics Data System (ADS)

    Carlson, B. E.; Li, J.; Lacis, A. A.

    2014-12-01

    In the assessment of models using observations, or the intercomparison between different observational datasets, it is necessary to examine the coherency in the spatial and temporal variability present in different datasets. Meanwhile, global datasets are always high dimensional, therefore efficient comparison is not an easy task. In this study, we apply several spectral decomposition techniques, namely Combined Principal Component Analysis (CPCA) and Combined Maximum Covariance Analysis (CMCA), as effective means to reduce data dimension and extract the dominant variability. More importantly, these methods find the common modes of variability in different datasets, therefore allowing parallel comparison and evaluation. These methods were applied to the AOD fields from fifteen CMIP5 models and three observational datasets: MODIS, MISR and AERONET. We focus on large-scale features including the spatial distribution, seasonality and long term trends. Results show that while models qualitatively agree with observations, significant regional differences still exist, especially in regions with mixed aerosol types such as the Sahel, North India and East Asia. Compared with observations, models in general lack interannual variability. Moreover, all models indicate consistent AOD trends with increases over East Asia and decreases over East US and Europe. However, the AOD trends over these regions are not very significant in the observations Instead, a significant increase in dust concentrations over the Arabian Peninsula and a significant decrease over the biomass burning regions of South America are found in MODIS and MISR. The aerosol composition for the regions with largest disagreement is also examined. Figure caption: The dominant mode of CMCA analysis using fifteen CMIP5 models and MODIS, MISR and AERONET. The color of the circles indicate the signal of AERONET. This mode is associated with a summer-winter seasonal cycle and models agree qualitatively with observations.

  2. Observational evidence for AGN feedback in early-type galaxies

    E-print Network

    Schawinski, Kevin; Sarzi, Marc; Maraston, Claudia; Kaviraj, Sugata; Joo, Seok-Joo; Yi, Sukyoung K; Silk, Joseph

    2007-01-01

    A major amendment in recent models of hierarchical galaxy formation is the inclusion of so-called AGN feedback. The energy input from an active central massive black hole is invoked to suppress star formation in early-type galaxies at later epochs. A major problem is that this process is poorly understood, and compelling observational evidence for its mere existence is still missing. In search for signatures of AGN feedback, we have compiled a sample of 16,000 early-type galaxies in the redshift range 0.05visual inspection which produces a sample that is not biased against recent star formation and nuclear activity. The objects with emission (~20 per cent) are offset from the red sequence and form a well-defined pattern in the colour-mass diagram. Star forming early-types inhabit the blue cloud, while early-types with AGN are located considerably closer to and almost on the red sequence. S...

  3. Constraining Perturbative Early Dark Energy with Current Observations

    Microsoft Academic Search

    Ujjaini Alam; Ujjaini

    2010-01-01

    In this work, we study a class of early dark energy (EDE) models, in which, unlike in standard dark energy models, a substantial amount of dark energy exists in the matter-dominated era. We self-consistently include dark energy perturbations, and constrain these models using current observations. We consider EDE models in which the dark energy equation of state is at least

  4. Direct observation of roaming radicals in the thermal decomposition of acetaldehyde.

    SciTech Connect

    Sivaramakrishnan, R.; Michael, J. V.; Klippenstein, S. J.; Chemical Sciences and Engineering Division

    2010-01-21

    The thermal dissociation of acetaldehyde has been studied with the reflected shock tube technique using H(D)-atom atomic resonance absorption spectrometry detection. The use of an unreversed light source yields extraordinarily sensitive H atom detection. As a result, we are able to measure both the total decomposition rate and the branching to radical versus molecular channels. This branching provides a direct measure of the contribution from the roaming radical mechanism since the contributions from the usual tight transition states are predicted by theory to be negligible. The experimental observations also provide a measure of the rate coefficient for H + CH{sub 3}CHO. Another set of experiments employing C{sub 2}H{sub 5}I as an H-atom source provides additional data for this rate coefficient that extends to lower temperature. An evaluation of the available experimental results for H + CH{sub 3}CHO can be expressed by a three-parameter Arrhenius expression as k = 7.66 x 10{sup -20}T{sup 2.75} exp((-486 K)/T) cm{sup 3} molecule{sup -1} s{sup -1} (298-1415 K). Analogous experiments employing C{sub 2}D{sub 5}I as a D-atom source allow for the study of the isotopically substituted reaction. The present experiments are the only direct measure for this reaction rate constant, and the results can be expressed by an Arrhenius expression as k = 5.20 x 10{sup -10} exp((-4430 K)/T) cm{sup 3} molecule{sup -1} s{sup -1} (1151-1354 K). The H/D + CH{sub 3}CHO reactions are also studied with ab initio transition-state theory, and the results are in remarkably good agreement with the current experimental data.

  5. Observational evidence for AGN feedback in early-type galaxies

    NASA Astrophysics Data System (ADS)

    Schawinski, Kevin; Thomas, Daniel; Sarzi, Marc; Maraston, Claudia; Kaviraj, Sugata; Joo, Seok-Joo; Yi, Sukyoung K.; Silk, Joseph

    2007-12-01

    A major amendment in recent models of hierarchical galaxy formation is the inclusion of so-called active galactic nucleus (AGN) feedback. The energy input from an active central massive black hole is invoked to suppress star formation in early-type galaxies at later epochs. A major problem is that this process is poorly understood, and compelling observational evidence for its mere existence is still missing. In search for signatures of AGN feedback, we have compiled a sample of 16000 early-type galaxies in the redshift range 0.05 < z < 0.1 from the Sloan Digital Sky Survey (SDSS) data base (MOSES: Morphologically Selected Ellipticals in SDSS). Key in our approach is the use of a purely morphological selection criterion through visual inspection which produces a sample that is not biased against recent star formation and nuclear activity. Based on the nebular emission-line characteristics we separate between star formation activity, black hole activity, the composite of the two and quiescence. We find that emission is mostly LINER (low ionization nuclear emission line region) like in high-mass galaxies (? > 200kms-1) and roughly evenly distributed between star formation and AGN at intermediate and low (? < 100kms-1) masses. The objects with emission (~20 per cent) are offset from the red sequence and form a well-defined pattern in the colour-mass diagram. Star-forming early-types inhabit the blue cloud, while early-types with AGN are located considerably closer to and almost on the red sequence. Star formation-AGN composites are found right between these two extremes. We further derive galaxy star formation histories using a novel method that combines multiwavelength photometry from near-ultraviolet (UV) to near-infrared (IR) and stellar absorption indices. We find that in those objects deviating from the red sequence star formation occurred several 100Myr in the past involving 1-10per cent of the total stellar mass. We identify an evolutionary sequence from star formation via nuclear activity to quiescence. This transition process lasts about 1Gyr, and the peak AGN phase occurs roughly half a Gyr after the starburst. The most likely interpretation is that star formation is suppressed by nuclear activity in these objects before they settle on the red sequence. This is empirical evidence for the occurrence of AGN feedback in early-type galaxies at recent epochs.

  6. "Learning Stories"--Crossing Borders: Introducing Qualitative Early Childhood Observation Techniques to Early Childhood Practitioners in Saudi Arabia

    ERIC Educational Resources Information Center

    Nyland, Berenice; Alfayez, Shatha

    2012-01-01

    Early childhood education has become a focus of government policy across the world. Part of the present increased interest in early childhood education has been a focus on curriculum frameworks and socio/cultural methods of assessment. Currently, New Zealand has emerged as a world leader in early childhood education, and observation and assessment…

  7. Early Hinode Observations of a Solar Filament Eruption

    NASA Technical Reports Server (NTRS)

    Sterling, Alphonse C.; Moore, Ronald L.

    2007-01-01

    We use Hinode X-Ray Telescope (XRT) and Solar Optical Telescope (SOT) filtergraph (FG) Stokes-V magnetogram observations to study the early onset of a solar eruption that includes an erupting filament that we observe in TRACE EUV images; this is one of the first filament eruptions seen with Hinode. The filament undergoes a slow rise for at least 30 min prior to its fast eruption and strong soft X-ray flaring, and the new Hinode data elucidate the physical processes occurring during the slow-rise period: During the slow-rise phase, a soft X-ray (SXR) sigmoid forms from apparent reconnection low in the sheared core field traced by the filament, and there is a low-level intensity peak in both EUV and SXRs during the slow rise. The SOT data show that magnetic flux cancellation occurs along the neutral line of the filament in the hours before eruption, and this likely caused the low-lying reconnection that produced the microflaring and the slow rise leading up to the eruption.

  8. The stellar mass distribution in early-type disk galaxies: surface photometry and bulge-disk decompositions

    E-print Network

    E. Noordermeer; J. M. van der Hulst

    2007-01-25

    We present deep B- and R-band surface photometry for a sample of 21 galaxies with morphological types between S0 and Sab. We present radial profiles of surface brightness, colour, ellipticity, position angle and deviations of axisymmetry for all galaxies, as well as isophotal and effective radii and total magnitudes. We have decomposed the images into contributions from a spheroidal bulge and a flat disk, using an interactive, 2D decomposition technique. We study in detail the relations between various bulge and disk parameters. In particular, we find that the bulges of our galaxies have surface brightness profiles ranging from exponential to De Vaucouleurs, with the average value of the Sersic shape parameter n being 2.5. In agreement with previous studies, we find that the shape of the bulge intensity distribution depends on luminosity, with the more luminous bulges having more centrally peaked light profiles. By comparing the ellipticity of the isophotes in the bulges to those in the outer, disk dominated regions, we are able to derive the intrinsic axis ratio q_b of the bulges. The average axis ratio is 0.55, with an rms spread of 0.12. None of the bulges in our sample is spherical, whereas in some cases, the bulges can be as flat as q_b = 0.3 - 0.4. The bulge flattening seems to be weakly coupled to luminosity, more luminous bulges being on average slightly more flattened than their lower-luminosity counterparts. Our finding that most bulges are significantly flattened and have an intensity profile shallower than R^{1/4} suggests that `pseudobulges', formed from disk material by secular processes, do not only occur in late-type spiral galaxies, but are a common feature in early-type disk galaxies as well. (abridged)

  9. Implementing Observation Protocols: Lessons for K-12 Education from the Field of Early Childhood

    ERIC Educational Resources Information Center

    Pianta, Robert C.

    2012-01-01

    This report draws from decades of experience using observation in early childhood education, which has implications for administrative decisions, evaluation practices, and policymaking in K-12. Early childhood education has long embraced the value of observing classrooms and teacher-child interactions. In early childhood education the features of…

  10. Self-healing slip pulses driven by thermal decomposition: Towards identifying dynamic weakening mechanisms in seismic observations

    NASA Astrophysics Data System (ADS)

    Platt, J. D.; Viesca, R. C.; Garagash, D.

    2012-12-01

    Seismological observations indicate that earthquake ruptures commonly propagate as self-healing slip pulses, with slip duration at any location on the fault being much shorter than the total event duration [Heaton 1990]. Theoretical work has linked these slip pulses to low values of the background driving stress on the fault [Zheng and Rice 1998]. Recent experiments [Han et al. 2007;Brantut et al. 2008] have shown that fault materials may thermally decompose during shear. These endothermic reactions release pore fluid, leading to an increase in pore pressure and a decrease in temperature [Sulem and Famin 2009]. An Arrhenius kinetic controls the reaction rate, and dynamic weakening only occurs when the temperature reaches a critical temperature triggering the reaction. This abrupt change is in sharp contrast with thermal pressurization where the pore pressure increases smoothly with slip. Previous theoretical studies of thermal decomposition have focused on simple mechanical systems with imposed slip rates [Sulem and Famin 2009], or coupling to a spring-slider model [Brantut et al. 2011]. We present the first solutions to couple thermal decomposition with dynamic rupture, extending the model in Garagash [2012] to solve for self-healing slip pulses. For a range of driving stresses there are two possible slip pulses, compared with a single solution for thermal pressurization alone. One solution corresponds to small slip and a low temperature rise that precludes the reaction; the other is a larger slip solution with weakening due to thermal pressurization at the rupture tip, and weakening due to thermal decomposition in the middle of the pulse. A dramatic drop in fault strength accompanies the onset of the reaction, leading to peak slip rates coinciding with the onset of the reaction. For thermal pressurization alone the maximum strain rate always occurs at the rupture tip, and depends sensitively on the driving stress. Thermal decomposition is identified by slower rupture speeds, longer slip duration and more dramatic strength drops. The peak slip rates occur away from the rupture tip, and are insensitive to changes in the driving stress. For deeper events the ambient temperature is higher, causing the reaction to initiate earlier, and the peak slip rate to move towards the rupture tip. Often the total slip in a pulse is linked to a critical slip required to activate the reaction, suggesting a decrease in slip with depth. Our results could also be linked to observed variations in fault zone mineralogy, with different reactions activated on different faults. Since the peak slip rate is achieved at the onset of reaction, maximum pore pressure generation by thermal pressurization coincides with the maximum generation by thermal decomposition, leading to pore pressures exceeding the normal compressive stress on the fault. One possible mechanism to cap the pore pressure is to allow the permeability to increase with the pore pressure [Wibberley and Shimamoto 2003], enhancing healing by hydraulic diffusion at the trailing edge of the pulse. This leads to slip pulses with shorter slip durations and higher rupture velocities.

  11. Cumulus clouds - Early aircraft observations and entrainment hypotheses

    NASA Technical Reports Server (NTRS)

    Simpson, J.

    1983-01-01

    The history of cumulus research in the decade following World War II is reviewed in the perspective of the new ideas and advances made during the subsequent generation. Emphasis is placed upon pioneering aircraft measurements, evidence for entrainment, the early model attempts and their attendant controversies.

  12. Peer Observation of Teaching: Reflections of an Early Career Academic

    ERIC Educational Resources Information Center

    Eri, Rajaraman

    2014-01-01

    Peer observation of teaching (POT) is a reciprocal process where a peer observes another's teaching (classroom, virtual, on-line or even teaching resource such as unit outlines, assignments). Peers then provide constructive feedbacks that would enable teaching professional development through the mirror of critical reflection by both the observer…

  13. Innovation in observation: a vision for early outbreak detection

    PubMed Central

    Fefferman, NH; Naumova, EN

    2010-01-01

    The emergence of new infections and resurgence of old ones—health threats stemming from environmental contamination or purposeful acts of bioterrorism—call for a worldwide effort in improving early outbreak detection, with the goal of ameliorating current and future risks. In some cases, the problem of outbreak detection is logistically straightforward and mathematically easy: a single case of a disease of great concern can constitute an outbreak. However, for the vast majority of maladies, a simple analytical solution does not exist. Furthermore, each step in developing reliable, sensitive, effective surveillance systems demonstrates enormous complexities in the transmission, manifestation, detection, and control of emerging health threats. In this communication, we explore potential future innovations in early outbreak detection systems that can overcome the pitfalls of current surveillance. We believe that modern advances in assembling data, techniques for collating and processing information, and technology that enables integrated analysis will facilitate a new paradigm in outbreak definition and detection. We anticipate that moving forward in this direction will provide the highly desired sensitivity and specificity in early detection required to meet the emerging challenges of global disease surveillance. PMID:22460396

  14. In situ transmission electron microscopy observation of the decomposition of MgH 2 nanofiber

    Microsoft Academic Search

    Chunyu Zhu; Norihito Sakaguchi; Sou Hosokai; Seiichi Watanabe; Tomohiro Akiyama

    2011-01-01

    In this paper, we presented an investigation of the phase transformation of MgH2 to Mg, in which a sample of a single-crystal MgH2 nanofiber was prepared by hydriding chemical vapor deposition (HCVD) and observed by in situ (high-resolution) transmission electron microscopy (TEM). The results indicated that the orientation relationship between MgH2 and Mg during the phase change was: one of

  15. Observable relic features of soliton stars from early Universe.

    NASA Astrophysics Data System (ADS)

    Chiu, Hong-Yee

    Nontopological soliton stars belong to a wide class of stable extended objects characterized by a conserved charge (such as the net number of particles). The author discusses the time evolution of one particular model due to Lee and Pang. Radiation from soliton stars mix with the black body background radiation of the Universe, and if not thermalized, it may cause a small distortion in the short wavelength end of the observed cosmic background radiation. These distortions may be observed as spatial inhomogeneities in the short wavelength end.

  16. Hubble and Shapley - Two Early Giants of Observational Cosmology

    NASA Astrophysics Data System (ADS)

    van den Bergh, Sidney

    2011-12-01

    Observational cosmology of the first decades of the Twentieth Century was dominated by two giants: Edwin Hubble and Harlow Shapley. Hubble's major contributions were to the study and classification of individual galaxies with large telescopes, whereas Shapley is best remembered for his work on groups and clusters of galaxies using telescopes of more modest aperture.

  17. Early SDO/HMI Magnetic Field Observations (Invited)

    NASA Astrophysics Data System (ADS)

    Hoeksema, J. T.; Hmi Magnetic Field Team

    2010-12-01

    Solar magnetic features no longer have any expectation of privacy and understanding the Sun’s magnetic field is the key to space weather prediction. The Helioseismic and Magnetic Imager on the Solar Dynamics Observatory measures polarized line profiles that measure both line-of-sight and vector magnetic fields in the photosphere. The longitudinal field is measured every 45 seconds with filtergrams from the same camera used to determine the velocity. The Stokes parameters are calculated from a longer sequence taken with a second 4096 x 4096 CCD. Inversion and disambiguation provide an estimate of the vector magnetic field components and uncertainties at least every 12 minutes in active regions. Full disk synoptic observations began in April and magnetograms are available shortly after they are observed from jsoc.stanford.edu along with a plethora of other useful magnetic field products. The low-noise line-of-sight measurements compare favorably with MDI and GONG. The vector field is being compared with other observations and appears quite stable, even in small strong-field concentrations outside of active regions. Scattered light is low and the sensitivity is very good. HMI observes the entire disk all of the time, so any feature of interest can be tracked during its entire disk passage without interruption. Knowing the detailed time development will lead to better understanding of energy storage and release in the atmosphere above and what leads to the spectacular events detected by AIA, EVE, and other instruments.

  18. Exploring A Decomposition Community

    NSDL National Science Digital Library

    LaRae Mikkelson, Ellen Hopkins Elementary, Moorhead, MN

    2012-03-19

    In this classroom lab setting, students will construct Decomposition Columns from two-liter plastic bottles. Students will gather organic material and observe activity in the column. Students will record observations and construction steps in their science notebook.

  19. Longitudinal analyses of early lesions by fluorescence: an observational study.

    PubMed

    Ferreira Zandoná, A; Ando, M; Gomez, G F; Garcia-Corretjer, M; Eckert, G J; Santiago, E; Katz, B P; Zero, D T

    2013-07-01

    Previous caries experience correlates to future caries risk; thus, early identification of lesions has importance for risk assessment and management. In this study, we aimed to determine if Quantitative Light-induced Fluorescence (QLF) parameters--area (A [mm(2)]), fluorescence loss (F [%]), and Q [% × mm(2)]--obtained by image analyses can predict lesion progression. We secured consent from 565 children (from 5-13 years old) and their parents/guardians and examined them at baseline and regular intervals over 48 months according to the International Caries Detection Assessment System (ICDAS), yearly radiographs, and QLF. QLF images from surfaces with ICDAS 0/1/2/3/4 at baseline that progressed (N = 2,191) to cavitation (ICDAS 5/6) or fillings and surfaces that did not progress to cavitation/fillings (N = 4,141) were analyzed independently for A, F, and Q. Linear mixed-effects models were used to compare means and slopes (changes over time) between surfaces that progressed and those that did not. QLF A, F, and Q increased at a faster rate for surfaces that progressed than for surfaces that did not progress (p = .0001), regardless of type of surface or baseline ICDAS score. AUC for ICDAS ranged from 0.65 to 0.80, but adding QLF information improved AUC (0.82-0.87, p < .0005). We concluded that faster changes in QLF variables can indicate lesion progression toward cavitation and be more clinically relevant than actual QLF values. PMID:23690351

  20. EARLY ULTRAVIOLET OBSERVATIONS OF A TYPE IIn SUPERNOVA (2007pk)

    SciTech Connect

    Pritchard, T. A.; Roming, P. W. A. [Department of Astronomy and Astrophysics, Penn State University, 525 Davey Lab, University Park, PA 16802 (United States); Brown, P. J. [Department of Physics and Astronomy, University of Utah, 115 South 1400 East 201, Salt Lake City, UT (United States); Kuin, N. P. M.; Oates, S. R. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Bayless, Amanda J. [Southwest Research Institute, Department of Space Science, 6220 Culebra Rd, San Antonio, TX 78238 (United States); Holland, S. T. [Center for Research and Exploration in Space Science and Technology, NASA/GSFC, Greenbelt, MD 20771 (United States); Immler, S. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Milne, P., E-mail: proming@swri.edu [Steward Observatory, 933 North Cherry Avenue, RM N204, Tucson, AZ 85721 (United States)

    2012-05-10

    We present some of the earliest UV observations of a Type IIn supernova (SN)-SN 2007pk, where UV and optical observations using Swift's Ultra-Violet/Optical Telescope began 3 days after discovery or {approx}5 days after shock breakout. The SN observations commence at approximately maximum light in the UV and u-band filters, suggesting that the UV light curve peaks begin very rapidly after the initial explosion, and subsequently exhibit a linear decay of 0.20, 0.21, 0.16 mag day{sup -1} in the UVOT uvw2, uvm2, uvw1 ({lambda}{sub c} = 1928, 2246, 2600 Angstrom-Sign ) filters. Meanwhile the b- and v-band light curves begin approximately seven days before v-band peak and exhibit a shallow rise followed by a subsequent decay. A series of optical/near-IR spectra taken with the Hobby-Eberly Telescope at days 3-26 after discovery show spectra similar to that of the peculiar Type IIn 1998S. The emission from 2007pk falls below detection {approx}20 days after discovery in the UV and 50 days in the optical, showing no sign of the long duration emission seen in other Type IIn SNe. We examine the physical and spectral characteristics of 2007pk and compare its UV light curve and decay rate with other Type II SNe.

  1. Geotechnical Trainspotting: Early Observations From the New Seattle Liquefaction Array

    NASA Astrophysics Data System (ADS)

    Bodin, P.; Yelin, T.; Weaver, C. S.; Steidl, J. H.; Steller, R. A.; Gomberg, J. S.

    2012-12-01

    The Seattle Liquefaction Array (SLA) is a geotechnical monitoring array established by the US Geological Survey earlier this year in industrialized Seattle, Washington. Funding for the array was provided by the Advanced National Seismic System, at the behest of the Pacific Northwest Seismic Network's regional advisory committee. The SLA aims to further the understanding of earthquake-induced liquefaction, particularly the processes associated with repeatedly liquefied soils and the liquefaction of deeply buried deposits. The SLA occupies a site at which shaking-induced liquefaction was observed during earthquakes in 1949, 1965, and 2001. The SLA site is seismically noisy but important as it is similar to sites that host many structures in Seattle. The site is comprised chiefly by loose-to-dense interbedded coastal and river outwash sands. Instrumentation at the site includes four 3-component accelerometers at the surface and at depths of 5.4, 44.9, and 56.4 meters, a surface barometer, and six piezometers at depths of 6.9, 22.9, 28.9, 43.1, 46.9, and 51.9 meters. Emplacement depths were selected to sample a variety of liquefaction susceptibilities. Continuous data from all sensors are sampled at 200 samples per second, and are available from the IRIS DMC archive, with a buffer of data stored on site in the event of telemetry failure. To date, only a handful of earthquakes have produced shaking strong enough at the SLA to be observed within the high levels of background noise. However, the noise itself provides data useful to constrain the low-strain seismic and pressure response of the site. Notably, the array is within a few meters of a set of busy railroad tracks. Passing and parked trains expose the site to a broad bandwidth of deformations, including seismic frequencies, albeit with a source at the surface. Many times each day the site experiences both high levels of shaking, and step changes in the pressure field of a variety of amplitudes that may last from seconds to hours. The pore pressure response varies between sensors and can be used to elucidate the drained and undrained pressure response within the different strata. Spectral ratios of the ground motions from trains amongst the accelerometers confirm that the site is still responding linearly to these ground motions.

  2. [Early childhood psychosis versus early childhood autism? Differential diagnosis based on one week observation in an inpatient setting].

    PubMed

    Niederhofer, H; Kucan, S; Hackenberg, B; Huber, M; Gasteiger, W

    2002-02-01

    We report on the case of a 4-year old child suffering for the past six months from a lingering psychotic development. Several months of outpatient observation did not permit a clear differential diagnosis of either childhood autism or an early psychosis. During a one-week inpatient stay at our hospital recurring productive-psychotic episodes were observed that finally led to the exclusion of the diagnosis of "childhood autism" (ICD-10 F 84.0 (Dilling et al., 1993)) and to the diagnosis of "other disintegrative childhood disorder" (ICD-10: F 84.3 (Dilling et al., 1993)). PMID:11876084

  3. Dynamic modelling of spur gear pair and application of empirical mode decomposition-based statistical analysis for early detection of localized tooth defect

    NASA Astrophysics Data System (ADS)

    Parey, A.; El Badaoui, M.; Guillet, F.; Tandon, N.

    2006-06-01

    Gears are one of the most common and important machine components in many advanced machines. An improved understanding of vibration signal is required for the early detection of incipient gear failure to achieve high reliability. This paper mainly consists of two parts: in the first part, a 6-degree-of-freedom gear dynamic model including localized tooth defect has been developed. The model consists of a spur gear pair, two shafts, two inertias representing load and prime mover and bearings. The model incorporates the effects of time-varying mesh stiffness and damping, backlash, excitation due to gear errors and profile modifications. The second part consists of signal processing of simulated and experimental signals. Empirical mode decomposition (EMD) is a method of breaking down a signal without leaving a time domain. The process is useful for analysing non-stationary and nonlinear signals. EMD decomposes a signal into some individual, nearly monocomponent signals, named as intrinsic mode function (IMF). Crest factor and kurtosis have been calculated of these IMFs. EMD pre-processed kurtosis and crest factor give early detection of pitting as compared to raw signal.

  4. A Validation of the Early Childhood Classroom Observation Measure in Finnish and Estonian Kindergartens

    Microsoft Academic Search

    Marja-Kristiina Lerkkanen; Eve Kikas; Eija Pakarinen; Kaili Trossmann; Anna-Maija Poikkeus; Helena Rasku-Puttonen; Martti Siekkinen; Jari-Erik Nurmi

    2012-01-01

    Research Findings: The aim of the study was to examine the applicability and psychometric properties of the Early Childhood Classroom Observation Measure (ECCOM; D. J. Stipek & P. Byler, 2005) outside the United States. The ECCOM was used to observe 83 kindergarten teachers (49 in Finland and 34 in Estonia) in classroom situations. Self-ratings were obtained of teachers’ teaching practices,

  5. Lightning Sensing from Space: Early Observations to the Geostationary Lightning Mapper (Invited)

    Microsoft Academic Search

    H. Christian

    2010-01-01

    Lightning was serendipitously detected by some of the earliest space-based sensors. Small instruments of opportunity such as the Piggy Back Experiment followed these early observations. In 1980, NASA began a serious study on the possibility for observing lightning from geostationary orbit. An U-2 aircraft was instrumented with optical and electric field sensors and flown over the tops of thunderstorms. This

  6. A Validation of the Early Childhood Classroom Observation Measure in Finnish and Estonian Kindergartens

    ERIC Educational Resources Information Center

    Lerkkanen, Marja-Kristiina; Kikas, Eve; Pakarinen, Eija; Trossmann, Kaili; Poikkeus, Anna-Maija; Rasku-Puttonen, Helena; Siekkinen, Martti; Nurmi, Jari-Erik

    2012-01-01

    Research Findings: The aim of the study was to examine the applicability and psychometric properties of the Early Childhood Classroom Observation Measure (ECCOM; D. J. Stipek & P. Byler, 2005) outside the United States. The ECCOM was used to observe 83 kindergarten teachers (49 in Finland and 34 in Estonia) in classroom situations. Self-ratings…

  7. Observations of Glide and Decomposition of a<101> Dislocations at High Temperatures in Ni-Al Single Crystals Deformed along the Hard Orientation

    NASA Technical Reports Server (NTRS)

    Srinivasan, R.; Daw, M. S.; Noebe, R. D.; Mills, M. J.

    2003-01-01

    Ni-44at.% Al and Ni-50at.% single crystals were tested in compression in the hard (001) orientations. The dislocation processes and deformation behavior were studied as a function of temperature, strain and strain rate. A slip transition in NiAl occurs from alpha(111) slip to non-alphaaaaaaaaaaa9111) slip at intermediate temperatures. In Ni-50at.% Al single crystal, only alpha(010) dislocations are observed above the slip transition temperature. In contrast, alpha(101)(101) glide has been observed to control deformation beyond the slip transition temperature in Ni-44at.%Al. alpha(101) dislocations are observed primarily along both (111) directions in the glide plane. High-resolution transmission electron microscopy observations show that the core of the alpha(101) dislocations along these directions is decomposed into two alpha(010) dislocations, separated by a distance of approximately 2nm. The temperature window of stability for these alpha(101) dislocations depends upon the strain rate. At a strain rate of 1.4 x 10(exp -4)/s, lpha(101) dislocations are observed between 800 and 1000K. Complete decomposition of a alpha(101) dislocations into alpha(010) dislocations occurs beyond 1000K, leading to alpha(010) climb as the deformation mode at higher temperature. At lower strain rates, decomposition of a alpha(101) dislocations has been observed to occur along the edge orientation at temperatures below 1000K. Embedded-atom method calculations and experimental results indicate that alpha(101) dislocation have a large Peieris stress at low temperature. Based on the present microstructural observations and a survey of the literature with respect to vacancy content and diffusion in NiAl, a model is proposed for alpha(101)(101) glide in Ni-44at.%Al, and for the observed yield strength versus temperature behavior of Ni-Al alloys at intermediate and high temperatures.

  8. Exponential and non-exponential relaxation and early state of spinodal decomposition in polymer blends by SANS

    Microsoft Academic Search

    D. Schwahn; S. Janßen; T. Springer

    With neutron small-angle scattering it was found, for two different polymer blends, that the time-dependent structure factor\\u000a S(Q, t) relaxes exponentially or also non-exponentially after a temperature step has been applied. The classical Cahn-Hilliard-Cook\\u000a theory predicts an exponential time behaviour of S(Q, t). The observed deviations may be due to the correlation of the order parameter with internal motions of

  9. LU Decomposition

    NSDL National Science Digital Library

    Fitchett, Stephanie

    Created by Stephanie Fitchett and David Smith for the Connected Curriculum Project, the purpose of this module is to examine LU decompositions of matrices and to see how an LU decomposition can improve computational efficiency in solving matrix equations. This is part of a larger collection of learning modules hosted by Duke University.

  10. Observing the Cosmic Microwave Background Radiation: A Unique Window on the Early Universe

    NASA Technical Reports Server (NTRS)

    Hinshaw, Gary; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics,of the early universe. Within the framework of inflationary dark matter models observations of the anisotropy on sub-degree angular scales will reveal the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of approx. 1100. The validity of inflationary models will be tested and, if agreement is found, accurate values for most of the key cosmological parameters will result. If disagreement is found, we will need to rethink our basic ideas about the physics of the early universe. I will present an overview of the physical processes at work in forming the anisotropy and discuss what we have already learned from current observations. I will conclude with a brief overview of the recently launched Microwave Anisotropy Probe (MAP) mission which will observe the anisotropy over the full sky with 0.21 degree angular resolution. At the time of this meeting, MAP will have just arrived at the L2 Lagrange point, marking the start of its observing campaign. The MAP hardware is being produced by Goddard in partnership with Princeton University.

  11. Early GRB Optical and Infrared Afterglow Observations with the 2-m Robotic Liverpool Telescope

    E-print Network

    A. Gomboc; C. G. Mundell; C. Guidorzi; A. Monfardini; C. J. Mottram; R. Priddey; R. J. Smith; S. Pak; I. A. Steele; N. Tanvir; D. Carter; S. N. Fraser; M. F. Bode; A. M. Newsam; M. Hughes

    2005-05-03

    We present the first optical observations of a Gamma Ray Burst (GRB) afterglow using the 2-m robotic Liverpool Telescope (LT), which is owned and operated by Liverpool John Moores University and situated on La Palma. We briefly discuss the capabilities of LT and its suitability for rapid follow-up observations of early optical and infrared GRB light curves. In particular, the combination of aperture, site, instrumentation and rapid response (robotic over-ride mode aided by telescope's rapid slew and fully-opening enclosure) makes the LT ideal for investigating the nature of short bursts, optically-dark bursts, and GRB blast-wave physics in general. We briefly describe the LT's key position in the RoboNet-1.0 network of robotic telescopes. We present the LT observations of GRB041006 and use its gamma-ray properties to predict the time of the break in optical light curve, a prediction consistent with the observations.

  12. Climate model simulations of the observed early-2000s hiatus of global warming

    NASA Astrophysics Data System (ADS)

    Meehl, Gerald A.; Teng, Haiyan; Arblaster, Julie M.

    2014-10-01

    The slowdown in the rate of global warming in the early 2000s is not evident in the multi-model ensemble average of traditional climate change projection simulations. However, a number of individual ensemble members from that set of models successfully simulate the early-2000s hiatus when naturally-occurring climate variability involving the Interdecadal Pacific Oscillation (IPO) coincided, by chance, with the observed negative phase of the IPO that contributed to the early-2000s hiatus. If the recent methodology of initialized decadal climate prediction could have been applied in the mid-1990s using the Coupled Model Intercomparison Project Phase 5 multi-models, both the negative phase of the IPO in the early 2000s as well as the hiatus could have been simulated, with the multi-model average performing better than most of the individual models. The loss of predictive skill for six initial years before the mid-1990s points to the need for consistent hindcast skill to establish reliability of an operational decadal climate prediction system.

  13. Initialized Decadal Climate Predictions of the Observed Early-2000s Hiatus of Global Warming

    NASA Astrophysics Data System (ADS)

    Meehl, G. A.; Teng, H.; Arblaster, J.

    2014-12-01

    The slow-down in the rate of global warming in the early-2000s is not evident in the multi-model ensemble average of traditional climate change projection simulations. However, a number of individual ensemble members from that set of models successfully simulate the early-2000s hiatus when naturally-occurring climate variability involving the Interdecadal Pacific Oscillation (IPO) coincided, by chance, with the observed negative phase of the IPO that contributed to the early-2000s hiatus. If the recent methodology of initialized decadal climate prediction could have been applied in the mid-1990s using the CMIP5 multi-models, both the negative phase of the IPO in the early 2000s as well as the hiatus could have been simulated, with the multi-model average performing better than most of the individual models. The loss of predictive skill for six initial years prior to the mid-1990s points to the need for consistent hindcast skill to establish reliability of an operational decadal climate prediction system.

  14. Ozone decomposition.

    PubMed

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho; Zaikov, Gennadi E

    2014-06-01

    Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers). Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates. PMID:26109880

  15. Ozone decomposition

    PubMed Central

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho

    2014-01-01

    Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers). Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates.

  16. PROMPT Observations of the Early-Time Optical Afterglow of GRB 060607A

    E-print Network

    M. Nysewander; D. E. Reichart; J. A. Crain; A. Foster; J. Haislip; K. Ivarsen; A. Lacluyze; A. Trotter

    2008-10-24

    PROMPT (Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes) observed the early-time optical afterglow of GRB 060607A and obtained a densely sampled multiwavelength light curve that begins only tens of seconds after the GRB. Located at Cerro Tololo Inter-American Observatory in Chile, PROMPT is designed to observe the afterglows of gamma-ray bursts using multiple automated 0.4-m telescopes that image simultaneously in many filters when the afterglow is bright and may be highly variable. The data span the interval from 44 seconds after the GRB trigger to 3.3 hours in the Bgri filters. We observe an initial peak in the light curve at approximately three minutes, followed by rebrightenings peaking around 40 minutes and again at 66 minutes. Although our data overlap with the early Swift gamma-ray and x-ray light curves, we do not see a correlation between the optical and high-energy flares. We do not find evidence for spectral evolution throughout the observations. We model the variations in the light curves and find that the most likely cause of the rebrightening episodes is a refreshment of the forward shock preceded by a rapidly fading reverse shock component, although other explanations are plausible.

  17. [Observations of play and verbal behavior of boys with fragile X syndrome in early childhood].

    PubMed

    Sarimski, K

    1999-08-01

    Reports on development and behaviour in boys with fragile-X syndrome support the idea of a characteristic behavioural phenotype in this special population. Preliminary results are presented for 10 boys with fragile-X syndrome in early childhood. Severe mental handicaps and communicative abnormalities are observed less frequently than was expected on the basis of results reported for school-age children or adults. Boys with fragile-X syndrome show goal-directed and cooperative play behaviours in a Montessori play session, but less persistence and organisation than children with normal development or a mental handicap of heterogeneous origin. Results confirmed these behavioural differences as characteristic aspects of a "behavioural phenotype" in children who already in early childhood have fragile-X syndrome. PMID:10478436

  18. ``Early/slow'' events: A new category of VLF perturbations observed in relation with sprites

    NASA Astrophysics Data System (ADS)

    Haldoupis, C.; Steiner, R. J.; Mika, Á.; Shalimov, S.; Marshall, R. A.; Inan, U. S.; BöSinger, T.; Neubert, T.

    2006-11-01

    Analysis of subionospheric VLF transmissions, observed in relation with sprites, has led to the identification of a new category of VLF perturbations caused by the direct effects of tropospheric lightning on the overlying lower ionosphere. They constitute a large subset of the so-called "early/fast" events where now the term "fast," which implies rapid onset durations less than ˜20 ms, does not apply. In contrast with early/fast, the perturbations have a gradual growth and thus "slow" onset durations ranging from about 0.5 to 2.5 s; thus these events are labeled herein as "early/slow." They are indicative of a new physical process at work which, following a sprite-causative cloud-to-ground discharge, leads to a gradual buildup of conductivity changes in the lower ionosphere which must be responsible for the long onset durations of the observed perturbations. Analysis of broadband VLF sferic recordings, made with a two-channel receiver near the sprite producing storms, shows that the growth phase of an early/slow event coincides with the occurrence of complex and dynamic lightning action. This is composed of a few sequential cloud-to-ground lightning strokes and clusters (bursts) of sferics which are attributable to intracloud lightning. We postulate that the long onset durations are due to secondary ionization buildup in the upper D region below the nighttime VLF reflection heights, caused mainly by the impact on sprite-produced electrons of sequential electromagnetic pulses radiated upward from horizontal in-cloud discharges.

  19. Decomposition techniques

    USGS Publications Warehouse

    Chao, T.T.; Sanzolone, R.F.

    1992-01-01

    Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials makes it necessary to choose the sample decomposition technique that is compatible with the specific objective of the analysis. When selecting a decomposition technique, consideration should be given to the chemical and mineralogical characteristics of the sample, elements to be determined, precision and accuracy requirements, sample throughput, technical capability of personnel, and time constraints. This paper addresses these concerns and discusses the attributes and limitations of many techniques of sample decomposition along with examples of their application to geochemical analysis. The chemical properties of reagents as to their function as decomposition agents are also reviewed. The section on acid dissolution techniques addresses the various inorganic acids that are used individually or in combination in both open and closed systems. Fluxes used in sample fusion are discussed. The promising microwave-oven technology and the emerging field of automation are also examined. A section on applications highlights the use of decomposition techniques for the determination of Au, platinum group elements (PGEs), Hg, U, hydride-forming elements, rare earth elements (REEs), and multi-elements in geological materials. Partial dissolution techniques used for geochemical exploration which have been treated in detail elsewhere are not discussed here; nor are fire-assaying for noble metals and decomposition techniques for X-ray fluorescence or nuclear methods be discussed. ?? 1992.

  20. Photometric Analysis of the PAIRITEL Infrared Observations of Early Time Gamma Ray Burst Afterglows

    NASA Astrophysics Data System (ADS)

    Christian, Pierre; Morgan, A. N.; Bloom, J. S.; Klein, C. R.

    2012-01-01

    Since continuous operations began in 2004, the Peters Automated Infrared Imaging Telescope (PAIRITEL) has autonomously observed over 150 Swift GRBs within 24 hours of the trigger, including 16 in under 4 minutes of the trigger. Using improved pipelines, we have systematically re-reduced and photometered all observed events under 30 minutes of the trigger (20 bursts), yielding a homogenous sample of early-time JHKs lightcurves. Of the 20 bursts in our sample, 15 events have full-color light curves. Of the remaining bursts, 2 events are detected in at least one band and upper limits of the afterglow magnitude were obtained for the remainder of the set. We present an analysis of the results, showing IR magnitude/color distributions at fixed observer rest frame times since the trigger.

  1. Observation of x-ray resonant Raman scattering: The early days

    SciTech Connect

    Sparks, C.J.

    1995-12-31

    My early observation of Raman scattering came as a serendipitous by-product of our efforts to achieve the best possible signal for x-ray fluorescent analysis. We were also investigating the x-ray spectrum produced by a monochromatic x-ray beam striking metal targets which might contribute to the inelastic background. This background could contaminate the very weak diffusively distributed elastically scattered radiation associated with defects in the perfect periodicity of crystals. Energy analysis of the x-ray spectra created by monochromatic Cu K{sub {alpha}} and Mo K{sub {alpha}} radiation impinging on highly pure metal targets showed an inelastically scattered intensity related to the energy difference between the exciting radiation and the nearest bound state. Confirmation of these observations and availability of synchrotron radiation has led to wide application of this new x-ray spectroscopy in atomic physics including its use as a probe of the unoccupied density of states.

  2. Early observations of comet Churyumov-Gerasimenko with the Rosetta MIRO submillimeter instrument

    NASA Astrophysics Data System (ADS)

    Gulkis, S.; Allen, M.; Von Allmen, P.; Beaudin, G.; Biver, N.; Bockelee-Morvan, D.; Choukroun, M.; Crovisier, J.; Encrenaz, P.; Encrenaz, T.; Frerking, M.; Hartogh, P.; Hofstadter, M.; Ip, W.; Janssen, M.; Jarchow, C.; Kamp, L.; Keihm, S.; Lee, S.; Lellouch, E.; Leyrat, C.; Rezac, L.; Schloerb, F.; Spilker, T.

    2014-07-01

    The Rosetta spacecraft is now approaching comet 67P/Churyumov- Gerasimenko, preparing to enter orbit in August 2014 and place a lander on the nucleus in November. The Microwave Instrument on the Rosetta Orbiter (MIRO) is designed to study the coma and immediate sub-surface of the nucleus. It has two broad-band continuum channels (center frequencies near 560 and 190 GHz, or wavelengths near 0.5 and 1.6 mm) which probe the thermal and dielectric properties of the upper ˜ centimeters of the nucleus. It also contains a high spectral resolution (44 kHz) spectrometer working in the submillimeter band to study the abundance, velocity, temperature, and three-dimensional structure of select species in the coma. Those species are H_2O, H_2^{17}O, H_2^{18}O, CO, NH_3, and CH_3OH. Scientific observations with the MIRO instrument were started in early May 2014, when the comet-spacecraft separation distance was 1.8 million kilometers. Initial observations were designed to search for H_2O and CO in the coma and for thermal emission from the nucleus. Early detection of the coma is expected only if gas production rates are relatively high (˜ 1×10^{26} water molecules/second at a heliocentric distance near 4 au). We will present the results of our initial measurements, describe the detailed mapping of the coma and nucleus we plan to do over the coming months.

  3. Observations and modeling of the early acceleration phase of erupting filaments involved in coronal mass ejections

    E-print Network

    C. J. Schrijver; C. Elmore; B. Kliem; T. Toeroek; A. M. Title

    2007-10-08

    We examine the early phases of two near-limb filament destabilization involved in coronal mass ejections on 16 June and 27 July 2005, using high-resolution, high-cadence observations made with the Transition Region and Coronal Explorer (TRACE), complemented by coronagraphic observations by Mauna Loa and the SOlar and Heliospheric Observatory (SOHO). The filaments' heights above the solar limb in their rapid-acceleration phases are best characterized by a height dependence h(t) ~ t^m with m near, or slightly above, 3 for both events. Such profiles are incompatible with published results for breakout, MHD-instability, and catastrophe models. We show numerical simulations of the torus instability that approximate this height evolution in case a substantial initial velocity perturbation is applied to the developing instability. We argue that the sensitivity of magnetic instabilities to initial and boundary conditions requires higher fidelity modeling of all proposed mechanisms if observations of rise profiles are to be used to differentiate between them. The observations show no significant delays between the motions of the filament and of overlying loops: the filaments seem to move as part of the overall coronal field until several minutes after the onset of the rapid-acceleration phase.

  4. Early Observations with the Rosetta/MIRO Instrument at comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Gulkis, Samuel

    2015-04-01

    The MIRO (Microwave Instrument on the Rosetta Orbiter) is a dual frequency (560 GHz and 190 GHz) heterodyne instrument consisting of two broadband channels (one in each frequency band) for continuum measurements, and a very high spectral resolution (44 kHz, 4096 channels) spectrometer interfaced with the submillimeter radiometer. Broad scientific objectives are to understand heat transport and ice sublimation in comets as interrelated processes reflecting properties acquired at time of formation and subsequent evolution and to understand important processes in the coma. The spectroscopic receiver is fixed tuned to measure simultaneously 8 molecular transitions of water, carbon monoxide, ammonia, and methanol. The continuum channels probe the nucleus sub-surface temperatures; the spectrometer channels are sensitive to gas abundance, velocity, and temperature. This paper will present an overview of the MIRO instrument, status of observations, and early results. Early results include detection and monitoring of water vapor in the coma, measurements of water gas production rates and their temporal and spatial variability, and measurements of subsurface temperatures and temperature gradients in the nucleus at depths of a few centimeters. The authors acknowledge funding support from NASA, CNES and CNRS/INSU, National Central University, and SNSB (Sweden). A part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. We thank the operational support teams from the ESA Rosetta Mission.

  5. New insights in the capability of climate models to simulate the impact of LUC based on temperature decomposition of paired site observations

    NASA Astrophysics Data System (ADS)

    Vanden Broucke, Sam; Luyssaert, Sebastiaan; Davin, Edouard L.; Janssens, Ivan; Lipzig, Nicole

    2015-06-01

    In this study, we present a new methodology for evaluating the biogeophysical impact of land use change (LUC) in regional climate models. For this, we use observational data from paired eddy covariance flux towers in Europe, representing a LUC from forest to open land (deforestation). Two model simulations with the regional climate model COSMO-CLM2 (The Consortium for Small-Scale Modelling model in climate mode COSMO-CLM coupled to the Community Land Model CLM) are performed which differ only in prescribed land use for site pair locations. The model is evaluated by comparing the observed and simulated difference in surface temperature (Ts) between open land and forests. Next, we identify the biogeophysical mechanisms responsible for Ts differences by applying a decomposition method to both observations and model simulations. This allows us to determine which LUC-related mechanisms were well represented in COSMO-CLM2, and which were not. Results from observations show that deforestation leads to a significant cooling at night, which is severely underestimated by COSMO-CLM2. It appears that the model is missing one crucial impact of deforestation on the nighttime surface energy budget: a reduction in downwelling longwave radiation. Results are better for daytime, as the model is able to simulate the increase in albedo and associated surface cooling following deforestation reasonably well. Also well simulated, albeit underestimated slightly, is the decrease in sensible heat flux caused by reduced surface roughness. Overall, these results stress the importance of differentiating between daytime and nighttime climate when discussing the effect of LUC on climate. Finally, we believe that they provide new insights supporting a wider application of the methodology (to other regional climate models).

  6. Mars Reconnaissance Orbiter: An Overview of Early Results and Plans for Further Observation

    NASA Astrophysics Data System (ADS)

    Zurek, R. W.; Graf, J. E.; Smrekar, S.; Keating, G. M.; Malin, M.; McCleese, D. J.; McEwen, A. S.; Murchie, S. L.; Phillips, R. J.; Seu, R.; Zuber, M. T.

    2006-12-01

    Launched August 12, 2005, the Mars Reconnaissance Orbiter (MRO) entered Mars orbit on March 10, 2006 and finished its aerobraking phase on August 30, 2006. Accelerometer measurements taken during each of nearly 420 aeropasses provided data collection for the first of the eight scientific investigations selected by NASA for MRO. Prior to solar conjunction, MRO deployed the SHARAD radar antenna and opened the cover to the CRISM imaging spectrometer telescope, thereby completing all instrument deployment activities. All instruments were powered on and a series of observations were taken over a week-long check-out period. During solar conjunction itself (in October), the two atmospheric monitoring instruments, MARCI and MCS, continued to observe. MRO then began its nominal Primary Science Phase on November 8. At the time of the AGU meeting, MRO will have completed the first 2 of the 55 two-week planning cycles that will span slightly more than one Mars year of primary science observations. This presentation will give an overview of early results from MRO, with more detailed presentations to follow for selected investigations, and provide a preview of upcoming activities. NASA's Jet Propulsion Laboratory (JPL), California Institute of Technology, manages the Mars Reconnaissance Orbiter for the NASA Science Mission Directorate; the work reported here was done as part of the MRO Project under contract with the National Aeronautics and Space Administration.

  7. Prelexical Decomposition of Compound and Pseudocompound Words

    E-print Network

    Diener, Un So Park

    2007-12-12

    Previous studies on morphologically complex words suggest early decomposition in the visual word process. In that case, morpheme-like constituents of pseudocompound words (e.g. mushroom) should also be decomposed during ...

  8. Early Results from the First Year of Observations by the Atacama B-mode Search (ABS)

    NASA Astrophysics Data System (ADS)

    Simon, Sara M.; ABS Collaboration

    2013-06-01

    The Atacama B-mode Search (ABS) instrument, which began observation in February of 2012, is a crossed-Dragone telescope located at an elevation of 5100 m in the Atacama Desert in Chile. The primary scientific goal of ABS is to measure the B-mode polarization spectrum of the Cosmic Microwave Background (CMB) from multipole moments of about l=50 to l=500, a range that includes the primordial B-mode peak. Unlike most current polarization experiments, ABS features a cryogenic telescope and a warm half-wave plate used to modulate the polarization of the incoming light. The ABS focal plane array consists of 240 pixels designed for observation at 150 GHz by the TRUCE collaboration. Each pixel has its own individual, single-moded feedhorn and contains two transition-edge sensor (TES) bolometers sensitive to orthogonal polarizations. The detectors are read out using time domain multiplexing so that the thermal loading of the readout electronics does not heat the focal plane. I will present early results from the first year of ABS data.

  9. Thermal decomposition of developing enamel

    Microsoft Academic Search

    I. Mayer; S. Schneider; M. Sydney-Zax; D. Deutsch

    1990-01-01

    Summary  The decomposition of forming, maturing, and mature enamel was studied between room temperature and 1,000°C by powder X-ray\\u000a diffraction and infrared absorption methods. In mature dental enamel, carbonate decomposition proceeds relatively fast until\\u000a 500°C and at a slower rate beyond it. In forming and maturing enamel, decomposition is faster and is completed around 800°C.\\u000a The formation of ?-Ca3(PO4)2 is observed

  10. NIRS0S: Observations of early-type galaxy secular evolution spanning the Sa/S0/disky-E boundaries

    NASA Astrophysics Data System (ADS)

    Laurikainen, Eija; Salo, Heikki; Buta, Ronald; Knapen, Johan

    2015-03-01

    NIRS0S (Near-IR S0 galaxy Survey), is a K-band survey of ~ 200 early-type disk galaxies, mainly S0s, 2-3 mag deeper than the 2Micron All Sky Survey. In depth morphological analysis was done, in which multi-component structural decompositions played an important role. Possible implications to internal dynamical galaxy evolution were discussed. S0s were suggested to be former spirals in which star formation has ceased, forming a parallel sequence with spirals (see Fig. 1). If that evolution is faster among the brighter galaxies, the observed magnitude difference between the barred and non-barred S0s could be understood. Bars are suggested to play a critical role in such evolution. For example, the inner lenses in the bright non-barred S0s can be explained as former barlenses (inner parts of bars), in which the elongated bar component has dissolved. We suggest that the last destructive merger event happened at a fairly large redshift.

  11. An overview of the Cosmic Background Explorer (COBE) and its observations - New sky maps of the early universe

    NASA Technical Reports Server (NTRS)

    Smoot, George F.

    1992-01-01

    This paper discusses the three instruments aboard NASA's Cosmic Background Explorer (COBE) satellite and presents early results obtained from the first six months of observations. The three instruments (FIRAS, DMR, and DIRBE) have operated well and produced significant new results. The FIRAS measurement of the CMB spectrum supports the standard Big Bang model. The maps made from the DMR instrument measurements show a spatially smooth early universe. The maps of galactic and zodiacal emission produced by the DIRBE instrument are needed to identify the foreground emissions from extragalactic and thus to interpret its and the other COBE results in terms of events in the early universe.

  12. Early results on 67P/Churyumov-Gerasimenko observed by Rosetta/OSIRIS

    NASA Astrophysics Data System (ADS)

    Sierks, H.; Tubiana, C.; Snodgrass, C.; Agarwal, J.; Güttler, C.; Oklay, N.; Vincent, J.; Küppers, M.; Barbieri, C.; Lamy, P.; Rickman, H.; Rodrigo, R.; Koschny, D.; Hviid, S.; Mottola, S.; Osiris Team

    2014-07-01

    67P/Churyumov-Gerasimenko (67P) is the target comet of the ESA Rosetta mission. Launched in 2004, the Rosetta spacecraft woke up on the 20th of January 2014. After 36 months of deep space hibernation, Rosetta is now traveling to rendezvous with the comet at 4.1 au from the Sun, and it will follow 67P along its orbit, investigating how the comet changes and evolves while approaching the Sun. The Optical, Spectroscopic, and Infrared Remote Imaging System OSIRIS (Keller et al., 2007) is the scientific imaging system onboard Rosetta. It comprises the Narrow Angle Camera (NAC) with wavelength range 250--1000 nm and the Wide Angle Camera (WAC) with wavelength range 240--720 nm. The NAC (FOV = 2.20×2.22 deg) is a system with high spatial resolution that allows an initial detection of the nucleus, studies its structure and rotation from relatively great distances, investigates the mineralogy of the surface, and studies the dust ejection processes. The WAC has much lower spatial resolution but, accordingly, a much wider field of view (about 11.35×12.11 deg). This allows observations of the 3-dimensional flow field of dust and gas near the nucleus and, in addition, provides a synoptic view of the whole nucleus. In summary, the WAC would provide long-term monitoring of the entire nucleus from close distances, while the NAC studies the details. The two camera units have been designed as a complementary pair, which, on one hand, addresses the study of the nucleus surface, and on the other hand, investigates the dynamics of the sublimation process. After commissioning in March 2014, OSIRIS took first images of comet 67P and its dust environment. Ground-based observations performed in 2007/08 when 67P was in the same orbital arc as it will be in March/April 2014, show that the comet was already active at 4.3 au inbound and that its behavior was repetitive during the last three apparitions (Snodgrass et al. 2013). We therefore expect to detect early comet activity by OSIRIS in March/April 2014. At this time, Rosetta will be at about 4 million kilometers from the comet and 67P will still be unresolved. We present results about the early cometary activity based on OSIRIS images. Orange-filter images (central wavelength 649.2 nm) will be used to determine the dust environment of 67P, since this wavelength range is quite free from gas emission lines. Moreover, a series of lightcurves will be taken to compare with the existing ones and look for possible changes in the rotational period due to its last perihelion passage.

  13. Hubble's Early Release Observations Student Pilot Project: Implementing Formal and Informal Collaborations

    NASA Astrophysics Data System (ADS)

    Eisenhamer, B.; Ryer, H.; McCallister, D.

    2012-08-01

    The Hubble Space Telescope's Early Release Observations (EROs) were revealed to the public on September 9, 2009, and K-12 students and educators in five states across the country were able to join the celebration. To date, students and educators in Maryland, Ohio, New York, California, and Florida have participated in the Hubble Space Telescope's ERO Pilot Project. This is an interdisciplinary project created by the Space Telecope Science Institute's (STScI) Office of Public Outreach in which students use skills from subject areas such as language arts, science, art, and technology to research the four ERO objects and create compositions. In recognition of their participation, the students' compositions are displayed at host institutions in each state (a museum, science center, school, planetarium or library) during a special public event for participating students, their families, and teachers. As part of its evaluation program, STScI's Office of Public Outreach has been conducting an evaluation of the project to determine the viability and potential of conducting large-scale, formal/informal collaborative projects in the future and to share lessons learned. Lessons learned will be applied to a new interdisciplinary project, the James Webb Space Telescope Student Innovation Project.

  14. Constraint on the early Universe by relic gravitational waves: From pulsar timing observations

    SciTech Connect

    Zhao Wen [Department of Physics, Zhejiang University of Technology, Hangzhou 310014 (China) and Niels Bohr Institute, Copenhagen University, Blegdamsvej 17, Copenhagen DK-2100 (Denmark)

    2011-05-15

    Recent pulsar timing observations by the Parkers Pulsar Timing Array (PPTA) and European Pulsar Timing Array (EPTA) teams obtained the constraint on the relic gravitational waves at the frequency f{sub *}=1/yr, which provides the opportunity to constrain H{sub *}, the Hubble parameter, when these waves crossed the horizon during inflation. In this paper, we investigate this constraint by considering the general scenario for the early Universe: we assume that the effective (average) equation-of-state w before the big bang nucleosynthesis stage is a free parameter. In the standard hot big-bang scenario with w=1/3, we find that the current PPTA result follows a bound H{sub *{<=}}1.15x10{sup -1}m{sub Pl}, and the EPTA result follows H{sub *{<=}}6.92x10{sup -2}m{sub Pl}. We also find that these bounds become much tighter in the nonstandard scenarios with w>1/3. When w=1, the bounds become H{sub *{<=}}5.89x10{sup -3}m{sub Pl} for the current PPTA and H{sub *{<=}}3.39x10{sup -3}m{sub Pl} for the current EPTA. In contrast, in the nonstandard scenario with w=0, the bound becomes H{sub *{<=}}7.76m{sub Pl} for the current PPTA.

  15. Early Observations with the Rosetta Langmuir Probe Instrument at the Target Comet

    NASA Astrophysics Data System (ADS)

    Eriksson, A. I.; Edberg, N. J. T.; Gill, R.; Johansson, F.; Odelstad, E.; Wahlund, J. E.; Vigren, E.; Karlsson, T.; Lindqvist, P. A.; Jarvinen, R.; Lybekk, B.; Miloch, W.; Pedersen, A.; Lebreton, J. P.; Carr, C.; Cupido, E.

    2014-12-01

    Rosetta provides an unprecedented opportunity to follow the evolution of the plasma environment close to a comet as activity grows and recedes from 4 AU to perihelion and out again. Like the rest of the Rosetta Plasma Consortium (RPC), the Langmuir probe instrument (RPC-LAP) has been operating from early summer 2014 to cover also the approach of Rosetta toward comet 67P/Churyumov-Gerasimenko. The instrument uses two spherical probes mounted on short (few meters) solid booms protruding from the spacecraft body. The probes can be used as classical Langmuir probes, as electric field probes with bias current and for wave observations up to 8 kHz. In the low density solar wind, probe bias sweeps are dominated by spacecraft photoelectrons, but plasma density variations can still be accessed through the spacecraft potential. As the density of the comet plasma increases with growing comet activity, direct plasma measurements become possible. We present initial data and first results on the comet plasma environment.

  16. Characteristics of long recovery early VLF events observed by the North African AWESOME Network

    NASA Astrophysics Data System (ADS)

    Naitamor, S.; Cohen, M. B.; Cotts, B. R. T.; Ghalila, H.; Alabdoadaim, M. A.; Graf, K.

    2013-08-01

    Lightning strokes are capable of initiating disturbances in the lower ionosphere, whose recoveries persist for many minutes. These events are remotely sensed via monitoring subionospherically propagating very low frequency (VLF) transmitter signals, which are perturbed as they pass through the region above the lightning stroke. In this paper we describe the properties and characteristics of the early VLF signal perturbations, which exhibit long recovery times using subionospheric VLF transmitter data from three identical receivers located at Algiers (Algeria), Tunis (Tunisia), and Sebha (Libya). The results indicate that the observation of long recovery events depends strongly on the modal structure of the signal electromagnetic field and the distance from the disturbed region and the receiver or transmitter locations. Comparison of simultaneously collected data at the three sites indicates that the role of the causative lightning stroke properties (e.g., peak current and polarity), or that of transient luminous events may be much less important. The dominant parameter which determines the duration of the recovery time and amplitude appears to be the modal structure of the subionospheric VLF probe signal at the ionospheric disturbance, where scattering occurs, and the subsequent modal structure that propagates to the receiver location.

  17. On the early onset of the NLC season 2013 as observed at ALOMAR

    NASA Astrophysics Data System (ADS)

    Fiedler, Jens; Baumgarten, Gerd; Berger, Uwe; Gabriel, Axel; Latteck, Ralph; Lübken, Franz-Josef

    2015-05-01

    On 21 May the ALOMAR RMR-lidar in Northern Norway detected the first noctilucent clouds (NLC) in 2013. This unusual early NLC onset was accompanied by ?6 K lower temperatures and higher water vapor mixing ratios at NLC altitudes from the end of April until the beginning of June. The zonal mean temperature and dynamic conditions in the Arctic middle atmosphere deviated in spring 2013 significantly from the mean conditions of the last 20 years. Furthermore the planetary wave activity in the high latitude stratosphere was enhanced from 20 April to beginning of May. The colder and wetter upper mesosphere in May 2013 is attributed to this unusual late planetary wave activity in the stratosphere, introducing a strong upwelling in the mesosphere, lower temperatures and an upward transport of water vapor, which finally resulted in earlier existence conditions for mesospheric ice particles. We regard this as a first evidence for intra-hemispheric coupling in the northern hemisphere extending from the stratosphere into the mesopause region. Yet it is unclear whether this is an unusual extreme event or an indicator for a change in the circulation due to the observed long-term cooling of the middle atmosphere.

  18. Fast Approximate Convex Decomposition 

    E-print Network

    Ghosh, Mukulika

    2012-10-19

    Approximate convex decomposition (ACD) is a technique that partitions an input object into "approximately convex" components. Decomposition into approximately convex pieces is both more efficient to compute than exact convex decomposition and can...

  19. Variable Deformation Rates at Sierra Negra Volcano: Geodetic Observations from 2008 to Early 2014

    NASA Astrophysics Data System (ADS)

    Meier, N. J.; La Femina, P. C.; Geirsson, H.; Ruiz, G.

    2014-12-01

    Sierra Negra is a basaltic shield volcano located at the southern end of Isabela Island, Galápagos Islands, Ecuador. The volcano, along with the rest of the Galápagos Islands, has formed by hotspot volcanism. The volcano has erupted twice over the last 35 years, producing VEI-3 eruptions in November 1979 and October 2005. Previous studies suggest that deformation is due to a flat-topped chamber or sill centered 1.9-2.2 km beneath the caldera (Amelung et al. 2000; Yun et al. 2006; Geist et al. 2007). Ten continuous Global Positioning System (cGPS) stations were installed within and on the rim of the caldera of Sierra Negra (i.e., sites GV01 - GV10) in 2002, 2006, and 2009 to track ongoing deformation. In addition, there is one cGPS site on the nearby (90 km) island of Santa Cruz (GLPS), where no recent volcanism has been observed. We analyzed the cGPS data for the period 2008 to 2014 using GIPSY-OASIS II and produced daily position time series for each site. We then estimated yearly velocities for each site assuming linear deformation. We subtract the velocity vector for site GLPS from all Sierra Negra cGPS sites to remove the motion of the Nazca plate. The resulting horizontal and vertical velocity fields indicate significant upward and outward displacement of the volcanic edifice, which we interpret as caused by the influx of new magma or magma chamber pressurization. There are significant yearly variations in both the direction and magnitude of station velocities. For the period covering 2008 to 2011 there is accelerating inflation. Maximum rates of deformation (mm/yr) are seen at GV07 in 2008 (87.02), GV09 in 2009 (161.18), and GV03 in 2010 (191.03). Inflation continues for the period 2011-2013, but at a slower rate. Maximum rates are seen at GV03 in 2011 (78.53) and GV06 in 2012 (22.44). The rate then increases again for the period covering mid-2013 through early 2014. Maximum rates are seen at GV06 in both 2013 (318.27) and early 2014 (308.53). The maximum vertical uplift rates (564.92) are seen at the sites closest to the center of the caldera, GV02 and GV04. A preliminary model for the influx of magma into the system during 2013 suggests 0.015 km3 and a source depth of 2.2 km.

  20. Observing the Cosmic Microwave Background Radiation: A Unique Window on the Early Universe

    Microsoft Academic Search

    Gary Hinshaw

    2001-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics of the early universe.

  1. Linear decomposition-based methodology for determining the relative importance of wind and non-wind phenomena on observed air quality

    NASA Astrophysics Data System (ADS)

    Wong, Kit Man

    Air pollution in Hong Kong (HK) is becoming more significant. Many people have expressed their concern about changes in air quality. The problems and concerns have been manifest, in recent years, in HK and the Pearl River Delta (PRD) region. Typically, it is believed that increased emissions should be blamed for causing air pollution in this region. However, the authorities explain that increased occurrence in calm/light wind conditions is also important in hindering dispersion of air pollutants. Understanding the real causes can benefit in setting the best control policies. The conflict between the "emission" and "wind pattern" viewpoints can be resolved if we can distinguish the respective contributions of wind changes (wind influence) and emission strengths (non-wind influence) on air quality. However, up to now, there has been no systematic way to determine the relative importance of these two main phenomena on air quality. Most current related research can only show they have an impact on air quality. Little has compared them quantitatively. This research first investigated whether the frequency of calm/light wind conditions is closely related to the concentration of pollutants. The plotted charts show high wind speed with low pollutant concentration and vice versa. Although the frequency distributions of wind speed in 2000 -- 2003 versus 2004 -- 2007 do show that there was a higher frequency of low wind speeds in the latter period, when pollution levels are compared during periods of similar wind speed, they are higher in the latter period than in the former. A linear decomposition-based methodology is proposed to distinguish the relative importance of these two main phenomena on air quality. Based on the hourly wind data (speed and direction) and pollutant concentration, the wind frequency and pollutant emission "roses" (circular frequency diagrams) are established. Hypothetical pollutant concentration can be calculated from these two roses. By comparing the hypothetical pollutant concentration with the actual measurement, the relative importance of these two main phenomena on average pollutant concentration in two periods can be determined respectively quantitatively. Last, the respirable suspended particulates (RSP), ozone (O3), nitrogen dioxide (NO2) and sulphur dioxide (SO2) in 2000 -- 2007 in HK were analyzed and two past air quality related controversial cases were also studied. It is shown that the non-wind influence on observed air quality in HK was more significant than the wind influence in annual-based comparison.

  2. A Different View on the Checkerboard? Alterations in Early and Late Visually Evoked EEG Potentials in Asperger Observers

    PubMed Central

    Kornmeier, Juergen; Wörner, Rike; Riedel, Andreas; Bach, Michael; Tebartz van Elst, Ludger

    2014-01-01

    Background Asperger Autism is a lifelong psychiatric condition with highly circumscribed interests and routines, problems in social cognition, verbal and nonverbal communication, and also perceptual abnormalities with sensory hypersensitivity. To objectify both lower-level visual and cognitive alterations we looked for differences in visual event-related potentials (EEG) between Asperger observers and matched controls while they observed simple checkerboard stimuli. Methods In a balanced oddball paradigm checkerboards of two checksizes (0.6° and 1.2°) were presented with different frequencies. Participants counted the occurrence times of the rare fine or rare coarse checkerboards in different experimental conditions. We focused on early visual ERP differences as a function of checkerboard size and the classical P3b ERP component as an indicator of cognitive processing. Results We found an early (100–200 ms after stimulus onset) occipital ERP effect of checkerboard size (dominant spatial frequency). This effect was weaker in the Asperger than in the control observers. Further a typical parietal/central oddball-P3b occurred at 500 ms with the rare checkerboards. The P3b showed a right-hemispheric lateralization, which was more prominent in Asperger than in control observers. Discussion The difference in the early occipital ERP effect between the two groups may be a physiological marker of differences in the processing of small visual details in Asperger observers compared to normal controls. The stronger lateralization of the P3b in Asperger observers may indicate a stronger involvement of the right-hemispheric network of bottom-up attention. The lateralization of the P3b signal might be a compensatory consequence of the compromised early checksize effect. Higher-level analytical information processing units may need to compensate for difficulties in low-level signal analysis. PMID:24632708

  3. Gestalt experiments and inductive observations Konrad Lorenz's early epistemological writings and the methods of classical ethology

    Microsoft Academic Search

    Ingo Brigandt

    During the 1940s Konrad Lorenz formulated his early epistemological views, focusing on the cognitive mechanisms induction and Gestalt perception. After the war he used this philosophical framework to defend the approach of classical ethology against other approaches to animal behavior. The present paper examines the relationship between Lorenz's ethological methodology and his philosophy of science and knowledge. The main aim

  4. Small-scale early aggregation of green tide macroalgae observed on the Subei Bank, Yellow Sea.

    PubMed

    Hu, Song; Yang, Hong; Zhang, Jianheng; Chen, Changsheng; He, Peimin

    2014-04-15

    Massive green algae blooms became an environmental disaster in the Yellow Sea from 2008 to 2013. Recent studies suggested that recurrences of early aggregates of macroalgae were found over the Subei Bank, a unique shallow radial sand ridge system off the Jiangsu coast, China. Yearly field surveys have been carried out over this bank during the past five years (2009-2013), with an aim at identifying and qualifying the physical-biological mechanism for the early aggregation of algae. Data synthesis showed that early aggregation of macroalgae usually occurred from April-May as small-scale patches either over the intertidal mudflat of the Subei Bank or along local isobaths in the northern coastal area north of the bank. Both hydrographic and current measurements were performed by tracking a narrow patchy area of floating macroalgae (nearly 4 km in length and 5-10 m in width) on April 26, 2013, and the results showed that the algae aggregation was mainly caused by tide-induced convergence. This convergence was produced by the local geometrically controlled interaction of tidal currents with mudflats, which is believed to be a key physical mechanism for the early development of algal blooms in addition to marine ecosystem responses and human aquaculture activities. PMID:24569106

  5. The 3-D effects in the long-term solar wind speed rise observed by Voyager 2 in early 1994

    Microsoft Academic Search

    V. J. Pizzo; K. I. Paularena; J. D. Richardson; A. J. Lazarus; J. W. Belcher

    1995-01-01

    In early 1994, Voyager 2 at 42-43 AU near heliolatitude 10 deg S observed over a period of approximately 100 days a remarkable sequence of quasi-recurrent stream fronts, wherein the background (ambient) speed rose steadily from approximately 450 to approximately 550 km\\/s while the mean period of the streams decreased from the usual 25 days down to approximately 20 days.

  6. Kinetics of spinodal decomposition in a critical polymer solution

    SciTech Connect

    Kubota, K.; Kuwahara, N. (Dept. of Biological and Chemical Engineering, Faculty of Technology, Gunma Univ., Kirya, Gunma 376 (Japan))

    1992-08-10

    This paper reports that spinodal decomposition in a critical mixture of polydimethylsiloxane and diethyl carbonate was investigated by a time-resolved light-scattering technique in the time region of the early to the intermediate stage of phase separation. The exponential growth of the scattered light intensity without changing the wave number of its peak was observed, in good agreement with the linearized theory of Cahn-Hillard. The quench depth dependences of the interdiffusion coefficient and of the wave number corresponding to the most dominant fluctuation show the three-dimensional Ising-model behavior indicating the validity of the symmetric law of critical-point universality.

  7. Thermocatalytic decomposition of vulcanized rubber

    E-print Network

    Qin, Feng

    2007-04-25

    . Temperatures between 400 �°C and 500 �°C range are required to drive off significant amounts of catalyst. Decomposition of the catalyst also occurred in the recovery process. Reports in the literature and our observations strongly suggest that the AlCl3...

  8. Early-time observations of gamma-ray burst error boxes with the Livermore optical transient imaging system

    NASA Astrophysics Data System (ADS)

    Williams, George Grant

    Approximately three times per day a bright flash of high energy radiation from the depths of the universe encounters the Earth. These gamma-ray bursts (GRBs) were discovered circa 1970 yet their origin remains a mystery. Traditional astronomical observations of GRBs are hindered by their transient nature. They have durations of only a few seconds and occur at random times from unpredictable directions. In recent years, precise GRB localizations and rapid coordinate dissemination have permitted sensitive follow-up observations. These observations resulted in the identification of long wavelength counterparts within distant galaxies. Despite the wealth of data now available the physical mechanism which produces these extremely energetic phenomena is still unknown. In the near future, simultaneous and early-time optical observations of GRBs will aid in constraining the theoretical models. The Livermore Optical Transient Imaging System (LOTIS) is an automated robotic wide field-of-view telescope dedicated to the search for prompt and early-time optical emission from GRBs. Since routine operations began in October 1996 LOTIS has responded to over 145 GRB triggers. LOTIS has not yet detected optical emission from a GRB but upper limits provided by the telescope constrain the theoretical emission mechanisms. Super-LOTIS, also a robotic wide field-of-view telescope, is 100 times more sensitive than LOTIS. Routine observations from Steward Observatory's Kitt Peak Station will begin in the immediate future. During engineering test runs Super-LOTIS obtained its first upper limit on the early-time optical afterglow of GRBs. An overview of the history and current state of GRBs is presented. Theoretical models are reviewed briefly. The LOTIS and Super-LOTIS hardware and operating procedures are discussed. A summary of the results from both LOTIS and Super-LOTIS and an interpretation of those results is presented. Plans for future studies with both systems are briefly stated.

  9. Decompositional equivalence: A fundamental symmetry from which quantum theory follows

    E-print Network

    Chris Fields

    2015-04-20

    Decompositional equivalence is the principle that there is no preferred decomposition of the universe into subsystems. It is shown here, by using simple thought experiments, that quantum theory follows from decompositional equivalence together with Landauer's principle. This demonstration raises within physics a question previously left to psychology: how do human - or any - observers agree about what constitutes a "system of interest"?

  10. Use of 13C NMR and ftir for elucidation of degradation pathways during natural litter decomposition and composting I. early stage leaf degradation

    USGS Publications Warehouse

    Wershaw, R.L.; Leenheer, J.A.; Kennedy, K.R.; Noyes, T.I.

    1996-01-01

    Oxidative degradation of plant tissue leads to the formation of natural dissolved organic carbon (DOC) and humus. Infrared (IR) and 13C nuclear magnetic resonance (NMR) spectrometry have been used to elucidate the chemical reactions of the early stages of degradation that give rise to DOC derived from litter and compost. The results of this study indicate that oxidation of the lignin components of plant tissue follows the sequence of O-demethylation, and hydroxylation followed by ring-fission, chain-shortening, and oxidative removal of substituents. Oxidative ring-fission leads to the formation of carboxylic acid groups on the cleaved ends of the rings and, in the process, transforms phenolic groups into aliphatic alcoholic groups. The carbohydrate components are broken down into aliphatic hydroxy acids and aliphatic alcohols.

  11. Spinodal Decomposition Mechanism of ?' Precipitation in a Single Crystal Ni-Based Superalloy

    NASA Astrophysics Data System (ADS)

    Tan, X. P.; Mangelinck, D.; Perrin-Pellegrino, C.; Rougier, L.; Gandin, Ch.-A.; Jacot, A.; Ponsen, D.; Jaquet, V.

    2014-10-01

    The precipitation of ?' phase in a commercial single crystal Ni-based superalloy with different cooling rates has been investigated by atom probe tomography. Numerous irregular interconnected ?' precipitates in the size range of ~30 to 50 nm were obtained even utilizing the fastest possible cooling rate. Diffuse ?/?' interface and far from equilibrium composition of ?' phase were observed in the fast-cooled sample, suggesting that ?' precipitation occurs via a spinodal decomposition at the very early stage.

  12. The early Archaean Itsaq Gneiss Complex of southern West Greenland: the importance of field observations in interpreting age and isotopic constraints for early terrestrial evolution

    NASA Astrophysics Data System (ADS)

    Nutman, Allen P.; Bennett, Vickie C.; Friend, Clark R. L.; Mcgregor, Victor R.

    2000-09-01

    Geochemical and isotopic studies of small volumes of variably preserved? 3600 Ma rocks in gneiss complexes are crucial for documenting early Earth history. In the Itsaq Gneiss Complex of the Nuuk region, West Greenland, there is dispute whether the granitic ( sensu lato) orthogneisses dominating it are mainly products of a single ca. 3650 Ma crust formation "super event," or whether they formed in several unrelated events between ca. 3850 and 3560 Ma. Which of these interpretations of the dates is correct has major implications regarding what the whole rock radiogenic isotopic record (Pb/Pb, Sm/Nd, Rb/Sr) reveals about continental crust formation and early terrestrial differentiation. There is also debate whether some West Greenland metasedimentary rocks with 12C/ 13C data interpreted as evidence for life are? 3850 Ma or only? 3650 Ma old. Establishing the correct age for these rocks is important for debates concerning early surficial environments and origin of life. Controversies have arisen because of different approaches taken by different workers, specifically with respect to how much emphasis is placed on field geology in interpreting dates and isotopic data. In this paper, field observations and sampling from low strain zones, where the origin and geological context of the rocks are best preserved and understood, are closely integrated with U-Pb zircon dates and cathodoluminescence (CL) imagery of the zircons. This approach shows that most single-phase, well-preserved, meta-granitoid samples have simple zircon populations dominated by oscillatory-zoned prismatic grains formed when their host magmas crystallized. On the other hand, migmatites and some strongly deformed-banded gneisses have much more complex zircon populations. The combined field evidence and zircon geochronology on the Itsaq Gneiss Complex demonstrate that 1) some areas contain exposed orthogneisses formed during multiple magmatic/thermal events between ca. 3850 and 3560 Ma and are not (as suggested by Kamber and Moorbath, 1998) dominated by ca. 3650 Ma granitoids containing abundant> 3650 Ma zircons inherited from cryptic, unexposed, older rocks; 2) abundant,? 3750 Ma granitoids are present, which are locally well-preserved; 3) some water-lain sediments reported as showing C isotope evidence for life were deposited as early as 3850 Ma; 4) the whole-rock Sm/Nd isochron approach fails to distinguish with any confidence 3650 Ma from 3800 Ma rocks, 5) however, it reinforces previous indications for markedly depleted (? + 2.5 ? Nd) domains in the pre-3750 Ma mantle.

  13. Proposed observations of gravity waves from the early Universe via "Millikan oil drops"

    E-print Network

    Chiao, R Y

    2006-01-01

    Pairs of Planck-mass drops of superfluid helium coated by electrons (i.e., ``Millikan oil drops''), when levitated in a superconducting magnetic trap, can be efficient quantum transducers between electromagnetic (EM) and gravitational (GR) radiation. This leads to the possibility of a Hertz-like experiment, in which EM waves are converted at the source into GR waves, and then back-converted at the receiver from GR waves back into EM waves. Detection of the gravity-wave analog of the cosmic microwave background using these drops can discriminate between various theories of the early Universe.

  14. An Observational Analysis of Behavior in Depressed Preschoolers: Further Validation of Early-Onset Depression

    ERIC Educational Resources Information Center

    Luby, Joan L.; Sullivan, Jill; Belden, Andy; Stalets, Melissa; Blankenship, Samantha; Spitznagel, Edward

    2006-01-01

    Objective: To investigate whether higher levels of negative and lower levels of positive behaviors could be observed in a sample of depressed preschoolers. Support for the validity of preschool depression is now available; however, objective evidence of negative behaviors among depressed preschoolers is needed. Method: A structured observational…

  15. Basin-scale, integrated observations of the early 21st century multiyear drought in southeast Australia

    Microsoft Academic Search

    Marc J. Leblanc; Paul Tregoning; Guillaume Ramillien; Sarah O. Tweed; Adam Fakes

    2009-01-01

    The Murray-Darling Basin in southeast Australia is experiencing one of the most severe droughts observed recently in the world, driven by several years of rainfall deficits and record high temperatures. This paper provides new basin-scale observations of the multiyear drought, integrated to a degree rarely achieved on such a large scale, to assess the response of water resources and the

  16. HST Observations of Early Spring Dust Storms in the North Polar Region of Mars

    Microsoft Academic Search

    P. B. James; M. J. Wolff; S. W. Lee; R. T. Clancy; J. F. Bell III; L. J. Martin

    1997-01-01

    Local dust clouds are fairly common near the edge of the subliming south polar cap of Mars, but previous observations of the corresponding season in the north have not revealed such activity. The most recent cycle of Hubble Space Telescope observations commenced shortly after the spring equinox and revealed interesting dust activity near the edge of the north seasonal cap.

  17. Early lidar observations of the June 1991 Pinatubo eruption plume at Mauna Loa Observatory, Hawaii

    Microsoft Academic Search

    Thomas E. Defoor; Elmer Robinson; Steven Ryan

    1992-01-01

    The Pinatubo plume was first observed by lidar on 1 July 1991. During July and August the observable effects from this plume increased in intensity in terms of aerosol optical properties, plume height, and broad-band solar radiation. Preliminary data analysis shows that the plume over Hawaii arrived in three generalized pulses or waves on approximately 3 July, 24 July, and

  18. Adoption of an electronic observation chart with an integrated early warning scoring system on pilot wards: a descriptive report.

    PubMed

    Nwulu, Ugochi; Westwood, David; Edwards, Debby; Kelliher, Fiona; Coleman, Jamie J

    2012-07-01

    The charting of physiological variables in hospital inpatients allows for recognition and treatment of deteriorating patients. The use of electronic records to capture patients' vital signs is still in its infancy in the United Kingdom. The main objective of this article was to describe the adoption of an electronic observation charting function integrated into an established bedside e-prescribing record system on acute wards in a large English university hospital. This new function also has the capability of contacting Critical Care Outreach and clinical staff when patients deteriorate. Data captured over a 4-month period from the pilot wards showed that 80% of observation sets were completed sufficiently to produce early warning scores over the time period. A daily average of 419 Standardized Early Warning Score produced 74 alerts to clinical staff, and two critical alarms per day were e-mailed to the Outreach team. The wards showed different levels of completeness of observations (from 69% to 92%). Although a good overall rate of completeness of physiological data was found, traditional gaps in observation recording documented in the literature (eg, recording of respiratory rate) were still apparent. This system can be used for audit for targeted staff education and to evaluate the Critical Care Outreach service. PMID:22525045

  19. Indian astronomy and the transits of Venus. 1: The early observations

    NASA Astrophysics Data System (ADS)

    Kapoor, R. C.

    2013-11-01

    This paper, the first of two, is about sightings and astronomical observations of transits of Venus across the disk of the Sun made from the Indian region. The period covered in this first paper is from ancient times up to and including the 1769 transit. The sources of the information presented here range from some classical texts and historiographies to publications and records of institutions, and accounts by individuals. Of particular interest is the 1761 transit, which was observed from atop the Governor's house in Madras by the Reverend William Hirst, who made a significant observation. During ingress he noticed a nebulosity about the planet, which he attributed to the atmosphere of Venus, and this was duly recorded in his paper reporting the transit observation that appeared in the Philosophical Transactions of the Royal Society of London. However, in a recent analysis, Pasachoff and Sheehan (2012) have shown that it was not the Cytherian atmosphere that Hirst and other astronomers observed in 1761.

  20. TEST FUSION IN ADULT FORAMINIFERA: A REVIEW WITH NEW OBSERVATIONS OF AN EARLY EOCENE NUMMULITES SPECIMEN

    PubMed Central

    Ferràndez-Cañadell, Carles; Briguglio, Antonino; Hohenegger, Johann; Wöger, Julia

    2015-01-01

    In foraminifera, so-called “double tests” usually arise due to abnormal growth originating mainly from twinning, but may also be caused by irregularities in the early chambers and by regeneration after test injury that modifies the direction of growth. A fourth cause of double tests has only rarely been reported: the fusion of the tests of two adult individuals. We studied an early Eocene Nummulites double test consisting of two adult individuals that fused after an extended period of independent growth. The specimen was studied using computed tomography with micrometric resolution (micro-CT) that allowed bi- and three-dimensional visualization of the internal structure. Before fusion each individual test had 30–36 chambers, which, by comparison with growth rates in recent nummulitids, implies at least three months of independent growth. After fusion, the compound test grew in two spirals that fused after about one whorl and then continued in a single spiral. To fuse their tests, either adult individuals have to be forced to do so or the allorecognition (ability to distinguish between self and another individual) mechanisms must fail. A possible explanation for the merged Nummulites tests in this study is forced fusion in attached individuals after surviving ingestion and digestion by a metazoan. Alternatively, environmental stress could lead to a failure of allorecognition mechanisms and/or foraminiferal motility. Once fused, subsequent growth seems to be determined mainly by the relative orientation of individual tests. In any case, the frequency in which adult fusion occurs remains unknown.

  1. Swift and Fermi Observations of the Early Afterglow of the Short Gamma-Ray Burst 090510

    Microsoft Academic Search

    M. De Pasquale; P. Schady; N. P. M. Kuin; M. J. Page; P. A. Curran; S. Zane; S. R. Oates; S. T. Holland; A. A. Breeveld; E. A. Hoversten; G. Chincarini; D. Grupe; A. A. Abdo; M. Ackermann; M. Ajello; M. Axelsson; L. Baldini; J. Ballet; G. Barbiellini; M. G. Baring; D. Bastieri; K. Bechtol; R. Bellazzini; B. Berenji; E. Bissaldi; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; A. Bouvier; J. Bregeon; A. Brez; M. S. Briggs; M. Brigida; P. Bruel; T. H. Burnett; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; S. Carrigan; J. M. Casandjian; C. Cecchi; Ö. Çelik; A. Chekhtman; J. Chiang; S. Ciprini; R. Claus; J. Cohen-Tanugi; V. Connaughton; J. Conrad; C. D. Dermer; A. de Angelis; F. de Palma; B. L. Dingus; E. do Couto e. Silva; P. S. Drell; R. Dubois; D. Dumora; C. Farnier; C. Favuzzi; S. J. Fegan; G. Fishman; W. B. Focke; M. Frailis; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; N. Giglietto; F. Giordano; T. Glanzman; G. Godfrey; J. Granot; J. Greiner; I. A. Grenier; J. E. Grove; L. Guillemot; S. Guiriec; A. K. Harding; M. Hayashida; E. Hays; D. Horan; R. E. Hughes; M. S. Jackson; G. Jóhannesson; A. S. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; N. Kawai; M. Kerr; R. M. Kippen; J. Knödlseder; D. Kocevski; M. Kuss; J. Lande; L. Latronico; M. Lemoine-Goumard; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; A. Makeev; M. N. Mazziotta; J. E. McEnery; S. McGlynn; C. Meegan; P. Mészáros; C. Meurer; P. F. Michelson; W. Mitthumsiri; T. Mizuno; C. Monte; M. E. Monzani; E. Moretti; A. Morselli; I. V. Moskalenko; S. Murgia; P. L. Nolan; J. P. Norris; E. Nuss; M. Ohno; T. Ohsugi; N. Omodei; E. Orlando; J. F. Ormes; W. S. Paciesas; D. Paneque; J. H. Panetta; D. Parent; V. Pelassa; M. Pepe; M. Pesce-Rollins; F. Piron; T. A. Porter; R. Preece; S. Rainò; R. Rando; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; S. Ritz; L. S. Rochester; A. Y. Rodriguez; M. Roth; F. Ryde; H. F.-W. Sadrozinski; A. Sander; P. M. Saz Parkinson; J. D. Scargle; T. L. Schalk; C. Sgrò; E. J. Siskind; P. D. Smith; G. Spandre; P. Spinelli; M. Stamatikos; J.-L. Starck; F. W. Stecker; M. S. Strickman; D. J. Suson; H. Tajima; H. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; D. J. Thompson; L. Tibaldo; K. Toma; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. Uehara; T. L. Usher; A. J. van der Horst; V. Vasileiou; N. Vilchez; V. Vitale; A. von Kienlin; A. P. Waite; P. Wang; B. L. Winer; K. S. Wood; X. F. Wu; R. Yamazaki; T. Ylinen; M. Ziegler

    2010-01-01

    We present the observations of GRB090510 performed by the Fermi Gamma-Ray Space Telescope and the Swift observatory. This is a bright, short burst that shows an extended emission detected in the GeV range. Furthermore, its optical emission initially rises, a feature so far observed only in long bursts, while the X-ray flux shows an initial shallow decrease, followed by a

  2. Early afterglow evolution of x-ray flashes observed by Swift

    NASA Astrophysics Data System (ADS)

    Hullinger, Derek

    2006-06-01

    Gamma-ray bursts (GRBs) are bright flashes of gamma-ray energy that originate in distant galaxies and last only a matter of seconds before fading away, never to appear again. They are accompanied by longer-wavelength "afterglows" that fade away much more gradually and can be detected for up to several days or even weeks after the gamma-ray burst has vanished. In recent years, another phenomenon has been discovered that resembles gamma- ray bursts in almost every way, except that the radiated energy comes mostly from x-rays instead of gamma-rays. This new class of bursts has been dubbed"x- ray flashes" (XRFs). There is strong evidence to suggest that GRBs and XRFs are closely-related phenomena. The Swift mission, launched in November of 2004, is designed to answer many questions about GRBs and their cousins, XRFs---where they come from, what causes them, and why gamma-ray bursts and x-ray flashes differ. The key to the Swift mission is its ability to detect and determine the location of a burst in the sky and then autonomously point x-ray and optical telescopes at the burst position within seconds of the detection. This allows the measurement of the afterglow within 1--2 minutes after the burst, rather than several hours later, as was necessary with past missions. This early afterglow measurement is an important key to distinguishing between different theories that seek to explain the differences between XRFs and GRBs. This dissertation describes the calibration of the Burst Alert Telescope, which measures the spectral and temporal properties of GRBs and XRFs. It also presents a study of XRFs and GRBs detected by Swift, including the first analysis and comparison of the early afterglow properties of these phenomena. This study reveals interesting differences between the temporal properties of GRB and XRF afterglows and sets strong constraints on some theories that seek to explain XRF origins.

  3. A word of the Empirics: the ancient concept of observation and its recovery in early modern medicine.

    PubMed

    Pomata, Gianna

    2011-01-01

    The genealogy of observation as a philosophical term goes back to the ancient Greek astronomical and medical traditions, and the revival of the concept in the Renaissance also happened in the astronomical and medical context. This essay focuses primarily on the medical genealogy of the concept of observation. In ancient Greek culture, an elaboration of the concept of observation (t?r?sis) first emerged in the Hellenistic age with the medical sect of the Empirics, to be further developed by the ancient Sceptics. Basically unknown in the Middle Ages, the Empirics' conceptualisation of t?r?sis trickled back into Western medicine in the fourteenth century, but its meaning seems to have been fully recovered by European scholars only in the 1560s, concomitantly with the first Latin translation of the works of Sextus Empiricus. As a category originally associated with medical Scepticism, observatio was a new entry in early modern philosophy. Although the term gained wide currency in general scholarly usage in the seventeenth century, its assimilation into standard philosophical language was very slow. In fact, observatio does not even appear as an entry in the philosophical dictionaries until the eighteenth century--with one significant exception, the medical lexica, which featured the lemma, reporting its ancient Empiric definition, as early as 1564. PMID:21466002

  4. MATROID BASE POLYTOPE DECOMPOSITION II : SEQUENCE OF HYPERPLANE SPLITS

    E-print Network

    Paris-Sud XI, Université de

    MATROID BASE POLYTOPE DECOMPOSITION II : SEQUENCE OF HYPERPLANE SPLITS VANESSA CHATELAIN AND JORGE LUIS RAMÍREZ ALFONSÍN Abstract. This is a continuation of the early paper [3] concerning matroid base poly- tope decomposition. Here, we will present sufficient conditions on M so its base matroid polytope

  5. A novel system for in-situ observations of early hydration reactions in wet conditions in conventional SEM

    SciTech Connect

    Katz, A. [National Building Research Institute, Faculty of Civil and Environmental Engineering, Technion - Israel Institute of Technology, Haifa (Israel); Bentur, A. [National Building Research Institute, Faculty of Civil and Environmental Engineering, Technion - Israel Institute of Technology, Haifa (Israel)]. E-mail: bentur@tx.technion.ac.il; Kovler, K. [National Building Research Institute, Faculty of Civil and Environmental Engineering, Technion - Israel Institute of Technology, Haifa (Israel)

    2007-01-15

    A novel system enabling wet microscopy in conventional SEM is described and its performance for in-situ study of hydration reactions is demonstrated. The technology is based on a sealed specimen capsule, which is protected from the microscope vacuum by an electron-transparent partition membrane. Thus, the wet sample can be placed and observed in a 'conventional' SEM without the need for drying or employing environmental SEM. Early hydration reactions of gypsum and cement systems were followed during the first 24 h.

  6. LOOKING INTO THE FIREBALL: ROTSE-III AND SWIFT OBSERVATIONS OF EARLY GAMMA-RAY BURST AFTERGLOWS

    SciTech Connect

    Rykoff, E. S. [Physics Department, University of California at Santa Barbara, 2233B Broida Hall, Santa Barbara, CA 93106 (United States); Aharonian, F. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Akerlof, C. W.; Flewelling, H. A.; McKay, T. A. [Department of Physics, University of Michigan, Ann Arbor, MI 48109 (United States); Ashley, M. C. B.; Phillips, A. [School of Physics, Department of Astrophysics and Optics, University of New South Wales, Sydney, NSW 2052 (Australia); Barthelmy, S. D.; Gehrels, N.; Krimm, H. A. [NASA Goddard Space Flight Center, Laboratory for High Energy Astrophysics, Greenbelt, MD 20771 (United States); Goegues, E. [Faculty of Engineering and Sciences, Sabanci University, Orhanli-Tuzla, 34956 Istanbul (Turkey); Guever, T. [Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Kiziloglu, Ue. [Middle East Technical University, 06531 Ankara (Turkey); Oezel, M. [Cag Ueniversitesi, Faculty of Arts and Sciences, Yenice-Tarsus/Mersin (Turkey); Quimby, R. M. [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Rowell, G. [School of Chemistry and Physics, University of Adelaide, Adelaide 5005 (Australia); Rujopakarn, W. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Schaefer, B. E. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Smith, D. A. [Guilford College, Greensboro, NC 27410 (United States); Vestrand, W. T. [Los Alamos National Laboratory, NIS-2 MS D436, Los Alamos, NM 87545 (United States)], E-mail: erykoff@physics.ucsb.edu (and others)

    2009-09-01

    We report on a complete set of early optical afterglows of gamma-ray bursts (GRBs) obtained with the Robotic Optical Transient Search Experiment (ROTSE-III) telescope network from 2005 March through 2007 June. This set is comprised of 12 afterglows with early optical and Swift/X-Ray Telescope observations, with a median ROTSE-III response time of 45 s after the start of {gamma}-ray emission (8 s after the GCN notice time). These afterglows span 4 orders of magnitude in optical luminosity, and the contemporaneous X-ray detections allow multi-wavelength spectral analysis. Excluding X-ray flares, the broadband synchrotron spectra show that the optical and X-ray emission originate in a common region, consistent with predictions of the external forward shock in the fireball model. However, the fireball model is inadequate to predict the temporal decay indices of the early afterglows, even after accounting for possible long-duration continuous energy injection. We find that the optical afterglow is a clean tracer of the forward shock, and we use the peak time of the forward shock to estimate the initial bulk Lorentz factor of the GRB outflow, and find 100 {approx}< {gamma}{sub 0} {approx}< 1000, consistent with expectations.

  7. Morphological characteristics observed during early follicular development in perinatal MRL/MpJ mice.

    PubMed

    Yamashita, Yuma; Nakamura, Teppei; Otsuka-Kanazawa, Saori; Ichii, Osamu; Kon, Yasuhiro

    2015-02-01

    In perinatal mice, the ovary undergoes drastic morphological changes, as clusters of oocytes called nests break into smaller cysts and subsequently form individual follicles. We studied perinatal oocyte development in MRL/MpJ mice, and compared it to that observed in C57BL/6 mice between embryonic day 18.5 and postnatal day 4. Throughout the observation period, compared to C57BL/6 mice, MRL/MpJ mice displayed significantly fewer oocytes in their ovaries. Morphologically, there were no clear differences between the strains at embryonic day 18.5. However, the beginning of folliculogenesis, as evidenced by the expression of NOBOX oogenesis homeobox (Nobox) transcript and protein, was more enhanced in MRL/MpJ mice than in C57BL/6 mice at embryonic day 18.5 and postnatal day 0. In addition, developed follicles were more frequently observed in MRL/MpJ mice than in C57BL/6 mice between postnatal days 0 and 4. In conclusion, the oocyte development during nest breakdown and folliculogenesis was accelerated in MRL/MpJ mice when compared to that observed in C57BL/6 mice. PMID:25854085

  8. An Observational Study of Early Heterosexual Interaction at Middle School Dances

    ERIC Educational Resources Information Center

    Pellegrini, Anthony D.; Long, Jeffery D.

    2007-01-01

    In this longitudinal, observational study of heterosexual interaction at middle school dances we examined the degree to which boys' and girls' groups became more gender integrated over time. The results show groups became more integrated over time with the pattern differing by gender. Boys had a relatively low level of contact with girls over the…

  9. Educative Experiences and Early Childhood Science Education: A Deweyan Perspective on Learning to Observe

    ERIC Educational Resources Information Center

    Howes, Elaine V.

    2008-01-01

    This paper is a report of work conducted at an urban elementary professional development school in the eastern US. John Dewey's explication of "educative experiences" is applied to describe curriculum involving small animals as a basis for teaching science inquiry processes, particularly the process of observation. The analysis is qualitative and…

  10. The Early Development of Object Knowledge: A Study of Infants' Visual Anticipations during Action Observation

    ERIC Educational Resources Information Center

    Hunnius, Sabine; Bekkering, Harold

    2010-01-01

    This study examined the developing object knowledge of infants through their visual anticipation of action targets during action observation. Infants (6, 8, 12, 14, and 16 months) and adults watched short movies of a person using 3 different everyday objects. Participants were presented with objects being brought either to a correct or to an…

  11. Catecholamine-Induced Leukocytosis: Early Observations, Current Research, and Future Directions

    Microsoft Academic Search

    Robert J. Benschop; Mario Rodriguez-Feuerhahn; Manfred Schedlowski

    1996-01-01

    Recent studies demonstrate that acute psychological stress in man affects lymphocyte circulation. It has been suggested that catecholamines are responsible for these changes. The present review summarizes findings regarding catecholamine-induced lympho- and leukocytosis, starting with observations dating back to the beginning of this century. Particular attention is given to the mechanisms of this phenomenon and the potential site of origin

  12. Thermal decomposition products of butyraldehyde

    NASA Astrophysics Data System (ADS)

    Hatten, Courtney D.; Kaskey, Kevin R.; Warner, Brian J.; Wright, Emily M.; McCunn, Laura R.

    2013-12-01

    The thermal decomposition of gas-phase butyraldehyde, CH3CH2CH2CHO, was studied in the 1300-1600 K range with a hyperthermal nozzle. Products were identified via matrix-isolation Fourier transform infrared spectroscopy and photoionization mass spectrometry in separate experiments. There are at least six major initial reactions contributing to the decomposition of butyraldehyde: a radical decomposition channel leading to propyl radical + CO + H; molecular elimination to form H2 + ethylketene; a keto-enol tautomerism followed by elimination of H2O producing 1-butyne; an intramolecular hydrogen shift and elimination producing vinyl alcohol and ethylene, a ?-C-C bond scission yielding ethyl and vinoxy radicals; and a ?-C-C bond scission yielding methyl and CH2CH2CHO radicals. The first three reactions are analogous to those observed in the thermal decomposition of acetaldehyde, but the latter three reactions are made possible by the longer alkyl chain structure of butyraldehyde. The products identified following thermal decomposition of butyraldehyde are CO, HCO, CH3CH2CH2, CH3CH2CH=C=O, H2O, CH3CH2C?CH, CH2CH2, CH2=CHOH, CH2CHO, CH3, HC?CH, CH2CCH, CH3C?CH, CH3CH=CH2, H2C=C=O, CH3CH2CH3, CH2=CHCHO, C4H2, C4H4, and C4H8. The first ten products listed are direct products of the six reactions listed above. The remaining products can be attributed to further decomposition reactions or bimolecular reactions in the nozzle.

  13. Childhood Maltreatment and Prospectively Observed Quality of Early Care as Predictors of Antisocial Personality Disorder Features

    PubMed Central

    Shi, Zhenyu; Bureau, Jean-Francois; Easterbrooks, M. Ann; Zhao, Xudong; Lyons-Ruth, Karlen

    2011-01-01

    Few studies have evaluated the separate contributions of maltreatment and ongoing quality of parent-child interaction to the etiology of antisocial personality features using a prospective longitudinal design. 120 low-income young adults (aged 18-23) were assessed for extent of ASPD features on the Structured Clinical Interview for Diagnosis-Axis II, for presence of maltreatment on the Conflict Tactics Scale, Traumatic Experiences Scale, and Adult Attachment Interview, and for referral in infancy to parent-infant clinical services. Fifty-six of these families had been studied longitudinally since the first year of life. In infancy, attachment disorganization and disrupted mother-infant interaction were assessed; in middle childhood, disorganized-controlling attachment behaviors were reliably rated. In kindergarten and second grade, behavior problems were assessed by teacher report. In cross-sectional analyses, maltreatment was significantly associated with ASPD features but did not account for the independent effect of early referral to parent-infant services on ASPD features. In longitudinal analyses, maternal withdrawal in infancy predicted the extent of ASPD features twenty years later, independently of childhood abuse. In middle childhood, disorganized attachment behavior and maladaptive behavior at school added to prediction of later ASPD features. Antisocial features in young adulthood have precursors in the minute-to-minute process of parent-child interaction beginning in infancy. PMID:22754051

  14. Observations of the Early Evening Boundary-Layer Transition Using a Small Unmanned Aerial System

    NASA Astrophysics Data System (ADS)

    Bonin, Timothy; Chilson, Phillip; Zielke, Brett; Fedorovich, Evgeni

    2013-01-01

    The evolution of the lower portion of the planetary boundary layer is investigated using the Small Multifunction Research and Teaching Sonde (SMARTSonde), an unmanned aerial vehicle developed at the University of Oklahoma. The study focuses on the lowest 200 m of the atmosphere, where the most noticeable thermodynamic changes occur during the day. Between October 2010 and February 2011, a series of flights was conducted during the evening hours on several days to examine the vertical structure of the lower boundary layer. Data from a nearby Oklahoma Mesonet tower was used to supplement the vertical profiles of temperature, humidity, and pressure, which were collected approximately every 30 min, starting 2 h before sunset and continuing until dusk. From the profiles, sensible and latent heat fluxes were estimated. These fluxes were used to diagnose the portion of the boundary layer that was most affected by the early evening transition. During the transition period, a shallow cool and moist layer near the ground was formed, and as the evening progressed the cooling affected an increasingly shallower layer just above the surface.

  15. Early resuscitation intensity as a surrogate for bleeding severity and early mortality in the PRospective, Observational, Multicenter, Major Trauma Transfusion (PROMMTT) Study

    PubMed Central

    Rahbar, Elaheh; Fox, Erin E.; del Junco, Deborah J.; Harvin, John A.; Holcomb, John B.; Wade, Charles E.; Schreiber, Martin A.; Rahbar, Mohammad H.; Bulger, Eileen M.; Phelan, Herb A.; Brasel, Karen J.; Alarcon, Louis H.; Myers, John G.; Cohen, Mitchell J.; Muskat, Peter; Cotton, Bryan A.

    2013-01-01

    Background The classic definition of MT, ?10 units red blood cells (RBCs) in 24 hours, has never been demonstrated as a valid surrogate for severe hemorrhage and can introduce survival bias. In addition, the definition fails to capture other products that the clinician may have immediately available during the initial resuscitation. Assuming that units of resuscitative fluids reflect patient illness, our objective was to identify a rate of resuscitation intensity (RI) that could serve as an early surrogate of sickness for patients with substantial bleeding post-injury. Methods Adult patients surviving at least 30 minutes post-admission and receiving ?1 RBC within 6 hours of admission from ten US Level 1 trauma centers were enrolled in the PRospective Observational Multicenter Major Trauma Transfusion study. Total fluid units were calculated as the sum of the number of crystalloid units (1 L=1 unit), colloids (0.5 L=1 unit) and blood products (1 RBC=1 unit, 1 plasma=1 unit, 6 pack platelets=1 unit). Univariable and multivariable logistic regressions were used to evaluate associations between RI and 6-hour mortality, adjusting for age, center, penetrating injury, weighted Revised Trauma Score, and Injury Severity Score. Results 1096 eligible patients received resuscitative fluids within 30 minutes, including 620 transfused with blood products. Despite varying products utilized, the total fluid RI was similar across all sites (3.2±2.5 units). Patients who received ?4 units of any resuscitative fluid had a 6-hour mortality rate of 14.4% vs. 4.5% in patients who received <4 units. The adjusted odds ratio of 6-hour mortality for patients receiving ?4 units within 30 minutes was 2.1 (95% Confidence Interval: 1.2–3.5). Conclusions Resuscitation with ?4 units of any fluid was significantly associated with 6-hour mortality. This study suggests that early RI regardless of fluid type can be used as a surrogate for sickness and mortality in severely bleeding patients. Level of Evidence PROMMTT is a prospective observational study, Level II. PMID:23778506

  16. Earth Observations for Early Detection of Agricultural Drought in Countries at Risk: Contributions of the Famine Early Warning Systems Network (FEWS NET) (Invited)

    NASA Astrophysics Data System (ADS)

    Verdin, J. P.; Rowland, J.; Senay, G. B.; Funk, C. C.; Budde, M. E.; Husak, G. J.; Jayanthi, H.

    2013-12-01

    The Group on Earth Observations' Global Agricultural Monitoring (GEOGLAM) implementation plan emphasizes the information needs of countries at risk of food insecurity emergencies. Countries in this category are often vulnerable to disruption of agricultural production due to drought, while at the same time they lack well developed networks of in-situ observations to support early drought detection. Consequently, it is vital that Earth observations by satellites supplement those available from surface stations. The USGS, in its role as a FEWS NET implementing partner, has recently developed a number of new applications of satellite observations for this purpose. (1) In partnership with the University of California, Santa Barbara, a 30+ year time series of gridded precipitation estimates (CHIRPS) has been developed by blending NOAA GridSat B1 geostationary thermal infrared imagery with station observations using robust geostatistical methods. The core data set consists of pentadal (5-daily) accumulations from 1981-2013 at 0.05 degree spatial resolution between +/- 50 degrees latitude. Validation has been recently completed, and applications for gridded crop water balance calculations and mapping the Standardized Precipitation Index are in development. (2) Actual evapotranspiration (ETa) estimates using MODIS Land Surface Temperature (LST) data at 1-km have been successfully demonstrated using the operational Simplified Surface Energy Balance model with 8-day composites from the LPDAAC. A new, next-day latency implementation using daily LST swath data from the NASA LANCE server is in development for all the crop growing regions of the world. This ETa processing chain follows in the footsteps of (3) the expedited production of MODIS 250-meter NDVI images every five days at USGS EROS, likewise using LANCE daily swath data as input since 2010. Coverage includes Africa, Central Asia, the Middle East, Central America, and the Caribbean. (4) A surface water point monitoring method for pastoralist areas has been successfully demonstrated. It involves mapping small surface water bodies with ASTER and Landsat imagery, delineating their catchment areas with SRTM elevation data, and maintaining a continuous water balance calculation with satellite rainfall and weather model evaporation estimates to track relative fullness of these ephemeral water bodies. Piloted with NASA funds in partnership with Texas A&M University, the technique is now being implemented across the Sahel. (5) To move beyond monitoring and early warning to disaster risk management, loss exceedence probability functions are being derived for crop production shortfalls in FEWS NET countries. Drought hazard indicators, based on both ETa and crop water balance modeling forced by CHIRPS, have been used to develop regional crop drought risk models. In the case of ETa, the drought risk model provides the basis for index insurance in experiments being conducted in Senegal. A program of training events with GEO partners ensures that the data sets and applications are made available to scientists in FEWS NET countries.

  17. High-resolution Observations of Molecular Gas in the Early-type Dwarf Galaxy NGC 404

    NASA Astrophysics Data System (ADS)

    Taylor, Christopher L.; Petitpas, Glen R.; del Rio, M. S.

    2015-06-01

    We present Berkeley–Illinois–Maryland Association CO (1–0) observations of the nearby dwarf elliptical galaxy NGC 404. The detected CO emission is concentrated in a small feature, slightly larger than the beam size, at the center of the optical galaxy. For an assumed CO-to-H2 conversion factor of 2.3 × {{10}20} (K km s?1)?1, the molecular gas mass is 9.0 × {{10}6} M?. The velocity field suggests rotation, with a position angle ?90° different from previous single-dish observations. Both position angles are different from that of the extended H i distribution detected by del Rió et al. The lack of agreement between the postion angle of the CO velocity field and other position angles suggests an external origin for the central molecular gas clump in NGC 404.

  18. Modeling the energy spectrum of precipitating electrons with early RBSP observations and test particle simulations

    NASA Astrophysics Data System (ADS)

    Kersten, K.; Cattell, C. A.; Wygant, J. R.; Breneman, A. W.; Bonnell, J. W.; Tao, J.; Blake, B.; Kletzing, C.; Kurth, W. S.; Roth, I.; Zhang, S.

    2012-12-01

    The Radiation Belt Storm Probe satellites (RBSP) allow for unprecedented simultaneous measurement of both high time resolution VLF wave fields and local energetic electron pitch angle and energy distributions. By coupling these measurements with relativistic test particle simulations, we attempt to assess the role of oblique whistler wave-particle interactions in the acceleration, transport, and loss of energetic radiation belt electrons. The relativistic test particle code is capable of tracking the individual trajectories of large populations of particles interacting with oblique whistler mode waves through bounce and gyromotion in a magnetic dipole guide field scaled to Earth's surface field, allowing for simple quantification of test particle scattering and loss. By weighting input energy and pitch angle distributions by those observed with RBSP, we attempt to model the expected energy spectrum of the precipitating electron population, e.g., what may be observed at BARREL due to wave-particle interactions in the radiation belts.

  19. Observing Preschoolers’ Social-Emotional Behavior: Structure, Foundations, and Prediction of Early School Success

    Microsoft Academic Search

    Susanne A. Denham; Hideko Hamada Bassett; Sara K. Thayer; Melissa S. Mincic; Yana S. Sirotkin; Katherine Zinsser

    2012-01-01

    Social-emotional behavior of 352 3- and 4-year-olds attending private childcare and Head Start programs was observed using the Minnesota Preschool Affect Checklist, Revised (MPAC-R). Goals of the investigation included (a) using MPAC-R data to extract a shortened version, MPAC-R\\/S, comparing structure, internal consistency, test–retest reliability, and stability of both versions; and, using the shortened measure, to examine (b) age, gender,

  20. Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C 454.3

    Microsoft Academic Search

    A. A. Abdo; M. Ackermann; M. Ajello; W. B. Atwood; M. Axelsson; L. Baldini; J. Ballet; G. Barbiellini; D. Bastieri; M. Battelino; B. M. Baughman; K. Bechtol; R. Bellazzini; B. Berenji; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; A. Bouvier; J. Bregeon; A. Brez; M. Brigida; P. Bruel; T. H. Burnett; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; J. M. Casandjian; E. Cavazzuti; C. Cecchi; E. Charles; S. Chaty; A. Chekhtman; C. C. Cheung; J. Chiang; S. Ciprini; R. Claus; J. Cohen-Tanugi; L. R. Cominsky; J. Conrad; L. Costamante; S. Cutini; C. D. Dermer; A. de Angelis; F. de Palma; S. W. Digel; E. do Couto e. Silva; D. Donato; P. S. Drell; R. Dubois; D. Dumora; C. Farnier; C. Favuzzi; W. B. Focke; L. Foschini; M. Frailis; L. Fuhrmann; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; B. Giebels; N. Giglietto; P. Giommi; F. Giordano; T. Glanzman; G. Godfrey; I. A. Grenier; M.-H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; Y. Hanabata; A. K. Harding; R. C. Hartman; M. Hayashida; E. Hays; R. E. Hughes; G. Jóhannesson; A. S. Johnson; R. P. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; N. Kawai; M. Kerr; J. Knödlseder; M. L. Kocian; F. Kuehn; M. Kuss; L. Latronico; S.-H. Lee; M. Lemoine-Goumard; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; G. M. Madejski; A. Makeev; E. Massaro; M. N. Mazziotta; J. E. McEnery; S. McGlynn; C. Meurer; P. F. Michelson; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; N. Omodei; E. Orlando; J. F. Ormes; D. Paneque; J. H. Panetta; D. Parent; V. Pelassa; M. Pepe; M. Pesce-Rollins; F. Piron; T. A. Porter; S. Rainò; R. Rando; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; L. C. Reyes; S. Ritz; L. S. Rochester; A. Y. Rodriguez; F. Rahoui; F. Ryde; H. F.-W. Sadrozinski; R. Sambruna; D. Sanchez; A. Sander; P. M. Saz Parkinson; C. Sgrò; M. S. Shaw; D. A. Smith; P. D. Smith; G. Spandre; P. Spinelli; J.-L. Starck; M. S. Strickman; D. J. Suson; H. Tajima; H. Takahashi; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; D. J. Thompson; L. Tibaldo; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; N. Vilchez; M. Villata; V. Vitale; A. P. Waite; B. L. Winer; K. S. Wood; T. Ylinen; J. A. Zensus; M. Ziegler

    2009-01-01

    This is the first report of Fermi Gamma-Ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope, covering 2008 July 7-October 6, indicate strong, highly variable gamma-ray emission with an average flux of ~3 × 10-6 photons cm-2 s-1, for energies >100 MeV. The gamma-ray

  1. GHRS observations and theoretical modeling of early type stars in R136a

    Microsoft Academic Search

    A. de Koter; S. Heap; I. Hubeny; T. Lanz; J. Hutchings; S. Maran; W. Schmutz

    1994-01-01

    We present the first spectroscopic observations of individual stars in R136a, the most dense part of the starburst cluster 30 Doradus in the LMC. Spectra of two stars are scheduled to be obtained with the GHRS on board the HST: R136a5, the brightest of the complex and R136a2, a Wolf-Rayet star of type WN. The 30 Doradus cluster is the

  2. Early evolution of the Galactic halo revealed from Hipparcos observations of metal-poor stars

    E-print Network

    Masashi Chiba; Yuzuru Yoshii

    1997-10-15

    The kinematics of 122 red giants and 124 RR Lyrae variables in the solar neighborhood is studied using accurate measurements of their proper motions by the Hipparcos astrometry satellite, combined with the published photometric distances, metal abundances and radial velocities. A majority of these sample stars have metal abundances with [Fe/H]<-1 and thus represent the old stellar populations in the Galaxy. The halo component with [Fe/H]<-1.6 is characterized by no systemic rotation and a radially elongated velocity ellipsoid. About 16% of such metal-poor stars have low orbital eccentricities e<0.4, and we see no evidence for the correlation between [Fe/H] and e. Based on the model for the e distribution of orbits, we show that this fraction of low e stars for [Fe/H]<-1.6 is explained from the halo component alone, without introducing the extra disk component claimed by recent workers. This is also supported by no significant change of the e distribution with the height from the Galactic plane. This metal-weak thick disk component appears to comprise only about 10% for -1.6< [Fe/H]<-1 and 20% for -1.4<[Fe/H]<-1. It is also verified that the disk has the mean rotation of about 195 km/s and the vertical extent of 1 kpc, which is consistent with the thick disk dominating at [Fe/H]=-0.6 to -1. The implications of these results for the early evolution of the Galaxy are also presented.

  3. The early Earth Observing System reference handbook: Earth Science and Applications Division missions, 1990-1997

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Prior to the launch of the Earth Observing System (EOS) series, NASA will launch and operate a wide variety of new earth science satellites and instruments, as well as undertake several efforts collecting and using the data from existing and planned satellites from other agencies and nations. These initiatives will augment the knowledge base gained from ongoing Earth Science and Applications Division (ESAD) programs. This volume describes three sets of ESAD activities -- ongoing exploitation of operational satellite data, research missions with upcoming launches between now and the first launch of EOS, and candidate earth probes.

  4. The accelerations of the earth and moon from early astronomical observations

    NASA Technical Reports Server (NTRS)

    Muller, P. M.; Stephenson, F. R.

    1975-01-01

    An investigation has compiled a very large amount of data on central or near central solar eclipses as recorded in four principal ancient sources (Greek and Roman classics, medieval European chronicles, Chinese annals and astronomical treatises, and Late Babylonian astronomical texts) and applied careful data selectivity criteria and statistical methods to obtain reliable dates, magnitudes, and places of observation of the events, and thereby made estimates of the earth acceleration and lunar acceleration. The basic conclusion is that the lunar acceleration and both tidal and nontidal earth accelerations have been essentially constant during the period from 1375 B.C. to the present.

  5. High-resolution observations of tungsten liner collapse and early jet formation

    SciTech Connect

    Winer, K.A.; Breithaupt, R.D.; Muelder, S.A.; Baum, D.W.

    1996-07-01

    High-resolution photography of collapsing tungsten-lined shaped charges has revealed surface texturing both similar to and strikingly different from that previously observed during copper liner collapse. The behavior of three types of tungsten-lined shaped charges, with different liner designs and high explosives but with similar tungsten processing, were characterized by image-converter camera and fast- framing camera photography, and flash x-ray radiography. 120-mm- diameter, trumpet-shaped Octol charges produced surface blistering near the base of the tungsten liner, probably due to inhomogeneities near the liner-explosive interface resulting from cast loading. 148- mm-diameter, quasi-conical LX-14 charges produced smooth shocked- surface texture similar to that observed in conical, copper-lined LX- 14 (Viper) charges. 81-mm-diameter, conical LX-20 charges produced severe radial texturing throughout the collapsing tungsten liner, which transitioned to azimuthal banding on the jet surface. For each type of charge, obscuring debris from the tungsten jet tip prevented clear imaging of the jet surface at late time. 8 refs., 6 figs., 2 tabs.

  6. A SOLAR CYCLE LOST IN 1793-1800: EARLY SUNSPOT OBSERVATIONS RESOLVE THE OLD MYSTERY

    SciTech Connect

    Usoskin, Ilya G. [Sodankylae Geophysical Observatory (Oulu unit), University of Oulu (Finland); Mursula, Kalevi [Department of Physical Sciences, University of Oulu (Finland); Arlt, Rainer [Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam (Germany); Kovaltsov, Gennady A. [Ioffe Physical-Technical Institute of RAS, 194021 St. Petersburg (Russian Federation)], E-mail: ilya.usoskin@oulu.fi

    2009-08-01

    Because of the lack of reliable sunspot observations, the quality of the sunspot number series is poor in the late 18th century, leading to the abnormally long solar cycle (1784-1799) before the Dalton minimum. Using the newly recovered solar drawings by the 18-19th century observers Staudacher and Hamilton, we construct the solar butterfly diagram, i.e., the latitudinal distribution of sunspots in the 1790s. The sudden, systematic occurrence of sunspots at high solar latitudes in 1793-1796 unambiguously shows that a new cycle started in 1793, which was lost in the traditional Wolf sunspot series. This finally confirms the existence of the lost cycle that has been proposed earlier, thus resolving an old mystery. This Letter brings the attention of the scientific community to the need of revising the sunspot series in the 18th century. The presence of a new short, asymmetric cycle implies changes and constraints to sunspot cycle statistics, solar activity predictions, and solar dynamo theories, as well as for solar-terrestrial relations.

  7. Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario

    USGS Publications Warehouse

    Walsh, Maureen G.; Lantry, Brian F.; Boscarino, Brent; Bowen, Kelly; Gerlofsma, Jocelyn; Schaner, Ted; Back, Richard; Questel, Jennifer; Smythe, A. Garry; Cap, Roberta; Goehle, Michael; Young, Bryan; Chalupnicki, Marc; Johnson, James H.; McKenna, James E.

    2010-01-01

    Hemimysis anomala, a Ponto-Caspian littoral mysid, is an emerging Great Lakes invader that was discovered in Lakes Michigan and Ontario in 2006. Similar to the native mysid Mysis diluviana, Hemimysis exhibits a diel vertical migration pattern but generally inhabits shallower and warmer waters than M. diluviana. Because basic information on the distribution, habitat use, and biology of Hemimysis in the Great Lakes is scarce, the potential for food web disruption by Hemimysis cannot easily be predicted. Preliminary observations indicate widespread invasion of Hemimysis in Lake Ontario. In this study, we confirm the presence of Hemimysis at sites spanning the northern and southern shores of Lake Ontario and the presence of the individuals during winter months. In one horizontal tow in November 2007, over 26,000 individuals were collected with a length range of 4.4 to 9.0. mm and an average caloric density of 611. cal/g wet weight. The most effective methods for sampling Hemimysis were horizontal tows with either a zooplankton net in the water column or a benthic sled near the lake bottom. Although more quantitative data on the life history and distribution of this species is necessary, our preliminary observations support the prediction that the potential for Hemimysis to impact the nearshore food web in Lake Ontario appears high.

  8. BIMA Observations of Early Stages of High-Mass Star Formation

    NASA Astrophysics Data System (ADS)

    Wyrowski, Friedrich; Sridharan, T. K.; Menten, Karl M.; Schilke, Peter

    1999-10-01

    To systematically search for high mass protostars without any free-free emission, meaning that no UC HII has formed yet, we studied 70 candidate sources, selected according to their FIR radiation characteristics and their non-detection in Galaxy wide cm continuum surveys (Ramesh & Sridharan 1997), in the water vapor and ammonia lines with the 100 m and, in case of detections, with the 30 m telescope (Menten et al. 1999; Sridharan et al. 1999). This lead to the detection of several new water masers, ubiquitous outflow activity, and several new hot core sources as evident from bright CH3CN emission. As a follow up we started interferometric observations of selected sources using the BIMA array. Here we present observations of IRAS 18089-1732, a source at a distance of 3.6 kpc with about 4 x 104 solar luminosities derived from the IRAS fluxes. The massive core is seen in 3 mm dust continuum emission and is associated with compact (~ 0.03 pc) and hot (T ~ 100 K) strong line emission of CH3CN suggesting an enhancement and heating of this molecule through very recent evaporation of dust grains by a newly born high mass (proto) star.

  9. Quality versus Quantity: The Use of Observation by Early Childhood Educators in Improving the Performance of Children Enrolled in Preschool Programs in Ghana

    ERIC Educational Resources Information Center

    Tackie-Ofosu, Vivian; Bentum, Kwesi

    2013-01-01

    In the current study, the authors explored how early childhood educators used observation to support children in the learning environment. The objectives set were to find out the observation methods teachers used, ascertain their understanding of child observation, find out activities children undertook, and how teachers documented what children…

  10. Predicted and observed early effects of combined alpha and beta lung irradiation

    SciTech Connect

    Scott, B.R.; Hahn, F.F.; Snipes, M.B.; Newton, G.J.; Eidson, A.F.; Mauderly, J.L.; Boecker, B.B. (Inhalation Toxicology Research Institute, Albuquerque, NM (USA))

    1990-12-01

    The nonstochastic radiobiological effects of combined alpha and beta irradiation of the lungs of rats from inhaled radionuclides were studied. Both respiratory functional morbidity at 18 mo and mortality from radiation pneumonitis within 18 mo after exposure were examined for rats exposed to the beta-emitter 147Pm, the alpha-emitter 238Pu, or both combined. The results were used to validate hazard-function models that were developed (1) for respiratory functional morbidity at 18 mo and (2) for lethality from radiation pneumonitis within 18 mo. Both models were found to adequately predict the experimental observations for chronic alpha plus beta irradiation of the lung. Based on this 18-mo study, a relative biological effectiveness of approximately seven was obtained for 238Pu alpha radiation compared to 147Pm beta radiation for both respiratory functional morbidity and lethality from radiation pneumonitis. However, the relative biological effectiveness for the alpha radiation is likely to increase with longer follow-up.

  11. Observations of ionospheric electron content near the geomagnetic equator in Nha Trang (SRV) - Early results

    NASA Astrophysics Data System (ADS)

    Jakowski, N.; Jungstand, A.; Binh, T. T.; Khuang, T. X.; Tan, N. D.

    Faraday-rotation observations have been started in Nha Trang in September 1986 using the ETS-II geostationary satellite. The subionospheric point at 11.4 deg N, 110.8 deg E is located close to the geomagnetic equator. The daytime variation occurs as a broad noon-afternoon maximum, sometimes modified by the well known noontime biteout effect. The ionospheric electron content is closely related to changes in the low-level solar activity during the day as well as during night. A seasonal variation could not be derived from the data. During the declining phase, a period of reduced loss has been found around 19-21 LT, indicated by a shoulder in the Faraday records. This phenomenon is assumed to be caused by an eastward-directed electric field.

  12. ROSAT PSPC observations of two X-ray-faint early-type galaxies: NGC 4365 and NGC 4382

    NASA Technical Reports Server (NTRS)

    Fabbiano, G.; Kim, D.-W.; Trinchieri, G.

    1994-01-01

    We present the results of ROSAT Positive Sensitive Proportional Counter (PSPC) observations of the two early-type galaxies NGC 4365 and NGC 4382. These galaxies are among those observed with Einstein to have the lowest X-ray to optical flux ratios of early-type galaxies. The PSCP data show that for radii r greater than 50 arcsec the radial distributions of the X-ray surface brightness are consistent with the optical distributions of King (1978). We also find that these galaxies have X-ray spectra significantly different from those observed in X-ray-bright ellipticals, with a relative excess of counts detected in the softest spectral channels. This confirms earlier Einstein results. The characteristics of the ROSAT PSPC do not allow us to discriminate between possible spectral models. If we adopt a two-component thermal model on the grounds of physical plausibility, we find that the spectral data can be fitted with a very soft optically thin component, with kT approximately 0.2 keV, and a hard component with kT greater than (1.0-1.5) keV. The hard component has a luminosity consistent with that expected from the integrated emission of a population of low mass-X-ray binaries in these galaxies; the nature of the very soft component is more speculative. Candidates include the coronal emission of late-type stars, supersoft X-ray sources, RS CVn, and perhaps a hot Interstellar Medium (ISM). Alternatively, the spectal data may be fitted with a 0.6-1 keV bremsstrahlung spectrum (expontential plus Gaunt), and may suggest the presence of a totally new population of X-ray sources.

  13. Early Ultraviolet, Optical and X-Ray Observations of the Type IIP SN 2005cs in M51 with Swift

    E-print Network

    Peter J. Brown; Luc Dessart; Stephen T. Holland; Stefan Immler; Wayne Landsman; Stephane Blondin; Alexander J. Blustin; Alice Breeveld; Gulab C. Dewangan; Neil Gehrels; Robert B. Hutchins; Robert P. Kirshner; Keith O. Mason; Paolo A. Mazzali; Peter Milne; Maryam Modjaz; Peter W. A. Roming

    2006-12-19

    We report early photospheric-phase observations of the Type IIP Supernova (SN) 2005cs obtained by Swift's Ultraviolet-Optical and X-Ray Telescopes. Observations started within two days of discovery and continued regularly for three weeks. During this time the V-band magnitude remained essentially constant, while the UV was initially bright but steadily faded until below the brightness of an underlying UV-bright HII region. This UV decay is similar to SNe II observed by the International Ultraviolet Explorer. UV grism spectra show the P-Cygni absorption of MgII 2798A, indicating a photospheric origin of the UV flux. Based on non-LTE model atmosphere calculations with the CMFGEN code, we associate the rapid evolution of the UV flux with the cooling of the ejecta, the peak of the spectral energy distribution (SED) shifting from ~700A on June 30th to ~1200A on July 5th. Furthermore, the corresponding recombination of the ejecta, e.g., the transition from FeIII to FeII, induces considerable strengthening of metal line-blanketing at and above the photosphere, blocking more effectively this fading UV flux. SN2005cs was not detected in X-rays, and the upper limit to the X-ray luminosity yields a limit to the mass loss rate of the progenitor of about 10^-5 solar masses per year. Overall, Swift presents a unique opportunity to capture the early and fast evolution of Type II SNe in the UV, providing additional constraints on the reddening, the SED shortward of 4000A, and the ionization state and temperature of the photon-decoupling regions.

  14. Nucleon spin decomposition and orbital angular momentum in the nucleon

    NASA Astrophysics Data System (ADS)

    Wakamatsu, Masashi

    2014-09-01

    To get a complete decomposition of nucleon spin is a fundamentally important homework of QCD. In fact, if our researches end up without accomplishing this task, a tremendous efforts since the 1st discovery of the nucleon spin crisis would end in the air. We now have a general agreement that there are at least two physically inequivalent gauge-invariant decompositions of the nucleon. In these two decompositions, the intrinsic spin parts of quarks and gluons are just common. What discriminate these two decompositions are the orbital angular momentum (OAM) parts. The OAMs of quarks and gluons appearing in the first decomposition are the so-called ``mechanical'' OAMs, while those appearing in the second decomposition are the generalized (gauge-invariant) ``canonical'' ones. By this reason, these decompositions are broadly called the ``mechanical'' and ``canonical'' decompositions of the nucleon spin. Still, there remains several issues, which have not reached a complete consensus among the experts. (See the latest recent). In the present talk, I will mainly concentrate on the practically most important issue, i.e. which decomposition is more favorable from the observational viewpoint. There are two often-claimed advantages of canonical decomposition. First, each piece of this decomposition satisfies the SU(2) commutation relation or angular momentum algebra. Second, the canonical OAM rather than the mechanical OAM is compatible with free partonic picture of constituent orbital motion. In the present talk, I will show that both these claims are not necessarily true, and push forward a viewpoint that the ``mechanical'' decomposition is more physical in that it has more direct connection with observables. I also emphasize that the nucleon spin decomposition accessed by the lattice QCD analyses is the ``mechanical'' decomposition not the ``canonical'' one. The recent lattice QCD studies of the nucleon spin decomposition are also briefly overviewed.

  15. Estimates for Lorentz factors of gamma-ray bursts from early optical afterglow observations

    SciTech Connect

    Hascoët, Romain; Beloborodov, Andrei M. [Physics Department and Columbia Astrophysics Laboratory, Columbia University, 538 West 120th Street, New York, NY 10027 (United States); Daigne, Frédéric; Mochkovitch, Robert, E-mail: hascoet@astro.columbia.edu [Institut d'Astrophysique de Paris, UMR 7095 Université Pierre et Marie Curie-CNRS, 98 bis boulevard Arago, F-75014 Paris (France)

    2014-02-10

    The peak time of optical afterglow may be used as a proxy to constrain the Lorentz factor ? of the gamma-ray burst (GRB) ejecta. We revisit this method by including bursts with optical observations that started when the afterglow flux was already decaying; these bursts can provide useful lower limits on ?. Combining all analyzed bursts in our sample, we find that the previously reported correlation between ? and the burst luminosity L {sub ?} does not hold. However, the data clearly show a lower bound ?{sub min} that increases with L {sub ?}. We suggest an explanation for this feature: explosions with large jet luminosities and ? < ?{sub min} suffer strong adiabatic cooling before their radiation is released at the photosphere; they produce weak bursts, barely detectable with present instruments. To test this explanation, we examine the effect of adiabatic cooling on the GRB location in the L {sub ?} – ? plane using a Monte Carlo simulation of the GRB population. Our results predict detectable on-axis 'orphan' afterglows. We also derive upper limits on the density of the ambient medium that decelerates the explosion ejecta. We find that the density in many cases is smaller than expected for stellar winds from normal Wolf-Rayet progenitors. The burst progenitors may be peculiar massive stars with weaker winds, or there might exist a mechanism that reduces the stellar wind a few years before the explosion.

  16. GHRS observations and theoretical modeling of early type stars in R136a

    NASA Astrophysics Data System (ADS)

    de Koter, A.; Heap, S.; Hubeny, I.; Lanz, T.; Hutchings, J.; Lamers, H. J. G. L. M.; Maran, S.; Schmutz, W.

    1994-05-01

    We present the first spectroscopic observations of individual stars in R136a, the most dense part of the starburst cluster 30 Doradus in the LMC. Spectra of two stars are scheduled to be obtained with the GHRS on board the HST: R136a5, the brightest of the complex and R136a2, a Wolf-Rayet star of type WN. The 30 Doradus cluster is the only starburst region in which individual stars can be studied. Therefore, quantitative knowledge of the basic stellar parameters will yield valuable insight into the formation of massive stars in starbursts and into their subsequent evolution. Detailed modeling of the structure of the atmosphere and wind of these stars will also lead to a better understanding of the mechanism(s) that govern their dynamics. We present the first results of our detailed quantitative spectral analysis using state-of-the-art non-LTE model atmospheres for stars with extended and expanding atmospheres. The models are computed using the Improved-Sobolev Approximation wind code (ISA-WIND) of de Koter, Schmutz & Lamers (1993, A&A 277, 561), which has been extended to include C, N and Si. Our model computations are not based on the core-halo approximation, but use a unified treatment of the photosphere and wind. This approach is essential for Wolf-Rayet stars. Our synthetic spectra, dominated by the P Cygni profiles of the UV resonance lines, also account for the numerous weak metal lines of photospheric origin.

  17. SPITZER OBSERVATIONS OF PASSIVE AND STAR-FORMING EARLY-TYPE GALAXIES: AN INFRARED COLOR-COLOR SEQUENCE

    SciTech Connect

    Temi, Pasquale [Astrophysics Branch, NASA/Ames Research Center, MS 245-6, Moffett Field, CA 94035 (United States); Brighenti, Fabrizio; Mathews, William G., E-mail: pasquale.temi@nasa.go, E-mail: mathews@ucolick.or, E-mail: fabrizio.brighenti@unibo.i [University of California Observatories/Lick Observatory, Board of Studies in Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2009-12-20

    We describe the infrared properties of a large sample of early-type galaxies, comparing data from the Spitzer archive with Ks-band emission from the Two Micron All Sky Survey. While most representations of this data result in correlations with large scatter, we find a remarkably tight relation among colors formed by ratios of luminosities in Spitzer-Multiband Imaging Photometer bands (24, 70, and 160 mum) and the Ks band. Remarkably, this correlation among E and S0 galaxies follows that of nearby normal galaxies of all morphological types. In particular, the tight infrared color-color correlation for S0 galaxies alone follows that of the entire Hubble sequence of normal galaxies, roughly in order of galaxy type from ellipticals to spirals to irregulars. The specific star formation rate (SFR) of S0 galaxies estimated from the 24 mum luminosity increases with decreasing K-band luminosity (or stellar mass) from essentially zero, as with most massive ellipticals, to rates typical of irregular galaxies. Moreover, the luminosities of the many infrared-luminous S0 galaxies can significantly exceed those of the most luminous (presumably post-merger) E galaxies. SFRs in the most infrared-luminous S0 galaxies approach 1-10 solar masses per year. Consistently, with this picture we find that while most early-type galaxies populate an infrared red sequence, about 24% of the objects (mostly S0s) are in an infrared blue cloud together with late-type galaxies. For those early-type galaxies also observed at radio frequencies, we find that the far-infrared luminosities correlate with the mass of neutral and molecular hydrogen, but the scatter is large. This scatter suggests that the star formation may be intermittent or that similar S0 galaxies with cold gaseous disks of nearly equal mass can have varying radial column density distributions that alter the local and global SFRs.

  18. Curvature perturbations in the early universe: Theoretical models and observational tests

    NASA Astrophysics Data System (ADS)

    Vallinotto, Alberto

    A very general prediction of inflation is that the power spectrum of density perturbations is characterized by a spectral index ns which is scale independent and approximately equal to unity. Drawing from the potential reconstruction method and adopting the slow-roll parameter expansion technique, we derive all possible single field inflationary potentials that would lead to a scale invariant density spectral index, consistent with current observations. In the process, a new method to determine the functional form of the inflationary potential in the slow roll approximation is devised, based on the reparametrization of the field dynamics with respect to the slow roll parameter epsilon which also allowed to show that under the assumptions made the investigation proved to be exhaustive and that no other solutions are available. Next, we focus on the fact that there exist a large class of inflationary models currently ruled out because the predicted production of curvature perturbations during the slow-roll stage results exponentially suppressed. We investigate whether an alternative mechanism for the generation of curvature perturbations can be devised for such a class of models. In the process, it is shown that it is sufficient for the inflationary potential to exhibit a broken symmetry to successfully convert isocurvature perturbations, which are excited during the slow-roll stage, into curvature perturbations thanks to an inhomogeneous decay stage. This conclusion is general, requiring as a sufficient condition only the fact that the inflation potential is characterized by a broken symmetry. Finally, we show that the perturbations thus produced are generally characterized by a non-negligible degree of non-gaussianity, which then provides a clear experimental signature for experimental detection or rejection.

  19. Early evolution of a stratospheric volcanic eruption cloud as observed with TOMS and AVHRR

    USGS Publications Warehouse

    Schneider, D.J.; Rose, William I., Jr.; Coke, L.R.; Bluth, G.J.S.; Sprod, I.E.; Krueger, A.J.

    1999-01-01

    This paper is a detailed study of remote sensing data from the total ozone mapping spectrometer (TOMS) and the advanced very high resolution radiometer (AVHRR) satellite detectors, of the 1982 eruption of El Chicho??n, Mexico. The volcanic cloud/atmosphere interactions in the first four days of this eruption were investigated by combining ultraviolet retrievals to estimate the mass of sulfur dioxide in the volcanic cloud [Krueger et al., 1995] with thermal infrared retrievals of the size, optical depth, and mass of fine-grained (1-10 ??m radius) volcanic ash [Wen and Rose, 1994]. Our study provides the first direct evidence of gravitational separation of ash from a stratospheric, gas-rich, plinian eruption column and documents the marked differences in residence times of volcanic ash and sulfur dioxide in volcanic clouds. The eruption column reached as high as 32 km [Carey and Sigurdsson, 1986] and was injected into an atmosphere with a strong wind shear, which allowed for an observation of the separation of sulfur dioxide and volcanic ash. The upper, more sulfur dioxide-rich part of the cloud was transported to the west in the stratosphere, while the fine-grained ash traveled to the south in the troposphere. The mass of sulfur dioxide released was estimated at 7.1 ?? 109 kg with the mass decreasing by approximately 4% 1 day after the peak. The mass of fine-grained volcanic ash detected was estimated at 6.5 ?? 109 kg, amounting to about 0.7% of the estimated mass of the ash which fell out in the mapped ash blanket close to the volcano. Over the following days, 98% of this remaining fine ash was removed from the volcanic cloud, and the effective radius of ash in the volcanic cloud decreased from about 8 ??m to about 4 ??m. Copyright 1999 by the American Geophysical Union.

  20. The 2014 Mw 6.0 Napa Earthquake, California: Observations from Real-time GPS-enhanced Earthquake Early Warning

    NASA Astrophysics Data System (ADS)

    Johanson, I. A.; Grapenthin, R.; Allen, R. M.

    2014-12-01

    Recently, progress has been made to demonstrate feasibility and benefits of including real-time GPS (rtGPS) in earthquake early warning and rapid response systems. While most concepts have yet to be integrated into operational environments, the Berkeley Seismological Laboratory is currently running an rtGPS based finite fault inversion scheme in true real-time, which is triggered by the seismic-based ShakeAlert system and then sends updated earthquake alerts to a test receiver. The Geodetic Alarm System (G-larmS) was online and responded to the 2014 Mw6.0 South Napa earthquake in California. We review G-larmS' performance during this event and for 13 aftershocks, and we present rtGPS observations and real-time modeling results for the main shock. The first distributed slip model and a magnitude estimate of Mw5.5 were available 24 s after the event origin time, which could be reduced to 14 s after a bug fix (~8 s S-wave travel time, ~6 s data latency). The system continued to re-estimate the magnitude once every second: it increased to Mw5.9 3 s after the first alert and stabilized at Mw5.8 after 15 s. G-larmS' solutions for the subsequent small magnitude aftershocks demonstrate that Mw~6.0 is the current limit for alert updates to contribute back to the seismic-based early warning system.

  1. The 2014 Mw 6.0 Napa earthquake, California: Observations from real-time GPS-enhanced earthquake early warning

    NASA Astrophysics Data System (ADS)

    Grapenthin, Ronni; Johanson, Ingrid; Allen, Richard M.

    2014-12-01

    Recently, progress has been made to demonstrate feasibility and benefits of including real-time GPS (rtGPS) in earthquake early warning and rapid response systems. Most concepts, however, have yet to be integrated into operational environments. The Berkeley Seismological Laboratory runs an rtGPS-based finite fault inversion scheme in real time. This system (G-larmS) detected the 2014 Mw 6.0 South Napa earthquake in California. We review G-larmS' performance during this event and 13 aftershocks and present rtGPS observations and real-time modeling results for the main shock. The first distributed slip model and magnitude estimates were available 24s after the event origin time, which, after optimizations, was reduced to 14s (?8s S wave travel time, ?6s data latency). G-larmS' solutions for the aftershocks (that had no measurable surface displacements) demonstrate that, in combination with the seismic early warning magnitude, Mw 6.0 is our current resolution limit.

  2. Autonomous Gaussian Decomposition

    NASA Astrophysics Data System (ADS)

    Lindner, Robert R.; Vera-Ciro, Carlos; Murray, Claire E.; Stanimirovi?, Snežana; Babler, Brian; Heiles, Carl; Hennebelle, Patrick; Goss, W. M.; Dickey, John

    2015-04-01

    We present a new algorithm, named Autonomous Gaussian Decomposition (AGD), for automatically decomposing spectra into Gaussian components. AGD uses derivative spectroscopy and machine learning to provide optimized guesses for the number of Gaussian components in the data, and also their locations, widths, and amplitudes. We test AGD and find that it produces results comparable to human-derived solutions on 21 cm absorption spectra from the 21 cm SPectral line Observations of Neutral Gas with the EVLA (21-SPONGE) survey. We use AGD with Monte Carlo methods to derive the H i line completeness as a function of peak optical depth and velocity width for the 21-SPONGE data, and also show that the results of AGD are stable against varying observational noise intensity. The autonomy and computational efficiency of the method over traditional manual Gaussian fits allow for truly unbiased comparisons between observations and simulations, and for the ability to scale up and interpret the very large data volumes from the upcoming Square Kilometer Array and pathfinder telescopes.

  3. Purely Dry Mergers do not Explain the Observed Evolution of Massive Early-type Galaxies since z ~ 1

    NASA Astrophysics Data System (ADS)

    Sonnenfeld, Alessandro; Nipoti, Carlo; Treu, Tommaso

    2014-05-01

    Several studies have suggested that the observed size evolution of massive early-type galaxies (ETGs) can be explained as a combination of dry mergers and progenitor bias, at least since z ~ 1. In this paper we carry out a new test of the dry-merger scenario based on recent lensing measurements of the evolution of the mass density profile of ETGs. We construct a theoretical model for the joint evolution of the size and mass density profile slope ?' driven by dry mergers occurring at rates given by cosmological simulations. Such dry-merger model predicts a strong decrease of ?' with cosmic time, inconsistent with the almost constant ?' inferred from observations in the redshift range 0 < z < 1. We then show with a simple toy model that a modest amount of cold gas in the mergers—consistent with the upper limits on recent star formation in ETGs—is sufficient to reconcile the model with measurements of ?'. By fitting for the amount of gas accreted during mergers, we find that models with dissipation are consistent with observations of the evolution in both size and density slope, if ~4% of the total final stellar mass arises from the gas accreted since z ~ 1. Purely dry merger models are ruled out at >99% CL. We thus suggest a scenario where the outer regions of massive ETGs grow by accretion of stars and dark matter, while small amounts of dissipation and nuclear star formation conspire to keep the mass density profile constant and approximately isothermal.

  4. Observation of early shell-dopant mix in OMEGA direct-drive implosions and comparisons with radiation-hydrodynamic simulations

    SciTech Connect

    Baumgaertel, J. A.; Bradley, P. A.; Hsu, S. C.; Cobble, J. A.; Hakel, P.; Tregillis, I. L.; Krasheninnikova, N. S.; Murphy, T. J.; Schmitt, M. J.; Shah, R. C.; Obrey, K. D.; Batha, S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Johns, H.; Joshi, T.; Mayes, D.; Mancini, R. C.; Nagayama, T. [Physics Department, University of Nevada, Reno, Nevada 89557 (United States)

    2014-05-15

    Temporally, spatially, and spectrally resolved x-ray image data from direct-drive implosions on OMEGA were interpreted with the aid of radiation-hydrodynamic simulations. Neither clean calculations nor those using a turbulent mix model can explain fully the observed migration of shell-dopant material (titanium) into the core. Shell-dopant migration was observed via time-dependent, spatially integrated spectra, and spatially and spectrally resolved x-ray images of capsule implosions and resultant dopant emissions. The titanium emission was centrally peaked in narrowband x-ray images. In post-processed clean simulations, the peak titanium emission forms in a ring in self-emission images as the capsule implodes. Post-processed simulations with mix reproduce trends in time-dependent, spatially integrated spectra, as well having centrally peaked Ti emission in synthetic multiple monochromatic imager. However, mix simulations still do not transport Ti to the core as is observed in the experiment. This suggests that phenomena in addition to the turbulent mix must be responsible for the transport of Ti. Simple diffusion estimates are unable to explain the early Ti mix into the core. Mechanisms suggested for further study are capsule surface roughness, illumination non-uniformity, and shock entrainment.

  5. Purely dry mergers do not explain the observed evolution of massive early-type galaxies since z ? 1

    SciTech Connect

    Sonnenfeld, Alessandro; Treu, Tommaso [Physics Department, University of California, Santa Barbara, CA 93106 (United States); Nipoti, Carlo, E-mail: sonnen@physics.ucsb.edu [Department of Physics and Astronomy, Bologna University, viale Berti-Pichat 6/2, I-40127 Bologna (Italy)

    2014-05-10

    Several studies have suggested that the observed size evolution of massive early-type galaxies (ETGs) can be explained as a combination of dry mergers and progenitor bias, at least since z ? 1. In this paper we carry out a new test of the dry-merger scenario based on recent lensing measurements of the evolution of the mass density profile of ETGs. We construct a theoretical model for the joint evolution of the size and mass density profile slope ?' driven by dry mergers occurring at rates given by cosmological simulations. Such dry-merger model predicts a strong decrease of ?' with cosmic time, inconsistent with the almost constant ?' inferred from observations in the redshift range 0 < z < 1. We then show with a simple toy model that a modest amount of cold gas in the mergers—consistent with the upper limits on recent star formation in ETGs—is sufficient to reconcile the model with measurements of ?'. By fitting for the amount of gas accreted during mergers, we find that models with dissipation are consistent with observations of the evolution in both size and density slope, if ?4% of the total final stellar mass arises from the gas accreted since z ? 1. Purely dry merger models are ruled out at >99% CL. We thus suggest a scenario where the outer regions of massive ETGs grow by accretion of stars and dark matter, while small amounts of dissipation and nuclear star formation conspire to keep the mass density profile constant and approximately isothermal.

  6. Climate forcing due to the 8200 cal yr BP event observed at Early Neolithic sites in the eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Weninger, Bernhard; Alram-Stern, Eva; Bauer, Eva; Clare, Lee; Danzeglocke, Uwe; Jöris, Olaf; Kubatzki, Claudia; Rollefson, Gary; Todorova, Henrieta; van Andel, Tjeerd

    2006-11-01

    We explore the hypothesis that the abrupt drainage of Laurentide lakes and associated rapid switch of the North Atlantic thermohaline circulation 8200 yr ago had a catastrophic influence on Neolithic civilisation in large parts of southeastern Europe, Anatolia, Cyprus, and the Near East. The event at 8200 cal yr BP is observed in a large number of high-resolution climate proxies in the Northern Hemisphere, and in many cases corresponds to markedly cold and arid conditions. We identify the relevant archaeological levels of major Neolithic settlements in Central Anatolia, Cyprus, Greece and Bulgaria, and examine published stratigraphic, architectural, cultural and geoarchaeological studies for these sites. The specific archaeological events and processes we observe at a number of these sites during the study interval 8400-8000 cal yr BP lead us to refine some previously established Neolithisation models. The introduction of farming to South-East Europe occurs in all study regions (Thrace, Macedonia, Thessaly, Bulgaria) near 8200 cal yr BP. We observe major disruptions of Neolithic cultures in the Levant, North Syria, South-East Anatolia, Central Anatolia and Cyprus, at the same time. We conclude that the 8200 cal yr BP aridity event triggered the spread of early farmers, by different routes, out of West Asia and the Near East into Greece and Bulgaria.

  7. 4, 19772002, 2004 decomposition

    E-print Network

    Paris-Sud XI, Université de

    regeneration during the experiment and with ozone loss being catalytic to some degree. The initial uptakeACPD 4, 1977­2002, 2004 Ozone decomposition kinetics on alumina R. C. Sullivan et al. Title Page and Physics Discussions Ozone decomposition kinetics on alumina: effects of ozone partial pressure, relative

  8. Wavelet frequency decomposition method

    NASA Astrophysics Data System (ADS)

    Rieder, Andreas; Wells, Raymond O., Jr.; Zhou, Xiaodong

    1994-03-01

    A wavelet variation of the frequency decomposition multigrid method of Hackbusch is presented. The perfect reconstruction property of the wavelet system enable us to perform the convergence analysis of the frequency decomposition method. Some applications of this method are also presented.

  9. Facial Expression Decomposition

    Microsoft Academic Search

    Hongcheng Wang; Narendra Ahuja

    2003-01-01

    In this paper, we propose a novel approach for facial expression decomposition - Higher-Order Singular Value Decomposition (HOSVD), a natural generalization of matrix SVD. We learn the expression subspace and person subspace from a corpus of images showing seven basic facial expressions, rather than resort to expert-coded facial expression parameters as in (3). We propose a simulta- neous face and

  10. UV-dropout Galaxies in the GOODS-South Field from WFC3 Early Release Science Observations

    E-print Network

    Hathi, N P; Cohen, S H; Yan, H; Windhorst, R A; McCarthy, P J; O'Connell, R W; Koekemoer, A M; Rutkowski, M J; Balick, B; Bond, H E; Calzetti, D; Disney, M J; Dopita, M A; Frogel, J A; Hall, D N B; Holtzman, J A; Kimble, R A; Paresce, F; Saha, A; Silk, J I; Trauger, J T; Walker, A R; Whitmore, B C; Young, E T

    2010-01-01

    We combine new high sensitivity ultraviolet (UV) imaging from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) with existing deep HST/Advanced Camera for Surveys (ACS) optical images from the Great Observatories Origins Deep Survey (GOODS) program to identify UV-dropouts, which are Lyman break galaxy (LBG) candidates at z~1-3. These new HST/WFC3 observations were taken over 50 sq.arcmin in the GOODS-South field as a part of the Early Release Science program. The uniqueness of these new UV data is that they are observed in 3 UV/optical (WFC3 UVIS) channel filters (F225W, F275W and F336W), which allows us to identify three different sets of UV-dropout samples. We apply Lyman break dropout selection criteria to identify F225W-, F275W- and F336W-dropouts, which are z~1.7, 2.1 and 2.7 LBG candidates, respectively. We use multi-wavelength imaging combined with available spectroscopic and photometric redshifts to carefully access the validity of our UV-dropout candidates. Our results are as follows...

  11. BOLOCAM OBSERVATIONS OF TWO UNCONFIRMED GALAXY CLUSTER CANDIDATES FROM THE PLANCK EARLY SUNYAEV-ZEL'DOVICH SAMPLE

    SciTech Connect

    Sayers, J.; Czakon, N. G.; Bridge, C.; Golwala, S. R. [Division of Physics, Math, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Koch, P. M.; Lin, K.-Y.; Umetsu, K. [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Molnar, S. M., E-mail: jack@caltech.edu [LeCosPA Center, National Taiwan University, Taipei 10617, Taiwan (China)

    2012-04-10

    We present Bolocam observations of two galaxy cluster candidates reported as unconfirmed in the Planck early Sunyaev-Zel'dovich (eSZ) sample, PLCKESZ G115.71+17.52 and PLCKESZ G189.84-37.24. We observed each of these candidates with Bolocam at 140 GHz from the Caltech Submillimeter Observatory in 2011 October. The resulting images have white noise levels of {approx_equal} 30 {mu}K{sub CMB} arcmin in their central regions. We find a significant SZ decrement toward PLCKESZ G115.71. This decrement has a false detection probability of 5.3 Multiplication-Sign 10{sup -5}, and we therefore confirm PLCKESZ G115.71 as a cluster. The maximum SZ decrement toward PLCKESZ G189.84 corresponds to a false detection probability of 0.027, and it therefore remains as an unconfirmed cluster candidate. In order to make our SZ-derived results more robust, we have also analyzed data from the Wide-field Infrared Survey Explorer (WISE) at the location of each cluster candidate. We find an overdensity of WISE sources consistent with other clusters in the eSZ at the location of PLCKESZ G115.71, providing further evidence that it is a cluster. We do not find a significant overdensity of WISE sources at the location of PLCKESZ G189.84.

  12. Environmental effects of solar-thermal power systems: ecological observations during early testing of the Barstow 10-MWe pilot STPS

    SciTech Connect

    Turner, F.B. (ed.)

    1982-11-01

    Environmental measurements were continued at Solar One during 1982, while final steps in construction and early testing were carried out. Measurements of sand depths downwind (east) of the heliostat field indicated that some of the sand blown off the field (most of it between September 1979 and March 1980) has been carried farther east, reducing sand depths somewhat in areas just east of the field. Observations of birds between March and June 1982 revealed that (1) the natural avifauna of the field has been altered, although the area is still used for feeding by some icterids (larks, blackbirds) and aerial insectivores (swallows, swifts); (2) of 15 bird casualties ascribable to the presence and/or operation of Solar One, 12 followed collisions with heliostats, three resulted from incineration in heliostat beams; (3) the central receiver tower does not appear to be a source of mortality. Numbers of rodents (particularly kangaroo rats) trapped in areas downwind of the site declined steadily between 1978 and 1982 in areas both clost to the field and as far east as 600 m from the fence. The most likely interpretation of these changes is a reduction in reproductivity and/or early survival caused by four consecutive years (1978, 1979, 1980, 1981) of suboptimal autumn rainfall. Micrometeorological measurements in areas downwind of Solar One showed small effects on air temperatures (<0.5/sup 0/C), wind speeds (<0.4 m/sec), and evaporation rates (<1.5 ml/hr).Effects were detected only in areas 100 to 190 m from the east perimeter fence. Because these differences are so small, relative to natural heterogeneities, the effects of Solar One on rates of evaporation, air temperatures and wind speed will not affect the downwind biological community. The relavance of these findings to construction of a larger solar thermal power plant (e.g., Solar 100) are considered.

  13. Thermal Decomposition of Formaldehyde

    NASA Astrophysics Data System (ADS)

    Irdam, Erwin Ayandra

    The role of formaldehyde as a reactive intermediate in combustion is well recognized and this has led to numerous kinetic investigations of its decomposition. There are issues remaining to be resolved in the dissociation which include the construction of an accurate chain mechanism valid over a wide range of conditions and the determination of the branching ratio of the two possible dissociation channels, radical and molecular. This has been achieved with a combination of new shock tube laser-schlieren measurements and theory. The experiments were conducted using a trimer of formaldehyde, 1,3,5-trioxane, which is shown to dissociate exclusively to three molecules of formaldehyde, thus providing a convenient source of pure formaldehyde. The rate of dissociation of 1,3,5-trioxane dissociation is measured here over 900-1270K and extended using unimolecular reaction rate theory. The subsequent dissociation of formaldehyde is observed above 2200K and measured to 3200K. A chain mechanism for the formaldehyde decomposition derived from a combination of theory and laser-schlieren measurements has been constructed. This includes new measurements of the rate constant for the abstraction reaction, CH _2O + H to HCO + H _2. These measured rates are consistent with theoretical rates which show non-Arrhenius behavior at high temperature. The second order rate constant for the bond fission CH_2O + M to HCO + H + M, was extrapolated from the previous direct low temperature (1600-2000K) measurements using unimolecular rate theory. These laser-schlieren measurements are insensitive to the rate of terminating reactions involving formyl radicals and hydrogen atoms. The present kinetic mechanism with improved rate constants has been tested against previous experiments (1600-2600K) using IR emission, ARAS, and CO laser absorption giving quite satisfactory results. The branching ratio of the rate of the faster molecular dissociation, CH_2 O + (M) to CO + H _2 + (M) to that of the bond fission reaction, was estimated to lie around 2 or 3 over 2000 to 3000K. This ratio is consistent with a recent theoretical estimate and most experimental observations.

  14. FUSE Observations of the Magellanic Bridge Gas toward Two Early-Type Stars: Molecules, Physical Conditions, and Relative Abundance

    E-print Network

    N. Lehner

    2002-09-03

    We discuss FUSE observations of two early-type stars, DI1388 and DGIK975, in the low density and low metallicity gas of Magellanic Bridge (MB). Toward DI1388, the FUSE observations show molecular hydrogen, O VI, and numerous other atomic or ionic transitions in absorption, implying the presence of multiple gas phases in a complex arrangement. The relative abundance pattern in the MB is attributed to varying degrees of depletion onto dust similar to that of halo clouds. The N/O ratio is near solar, much higher than N/O in damped Ly-alpha systems, implying subsequent stellar processing to explain the origin of nitrogen in the MB. The diffuse molecular cloud in this direction has a low column density and low molecular fraction. H2 is observed in both the Magellanic Stream and the MB, yet massive stars form only in the MB, implying significantly different physical processes between them. In the MB some of the H2 could have been pulled out from the SMC via tidal interaction, but some also could have formed in situ in dense clouds where star formation might have taken place. Toward DGIK975, the presence of neutral, weakly and highly ionized species suggest that this sight line has also several complex gas phases. The highly ionized species of O VI, C IV, and Si IV toward both stars have very broad features, indicating that multiple components of hot gas at different velocities are present. Several sources (a combination of turbulent mixing layer, conductive heating, and cooling flows) may be contributing to the production of the highly ionized gas in the MB. Finally, this study has confirmed previous results that the high-velocity cloud HVC 291.5-41.2+80 is mainly ionized composed of weakly and highly ions. The high ion ratios are consistent with a radiatively cooling gas in a fountain flow model.

  15. Gauge- and frame-independent decomposition of nucleon spin

    SciTech Connect

    Wakamatsu, M. [Department of Physics, Faculty of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2011-01-01

    In a recent paper, we have shown that the way of gauge-invariant decomposition of the nucleon spin is not necessarily unique, but there still exists a preferable decomposition from the observational viewpoint. What was not complete in this argument is a fully satisfactory answer to the following questions. Does the proposed gauge-invariant decomposition, especially the decomposition of the gluon total angular momentum into its spin and orbital parts, correspond to observables which can be extracted from high-energy deep-inelastic-scattering measurements? Is this decomposition not only gauge invariant but also Lorentz frame independent, so that it is legitimately thought to reflect an intrinsic property of the nucleon? We show that we can answer both of these questions affirmatively by making full use of a gauge-invariant decomposition of the covariant angular-momentum tensor of QCD in an arbitrary Lorentz frame.

  16. Observing slow EEG activity from same area as spikes in paediatric patients with focal epilepsy by using signal decomposition and dipole

    E-print Network

    Observing slow EEG activity from same area as spikes in paediatric patients with focal epilepsy.vanrumste@esat.kuleuven.ac.be Introduction The background EEG in patients with focal epilepsy often shows abnormalities related of the epileptogenic source. The algorithm has been applied to eight EEGs of paediatric patients with focal epilepsy

  17. On the Helmert-blocking technique: its acceleration by block Choleski decomposition and formulae to insert observations into an adjusted network

    PubMed Central

    Del Rio, Eduardo; Oliveira, Leonardo

    2015-01-01

    The Helmert-blocking technique is a common approach to adjust large geodetic networks like Europeans and Brazilians. The technique is based upon a division of the network into partial networks called blocks. This way, the global network adjustment can be done by manipulating these blocks. Here we show alternatives to solve the block system that arises from the application of the technique. We show an alternative that optimizes its implementation as the elapsed processing time is decreased by about 33%. We also show that to insert observations into an adjusted network it is not necessary to readjust the whole network. We show the formulae to insert new observations into an adjusted network that are more efficient than simply readjusting the whole new network.

  18. A Multistage Position\\/Force Control for Constrained Robotic Systems With Friction: Joint-Space Decomposition, Linearization, and Multiobjective Observer\\/Controller Synthesis Using LMI Formalism

    Microsoft Academic Search

    Karim Khayati; Pascal Bigras; L.-A. Dessaint

    2006-01-01

    A historical review of constrained robot modeling and control strategies is first introduced. Next, a design of a motion\\/force controller for a constrained servo-robot, which is based on a commonly known modeling structure, is proposed. The contact between the end-effector and the environment is subject to frictional features. Accordingly, the control plant is based on the LuGre friction closed-loop observer.

  19. In situ X-ray observations of the decomposition of brucite and the graphite–diamond conversion in aqueous fluid at high pressure and temperature

    Microsoft Academic Search

    T. Okada; W. Utsumi; H. Kaneko; M. Yamakata; O. Shimomura

    2002-01-01

    An experimental technique to make real-time observations at high pressure and temperature of the diamond-forming process\\u000a in candidate material of mantle fluids as a catalyst has been established for the first time. In situ X-ray diffraction experiments\\u000a using synchrotron radiation have been performed upon a mixture of brucite [Mg(OH)2] and graphite as starting material. Brucite decomposes into periclase (MgO) and

  20. New observations of the early land plant Eocooksonia Doweld from the Pridoli (Upper Silurian) of Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Xue, Jinzhuang; Wang, Qi; Wang, Deming; Wang, Yi; Hao, Shougang

    2015-04-01

    As an early land plant previously reported from the Upper Silurian (Pridoli) of Xinjiang, Northwest China and Central Kazakhstan, the circumscription of Eocooksonia sphaerica (Senkevitsch) Doweld remains ill-defined because of the paucity of specimens and poor preservation in marine deposits. New specimens of this plant are described from the Pridoli-aged Wutubulake Formation of the Junggar Basin, Xinjiang. New observations and comparisons with the type material from Kazakhstan confirm the pseudomonopodial branching pattern, which forms an apparent main axis with lateral dichotomously branching systems. Our specimens demonstrate that the terminal sporangia of Eocooksonia Doweld consist of a central body and a border with four to eight elongate-triangular emergences, a character shown in the published illustrations of the type material but not mentioned in the original diagnosis. Eocooksonia may be close to Cooksonia Lang and Pertonella Fanning, Edwards et Richardson in affinities, particularly to the latter that has terminal discoidal sporangia with spiny emergences. It is deduced that the sporangial central body of Eocooksonia contains sporogenous tissues, which are covered by a distal surface wall with radiated emergences. One sporangium specimen of an unnamed plant is also described from the Wutubulake Formation of Xinjiang; it shows a central body with a wide border lacking emergences, and represents a taxon superficially similar to Eocooksonia.

  1. Usual Clinical Practice for Early Supported Discharge after Stroke with Continued Rehabilitation at Home: An Observational Comparative Study

    PubMed Central

    Tistad, Malin; von Koch, Lena

    2015-01-01

    Introduction Based on randomised controlled trials, evidence exists that early supported discharge (ESD) from the hospital with continued rehabilitation at home has beneficial effects after stroke; however, the effects of ESD service in regular clinical practice have not been investigated. The purpose of the current study was to compare ESD service with conventional rehabilitation in terms of patient outcomes, caregiver burden at 3 and 12 months and the use and costs of healthcare during the first year after stroke. Material and Methods This study was a subgroup analysis of a longitudinal observational study of patients who received care in the stroke unit at Karolinska University Hospital in Sweden. Patients who met the inclusion criteria for ESD in previous experimental studies were included. The patients were referred to available rehabilitation services at discharge, and comparisons between those who received ESD service (the ESD group, n = 40) and those who received conventional rehabilitation (the NoESD group, n = 110) were performed with regard to independence in activities of daily living (ADL), the frequency of social activities, life satisfaction, and caregiver burden and the use and costs of healthcare during the first year after stroke. Results At 3 and 12 months, no differences were observed with regard to patient outcomes; however, ESD was associated with a lower caregiver burden (p = 0.01) at 12 months. The initial length of stay (LOS) at the hospital was 8 days for the ESD group and 15 days for the NoESD group (p = 0.02). The median number of outpatient rehabilitation contacts was 20.5 for the ESD group (81% constituting ESD service) and 3 for the NoESD group (p<0.001). There was no difference between the groups with regard to overall healthcare costs. Conclusions ESD service in usual clinical practice renders similar health benefits as conventional rehabilitation but a different pattern of resource use and with released capacity in acute stroke care. PMID:26186211

  2. A-train CALIOP and MLS observations of early winter Antarctic polar stratospheric clouds and nitric acid in 2008

    NASA Astrophysics Data System (ADS)

    Lambert, A.; Santee, M. L.; Wu, D. L.; Chae, J. H.

    2012-03-01

    A-train Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Microwave Limb Sounder (MLS) observations are used to investigate the development of polar stratospheric clouds (PSCs) and the gas-phase nitric acid distribution in the early 2008 Antarctic winter. Observational evidence of gravity-wave activity is provided by Atmospheric Infrared Sounder (AIRS) radiances and infrared spectroscopic detection of nitric acid trihydrate (NAT) in PSCs is obtained from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). Goddard Earth Observing System Data Assimilation System (GEOS-5 DAS) analyses are used to derive Lagrangian trajectories and to determine temperature-time histories of air parcels. We use CALIOP backscatter and depolarization measurements to classify PSCs and the MLS measurements to determine the corresponding gas-phase HNO3 as a function of temperature. For liquid PSCs the uptake of HNO3 follows the theoretical equilibrium curve for supercooled ternary solutions (STS), but at temperatures about 1 K lower as determined from GEOS-5. In the presence of solid phase PSCs, above the ice frost-point, the HNO3 depletion occurs over a wider range of temperatures (+2 to -7 K) distributed about the NAT equilibrium curve. Rapid gas-phase HNO3 depletion is first seen by MLS from from 23-25 May 2008, consisting of a decrease in the volume mixing ratio from 14 ppbv (parts per billion by volume) to 7 ppbv on the 46-32 hPa (hectopascal) pressure levels and accompanied by a 2-3 ppbv increase by renitrification at the 68 hPa pressure level. The observed region of depleted HNO3 is substantially smaller than the region bounded by the NAT existence temperature threshold. Temperature-time histories of air parcels demonstrate that the depletion is more clearly correlated with prior exposure to temperatures a few kelvin above the frost-point. From the combined data we infer the presence of large-size NAT particles with effective radii >5-7 ?m and low NAT number densities <1 × 10-3 cm-3. This denitrification event is observed close to the pole in the Antarctic vortex before synoptic temperatures first fall below the ice frost point and before the widespread occurrence of large-scale NAT PSCs. An episode of mountain wave activity detected by AIRS on 28 May 2008 led to wave-ice formation in the rapid cooling phases over the Antarctic Peninsula and Ellsworth Mountains, seeding an outbreak of NAT PSCs that were detected by CALIOP and MIPAS. The NAT clouds formed at altitudes of 18-26 km in a polar freezing belt and appear to be composed of relatively small particles with estimated effective radii of around 1 ?m and high NAT number densities >0.2 cm-3. This NAT outbreak is similar to an event previously reported from MIPAS observations in mid-June 2003.

  3. Ab initio molecular dynamics study on the initial chemical events in nitramines: thermal decomposition of CL-20.

    PubMed

    Isayev, Olexandr; Gorb, Leonid; Qasim, Mo; Leszczynski, Jerzy

    2008-09-01

    CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane or HNIW) is a high-energy nitramine explosive. To improve atomistic understanding of the thermal decomposition of CL-20 gas and solid phases, we performed a series of ab initio molecular dynamics simulations. We found that during unimolecular decomposition, unlike other nitramines (e.g., RDX, HMX), CL-20 has only one distinct initial reaction channelhomolysis of the N-NO2 bond. We did not observe any HONO elimination reaction during unimolecular decomposition, whereas the ring-breaking reaction was followed by NO 2 fission. Therefore, in spite of limited sampling, that provides a mostly qualitative picture, we proposed here a scheme of unimolecular decomposition of CL-20. The averaged product population over all trajectories was estimated at four HCN, two to four NO2, two to four NO, one CO, and one OH molecule per one CL-20 molecule. Our simulations provide a detailed description of the chemical processes in the initial stages of thermal decomposition of condensed CL-20, allowing elucidation of key features of such processes as composition of primary reaction products, reaction timing, and Arrhenius behavior of the system. The primary reactions leading to NO2, NO, N 2O, and N2 occur at very early stages. We also estimated potential activation barriers for the formation of NO2, which essentially determines overall decomposition kinetics and effective rate constants for NO2 and N2. The calculated solid-phase decomposition pathways correlate with available condensed-phase experimental data. PMID:18686996

  4. Isothermal decomposition of gamma-irradiated dysprosium acetate

    NASA Astrophysics Data System (ADS)

    Mahfouz, R. M.; Al-Shehri, S. M.; Monshi, M. A. S.; Abd El-Salam, N. M.

    Isothermal decomposition of un-irradiated and pre-gamma-irradiated dysprosium acetate [Dy(CH3COO)(3)] has been investigated at different temperatures between 603-623 K. Irradiation was observed to enhance the rate of decomposition without modifying the mechanism of the thermal decomposition. Thermal decomposition of dysposium acetate is shown to proceed by a nucleation and growth mechanism (Avarmi-Erofe'ev equation) both for un-irradiated and pre-gamma-irradiated samples. The enhancement of the decomposition was found to increase with an increase in the gamma-ray dose applied to the sample and may be attributed to an increase in point defects and formation of additional nucleation centers generated in the host lattice. Thermodynamic values of the main decomposition process were calculated and evaluated.

  5. A-train CALIOP and MLS observations of early winter antarctic polar stratospheric clouds and nitric acid in 2008

    NASA Astrophysics Data System (ADS)

    Lambert, A.; Santee, M. L.; Wu, D. L.; Chae, J. H.

    2011-10-01

    A-train Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Microwave Limb Sounder (MLS) observations are used to investigate the development of polar stratospheric clouds (PSCs) and the gas phase nitric acid distribution in the early 2008 Antarctic winter. Observational evidence of gravity-wave activity is provided by Atmospheric Infrared Sounder (AIRS) radiances and infrared spectroscopic detection of nitric acid trihydrate (NAT) in PSCs is obtained from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). Goddard Earth Observing System Data Assimilation System (GEOS-5 DAS) analyses are used to derive Lagrangian trajectories and to determine temperature-time histories of air parcels. We use CALIOP backscatter and depolarization measurements to classify PSCs and the MLS measurements to determine the corresponding gas phase HNO3 as a function of temperature. For liquid PSCs the uptake of HNO3 follows the theoretical equilibrium curve for supercooled ternary solutions (STS), but at temperatures about 1 K lower as determined from GEOS-5. In the presence of solid phase PSCs, above the ice frost-point, the HNO3 depletion occurs over a wider range of temperatures (+2 to -7 K) distributed about the NAT equilibrium curve. Rapid gas phase HNO3 depletion is first seen by MLS from from 23-25 May 2008, consisting of a decrease in the volume mixing ratio (parts per billion by volume) from 14 ppbv to 7 ppbv on the 46-32 hPa (hectopascal) pressure levels and accompanied by a 2-3 ppbv increase by renitrification at the 68 hPa pressure level. Temperature-time histories of air parcels demonstrate that the depleted HNO3 region is more clearly correlated with prior low temperature exposure of a few kelvin above the frost-point than with either the region bounded by the NAT existence temperature threshold or the region of minimum temperatures. From the combined data we infer the presence of large-size NAT particles with effective radii >5-7 ?m and low NAT number densities <1×10-3 cm-3. This denitrification event is observed close to the pole in the Antarctic vortex before synoptic temperatures first fall below the ice frost point and before the widespread occurrence of large-scale NAT PSCs at altitudes 18-26 km in a polar freezing belt. The NAT outbreak is similar to an event previously reported from MIPAS observations in mid-June 2003 and is again linked to NAT formation via ice-seeding following an episode of mountain wave activity detected by AIRS. Subsequent wave-ice formation in the rapid cooling phases over the Antarctic Peninsula and Ellsworth Mountains is detected here by CALIOP and MIPAS. The NAT clouds appear to be composed of relatively small particles with estimated effective radii of around 1 ?m and high NAT number densities >0.2 cm-3.

  6. The Association between Parent Early Adult Drug Use Disorder and Later Observed Parenting Practices and Child Behavior Problems: Testing Alternate Models

    ERIC Educational Resources Information Center

    Bailey, Jennifer A.; Hill, Karl G.; Guttmannova, Katarina; Oesterle, Sabrina; Hawkins, J. David; Catalano, Richard F.; McMahon, Robert J.

    2013-01-01

    This study tested the association between parent illicit drug use disorder (DUD) in early adulthood and observed parenting practices at ages 27-28 and examined the following 3 theoretically derived models explaining this link: (a) a disrupted parent adult functioning model,(b) a preexisting parent personality factor model, and (c) a disrupted…

  7. Social-Emotional Well-Being and Resilience of Children in Early Childhood Settings--PERIK: An Empirically Based Observation Scale for Practitioners

    ERIC Educational Resources Information Center

    Mayr, Toni; Ulich, Michaela

    2009-01-01

    Compared with the traditional focus on developmental problems, research on positive development is relatively new. Empirical research in children's well-being has been scarce. The aim of this study was to develop a theoretically and empirically based instrument for practitioners to observe and assess preschool children's well-being in early…

  8. Symptom Clusters during the Late Reproductive Stage through the Early Postmenopause: Observations from the Seattle Midlife Women’s Health Study

    PubMed Central

    Cray, Lori A.; Woods, Nancy Fugate; Herting, Jerald R.; Mitchell, Ellen Sullivan

    2012-01-01

    Objective Identify symptom clusters that characterize women’s experiences through the late reproductive stage, the menopausal transition and early postmenopause; and explore the influence of the menopausal transition stages and early postmenopause, compared to the late reproductive stage, on the clusters of symptoms women experience. Methods Participants from the Seattle Midlife Women’s Health Study whose symptom calendars were staged for menopausal transition provided data for a total of 6857 occasions. Multilevel latent class analysis was used to identify classes using scores for hot flashes and symptom factors (sleep, cognitive, mood, pain, tension). Results Class 1 included observations of low severity levels for all symptoms, whereas class 2 included low severity hot flashes and moderate severity levels for all other symptom factors. Class 3 included high severity hot flashes with lower severity levels of all other symptom factors. During the early and late menopausal transitions stages and early postmenopause, the likelihood of being in class 3 was significantly greater than being in class 1 relative to the late reproductive stage. There were no significant effects of menopausal transition stages on the likelihood of being in class 2. Conclusions This effort is the first to examine latent classes or clusters of symptoms over the prolonged period from late reproductive stage through early postmenopause. As such, the data contribute to understanding of symptom experiences beyond our early efforts to characterize the late menopausal transition stage. PMID:22643229

  9. Nuclear spinodal decomposition

    NASA Astrophysics Data System (ADS)

    López, Jorge A.; Lübeck, Georg

    1989-03-01

    We use computer simulations to study nuclear fragmentation as expected to occur in heavy ion reaction. Using integral equation techniques and molecular dynamics calculations we first find a potential with an equation of state resembling that of hot and dense nuclear matter. We then use this potential to study the disassembly of two dimensional classical drops. Along the lines of Cahn's theory of spinodal decomposition we calculate the structure factor of the system and extract information about the development of density fluctuations during the breakup. We find isothermal spinodal decomposition to play the dominant role in the breakup. Nucleation of bubbles in the two phase region and adiabatic spinodal decomposition were found not to contribute to the fragment production. Strong density fluctuations were detected in disassemblies crossing the critical point. Present address: Fred Hutchinson Cancer Research Center, 1124 Columbia St., Seatle, WA 98104, USA.

  10. Perturbative method for generalized spectral decompositions

    E-print Network

    Roberto Laura; Mario Castagnino; Rodolfo M. Id Betan

    2000-05-17

    Imposing analytic properties to states and observables we construct a perturbative method to obtain a generalized biorthogonal system of eigenvalues and eigenvectors for quantum unstable systems. A decay process can be described using this generalized spectral decomposition, and the final generalized state is obtained.

  11. Segre decomposition of spacetimes

    E-print Network

    Jose M M Senovilla; Raul Vera

    1999-02-11

    Following a recent work in which it is shown that a spacetime admitting Lie-group actions may be disjointly decomposed into a a closed subset with no interior plus a dense finite union of open sets in each of which the character and dimension of the group orbits as well as the Petrov type are constant, the aim of this work is to include the Segre types of the Ricci tensor (and hence of the Einstein tensor) into the decomposition. We also show how this type of decomposition can be carried out for any type of property of the spacetime depending on the existence of a continuous endomorphism.

  12. Tensor Decompositions: Exploiting Structure in Observed Correlations

    E-print Network

    Yang, Junfeng

    state active mixture of Gaussians, single topic per document Independent Component Analysis Blind source separation audio signal has different speakers talking independent factors What about the middle ground? S. M

  13. ChemTeacher: Decomposition Reactions

    NSDL National Science Digital Library

    2011-01-01

    ChemTeacher compiles background information, videos, articles, demonstrations, worksheets and activities for high school teachers to use in their classrooms. The Decomposition Reactions page includes resources for teaching students about identifying and predicting decomposition reactions.

  14. Hydrazine decomposition and other reactions

    NASA Technical Reports Server (NTRS)

    Armstrong, Warren E. (Inventor); La France, Donald S. (Inventor); Voge, Hervey H. (Inventor)

    1978-01-01

    This invention relates to the catalytic decomposition of hydrazine, catalysts useful for this decomposition and other reactions, and to reactions in hydrogen atmospheres generally using carbon-containing catalysts.

  15. Rainbow decompositions Raphael Yuster

    E-print Network

    Yuster, Raphael

    Rainbow decompositions Raphael Yuster Department of Mathematics University of Haifa Haifa 31905, Israel Abstract A rainbow coloring of a graph is a coloring of the edges with distinct colors. We prove-disjoint rainbow copies of Kk. Our proof uses, as a main ingredient, a double application of the probabilistic

  16. Decomposition of geometric perturbations

    E-print Network

    Roman V. Buniy; Thomas W. Kephart

    2008-11-12

    For an infinitesimal deformation of a Riemannian manifold, we prove that the scalar, vector, and tensor modes in decompositions of perturbations of the metric tensor, the scalar curvature, the Ricci tensor, and the Einstein tensor decouple if and only if the manifold is Einstein. Four-dimensional space-time satisfying the condition of the theorem is homogeneous and isotropic. Cosmological applications are discussed.

  17. Early-Career EBD Teacher Knowledge, Ratings of Competency Importance, and Observed Use of Instruction and Management Competencies

    ERIC Educational Resources Information Center

    Anderson, Lori F.; Hendrickson, Jo M.

    2007-01-01

    The empirical, conceptual, and theoretical knowledge of early-career EBD teachers was assessed two years after student teaching and compared to their ratings of the importance of specific instruction and classroom management competencies as well as to their application of those competencies. Twelve teachers, six elementary and six secondary, with…

  18. Extension to the North Atlantic oscillation using early instrumental pressure observations from Gibraltar and south-west Iceland

    Microsoft Academic Search

    P. D. Jones; T. Jonsson; D. Wheeler

    1997-01-01

    Early instrumental pressure measurements from Gibraltar and the Reykjavik area of Iceland have been used to extend to 1821 the homogeneous pressure series at the two locations. In winter the two sites are located close to the centres of action that comprise the North Atlantic Oscillation (NAO). The extended winter half-year record of the NAO enables recent changes in the

  19. Decomposition of the Inorganic Cyanamides

    Microsoft Academic Search

    M. J. Sole; A. D. Yoffe

    1964-01-01

    A detailed study has been made of the thermal decomposition of silver cyanamide crystals and powder, and also on the effect of pre-irradiation with gamma-rays, neutrons and fission fragments. The decomposition is a complex process, and involves the formation of an intermediate. The physical properties and decomposition behaviour of silver cyanamide show that it is a covalent solid, and it

  20. MODULAR DECOMPOSITION OF BOOLEAN FUNCTIONS

    Microsoft Academic Search

    2002-01-01

    Modular decomposition is a thoroughly investigated topic in many areas such as switching theory, reliability theory, game theory and graph theory. Most appli- cations can be formulated in the framework of Boolean functions. In this paper we give a uni_ed treatment of modular decomposition of Boolean functions based on the idea of generalized Shannon decomposition. Furthermore, we discuss some new

  1. Modular Decomposition of Boolean Functions

    Microsoft Academic Search

    Cor Bioch

    2002-01-01

    Modular decomposition is a thoroughly investigated topic in many areas suchas switching theory, reliability theory, game theory and graph theory. Most appli-cations can be formulated in the framework of Boolean functions. In this paperwe give a uni_ed treatment of modular decomposition of Boolean functions basedon the idea of generalized Shannon decomposition. Furthermore, we discuss somenew results on the complexity of

  2. The early stage of formation of self-organized nanocolumns in thin films: Monte Carlo simulations versus atomic-scale observations in Ge-Mn

    SciTech Connect

    Mouton, I.; Talbot, E., E-mail: etienne.talbot@univ-rouen.fr; Pareige, C.; Lardé, R.; Blavette, D. [Groupe de Physique des Matériaux (GPM) UMR 6634, Normandie Université, Université et INSA de Rouen - CNRS, Av. de l'Université, BP 12, 76801 Saint Etienne du Rouvray (France)

    2014-02-07

    Formation kinetics of self-organized nanocolumns during epitaxial growth of a thin film composed of immiscible elements (A,B) has been investigated using Kinetic Monte Carlo simulations. Simulated nanostructures show a good agreement with those observed in Ge-Mn using Atom Probe Tomography and Transmission Electron Microscopy. Self organisation is observed although the rigid lattice simulations used do not account for misfit elastic strain. Simulations reveal that the final nanostructure, in term of number density and diameter of nanocolumns, is controlled by the early stages of growth of the film. The influence of both growth temperature and solute concentration on the nanostructure features is discussed in details.

  3. Nitrosonium-Catalyzed Decomposition of S-Nitrosothiols in Solution

    PubMed Central

    Zhao, Yi-Lei; McCarren, Patrick R.; Houk, K. N.; Choi, Bo Yoon; Toone, Eric J.

    2008-01-01

    The decomposition of S-nitrosothiols (RSNO) in solution under oxidative conditions is significantly faster than can be accounted for by homolysis of the S-N bond. Here we propose a cationic chain mechanism in which nitrosylation of nitrosothiol produces a nitrosylated cation that, in turn, reacts with a second nitrosothiol to produce disulfide and the NO dimer. Nitrosylated dimer acts as a source of nitrosonium for nitrosothiol nitrosylation, completing the catalytic cycle. The mechanism accounts for several unexplained facets of nitrosothiol chemistry in solution, including the observation that the decomposition of an RSNO is accelerated by O2, mixtures of O2 and NO, and other oxidants, that decomposition is inhibited by thiols and other antioxidants, that decomposition is dependent on sulfur substitution, and that decomposition often shows non-integral kinetic orders. PMID:16076198

  4. Litter evenness influences short-term peatland decomposition processes.

    PubMed

    Ward, Susan E; Ostle, Nick J; McNamara, Niall P; Bardgett, Richard D

    2010-10-01

    There is concern that changes in climate and land use could increase rates of decomposition in peatlands, leading to release of stored C to the atmosphere. Rates of decomposition are driven by abiotic factors such as temperature and moisture, but also by biotic factors such as changes in litter quality resulting from vegetation change. While effects of litter species identity and diversity on decomposition processes are well studied, the impact of changes in relative abundance (evenness) of species has received less attention. In this study we investigated effects of changes in short-term peatland plant species evenness on decomposition in mixed litter assemblages, measured as litter weight loss, respired CO(2) and leachate C and N. We found that over the 307-day incubation period, higher levels of species evenness increased rates of decomposition in mixed litters, measured as weight loss and leachate dissolved organic N. We also found that the identity of the dominant species influenced rates of decomposition, measured as weight loss, CO(2) flux and leachate N. Greatest rates of decomposition were when the dwarf shrub Calluna vulgaris dominated litter mixtures, and lowest rates when the bryophyte Pleurozium schreberi dominated. Interactions between evenness and dominant species identity were also detected for litter weight loss and leachate N. In addition, positive non-additive effects of mixing litter were observed for litter weight loss. Our findings highlight the importance of changes in the evenness of plant community composition for short-term decomposition processes in UK peatlands. PMID:20431923

  5. Thermal decomposition of borax

    Microsoft Academic Search

    I. Waclawska

    1995-01-01

    Thermal decomposition of borax has been researched by thermal, XRD and FTIR methods as well as SEM microscopy. Study have\\u000a revealed that it proceeds according to the mechanism of internal reactions in the structure of the precursor as a medium.\\u000a \\u000a The following stages of the process have been distinguished: (1) dehydration, (2) internal structure reconstitution—formation\\u000a of tincalconite, (3) amorphization of

  6. Early Structural Anomalies Observed by High-Resolution Imaging in Two Related Cases of Autosomal-Dominant Retinitis Pigmentosa

    PubMed Central

    Park, Sung Pyo; Lee, Winston; Bae, Eun Jin; Greenstein, Vivianne; Sin, Bum Ho; Chang, Stanley; Tsang, Stephen H.

    2015-01-01

    The authors report the use of adaptive-optics scanning laser ophthalmoscopy (AO-SLO) to investigate RHO, D190N autosomal-dominant retinitis pigmentosa in two siblings (11 and 16 years old, respectively). Each patient exhibited distinct hyperautofluorescence patterns in which the outer borders corresponded to inner segment ellipsoid band disruption. Areas within the hyperautofluorescence patterns exhibited normal photoreceptor outer segments and retinal pigment epithelium. However, AO-SLO imaging revealed noticeable spacing irregularities in the cone mosaic. AO-SLO allows researchers to characterize retinal structural abnormalities with precision so that early structural changes in retinitis pigmentosa can be identified and reconciled with genetic findings. PMID:25215869

  7. MASTER Early Optical Polarization Observations of Black Hole Candidate V404 Cyg and 10 Minutes Polarization Variability Detection.

    NASA Astrophysics Data System (ADS)

    Lipunov, V.; Rebolo, R.; Gorbovskoy, E.; Serra-Ricart, M.; Gress, O.; Lodieu, N.; Israelian, G.; Suarez-Andres, L.; Kornilov, V.; Tiurina, N.; Balanutsa, P.; Popova, E.; Chazov, V.; Krushinsky, V.; Budnev, N.; Ivanov, K.; Tlatov, A.; Senik, V.; Dormidontov, D.; Buckley, D.; Potter, S.; Kniazev, A.; Kotze, M.; Sergienko, Yu.; Yurkov, V.; Gabovich, A.

    2015-06-01

    MASTER Robotic Net (MASTER-Net: http://observ.pereplet.ru) was started observation of one of the best Black Hole candidate - V404 Cyg by GCN Swift trigger N 643949 at 2015-06-15 18:34:09 UT (Barthelmy et. al GCN #17929 ) i.e. 22 sec after notice time and 150 sec after trigger time.

  8. Spot the difference. Impact of different selection criteria on early-type galaxies observed properties in zCOSMOS 20-k sample

    E-print Network

    Moresco, M; Cimatti, A; Zamorani, G; Bolzonella, M; Lamareille, F; Mignoli, M; Zucca, E; Lilly, S J; Carollo, C M; Contini, T; Kneib, J -P; Fevre, O Le; Mainieri, V; Renzini, A; Scodeggio, M; Bardelli, S; Bongiorno, A; Caputi, K; Cucciati, O; de la Torre, S; de Ravel, L; Franzetti, P; Garilli, B; Iovino, A; Kampczyk, P; Knobel, C; Kovac, K; Borgne, J -F Le; Brun, V Le; Maier, C; Pello', R; Peng, Y; Perez-Montero, E; Presotto, V; Silverman, J D; Tanaka, M; Tasca, L; Tresse, L; Vergani, D; Barnes, L; Bordoloi, R; Cappi, A; Diener, C; Koekemoer, A M; Floch, E Le; Lopez-Sanjuan, C; McCracken, H J; Nair, P; Oesch, P; Scarlata, C; Scoville, N; Welikala, N

    2013-01-01

    We present the analysis of photometric, spectroscopic and morphological properties for differently selected samples of early-type galaxies up to z=1 extracted from the zCOSMOS-20k spectroscopic survey. This analysis intends to explore the dependence of galaxy properties on the selection criterion adopted, to study the degree of contamination due to blue/star-forming/non-passive outliers, and to provide a comparison between different commonly used selection criteria. We extracted from the zCOSMOS-20k catalog 6 different samples of early-type galaxies based on morphology, optical colors, specific star formation rate, a best-fit to the observed spectral energy distribution, and a criterion combining morphological, spectroscopic and photometric informations. The "morphological" sample has the higher percentage of contamination in colors, specific star formation rate and presence of emission lines, while the "pure passive" sample is the purest, with properties mostly compatible with no star formation activity; how...

  9. Early Metacarpal Bone Mineral Density Loss Using Digital X-Ray Radiogrammetry and 3-Tesla Wrist MRI in Established Rheumatoid Arthritis: A Longitudinal One-Year Observational Study

    PubMed Central

    Algulin, Jakob; Mangat, Pamela; Lim, Adrian K. P.; Satchithananda, Keshthra; Hajnal, Joseph V.; Taylor, Peter C.

    2015-01-01

    Objectives. Early change in rheumatoid arthritis (RA) is characterised by periarticular osteopenia. We investigated the relationship of early metacarpal digital X-ray radiogrammetry bone mineral density (DXR-BMD) change rate (RC-BMD, mg/cm2/month) to longitudinal changes in hand and feet radiographic and wrist MRI scores over 1 year. Materials and Methods. 10 RA patients completed the study and had wrist 3T-MRI and hand and feet X-rays at various time points over 1 year. MRI was scored by RAMRIS, X-ray was done by van der Heijde modified Sharp scoring, and RC-BMD was analysed using dxr-online. Results. There was good correlation amongst the two scorers for MRI measures and ICC for erosions: 0.984, BME: 0.943, and synovitis: 0.657. Strong relationships were observed between RC-BMD at 12-week and 1-year change in wrist marrow oedema (BME) (r = 0.78, P = 0.035) but not with erosion, synovitis, or radiographic scores. Conclusion. Early RC-BMD correlates with 1-year wrist BME change, which is a known predictor of future erosion and joint damage. However, in our pilot study, early RC-BMD did not show relationships to MRI erosion or radiographic changes over 1 year. This may reflect a slower kinetic in the appearance of MRI/radiographic erosions, generating the hypothesis that RC-BMD may be a more sensitive and early structural prognostic marker in RA follow-up. PMID:25785197

  10. The Association between Parent Early Adult Drug Use Disorder and Later Observed Parenting Practices and Child Behavior Problems: Testing Alternate Models

    PubMed Central

    Bailey, Jennifer A.; Hill, Karl G.; Guttmannova, Katarina; Oesterle, Sabrina; Hawkins, J. David; Catalano, Richard F.; McMahon, Robert J.

    2012-01-01

    This study tested the association between parent illicit drug use disorder (DUD) in early adulthood and observed parenting practices at ages 27 – 28 and examined the following three, theoretically-derived models explaining this link: a) a disrupted parent adult functioning model, b) a pre-existing parent personality factor model, c) a disrupted adolescent family process model. Associations between study variables and child externalizing problems also were examined. Longitudinal data linking two generations were drawn from the Seattle Social Development Project (SSDP) and The SSDP Intergenerational Project (TIP), and included 167 parents and their 2- to 8-year-old child. Path modeling revealed that parent DUD in early adulthood predicted later observed low-skilled parenting, which was related to child externalizing problems. The pre-existing parent personality factor model was supported. Parent negative emotionality accounted for the association between parent early adult DUD and later parenting practices. Parent negative emotionality also was related directly to child externalizing behavior. Limited support for the disrupted transition to adulthood model was found. The disrupted adolescent family process model was not supported. Results suggest that problem drug use that occurs early in adulthood may affect later parenting skills, independent of subsequent parent drug use. Findings highlight the importance of parent negative emotionality in influencing their own problem behavior, their interactions with their child, and their child’s problem behavior. Prevention and treatment programs targeting young adult substance use, poor parenting practices, and child behavior problems should address parent personality factors that may contribute to these behaviors. PMID:22799581

  11. Slewing Mirror Telescope optics for the early observation of UV/optical photons from Gamma-Ray Bursts.

    PubMed

    Jeong, S; Nam, J W; Ahn, K B; Park, I H; Kim, S W; Lee, J; Lim, H; Brandt, S; Budtz-Jørgensen, C; Castro-Tirado, A J; Chen, P; Cho, M H; Choi, J N; Grossan, B; Huang, M A; Jung, A; Kim, J E; Kim, M B; Kim, Y W; Linder, E V; Min, K W; Na, G W; Panasyuk, M I; Ripa, J; Reglero, V; Smoot, G F; Suh, J E; Svertilov, S; Vedenkin, N; Yashin, I

    2013-01-28

    We report on design, manufacture, and testing of a Slewing Mirror Telescope (SMT), the first of its kind and a part of Ultra-Fast Flash Observatory-pathfinder (UFFO-p) for space-based prompt measurement of early UV/optical light curves from Gamma-Ray Bursts (GRBs). Using a fast slewing mirror of 150 mm diameter mounted on a 2 axis gimbal stage, SMT can deliver the images of GRB optical counterparts to the intensified CCD detector within 1.5~1.8 s over ± 35 degrees in the slewing field of view. Its Ritchey-Chrétien telescope of 100 mm diameter provides a 17 × 17 arcmin² instantaneous field of view. Technical details of design, construction, the laboratory performance tests in space environments for this unique SMT are described in conjunction with the plan for in-orbit operation onboard the Lomonosov satellite in 2013. PMID:23389206

  12. High variability in glucocorticoid starting doses in patients with rheumatoid arthritis: observational data from an early arthritis cohort.

    PubMed

    Albrecht, Katinka; Callhoff, Johanna; Schneider, Matthias; Zink, Angela

    2015-08-01

    To evaluate initial glucocorticoid (GC) therapy in patients with rheumatoid arthritis (RA). Six hundred sixty-nine patients with early RA were followed for 2 years in the multicenter "Course And Prognosis of Early Arthritis" cohort. Treatment was applied according to routine care. Assessments included disease activity (DAS28), disability Hannover Functional Status Questionnaire (FFbH), and treatment details. Mixed models, ANCOVA, and logistic regression models were used for statistical analysis. In total, 518 patients (77 %) received oral GCs at baseline; 20 % received a low dose (<7.5 mg prednisolone/day), 22 % received a moderate (7.5-19 mg), and 35 % received a high dose (?20 mg). In a multivariate logistic regression analysis, higher DAS28 values (OR 1.3) were associated with the use of higher GC doses at baseline (p < 0.001). After adjusting for age, sex, and baseline DAS28 and DMARDs, the patients who started with high-dose GCs had a greater improvement in DAS28 (month 3) and FFbH (month 6, p < 0.001 each). At 2 years, the mean DAS28 remission rates and FFbH values were similar. In all GC groups, the mean dose was tapered to 4 mg/day within 6 months. The reported comorbidities were not increased in patients with high-dose GC therapy. Starting treatment with high-dose GCs led to a better clinical response within 3 to 6 months compared to starting patients on lower dosages. Irrespective of the starting approach, rheumatologists tapered GCs down to a low dose within 6 months. With this strategy, clinical outcomes at 2 years did not differ relevantly. PMID:25663291

  13. On fault tolerant matrix decomposition

    Microsoft Academic Search

    Patrick Fitzpatrick

    1994-01-01

    We present a fault tolerant algorithm for matrix factorization in the presence of multiple hardware faults which can be used for solving the linear systemAx=b without determining the correctZU decomposition ofA. HereZ is eitherL for ordinary Gaussian decomposition with partial pivoting,X for pairwise or neighbor pivoting (motivated by the Gentleman-Kung systolic array structure), orQ for the usualQR decomposition. Our algorithm

  14. Hydraulic redistribution may stimulate decomposition

    Microsoft Academic Search

    Zachary T. Aanderud; James H. Richards

    2009-01-01

    Roots influence root litter decomposition through multiple belowground processes. Hydraulic lift or redistribution (HR) by\\u000a plants is one such process that creates diel drying–rewetting cycles in soil. However, it is unclear if this phenomenon influences\\u000a decomposition. Since decomposition in deserts is constrained by low soil moisture and is stimulated when dry soils are rewetted,\\u000a we hypothesized that diel drying–rewetting, via

  15. Initiation and Early Evolution of the Coronal Mass Ejection on 2009 May 13 from Extreme-ultraviolet and White-light Observations

    NASA Astrophysics Data System (ADS)

    Reva, A. A.; Ulyanov, A. S.; Bogachev, S. A.; Kuzin, S. V.

    2014-10-01

    We present the results of the observations of a coronal mass ejection (CME) that occurred on 2009 May 13. The most important feature of these observations is that the CME was observed from the very early stage (the solar surface) up to a distance of 15 solar radii (R ?). Below 2 R ?, we used the data from the TESIS extreme-ultraviolet telescopes obtained in the Fe 171 Å and He 304 Å lines, and above 2 R ?, we used the observations of the LASCO C2 and C3 coronagraphs. The CME was formed at a distance of 0.2-0.5R ? from the Sun's surface as a U-shaped structure, which was observed both in the 171 Å images and in the white light. Observations in the He 304 Å line showed that the CME was associated with an erupting prominence, which was not located above—as the standard model predicts—but rather in the lowest part of the U-shaped structure close to the magnetic X point. The prominence location can be explained with the CME breakout model. Estimates showed that CME mass increased with time. The CME trajectory was curved—its heliolatitude decreased with time. The CME started at a latitude of 50° and reached the ecliptic plane at distances of 2.5 R ?. The CME kinematics can be divided into three phases: initial acceleration, main acceleration, and propagation with constant velocity. After the CME, onset GOES registered a sub-A-class flare.

  16. Mode decomposition evolution equations.

    PubMed

    Wang, Yang; Wei, Guo-Wei; Yang, Siyang

    2012-03-01

    Partial differential equation (PDE) based methods have become some of the most powerful tools for exploring the fundamental problems in signal processing, image processing, computer vision, machine vision and artificial intelligence in the past two decades. The advantages of PDE based approaches are that they can be made fully automatic, robust for the analysis of images, videos and high dimensional data. A fundamental question is whether one can use PDEs to perform all the basic tasks in the image processing. If one can devise PDEs to perform full-scale mode decomposition for signals and images, the modes thus generated would be very useful for secondary processing to meet the needs in various types of signal and image processing. Despite of great progress in PDE based image analysis in the past two decades, the basic roles of PDEs in image/signal analysis are only limited to PDE based low-pass filters, and their applications to noise removal, edge detection, segmentation, etc. At present, it is not clear how to construct PDE based methods for full-scale mode decomposition. The above-mentioned limitation of most current PDE based image/signal processing methods is addressed in the proposed work, in which we introduce a family of mode decomposition evolution equations (MoDEEs) for a vast variety of applications. The MoDEEs are constructed as an extension of a PDE based high-pass filter (Europhys. Lett., 59(6): 814, 2002) by using arbitrarily high order PDE based low-pass filters introduced by Wei (IEEE Signal Process. Lett., 6(7): 165, 1999). The use of arbitrarily high order PDEs is essential to the frequency localization in the mode decomposition. Similar to the wavelet transform, the present MoDEEs have a controllable time-frequency localization and allow a perfect reconstruction of the original function. Therefore, the MoDEE operation is also called a PDE transform. However, modes generated from the present approach are in the spatial or time domain and can be easily used for secondary processing. Various simplifications of the proposed MoDEEs, including a linearized version, and an algebraic version, are discussed for computational convenience. The Fourier pseudospectral method, which is unconditionally stable for linearized the high order MoDEEs, is utilized in our computation. Validation is carried out to mode separation of high frequency adjacent modes. Applications are considered to signal and image denoising, image edge detection, feature extraction, enhancement etc. It is hoped that this work enhances the understanding of high order PDEs and yields robust and useful tools for image and signal analysis. PMID:22408289

  17. Hydrogen peroxide catalytic decomposition

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2010-01-01

    Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated through the use of concentrated hydrogen peroxide fed as a monopropellant into a catalyzed thruster assembly. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50%-70% by volume, and may be increased in concentration in a continuous process preceding decomposition in the thruster assembly. The exhaust of the thruster assembly, rich in hydroxyl and/or hydroperoxy radicals, may be fed into a stream containing oxidizable components, such as nitric oxide, to facilitate their oxidation.

  18. Decompositions of Grammar Constraints

    E-print Network

    Quimper, Claude-Guy

    2009-01-01

    A wide range of constraints can be compactly specified using automata or formal languages. In a sequence of recent papers, we have shown that an effective means to reason with such specifications is to decompose them into primitive constraints. We can then, for instance, use state of the art SAT solvers and profit from their advanced features like fast unit propagation, clause learning, and conflict-based search heuristics. This approach holds promise for solving combinatorial problems in scheduling, rostering, and configuration, as well as problems in more diverse areas like bioinformatics, software testing and natural language processing. In addition, decomposition may be an effective method to propagate other global constraints.

  19. Atmosphere-Ice-Ocean Interactions During Early Autumn Freeze-up: Boundary-Layer and Surface Observations from the ACSE Field Program

    NASA Astrophysics Data System (ADS)

    Persson, Ola; Brooks, Barbara; Tjernström, Michael; Sedlar, Joseph; Brooks, Ian; Shupe, Matthew; Björck, Göran; Prytherch, John; Salisbury, Dominic; Achtert, Peggy; Sotiropoulou, Georgia; Johnston, Paul; Wolfe, Daniel

    2015-04-01

    Surface energy fluxes are key to the annual summer melt and autumn freeze-up of Arctic sea ice, but are strongly modulated by atmospheric, ocean, and sea-ice processes. This paper will examine direct observations of energy fluxes during the onset of autumn freeze-up from the Arctic Clouds in Summer Experiment (ACSE), and place them in context of those from other observational campaigns. The ACSE field program obtained measurements of surface energy fluxes, boundary-layer structure, cloud macro- and microphysical structure, and upper-ocean thermal and salinity structure from pack-ice and open-water regions in the eastern Arctic from early July to early October 2014. Late August and September measurements showed periods of energy flux deficits, leading to freeze-up of sea ice and the ocean surface. The surface albedo and processes impacting the energy content of the upper ocean appear key to producing a temporal difference between the freeze-up of the sea ice and adjacent open water. While synoptic conditions, atmospheric advection, and the annual solar cycle have primary influence determining when energy fluxes are conducive for melt or freeze, mesoscale atmospheric phenomena unique to the ice edge region appear to also play a role. For instance, low-level jets were often observed near the ice edge during the latter part of ACSE, and may have enhanced the turbulent energy loss. In conjunction with observations of summer melt, these observations of the onset of freeze-up suggest scenarios of key atmospheric processes, including thermal advection on various scales, that are important for the annual evolution of melt and freeze-up.

  20. Quantification of carbonyls produced by the decomposition of hydroperoxides

    Microsoft Academic Search

    Bouali Saidia; Earl G. Hammond

    1989-01-01

    Carbonyls produced by the decomposition of cyclohexene hydroperoxide and various hydroperoxides of linoleic and linolenic\\u000a acids and their methyl esters were determined by gas chromatography of the 2,4,6-trichlorophenylhydrazones. The effect of\\u000a temperature, iron and copper ions, ethanol and several antioxidants on the rate of decomposition, the nature of the products\\u000a and their yield was observed. The hydroperoxides of methyl esters

  1. Observables and Invariance for Early Cognitive Vision G.J. Burghouts, J.M. Geusebroek, A.W.M. Smeulders

    E-print Network

    Geusebroek, Jan-Mark

    and Nascimento, 1994) of the visual stimulus. Sensing and representing the visual stimulus enables a visual, y, , t), (1) where () is a linear correlation operator and x, y, , t denote the scales. Together Visual Observables and Invariance Whereas receptive fields measure the 2-dimensional light field

  2. From Dogmatic Discussions to Observations and Planned Experiments: Some Examples from Early Aurora Borealis Research in Finland.

    ERIC Educational Resources Information Center

    Holmberg, Peter

    1996-01-01

    Traces the evolution of physics research methods in Finland from passive observations to planned experiments. Presents examples of planned experiments designed to solve particular problems with the goal of establishing a theory of the phenomenon under study. Contains 16 references. (JRH)

  3. From dogmatic discussions to observations and planned experiments: Some examples from early aurora borealis research in Finland

    Microsoft Academic Search

    Peter Holmberg

    1996-01-01

    With examples we show the change in physics research methods in Finland. From mere passive observations physics moved towards experiments and even planning special experiments to solve particular problems, the goal being to establish a theory of the phenomenon under study. In this way a fruitful interaction between experiment and theory emerged. Individual learning repeat this progression.

  4. Quality in Kindergarten Classrooms: Observational Evidence for the Need to Increase Children's Learning Opportunities in Early Education Classrooms

    ERIC Educational Resources Information Center

    La Paro, Karen M.; Hamre, Bridget K.; Locasale-Crouch, Jennifer; Pianta, Robert C.; Bryant, Donna; Early, Dianne; Clifford, Richard; Barbarin, Oscar; Howes, Carollee; Burchinal, Margaret

    2009-01-01

    Research Findings: Using observational data gathered in 730 kindergarten classrooms in 6 states, the present study focuses on the quality of children's learning opportunities in kindergarten classrooms. Findings show that overall, children experience moderate to low levels of quality in the areas of classroom organization and instructional support…

  5. When Does Atherosclerosis Become Irreversible? Chronological Change from an Early to an Advanced Atherosclerotic Lesion Observed by Angioscopy

    Microsoft Academic Search

    Norimichi Ikeda; Ryuzou Torii

    2005-01-01

    Quite a large number of studies on atherosclerosis have been published to date. However, no report on the development and irreversibility of lesions has been published so far. The authors conducted the following experiments to examine in vivo lesions under direct vision. Atherosclerotic lesions were created in 11 Japanese macaques, and progress of the lesions was observed under changing feeding

  6. Initiation and early evolution of a Coronal Mass Ejection on May 13, 2009 from EUV and white-light observations

    NASA Astrophysics Data System (ADS)

    Reva, Anton; Kuzin, Sergey; Bogachev, Sergey; Ulyanov, Artyom

    In this talk we present results of the observations of a CME, which occurred on May 13, 2009. The most important feature of these observations is that the CME was observed from the very beginning stage (the solar surface) up to the distance of 15 solar radii (R_?). Below 2 R_? we used the data from the TESIS EUV telescopes obtained in the Fe 171 Å and He 304 Å lines, and above 2 R_? we used the observations of the LASCO C2 and C3 coronagraphs. Using data of these three instruments, we have studied the evolution of the CME in details. The CME had a curved trajectory -- its helio-latitude decreased with time. The mass ejection originated at a latitudes of about 50(°) and reached the ecliptic plane at a distance of 2.5 R_? from the Sun’s center. The CME velocity and acceleration increased as the CME went away from the Sun. At the distance of 15 R_? from the Sun’s center the CME had a velocity of 250 km/s and an acceleration of 5 m/s(2) . The CME was not associated with a flare, and didn’t have an impulsive acceleration phase. The mass ejection had U-shaped structure which was observed both in the 171 Å images and in white-light. The CME was formed at a distance of about 0.2 -- 0.5 R_? from the Sun’s surface. Observations in the line 304 Å showed that the CME was associated with the erupting prominence, which was located in the lowest part of the U-shaped structure close to the X-point of the magnetic reconnection. The prominence disappeared at the height of 0.4 R_? above the solar limb. Some aspects of these observations can’t be explained in the standard CME model, which predicts that the prominence should be located inside the U-shaped structure, and the CME should be associated with a flare and have an impulsive acceleration phase.

  7. Early-type stars observed in the ESO UVES Paranal Observatory Project: I -- Interstellar Na I UV, Ti II and Ca II K observations

    E-print Network

    I. Hunter; J. V. Smoker; F. P. Keenan; C. Ledoux; E. Jehin; R. Cabanac; C. Melo; S. Bagnulo

    2006-01-17

    We present an analysis of interstellar Na I (lambda=3302.37\\AA, 3302.98\\AA), Ti II (lambda=3383.76\\AA) and Ca II K (lambda=3933.66\\AA) absorption features for 74 sightlines towards O- and B-type stars in the Galactic disc. The data were obtained from the UVES Paranal Observatory Project, at a spectral resolution of 3.75km/s and with mean signal to noise ratios per pixel of 260, 300 and 430 for the Na I, Ti II and Ca II observations, respectively. Interstellar features were detected in all but one of the Ti II sightlines and all of the Ca II sightlines. The dependence of the column density of these three species with distance, height relative to the Galactic plane, H I column density, reddening and depletion relative to the solar abundance has been investigated. We also examine the accuracy of using the Na I column density as an indicator of that for H I. In general we find similar strong correlations for both Ti and Ca, and weaker correlations for Na. Our results confirm the general belief that Ti and Ca occur in the same regions of the interstellar medium and also that the Ti II/Ca II ratio is constant over all parameters. We hence conclude that the absorption properties of Ti and Ca are essentially constant under the general interstellar medium conditions of the Galactic disc.

  8. Regional coordination of the ENERGY STAR{reg{underscore}sign} residential fixture program: Design, implementation, and early observations

    SciTech Connect

    Moore, J.; Gordon, L.; Latham, L.

    1998-07-01

    The Northwest Energy Efficiency Alliance and a group of California utilities are implementing a unique market transformation initiative to promote the use of energy-efficient residential light fixtures. This effort is based on the current ENERGY STAR{reg{underscore}sign} specification for residential fixtures, and combines manufacturer rebates with aggressive education and marketing efforts in order to stimulate increased sales of these products. The initiative was developed in 1997, and has been underway in Idaho, Montana, Oregon, Washington, and California since early 1998. Program efforts are designed to increase the availability of qualified fixtures in the retail and electric wholesale channels throughout the five-state area, and to stimulate direct sales to large homebuilders active in the region. An RFP process was used to select six lighting manufacturers, who are now eligible to receive rebate payments of $7 to $10 for each qualified fixture shipped during 1998. A similar process will be employed in late 1998 to select the eligible manufacturers for 1999. As of May 1998, participating manufacturers have shipped over 37,000 qualifying fixtures throughout the five states covered by the program, with most units being delivered to retain stores such as Home Depot, Home Base, Eagle Hardware and Garden, and Costco. These shipments represent 10% of the 1998 program goal.

  9. [Responses of litter decomposition and nutrient release to simulated nitrogen deposition in an evergreen broad-leaved forest in southwestern Sichuan].

    PubMed

    Song, Xue-Gui; Hu, Ting-Xing; Xian, Jun-Ren; Li, Wei; Wu, Wei-Guo; Xiao, Chun-Lian

    2007-10-01

    An in situ experiment was conducted in an evergreen broad-leaved forest in southwestern Sichuan to study the responses of litter decomposition and nutrient release to simulated nitrogen deposition. Four treatments were installed, i.e., null level (CK), low nitrogen level (LN, 50 kg N x hm(-2) x a(-1)), moderate nitrogen level (MN, 100 kg N x hm(-2) x a(-1)) and high nitrogen level (HN, 150 kg N x hm(-2) x a(-1)). The results showed that it would take 4.72-6.33 years to decompose 95% of litter mass, with the highest decomposition rate in CK and the lowest one in HN. After 365 days, the litter decomposition rate in N-amended treatments was lower than that in CK, but significant difference was only observed between HN and CK (P < 0.05). The remained C was higher, and the remained N and K were significantly higher in N-amended treatments than in CK (P < 0.05). The remained P was also higher in N-amended treatments than in CK, but significant difference was only observed between LN and CK (P < 0.05). Compared with CK, all N-amended treatments had a 3.9%-23.7% increase of litter C/N ratio. During litter decomposition, element N featured a pattern of accumulation at early stage and release later, while C, P and K released all the time. Nitrogen deposition inhibited both the nutrient release from the litter and the decomposition of its lignin and cellulose. The effects of nitrogen deposition on litter decomposition in the forest changed from positive to negative as time passed, and the negative effect could be strengthened with the increase of deposited nitrogen concentration. PMID:18163293

  10. Incidence of surgical site infection in the foot and ankle with early exposure and showering of surgical sites: a prospective observation.

    PubMed

    Feilmeier, Mindi; Dayton, Paul; Sedberry, Shelly; Reimer, Rachel A

    2014-01-01

    The incidence of postoperative surgical site infection (SSI) reported in the published data for foot and ankle surgery has been 1.0% to 5.3%. A variety of interventions have been used before, during, and after surgery to decrease the patient's risk of acquiring an infection at the surgical site. Foot and ankle surgeons often keep the incision site dry and covered until the sutures and pins have been removed, with the goal of preventing a SSI, despite the lack of available published evidence to support this practice. We undertook a prospective observation of 110 elective surgical patients to determine the rate of SSI when early surgical site exposure and showering were allowed. The risk factors for infection were recorded, and a series of logistic regression analyses was performed to determine the associations between the infection rate and early showering. The patients were evaluated at each postoperative appointment for signs of infection. For the present study, mild infection was defined as the subjective presence of erythema and/or swelling beyond that typically expected in the early postoperative period. These cases of presumed or mild SSI were managed with oral antibiotics until they had resolved. Major infection was defined as any infection altering the course of recovery or requiring admission or additional surgery. The overall infection rate was 4.5%, with all infections considered mild. Logistic regression analysis showed that none of the recorded risk factors significantly predicted infection. The results of the present study suggest that early daily showering of a surgical site after foot and ankle surgery will not be significantly associated with an increased risk of infection. PMID:24556483

  11. Hydrogen iodide decomposition

    DOEpatents

    O'Keefe, Dennis R. (San Diego, CA); Norman, John H. (San Diego, CA)

    1983-01-01

    Liquid hydrogen iodide is decomposed to form hydrogen and iodine in the presence of water using a soluble catalyst. Decomposition is carried out at a temperature between about 350.degree. K. and about 525.degree. K. and at a corresponding pressure between about 25 and about 300 atmospheres in the presence of an aqueous solution which acts as a carrier for the homogeneous catalyst. Various halides of the platinum group metals, particularly Pd, Rh and Pt, are used, particularly the chlorides and iodides which exhibit good solubility. After separation of the H.sub.2, the stream from the decomposer is countercurrently extracted with nearly dry HI to remove I.sub.2. The wet phase contains most of the catalyst and is recycled directly to the decomposition step. The catalyst in the remaining almost dry HI-I.sub.2 phase is then extracted into a wet phase which is also recycled. The catalyst-free HI-I.sub.2 phase is finally distilled to separate the HI and I.sub.2. The HI is recycled to the reactor; the I.sub.2 is returned to a reactor operating in accordance with the Bunsen equation to create more HI.

  12. VLT and NTT Observations of Two EIS Cluster Candidates. Detection of the Early-Type Galaxies Sequence at z~1

    E-print Network

    L. da Costa; M. Scodeggio; L. F. Olsen; M. Nonino; R. Rengelink; R. Bender; M. Franx; H. E. Jorgensen; A. Renzini; P. Rosati

    1999-01-19

    Optical data from the ESO VLT-UT1 Science Verification observations are combined with near-infrared data from SOFI at the NTT to obtain optical-infrared color-magnitude diagrams for the objects in the fields of two EIS cluster candidates. In both cases, evidence is found for a well-defined sequence of red galaxies that appear to be significantly more clustered than the background population. These results suggest that the two systems are real physical associations. The (R-Ks), (I-Ks) and (J-Ks) colors of the red sequences are used, in conjunction with similar data for spectroscopically confirmed clusters, to obtain redshift estimates of z ~ 0.9 and z ~ 1.0 for these two systems. These results make these EIS cluster candidates prime targets for follow-up spectroscopic observations to confirm their reality and to measure more accurately their redshift.

  13. Ensemble Empirical Mode Decomposition Analysis of EEG Data Collected during a Contour Integration Task

    PubMed Central

    Al-Subari, Karema; Al-Baddai, Saad; Tomé, Ana Maria; Volberg, Gregor; Hammwöhner, Rainer; Lang, Elmar W.

    2015-01-01

    We discuss a data-driven analysis of EEG data recorded during a combined EEG/fMRI study of visual processing during a contour integration task. The analysis is based on an ensemble empirical mode decomposition (EEMD) and discusses characteristic features of event related modes (ERMs) resulting from the decomposition. We identify clear differences in certain ERMs in response to contour vs noncontour Gabor stimuli mainly for response amplitudes peaking around 100 [ms] (called P100) and 200 [ms] (called N200) after stimulus onset, respectively. We observe early P100 and N200 responses at electrodes located in the occipital area of the brain, while late P100 and N200 responses appear at electrodes located in frontal brain areas. Signals at electrodes in central brain areas show bimodal early/late response signatures in certain ERMs. Head topographies clearly localize statistically significant response differences to both stimulus conditions. Our findings provide an independent proof of recent models which suggest that contour integration depends on distributed network activity within the brain. PMID:25910061

  14. UV-dropout Galaxies in the Goods-South Field from WFC3 Early Release Science Observations

    Microsoft Academic Search

    N. P. Hathi; R. E. Ryan Jr.; S. H. Cohen; H. Yan; R. A. Windhorst; P. J. McCarthy; R. W. O'Connell; A. M. Koekemoer; M. J. Rutkowski; B. Balick; H. E. Bond; D. Calzetti; M. J. Disney; M. A. Dopita; Jay A. Frogel; D. N. B. Hall; J. A. Holtzman; R. A. Kimble; F. Paresce; A. Saha; J. I. Silk; J. T. Trauger; A. R. Walker; B. C. Whitmore; E. T. Young

    2010-01-01

    We combine new high sensitivity ultraviolet (UV) imaging from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) with existing deep HST\\/Advanced Camera for Surveys optical images from the Great Observatories Origins Deep Survey (GOODS) program to identify UV-dropouts, which are Lyman break galaxy (LBG) candidates at z ~= 1-3. These new HST\\/WFC3 observations were taken over

  15. REAL-TIME HYDROMETEOROLOGICAL OBSERVATION NETWORKS - DEVELOPMENT POSSIBILITIES FOR THE EARLY WARNING SYSTEM OF THE MEKONG RIVER BASIN

    Microsoft Academic Search

    P. J. AIRAKSINEN; J. IKONEN; N. W. S. DEMETRIADES; H. POHJOLA

    Manual surface measurements have traditionally formed the basis for hydrometeorological observation networks. Although automation and real-time data communication has gradually increased, sufficient area coverage for minimizing uncertainties associated with spatial averaging of hydrometeorological variables is still relatively rare. The limited availability of real-time precipitation data for the Mekong River left bank (eastern) sub-basins of Lao PDR has been found to

  16. EARLY RADIO AND X-RAY OBSERVATIONS OF THE YOUNGEST NEARBY TYPE Ia SUPERNOVA PTF 11kly (SN 2011fe)

    SciTech Connect

    Horesh, Assaf; Kulkarni, S. R.; Carpenter, John; Kasliwal, Mansi M.; Ofek, Eran O. [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Fox, Derek B. [Astronomy and Astrophysics, Eberly College of Science, Pennsylvania State University, University Park, PA 16802 (United States); Quimby, Robert [IPMU, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa-shi, Chiba (Japan); Gal-Yam, Avishay [Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Cenko, S. Bradley [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); De Bruyn, A. G. [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, NL-7990 AA Dwingeloo (Netherlands); Kamble, Atish; Wijers, Ralph A. M. J. [Center for Gravitation and Cosmology, University of Wisconsin, Milwaukee, WI 53211 (United States); Van der Horst, Alexander J. [Universities Space Research Association, NSSTC, Huntsville, AL 35805 (United States); Kouveliotou, Chryssa [Space Science Office, VP-62, NASA-Marshall Space Flight Center, Huntsville, AL 35805 (United States); Podsiadlowski, Philipp; Sullivan, Mark; Maguire, Kate [Department of Physics (Astrophysics), University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Howell, D. Andrew [Las Cumbres Observatory Global Telescope Network, Santa Barbara, CA 93117 (United States); Nugent, Peter E. [Computational Cosmology Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Gehrels, Neil [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); and others

    2012-02-10

    On 2011 August 24 (UT) the Palomar Transient Factory (PTF) discovered PTF11kly (SN 2011fe), the youngest and most nearby Type Ia supernova (SN Ia) in decades. We followed this event up in the radio (centimeter and millimeter bands) and X-ray bands, starting about a day after the estimated explosion time. We present our analysis of the radio and X-ray observations, yielding the tightest constraints yet placed on the pre-explosion mass-loss rate from the progenitor system of this supernova. We find a robust limit of M-dot {approx}<10{sup -8}(w/100 km s{sup -1}) M{sub sun} yr{sup -1} from sensitive X-ray non-detections, as well as a similar limit from radio data, which depends, however, on assumptions about microphysical parameters. We discuss our results in the context of single-degenerate models for SNe Ia and find that our observations modestly disfavor symbiotic progenitor models involving a red giant donor, but cannot constrain systems accreting from main-sequence or sub-giant stars, including the popular supersoft channel. In view of the proximity of PTF11kly and the sensitivity of our prompt observations, we would have to wait for a long time (a decade or longer) in order to more meaningfully probe the circumstellar matter of SNe Ia.

  17. THE SIZE EVOLUTION OF PASSIVE GALAXIES: OBSERVATIONS FROM THE WIDE-FIELD CAMERA 3 EARLY RELEASE SCIENCE PROGRAM

    SciTech Connect

    Ryan, R. E. Jr. [Physics Department, University of California, Davis, CA 95616 (United States); McCarthy, P. J. [Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States); Cohen, S. H.; Rutkowski, M. J.; Mechtley, M. R.; Windhorst, R. A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Yan, H. [Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Hathi, N. P. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Koekemoer, A. M.; Bond, H. E.; Bushouse, H. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); O'Connell, R. W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Crockett, R. M. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Disney, M. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Dopita, M. A. [Research School of Astronomy and Astrophysics, The Australian National University, Weston Creek, ACT 2611 (Australia); Frogel, J. A. [Galaxies Unlimited, Lutherville, MD 21093 (United States); Hall, D. N. B. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Holtzman, J. A., E-mail: rryan@physics.ucdavis.edu [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); and others

    2012-04-10

    We present the size evolution of passively evolving galaxies at z {approx} 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates galaxies with little or no ongoing star formation at z {approx}> 1.5. We identify 30 galaxies in {approx}40 arcmin{sup 2} to H < 25 mag. By fitting the 10-band Hubble Space Telescope photometry from 0.22 {mu}m {approx}< {lambda}{sub obs} {approx}< 1.6 {mu}m with stellar population synthesis models, we simultaneously determine photometric redshift, stellar mass, and a bevy of other population parameters. Based on the six galaxies with published spectroscopic redshifts, we estimate a typical redshift uncertainty of {approx}0.033(1 + z). We determine effective radii from Sersic profile fits to the H-band image using an empirical point-spread function. By supplementing our data with published samples, we propose a mass-dependent size evolution model for passively evolving galaxies, where the most massive galaxies (M{sub *} {approx} 10{sup 11} M{sub Sun }) undergo the strongest evolution from z {approx} 2 to the present. Parameterizing the size evolution as (1 + z){sup -{alpha}}, we find a tentative scaling of {alpha} Almost-Equal-To (- 0.6 {+-} 0.7) + (0.9 {+-} 0.4)log (M{sub *}/10{sup 9} M{sub Sun }), where the relatively large uncertainties reflect the poor sampling in stellar mass due to the low numbers of high-redshift systems. We discuss the implications of this result for the redshift evolution of the M{sub *}-R{sub e} relation for red galaxies.

  18. The Size Evolution of Passive Galaxies: Observations From the Wide-Field Camera 3 Early Release Science Program

    NASA Technical Reports Server (NTRS)

    Ryan, R. E., Jr.; Mccarthy, P.J.; Cohen, S. H.; Yan, H.; Hathi, N. P.; Koekemoer, A. M.; Rutkowski, M. J.; Mechtley, M. R.; Windhorst, R. A.; O’Connell, R. W.; Balick, B.; Bond, H. E.; Bushouse, H.; Calzetti, D.; Crockett, R. M.; Disney, M.; Dopita, M. A.; Frogel, J. A.; Hall, D., N., B.; Holtzman, J. A.; Kaviraj, S.; Kimble, R. A.; MacKenty, J.; Trauger, J.; Young, E.

    2012-01-01

    We present the size evolution of passively evolving galaxies at z approximately 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates galaxies with little or no ongoing star formation at z greater than approximately 1.5. We identify 30 galaxies in approximately 40 arcmin(sup 2) to H less than 25 mag. By fitting the 10-band Hubble Space Telescope photometry from 0.22 micrometers less than approximately lambda (sub obs) 1.6 micrometers with stellar population synthesis models, we simultaneously determine photometric redshift, stellar mass, and a bevy of other population parameters. Based on the six galaxies with published spectroscopic redshifts, we estimate a typical redshift uncertainty of approximately 0.033(1+z).We determine effective radii from Sersic profile fits to the H-band image using an empirical point-spread function. By supplementing our data with published samples, we propose a mass-dependent size evolution model for passively evolving galaxies, where the most massive galaxies (M(sub *) approximately 10(sup 11) solar mass) undergo the strongest evolution from z approximately 2 to the present. Parameterizing the size evolution as (1 + z)(sup - alpha), we find a tentative scaling of alpha approximately equals (-0.6 plus or minus 0.7) + (0.9 plus or minus 0.4) log(M(sub *)/10(sup 9 solar mass), where the relatively large uncertainties reflect the poor sampling in stellar mass due to the low numbers of highredshift systems. We discuss the implications of this result for the redshift evolution of the M(sub *)-R(sub e) relation for red galaxies.

  19. Observational Evidence Against Mountain Wave Generation of Ice Clouds Leading to the Formation of NAT Clouds in Early December 1999 Within the Arctic Vortex

    NASA Astrophysics Data System (ADS)

    Pagan, K. L.; Tabazadeh, A.; Drdla, K.; Hervig, M. E.; Eckermann, S. D.; Browell, E. V.; Legg, M. J.; Foschi, P. G.

    2003-12-01

    A number of recently published papers suggest that mountain wave (or lee wave) activity in the stratosphere, producing temperatures below the ice frost point, may be the primary source of large NAT particles. We use thermal infrared radiance measurements from the Advanced Very High Resolution Radiometer (AVHRR) instruments on board the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites to map out regions of ice clouds produced by mountain wave cloud activity inside the Arctic vortex. Lidar observations from three DC-8 flights in early December 1999 show the presence of solid polar stratospheric cloud (PSC) Type Ia particles. By using back trajectories and superimposing the position maps on the AVHRR cloud imagery, we show that the observed solid Type Ia PSC particles could not have originated at locations of high mountain wave cloud activity. We also show that Mountain Wave Forecast Model 2.0 (MWFM-2) gridbox-averaged hemispheric hindcasts from the same time period are in agreement with the AVHRR data. Our results show that ice cloud formation in mountain wave clouds cannot explain how at least three large-scale solid HNO3 PSC structures were formed in the stratosphere in early December 1999.

  20. Direct Sum Decomposition of Groups

    ERIC Educational Resources Information Center

    Thaheem, A. B.

    2005-01-01

    Direct sum decomposition of Abelian groups appears in almost all textbooks on algebra for undergraduate students. This concept plays an important role in group theory. One simple example of this decomposition is obtained by using the kernel and range of a projection map on an Abelian group. The aim in this pedagogical note is to establish a direct…

  1. Sonochemical acceleration of persulfate decomposition

    Microsoft Academic Search

    Gareth J. Price; Andrew A. Clifton

    1996-01-01

    The decomposition kinetics of potassium persulfate in aqueous solution have been investigated using a radical trapping method. The use of ultrasound was found to markedly accelerate the decomposition so that the sonochemical process at 25°C occurs at the same rate as the purely thermal reaction at 55°C. The effect of ultrasound intensity has also been studied and can be used

  2. Distributed Algorithms for SCC Decomposition

    Microsoft Academic Search

    Jiri Barnat; Jakub Chaloupka; Jaco van de Pol

    2011-01-01

    We study existing parallel algorithms for the decomposition of a partitioned graph into its strongly connected components (SCCs). In particular, we identify several individual procedures that the algorithms are assembled from and show how to assemble a new and more efficient algorithm, called Recursive OBF (OBFR), to solve the decomposition problem. We also report on a thorough experimental study to

  3. Logic-Based Benders Decomposition

    Microsoft Academic Search

    J. n. Hooker

    1995-01-01

    Benders decomposition uses a strategy of "learning from one's mistakes" that has been employed in a more general way by constraint satisfactionmethods. The aim of this paper is to achieve some of the generalityof the latter methods while exploiting problem structure in much the waythat is done by Benders decomposition. This is accomplished by extendingBenders\\

  4. The Study of Dusty Star-Forming Galaxies in the Early Universe Through Far-Infrared Observations

    NASA Astrophysics Data System (ADS)

    Calanog, Jae Alyson

    In this thesis I use far-infrared (far-IR) observations performed by the Herschel Space Observatory to study dusty star-forming galaxies, which are believed to be the likely progenitors of massive elliptical galaxies. More specifically, I investigate the far-IR emission of dust-obscured galaxies (DOGs), analyze the near-IR imaging of Herschel-selected lensed galaxies, and investigate the rest-frame UV emission of HFLS3, a z = 6.34 Herschel-selected starburst.

  5. Early-type stars observed in the ESO UVES Paranal Observatory Project - V. Time-variable interstellar absorption

    E-print Network

    McEvoy, Catherine M; Dufton, Philip L; Smith, Keith T; Kennedy, Michael B; Keenan, Francis P; Lambert, David L; Welty, Daniel E; Lauroesch, James T

    2015-01-01

    The structure and properties of the diffuse interstellar medium (ISM) on small scales, sub-au to 1 pc, are poorly understood. We compare interstellar absorption-lines, observed towards a selection of O- and B-type stars at two or more epochs, to search for variations over time caused by the transverse motion of each star combined with changes in the structure in the foreground ISM. Two sets of data were used: 83 VLT- UVES spectra with approximately 6 yr between epochs and 21 McDonald observatory 2.7m telescope echelle spectra with 6 - 20 yr between epochs, over a range of scales from 0 - 360 au. The interstellar absorption-lines observed at the two epochs were subtracted and searched for any residuals due to changes in the foreground ISM. Of the 104 sightlines investigated with typically five or more components in Na I D, possible temporal variation was identified in five UVES spectra (six components), in Ca II, Ca I and/or Na I absorption-lines. The variations detected range from 7\\% to a factor of 3.6 in co...

  6. Observational evidence against mountain-wave generation of ice nuclei as a prerequisite for the formation of three solid nitric acid polar stratospheric clouds observed in the Arctic in early December 1999

    NASA Astrophysics Data System (ADS)

    Pagan, Kathy L.; Tabazadeh, Azadeh; Drdla, Katja; Hervig, Mark E.; Eckermann, Stephen D.; Browell, Edward V.; Legg, Marion J.; Foschi, Patricia G.

    2004-02-01

    A number of recently published papers suggest that mountain-wave activity in the stratosphere, producing ice particles when temperatures drop below the ice frost point, may be the primary source of large NAT particles. In this paper we use measurements from the Advanced Very High Resolution Radiometer (AVHRR) instruments on board the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites to map out regions of ice clouds produced by stratospheric mountain-wave activity inside the Arctic vortex. Lidar observations from three DC-8 flights in early December 1999 show the presence of solid nitric acid (Type Ia or NAT) polar stratospheric clouds (PSCs). By using back trajectories and superimposing the position maps on the AVHRR cloud imagery products, we show that these observed NAT clouds could not have originated at locations of high-amplitude mountain-wave activity. We also show that mountain-wave PSC climatology data and Mountain Wave Forecast Model 2.0 (MWFM-2) raw hemispheric ray and grid box averaged hemispheric wave temperature amplitude hindcast data from the same time period are in agreement with the AVHRR data. Our results show that ice cloud formation in mountain waves cannot explain how at least three large-scale NAT clouds were formed in the stratosphere in early December 1999.

  7. Evidence of laser induced decomposition of triaminotrinitrobenzene from surface enhanced Raman spectroscopy

    Microsoft Academic Search

    F. J. Owens

    2011-01-01

    It is observed that the focused 632 nm laser of the confocal micro-Raman spectrometer decomposes triaminotrinitrobenzene (TATB). The temperature generated in the laser spot determined by measuring the ratio of the intensities of the anti-Stokes to Stokes spectra is too low to cause thermal decomposition. The observed decomposition is suggested to be a result of laser induced electronic excitation. The

  8. X-Ray, UV, and Optical Observations of Supernova 2006bp with Swift: Detection of Early X-Ray Emission

    E-print Network

    S. Immler; P. J. Brown; P. Milne; L. Dessart; P. A. Mazzali; W. Landsman; N. Gehrels; R. Petre; D. N. Burrows; J. A. Nousek; R. A. Chevalier; C. L. Williams; M. Koss; C. J. Stockdale; M. T. Kelley; K. W. Weiler; S. T. Holland; E. Pian; P. W. A. Roming; D. Pooley; K. Nomoto; J. Greiner; S. Campana; A. M. Soderberg

    2007-03-29

    We present results on the X-ray and optical/UV emission from the type IIP SN 2006bp and the interaction of the SN shock with its environment, obtained with the X-Ray Telescope (XRT) and UV/Optical Telescope (UVOT) on-board the Swift observatory. SN 2006bp is detected in X-rays at a 4.5 sigma level of significance in the merged XRT data from days 1 to 12 after the explosion. If the X-ray luminosity of (1.8+/-0.4)E39 ergs/s is caused by interaction of the SN shock with circumstellar material (CSM), deposited by a stellar wind from the progenitor's companion star, a mass-loss rate of ~E-05 M_sun/yr is inferred. The mass-loss rate is consistent with the non-detection in the radio with the VLA on days 2, 9, and 11 after the explosion and characteristic of a red supergiant progenitor with a mass around 12-15 M_sun prior to the explosion. In combination with a follow-up XMM-Newton observation obtained on day 21 after the explosion, an X-ray rate of decline with index 1.2+/-0.6 is inferred. Since no other SN has been detected in X-rays prior to the optical peak and since type IIP SNe have an extended 'plateau' phase in the optical, we discuss the scenario that the X-rays might be due to inverse Compton scattering of photospheric optical photons off relativistic electrons produced in circumstellar shocks. However, due to the high required value of the Lorentz factor (~10-100) we conclude that Inverse Compton scattering is an unlikely explanation for the observed X-ray emission. The fast evolution of the optical/ultraviolet spectral energy distribution and the spectral changes observed with Swift reveal the onset of metal line-blanketing and cooling of the expanding photosphere during the first few weeks after the outburst.

  9. One Dose versus Three Weekly Doses of Benzathine Penicillin G for Patients Co-Infected with HIV and Early Syphilis: A Multicenter, Prospective Observational Study

    PubMed Central

    Yang, Chia-Jui; Lee, Nan-Yao; Chen, Tun-Chieh; Lin, Yu-Hui; Liang, Shiou-Haur; Lu, Po-Liang; Huang, Wen-Chi; Tang, Hung-Jen; Lee, Chen-Hsiang; Lin, Hsi-Hsun; Chen, Yen-Hsu; Ko, Wen-Chien; Hung, Chien-Ching

    2014-01-01

    Background One dose of benzathine penicillin G (BPG) has been recommended for HIV-infected patients with early syphilis (primary, secondary, and early latent syphilis) in the sexually transmitted diseases treatment guidelines, but clinical data to support such a recommendation are limited. Methods We prospectively observed the serological response to 1 or 3 weekly doses of BPG in HIV-infected adults who sought treatment of early syphilis at 8 hospitals around Taiwan. Rapid plasma reagin (RPR) titers were followed every 3–6 months after treatment. The serological response was defined as a 4-fold or greater decline in RPR titers at 12 months of treatment. The missing values were treated by following the last-observed-carried-forward principle. We hypothesized that 1 dose was non-inferior to 3 weekly doses of BPG with the non-inferiority margin for the difference of serological response set to 10%. Results Between 2007 and 2012, 573 patients completed at least 12 months of follow-up: 295 (51.5%) receiving 1 dose of BPG (1-dose group) and 278 (48.5%) 3 doses (3-dose group). Overall, 198 patients (67.1%; 95% confidence interval [CI], 61.4–72.5%) in the 1-dose group achieved serological response at 12 months, as did 208 patients (74.8%; 95% CI, 69.3–79.8%) in the 3-dose group (one-sided 95% CI of the difference, 15.1%). In the multivariate analysis, secondary syphilis (adjusted odds ratio [AOR], 1.90; 95% CI 1.17–3.09), RPR titer ?32 (AOR, 1.93; 95% CI, 1.38–2.69), and 3 doses of BPG (AOR, 1.68; 95% CI, 1.20–2.36) were independently associated with a serological response. The time to the first episode of treatment failure was 1184 (standard deviation [SD], 70.5) and 1436 (SD, 80.0) days for 1- and 3-dose group, respectively. Conclusions Single-dose BPG resulted in a higher serological failure rate and shorter time to treatment failure than 3 weekly doses of BPG in the treatment of early syphilis in HIV-infected patients. PMID:25286091

  10. Dynamic mode decomposition analysis of detonation waves

    NASA Astrophysics Data System (ADS)

    Massa, L.; Kumar, R.; Ravindran, P.

    2012-06-01

    Dynamic mode decomposition is applied to study the self-excited fluctuations supported by transversely unstable detonations. The focus of this study is on the stability of the limit cycle solutions and their response to forcing. Floquet analysis of the unforced conditions reveals that the least stable perturbations are almost subharmonic with ratio between global mode and fundamental frequency ?i/?f = 0.47. This suggests the emergence of period doubling modes as the route to chaos observed in larger systems. The response to forcing is analyzed in terms of the coherency of the four fundamental energy modes: acoustic, entropic, kinetic, and chemical. Results of the modal decomposition suggest that the self-excited oscillations are quite insensitive to vortical forcing, and maintain their coherency up to a forcing turbulent Mach number of 0.3.

  11. Art of spin decomposition

    E-print Network

    Xiang-Song Chen; Wei-Min Sun; Fan Wang; T. Goldman

    2011-05-31

    We analyze the problem of spin decomposition for an interacting system from a natural perspective of constructing angular momentum eigenstates. We split, from the total angular momentum operator, a proper part which can be separately conserved for a stationary state. This part commutes with the total Hamiltonian and thus specifies the quantum angular momentum. We first show how this can be done in a gauge-dependent way, by seeking a specific gauge in which part of the total angular momentum operator vanishes identically. We then construct a gauge-invariant operator with the desired property. Our analysis clarifies what is the most pertinent choice among the various proposals for decomposing the nucleon spin. A similar analysis is performed for extracting a proper part from the total Hamiltonian to construct energy eigenstates.

  12. Decomposition in northern Minnesota peatlands

    SciTech Connect

    Farrish, K.W.

    1985-01-01

    Decomposition in peatlands was investigated in northern Minnesota. Four sites, an ombrotrophic raised bog, an ombrotrophic perched bog and two groundwater minerotrophic fens, were studied. Decomposition rates of peat and paper were estimated using mass-loss techniques. Environmental and substrate factors that were most likely to be responsible for limiting decomposition were monitored. Laboratory incubation experiments complemented the field work. Mass-loss over one year in one of the bogs, ranged from 11 percent in the upper 10 cm of hummocks to 1 percent at 60 to 100 cm depth in hollows. Regression analysis of the data for that bog predicted no mass-loss below 87 cm. Decomposition estimates on an area basis were 2720 and 6460 km/ha yr for the two bogs; 17,000 and 5900 kg/ha yr for the two fens. Environmental factors found to limit decomposition in these peatlands were reducing/anaerobic conditions below the water table and cool peat temperatures. Substrate factors found to limit decomposition were low pH, high content of resistant organics such as lignin, and shortages of available N and K. Greater groundwater influence was found to favor decomposition through raising the pH and perhaps by introducing limited amounts of dissolved oxygen.

  13. THE RESOLVED STELLAR POPULATION IN 50 REGIONS OF M83 FROM HST/WFC3 EARLY RELEASE SCIENCE OBSERVATIONS

    SciTech Connect

    Kim, Hwihyun; Cohen, Seth H.; Windhorst, Rogier A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Whitmore, Bradley C.; Mutchler, Max; Bond, Howard E. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Chandar, Rupali [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Saha, Abhijit [National Optical Astronomy Observatories, Tucson, AZ 85726-6732 (United States); Kaleida, Catherine C. [Cerro Tololo Inter-American Observatory, La Serena (Chile); Calzetti, Daniela [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); O'Connell, Robert W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Balick, Bruce [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Carollo, Marcella [Department of Physics, ETH-Zurich, Zurich 8093 (Switzerland); Disney, Michael J. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Dopita, Michael A. [Mount Stromlo and Siding Spring Observatories, Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Frogel, Jay A. [Galaxies Unlimited, 1 Tremblant Court, Lutherville, MD 21093 (United States); Hall, Donald N. B. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Holtzman, Jon A. [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Kimble, Randy A. [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); McCarthy, Patrick J., E-mail: hwihyun.kim@asu.edu [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101-1292 (United States); and others

    2012-07-01

    We present a multi-wavelength photometric study of {approx}15,000 resolved stars in the nearby spiral galaxy M83 (NGC 5236, D = 4.61 Mpc) based on Hubble Space Telescope Wide Field Camera 3 observations using four filters: F336W, F438W, F555W, and F814W. We select 50 regions (an average size of 260 pc by 280 pc) in the spiral arm and inter-arm areas of M83 and determine the age distribution of the luminous stellar populations in each region. This is accomplished by correcting for extinction toward each individual star by comparing its colors with predictions from stellar isochrones. We compare the resulting luminosity-weighted mean ages of the luminous stars in the 50 regions with those determined from several independent methods, including the number ratio of red-to-blue supergiants, morphological appearance of the regions, surface brightness fluctuations, and the ages of clusters in the regions. We find reasonably good agreement between these methods. We also find that young stars are much more likely to be found in concentrated aggregates along spiral arms, while older stars are more dispersed. These results are consistent with the scenario that star formation is associated with the spiral arms, and stars form primarily in star clusters and then disperse on short timescales to form the field population. The locations of Wolf-Rayet stars are found to correlate with the positions of many of the youngest regions, providing additional support for our ability to accurately estimate ages. We address the effects of spatial resolution on the measured colors, magnitudes, and age estimates. While individual stars can occasionally show measurable differences in the colors and magnitudes, the age estimates for entire regions are only slightly affected.

  14. COUPLED CANONICAL POLYADIC DECOMPOSITIONS AND (COUPLED) DECOMPOSITIONS IN MULTILINEAR

    E-print Network

    in chemometrics [36]. In recent years coupled canonical polyadic decompositions have had a resurgence in several]. In chemometrics it has been suggested that coupled matrix- tensor factorizations can be used to fuse data obtained

  15. Image decomposition based on modified bidimensional empirical mode decomposition

    NASA Astrophysics Data System (ADS)

    Arfia, Faten Ben; Messaoud, Mohamed Ben; Abid, Mohamed

    2011-06-01

    In this paper we develop an adaptive algorithm for decomposition of greyscales images. This method is highly adaptive decomposition image called Bidimentional Empirical Mode Decomposition (BEMD). It is based on the characterization of the image through its decomposition in Intrinsic Mode Function (IMF) where it can be decomposed into basis functions called IMF and a residue. This method offered a good result in visual quality, unfortunately this method consume an important execution time. To overcome this problem we proposed a new approach using Block based BEMD method where the input image is subdivided into blocks. Then the BEMD is applied on each of the four blocks separately. This method offered a good solution to reduce the execution time.

  16. Decomposition rates and termite assemblage composition in semiarid Africa

    USGS Publications Warehouse

    Schuurman, G.

    2005-01-01

    Outside of the humid tropics, abiotic factors are generally considered the dominant regulators of decomposition, and biotic influences are frequently not considered in predicting decomposition rates. In this study, I examined the effect of termite assemblage composition and abundance on decomposition of wood litter of an indigenous species (Croton megalobotrys) in five terrestrial habitats of the highly seasonal semiarid Okavango Delta region of northern Botswana, to determine whether natural variation in decomposer community composition and abundance influences decomposition rates. 1 conducted the study in two areas, Xudum and Santawani, with the Xudum study preceding the Santawani study. I assessed termite assemblage composition and abundance using a grid of survey baits (rolls of toilet paper) placed on the soil surface and checked 2-4 times/month. I placed a billet (a section of wood litter) next to each survey bait and measured decomposition in a plot by averaging the mass loss of its billets. Decomposition rates varied up to sixfold among plots within the same habitat and locality, despite the fact that these plots experienced the same climate. In addition, billets decomposed significantly faster during the cooler and drier Santawani study, contradicting climate-based predictions. Because termite incidence was generally higher in Santawani plots, termite abundance initially seemed a likely determinant of decomposition in this system. However, no significant effect of termite incidence on billet mass loss rates was observed among the Xudum plots, where decomposition rates remained low even though termite incidence varied considerably. Considering the incidences of fungus-growing termites and non-fungus-growing termites separately resolves this apparent contradiction: in both Santawani and Xudum, only fungus-growing termites play a significant role in decomposition. This result is mirrored in an analysis of the full data set of combined Xudum and Santawani data. The determination that natural variation in the abundance of a single taxonomic group of soil fauna, a termite subfamily, determines almost all observed variation in decomposition rates supports the emerging view that biotic influences may be important in many biomes and that consideration of decomposer community composition and abundance may be critical for accurate prediction of decomposition rates. ?? 2005 by the Ecological Society of America.

  17. Descent theory for semiorthogonal decompositions

    SciTech Connect

    Elagin, Alexei D

    2012-05-31

    We put forward a method for constructing semiorthogonal decompositions of the derived category of G-equivariant sheaves on a variety X under the assumption that the derived category of sheaves on X admits a semiorthogonal decomposition with components preserved by the action of the group G on X. This method is used to obtain semiorthogonal decompositions of equivariant derived categories for projective bundles and blow-ups with a smooth centre as well as for varieties with a full exceptional collection preserved by the group action. Our main technical tool is descent theory for derived categories. Bibliography: 12 titles.

  18. Discovery and preliminary confirmation of novel early detection biomarkers for triple-negative breast cancer using preclinical plasma samples from the Women’s Health Initiative observational study

    PubMed Central

    Li, Christopher I.; Mirus, Justin E.; Zhang, Yuzheng; Ramirez, Arturo B.; Ladd, Jon J.; Prentice, Ross L.; McIntosh, Martin; Hanash, Samir M.; Lampe, Paul D.

    2012-01-01

    Triple-negative breast cancer is a particularly aggressive and lethal breast cancer subtype that is more likely to be interval-detected rather than screen-detected. The purpose of this study is to discover and initially validate novel early detection biomarkers for triple-negative breast cancer using preclinical samples. Plasma samples collected up to 17 months prior to diagnosis from 28 triple-negative cases and 28 matched controls from the Women’s Health Initiative Observational Study were equally divided into a training set and a test set and interrogated using a customized antibody array. Data were available on 889 antibodies, and in the training set statistically significant differences in case vs. control signals were observed for 93 (10.5%) antibodies at p<0.05. Of these 93 candidates, 29 were confirmed in the test set at p<0.05. Areas under the curve for these candidates ranged from 0.58 to 0.79. With specificity set at 98%, sensitivity ranged from 4% to 68% with ?20 candidates having a sensitivity 20% and 6 having a sensitivity ?40%. In an analysis of KEGG gene sets, the pyrimidine metabolism gene set was upregulated in cases compared to controls (p=0.004 in the testing set) and the JAK/Stat signaling pathway gene set was downregulated (p=0.003 in the testing set). Numerous potential early detection biomarkers specific to triple-negative breast cancer in multiple pathways were identified. Further research is required to follow-up on promising candidates in larger sample sizes and to better understand their potential biological importance as our understanding of the etiology of triple-negative breast cancer continues to grow. PMID:22903690

  19. Photoinitiated decomposition of HNCO

    NASA Astrophysics Data System (ADS)

    Zyrianov, Mikhail

    1998-09-01

    The photoinitiated decomposition of expansion-cooled isocyanic acid (HNCO) following S1(A'' 1)<--S0( A'1) excitation via channels (1)3NH + CO, (2)H + NCO, and (3)1NH + CO [where 3NH and 1NH denote NH(X3?- ) and NH(a1?), respectively] has been investigated in the 260-220 nm photolysis range by means of laser induced fluorescence and photofragment ion imaging. Three aspects were emphasized: (i)thermochemistry; (ii)product state distributions and branching ratios; and (iii)time scales for product appearance. The thermochemical studies included determinations of appearance threshold energies and barrier heights. The thresholds for channel (2) and (3) were determined from photofragment yield spectra and product state distributions. The barrier height to channel (3) dissociation on S1 was determined using the imaging technique. Studies of product state distributions establish the mechanisms of dissociation to the different channels. Images of CO products from channels (1) and (3) were obtained in ~230 nm photolysis. The resolution in the velocity domain allowed separate measurements of the spectra of CO correlated with 3NH and 1NH. Global and correlated distributions of 1NH and CO demonstrated that S, decomposition to channel (3) predominates, and is controlled by exit channel dynamics. Analysis of the NCO rotational distributions shows good agreement with phase space theory and indicates dissociation on S0 proceeding without a barrier, but with angular momentum constraints. The 1NH/3NH branching ratio increases rapidly above the channel (3) threshold. Dissociation time scales were obtained by examining the anisotropy of the images. At 230 nm, the image of CO from channel (3) yields ? = -0.80 corresponding to <1 ps appearance time. In contrast, hydrogen and channel (1) CO images are isotropic, indicating appearance times >5 ps. It is concluded that up to and around the channel (3) threshold the main dissociation mechanisms are: S1-->S0-->T1--> N3H+CO for channel (1); S1-->S0-->H+NCO for channel (2); and S1-->N1H+CO for channel (3). At higher excitation energies, all three pathways remain active, but additional surfaces may participate.

  20. Thermal decomposition of ethylpentaborane in gas phase

    NASA Technical Reports Server (NTRS)

    Mcdonald, Glen E

    1956-01-01

    The thermal decomposition of ethylpentaborane at temperatures of 185 degrees to 244 degrees C is approximately a 1.5-order reaction. The products of the decomposition were hydrogen, methane, a nonvolatile boron hydride, and traces of decaborane. Measurements of the rate of decomposition of pentaborane showed that ethylpentaborane has a greater rate of decomposition than pentaborane.

  1. The discrepancy between OH production rates deduced from radio and ultraviolet observations of comets. I - A comparative study of OH radio and UV observations of P/Halley 1986 III in late November and early December 1985

    NASA Astrophysics Data System (ADS)

    Gerard, E.

    1990-04-01

    OH UV and radio observations of P/Halley in late November and early December have been combined to determine the quenching radius, the total number of radicals in the coma, the OH lifetime, and the OH production rate. The convolution of the UV brightness profile by the radio antenna beams leads to a quenching radius of 65,000 + or - 15,000 km or 70,000 + or - 20,000 km, depending on the quenching model. A new method is proposed for determining the OH lifetime using the moments of the UV strip brightness distribution and of the radio line profile: the OH lifetime, reduced to 1 AU, is 110,000 + or - 30,000 s. and only weakly model-dependent. With these parameters, the UV and radio OH production rates in December 1985 are in reasonable agreement.

  2. The combinatorics of reduced decompositions

    E-print Network

    Tenner, Bridget Eileen

    2006-01-01

    This thesis examines several aspects of reduced decompositions in finite Coxeter groups. Effort is primarily concentrated on the symmetric group, although some discussions are subsequently expanded to finite Coxeter groups ...

  3. Algorithm for singular value decomposition

    SciTech Connect

    Ross, D.C.

    1984-01-01

    An iterative algorithm for the singular value decomposition (SVD) of a non-zero m x n matrix M is described and illustrated numerically. Derivations of the algorithm and sufficient conditions for convergence are outlined.

  4. Lignocellulose decomposition by microbial secretions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbon storage in terrestrial ecosystems is contingent upon the natural resistance of plant cell wall polymers to rapid biological degradation. Nevertheless, certain microorganisms have evolved remarkable means to overcome this natural resistance. Lignocellulose decomposition by microorganisms com...

  5. Coxeter Decompositions of Hyperbolic Tetrahedra

    Microsoft Academic Search

    A. Felikson

    2002-01-01

    We classify Coxeter decompositions of hyperbolic tetrahedra, i.e. simplices\\u000ain the hyperbolic space H^3. The paper completes the classification of Coxeter\\u000adecompositions of hyperbolic simplices.

  6. Nontraditional tensor decompositions and applications.

    SciTech Connect

    Bader, Brett William

    2010-07-01

    This presentation will discuss two tensor decompositions that are not as well known as PARAFAC (parallel factors) and Tucker, but have proven useful in informatics applications. Three-way DEDICOM (decomposition into directional components) is an algebraic model for the analysis of 3-way arrays with nonsymmetric slices. PARAFAC2 is a related model that is less constrained than PARAFAC and allows for different objects in one mode. Applications of both models to informatics problems will be shown.

  7. Optimization by nonhierarchical asynchronous decomposition

    NASA Technical Reports Server (NTRS)

    Shankar, Jayashree; Ribbens, Calvin J.; Haftka, Raphael T.; Watson, Layne T.

    1992-01-01

    Large scale optimization problems are tractable only if they are somehow decomposed. Hierarchical decompositions are inappropriate for some types of problems and do not parallelize well. Sobieszczanski-Sobieski has proposed a nonhierarchical decomposition strategy for nonlinear constrained optimization that is naturally parallel. Despite some successes on engineering problems, the algorithm as originally proposed fails on simple two dimensional quadratic programs. The algorithm is carefully analyzed for quadratic programs, and a number of modifications are suggested to improve its robustness.

  8. Instability and decomposition on the surface of strained alloy films

    NASA Astrophysics Data System (ADS)

    Huang, Zhi-Feng; Desai, Rashmi C.

    2002-05-01

    A continuum dynamical model is developed to determine the morphological and compositional instabilities on the free surface of heteroepitaxial alloy films in the absence of growth. We use a linear stability analysis to study the early nonequilibrium processes of surface evolution, and calculate the stability conditions and diagrams for different cases of material parameters. There are two key considerations in our treatment: the coupling between top free surface of the film and the bulk phase underneath, and the dependence of both Young's and shear elastic moduli on local composition. The combination and interplay of different elastic effects caused by lattice misfit between film and substrate (misfit strain), composition dependence of film lattice parameter (compositional strain), and of film elastic constants lead to complicated and rich stability results, in particular the joint stability or instability for morphological and compositional profiles, the asymmetry between tensile and compressive layers, as well as the possible stabilization and suppression of surface decomposition even below the effective critical temperature. We also compare our results with the observations of some postdeposition annealing experiments.

  9. Constraining Galaxy Evolution With Bulge-Disk-Bar Decomposition

    E-print Network

    Tim Weinzirl; Shardha Jogee; Fabio D. Barazza

    2008-02-26

    Structural decomposition of galaxies into bulge, disk, and bar components is important to address a number of scientific problems. Measuring bulge, disk, and bar structural parameters will set constraints on the violent and secular processes of galaxy assembly and recurrent bar formation and dissolution models. It can also help to quantify the fraction and properties of bulgeless galaxies (those systems having no bulge or only a relatively insignificant disky-pseudobulges), which defy galaxy formation paradigms requiring almost every disk galaxy to have a classical bulge at its core. We demonstrate a proof of concept and show early results of our ongoing three-component bulge-disk-bar decomposition of NIR images for a sample of three complementary samples spanning different epochs and different environments (field and cluster). In contrast to most early studies, which only attempt two-component bulge-disk decomposition, we fit three components using GALFIT: a bulge, a disk, and a bar. We show that it is important to include the bar component, as this can significantly lower the bulge-to-total luminosity ratio (B/T), in many cases by a factor of two or more, thus effectively changing the Hubble type of a galaxy from early to late.

  10. Kinetics of the pyrolytic and hydrothermal decomposition of water hyacinth.

    PubMed

    Luo, Guang'en; Strong, P James; Wang, Hailong; Ni, Wuzhong; Shi, Weiyong

    2011-07-01

    The kinetics of water hyacinth decomposition using pyrolysis and hydrothermal treatment was compared. With pyrolysis, initial vaporization occurred at 453 K as determined by thermogravimetric analysis, while initial solubilisation occurred at 433 K with subcritical hydrothermal treatment. The "kinetic triplet" was determined for the ranges of 423-483 K (range I) and 473-553 K (range II) using the Coats-Redfern method for both treatments. The calculated activation energies for ranges I and II were 110 and 116 kJ/mol for conventional pyrolysis and 145 and 90 kJ/mol for hydrothermal treatment. The similar activation energies for the two temperature ranges observed for pyrolysis implied that only hemicellulose decomposition occurred. For hydrothermal treatment, both hemicellulose and cellulose decomposition occurred in temperature range II, in which a notable lower activation energy was observed. This implied hydrothermal treatment was more suitable for conversion lignocellulosic biomass under these conditions. PMID:21558054

  11. Decomposition of peat from upland boreal forest: Temperature dependence and sources of respired carbon

    E-print Network

    Litvak, Marcy

    Decomposition of peat from upland boreal forest: Temperature dependence and sources of respired boreal peat under black spruce forest with sphagnum and feather moss understory using incubation increments. At temperatures below 0°C, significant decomposition was observed in feather moss peat

  12. Naphthalene and acenaphthene decomposition by electron beam generated plasma application

    SciTech Connect

    Ostapczuk, A.; Hakoda, T.; Shimada, A.; Kojima, T. [Institute for Nuclear Chemistry and Technology, Warsaw (Poland)

    2008-08-15

    The application of non-thermal plasma generated by electron beam (EB) was investigated in laboratory scale to study decomposition of polycyclic aromatic hydrocarbons like naphthalene and acenaphthene in flue gas. PAH compounds were treated by EB with the dose up to 8 kGy in dry and humid base gas mixtures. Experimentally established G-values gained 1.66 and 3.72 mol/100 eV for NL and AC at the dose of 1 kGy. NL and AC removal was observed in dry base gas mixtures showing that the reaction with OH radical is not exclusive pathway to initialize PAH decomposition; however in the presence of water remarkably higher decomposition efficiency was observed. As by-products of NL decomposition were identified compounds containing one aromatic ring and oxygen atoms besides CO and CO{sub 2}. It led to the conclusion that PAH decomposition process in humid flue gas can be regarded as multi-step oxidative de-aromatization analogical to its atmospheric chemistry.

  13. Surgical Data and Early Postoperative Outcomes after Minimally Invasive Lumbar Interbody Fusion: Results of a Prospective, Multicenter, Observational Data-Monitored Study

    PubMed Central

    Pereira, Paulo; Buzek, David; Franke, Jörg; Senker, Wolfgang; Kosmala, Arkadiusz; Hubbe, Ulrich; Manson, Neil; Rosenberg, Wout; Assietti, Roberto; Martens, Frederic; Barbanti Brodano, Giovanni; Scheufler, Kai-Michael

    2015-01-01

    Minimally invasive lumbar interbody fusion (MILIF) offers potential for reduced operative morbidity and earlier recovery compared with open procedures for patients with degenerative lumbar disorders (DLD). Firm conclusions about advantages of MILIF over open procedures cannot be made because of limited number of large studies of MILIF in a real-world setting. Clinical effectiveness of MILIF in a large, unselected real-world patient population was assessed in this Prospective, monitored, international, multicenter, observational study. Objective: To observe and document short-term recovery after minimally invasive interbody fusion for DLD. Materials and Methods: In a predefined 4-week analysis from this study, experienced surgeons (?30 MILIF surgeries pre-study) treated patients with DLD by one- or two-level MILIF. The primary study objective was to document patients’ short-term post-interventional recovery (primary objective) including back/leg pain (visual analog scale [VAS]), disability (Oswestry Disability Index [ODI]), health status (EQ-5D) and Patient satisfaction. Results: At 4 weeks, 249 of 252 patients were remaining in the study; the majority received one-level MILIF (83%) and TLIF was the preferred approach (94.8%). For one-level (and two-level) procedures, surgery duration was 128 (182) min, fluoroscopy time 115 (154) sec, and blood-loss 164 (233) mL. Time to first ambulation was 1.3 days and time to study-defined surgery recovery was 3.2 days. Patients reported significantly (P < 0.0001) reduced back pain (VAS: 2.9 vs 6.2), leg pain (VAS: 2.5 vs 5.9), and disability (ODI: 34.5% vs 45.5%), and a significantly (P < 0.0001) improved health status (EQ-5D index: 0.61 vs 0.34; EQ VAS: 65.4 vs 52.9) 4 weeks postoperatively. One adverse event was classified as related to the minimally invasive surgical approach. No deep site infections or deaths were reported. Conclusions: For experienced surgeons, MILIF for DLD demonstrated early benefits (short time to first ambulation, early recovery, high patient satisfaction and improved patient-reported outcomes) and low major perioperative morbidity at 4 weeks postoperatively. PMID:25811615

  14. An observational cohort study to determine efficacy, adherence and outcome of the early initiation of pressure support ventilation during mechanical ventilation

    PubMed Central

    Glover, Guy; Connolly, Bronwen; Di Gangi, Stefania; Ayers, Lisa; Terblanche, Marius; Beale, Richard; Hart, Nicholas

    2014-01-01

    Background Timely initiation of weaning from mechanical ventilation (MV) is important. Non-validated screening criteria may delay weaning if too prescriptive. This study observed physician-led utilisation of pressure support ventilation (PSV), referenced to four reported conventional screening criteria hypothesising that these criteria would have delayed the weaning progress. Methods A prospective observational cohort study of adult patients receiving MV in a 30-bed university hospital intensive care unit (ICU). Logistic regression analysis identified factors associated with PSV failure. Outcome is reported according to adherence to the screening criteria. Results 209 patients were included (age 62.6±15.9?years, male:female 115:94, Acute Physiology and Chronic Health Evaluation (APACHE) II 16.7±6.1). Median (IQR) time to initiate PSV was 11.0 (5.0–22.0) h, and duration of weaning to extubation was 43.0 (13.0–121.5) h. PSV weaning was initiated despite significant hypoxia (partial pressure of arterial oxygen to fraction of inspired oxygen ratio (PaO2:FiO2) 35.8±15.9?kPa), moderate positive end-expiratory pressure levels (7.5±2.5?cm?H2O), deep sedation (44% Richmond Agitation and Sedation Scale (RASS) ??3) and cardiovascular instability (48.8%). At PSV initiation, 85% of patients violated at least one screening criterion, yet 74.6% of patients remained stable for 24?h and 25.4% of patients were successfully extubated within 12?h. There was no association between individual screening criteria and PSV failure. Failure to sustain a PSV trial was associated with ventilation >7?days (RR=2.12 (1.33 to 3.38), p=0.002) and ICU mortality (RR=2.94 (1.46 to 5.94), p=0.002). Conclusions Physician-led transition to PSV and weaning was often initiated early and successfully before patients fulfilled conventional screening criteria. Failure to sustain a PSV trial could be an early indicator of prolonged MV and ICU mortality and warrants further investigation. These data support the view that current screening criteria may delay initiation of weaning. PMID:25478179

  15. Rank-based decompositions of morphological templates.

    PubMed

    Sussner, P; Ritter, G X

    2000-01-01

    Methods for matrix decomposition have found numerous applications in image processing, in particular for the problem of template decomposition. Since existing matrix decomposition techniques are mainly concerned with the linear domain, we consider it timely to investigate matrix decomposition techniques in the nonlinear domain with applications in image processing. The mathematical basis for these investigations is the new theory of rank within minimax algebra. Thus far, only minimax decompositions of rank 1 and rank 2 matrices into outer product expansions are known to the image processing community. We derive a heuristic algorithm for the decomposition of matrices having arbitrary rank. PMID:18262978

  16. Stellar Populations of Lyman Break Galaxies at z=1-3 in the HST/WFC3 Early Release Science Observations

    E-print Network

    Hathi, N P; Ryan, R E; Finkelstein, S L; McCarthy, P J; Windhorst, R A; Yan, H; Koekemoer, A M; Rutkowski, M J; O'Connell, R W; Straughn, A N; Balick, B; Bond, H E; Calzetti, D; Disney, M J; Dopita, M A; Frogel, J A; Hall, D N B; Holtzman, J A; Kimble, R A; Paresce, F; Saha, A; Silk, J I; Trauger, J T; Walker, A R; Whitmore, B C; Young, E T

    2012-01-01

    We analyze the spectral energy distributions (SEDs) of Lyman break galaxies (LBGs) at z=1-3 selected using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) UVIS channel filters. These HST/WFC3 observations cover about 50 sq. arcmin in the GOODS-South field as a part of the WFC3 Early Release Science program. These LBGs at z=1-3 are selected using dropout selection criteria similar to high redshift LBGs. The deep multi-band photometry in this field is used to identify best-fit SED models, from which we infer the following results: (1) the photometric redshift estimate of these dropout selected LBGs is accurate to within few percent; (2) the UV spectral slope {\\beta} is redder than at high redshift (z>3), where LBGs are less dusty; (3) on average, LBGs at z=1-3 are massive, dustier and more highly star-forming, compared to LBGs at higher redshifts with similar luminosities, though their median values are similar within 1{\\sigma} uncertainties. This could imply that identical dropout selection techniq...

  17. Early Science with the Large Millimeter Telescope: Observations of dust continuum and CO emission lines of cluster-lensed submillimetre galaxies at z=2.0-4.7

    E-print Network

    Zavala, J A; Aretxaga, I; Hughes, D H; Wilson, G W; Geach, J E; Egami, E; Gurwell, M A; Wilner, D J; Smail, Ian; Blain, A W; Chapman, S C; Coppin, K E K; Dessauges-Zavadsky, M; Edge, A C; Montana, A; Nakajima, K; Rawle, T D; Sanchez-Arguelles, D; Swinbank, A M; Webb, T M A; Zeballos, M

    2015-01-01

    We present Early Science observations with the Large Millimeter Telescope, AzTEC 1.1 mm continuum images and wide bandwidth spectra (73-111 GHz) acquired with the Redshift Search Receiver (RSR), towards four bright lensed submillimetre galaxies identified through the Herschel Lensing Survey-snapshot and the SCUBA-2 Cluster Snapshot Survey. This pilot project studies the star formation history and the physical properties of the molecular gas and dust content of the highest redshift galaxies identified through the benefits of gravitational magnification. We robustly detect dust continuum emission for the full sample and CO emission lines for three of the targets. We find that one source shows spectroscopic multiplicity and is a blend of three galaxies at different redshifts (z=2.040, 3.252 and 4.680), reminiscent of previous high-resolution imaging follow-up of unlensed submillimetre galaxies, but with a completely different search method, that confirm recent theoretical predictions of physically unassociated b...

  18. Early irradiation effects observed on magnetic resonance imaging and angiography, and positron emission tomography for arteriovenous malformations treated by Gamma Knife radiosurgery.

    PubMed

    Guo, W Y; Pan, D H; Liu, R S; Chung, W Y; Shiau, C Y; Cheng, S S; Chang, C Y; Chen, K Y; Yeh, S H; Lee, L S

    1995-01-01

    In 14 patients (7 males and 7 females, age 16-49, mean 29 years), medium-to-large arteriovenous malformations (AVMs; nidus volume 3.5-17.5 cm3, mean 9.4 cm3) were treated by Gamma Knife radiosurgery. Stereotactic MR and conventional angiography were included for targeting to improve targeting accuracy and tissue content in the irradiation volume. Maximum irradiation doses to the nidi were 36-40 Gy (mean 38.9 Gy) and minimum target doses were 18-24 Gy (mean 20 Gy). MR images and MR angiography demonstrated decreasing caliber of feeding vessels and AVM nidus volumes from an early stage, 3 months after radiosurgery, which indicated improvement in cerebral hemodynamics. The improvement correlated well with that observed on PET using [18F]fluorodeoxyglucose (FDG) and with the patients' clinical condition. MR creates an opportunity to monitor treatment effects in a completely noninvasive manner, while conventional angiography remains necessary for verifying complete obliteration of AVMs. More patients and longer follow-ups are needed for clarifying the role of MR techniques in radiosurgery for AVMs. PMID:8584836

  19. Researches on the Nankai trough mega thrust earthquake seismogenic zones using real time observing systems for advanced early warning systems and predictions

    NASA Astrophysics Data System (ADS)

    Kaneda, Yoshiyuki

    2015-04-01

    We recognized the importance of real time monitoring on Earthquakes and Tsunamis Based on lessons learned from 2004 Sumatra Earthquake/Tsunamis and 2011 East Japan Earthquake. We deployed DONET1 and are developing DONET2 as real time monitoring systems which are dense ocean floor networks around the Nankai trough seismogenic zone Southwestern Japan. Total observatories of DONE1 and DONET2 are 51 observatories equipped with multi kinds of sensors such as the accelerometer, broadband seismometer, pressure gauge, difference pressure gauge, hydrophone and thermometer in each observatory. These systems are indispensable for not only early warning of Earthquakes/ Tsunamis, but also researches on broadband crustal activities around the Nankai trough seismogenic zone for predictions. DONET1 detected offshore tsunamis 15 minutes earlier than onshore stations at the 2011 East Japan earthquake/tsunami. Furthermore, DONET1/DONET2 will be expected to monitor slow events such as low frequency tremors and slow earthquakes for the prediction researches. Finally, the integration of observations and simulation researches will contribute to estimate of seismic stage changes from the inter-seismic to pre seismic stage. I will introduce applications of DONET1/DONET2 data and advanced simulation researches.

  20. SeismoGeodesy: Combination of High Rate, Real-time GNSS and Accelerometer Observations and Rapid Seismic Event Notification for Earth Quake Early Warning and Volcano Monitoring

    NASA Astrophysics Data System (ADS)

    Jackson, Michael; Zimakov, Leonid; Moessmer, Matthias

    2015-04-01

    Scientific GNSS networks are moving towards a model of real-time data acquisition, epoch-by-epoch storage integrity, and on-board real-time position and displacement calculations. This new paradigm allows the integration of real-time, high-rate GNSS displacement information with acceleration and velocity data to create very high-rate displacement records. The mating of these two instruments allows the creation of a new, very high-rate (200 Hz) displacement observable that has the full-scale displacement characteristics of GNSS and high-precision dynamic motions of seismic technologies. It is envisioned that these new observables can be used for earthquake early warning studies, volcano monitoring, and critical infrastructure monitoring applications. Our presentation will focus on the characteristics of GNSS, seismic, and strong motion sensors in high dynamic environments, including historic earthquakes replicated on a shake table over a range of displacements and frequencies. We will explore the optimum integration of these sensors from a filtering perspective including simple harmonic impulses over varying frequencies and amplitudes and under the dynamic conditions of various earthquake scenarios. We will also explore the tradeoffs between various GNSS processing schemes including real-time precise point positioning (PPP) and real-time kinematic (RTK) as applied to seismogeodesy. In addition we will discuss implementation of a Rapid Seismic Event Notification System that provides quick delivery of digital data from seismic stations to the acquisition and processing center and a full data integrity model for real-time earthquake notification that provides warning prior to significant ground shaking.

  1. Metric Learning Using Iwasawa Decomposition.

    PubMed

    Jian, Bing; Vemuri, Baba C

    2007-10-01

    Finding a good metric over the input space plays a fundamental role in machine learning. Most existing techniques use the Mahalanobis metric without incorporating the geometry of positive matrices and experience difficulties in the optimization procedure. In this paper we introduce the use of Iwasawa decomposition, a unique and effective parametrization of symmetric positive definite (SPD) matrices, for performing metric learning tasks. Unlike other previously employed factorizations, the use of the Iwasawa decomposition is able to reformulate the semidefinite programming (SDP) problems as smooth convex nonlinear programming (NLP) problems with much simpler constraints. We also introduce a modified Iwasawa coordinates for rank-deficient positive semidefinite (PSD) matrices which enables the unifying of the metric learning and linear dimensionality reduction. We show that the Iwasawa decomposition can be easily used in most recent proposed metric learning algorithms and have applied it to the Neighbourhood Components Analysis (NCA). The experimental results on several public domain datasets are also presented. PMID:19172169

  2. Missing point estimation in models described by proper orthogonal decomposition

    E-print Network

    Peraire, Jaime

    Missing point estimation in models described by proper orthogonal decomposition Patricia Astrid is determined from observed or P. Astrid, S. Weiland and A.C.P.M. Backx are with the De- partment of Electrical, The Netherlands p.astrid@tue.nl, s.weiland@tue.nl, a.c.p.m.backx@tue.nl K. Willcox is with the Department

  3. Target coherence analysis using canonical correlation decomposition for SAS data

    Microsoft Academic Search

    Yinghui Zhao; Neil Wachowski; Mahmood R. Azimi-Sadjadi

    2009-01-01

    This paper analyzes the connection between the canonical correlations of sonar signals captured using two linear hydrophone arrays and the spatial coherence of the sources that are observed. Analysis of this connection allows for the use of a canonical correlation decomposition (CCD) framework for performing synthetic aperture sonar (SAS)-like processing. In particular, it can be used to extract correlation features

  4. Shape Analysis by Graph Decomposition R. Manevich1,

    E-print Network

    Sagiv, Shmuel "Mooly"

    Shape Analysis by Graph Decomposition R. Manevich1, , J. Berdine3 , B. Cook3 , G. Ramalingam2-Verlag Berlin Heidelberg 2007 #12;4 R. Manevich et al. In this paper, we focus on (possibly cyclic) singly an observation by Distefano e

  5. OPTIMAL SPECTRAL DECOMPOSITION (OSD) FOR REMOTELY SENSED OCEAN DATA ASSIMILATION

    E-print Network

    Chu, Peter C.

    with examples of reconstructing the data from the Argo profiling and trajectories, Ocean Surface Current-Salinity Profile Program (GTSPP). Index Terms--Optimal spectral decomposition (OSD), Argo profiling and trajectory data, OSCAR, CODAR, GTSPP 1. INTRODUCTION Remotely observed ocean data from Argo profiling (T, S

  6. Low-Power and Testable Circuit Synthesis Using Shannon Decomposition

    E-print Network

    Bhunia, Swarup

    on Shannon's decomposition and supply gating. We observe that the tree structure of a logic circuit due Terms: Design Additional Key Words and Phrases: Design-for-test, dynamic supply gating, Shannon faults in a circuit. However, relentless device scaling has largely de- teriorated the subthreshold

  7. Convexity Rule for Shape Decomposition Based on Discrete Contour Evolution

    Microsoft Academic Search

    Longin Jan Latecki; Rolf Lakämper

    1999-01-01

    We concentrate here on decomposition of 2D objects into mean- ingful parts of visual form ,o rvisual parts. It is a simple observation that convex parts of objects determine visual parts. However, the problem is that many significant visual parts are not convex, since a visual part may have concavities. We solve this problem by identify- ing convex parts at

  8. Kinematic model of oscillating thermal decomposition reactions of solids

    NASA Astrophysics Data System (ADS)

    Strobel, Hans

    1986-02-01

    A simultaneous system of first-order partial differential equations is proposed for a quasi-isothermal description of experimental results on the decomposition of gypsum obtained by Heide et al. (1980). The equations resemble Volterra-Lotka-type models of population dynamics. They are shown to contain parameter regions leading to self-oscillations and oscillating spatial structures which may explain the observed oscillations of overall decomposition rate. The properties of slightly modified equations with respect to front propagation and creation are inspected for the possibility of providing a second, alternative explanation of experimental facts, basically taking into account the external heating of the sample.

  9. Kinetic modeling of Pt-catalyzed glycolaldehyde decomposition to syngas.

    PubMed

    Salciccioli, Michael; Vlachos, Dionisios G

    2012-05-10

    Fundamental knowledge of the elementary reaction mechanisms involved in oxygenate decomposition on transition metal catalysts can facilitate the optimization of future catalyst and reactor systems for biomass upgrade to fuels and chemicals. Pt-catalyzed decomposition of glycolaldehyde, as the smallest oxygenate with alcohol and aldehyde functionality, was studied via a DFT-based microkinetic model. It was found that two decomposition pathways exist. Under conditions of low hydrogen surface coverage, the initial C-H bond breaking reaction to HOCH(2)CO* is prevalent, while under conditions of high hydrogen coverage, the rather unexpected O-H bond forming reaction to HOCH(2)CHOH* is more active (subsequent decomposition is energetically favorable from HOCH(2)CHOH*). Our results indicate the possibility that (de)hydrogenation chemistry is rate-controlling in many small polyoxygenate biomass derivatives, and suitable catalysts are needed. Finally, DFT was used to understand the increased decomposition activity observed on the surface segregated Ni-Pt-Pt bimetallic catalyst. It was found that the initial O-H bond breaking of glycolaldehyde to OCH(2)CHO* has an activation barrier of just 0.21 eV. This barrier is lower than that of any glycolaldehyde consuming reaction on Pt. These computational predictions are in qualitative agreement with experimental results. PMID:22483365

  10. Photocatalytic decomposition of cortisone acetate in aqueous solution.

    PubMed

    Romão, Joana Sobral; Hamdy, Mohamed S; Mul, Guido; Baltrusaitis, Jonas

    2015-01-23

    The photocatalytic decomposition of cortisone 21-acetate (CA), a model compound for the commonly used steroid, cortisone, was studied. CA was photocatalytically decomposed in a slurry reactor with the initial rates between 0.11 and 0.46 mg L(-1)min(-1) at 10 mg L(-1) concentration, using the following heterogeneous photocatalysts in decreasing order of their catalytic activity: ZnO>Evonik TiO2 P25>Hombikat TiO2>WO3. Due to the lack of ZnO stability in aqueous solutions, TiO2 P25 was chosen for further experiments. The decomposition reaction was found to be pseudo-first order and the rate constant decreased as a function of increasing initial CA concentration. Changing the initial pH of the CA solution did not affect the reaction rate significantly. The decomposition reaction in the presence of the oxidizing sacrificial agent sodium persulfate showed an observed decomposition rate constant of 0.004 min(-1), lower than that obtained for TiO2 P25 (0.040 min(-1)). The highest photocatalytic degradation rate constant was obtained combining both TiO2 P25 and S2O8(2-) (0.071 min(-1)) showing a synergistic effect. No reactive intermediates were detected using LC-MS showing fast photocatalytic decomposition kinetics of CA. PMID:24953705

  11. Exsolution by spinodal decomposition in multicomponent mineral solutions

    PubMed Central

    Petrishcheva, E.; Abart, R.

    2012-01-01

    Phase separation in a three-component system that results from the uphill diffusion of chemical components is considered. The binary decomposition model of Cahn and Hilliard is generalized to account for the interdiffusion of several chemical components with considerably different diffusion constants. Thereafter the decomposition dynamics and the phase relations of the final system state are investigated by means of finite-element modeling. Examples from a hypothetical regular solution and from ternary feldspar are addressed. Special attention is given to situations in which different diffusivities affect decomposition dynamics and the final system states. Good qualitative agreement between our modeling and petrographic observations on exsolved feldspar is achieved. Our model explains systematic deviations from equilibrium element partitioning between the two phases exsolving from an initially homogeneous ternary feldspar during slow cooling. PMID:23888123

  12. Exsolution by spinodal decomposition in multicomponent mineral solutions.

    PubMed

    Petrishcheva, E; Abart, R

    2012-09-01

    Phase separation in a three-component system that results from the uphill diffusion of chemical components is considered. The binary decomposition model of Cahn and Hilliard is generalized to account for the interdiffusion of several chemical components with considerably different diffusion constants. Thereafter the decomposition dynamics and the phase relations of the final system state are investigated by means of finite-element modeling. Examples from a hypothetical regular solution and from ternary feldspar are addressed. Special attention is given to situations in which different diffusivities affect decomposition dynamics and the final system states. Good qualitative agreement between our modeling and petrographic observations on exsolved feldspar is achieved. Our model explains systematic deviations from equilibrium element partitioning between the two phases exsolving from an initially homogeneous ternary feldspar during slow cooling. PMID:23888123

  13. 9 CFR 381.93 - Decomposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Products 2 2010-01-01 2010-01-01 false Decomposition. 381.93 Section 381.93 Animals and Animal Products...Inspection; Disposition of Carcasses and Parts § 381.93 Decomposition. Carcasses of poultry deleteriously affected by...

  14. Tremolite Decomposition and Water on Venus

    NASA Technical Reports Server (NTRS)

    Johnson, N. M.; Fegley, B., Jr.

    2000-01-01

    We present experimental data showing that the decomposition rate of tremolite, a hydrous mineral, is sufficiently slow that it can survive thermal decomposition on Venus over geologic timescales at current and higher surface temperatures.

  15. Finding Unusual Correlation Using Matrix Decompositions

    Microsoft Academic Search

    David B. Skillicorn

    2004-01-01

    \\u000a One important aspect of terrorism detection is the ability to detect small-scale, local correlations against a background\\u000a of large-scale, diffuse correlations. Several matrix decompositions transform correlation into other properties: for example,\\u000a Singular Value Decomposition (SVD) transforms correlation into proximity, and SemiDiscrete Decomposition (SDD) transforms\\u000a correlation into regions of increased density. Both matrix decompositions are effective at detecting local correlation in

  16. Spectral decomposition of broad-line agns and host galaxies

    SciTech Connect

    Vanden Berk, Daniel E.; Shen, Jiajian; /Penn State U., Astron. Astrophys.; Yip, Ching-Wa; /Pittsburgh U.; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Connolly,; /Pittsburgh U.; Burton, Ross E.; /Pittsburgh U. /Case Western Reserve U.; Jester, Sebastian; /Fermilab; Hall, Patrick B.; /York U., Canada; Szalay, Alex S.; /Johns Hopkins; Brinkmann, John; /Apache Point Observ.

    2005-09-01

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line AGN host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among AGN host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasingly bluer than early-type galaxies with increasing host luminosity. Most of the AGNs with detected hosts are emitting at between 1% and 10% of their estimated Eddington luminosities, but the sensitivity of the technique usually does not extend to the Eddington limit. There are mild correlations among the AGN and host galaxy eigencoefficients, possibly indicating a link between recent star formation and the onset of AGN activity. The catalog of spectral reconstruction parameters is available as an electronic table.

  17. Spectral Decomposition of Broad-Line AGNs and Host Galaxies

    E-print Network

    Daniel E. Vanden Berk; Jiajian Shen; Ching-Wa Yip; Donald P. Schneider; Andrew J. Connolly; Ross E. Burton; Sebastian Jester; Patrick B. Hall; Alex S. Szalay; John Brinkmann

    2005-09-13

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line AGN host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among AGN host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasingly bluer than early-type galaxies with increasing host luminosity. Most of the AGNs with detected hosts are emitting at between 1% and 10% of their estimated Eddington luminosities, but the sensitivity of the technique usually does not extend to the Eddington limit. There are mild correlations among the AGN and host galaxy eigencoefficients, possibly indicating a link between recent star formation and the onset of AGN activity. The catalog of spectral reconstruction parameters is available as an electronic table.

  18. The ecology of carrion decomposition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrion, or the remains of dead animals, is something that most people would like to avoid. It is visually unpleasant, emits foul odors, and may be the source of numerous pathogens. Decomposition of carrion, however, provides a unique opportunity for scientists to investigate how nutrients cycle t...

  19. Scaling up through domain decomposition

    Microsoft Academic Search

    Clemens Pechstein; Robert Scheichl

    2009-01-01

    In this article, we discuss domain decomposition parallel iterative solvers for highly heterogeneous problems of flow and transport in porous media. We are particularly interested in highly unstructured coefficient variation where standard periodic or stochastic homogenization theory is not applicable. When the smallest scale at which the coefficient varies is very small, it is often necessary to scale up the

  20. AVALANCHES, SANDPILES AND TUTTE DECOMPOSITION

    E-print Network

    Gabrielov, Andrei

    AVALANCHES, SANDPILES AND TUTTE DECOMPOSITION Andrei GABRIELOV Department of Geology, Cornell and avalanche models of failure were introduced recently (Bak et al., 1987, and an avalanche of publications properties of an important class of these models, Abelian sandpiles (Dhar, 1990) and Abelian avalanches

  1. Wavelet decomposition of data streams

    E-print Network

    Tian, Qi

    Wavelet decomposition of data streams by Dragana Veljkovic #12;Motivation · Continuous data streams of the original wavelet #12;Discrete wavelet transform · Uses only fixed values for wavelet scales based on powers and surprises #12;Outline · Background · streams · wavelets · sketches · error analysis · Results

  2. ABSTRACT DECOMPOSITION THEOREM AND APPLICATIONS

    E-print Network

    Grossberg, Rami

    of an #0­stable first order theory. (2) K is the class of F a # 0 ­saturated models of a superstable first of locally saturated models of a superstable good dia­ gram D. (5) K is the class of (D, #0)­homogeneous T is superstable and satisfies NDOP, every # # ­saturated model has a decomposition in terms of an independent tree

  3. ABSTRACT DECOMPOSITION THEOREM AND APPLICATIONS

    E-print Network

    Grossberg, Rami

    of an 0-stable first order theory. (2) K is the class of Fa 0 -saturated models of a superstable first of locally saturated models of a superstable good dia- gram D. (5) K is the class of (D, 0)-homogeneous T is superstable and satisfies NDOP, every -saturated model has a decomposition in terms of an independent tree

  4. Algebraic cell decomposition in NC

    Microsoft Academic Search

    Dexter KozenI; Chee-Kang Yap

    1985-01-01

    We give an algorithm to construct a cell decomposition of Rd, including adjacency information, defined by any given set of rational polynomials in d variables. The algorithm runs in single exponential parallel time, and in NC for fixed d. The algorithm extends a recent algorithm of Ben-Or, Kozen, and Reif for deciding the theory of real closed fields.

  5. Cadaver decomposition in terrestrial ecosystems.

    PubMed

    Carter, David O; Yellowlees, David; Tibbett, Mark

    2007-01-01

    A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected microsere. Here we review the processes associated with the introduction of cadaver-derived carbon and nutrients into soil from forensic and ecological settings to show that cadaver decomposition can have a greater, albeit localised, effect on belowground ecology than plant and faecal resources. Cadaveric materials are rapidly introduced to belowground floral and faunal communities, which results in the formation of a highly concentrated island of fertility, or cadaver decomposition island (CDI). CDIs are associated with increased soil microbial biomass, microbial activity (C mineralisation) and nematode abundance. Each CDI is an ephemeral natural disturbance that, in addition to releasing energy and nutrients to the wider ecosystem, acts as a hub by receiving these materials in the form of dead insects, exuvia and puparia, faecal matter (from scavengers, grazers and predators) and feathers (from avian scavengers and predators). As such, CDIs contribute to landscape heterogeneity. Furthermore, CDIs are a specialised habitat for a number of flies, beetles and pioneer vegetation, which enhances biodiversity in terrestrial ecosystems. PMID:17091303

  6. Outpatient management of severe early OHSS by administration of GnRH antagonist in the luteal phase: an observational cohort study

    PubMed Central

    2012-01-01

    Background Management of established severe OHSS requires prolonged hospitalization, occasionally in intensive care units, accompanied by multiple ascites punctures, correction of intravascular fluid volume and electrolyte imbalance. The aim of the present study was to evaluate whether it is feasible to manage women with severe OHSS as outpatients by treating them with GnRH antagonists in the luteal phase. Methods This is a single-centre, prospective, observational, cohort study. Forty patients diagnosed with severe OHSS, five days post oocyte retrieval, were managed as outpatients after administration of GnRH antagonist (0.25?mg) daily from days 5 to 8 post oocyte retrieval, combined with cryopreservation of all embryos. The primary outcome measure was the proportion of patients with severe OHSS, in whom outpatient management was not feasible. Results 11.3% (95% CI 8.3%-15.0%) of patients (40/353) developed severe early OHSS. None of the 40 patients required hospitalization following luteal antagonist administration and embryo cryopreservation. Ovarian volume, ascites, hematocrit, WBC, serum oestradiol and progesterone decreased significantly (P?

  7. Early-type stars observed in the ESO UVES Paranal Observatory Project - IV. Studies of CN, CH+ and CH in the interstellar medium

    NASA Astrophysics Data System (ADS)

    Smoker, J.; Ledoux, C.; Jehin, E.; Keenan, F. P.; Kennedy, M.; Cabanac, R.; Melo, C.

    2014-02-01

    High spectral resolution (˜80 000) and signal-to-noise observations from the Ultraviolet and Visual Echelle Spectrograph Paranal Observatory Project (UVES-POP) are used to study the interstellar molecular lines CN (3874 Å), CH+ (3957, 4232 Å) and CH (3886, 4300 Å) towards 74 O- and B-type stellar sightlines. Additionally, archive data are presented for 140 ELODIE early-type stellar sightlines at R = 42 000, plus 25 FEROS at R = 48 000 and 3 UVES at R > 50 000, mainly in the CH+ (4232 Å) and CH (3886, 4300 Å) transitions. Detection rates are ˜45 per cent for CN and ˜67 per cent for the other lines in the POP sample, and ˜10-15 per cent for CH+ and CH lines in the additional sample. CH and CH+ are well correlated between log[N(CH) cm-2]˜12-14, implying that these clouds are CH+-like CH and not CN-like CH. CH is also very well correlated with Na I D in the range log[N(Na I cm-2]) ˜12.2-14.2. A few sightlines show tentative velocity shifts of ˜2 km s-1 between CH and CH+, which appear to be caused by differences in component strength in blends, and hence do not provide firm evidence for shocks. Finally, we describe a search for 13CH+ in a sightline towards HD 76341. No 13CH+ is detected, placing a limit on the 13CH+ to 12CH+ ratio of ˜0.01. If a formal fit is attempted, the equivalent width ratio in the two isotopes is a factor ˜90 but with large errors.

  8. Spectroscopic Observations of SN 2012fr: A Luminous, Normal Type Ia Supernova with Early High-velocity Features and a Late Velocity Plateau

    NASA Astrophysics Data System (ADS)

    Childress, M. J.; Scalzo, R. A.; Sim, S. A.; Tucker, B. E.; Yuan, F.; Schmidt, B. P.; Cenko, S. B.; Silverman, J. M.; Contreras, C.; Hsiao, E. Y.; Phillips, M.; Morrell, N.; Jha, S. W.; McCully, C.; Filippenko, A. V.; Anderson, J. P.; Benetti, S.; Bufano, F.; de Jaeger, T.; Forster, F.; Gal-Yam, A.; Le Guillou, L.; Maguire, K.; Maund, J.; Mazzali, P. A.; Pignata, G.; Smartt, S.; Spyromilio, J.; Sullivan, M.; Taddia, F.; Valenti, S.; Bayliss, D. D. R.; Bessell, M.; Blanc, G. A.; Carson, D. J.; Clubb, K. I.; de Burgh-Day, C.; Desjardins, T. D.; Fang, J. J.; Fox, O. D.; Gates, E. L.; Ho, I.-T.; Keller, S.; Kelly, P. L.; Lidman, C.; Loaring, N. S.; Mould, J. R.; Owers, M.; Ozbilgen, S.; Pei, L.; Pickering, T.; Pracy, M. B.; Rich, J. A.; Schaefer, B. E.; Scott, N.; Stritzinger, M.; Vogt, F. P. A.; Zhou, G.

    2013-06-01

    We present 65 optical spectra of the Type Ia SN 2012fr, 33 of which were obtained before maximum light. At early times, SN 2012fr shows clear evidence of a high-velocity feature (HVF) in the Si II ?6355 line that can be cleanly decoupled from the lower velocity "photospheric" component. This Si II ?6355 HVF fades by phase -5 subsequently, the photospheric component exhibits a very narrow velocity width and remains at a nearly constant velocity of ~12,000 km s-1 until at least five weeks after maximum brightness. The Ca II infrared triplet exhibits similar evidence for both a photospheric component at v ? 12,000 km s-1 with narrow line width and long velocity plateau, as well as an HVF beginning at v ? 31,000 km s-1 two weeks before maximum. SN 2012fr resides on the border between the "shallow silicon" and "core-normal" subclasses in the Branch et al. classification scheme, and on the border between normal and high-velocity Type Ia supernovae (SNe Ia) in the Wang et al. system. Though it is a clear member of the "low velocity gradient" group of SNe Ia and exhibits a very slow light-curve decline, it shows key dissimilarities with the overluminous SN 1991T or SN 1999aa subclasses of SNe Ia. SN 2012fr represents a well-observed SN Ia at the luminous end of the normal SN Ia distribution and a key transitional event between nominal spectroscopic subclasses of SNe Ia.

  9. Early fluid loading in acute respiratory distress syndrome with septic shock deteriorates lung aeration without impairing arterial oxygenation: a lung ultrasound observational study

    PubMed Central

    2014-01-01

    Introduction The study was designed to assess the impact of fluid loading on lung aeration, oxygenation and hemodynamics in patients with septic shock and acute respiratory distress syndrome (ARDS). Methods During a 1-year period, a prospective observational study was performed in 32 patients with septic shock and ARDS. Cardiorespiratory parameters were measured using Swan Ganz (n?=?29) or PiCCO catheters (n?=?3). Lung aeration and regional pulmonary blood flows were measured using bedside transthoracic ultrasound. Measurements were performed before (T0), at the end of volume expansion (T1) and 40 minutes later (T2), consisting of 1-L of saline over 30 minutes during the first 48 h following onset of septic shock and ARDS. Results Lung ultrasound score increased by 23% at T2, from 13 at baseline to 16 (P?Early fluid loading transitorily improves hemodynamics and oxygenation and worsens lung aeration. Aeration changes can be detected at the bedside by transthoracic lung ultrasound, which may serve as a safeguard against excessive fluid loading. PMID:24887155

  10. Investigating hydrogel dosimeter decomposition by chemical methods

    NASA Astrophysics Data System (ADS)

    Jordan, Kevin

    2015-01-01

    The chemical oxidative decomposition of leucocrystal violet micelle hydrogel dosimeters was investigated using the reaction of ferrous ions with hydrogen peroxide or sodium bicarbonate with hydrogen peroxide. The second reaction is more effective at dye decomposition in gelatin hydrogels. Additional chemical analysis is required to determine the decomposition products.

  11. INTERACTIVE SIMULATION OF FIRE, BURN AND DECOMPOSITION

    E-print Network

    Keyser, John

    INTERACTIVE SIMULATION OF FIRE, BURN AND DECOMPOSITION A Dissertation by ZEKI MELEK Submitted OF FIRE, BURN AND DECOMPOSITION A Dissertation by ZEKI MELEK Submitted to the Office of Graduate Studies Science #12;iii ABSTRACT Interactive Simulation of Fire, Burn and Decomposition. (December 2007) Zeki

  12. Star Formation Rates and Stellar Masses of z = 7-8 Galaxies from IRAC Observations of the WFC3/IR Early Release Science and the HUDF Fields

    NASA Astrophysics Data System (ADS)

    Labbé, I.; González, V.; Bouwens, R. J.; Illingworth, G. D.; Franx, M.; Trenti, M.; Oesch, P. A.; van Dokkum, P. G.; Stiavelli, M.; Carollo, C. M.; Kriek, M.; Magee, D.

    2010-06-01

    We investigate the Spitzer/IRAC properties of 36 z ~ 7 z 850-dropout galaxies and three z ~ 8 Y 098 galaxies derived from deep/wide-area WFC3/IR data of the Early Release Science, the ultradeep HUDF09, and wide-area NICMOS data. We fit stellar population synthesis models to the spectral energy distributions to derive mean redshifts, stellar masses, and ages. The z ~ 7 galaxies are best characterized by substantial ages (>100 Myr) and M/LV ? 0.2. The main trend with decreasing luminosity is that of bluing of the far-UV slope from ? ~ -2.0 to ? ~ -3.0. This can be explained by decreasing metallicity, except for the lowest luminosity galaxies (0.1L* z = 3), where low metallicity and smooth star formation histories (SFHs) fail to match the blue far-UV and moderately red H - [3.6] color. Such colors may require episodic SFHs with short periods of activity and quiescence ("on-off" cycles) and/or a contribution from emission lines. The stellar mass of our sample of z ~ 7 star-forming galaxies correlates with star formation rate (SFR) according to log M* = 8.70(±0.09) + 1.06(±0.10)log SFR, implying that star formation may have commenced at z > 10. No galaxies are found with SFRs much higher or lower than the past averaged SFR suggesting that the typical star formation timescales are probably a substantial fraction of the Hubble time. We report the first IRAC detection of Y 098-dropout galaxies at z ~ 8. The average rest-frame U - V ? 0.3 (AB) of the three galaxies are similar to faint z ~ 7 galaxies, implying similar M/L. The stellar mass density to M UV,AB < -18 is ?*(z = 8) = 1.8+0.7 -1.0 × 106 M sun Mpc-3, following log ?*(z) = 10.6(±0.6) - 4.4(±0.7) log(1 + z) [M sun Mpc-3] over 3 < z < 8. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 11563, 9797. Based on observations with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407. Support for this work was provided by NASA through contract 125790 issued by JPL/Caltech. Based on service mode observations collected at the European Southern Observatory, Paranal, Chile (ESO Program 073.A-0764A). Based on data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  13. Photocatalysis of chloroform decomposition by the hexachlororuthenate(IV) ion.

    PubMed

    Chan, Alissa M; Peña, Laura A; Segura, Rosa E; Auroprem, Ramya; Harvey, Brent M; Brooke, Caroline M; Hoggard, Patrick E

    2013-01-01

    Dissolved hexachlororuthenate(IV) effectively catalyzes the photodecomposition of chloroform to hydrogen chloride and phosgene under near-UV (? > 345 nm) irradiation, whereby RuCl6(2-) is not itself photocatalytically active, but is photochemically transformed into a species that is active, possibly RuCl5 (CHCl3 )(-) . Conversion to a photoactive species during irradiation is consistent with the acceleration of the decomposition rate during the early stages and with the apparent inverse dependence of the decomposition rate on the initial concentration of RuCl6(2-) . The displacement of Cl(-) by CHCl3 in the coordination sphere to create the photoactive species is consistent with the retardation of photodecomposition by both Cl(-) and H2 O. The much smaller photodecomposition rate in CDCl3 suggests that C-H bond dissociation occurs during the primary photochemical event, which is also consistent with the presence of a CHCl3 molecule in the first coordination sphere. PMID:23050803

  14. Effects of decomposition on gunshot wound characteristics: under moderate temperatures with insect activity.

    PubMed

    MacAulay, Lauren E; Barr, Darryl G; Strongman, Doug B

    2009-03-01

    Previous studies document characteristics of gunshot wounds shortly after they were inflicted. This study was conducted to determine if the early stages of decomposition obscure or alter the physical surface characteristics of gunshot wounds, thereby affecting the quantity and quality of information retrievable from such evidence. The study was conducted in August and September, 2005 in Nova Scotia, Canada in forested and exposed environments. Recently killed pigs were used as research models and were shot six times each at three different ranges (contact, 2.5 cm, and 1.5 m). Under these test conditions, the gunshot wounds maintained the characteristics unique to each gunshot range and changes that occurred during decomposition were not critical to the interpretation of the evidence. It was concluded that changes due to decomposition under the conditions tested would not affect the collection and interpretation of gunshot wound evidence until the skin was degraded in the late active or advanced decay stage of decomposition. PMID:19215324

  15. Chunk decomposition contributes to forming new mental representations: An ERP study.

    PubMed

    Zhang, Zhonglu; Xing, Qiang; Li, Hong; Warren, Christopher Michael; Tang, Zhiwen; Che, Jingshang

    2015-06-26

    Whereas previous studies mainly focused on the role of chunk decomposition on how to break impasse in insight occurrence, our study aimed to investigate the role of chunk decomposition in forming new mental representations. For this purpose, the Chinese riddle comprehension task was employed in which the riddle involves either tight or loose chunk decomposition. The event-related potentials (ERPs) were measured after the onset of an answer hint, with which participants were instructed to comprehend the Chinese riddles. The behavioral results showed that participants performed worse on riddle comprehension in tight chunk condition than in loose chunk condition. In addition, we found larger N100 and P300 deflections in the former condition than in the latter condition. These findings suggest that early perceptual processing is crucially required by chunk decomposition, which contributes to forming new mental representations by integrating the perceptual and semantic information. PMID:25957557

  16. Thermal decomposition of furan generates propargyl radicals.

    PubMed

    Vasiliou, AnGayle; Nimlos, Mark R; Daily, John W; Ellison, G Barney

    2009-07-30

    The thermal decomposition of furan has been studied by a 1 mm x 2 cm tubular silicon carbide reactor, C(4)H(4)O + Delta --> products. Unlike previous studies, these experiments are able to identify the initial furan decomposition products. Furan is entrained in either He or Ar carrier gas and is passed through a heated (1600 K) SiC tubular reactor. Furan decomposes during transit through the tubular reactor (approximately 65 micros) and exits to a vacuum chamber. Within one nozzle diameter of leaving the nozzle, the gases cool to less than 50 K, and all reactions cease. The resultant molecular beam is interrogated by photoionization mass spectroscopy as well as infrared spectroscopy. Earlier G2(MP2) electronic structure calculations predicted that furan will thermally decompose to acetylene, ketene, carbon monoxide, and propyne at lower temperatures. At higher temperatures, these calculations forecast that propargyl radical could result. We observe all of these species (see Scheme 1). As the pressure in the tubular reactor is raised, the photoionization mass spectra show clear evidence for the formation of aromatic hydrocarbons. PMID:19719311

  17. Refining signal decomposition for GRETINA detectors

    NASA Astrophysics Data System (ADS)

    Prasher, V. S.; Campbell, C. M.; Cromaz, M.; Crawford, H. L.; Wiens, A.; Lee, I. Y.; Macchiavelli, A. O.; Lister; Merchan, E.; Chowdhury, P.; Radford, D. C.

    2013-04-01

    The reconstruction of the original direction and energy of gamma rays through locating their interaction points in solid state detectors is a crucial evolving technology for nuclear physics, space science and homeland security. New arrays AGATA and GRETINA have been built for nuclear science based on highly segmented germanium crystals. The signal decomposition process fits the observed waveform from each crystal segment with a linear combination of pre-calculated basis signals. This process occurs on an event-by-event basis in real time to extract the position and energy of ?-ray interactions. The methodology for generating a basis of pulse shapes, varying according to the position of the charge generating interactions, is in place. Improvements in signal decomposition can be realized by better modeling the crystals. Specifically, a better understanding of the true impurity distributions, internal electric fields, and charge mobilities will lead to more reliable bases, more precise definition of the interaction points, and hence more reliable tracking. In this presentation we will cover the current state-of-the-art for basis generation and then discuss the sensitivity of the predicted pulse shapes when varying some key parameters.

  18. Climate sensitivity and macronutrient regulation of peat decomposition

    NASA Astrophysics Data System (ADS)

    Marshall, Rachel; Ostle, Nick; McNamara, Niall; Baggs, Elizabeth

    2013-04-01

    Organic soils act as vital global carbon stores maintained in northern latitudes by climate and nutrient limited rates of organic matter decomposition. Peatland decomposition rates are sensitive to climate change, however predicting the magnitude of the microbial respiratory response is complex due to unknown interactions between climate and substrate quality. The nutrient status of peatlands varies widely from mineral rich fens to nutrient poor ombrotrophic bogs, which have the potential to respond differently to climate driven changes in temperature and carbon (C) inputs. In this work we examine the links between peatland macronutrient C, phosphorus (P) and nitrogen (N) stoichiometry, microbial community structure and the microbial response to direct and indirect effects of climate change. Using total soil C:N and C:P ratios to define nutrient gradients in organic soils from Svalbard and Finland we investigated the interaction between the microbial response to temperature and nutrient limitation of decomposition. In organic rich soils from Svalbard we found there was a significant relationship between increasing temperature sensitivity of respiration and decreasing total soil P concentrations. Further investigation of the potential direct link between P limitation of decomposition and increased temperature sensitivity along a minerotrophic-ombroptrophic gradient in Finland was performed using multi-factorial P limitation assays. These showed that despite varying degrees of P limitation across four peatland soils there was no relationship between P limitation and increased temperature sensitivity of soil respiration. Throughout this study we found consistently high temperature sensitivity of decomposition in organic rich soils with Q10 values ranging between 2 to 4.5, indicating potentially higher vulnerability of these C stores to warming than is currently predicted using a globally invariant Q10. Following on from this we examined the interaction between peatland nutrient status and the potential for labile C substrates to stimulate (prime) decomposition of the peat organic matter. Using 13C labelled glucose and hemicellulose compounds we observed significant differences in the amount and rate of microbial substrate use between peats with differing nutrient status. Nutrient addition experiments were used with labelled C substrates to investigate the role of N and P limitation in enhancing or restricting priming effects. This is one of the first studies to use 13C substrates to examine potential priming effects in peat soil and it provides an insight into the importance of priming mechanisms in peat decomposition. This work explicitly links soil microbial responses to temperature and nutrient manipulations with microbial community structure allowing us to observe how microbial communities mediate soil C losses in peat soils. Disentangling the complex interactions between soil microbial community, C and nutrient limitation of decomposition is essential for predicting the vulnerability of different peatland ecosystems to climate driven changes.

  19. Thermal decomposition of a thin AgOx layer generating optical near-field

    NASA Astrophysics Data System (ADS)

    Kolobov, A. V.; Rogalev, A.; Wilhelm, F.; Jaouen, N.; Shima, T.; Tominaga, J.

    2004-03-01

    Thermal decomposition of AgOx thin layers generating optical near field have been studied by Ag LIII edge x-ray absorption near-edge structure. We found that, different from previous assumptions, the starting layer is a mixture of AgO (˜40%) and Ag2O (˜60%). We further observed that thermal decomposition starts at a temperature as low as 50 °C. The decomposition process exhibits three stages and the oxide layer at intermediate stages consists of a mixture of AgO, Ag2O, and metallic Ag with different fractions of each phase. Activation energies of the decomposition of the thin oxide layer have been determined for different decomposition stages, the obtained values being different from that for powder oxides.

  20. GC?×?GC-TOFMS and supervised multivariate approaches to study human cadaveric decomposition olfactive signatures.

    PubMed

    Stefanuto, Pierre-Hugues; Perrault, Katelynn A; Stadler, Sonja; Pesesse, Romain; LeBlanc, Helene N; Forbes, Shari L; Focant, Jean-François

    2015-06-01

    In forensic thanato-chemistry, the understanding of the process of soft tissue decomposition is still limited. A better understanding of the decomposition process and the characterization of the associated volatile organic compounds (VOC) can help to improve the training of victim recovery (VR) canines, which are used to search for trapped victims in natural disasters or to locate corpses during criminal investigations. The complexity of matrices and the dynamic nature of this process require the use of comprehensive analytical methods for investigation. Moreover, the variability of the environment and between individuals creates additional difficulties in terms of normalization. The resolution of the complex mixture of VOCs emitted by a decaying corpse can be improved using comprehensive two-dimensional gas chromatography (GC?×?GC), compared to classical single-dimensional gas chromatography (1DGC). This study combines the analytical advantages of GC?×?GC coupled to time-of-flight mass spectrometry (TOFMS) with the data handling robustness of supervised multivariate statistics to investigate the VOC profile of human remains during early stages of decomposition. Various supervised multivariate approaches are compared to interpret the large data set. Moreover, early decomposition stages of pig carcasses (typically used as human surrogates in field studies) are also monitored to obtain a direct comparison of the two VOC profiles and estimate the robustness of this human decomposition analog model. In this research, we demonstrate that pig and human decomposition processes can be described by the same trends for the major compounds produced during the early stages of soft tissue decomposition. PMID:25910882

  1. Direct and Indirect Effects of UV-B Exposure on Litter Decomposition: A Meta-Analysis

    PubMed Central

    Song, Xinzhang; Peng, Changhui; Jiang, Hong; Zhu, Qiuan; Wang, Weifeng

    2013-01-01

    Ultraviolet-B (UV-B) exposure in the course of litter decomposition may have a direct effect on decomposition rates via changing states of photodegradation or decomposer constitution in litter while UV-B exposure during growth periods may alter chemical compositions and physical properties of plants. Consequently, these changes will indirectly affect subsequent litter decomposition processes in soil. Although studies are available on both the positive and negative effects (including no observable effects) of UV-B exposure on litter decomposition, a comprehensive analysis leading to an adequate understanding remains unresolved. Using data from 93 studies across six biomes, this introductory meta-analysis found that elevated UV-B directly increased litter decomposition rates by 7% and indirectly by 12% while attenuated UV-B directly decreased litter decomposition rates by 23% and indirectly increased litter decomposition rates by 7%. However, neither positive nor negative effects were statistically significant. Woody plant litter decomposition seemed more sensitive to UV-B than herbaceous plant litter except under conditions of indirect effects of elevated UV-B. Furthermore, levels of UV-B intensity significantly affected litter decomposition response to UV-B (P<0.05). UV-B effects on litter decomposition were to a large degree compounded by climatic factors (e.g., MAP and MAT) (P<0.05) and litter chemistry (e.g., lignin content) (P<0.01). Results suggest these factors likely have a bearing on masking the important role of UV-B on litter decomposition. No significant differences in UV-B effects on litter decomposition were found between study types (field experiment vs. laboratory incubation), litter forms (leaf vs. needle), and decay duration. Indirect effects of elevated UV-B on litter decomposition significantly increased with decay duration (P<0.001). Additionally, relatively small changes in UV-B exposure intensity (30%) had significant direct effects on litter decomposition (P<0.05). The intent of this meta-analysis was to improve our understanding of the overall effects of UV-B on litter decomposition. PMID:23818993

  2. Anisotropic Decomposition of Energetic Materials

    SciTech Connect

    Pravica, Michael; Quine, Zachary; Romano, Edward; Bajar, Sean; Yulga, Brian; Yang, Wenge; Hooks, Daniel (UNLV); (CIW); (LANL)

    2008-01-17

    Using a white x-ray synchrotron beam, we have dynamically studied radiation-induced decomposition in single crystalline PETN and TATB. By monitoring the integrated intensity of selected diffraction spots via a CCD x-ray camera as a function of time, we have found that the decomposition rate varies dramatically depending upon the orientation of the crystalline axes relative to polarized x-ray beam and for differing diffracting conditions (spots) within the same crystalline orientation. We suggest that this effect is due to Compton scattering of the polarized x-rays with electron clouds that is dependent upon their relative orientation. This novel effect may yield valuable insight regarding anisotropic detonation sensitivity in energetic materials such as PETN.

  3. Anisotropic decomposition of energetic materials

    SciTech Connect

    Pravica, Michael; Quine, Zachary; Romano, Edward; Bajar, Sean; Yulga, Brian [High Pressure Science and Engineering Center and Department of Physics, University of Nevada Las Vegas, Las Vegas, NV USA, 89154-4002 (United States); Yang Wenge [HP-CAT, Advanced Photon Source, Argonne National Laboratory, Argonne, IL (United States); Hooks, Daniel [Dynamic Experimentation Division (DE-9), Los Alamo National Laboratory, Los Alamos, NM 87545 (United States)

    2007-12-12

    Using a white x-ray synchrotron beam, we have dynamically studied radiation-induced decomposition in single crystalline PETN and TATB. By monitoring the integrated intensity of selected diffraction spots via a CCD x-ray camera as a function of time, we have found that the decomposition rate varies dramatically depending upon the orientation of the crystalline axes relative to polarized x-ray beam and for differing diffracting conditions (spots) within the same crystalline orientation. We suggest that this effect is due to Compton scattering of the polarized x-rays with electron clouds that is dependent upon their relative orientation. This novel effect may yield valuable insight regarding anisotropic detonation sensitivity in energetic materials such as PETN.

  4. Thermooxidative decomposition of oil shales

    Microsoft Academic Search

    Tiit Kaljuvee; Merli Keelmann; Andres Trikkel; Rein Kuusik

    2011-01-01

    The thermooxidative decomposition of four oil shale samples from Estonia, Jordan, Israel and Morocco and one sample of Estonian\\u000a oil shale derivative, semicoke, was studied with the aim to determine the characteristics of the process and the differences\\u000a of it related to the origin of oil shale. The experiments with a Setaram Setsys 1750 thermoanalyzer coupled to a Nicolet 380

  5. Income Sorting: Measurement and Decomposition

    Microsoft Academic Search

    Thomas Davido

    Abstract This paper addresses the measurement of income sorting across jurisdictions and the attribution of sorting to governmental dierences.,Measurement error and dier- ences between transitory and permanent income bias variance decompositions sorting estimates downward,by approximately 50 percent. Adjusted US Census data show an average across Metropolitan Areas (MSAs) of approximately eight percent of income variation explained by dierences,across jurisdictions; approximately

  6. Asymmetric decompositions of abelian groups

    Microsoft Academic Search

    T. O. Banach; I. V. Protasov

    1999-01-01

    A subsetA of an Abelian groupG is said to be asymmetric ifg+S?A for any elementg?G and any infinite symmetric subsetS?G (S=?S). The minimal cardinality of a decomposition of the groupG into asymmetric sets is denoted by ?(G). for any Abelian groupG, the cardinal number ?(G is expressed via the following cardinal invariants: the free rank, the 2-rank, and the cardinality

  7. Logic-based Benders decomposition

    Microsoft Academic Search

    J. N. Hooker; G. Ottosson

    2003-01-01

    .  ?Benders decomposition uses a strategy of ``learning from one's mistakes.'' The aim of this paper is to extend this strategy\\u000a to a much larger class of problems. The key is to generalize the linear programming dual used in the classical method to an\\u000a ``inference dual.'' Solution of the inference dual takes the form of a logical deduction that yields Benders

  8. Phlogopite Decomposition, Water, and Venus

    NASA Technical Reports Server (NTRS)

    Johnson, N. M.; Fegley, B., Jr.

    2005-01-01

    Venus is a hot and dry planet with a surface temperature of 660 to 740 K and 30 parts per million by volume (ppmv) water vapor in its lower atmosphere. In contrast Earth has an average surface temperature of 288 K and 1-4% water vapor in its troposphere. The hot and dry conditions on Venus led many to speculate that hydrous minerals on the surface of Venus would not be there today even though they might have formed in a potentially wetter past. Thermodynamic calculations predict that many hydrous minerals are unstable under current Venusian conditions. Thermodynamics predicts whether a particular mineral is stable or not, but we need experimental data on the decomposition rate of hydrous minerals to determine if they survive on Venus today. Previously, we determined the decomposition rate of the amphibole tremolite, and found that it could exist for billions of years at current surface conditions. Here, we present our initial results on the decomposition of phlogopite mica, another common hydrous mineral on Earth.

  9. FUEL DECOMPOSITION AND FLAME REACTIONS IN CONVERSION OF FUEL NITROGEN TO NOX

    EPA Science Inventory

    The report describes an experimental and analytical research program conducted to provide information on the chemical phenomena involved in the conversion of air and fuel nitrogen to NOx. Under Task 1, Fuel Decomposition, early (preflame) reactions of fuel nitrogen species were i...

  10. Upregulation of Cytokines Is Detected in the Placentas of Cattle Infected with Neospora caninum and Is More Marked Early in Gestation When Fetal Death Is Observed

    Microsoft Academic Search

    Anne Rosbottom; E. Helen Gibney; Catherine S. Guy; Anja Kipar; Robert F. Smith; Pete Kaiser; Alexander J. Trees; Diana J. L. Williams

    2008-01-01

    Received 8 November 2006\\/Returned for modification 30 December 2006\\/Accepted 12 February 2008 The protozoan parasite Neospora caninum causes fetal death after experimental infection of pregnant cattle in early gestation, but the fetus survives a similar infection in late gestation. An increase in Th1-type cytokines in the placenta in response to the presence of the parasite has been implicated as a

  11. Engaging Practitioners in Program Evaluation: A Preliminary Report of Perceptions and Observations of Practitioner-Caregiver Partnerships in Early Intervention. A Program Evaluation Report

    ERIC Educational Resources Information Center

    Bainter, Sue; Marvin, Chris

    2006-01-01

    Background: Many early intervention teams are shifting their service delivery for children with disabilities from a child-focused model to one that focuses on strengthening the competence and confidence of the child's caregivers (parents, childcare providers, preschool teachers). The use of coaching strategies in a primary coach model of service…

  12. Nitrogen Addition Significantly Affects Forest Litter Decomposition under High Levels of Ambient Nitrogen Deposition

    PubMed Central

    Chen, Gang; Peng, Yong; Xiao, Yin-long; Hu, Ting-xing; Zhang, Jian; Li, Xian-wei; Liu, Li; Tang, Yi

    2014-01-01

    Background Forest litter decomposition is a major component of the global carbon (C) budget, and is greatly affected by the atmospheric nitrogen (N) deposition observed globally. However, the effects of N addition on forest litter decomposition, in ecosystems receiving increasingly higher levels of ambient N deposition, are poorly understood. Methodology/Principal Findings We conducted a two-year field experiment in five forests along the western edge of the Sichuan Basin in China, where atmospheric N deposition was up to 82–114 kg N ha–1 in the study sites. Four levels of N treatments were applied: (1) control (no N added), (2) low-N (50 kg N ha–1 year–1), (3) medium-N (150 kg N ha–1 year–1), and (4) high-N (300 kg N ha–1 year–1), N additions ranging from 40% to 370% of ambient N deposition. The decomposition processes of ten types of forest litters were then studied. Nitrogen additions significantly decreased the decomposition rates of six types of forest litters. N additions decreased forest litter decomposition, and the mass of residual litter was closely correlated to residual lignin during the decomposition process over the study period. The inhibitory effect of N addition on litter decomposition can be primarily explained by the inhibition of lignin decomposition by exogenous inorganic N. The overall decomposition rate of ten investigated substrates exhibited a significant negative linear relationship with initial tissue C/N and lignin/N, and significant positive relationships with initial tissue K and N concentrations; these relationships exhibited linear and logarithmic curves, respectively. Conclusions/Significance This study suggests that the expected progressive increases in N deposition may have a potential important impact on forest litter decomposition in the study area in the presence of high levels of ambient N deposition. PMID:24551152

  13. Spinodal decomposition patterns in an isodensity critical binary fluid - Direct-visualization and light-scattering analyses

    Microsoft Academic Search

    P. Guenoun; R. Gastaud; F. Perrot; D. Beysens

    1987-01-01

    A carefully density-matched system of deuterated cyclohexane, cyclohexane, and methanol is used to study the phase-separation process near the critical point of fluid mixtures (spinodal decomposition) without the influence of earth's gravity. The principal mechanisms involved in the phase separation of fluids, and especially the spinodal decomposition, are reviewed, and the experimentally available observations are reported. After recalling the video

  14. Conductimetric determination of decomposition of silicate melts

    NASA Technical Reports Server (NTRS)

    Kroeger, C.; Lieck, K.

    1986-01-01

    A description of a procedure is given to detect decomposition of silicate systems in the liquid state by conductivity measurements. Onset of decomposition can be determined from the temperature curves of resistances measured on two pairs of electrodes, one above the other. Degree of decomposition can be estimated from temperature and concentration dependency of conductivity of phase boundaries. This procedure was tested with systems PbO-B2O3 and PbO-B2O3-SiO2.

  15. Large-scale Structures revealed by Wavelet Decomposition

    E-print Network

    Li-Zhi Fang; Jesus Pando

    1997-01-29

    We present a detailed review of large-scale structure (LSS) study using the discrete wavelet transform (DWT). After describing how one constructs a wavelet decomposition we show how this bases can be used as a complete statistical discription of LSS. Among the topics studied are the the DWT estimation of the probability distribution function; the reconstruction of the power spectrum; the regularization of complex geometry in observational samples; cluster identification; extraction and identification of coherent structures; scale-decomposition of non-Gaussianity, such as spectra of skewnes and kurtosis and scale-scale correlations. These methods are applied to both observational and simulated samples of the QSO Lyman-alpha forests. It is clearly demonstrated that the statistical measures developed using the DWT are needed to distinguish between competing models of structure formation. The DWT also reveals physical features in these distributions not detected before. We conclude with a look towards the future of the use of the DWT in LSS.

  16. Addition of External Organic Carbon and Native Soil Organic Carbon Decomposition: A Meta-Analysis

    PubMed Central

    Zhang, Weidong; Wang, Xiaofeng; Wang, Silong

    2013-01-01

    Background Extensive studies have been conducted to evaluate the effect of external organic Carbon on native soil organic carbon (SOC) decomposition. However, the direction and extent of this effect reported by different authors is inconsistent. Objective The objective was to provide a synthesis of existing data that comprehensively and quantitatively evaluates how the soil chemical properties and incubation conditions interact with additional external organic C to affect the native SOC decomposition. Data Source A meta-analysis was conducted on previously published empirical studies that examined the effect of the addition of external organic carbon on the native SOC decomposition through isotopic techniques. Results and Conclusions The addition of external organic C, when averaged across all studies, enhanced the native SOC decomposition by 26.5%. The soil with higher SOC content and fine texture showed significantly higher priming effects, whereas the soil with higher total nitrogen content showed an opposite trend. The soils with higher C:N ratios had significantly stronger priming effects than those with low C:N ratios. The decomposition of native SOC was significantly enhanced more at early stage of incubation (<15d) than at the later stages (>15d). In addition, the incubation temperature and the addition rate of organic matter significantly influenced the native SOC decomposition in response to the addition of external organic C. PMID:23405095

  17. Sequence of Tissue Responses in the Early Stages of Experimental Allergic Encephalomyelitis (EAE): Immunohistochemical, Light Microscopic, and Ultrastructural Observations in the Spinal Cord

    NASA Technical Reports Server (NTRS)

    DAmelio, Fernando E.; Smith, Marion E.; Eng, Lawrence F.

    1990-01-01

    Experimental allergic encephalomyelitis (EAE) was induced in adult Lewis rats with purified guinea pig CNS myelin and Freund's adjuvant. As soon as the very earliest clinical signs appeared the animals were perfused with fixatives and the spinal cord analyzed by electron microscopy, silver methods, and immunocytochemistry. Our findings suggest that in the early stages of EAE a sequence of events can be traced, although these events frequently overlap. The earliest morphological change appears to be astrocytic edema in both the cell body and processes. Increased amounts of glycogen particles and dispersion of glial filaments are prominent. These changes seem to occur just prior to the time when inflammatory cells begin to penetrate the capillary walls. Invasion of the neuropil mainly by macrophages and lymphocytes closely follows. Both macrophages and microglia seem to participate in phagocytosis of oligodendrocytes and myelin. Demyelination, however, is not a prominent feature at this early stage.

  18. Cumulative funnel plots for the early detection of interoperator variation: retrospective database analysis of observed versus predicted results of percutaneous coronary intervention

    Microsoft Academic Search

    Babu Kunadian; Joel Dunning; Anthony P Roberts; Robert Morley; Darragh Twomey; James A Hall; Andrew G C Sutton; Robert A Wright; Douglas F Muir; Mark A de Belder

    2008-01-01

    Objective To use funnel plots and cumulative funnel plots to compare in-hospital outcome data for operators undertaking percutaneous coronary interventions with predicted results derived from a validated risk score to allow for early detection of variation in performance.Design Analysis of prospectively collected data.Setting Tertiary centre NHS hospital in the north east of England.Participants Five cardiologists carrying out percutaneous coronary interventions

  19. Singular-value decomposition of a tomosynthesis system.

    PubMed

    Burvall, Anna; Barrett, Harrison H; Myers, Kyle J; Dainty, Christopher

    2010-09-27

    Tomosynthesis is an emerging technique with potential to replace mammography, since it gives 3D information at a relatively small increase in dose and cost. We present an analytical singular-value decomposition of a tomosynthesis system, which provides the measurement component of any given object. The method is demonstrated on an example object. The measurement component can be used as a reconstruction of the object, and can also be utilized in future observer studies of tomosynthesis image quality. PMID:20940966

  20. Large-scale SOP minimization using decomposition and functional properties

    Microsoft Academic Search

    Alan Mishchenko; Tsutomu Sasao

    2003-01-01

    In some cases, minimum sum-of-products (SOP) expressions of Boolean functions can be derived by detecting decomposition and observing the functional properties such as unateness, instead of applying the classical minimization algorithms. This paper presents a systematic study of such situations and develops a divide-and-conquer algorithm for SOP minimization, which can dramatically reduce the computational effort, without sacrificing the minimality of

  1. Ozone decomposition in water solutions 

    E-print Network

    Hewes, Cecil Grayson

    1969-01-01

    . . . . . . . . . . . . . 75 III. CBI. iiICAT, OXYGEN DEMAND TEST. . IV. OIONE DECOI'IPOSITION DATA. . . . . V. COD DATA FOH THE CONTINUOUS ABSOHBER- REACTION SYSTEM VITA 78 8$ LIST OF TABLES TABI E PAGE I. OZONE DECOMPOSITION IN MATER SOLUTIONS. . . g4 Il. REACTION...ATER SOLUTIONS OF pH 8. XIII. REACTION RATE CONSTANTS FOR THE D'COMPOSITION OF OZONE IN INTER SOLUTIONS OF pH 8. XIV COD REMOVAL BY OZONE XV. OZONIZATION OF MATER CONTAINIiNG RESIDUAL AMINE. 57 60 LIST OF FIGURES FIGURE 1. FIOW DIAGRAM OF THZ...

  2. Thermal Decomposition of Radiation-Damaged Polystyrene

    SciTech Connect

    J Abrefah GS Klinger

    2000-09-26

    The radiation-damaged polystyrene material (''polycube'') used in this study was synthesized by mixing a high-density polystyrene (''Dylene Fines No. 100'') with plutonium and uranium oxides. The polycubes were used on the Hanford Site in the 1960s for criticality studies to determine the hydrogen-to-fissile atom ratios for neutron moderation during processing of spent nuclear fuel. Upon completion of the studies, two methods were developed to reclaim the transuranic (TRU) oxides from the polymer matrix: (1) burning the polycubes in air at 873 K; and (2) heating the polycubes in the absence of oxygen and scrubbing the released monomer and other volatile organics using carbon tetrachloride. Neither of these methods was satisfactory in separating the TRU oxides from the polystyrene. Consequently, the remaining polycubes were sent to the Hanford Plutonium Finishing Plant (PFP) for storage. Over time, the high dose of alpha and gamma radiation has resulted in a polystyrene matrix that is highly cross-linked and hydrogen deficient and a stabilization process is being developed in support of Defense Nuclear Facility Safety Board Recommendation 94-1. Baseline processes involve thermal treatment to pyrolyze the polycubes in a furnace to decompose the polystyrene and separate out the TRU oxides. Thermal decomposition products from this degraded polystyrene matrix were characterized by Pacific Northwest National Laboratory to provide information for determining the environmental impact of the process and for optimizing the process parameters. A gas chromatography/mass spectrometry (GC/MS) system coupled to a horizontal tube furnace was used for the characterization studies. The decomposition studies were performed both in air and helium atmospheres at 773 K, the planned processing temperature. The volatile and semi-volatile organic products identified for the radiation-damaged polystyrene were different from those observed for virgin polystyrene. The differences were in the n umber of organic species generated and their concentrations.

  3. Evaluating litter decomposition in earth system models with long-term litterbag experiments: an example using the Community Land Model version 4 (CLM4).

    PubMed

    Bonan, Gordon B; Hartman, Melannie D; Parton, William J; Wieder, William R

    2013-03-01

    Decomposition is a large term in the global carbon budget, but models of the earth system that simulate carbon cycle-climate feedbacks are largely untested with respect to litter decomposition. We tested the litter decomposition parameterization of the community land model version 4 (CLM4), the terrestrial component of the community earth system model, with data from the long-term intersite decomposition experiment team (LIDET). The LIDET dataset is a 10-year study of litter decomposition at multiple sites across North America and Central America. We performed 10-year litter decomposition simulations comparable with LIDET for 9 litter types and 20 sites in tundra, grassland, and boreal, conifer, deciduous, and tropical forest biomes using the LIDET-provided climatic decomposition index to constrain temperature and moisture effects on decomposition. We performed additional simulations with DAYCENT, a version of the CENTURY model, to ask how well an established ecosystem model matches the observations. The results show large discrepancy between the laboratory microcosm studies used to parameterize the CLM4 litter decomposition and the LIDET field study. Simulated carbon loss is more rapid than the observations across all sites, and nitrogen immobilization is biased high. Closer agreement with the observations requires much lower decomposition rates, obtained with the assumption that soil mineral nitrogen severely limits decomposition. DAYCENT better replicates the observations, for both carbon mass remaining and nitrogen, independent of nitrogen limitation. CLM4 has low soil carbon in global earth system simulations. These results suggest that this bias arises, in part, from too rapid litter decomposition. More broadly, the terrestrial biogeochemistry of earth system models must be critically tested with observations, and the consequences of particular model choices must be documented. Long-term litter decomposition experiments such as LIDET provide a real-world process-oriented benchmark to evaluate models. PMID:23504851

  4. Thermal decomposition of mercuric sulfide

    SciTech Connect

    Leckey, J.H.; Nulf, L.E.

    1994-10-28

    The rate of thermal decomposition of mercuric sulfide (HgS) has been measured at temperatures from 265 to 345 C. These data have been analyzed using a first-order chemical reaction model for the time dependence of the reaction and the Arrhenius equation for the temperature dependence of the rate constant. Using this information, the activation energy for the reaction was found to be 55 kcal/mol. Significant reaction vessel surface effects obscured the functional form of the time dependence of the initial portion of the reaction. The data and the resulting time-temperature reaction-rate model were used to predict the decomposition rate of HgS as a function of time and temperature in thermal treatment systems. Data from large-scale thermal treatment studies already completed were interpreted in terms of the results of this study. While the data from the large-scale thermal treatment studies were consistent with the data from this report, mass transport effects may have contributed to the residual amount of mercury which remained in the soil after most of the large-scale runs.

  5. Comparison of Serological Response to Doxycycline versus Benzathine Penicillin G in the Treatment of Early Syphilis in HIV-Infected Patients: A Multi-Center Observational Study

    PubMed Central

    Tsai, Jen-Chih; Lin, Yu-Huei; Lu, Po-Liang; Shen, Ni-Jiin; Yang, Chia-Jui; Lee, Nan-Yao; Tang, Hung-Jen; Liu, Yuag-Meng; Huang, Wen-Chi; Lee, Chen-Hsiang; Ko, Wen-Chien; Chen, Yen-Hsu; Lin, Hsi-Hsun; Chen, Tun-Chieh; Hung, Chien-Ching

    2014-01-01

    Background While doxycycline is recommended as an alternative treatment of syphilis in patients with penicillin allergy or intolerance, clinical studies to compare serological response to doxycycline versus benzathine penicillin in treatment of early syphilis among HIV-infected patients remain sparse. Methods We retrospectively reviewed the medical records of HIV-infected patients with early syphilis who received doxycycline 100 mg twice daily for 14 days (doxycycline group) and those who received 1 dose of benzathine penicillin (2.4 million units) (penicillin group) between 2007 and 2013. Serological responses defined as a decline of rapid plasma reagin titer by 4-fold or greater at 6 and 12 months of treatment were compared between the two groups. Results During the study period, 123 and 271 patients in the doxycycline and penicillin group, respectively, completed 6 months or longer follow-up. Ninety-one and 271 patients in the doxycycline and penicillin group, respectively, completed 12 months or longer follow-up. Clinical characteristics were similar between the two groups, except that, compared with penicillin group, doxycycline group had a lower proportion of patients with secondary syphilis (65.4% versus 41.5%, P<0.0001) and a higher proportion of patients with early latent syphilis (25.3% versus 49.6%, P<0.0001). No statistically significant differences were found in the serological response rates to doxycycline versus benzathine penicillin at 6 months (63.4% versus 72.3%, P?=?0.075) and 12 months of treatment (65.9% versus 68.3%, P?=?0.681). In multivariate analysis, secondary syphilis, but not treatment regimen, was consistently associated with serological response at 6 and 12 months of follow-up. Conclusions The serological response rates to a 14-day course of doxycycline and a single dose of benzathine penicillin were similar in HIV-infected patients with early syphilis at 6 and 12 months of follow-up. Patients with secondary syphilis were more likely to achieve serological response than those with other stages. PMID:25310367

  6. Generalized covariation and extended Fukushima decompositions for Banach valued processes.

    E-print Network

    Paris-Sud XI, Université de

    Generalized covariation and extended Fukushima decompositions for Banach valued processes corresponding results when B = C([-, 0]) and X = X(·). This will consitute a significant Fukushima decomposition random variables, Malliavin calculus, Generalized Fukushima decomposition. LUISS Guido Carli - Libera

  7. Kinetic modelling of the thermal decomposition of ettringite into metaettringite

    E-print Network

    Boyer, Edmond

    1 Kinetic modelling of the thermal decomposition of ettringite into metaettringite J. Pourchez recent insights into thermal stability and decomposition mechanisms of ettringite, a lack of knowledge isothermal conditions. Keywords: ettringite, metaettringite, thermal decomposition, kinetic modelling. 1

  8. Tracking the Consequences of Morpho-Orthographic Decomposition Using ERPs

    PubMed Central

    Morris, Joanna; Grainger, Jonathan; Holcomb, Phillip J.

    2013-01-01

    We examined the effects of morpho-orthographic decomposition on complex word processing using a combination of masked priming and ERP recordings. The process of morpho-orthographic decomposition was primed by the prior presentation of complex non-words (formed by the combination a legal stem and legal affix, e.g. huntity, cornity, scanity) as prime stimuli. Targets were semantically transparent complex words (e.g. hunter), semantically opaque pseudocomplex words (e.g. corner), and simplex words (e.g. scandal) that contained the same stem as primes or a different stem (e.g., huntity-hunter vs. farmity-hunter). We found a large early (150–200 ms) priming effect for transparent complex words only, followed by widely distributed priming effects between 200 and 300 ms and more spatially focused N400 priming effects for all types of target. Furthermore, in the 150–200 ms time-window, the ERP waveforms generated by pseudocomplex words patterned with those of complex words, both of which generated less negative-going waveforms compared with simplex words. In the N400 time-window, on the other hand, complex words differed from both pseudocomplex and simplex words. The results provide further support for early morpho-orthographic segmentation processes that operate independently of semantic transparency, and suggest that the output of these processes only affects the subsequent processing of truly complex words. PMID:23872217

  9. Response of early Ruppia cirrhosa litter breakdown to nutrient addition in a coastal lagoon affected by agricultural runoff

    NASA Astrophysics Data System (ADS)

    Menéndez, Margarita

    2009-05-01

    The response of early Ruppia cirrhosa Petagna (Grande) litter decomposition to external nitrogen and phosphorus availability in La Tancada (Ebro River, NE Spain), a coastal lagoon that receives agricultural freshwater runoff from rice fields has been examined. Recently abscised dead R. cirrhosa stems were collected and 25 g of fresh weight was placed in litter bags with a mesh size of 100 ?m and 1 mm. These bags were fertilised by adding nitrogen (N), a mixture of nitrogen plus phosphorus (N + P), or phosphorus (P), or were left untreated (CT). Macroinvertebrates were retrieved from the bags and the ash-free dry weight, and carbon, and N and P content of the remaining plant material were measured after 0, 3, 7, 14, 22 and 32 days. Litter decomposition rates, k (day -1), were estimated using a simple exponential model. Litter decay was clearly accelerated by the addition of P in the fine (100 ?m) litter bags (0.042), but when N was added alone (0.0099) the decomposition rate was lower than in the CT treatments (0.022). No significant difference was observed between the N (0.0099-0.018) and N + P (0.0091-0.015) treatments in either the fine or the coarse (1 mm) litter bags. These results could be attributed to the relatively high availability of external (environmental) and internal (detritus contents) N. No significant effect of macro invertebrates was observed in the CT treatment or under N or P or N + P addition. The ratio between the decomposition rates in coarse and fine litter bags (k c/k f) was lower in disturbed Tancada lagoon (0.82) than in Cesine lagoon (2.11), a similar Mediterranean coastal water body with almost pristine conditions. These results indicate that, in addition to data on macroinvertebrate community structure, decomposition rates could also be used to assess water quality in coastal lagoons.

  10. English and Turkish Pupils' Understanding of Decomposition

    ERIC Educational Resources Information Center

    Cetin, Gulcan

    2007-01-01

    This study aimed to describe seventh grade English and Turkish students' levels of understanding of decomposition. Data were analyzed descriptively from the students' written responses to four diagnostic questions about decomposition. Results revealed that the English students had considerably higher sound understanding and lower no understanding…

  11. 9 CFR 354.131 - Decomposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Products 2 2010-01-01 2010-01-01 false Decomposition. 354.131 Section 354.131 Animals and Animal Products...Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of rabbits deleteriously affected by...

  12. Implementation of Large Neural Networks using Decomposition

    Microsoft Academic Search

    H. Selvaraj; H. Niewiadomski; P. Buciak; M. Pleban; P. Sapiecha; T. Luba; V. Muthukumar

    The article presents methods of dealing with huge data in the domain of neural networks. The decomposition of neural networks is introduced and its efficiency is proved by the authors' experiments. The examinations of the effectiveness of argument reduction in the above filed, are presented. Authors indicate, that decomposition is cap a- ble of reducing the size and the complexity

  13. Texture segmentation using hierarchical wavelet decomposition

    Microsoft Academic Search

    Ezzatollah Salari; Z. Ling

    1995-01-01

    This paper presents a texture segmentation algorithm based on a hierarchical wavelet decomposition. Using Daubechies four-tap filter, an original image is decomposed into three detail images and one approximate image. The decomposition can be recursively applied to the approximate image to generate a lower resolution of the pyramid. The segmentation starts at the lowest resolution using the K-means clustering scheme

  14. Parallelizing molecular dynamics using spatial decomposition

    Microsoft Academic Search

    Terry W. Clark; R. von Hanxleden; J. A. McCammon; L. R. Scott

    1994-01-01

    Several algorithms have been used for parallel molecular dynamics, including the replicated algorithm and those based on spatial decompositions. The replicated algorithm stores the entire system's coordinates and forces at each processor, and therefore has a low overhead in maintaining the data distribution. Spatial decompositions distribute the data, providing better locality and scalability with respect to memory and computation. We

  15. Solving multiple criteria problems by interactive decomposition

    Microsoft Academic Search

    Rafael Lazimy

    1986-01-01

    An interactive decomposition method is developed for solving the multiple criteria (MC) problem. Based on nonlinear programming duality theory, the MC problem is decomposed into a series of subproblems and relaxed master problems. Each subproblem is a bicriterion problem, and each relaxed master problem is a standard linear program. The prime objective of the decomposition is to simplify and facilitate

  16. Chinese Orthographic Decomposition and Logographic Structure

    ERIC Educational Resources Information Center

    Cheng, Chao-Ming; Lin, Shan-Yuan

    2013-01-01

    "Chinese orthographic decomposition" refers to a sense of uncertainty about the writing of a well-learned Chinese character following a prolonged inspection of the character. This study investigated the decomposition phenomenon in a test situation in which Chinese characters were repeatedly presented in a word context and assessed…

  17. Balanced 0 1 Matrices Part I: Decomposition

    E-print Network

    Cornuejols, Gerard P.

    Balanced 0 1 Matrices Part I: Decomposition Michele Conforti Gerard Cornuejols y Ajai Kapoor z and Kristina Vuskovic x revised September 2000 Abstract A 0 1 matrix is balanced if, in every square submatrix extends the decomposition of balanced 0 1 matrices obtained by Conforti, Cornuejols and Rao to the class

  18. Surface Mapping Using Consistent Pants Decomposition

    Microsoft Academic Search

    Xianfeng Gu; Hong Qin; Xin Li

    2009-01-01

    óSurface mapping is fundamental to shape computing and various downstream applications. This paper develops a pants decomposition framework for computing maps between surfaces with arbitrary topologies. The framework rst conducts pants decomposition on both surfaces to segment them into consistent sets of pants patches (a pants patch is intuitively dened as a genus- zero surface with three boundaries), then composes

  19. Modeling Northern Peatland Decomposition and Peat

    E-print Network

    Moore, Tim

    Modeling Northern Peatland Decomposition and Peat Accumulation Steve Frolking,1 * Nigel T. Roulet,2´al, Quebec, H3C 3J7, Canada ABSTRACT To test the hypothesis that long-term peat accumula- tion is related to contemporary carbon flux dynamics, we present the Peat Decomposition Model (PDM), a new model of long-term peat

  20. Multiresolution Path Planning Via Sector Decompositions

    E-print Network

    Tsiotras, Panagiotis

    Multiresolution Path Planning Via Sector Decompositions Compatible to On-Board Sensor Data that includes actual path length along with a risk-induced metric. We use a multi-resolution cell decomposition or popup threats. Several multi-resolution or hierarchical algorithms have been proposed in the literature

  1. Tiling Models for Spatial Decomposition in AMTRAN

    Microsoft Academic Search

    J C Compton; C J Clouse

    2005-01-01

    Effective spatial domain decomposition for discrete ordinate (S{sub n}) neutron transport calculations has been critical for exploiting massively parallel architectures typified by the ASCI White computer at Lawrence Livermore National Laboratory. A combination of geometrical and computational constraints has posed a unique challenge as problems have been scaled up to several thousand processors. Carefully scripted decomposition and corresponding execution algorithms

  2. Spectral decomposition of the Renyi map

    Microsoft Academic Search

    I. Antoniou; S. Tasaki

    1993-01-01

    The authors construct a generalized spectral decomposition of the Frobenius-Perron operator of the general beta -adic Renyi map using a general iterative operator method applicable in principle to any mixing dynamical system. They also explicitly define appropriate rigged Hilbert spaces, which provide mathematical meaning to the formally obtained spectral decomposition. The explicit construction of the eigenvalues and eigenvectors allows one

  3. Multichannel Electrocardiogram Decomposition Using Periodic Component Analysis

    Microsoft Academic Search

    Reza Sameni; Christian Jutten; Mohammad B. Shamsollahi

    2008-01-01

    In this letter, we propose the application of the generalized eigenvalue decomposition for the decomposition of multichannel electrocardiogram (ECG) recordings. The proposed method uses a modified version of a previously presented measure of periodicity and a phase-wrapping of the RR-interval, for extracting the ldquomost periodicrdquo linear mixtures of a recorded dataset. It is shown that the method is an improved

  4. Graph decomposition of slim graphs Raphael Yuster

    E-print Network

    Yuster, Raphael

    Graph decomposition of slim graphs Yair Caro Raphael Yuster Abstract A Graph G = (V, E) is called s and no edge of ES connects a vertex from A and a vertex from B. k-slim graphs contain, in particular, the graphs with tree-width k. In this paper we give an algorithm solving the H-decomposition problem

  5. Combined MIPAS (airborne/satellite), CALIPSO and in situ study on large potential NAT particles observed in early Arctic winter stratosphere in December 2011

    NASA Astrophysics Data System (ADS)

    Woiwode, Wolfgang; Höpfner, Michael; Pitts, Michael; Poole, Lamont; Oelhaf, Hermann; Molleker, Sergej; Borrmann, Stephan; Ebersoldt, Andreas; Frey, Wiebke; Gulde, Thomas; Maucher, Guido; Piesch, Christof; Sartorius, Christian; Orphal, Johannes

    2015-04-01

    The understanding of the characteristics of large HNO3-containing particles (potential 'NAT-rocks') involved in vertical redistribution of HNO3 in the polar winter stratosphere is limited due to the difficult accessibility of these particles by observations. While robust polar stratospheric cloud (PSC) classification schemes exist for observations by the space-borne lidar aboard CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) as well as for the passive mid-infrared limb observations by MIPAS (Michelson Interferometer for Passive Atmospheric Sounding), these observations are hardly exploited for the detection of large (diameter >10 ?m) NAT particles. This is due to the facts that these particles have low overall number densities, resulting in weak detectable signatures, and that the physical characteristics of these particles (i.e. shape, morphology, HNO3-content and optical characteristics) are uncertain. We investigate collocated and complementary observations of a low-density potential large NAT particle field by the space-borne instruments CALIPSO and MIPAS-ENVISAT as well as the airborne observations by the limb-sounder MIPAS-STR and the in situ particle probe FSSP-100 (Forward Scattering Spectrometer Probe 100) aboard the high-altitude aircraft Geophysica. The observations aboard the Geophysica on 11 December 2011 associated to ESSenCe (ESa Sounder Campaign 2011) provided us the unique opportunity to study in detail the lower boundary region of a PSC where large potential NAT particles (>20 ?m in diameter) were detected in situ. We analyse the ambient temperatures and gas-phase composition (HNO3 and H2O), the signatures of the observed particles in the CALIPSO and MIPAS observations, the HNO3-content of these particles suggested by the FSSP-100 and MIPAS-STR observations, and focus on the spectral fingerprint of these particles in the MIPAS-STR observations. While the spectral characterisation of the observed particles is subject of ongoing work, our results support that these particles consist of NAT and that the particle shape plays a crucial role.

  6. Multilinear operators for higher-order decompositions.

    SciTech Connect

    Kolda, Tamara Gibson

    2006-04-01

    We propose two new multilinear operators for expressing the matrix compositions that are needed in the Tucker and PARAFAC (CANDECOMP) decompositions. The first operator, which we call the Tucker operator, is shorthand for performing an n-mode matrix multiplication for every mode of a given tensor and can be employed to concisely express the Tucker decomposition. The second operator, which we call the Kruskal operator, is shorthand for the sum of the outer-products of the columns of N matrices and allows a divorce from a matricized representation and a very concise expression of the PARAFAC decomposition. We explore the properties of the Tucker and Kruskal operators independently of the related decompositions. Additionally, we provide a review of the matrix and tensor operations that are frequently used in the context of tensor decompositions.

  7. Warming and Nitrogen Addition Increase Litter Decomposition in a Temperate Meadow Ecosystem

    PubMed Central

    Gong, Shiwei; Guo, Rui; Zhang, Tao; Guo, Jixun

    2015-01-01

    Background Litter decomposition greatly influences soil structure, nutrient content and carbon sequestration, but how litter decomposition is affected by climate change is still not well understood. Methodology/Principal Findings A field experiment with increased temperature and nitrogen (N) addition was established in April 2007 to examine the effects of experimental warming, N addition and their interaction on litter decomposition in a temperate meadow steppe in northeastern China. Warming, N addition and warming plus N addition reduced the residual mass of L. chinensis litter by 3.78%, 7.51% and 4.53%, respectively, in 2008 and 2009, and by 4.73%, 24.08% and 16.1%, respectively, in 2010. Warming, N addition and warming plus N addition had no effect on the decomposition of P. communis litter in 2008 or 2009, but reduced the residual litter mass by 5.58%, 15.53% and 5.17%, respectively, in 2010. Warming and N addition reduced the cellulose percentage of L. chinensis and P. communis, specifically in 2010. The lignin percentage of L. chinensis and P. communis was reduced by warming but increased by N addition. The C, N and P contents of L. chinensis and P. communis litter increased with time. Warming and N addition reduced the C content and C:N ratios of L. chinensisand P. communis litter, but increased the N and P contents. Significant interactive effects of warming and N addition on litter decomposition were observed (P<0.01). Conclusion/Significance The litter decomposition rate was highly correlated with soil temperature, soil water content and litter quality. Warming and N addition significantly impacted the litter decomposition rate in the Songnen meadow ecosystem, and the effects of warming and N addition on litter decomposition were also influenced by the quality of litter. These results highlight how climate change could alter grassland ecosystem carbon, nitrogen and phosphorus contents in soil by influencing litter decomposition. PMID:25774776

  8. Kinetics and mechanism of the alkaline decomposition of hexathionate ion.

    PubMed

    Pan, Changwei; Liu, Yang; Horváth, Attila K; Wang, Zhen; Hu, Ying; Ji, Chen; Zhao, Yuemin; Gao, Qingyu

    2013-04-11

    The alkaline decomposition of hexathionate has been investigated by high-performance liquid chromatography monitoring the concentration of polythionates (such as hexathionate, pentathionate, and tetrathionate) and that of thiosulfate simultaneously in buffered medium at a constant ionic strength. As a major final product, unlike in the case of the alkaline decomposition of tetrathionate and pentathionate, a significant amount of sulfur deposition was also observed. Nevertheless, the chromatograms clearly suggested that heptathionate also appears as a key intermediate in a detectable amount during the course of the reaction. On the basis of these observations an 11-step kinetic model with 9 fitted and 4 fixed rate coefficients is suggested to take all of the most important characteristics of the decomposition into account. The proposed model includes the well-known thiosulfate-assisted sulfur chain, increasing pathways for tetrathionate and pentathionate along with their rate coefficients, but among them that of the thiosulfate-assisted rearrangement of pentathionate has not been reported yet. Having these kinetic parameters in hand reveals a reasonable trend of these rate coefficients against the length of the sulfur chain, suggesting that the attack of the nucleophilic agents like hydroxide, thiosulfate, and sulfite ions is determined by the electron density in the vicinity of the given sulfur atom. PMID:23547768

  9. Mon. Not. R. Astron. Soc. (2007) doi:10.1111/j.1365-2966.2007.12487.x Observational evidence for AGN feedback in early-type galaxies

    E-print Network

    Thomas, Daniel

    2007-01-01

    visual inspection which produces a sample that is not biased against recent star formation and nuclear understood, and compelling observational evidence for its mere existence is still missing. In search

  10. Symptoms during the Menopausal Transition and Early Postmenopause and their Relation to Endocrine Levels over Time: Observations from the Seattle Midlife Women's Health Study

    E-print Network

    Percival, Don

    Levels over Time: Observations from the Seattle Midlife Women's Health Study Nancy Fugate Woods, RN, Ph in sexual desire1 . In the post Women's Health Initiative era, clinicians and researchers search for new

  11. Radiation-Induced Decomposition of PETN and TATB under Extreme Conditions

    SciTech Connect

    Giefers, Hubertus; Pravica, Michael (UNLV)

    2008-11-03

    We conducted a series of experiments investigating decomposition of secondary explosives PETN and TATB at varying static pressures and temperatures using synchrotron radiation. As seen in our earlier work, the decomposition rate of TATB at ambient temperature slows systematically with increasing pressure up to at least 26 GPa but varies little with pressure in PETN at ambient temperature up to 15.7 GPa, yielding important information pertaining to the activation complex volume in both cases. We also investigated the radiation-induced decomposition rate as a function of temperature at ambient pressure and 26 GPa for TATB up to 403 K, observing that the decomposition rate increases with increasing temperature as expected. The activation energy for the TATB reaction at ambient temperature was experimentally determined to be 16 {+-} 3 kJ/mol.

  12. Metallo-organic decomposition films

    NASA Technical Reports Server (NTRS)

    Gallagher, B. D.

    1985-01-01

    A summary of metallo-organic deposition (MOD) films for solar cells was presented. The MOD materials are metal ions compounded with organic radicals. The technology is evolving quickly for solar cell metallization. Silver compounds, especially silver neodecanoate, were developed which can be applied by thick-film screening, ink-jet printing, spin-on, spray, or dip methods. Some of the advantages of MOD are: high uniform metal content, lower firing temperatures, decomposition without leaving a carbon deposit or toxic materials, and a film that is stable under ambient conditions. Molecular design criteria were explained along with compounds formulated to date, and the accompanying reactions for these compounds. Phase stability and the other experimental and analytic results of MOD films were presented.

  13. A global HMX decomposition model

    SciTech Connect

    Hobbs, M.L.

    1996-12-01

    HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) decomposes by competing reaction pathways to form various condensed and gas-phase intermediate and final products. Gas formation is related to the development of nonuniform porosity and high specific surface areas prior to ignition in cookoff events. Such thermal damage enhances shock sensitivity and favors self-supported accelerated burning. The extent of HMX decomposition in highly confined cookoff experiments remains a major unsolved experimental and modeling problem. The present work is directed at determination of global HMX kinetics useful for predicting the elapsed time to thermal runaway (ignition) and the extent of decomposition at ignition. Kinetic rate constants for a six step engineering based global mechanism were obtained using gas formation rates measured by Behrens at Sandia National Laboratories with his Simultaneous Modulated Beam Mass Spectrometer (STMBMS) experimental apparatus. The six step global mechanism includes competition between light gas (H[sub 2]Awe, HCN, CO, H[sub 2]CO, NO, N[sub 2]Awe) and heavy gas (C[sub 2]H[sub 6]N[sub 2]Awe and C[sub 4]H[sub 10]N0[sub 2]) formation with zero order sublimation of HMX and the mononitroso analog of HMX (mn-HMX), C[sub 4]H[sub 8]N[sub 8]Awe[sub 7]. The global mechanism was applied to the highly confined, One Dimensional Time to eXplosion (ODTX) experiment and hot cell experiments by suppressing the sublimation of HMX and mn-HMX. An additional gas-phase reaction was also included to account for the gas-phase reaction of N[sub 2]Awe with H[sub 2]CO. Predictions compare adequately to the STMBMS data, ODTX data, and hot cell data. Deficiencies in the model and future directions are discussed.

  14. Ocean Models and Proper Orthogonal Decomposition

    NASA Astrophysics Data System (ADS)

    Salas-de-Leon, D. A.

    2007-05-01

    The increasing computational developments and the better understanding of mathematical and physical systems resulted in an increasing number of ocean models. Long time ago, modelers were like a secret organization and recognize each other by using secret codes and languages that only a select group of people was able to recognize and understand. The access to computational systems was reduced, on one hand equipment and the using time of computers were expensive and restricted, and on the other hand, they required an advance computational languages that not everybody wanted to learn. Now a days most college freshman own a personal computer (PC or laptop), and/or have access to more sophisticated computational systems than those available for research in the early 80's. The resource availability resulted in a mayor access to all kind models. Today computer speed and time and the algorithms does not seem to be a problem, even though some models take days to run in small computational systems. Almost every oceanographic institution has their own model, what is more, in the same institution from one office to the next there are different models for the same phenomena, developed by different research member, the results does not differ substantially since the equations are the same, and the solving algorithms are similar. The algorithms and the grids, constructed with algorithms, can be found in text books and/or over the internet. Every year more sophisticated models are constructed. The Proper Orthogonal Decomposition is a technique that allows the reduction of the number of variables to solve keeping the model properties, for which it can be a very useful tool in diminishing the processes that have to be solved using "small" computational systems, making sophisticated models available for a greater community.

  15. Strain localization driven by thermal decomposition during seismic shear

    NASA Astrophysics Data System (ADS)

    Platt, J. D.; Brantut, N.; Rice, J. R.

    2011-12-01

    De Paola et al. [2008] analyzed a series of faults in the Northern Apennines, Italy, hosted in anhydrite and dolomite rocks. They found a highly localized band of less than 100 microns, contained within a broader damage zone. Recent High-Velocity Friction (HVF) experiments on kaolinite-bearing gouge samples (Brantut et al. [2008]) have also shown extreme localization in samples undergoing thermal decomposition. They performed microstructural analysis on HVF samples and found an "ultralocalized deformation zone", less than ten microns wide, interpreted to be the main slipping zone in the experiment. By measuring relative humidity in the sample chamber they were also able to observe the thermal dehydration of kaolinite. These laboratory and field observations indicate that straining is extremely localized in fault materials where thermal decomposition reactions may occur. During thermal decomposition reactions pore fluid is released, leading to increases in pore pressure, and a corresponding drop in frictional heating. The reactions are endothermic, so heat is also absorbed as the reactions progress. Previous work by Sulem and Famin [2009] has investigated how these effects influence the evolution of pore pressure and temperature in a uniformly sheared gouge layer. They found that accounting for thermal decomposition reactions leads to significant pore pressure increases, and that the endothermic nature of the reaction acts to cap the maximum temperature achieved. In previous work (Platt, Rudnicki and Rice [2010]) we investigated strain localization using a model for shearing of a fluid-saturated gouge material, finding a formula for the localized zone width as a function of physical properties of the gouge. We now extend this model to include thermal decomposition. Using linear stability methods and an idealized reaction kinetic we infer a new localized zone width when decomposition is accounted for. Numerical simulations then allow us to compare this prediction to results obtained using a realistic Arrhenius kinetic relation for the reaction. We find qualitative agreement between our two methods and find that thermal decomposition is very important when attempting to predict the severity of strain localization. The presence of the reaction localizes the deformation to zones as narrow as a few microns. Reaction-driven, strain localization leads to dramatic dynamic weakening when the fault material reaches a critical reaction temperature, suggesting that thermal decomposition plays an important role in large-scale earthquake mechanics. Furthermore, as reactive material is depleted during the rupture, the localized zone migrates across the fault, towards unreacted material. Finally we use our model to investigate earthquakes occurring at different depths. We know that ambient temperature and compressive stresses increase with depth. Thus, deeper earthquakes begin closer to the critical reaction temperature and experience more frictional heating. We systematically change the ambient temperature and compressive stress in our model, allowing us to compare events occurring at different depths, and make connections between observations in HVF experiments and seismic events.

  16. Insights from letter position dyslexia on morphological decomposition in reading

    PubMed Central

    Friedmann, Naama; Gvion, Aviah; Nisim, Roni

    2015-01-01

    We explored morphological decomposition in reading, the locus in the reading process in which it takes place and its nature, comparing different types of morphemes. We assessed these questions through the analysis of letter position errors in readers with letter position dyslexia (LPD). LPD is a selective impairment to letter position encoding in the early stage of word reading, which results in letter migrations (such as reading “cloud” for “could”). We used the fact that migrations in LPD occur mainly in word-interior letters, whereas exterior letters rarely migrate. The rationale was that if morphological decomposition occurs prior to letter position encoding and strips off affixes, word-interior letters adjacent to an affix (e.g., signs-signs) would become exterior following affix-stripping and hence exhibit fewer migrations. We tested 11 Hebrew readers with developmental LPD and 1 with acquired LPD in 6 experiments of reading aloud, lexical decision, and comprehension, at the single word and sentence levels (compared with 25 age-matched control participants). The LPD participants read a total of 12,496 migratable words. We examined migrations next to inflectional, derivational, or bound function morphemes compared with migrations of exterior letters. The results were that root letters adjacent to inflectional and derivational morphemes were treated like middle letters, and migrated frequently, whereas root letters adjacent to bound function morphemes patterned with exterior letters, and almost never migrated. Given that LPD is a pre-lexical deficit, these results indicate that morphological decomposition takes place in an early, pre-lexical stage. The finding that morphologically complex nonwords showed the same patterns indicates that this decomposition is structurally, rather than lexically, driven. We suggest that letter position encoding takes place before morphological analysis, but in some cases, as with bound function morphemes, the complex word is re-analyzed as two separate words. In this reanalysis, letter positions in each constituent word are encoded separately, and hence the exterior letters of the root are treated as exterior and do not migrate.

  17. Sustaining effect of soil warming on organic matter decomposition

    NASA Astrophysics Data System (ADS)

    Hou, Ruixing; Ouyang, Zhu; Dorodnikov, Maxim; Wilson, Glenn; Kuzyakov, Yakov

    2015-04-01

    Global warming affects various parts of carbon (C) cycle including acceleration of soil organic matter (SOM) decomposition with strong feedback to atmospheric CO2 concentration. Despite many soil warming studies showed changes of microbial community structure, only very few were focused on sustainability of soil warming on microbial activity associated with SOM decomposition. Two alternative hypotheses: 1) acclimation because of substrate exhaustion and 2) sustaining increase of microbial activity with accelerated decomposition of recalcitrant SOM pools were never proven under long term field conditions. This is especially important in the nowadays introduced no-till crop systems leading to redistribution of organic C at the soil surface, which is much susceptible to warming effects than the rest of the profile. We incubated soil samples from a four-year warming experiment with tillage (T) and no-tillage (NT) practices under three temperatures: 15, 21, and 27 °C, and related the evolved total CO2 efflux to changes of organic C pools. Warmed soils released significantly more CO2 than the control treatment (no warming) at each incubation temperature, and the largest differences were observed under 15 °C (26% increase). The difference in CO2 efflux from NT to T increase with temperature showing high vulnerability of C stored in NT to soil warming. The Q10 value reflecting the sensitivity of SOM decomposition to warming was lower for warmed than non-warmed soil indicating better acclimation of microbes or lower C availability during long term warming. The activity of three extracellular enzymes: ?-glucosidase, chitinase, sulphatase, reflecting the response of C, N and S cycles to warming, were significantly higher under warming and especially under NT compared to two other respective treatments. The CO2 released during 2 months of incubation consisted of 85% from recalcitrant SOM and the remaining 15% from microbial biomass and extractable organic C based on the decrease of respective OM pools during incubation. The dominance of CO2 from recalcitrant SOM was especially pronounced in NT. We conclude that the accelerated decomposition of recalcitrant SOM due to stimulation of microorganisms by warming is sustainable. Consequently, predictions of redistribution or even accumulation of C in the topsoil of no-till should be taken with high caution, as global warming could potentially sustain high rates of decomposition.

  18. MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012

    NASA Astrophysics Data System (ADS)

    Aleksi?, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Carreto Fidalgo, D.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; Delgado Mendez, C.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Farina, E.; Ferenc, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Godinovi?, N.; González Muñoz, A.; Gozzini, S. R.; Hadasch, D.; Hayashida, M.; Herrera, J.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K.; Noda, K.; Nowak, N.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Partini, S.; Persic, M.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Preziuso, S.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saggion, A.; Saito, T.; Saito, K.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamatescu, V.; Stamerra, A.; Steinbring, T.; Storz, J.; Strzys, M.; Sun, S.; Suri?, T.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzi?, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Uellenbeck, M.; Vogler, P.; Wagner, R. M.; Zandanel, F.; Zanin, R.; MAGIC Collaboration; Lucarelli, F.; Pittori, C.; Vercellone, S.; Verrecchia, F.; AGILE Collaboration; Buson, S.; D'Ammando, F.; Stawarz, L.; Giroletti, M.; Orienti, M.; Fermi-LAT Collaboration; Mundell, C.; Steele, I.; Zarpudin, B.; Raiteri, C. M.; Villata, M.; Sandrinelli, A.; Lähteenmäki, A.; Tammi, J.; Tornikoski, M.; Hovatta, T.; Readhead, A. C. S.; Max-Moerbeck, W.; Richards, J. L.; Jorstad, S.; Marscher, A.; Gurwell, M. A.; Larionov, V. M.; Blinov, D. A.; Konstantinova, T. S.; Kopatskaya, E. N.; Larionova, L. V.; Larionova, E. G.; Morozova, D. A.; Troitsky, I. S.; Mokrushina, A. A.; Pavlova, Yu. V.; Chen, W. P.; Lin, H. C.; Panwar, N.; Agudo, I.; Casadio, C.; Gómez, J. L.; Molina, S. N.; Kurtanidze, O. M.; Nikolashvili, M. G.; Kurtanidze, S. O.; Chigladze, R. A.; Acosta-Pulido, J. A.; Carnerero, M. I.; Manilla-Robles, A.; Ovcharov, E.; Bozhilov, V.; Metodieva, I.; Aller, M. F.; Aller, H. D.; Fuhrman, L.; Angelakis, E.; Nestoras, I.; Krichbaum, T. P.; Zensus, J. A.; Ungerechts, H.; Sievers, A.

    2014-09-01

    Aims: Amongst more than fifty blazars detected in very high energy (VHE, E> 100 GeV) ? rays, only three belong to the subclass of flat spectrum radio quasars (FSRQs). The detection of FSRQs in the VHE range is challenging, mainly because of their soft spectra in the GeV-TeV regime. MAGIC observed PKS 1510-089 (z = 0.36) starting 2012 February 3 until April 3 during a high activity state in the high energy (HE, E> 100 MeV) ?-ray band observed by AGILE and Fermi. MAGIC observations result in the detection of a source with significance of 6.0 standard deviations (?). We study the multi-frequency behaviour of the source at the epoch of MAGIC observation, collecting quasi-simultaneous data at radio and optical (GASP-WEBT and F-Gamma collaborations, REM, Steward, Perkins, Liverpool, OVRO, and VLBA telescopes), X-ray (Swift satellite), and HE ?-ray frequencies. Methods: We study the VHE ?-ray emission, together with the multi-frequency light curves, 43 GHz radio maps, and spectral energy distribution (SED) of the source. The quasi-simultaneous multi-frequency SED from the millimetre radio band to VHE ? rays is modelled with a one-zone inverse Compton model. We study two different origins of the seed photons for the inverse Compton scattering, namely the infrared torus and a slow sheath surrounding the jet around the Very Long Baseline Array (VLBA) core. Results: We find that the VHE ?-ray emission detected from PKS 1510-089 in 2012 February-April agrees with the previous VHE observations of the source from 2009 March-April. We find no statistically significant variability during the MAGIC observations on daily, weekly, or monthly time scales, while the other two known VHE FSRQs (3C 279 and PKS 1222+216) have shown daily scale to sub-hour variability. The ?-ray SED combining AGILE, Fermi and MAGIC data joins smoothly and shows no hint of a break. The multi-frequency light curves suggest a common origin for the millimetre radio and HE ?-ray emission, and the HE ?-ray flaring starts when the new component is ejected from the 43 GHz VLBA core and the studied SED models fit the data well. However, the fast HE ?-ray variability requires that within the modelled large emitting region, more compact regions must exist. We suggest that these observed signatures would be most naturally explained by a turbulent plasma flowing at a relativistic speed down the jet and crossing a standing conical shock.

  19. Domain decomposition algorithms and computational fluid dynamics

    NASA Technical Reports Server (NTRS)

    Chan, Tony F.

    1988-01-01

    Some of the new domain decomposition algorithms are applied to two model problems in computational fluid dynamics: the two-dimensional convection-diffusion problem and the incompressible driven cavity flow problem. First, a brief introduction to the various approaches of domain decomposition is given, and a survey of domain decomposition preconditioners for the operator on the interface separating the subdomains is then presented. For the convection-diffusion problem, the effect of the convection term and its discretization on the performance of some of the preconditioners is discussed. For the driven cavity problem, the effectiveness of a class of boundary probe preconditioners is examined.

  20. Decomposition of lithium magnesium aluminum hydride

    Microsoft Academic Search

    Hilde Grove; Ole Martin Løvvik; Weiming Huang; Susanne M. Opalka; Richard H. Heyn; Bjørn C. Hauback

    2011-01-01

    The quaternary aluminum hydride LiMg(AlH4)3 contains 9.7 wt% hydrogen, of which 7.2 wt% can be released in a two-step decomposition reaction via first formation of LiMgAlH6 and then the binary hydrides MgH2 and LiH. In-situ synchrotron radiation powder X–ray diffraction and thermal desorption spectroscopy measurements were performed to analyze the product distributions formed during the thermal decomposition of LiMg(AlD4)3. The first decomposition

  1. Spectroscopic Observations of SN 2012fr: A Luminous Normal Type Ia Supernova with Early High Velocity Features and Late Velocity Plateau

    E-print Network

    Childress, M J; Sim, S A; Tucker, B E; Yuan, F; Schmidt, B P; Cenko, S B; Silverman, J M; Contreras, C; Hsiao, E Y; Phillips, M; Morrell, N; Jha, S W; McCully, C; Filippenko, A V; Anderson, J P; Benetti, S; Bufano, F; de Jaeger, T; Forster, F; Gal-Yam, A; Guillou, L Le; Maguire, K; Maund, J; Mazzali, P A; Pignata, G; Smartt, S; Spyromilio, J; Sullivan, M; Taddia, F; Valenti, S; Bayliss, D D R; Bessell, M; Blanc, G A; Carson, D J; Clubb, K I; de Burgh-Day, C; Desjardins, T D; Fang, J J; Fox, O D; Gates, E L; Ho, I-T; Keller, S; Kelly, P L; Lidman, C; Loaring, N S; Mould, J R; Owers, M; Ozbilgen, S; Pei, L; Pickering, T; Pracy, M B; Rich, J A; Schaefer, B E; Scott, N; Stritzinger, M; Vogt, F P A; Zhou, G

    2013-01-01

    We present 65 optical spectra of the Type Ia supernova SN 2012fr, of which 33 were obtained before maximum light. At early times SN 2012fr shows clear evidence of a high-velocity feature (HVF) in the Si II 6355 line which can be cleanly decoupled from the lower velocity "photospheric" component. This Si II 6355 HVF fades by phase -5; subsequently, the photospheric component exhibits a very narrow velocity width and remains at a nearly constant velocity of v~12,000 km/s until at least 5 weeks after maximum brightness. The Ca II infrared (IR) triplet exhibits similar evidence for both a photospheric component at v~12,000 km/s with narrow line width and long velocity plateau, as well as a high-velocity component beginning at v~31,000 km/s two weeks before maximum. SN 2012fr resides on the border between the "shallow silicon" and "core-normal" subclasses in the Branch et al. (2009) classification scheme, and on the border between normal and "high-velocity" SNe Ia in the Wang et al. (2009a) system. Though it is a ...

  2. Urine carcinoembryonic antigen levels are more useful than serum levels for early detection of Bilharzial and non-Bilharzial urinary bladder carcinoma: Observations of 43 Egyptian cases

    PubMed Central

    Saied, Gamal M; El-Metenawy, Wafaa H; Elwan, Mohamed S; Dessouki, Nazar R

    2007-01-01

    Background Both urinary bilharziasis and urothelial neoplasia are associated with increased production of tissue carcinoembryonic antigen (CEA). Patients and methods Urine and serum CEA were determined in 43 patients with urinary bladder carcinoma including 22 post bilharzial and 21 nonbiharzial cases, in addition to 10 normal control cases. Results A significant increase was detected in both urine and serum CEA levels with bladder carcinoma compared to control cases. Urinary CEA was significantly elevated in 86% of bilharzial, versus 62% in nonbilharzial bladder carcinoma. Only 10.5% of control cases had urinary CEA elevation. The mean urinary CEA in bilharzial, was higher than that of nonbilharzial carcinoma, but the difference was not statistically significant. There was a definite relationship between urine CEA and the stage of malignancy; the higher the stage, the higher the level of urine CEA. No relationship could be detected between the stage of malignancy and serum CEA, or between the grades of malignancy and urine or serum CEA levels. Conclusion Urinary CEA is more useful than serum CEA in the early detection of urotherlial carcinoma particularly if provoked by bilharziasis. Its level is also correlated with the tumor stage. PMID:17224047

  3. Early lunar geology and geophysics

    E-print Network

    Garrick-Bethell, Ian, 1980-

    2009-01-01

    Despite a number of human and robotic missions to the Moon, there are still important unanswered questions about its early evolution, and how it came to be the object we observe today. Here we use observational, experimental, ...

  4. Comparison of different methods to determine the degree of peat decomposition in peat bogs

    NASA Astrophysics Data System (ADS)

    Biester, H.; Knorr, K.-H.; Schellekens, J.; Basler, A.; Hermanns, Y.-M.

    2014-05-01

    Peat humification or decomposition is a frequently used proxy to extract past time changes in hydrology and climate from peat bogs. During the past century several methods to determine changes in peat decomposition have been introduced. Most of these methods are operationally defined only and the chemical changes underlying the decomposition process are often poorly understood and lack validation. Owing to the chemically undefined nature of many humification analyses the comparison of results obtained by different methods is difficult. In this study we compared changes in peat decomposition proxies in cores of two peat bogs (Königsmoor, KK; Kleines Rotes Bruch, KRB) from the Harz Mountains (Germany) using C / N ratios, Fourier transform infrared spectra absorption (FTIR) intensities, Rock Eva® oxygen and hydrogen indices, ?13C and ?15N isotopic signatures and UV-absorption (UV-ABS) of NaOH peat extracts. In order to explain parallels and discrepancies between these methods, one of the cores was additionally analysed by pyrolysis gas chromatography mass spectrometry (pyrolysis-GC-MS). Pyrolysis-GC-MS data provide detailed information on a molecular level, which allows differentiation of both changes attributed to decomposition processes and changes in vegetation. Principal component analysis was used to identify and separate the effects of changes in vegetation pattern and decomposition processes because both may occur simultaneously upon changes in bog hydrology. Records of decomposition proxies show similar historical development at both sites, indicating external forcing such as climate as controlling the process. All decomposition proxies except UV-ABS and ?15N isotopes show similar patterns in their records and reflect to different extents signals of decomposition. The molecular composition of the KK core reveals that these changes are mainly attributed to decomposition processes and to a lesser extent to changes in vegetation. Changes in the molecular composition indicate that peat decomposition in the KK bog is mainly characterized by preferential decomposition of phenols and polysaccharides and relative enrichment of aliphatics during drier periods. Enrichment of lignin and other aromatics during decomposition was also observed but showed less variation than polysaccharides or aliphatics, and presumably reflects changes in vegetation associated with changes in hydrology of the bogs. Significant correlations with polysaccharide and aliphatic pyrolysis products were found for C / N ratios, FTIR-band intensities and for hydrogen index values, supporting that these decomposition indices provide reasonable information. Correlations of polysaccharide and aliphatic pyrolysis products with oxygen index values and ?13C was weaker, assumingly indicating carboxylation of the peat during drier periods and enrichment of isotopically lighter peat components during decomposition, respectively. FTIR, C / N ratio, pyrolysis-GC-MS analyses and Rock Eval hydrogen indices appear to reflect mass loss and related changes in the molecular peat composition during mineralization best. Pyrolysis-GC-MS allows disentangling the decomposition processes and vegetation changes. UV-ABS measurements of alkaline peat extracts show only weak correlation with other decomposition proxies and pyrolysis results as they mainly reflect the formation of humic acids through humification and to a lesser extent mass loss during mineralization.

  5. Influence of smoking cessation after diagnosis of early stage lung cancer on prognosis: systematic review of observational studies with meta-analysis

    Microsoft Academic Search

    A Parsons; A Daley; R Begh; P Aveyard

    2010-01-01

    Objective To systematically review the evidence that smoking cessation after diagnosis of a primary lung tumour affects prognosis.Design Systematic review with meta-analysis.Data sources CINAHL (from 1981), Embase (from 1980), Medline (from 1966), Web of Science (from 1966), CENTRAL (from 1977) to December 2008, and reference lists of included studies.Study selection Randomised controlled trials or observational longitudinal studies that measured the

  6. Thermal Decomposition of Benzyl Radical via Multiple Active Pathways

    NASA Astrophysics Data System (ADS)

    Buckingham, Grant; Robichaud, David; Ormond, Thomas; Nimlos, Mark R.; Daily, John W.; Ellison, Barney

    2014-06-01

    The thermal decomposition of benzyl radical (C6H5CH2) has been investigated using a combination infrared absorption spectroscopy in a neon matrix and 118.2 (10.487 eV) photoionization mass spectrometry. Both techniques are coupled with a heated tubular reactor to allow temperature control over the decomposition to indicate relative barrier heights of fragmentation pathways. Three possible chemical mechanisms have been considered. 1) Ring expansion to cycloheptatrienyl radical (C7H7) with subsequent breakdown to HCCH and C5H5, 2) isomerization to the substituted five-membered ring fulvenallene (C5H4=C=CH2), which is of interest to kinetic theorists and finally 3) hydrogen shift to form methyl-substituted phenyl radical, which can then form ortho-benzyne, diacetylene and other fragments. Benzyl radical is generated from two precursors, C6H5CH2CH3 and C6H5CH2Br, and both lead to the appearance of HCCH and C5H5. At slightly hotter temperatures peaks are observed at m/z 90, presumed to be C5H4=C=CH2, and 89, potentially the substituted propargyl C5H4=C=CH. Additionally, decomposition of isotopically substituted parent molecules C6H5CD2CD3 and C6D5CH2CH3 indicates C7H7 as an intermediate due to H/D ratios in fragment molecules.

  7. Roaming radical kinetics in the decomposition of acetaldehyde.

    SciTech Connect

    Harding, L. B.; Georgievskii, Y.; Klippenstein, S. J.; Chemical Sciences and Engineering Division

    2010-01-01

    A novel theoretical framework for predicting the branching between roaming and bond fission channels in molecular dissociations is described and applied to the decomposition of acetaldehyde. This reduced dimensional trajectory (RDT) approach, which is motivated by the long-range nature of the roaming, bond fission, and abstraction dynamical bottlenecks, involves the propagation of rigid-body trajectories on an analytic potential energy surface. The analytic potential is obtained from fits to large-scale multireference ab initio electronic structure calculations. The final potential includes one-dimensional corrections from higher-level electronic structure calculations and for the effect of conserved mode variations along both the addition and abstraction paths. The corrections along the abstraction path play a significant role in the predicted branching. Master equation simulations are used to transform the microcanonical branching ratios obtained from the RDT simulations to the temperature- and pressure-dependent branching ratios observed in thermal decomposition experiments. For completeness, a transition-state theory treatment of the contributions of the tight transition states for the molecular channels is included in the theoretical analyses. The theoretically predicted branching between molecules and radicals in the thermal decomposition of acetaldehyde is in reasonable agreement with the corresponding shock tube measurement described in the companion paper. The prediction for the ratio of the tight to roaming contributions to the molecular channel also agrees well with results extracted from recent experimental and experimental/theoretical photodissociation studies.

  8. The Arm Prime Factors Decomposition Arm Boris Nima

    E-print Network

    Paris-Sud XI, Université de

    The Arm Prime Factors Decomposition Arm Boris Nima arm.boris@gmail.com Abstract We introduce the Arm prime factors decomposition which is the equivalent of the Taylor formula for decomposition-00810545,version1-10Apr2013 #12;Introduction The Arm theory [1] gives the decomposition of functions

  9. THE SCHMIDT-KENNICUTT LAW OF MATCHED-AGE STAR-FORMING REGIONS; Pa{alpha} OBSERVATIONS OF THE EARLY-PHASE INTERACTING GALAXY TAFFY I

    SciTech Connect

    Komugi, S. [Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago 763-0355 (Chile); Tateuchi, K.; Motohara, K.; Kato, N.; Konishi, M.; Koshida, S.; Morokuma, T.; Takahashi, H.; Tanabe, T.; Yoshii, Y. [Institute of Astronomy, University of Tokyo, Osawa 2-21-1, Mitaka, Tokyo 181-0015 (Japan); Takagi, T. [Institute of Space and Astronautical Science, JAXA, 3-31-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Iono, D.; Kaneko, H.; Ueda, J. [Nobeyama Radio Observatory, National Astronomical Observatory, 462-2 Nobeyama, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Saitoh, T. R., E-mail: skomugi@alma.cl [Interactive Research Center of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro 152-0033 (Japan)

    2012-10-01

    In order to test a recent hypothesis that the dispersion in the Schmidt-Kennicutt law arises from variations in the evolutionary stage of star-forming molecular clouds, we compared molecular gas and recent star formation in an early-phase merger galaxy pair, Taffy I (UGC 12915/UGC 12914, VV 254) which went through a direct collision 20 Myr ago and whose star-forming regions are expected to have similar ages. Narrowband Pa{alpha} image is obtained using the ANIR near-infrared camera on the mini-TAO 1 m telescope. The image enables us to derive accurate star formation rates within the galaxy directly. The total star formation rate, 22.2 M{sub Sun} yr{sup -1}, was found to be much higher than previous estimates. Ages of individual star-forming blobs estimated from equivalent widths indicate that most star-forming regions are {approx}7 Myr old, except for a giant H II region at the bridge which is much younger. Comparison between star formation rates and molecular gas masses for the regions with the same age exhibits a surprisingly tight correlation, a slope of unity, and star formation efficiencies comparable to those of starburst galaxies. These results suggest that Taffy I has just evolved into a starburst system after the collision, and the star-forming sites are at a similar stage in their evolution from natal molecular clouds except for the bridge region. The tight Schmidt-Kennicutt law supports the scenario that dispersion in the star formation law is in large part due to differences in evolutionary stage of star-forming regions.

  10. The second-generation z (redshift) and early universe spectrometer. I. First-light observation of a highly lensed local-ulirg analog at high-z

    SciTech Connect

    Ferkinhoff, Carl; Brisbin, Drew; Parshley, Stephen; Nikola, Thomas; Stacey, Gordon J.; Schoenwald, Justin; Riechers, Dominik [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Higdon, James L.; Higdon, Sarah J. U. [Department of Physics, Georgia Southern University, Statesboro, GA 30460 (United States); Verma, Aprajita [Department of Physics, University of Oxford, Oxford, OX1 3RH (United Kingdom); Hailey-Dunsheath, Steven [California Institute of Technology, Pasadena, CA 91125 (United States); Menten, Karl M.; Güsten, Rolf; Weiß, Axel [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Irwin, Kent; Cho, Hsiao M. [NIST Boulder, Boulder, CO 80305 (United States); Niemack, Michael [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Halpern, Mark; Amiri, Mandana [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Hasselfield, Matthew, E-mail: carl.ferkinhoff@cornell.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); and others

    2014-01-10

    We recently commissioned our new spectrometer, the second-generation z(Redshift) and Early Universe Spectrometer (ZEUS-2) on the Atacama Pathfinder Experiment telescope. ZEUS-2 is a submillimeter grating spectrometer optimized for detecting the faint and broad lines from distant galaxies that are redshifted into the telluric windows from 200 to 850 ?m. It uses a focal plane array of transition-edge sensed bolometers, the first use of these arrays for astrophysical spectroscopy. ZEUS-2 promises to be an important tool for studying galaxies in the years to come because of its synergy with Atacama Large Millimeter Array and its capabilities in the short submillimeter windows that are unique in the post-Herschel era. Here, we report on our first detection of the [C II] 158 ?m line with ZEUS-2. We detect the line at z ? 1.8 from H-ATLAS J091043.1–000322 with a line flux of (6.44 ± 0.42) × 10{sup –18} W m{sup –2}. Combined with its far-IR luminosity and a new Herschel-PACS detection of the [O I] 63 ?m line, we model the line emission as coming from a photo-dissociation region with far-ultraviolet radiation field, G ? 2 × 10{sup 4} G {sub 0}, gas density, n ? 1 × 10{sup 3} cm{sup –3} and size between ?0.4 and 1 kpc. On the basis of this model, we conclude that H-ATLAS J091043.1–000322 is a high-redshift analog of a local ultra-luminous IR galaxy; i.e., it is likely the site of a compact starburst caused by a major merger. Further identification of these merging systems is important for constraining galaxy formation and evolution models.

  11. Observational Studies and a Statistical Early Warning of Surface Ozone Pollution in Tangshan, the Largest Heavy Industry City of North China

    PubMed Central

    Li, Pei; Xin, Jinyuan; Bai, Xiaoping; Wang, Yuesi; Wang, Shigong; Liu, Shixi; Feng, Xiaoxin

    2013-01-01

    Continuous measurements of surface ozone (O3) and nitrogen oxides (NOX) at an urban site (39°37?N, 118°09?E) in Tangshan, the largest heavy industry city of North China during summertime from 2008 to 2011 are presented. The pollution of O3 was serious in the city. The daily maximum 1 h means (O3_1-hr max) reached 157 ± 55, 161 ± 54, 120 ± 50, and 178 ± 75 ?g/m3 corresponding to an excess over the standard rates of 21%, 27%, 10%, and 40% in 2008–2011, respectively. The total oxidant level (OX = O3 + NO2) was high, with seasonal average concentrations up to 100 ?g/m3 in summer. The level of OX at a given location was made up of NOX-independent and NOX-dependent contributions. The independent part can be considered as a regional contribution and was about 100 ?g/m3 in Tangshan. Statistical early warning analysis revealed that the O3 levels would exceed the standard rate by 50% on the day following a day when the daily average ozone concentration (O3_mean) exceeded 87 ?g/m3 and the daily maximum temperature (T_max) exceeded 29 °C. The exceed-standard rate would reach 80% when O3_mean and T_max exceeded 113 ?g/m3 and 31 °C. Similarly, the exceed-standard rate would reach 100% when O3_mean and T_max exceeded 127 ?g/m3 and 33 °C, respectively. PMID:23485953

  12. A preliminary fMRI study of a novel self-paced written fluency task: observation of left-hemispheric activation, and increased frontal activation in late vs. early task phases

    PubMed Central

    Golestanirad, Laleh; Das, Sunit; Schweizer, Tom A.; Graham, Simon J.

    2015-01-01

    Neuropsychological tests of verbal fluency are very widely used to characterize impaired cognitive function. For clinical neuroscience studies and potential medical applications, measuring the brain activity that underlies such tests with functional magnetic resonance imaging (fMRI) is of significant interest—but a challenging proposition because overt speech can cause signal artifacts, which tend to worsen as the duration of speech tasks becomes longer. In a novel approach, we present the group brain activity of 12 subjects who performed a self-paced written version of phonemic fluency using fMRI-compatible tablet technology that recorded responses and provided task-related feedback on a projection screen display, over long-duration task blocks (60 s). As predicted, we observed robust activation in the left anterior inferior and medial frontal gyri, consistent with previously reported results of verbal fluency tasks which established the role of these areas in strategic word retrieval. In addition, the number of words produced in the late phase (last 30 s) of written phonemic fluency was significantly less (p < 0.05) than the number produced in the early phase (first 30 s). Activation during the late phase vs. the early phase was also assessed from the first 20 s and last 20 s of task performance, which eliminated the possibility that the sluggish hemodynamic response from the early phase would affect the activation estimates of the late phase. The last 20 s produced greater activation maps covering extended areas in bilateral precuneus, cuneus, middle temporal gyrus, insula, middle frontal gyrus and cingulate gyrus. Among these areas, greater activation was observed in the bilateral middle frontal gyrus (Brodmann area BA 9) and cingulate gyrus (BA 24, 32) likely as part of the initiation, maintenance, and shifting of attentional resources. Consistent with previous pertinent fMRI literature involving overt and covert verbal responses, these findings highlight the promise and practicality of fMRI of written phonemic fluency. PMID:25805984

  13. Understanding litter decomposition in semiarid ecosystems: linking leaf traits, UV exposure and rainfall variability.

    PubMed

    Gaxiola, Aurora; Armesto, Juan J

    2015-01-01

    Differences in litter quality, microbial activity or abiotic conditions cannot fully account for the variability in decomposition rates observed in semiarid ecosystems. Here we tested the role of variation in litter quality, water supply, and UV radiation as drivers of litter decomposition in arid lands. And show that carry-over effects of litter photodegradation during dry periods can regulate decomposition during subsequent wet periods. We present data from a two-phase experiment, where we first exposed litter from a drought-deciduous and an evergreen shrub to natural UV levels during five, rainless summer months and, subsequently, in the laboratory, we assessed the carry-over effects of photodegradation on biomass loss under different irrigation treatments representing the observed range of local rainfall variation among years (15-240 mm). Photodegradation of litter in the field produced average carbon losses of 12%, but deciduous Proustia pungens lost >25%, while evergreen Porlieria chilensis less than 5%. Natural exposure to UV significantly reduced carbon-to-nitrogen and lignin:N ratios in Proustia litter but not in Porlieria. During the subsequent wet phase, remaining litter biomass was lower in Proustia than in Porlieria. Indeed UV exposure increased litter decomposition of Proustia under low and medium rainfall treatments, whereas no carry-over effects were detected under high rainfall treatment. Consequently, for deciduous Proustia carry-over effects of UV exposure were negligible under high irrigation. Litter decomposition of the evergreen Porlieria depended solely on levels of rainfall that promote microbial decomposers. Our two-phase experiment revealed that both the carry-over effects of photodegradation and litter quality, modulated by inter-annual variability in rainfall, can explain the marked differences in decomposition rates and the frequent decoupling between rainfall and litter decomposition observed in semiarid ecosystems. PMID:25852705

  14. Decomposition of fluorophosphoryl diazide: a joint experimental and theoretical study.

    PubMed

    Li, Dingqing; Li, Hongmin; Zhu, Bifeng; Zeng, Xiaoqing; Willner, Helge; Beckers, Helmut; Neuhaus, Patrik; Grote, Dirk; Sander, Wolfram

    2015-03-01

    The photolytic and thermal decomposition of fluorophosphoryl diazide, FP(O)(N3)2, was studied using matrix isolation spectroscopy. Upon ArF laser photolysis (? = 193 nm), FPO and a new geminal azido nitrene FP(O)(N3)N were identified using matrix IR spectroscopy. The nitrene shows a triplet ground state with the zero-field parameters |D/hc| = 1.566 cm(-1) and |E/hc| = 0.005 cm(-1). Further decomposition of the nitrene into FPO was observed under an irradiation of ? > 335 nm. In contrast, no nitrene but only FPO was identified after flash vacuum pyrolysis of the diazide. To reveal the decomposition mechanism, quantum chemical calculations on the potential energy surface (PES) of the diazide using DFT methods were performed. On the singlet PES four conformers of the nitrene were predicted. The two conformers (syn and anti) showing intramolecular Nnitrene···N?,azide interactions are much lower in energy (ca. 40 kJ mol(-1), B3LYP/6-311+G(3df)) than the other two exhibiting Nnitrene···O interactions. syn/anti refers to the relative orientation of the P[double bond, length as m-dash]O bond and the N3 group. The interconversion of these species and the decomposition into FPO via a novel three-membered ring diazo intermediate cyclo-FP(O)N2 were computationally explored. The calculated low dissociation barrier of 45 kJ mol(-1) (B3LYP/6-311+G(3df)) of this cyclic intermediate rationalizes why it could not be detected in our experiments. PMID:25656843

  15. Temperature sensitivity of black carbon decomposition and oxidation.

    PubMed

    Nguyen, Binh Thanh; Lehmann, Johannes; Hockaday, William C; Joseph, Stephen; Masiello, Caroline A

    2010-05-01

    Global warming accelerates decomposition of soil organic carbon (SOC) pools with varying rates and temperature sensitivities. Black carbon (BC) materials are among the slowest decomposing components of the SOC pool. Although BC is a large component of SOC in many systems, the influence of temperature on decomposition of BC bearing different chemical and physical structures remains poorly understood. Four BC materials, produced by carbonizing corn residue and oak wood at 350 and 600 degrees C (corn-350-BC, corn-600-BC, oak-350-BC, and oak-600-BC), were mixed with pure sand and incubated at 4, 10, 20, 30, 45, and 60 degrees C for 1 year. Corn-BC was more porous than oak-BC as determined by scanning electron microscopy (SEM). Increasing the charring temperature from 350 to 600 degrees C led to greater aromaticity with 5-15% more C in aromatic rings and a 39-57% increase in both nonprotonated aromatic C and aromatic bridgehead C quantified by nuclear magnetic resonance (NMR) spectroscopy and a greater degree of order and development of C layers as observed by transmission electron microscopy (TEM). With a temperature increase from 4 to 60 degrees C, C loss of corn-350-BC increased from 10 to 20%, corn-600-BC, from 4 to 20%, oak-350-BC, from 2.3 to 15%, and oak-600-BC from 1.5 to 14% of initial C content, respectively. Temperature sensitivity (Q(10)) decreased with increasing incubation temperature and was highest in oak-600-BC, followed by oak-350-BC, corn-600-BC, and corn-350-BC, indicating that decomposition of more stable BC was more sensitive to increased temperature than less stable materials. Carbon loss and potential cation exchange capacity (CECp) significantly (p < 0.05) correlated with O/C ratios and change in O/C ratios, suggesting that oxidative processes were the most important mechanism controlling BC decomposition in this study. PMID:20384335

  16. Approximate convex decomposition and its applications 

    E-print Network

    Lien, Jyh-Ming

    2009-05-15

    similar benefits as convex components, while the resulting decomposition is both significantly smaller (typically by orders of magnitude) and can be computed more efficently. Indeed, for many applications, an ACD can represent the important structural...

  17. Heuristic Decomposition Algorithms for Generalized Shop Scheduling

    E-print Network

    Magdeburg, Universität

    Heuristic Decomposition Algorithms for Generalized Shop Scheduling Problems Karin Kr¨uger Otto generalized shop scheduling problems, where arbitrary precedence constraints among the operations are given (general shop), sequence--dependent changeover times between the processing of operations are taken

  18. Temperature programmed decomposition of thorium oxalate hexahydrate

    NASA Astrophysics Data System (ADS)

    Dash, S.; Krishnan, R.; Kamruddin, M.; Tyagi, A. K.; Raj, Baldev

    2001-06-01

    Temperature programmed decomposition (TPD) of thorium oxalate hexahydrate (TOH) was studied by evolved gas analysis-mass spectrometry (EGA-MS), thermogravimetric analysis (TGA) and powder X-ray diffraction (XRD). The microcrystalline solid exhibited sequential dehydration. The anhydrous compound yielded amorphous phase Th(CO 3) 2 upon CO release arising out of the bond cleavage. The Th(CO 3) 2 phase transformed to nano-crystalline thoria upon decomposition through an oxycarbonate intermediate. The mechanism underlying various conversion stages exhibited control by random nucleation, diffusion and phase boundary interface motion. From the fractional extent of decomposition data, Arrhenius factors like activation energy and pre-exponential factors were evaluated. Based on these studies, a chemical pathway is proposed for the entire decomposition process.

  19. Polynomial decomposition algorithms in signal processing

    E-print Network

    Su, Guolong, S.M. Massachusetts Institute of Technology

    2013-01-01

    Polynomial decomposition has attracted considerable attention in computational mathematics. In general, the field identifies polynomials f(x) and g(x) such that their composition f(g(x)) equals or approximates a given ...

  20. Short Communication Differential decomposition of arbuscular mycorrhizal

    E-print Network

    Rilli, Matthias C.

    ; received in revised form 30 October 2002; accepted 4 November 2002 Abstract Arbuscular mycorrhizal fungi; Soil carbon; Arbuscular mycorrhiza Arbuscular mycorrhizal fungi (AMF) are ubiquitous endosymbiontsShort Communication Differential decomposition of arbuscular mycorrhizal fungal hyphae and glomalin

  1. Analysis of unknown words through morphological decomposition

    E-print Network

    van de Plassche, J; Black, Alan W

    1991-01-01

    This paper describes a method of analysing words through morphological decomposition when the lexicon is incomplete. The method is used within a text-to-speech system to help generate pronunciations of unknown words. The ...

  2. Finite element decomposition of the human neocortex 

    E-print Network

    Chow, Seeling

    1998-01-01

    boundary-conforming local coordinate systems for the systematic study and visualization of cortical neuron populations. The decomposition method is implemented with a newly developed set of object-oriented software tools....

  3. Management intensity alters decomposition via biological pathways

    E-print Network

    Cleveland, Cory

    , extracellular enzyme activity, microarthropod communities, and bacterial versus fungal relative abundance and the importance of litter chemistry in regulating soil organic matter storage, our objectives were to determine community composition and activity. We measured decomposition rates, changes in litter chemistry

  4. Critical analysis of nitramine decomposition data: Activation energies and frequency factors for HMX and RDX decomposition

    NASA Technical Reports Server (NTRS)

    Schroeder, M. A.

    1980-01-01

    A summary of a literature review on thermal decomposition of HMX and RDX is presented. The decomposition apparently fits first order kinetics. Recommended values for Arrhenius parameters for HMX and RDX decomposition in the gaseous and liquid phases and for decomposition of RDX in solution in TNT are given. The apparent importance of autocatalysis is pointed out, as are some possible complications that may be encountered in interpreting extending or extrapolating kinetic data for these compounds from measurements carried out below their melting points to the higher temperatures and pressure characteristic of combustion.

  5. Long-term decomposition of grass roots as affected by elevated atmospheric carbon dioxide

    SciTech Connect

    Ginkel, J.H. van; Gorissen, A. [Institute for Agrobiology and Soil Fertility, Wageningen (Netherlands); Veen, J.A. van [Leiden Univ. (Netherlands)

    1996-09-01

    Carbon input the soil and decomposition processes under elevated CO{sub 2} are highly relevant for C sequestering in the soil. Plant growth and decomposition of root material under ambient and elevated atmospheric CO{sub 2} concentrations were monitored in wind tunnels. Grass roots (Lolium perenne L.) were homogeneously {sup 14}C-labeled at 350 and 700 {mu}L L{sup -1} CO{sub 2} and at two N levels to obtain roots of different qualities. This root material was mixed with fresh loamy sand and transferred to four wind tunnels to observe its decomposition in bare soil and as affected by plant growth (L. perenne) at ambient CO{sub 2} and elevated CO{sub 2} for two growing seasons. After the second growing season, elevated CO{sub 2} had stimulated shoot and root growth by 13 and 92%, respectively. The CO{sub 2} and N concentrations at which the grass roots had been grown affected the decomposition rate. After the first growing season, the overall decomposition of 700 roots was 19% lower than that of 350 roots. The {sup 14}C-labeled microbial biomass in the soil with 700 roots was higher (44%) compared with 350 roots. After the second growing season, the decomposition of 700 low N roots was 14% lower than that of 350 low N roots, whereas the decomposition of the high N roots was unaffected. The {sup 14}C-labeled microbial biomass in the soil with 700 roots was still higher (30%) than with 350 roots. The combination of higher root yields at elevated CO{sub 2} combined with a decrease in root decomposition will lead to a longer residence time of C in the soil and probably to a higher C storage. 36 refs., 1 fig., 5 tabs.

  6. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2005-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  7. Moisture drives surface decomposition in thawing tundra

    NASA Astrophysics Data System (ADS)

    Hicks Pries, Caitlin E.; Schuur, E. A. G.; Vogel, Jason G.; Natali, Susan M.

    2013-07-01

    Permafrost thaw can affect decomposition rates by changing environmental conditions and litter quality. As permafrost thaws, soils warm and thermokarst (ground subsidence) features form, causing some areas to become wetter while other areas become drier. We used a common substrate to measure how permafrost thaw affects decomposition rates in the surface soil in a natural permafrost thaw gradient and a warming experiment in Healy, Alaska. Permafrost thaw also changes plant community composition. We decomposed 12 plant litters in a common garden to test how changing plant litter inputs would affect decomposition. We combined species' tissue-specific decomposition rates with species and tissue-level estimates of aboveground net primary productivity to calculate community-weighted decomposition constants at both the thaw gradient and warming experiment. Moisture, specifically growing season precipitation and water table depth, was the most significant driver of decomposition. At the gradient, an increase in growing season precipitation from 200 to 300 mm increased mass loss of the common substrate by 100%. At the warming experiment, a decrease in the depth to the water table from 30 to 15 cm increased mass loss by 100%. At the gradient, community-weighted decomposition was 21% faster in extensive than in minimal thaw, but was similar when moss production was included. Overall, the effect of climate change and permafrost thaw on surface soil decomposition are driven more by precipitation and soil environment than by changes to plant communities. Increasing soil moisture is thereby another mechanism by which permafrost thaw can become a positive feedback to climate change.

  8. Catalysis of methane decomposition over elemental carbon

    Microsoft Academic Search

    N. Muradov

    2001-01-01

    Catalytic decomposition of methane is an attractive method for CO\\/CO2-free production of hydrogen, particularly, for fuel cell applications. Over 30 different samples of elemental carbon, including a variety of activated carbons (ACs), carbon blacks (CBs), nanostructured carbons (including, carbon nanotubes and fullerenes C60\\/70), graphites, glassy carbon and synthetic diamond powders, were screened for the catalytic activity in methane decomposition reaction.

  9. Tiling Models for Spatial Decomposition in AMTRAN

    SciTech Connect

    Compton, J C; Clouse, C J

    2005-05-27

    Effective spatial domain decomposition for discrete ordinate (S{sub n}) neutron transport calculations has been critical for exploiting massively parallel architectures typified by the ASCI White computer at Lawrence Livermore National Laboratory. A combination of geometrical and computational constraints has posed a unique challenge as problems have been scaled up to several thousand processors. Carefully scripted decomposition and corresponding execution algorithms have been developed to handle a range of geometrical and hardware configurations.

  10. Joint Eigenvalue Decomposition Using Polar Matrix Factorization

    Microsoft Academic Search

    Xavier Luciani; Laurent Albera

    2010-01-01

    \\u000a In this paper we propose a new algorithm for the joint eigenvalue decomposition of a set of real non-defective matrices. Our\\u000a approach resorts to a Jacobi-like procedure based on polar matrix decomposition. We introduce a new criterion in this context\\u000a for the optimization of the hyperbolic matrices, giving birth to an original algorithm called JDTM. This algorithm is described\\u000a in

  11. Domain decomposition for the SPN solver MINOS

    SciTech Connect

    Jamelot, Erell; Baudron, Anne-Marie; Lautard, Jean-Jacques [CEA Saclay, DEN DANS DM2S SERMA LLPR, Commissariat Energie Atom et Energies Alternat, F-91191 Gif Sur Yvette, (France)

    2012-07-01

    In this article we present a domain decomposition method for the mixed SPN equations, discretized with Raviart-Thomas-Nedelec finite elements. This domain decomposition is based on the iterative Schwarz algorithm with Robin interface conditions to handle communications. After having described this method, we give details on how to optimize the convergence. Finally, we give some numerical results computed in a realistic 3D domain. The computations are done with the MINOS solver of the APOLLO3 (R) code. (authors)

  12. Photometric Decomposition of Barred Galaxies

    E-print Network

    A. S. Reese; T. B. Williams; J. A. Sellwood; Eric I. Barnes; Brian A. Powell

    2007-02-27

    We present a non-parametric method for decomposition of the light of disk galaxies into disk, bulge and bar components. We have developed and tested the method on a sample of 68 disk galaxies for which we have acquired I-band photometry. The separation of disk and bar light relies on the single assumption that the bar is a straight feature with a different ellipticity and position angle from that of the projected disk. We here present the basic method, but recognise that it can be significantly refined. We identify bars in only 47% of the more nearly face-on galaxies in our sample. The fraction of light in the bar has a broad range from 1.3% to 40% of the total galaxy light. If low-luminosity galaxies have more dominant halos, and if halos contribute to bar stability, the luminosity functions of barred and unbarred galaxies should differ markedly; while our sample is small, we find only a slight difference of low significance.

  13. Predictions and observations of HF radio propagation in the northerly ionosphere: The effect of the solar flares and a weak CME in early January 2014.

    NASA Astrophysics Data System (ADS)

    Hallam, Jonathan; Stocker, Alan J.; Warrington, Mike; Siddle, Dave; Zaalov, Nikolay; Honary, Farideh; Rogers, Neil; Boteler, David; Danskin, Donald

    2014-05-01

    We have previously reported on a significant new multi-national project to provide improved predictions and forecasts of HF radio propagation for commercial aircraft operating on trans-polar routes. In these regions, there are limited or no VHF air-traffic control facilities and geostationary satellites are below the horizon. Therefore HF radio remains important in maintaining communications with the aircraft at all times. Space weather disturbances can have a range of effects on the ionosphere and hence HF radio propagation - particularly in the polar cap. While severe space weather effects can lead to a total loss of communications (i.e. radio blackout), less intense events can still cause significant disruption. In this paper we will present the effect of a series of M and X class solar flares and a relatively weak CME on HF radio performance from 6 to 13 January 2014. This is an interesting interval from the point of view of HF radio propagation because while the solar effects on the ionosphere are significant, except for an interval of approximately 12 hours duration, they are not so intense as to produce a complete radio blackout on all paths. Observations of the signal-to-noise ratio, direction of arrival, and time of flight of HF radio signals on six paths (one entirely within the polar cap, three trans-auroral, and two sub-auroral) will be presented together with riometer measurements of the ionospheric absorption. Global maps of D-region absorption (D-region absorption prediction, DRAP) inferred from satellite measurements of the solar wind parameters will be compared with the HF and riometer observations. In addition, a ray-tracing model using a realistic background ionosphere and including localised features found in the ionospheric polar cap (e.g. polar patches and arcs) will be used to model the expected and observed HF radio propagation characteristics.

  14. Individual migration of mesentodermal cells in the early embryo of the squid Loligo vulgaris: in vivo recordings combined with observations with TEM and SEM.

    PubMed

    Segmüller, M; Marthy, H J

    1989-06-01

    In the translucent preorganogenetic embryo of the squid Loligo vulgaris a population of single cells between the ectodermal layer and the yolk syncytium can be studied continuously in vivo during migration to the vegetal hemisphere of the egg. The results from 2 different preparations are reported: 1. An intact embryo served to view locomotive cell behavior through the translucent ectoderm with undisturbed cell-substrate interactions. 2. In an embryo a patch of ectoderm was microsurgically removed thereby exposing migrating cells to direct observation and experimental manipulation. In vivo time lapse microcinematographic recordings for 22 h (in 1.) and 10 h (in 2.) revealed the following: cell migration is neither directional nor dependent on the presence of the ectodermal layer (in 2.). Although the migrating cells primarily use the syncytial surface as a substrate for locomotion, under natural conditions they also adhere to the basal ectodermal surface as revealed by TEM and SEM. Migration rates were 18.3 +/- 12.6 mu/h in 1. Locally directed cell migration was observed in a group of cells in 1. which were involved in a process of aggregation, the latter being probably related to precocious formation of organ primordia. A preliminary note has appeared previously (Segmüller and Marthy, 1984). PMID:2641349

  15. Far-infrared emission from the bulges of early-type spirals: KAO observations of NGC 4736 (M94) and NGC 3627 (M66)

    NASA Technical Reports Server (NTRS)

    Smith, Beverly J.; Harvey, P. M.; Colome, C.; Zhang, C. Y.; Difrancesco, J.; Pogge, R. W.

    1994-01-01

    We present new high spatial resolution Kuiper Airborne Observatory (KAO) 50 and 100 micrometers measurements of the ringed Sab galaxy NGC 4736 and the Sb galaxy NGC 3627. We detect strong far-infrared emission (approximately 10(exp 9) solar luminosity) from the bulge areas of these galaxies, regions where there is little observed star formation. This far-infrared radiation is extended over the bulge with spatial distributions similar to that of the old stellar population. The ratio of far-infrared to H-alpha luminosity for these central sources is significantly larger than for the star-forming regions in these galaxies. This ratio is higher than can be accounted for by dust heating due to a population of young stars with a mass distribution similar to the Salpeter initial mass function assuming current estimates of extinction, unless the upper mass limit is unusually low (approximately B1 stars). On the other hand, the bolometric luminosity of the observed bulge stars is sufficient to account for the far-infrared radiation. Thus, older stars are likely to be important in heating dust in these bulges. The dust in the centers of these galaxies is quite warm, approximately 40 K (lambda(exp -1) emissivity), however, the interstellar radiation fields derived from the optical luminosities are consistent with these temperatures without invoking hidden central star formation or a dusty active galactic nucleus.

  16. Do Transposed-Letter Similarity Effects Occur at a Morpheme Level? Evidence for Morpho-Orthographic Decomposition

    ERIC Educational Resources Information Center

    Dunabeitia, Jon Andoni; Peream, Manuel; Carreiras, Manuel

    2007-01-01

    When does morphological decomposition occur in visual word recognition? An increasing body of evidence suggests the presence of early morphological processing. The present work investigates this issue via an orthographic similarity manipulation. Three masked priming lexical decision experiments were conducted to examine the transposed-letter…

  17. An observational study of bimatoprost 0.01% in patients on prior intraocular pressure-lowering therapy: the Canadian Lumigan® RC Early Analysis Review (CLEAR) trial

    PubMed Central

    Crichton, Andrew C; Nixon, Donald R; Simonyi, Susan; Bhogal, Meetu; Sigouin, Christopher S; Discepola, Marino J; Hutnik, Cindy ML; Baptiste, Darryl C; Yan, David B

    2014-01-01

    Purpose To evaluate the ocular hyperemia and intraocular pressure (IOP)-lowering efficacy of bimatoprost 0.01% in subjects with elevated IOP due to primary open-angle glaucoma (POAG) or ocular hypertension (OHT) in a real-world clinical setting. Subjects and methods This open-label, 12-week, observational study was conducted at 67 centers in Canada. Subjects with elevated IOP due to POAG or OHT instilled bimatoprost 0.01% as monotherapy once daily. Ocular hyperemia was graded by the investigator at baseline, week 6, and week 12 using a standardized photographic 5-point grading scale. Change in IOP from baseline was also evaluated at these time points. This analysis includes the subgroup of 268 subjects who had been previously treated with latanoprost 0.005%, bimatoprost 0.03%, travoprost 0.004%, and travoprost 0.004% with SofZia™ or nonselective beta-adrenergic receptor blockers prior to the study. Results After 12 weeks of treatment with 0.01% bimatoprost, ocular hyperemia was graded as none-to-mild hyperemia (grades 0, +0.5, or +1) for 94.1% of subjects and as moderate-to-severe hyperemia (grades +2 or +3) for 5.9%. No statistically significant shifts in ocular hyperemia ratings were observed at week 12 for any of the prior IOP-lowering therapies except bimatoprost 0.03%, in which 20.8% of subjects experienced an improvement. The mean percentage change from baseline IOP at week 12 following the switch to bimatoprost 0.01% monotherapy ranged from ?2.3%±17.3% to ?26.3%±12.4%. Furthermore, the decreased mean percentage change from baseline IOP was statistically significant across all prior IOP-lowering medications, except for bimatoprost 0.03% at the 6- and 12-week visits and travoprost 0.004% at the 6-week visit. Conclusion This observational study demonstrates that bimatoprost 0.01% was well tolerated among POAG and OHT subjects who switched from prior IOP-lowering medication. Furthermore, a switch in ocular hypertensive treatment to bimatoprost 0.01% was associated with an additional 10%–15% reduction in IOP. PMID:24920879

  18. Irreducible decompositions in metric-affine gravity models

    E-print Network

    Yu. N. Obukhov; E. J. Vlachynsky; W. Esser; F. W. Hehl

    1997-05-14

    The irreducible decomposition technique is applied to the study of classical models of metric-affine gravity (MAG). The dynamics of the gravitational field is described by a 12-parameter Lagrangian encompassing a Hilbert-Einstein term, torsion and nonmetricity square terms, and one quadratic curvature piece that is built up from Weyl's segmental curvature. Matter is represented by a hyperfluid, a continuous medium the elements of which possess classical momentum and hypermomentum. With the help of irreducible decompositions, we are able to express torsion and traceless nonmetricity explicitly in terms of the spin and the shear current of the hyperfluid. Thereby the field equations reduce to an effective Einstein theory describing a metric coupled to the Weyl 1-form (a Proca-type vector field) and to a spin fluid. We demonstrate that a triplet of torsion and nonmetricity 1-forms describes the general and unique vacuum solution of the field equations of MAG. Finally, we study homogeneous cosmologies with an hyperfluid. We find that the hypermomentum affects significantly the cosmological evolution at very early stages. However, unlike spin, shear does not prevent the formation of a cosmological singularity.

  19. Chandra Observations of the Pleiades Open Cluster: X-ray Emission from Late-B to Early-F Type Binaries

    E-print Network

    Kathryne J. Daniel; Jeffrey L. Linsky; Marc Gagne

    2002-06-13

    We present the analysis of a 38.4 ks and a 23.6 ks observation of the core of the Pleiades open cluster. The Advanced CCD Imaging Spectrometer on board the Chandra X-ray Observatory detected 99 X-ray sources in a 17'X17' region, including 18 of 23 Pleiades members. Five candidate Pleiades members have also been detected, confirming their cluster membership. Fifty-seven sources have no optical or near-infrared counterparts to limiting magnitudes V=22.5 and J=14.5. The unidentified X-ray sources are probably background AGN and not stars. The Chandra field of view contains seven intermediate mass cluster members. Five of these, HII 980 (B6 + G), HII 956 (A7 + F6), HII 1284 (A9 + K), HII 1338 (F3 + F6), and HII 1122 (F4 + K), are detected in this study. All but HII 1284 have high X-ray luminosity and soft X-ray spectra. HII 1284 has X-ray properties comparable to non-flaring K-type stars. Since all five stars are visual or spectroscopic binaries with X-ray properties similar to F-G stars, the late-type binary companions are probably producing the observed coronal X-ray emission. Strengthening this conclusion is the nondetection by Chandra of two A stars, HII 1362 (A7, no known companion) and HII 1375 (A0 + A SB) with X-ray luminosity upper limits 27-54 times smaller than HII 980 and HII 956, the B6-A7 stars with cooler companions. Despite the low number statistics, the Chandra data appear to confirm the expectation that late-B and A stars are not strong intrinsic X-ray sources. The ACIS spectra and hardness ratios suggest a gradual increase in coronal temperature with decreasing mass from F4 to K. M stars appear to have somewhat cooler coronae than active K stars.

  20. Aridity and decomposition processes in complex landscapes

    NASA Astrophysics Data System (ADS)

    Ossola, Alessandro; Nyman, Petter

    2015-04-01

    Decomposition of organic matter is a key biogeochemical process contributing to nutrient cycles, carbon fluxes and soil development. The activity of decomposers depends on microclimate, with temperature and rainfall being major drivers. In complex terrain the fine-scale variation in microclimate (and hence water availability) as a result of slope orientation is caused by differences in incoming radiation and surface temperature. Aridity, measured as the long-term balance between net radiation and rainfall, is a metric that can be used to represent variations in water availability within the landscape. Since aridity metrics can be obtained at fine spatial scales, they could theoretically be used to investigate how decomposition processes vary across complex landscapes. In this study, four research sites were selected in tall open sclerophyll forest along a aridity gradient (Budyko dryness index ranging from 1.56 -2.22) where microclimate, litter moisture and soil moisture were monitored continuously for one year. Litter bags were packed to estimate decomposition rates (k) using leaves of a tree species not present in the study area (Eucalyptus globulus) in order to avoid home-field advantage effects. Litter mass loss was measured to assess the activity of macro-decomposers (6mm litter bag mesh size), meso-decomposers (1 mm mesh), microbes above-ground (0.2 mm mesh) and microbes below-ground (2 cm depth, 0.2 mm mesh). Four replicates for each set of bags were installed at each site and bags were collected at 1, 2, 4, 7 and 12 months since installation. We first tested whether differences in microclimate due to slope orientation have significant effects on decomposition processes. Then the dryness index was related to decomposition rates to evaluate if small-scale variation in decomposition can be predicted using readily available information on rainfall and radiation. Decomposition rates (k), calculated fitting single pool negative exponential models, generally decreased with increasing aridity with k going from 0.0025 day-1 on equatorial (dry) facing slopes to 0.0040 day-1 on polar (wet) facing slopes. However, differences in temperature as a result of morning vs afternoon sun on east and west aspects, respectively, (not captured in the aridity metric) resulted in poor prediction of decomposition for the sites located in the intermediate aridity range. Overall the results highlight that relatively small differences in microclimate due to slope orientation can have large effects on decomposition. Future research will aim to refine the aridity metric to better resolve small scale variation in surface temperature which is important when up-scaling decomposition processes to landscapes.

  1. The Morphological Decomposition of Abell 868

    NASA Astrophysics Data System (ADS)

    Driver, S. P.; Odewahn, S. C.; Echevarria, L.; Cohen, S. H.; Windhorst, R. A.; Phillipps, S.; Couch, W. J.

    2003-12-01

    We report on the morphological luminosity functions (LFs) and radial profiles derived for the galaxy population within the rich cluster Abell 868 (z=0.153) based purely on Hubble Space Telescope imaging in F606W. We recover Schechter functions (-24.0early (E/S0) , mid (Sabc), and late (Sd/Irr) type galaxies of1. M*all-5logh0.65=-22.4+0.6-0.6, ?all=-1.27+0.2-0.22. M*E/S0-5logh0.65=-21.6+0.6-0.6, ?E/S0=-0.5+0.2-0.33. M*Sabc-5logh0.65=-21.3+1.0-0.9, ?Sabc=-1.2+0.2-0.2 and4. M*Sd/Irr-5logh0.65=-17.4+0.7-0.7, ?Sd/Irr=-1.4+0.6-0.5. The early, mid, and late types are all consistent with the recent field morphological LFs based on recent analysis of the Sloan Digital Sky Survey Early Data Release. From a detailed error analysis, including clustering of the background population, we note that improved statistics can only come from combining data from many clusters. We also examine the luminosity-density and number-density profiles as a function of morphology and draw the following conclusions: (1) the galaxies responsible for the steep faint-end slope are predominantly of late-type morphology; (2) the cluster core is dominated by elliptical galaxies; (3) the core is devoid of late-type systems; (4) the luminosity density as a function of morphological type is skewed toward early types when compared with the field; (5) up to half of the elliptical galaxies may have formed from the spiral population through core disk-destruction process(es). We believe the most plausible explanation is the conventional one that late types are destroyed during transit through the cluster core and that mid types are converted into early types through a similar process, which destroys the outer disk and results in a more tightly bound population of core elliptical galaxies. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program No. 8203.

  2. Plant roots alter microbial potential for mediation of soil organic carbon decomposition

    NASA Astrophysics Data System (ADS)

    Firestone, M.; Shi, S.; Herman, D.; He, Z.; Zhou, J.

    2014-12-01

    Plant root regulation of soil organic carbon (SOC) decomposition is a key controller of terrestrial C-cycling. Although many studies have tested possible mechanisms underlying plant "priming" of decomposition, few have investigated the microbial mediators of decomposition, which can be greatly influenced by plant activities. Here we examined effects of Avena fatua roots on decomposition of 13C-labeled root litter in a California grassland soil over two simulated growing-seasons. The presence of plant roots consistently suppressed rates of litter decomposition. Reduction of inorganic nitrogen (N) concentration in soil reduced but did not completely relieve this suppressive effect. The presence of plants significantly altered the abundance, composition and functional potential of microbial communities. Significantly higher signal intensities of genes capable of degrading low molecular weight organic compounds (e.g., glucose, formate and malate) were observed in microbial communities from planted soils, while microorganisms in unplanted soils had higher relative abundances of genes involved in degradation of some macromolecules (e.g., hemicellulose and lignin). Additionally, compared to unplanted soils, microbial communities from planted soils had higher signal intensities of proV and proW, suggesting microbial osmotic stress in planted soils. Possible mechanisms for the observed inhibition of decomposition are 1) microbes preferentially using simple substrates from root exudates and 2) soil drying by plant evapotranspiration impairing microbial activity. We propose a simple data-based model suggesting that the impacts of roots, the soil environment, and microbial community composition on decomposition processes result from impacts of these factors on the soil microbial functional gene potential.

  3. NO decomposition over MnâOâ and MnâOâ

    Microsoft Academic Search

    T. Yamashita; A. Vannice

    1996-01-01

    MnâOâ is better than MnâOâ for catalytic NO decomposition; regardless, appreciable activities were not observed below 773 K. For example, at 0.040 atm NO and 773 K, MnâOâ had a specific activity of 3.5 x 10⁻⁴ μmole Nâ\\/s\\/m² and an activation energy of 11 kcal\\/mole, while for MnâOâ comparable values were 6.5 x 10⁻⁵ μmole Nâ\\/s\\/m² and 15 kcal\\/mole, respectively.

  4. UV-bright nearby early type galaxies observed in the mid-infrared: evidence for a multi-stage formation history by way of WISE and GALEX imaging

    E-print Network

    Petty, S M; Jarrett, T H; Blain, A W; Farrah, D G; Rich, R M; Tsai, C -W; Benford, D J; Bridge, C R; Lake, S E; Masci, F J; Wright, E L

    2013-01-01

    In the local Universe, 10% of massive elliptical galaxies are observed to exhibit a peculiar property: a substantial excess of ultraviolet emission (UVX) over what is expected from their old, red stellar populations. Several origins for the UVX have been proposed, including a population of hot young stars, or a population of old, blue horizontal branch or extended horizontal branch (BHB or EHB) stars that have undergone substantial mass loss from their outer atmospheres. We explore the radial distribution of ultraviolet excess (UVX) in a selection of 49 nearby E/S0-type galaxies by measuring the extended photometry in the UV-midIR with GALEX, SDSS and WISE. We compare UV/optical and UV/mid-IR colors with the Flexible Stellar Population Synthesis with EHB models (Conroy & Gunn 2010). We find that combined WISE mid-IR and GALEX UV colors are more effective in distinguishing models than optical colors, and that the UV/mid-IR combination is sensitive to EHB fraction. There are strong color gradients with the ...

  5. Development of a Novel Catalyst for No Decomposition

    SciTech Connect

    Ates Akyurtlu; Jale Akyurtlu

    2007-06-22

    Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one to believe that the Pt/SnO{sub 2} catalysts may have a potential as NO decomposition catalysts in the presence of oxygen. This prediction is also supported by some preliminary data obtained for NO decomposition on a Pt/SnO{sub 2} catalyst in the PI's laboratory. The main objective of the research that is being undertaken is the evaluation of the Pt/SnO{sub 2} catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O{sub 2}, H{sub 2}O, and elevated temperatures. Temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO{sub 2} catalysts having different noble metal concentrations and pretreated under different conditions were done. It is also planned to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. Temperature programmed desorption and temperature controlled reaction runs were made with catalysts containing 15% Pt and 10% Pt on SnO{sub 2}. Catalysts containing 10% Pt resulted in significantly lower activities than 15% PT catalysts. Therefore, in the remainder of the tests 15% Pt/SnO{sub 2} catalysts were used. Isothermal reaction studies were made to elucidate the effects of temperature, oxygen, water vapor, pretreatment temperature, and space velocity on NO dissociation. It was found that the presence of oxygen and water vapor did not affect the activation energy of the NO dissociation reaction indicating the presence of the same rate controlling step for all feed compositions. Activation energy was higher for higher gas velocities suggesting the presence of mass transfer limitations at lower velocities. Presence of oxygen in the feed inhibited the NO decomposition. Having water vapor in the feed did not significantly affect the catalyst activity for catalysts pretreated at 373 K, but significantly reduced catalyst activity for catalysts pretreated at 900 K. Long-term deactivation studies indicated that the catalyst deactivated slowly both with and without the presence of added oxygen in the feed, Deactivation started later in the presence of oxygen. The activities of the catalysts investigated were too low below 1000 K for commercial applications. Their selectivity towards N{sub 2} was good at temperatures above 700 K. A different method for catalyst preparation is needed to improve the catalyst performance.

  6. Decomposition of pentaerythritol tetranitrate [C(CH2ONO2)4] following electronic excitation

    NASA Astrophysics Data System (ADS)

    Yu, Zijun; Bernstein, Elliot R.

    2011-10-01

    We report the experimental and theoretical study of the decomposition of gas phase pentaerythritol tetranitrate (PETN) [C(CH2ONO2)4] following electronic state excitation. PETN has received major attention as an insensitive, high energy explosive; however, the mechanism and dynamics of the decomposition of this material are not clear yet. The initial decomposition mechanism of PETN is explored with nanosecond energy resolved spectroscopy and quantum chemical theory employing the ONIOM algorithm at the complete active space self-consistent field (CASSCF) level. The nitric oxide (NO) molecule is observed as an initial decomposition product from PETN at three UV excitation wavelengths (226, 236, and 248 nm) with a pulse duration of 8 ns. Energies of the three excitation wavelengths coincide with the (0-0), (0-1), and (0-2) vibronic bands of the NO A 2?+ ? X 2? electronic transition, respectively. A unique excitation wavelength independent dissociation channel is observed for PETN, which generates the NO product with a rotationally cold (˜20 K) and a vibrationally hot (˜1300 K) distribution. Potential energy surface calculations at the ONIOM(CASSCF:UFF) level of theory illustrate that conical intersections play an important role in the decomposition mechanism. Electronically excited S1 PETN returns to the ground state through the (S1/S0)CI conical intersection, and undergoes a nitro-nitrite isomerization to generate the NO product.

  7. Pyrogenic carbon decomposition mixed to different litters : a controlled conditions study

    NASA Astrophysics Data System (ADS)

    Andreoli, R.; Abiven, S.

    2009-04-01

    In a recent study, Wardle et al. (2008) showed that the presence of pyrogenic carbon modified litter decomposition dynamics in soil, for boreal conditions. Pyrogenic carbon corresponds to the organic residues left after the incomplete combustion of vegetal biomass. It presents specific properties in term of biological, physical and chemical stability and might play a major role in biogeochemical cycles of soils. The decomposition of a mixture of different organic substrates could be very different from the mathematical average of the same substrates decaying alone. Positive interactions (for example mineral N released from one substrate available for the other one) or negative interactions (for example release of molecules with a biocide effect like polyphenols) have been observed. In an incubation study, we followed decomposition of pyrogenic carbon and of the corresponding original wood (Picea abies) mixed (1:1) to different organic substrates (leaves) with different content of nitrogen and polyphenols. We observed a positive effect of substrates rich in nitrogen on the mixture decomposition and no significant effect with the other substrates. The specific contribution of the char and the wood to the mixture decomposition will be also shown. If confirmed, this mixture interaction would have to be considered in C ecosystem mass balance.

  8. The Effect of the Crayfish Orconectes virilis (Crustacea: Decapoda: Cambaridae) in the Decomposition and Succession of Submerged Small Mammal Carrion

    NASA Astrophysics Data System (ADS)

    de Jong, G. D.; Chadwick, J. W.

    2005-05-01

    The role of the crayfish Orconectes virilis in the decomposition of submerged rat carrion and succession of other benthic macroinvertebrates was experimentally investigated in Slaughterhouse Gulch, a small, urban stream in Littleton, Colorado. Crayfish participation in carrion decomposition significantly altered the decomposition rate of the carrion. Nine carcasses were exposed in anchored minnow traps at three degrees of crayfish access: crayfish always present, crayfish having free access, and crayfish excluded. These three treatments required 23 days, 29 days, and 65 days, respectively, for complete decomposition of the rat carrion (<2% original biomass). Sample variability increased with number of crayfish present, especially as decomposition proceeded. Seven other macroinvertebrate taxa were collected from the carcasses, but their presence or absence could not be correlated with crayfish presence. The leech Haemopis marmoratus was generally the first macroinvertebrate to arrive at the carrion, being present in densities of <5 individuals/carcass early in succession and in larger densities (up to 25 individuals/carcass) after extensive decomposition and exposure of the viscera.

  9. Global decomposition experiment shows soil animal impacts on decomposition are climate-dependent

    PubMed Central

    WALL, DIANA H; BRADFORD, MARK A; ST JOHN, MARK G; TROFYMOW, JOHN A; BEHAN-PELLETIER, VALERIE; BIGNELL, DAVID E; DANGERFIELD, J MARK; PARTON, WILLIAM J; RUSEK, JOSEF; VOIGT, WINFRIED; WOLTERS, VOLKMAR; GARDEL, HOLLEY ZADEH; AYUKE, FRED O; BASHFORD, RICHARD; BELJAKOVA, OLGA I; BOHLEN, PATRICK J; BRAUMAN, ALAIN; FLEMMING, STEPHEN; HENSCHEL, JOH R; JOHNSON, DAN L; JONES, T HEFIN; KOVAROVA, MARCELA; KRANABETTER, J MARTY; KUTNY, LES; LIN, KUO-CHUAN; MARYATI, MOHAMED; MASSE, DOMINIQUE; POKARZHEVSKII, ANDREI; RAHMAN, HOMATHEVI; SABARÁ, MILLOR G; SALAMON, JOERG-ALFRED; SWIFT, MICHAEL J; VARELA, AMANDA; VASCONCELOS, HERALDO L; WHITE, DON; ZOU, XIAOMING

    2008-01-01

    Climate and litter quality are primary drivers of terrestrial decomposition and, based on evidence from multisite experiments at regional and global scales, are universally factored into global decomposition models. In contrast, soil animals are considered key regulators of decomposition at local scales but their role at larger scales is unresolved. Soil animals are consequently excluded from global models of organic mineralization processes. Incomplete assessment of the roles of soil animals stems from the difficulties of manipulating invertebrate animals experimentally across large geographic gradients. This is compounded by deficient or inconsistent taxonomy. We report a global decomposition experiment to assess the importance of soil animals in C mineralization, in which a common grass litter substrate was exposed to natural decomposition in either control or reduced animal treatments across 30 sites distributed from 43°S to 68°N on six continents. Animals in the mesofaunal size range were recovered from the litter by Tullgren extraction and identified to common specifications, mostly at the ordinal level. The design of the trials enabled faunal contribution to be evaluated against abiotic parameters between sites. Soil animals increase decomposition rates in temperate and wet tropical climates, but have neutral effects where temperature or moisture constrain biological activity. Our findings highlight that faunal influences on decomposition are dependent on prevailing climatic conditions. We conclude that (1) inclusion of soil animals will improve the predictive capabilities of region- or biome-scale decomposition models, (2) soil animal influences on decomposition are important at the regional scale when attempting to predict global change scenarios, and (3) the statistical relationship between decomposition rates and climate, at the global scale, is robust against changes in soil faunal abundance and diversity.

  10. Steganography based on pixel intensity value decomposition

    NASA Astrophysics Data System (ADS)

    Abdulla, Alan Anwar; Sellahewa, Harin; Jassim, Sabah A.

    2014-05-01

    This paper focuses on steganography based on pixel intensity value decomposition. A number of existing schemes such as binary, Fibonacci, Prime, Natural, Lucas, and Catalan-Fibonacci (CF) are evaluated in terms of payload capacity and stego quality. A new technique based on a specific representation is proposed to decompose pixel intensity values into 16 (virtual) bit-planes suitable for embedding purposes. The proposed decomposition has a desirable property whereby the sum of all bit-planes does not exceed the maximum pixel intensity value, i.e. 255. Experimental results demonstrate that the proposed technique offers an effective compromise between payload capacity and stego quality of existing embedding techniques based on pixel intensity value decomposition. Its capacity is equal to that of binary and Lucas, while it offers a higher capacity than Fibonacci, Prime, Natural, and CF when the secret bits are embedded in 1st Least Significant Bit (LSB). When the secret bits are embedded in higher bit-planes, i.e., 2nd LSB to 8th Most Significant Bit (MSB), the proposed scheme has more capacity than Natural numbers based embedding. However, from the 6th bit-plane onwards, the proposed scheme offers better stego quality. In general, the proposed decomposition scheme has less effect in terms of quality on pixel value when compared to most existing pixel intensity value decomposition techniques when embedding messages in higher bit-planes.

  11. Determining the degree of peat decomposition - A comparison of different methods

    NASA Astrophysics Data System (ADS)

    Biester, Harald; Knorr, Klaus-Holger; Schellekens, Judith; Basler, Anna; Hermanns, Yvonne-Marie

    2014-05-01

    Peat humification or decomposition is a frequently used proxy to extract past time changes in hydrology and climate from peat bogs. During the past century several methods to determine changes in peat decomposition have been introduced. Most of these methods are operationally defined only and the chemical changes underlying the decomposition process are often poorly understood and lack validation. Due to the chemically undefined nature of many humification analyses the comparison of results obtained by different methods is difficult if not misleading. In this study we compared changes in peat decomposition in cores of two peat bogs (Königsmoor (KK), Kleines Rotes Bruch (KRB)) from the Harz Mountains (Germany) using C/N ratios, Fourier Transform Infrared spectra absorption (FTIR) intensities, Rock Eval® oxygen- and hydrogen indices, ?13C and ?15N isotopic signatures and UV-absorption of NaOH peat extracts. In addition, one of the cores was analysed for changes in the peat's molecular composition using pyrolysis gas chromatography mass spectrometry (pyrolysis-GC-MS). Records of decomposition proxies show similar historical development at both sites, indicating external forcing such as climate as controlling process. Moreover, all decomposition proxies except UV-ABS and ?15N isotopes show similar patterns in their records and thus reflect in different extents signals of decomposition. Pyrolysis-GC-MS analyses of the KK core reveal that changes in peat molecular chemistry are mainly attributed to decomposition processes and to a lesser extend to changes in vegetation. Changes in the abundance of molecular compounds indicate that peat decomposition in the KK bog is mainly characterized by preferential decomposition of phenols and polysaccharides and relative enrichment of aliphatics during drier periods. Enrichment of lignin and other aromatics during decomposition was also observed but showed less variation, and presumably reflects changes in vegetation associated to changes in hydrology of the bogs. Significant correlations with polysaccharide and aliphatic pyrolysis products were found for C/N ratios, FTIR-band intensities and for hydrogen index values, supporting that these decomposition indices provide reasonable information despite their bulk nature. Correlation with oxygen index values and ?13C was lower assumingly indicating carboxylation of the peat during drier periods and enrichment of isotopically lighter peat components during decomposition, respectively. FTIR, C/N ratio, Pyrolysis-GC-MS analyses and Rock Eval hydrogen indices appear to reflect mass loss and related changes in the molecular peat composition during mineralization best. Different to the other investigated proxies, Pyrolysis-GC-MS and FTIR analyses allow disentangling decomposition processes and vegetation changes. UV-ABS measurements of alkaline peat extracts show only weak correlation with other decomposition proxies as they mainly reflect the formation of humic acids through humifcation and to a lesser extend mass loss during mineralization.

  12. Early Failure Detection of Bearing Based on Probabilistic Matching Pursuit

    Microsoft Academic Search

    Jianjun Zhang; Zhongsheng Wang; Jiancang Ma

    2007-01-01

    A signal adaptive time-frequency decomposition to extend matching pursuit algorithm-probabilistic matching pursuit is studied. This method is firstly introduced into early fault diagnosis of rolling bearing. It adopts Gaussian wavelet to construct the time-frequency atoms dictionary. Applying probabilistic matching pursuit, we can accurately extract the early defect features by computing coherence between vibration signals of rolling bearing with inner or

  13. Anomalous Blue Colors in Extremely Isolated Early-Type Galaxies

    NASA Astrophysics Data System (ADS)

    Fuse, Christopher R.

    2009-01-01

    Highly isolated systems provide a baseline for assessing the role of interactions within galaxy evolution. We use the Sloan Digital Sky Survey (SDSS) data release 1 - 5 to identify extremely isolated early-type galaxies (IEGs) in the nearby universe. Redshifts derived from the SDSS spectra permit a robust three-dimensional assessment of the local environment surrounding candidate IEGs. Isolated galaxies are chosen utilizing a projected physical separation of 2.5 Mpc from any neighboring non-dwarf galaxy brighter than M$_{V}$ = $-$16.5. A minimum redshift separation of 350 km s$^{-1}$ between a candidate galaxy and a neighboring was imposed to further insure the candidate's isolation. The IEG sample contains 33 galaxies that exhibit a number of unexpected features. Through the use of a bulge/disk decomposition technique using standard surface photometry, brightness profiles and model-subtracted images were created. Radial profiles of eccentricity, position angle, and surface brightness were employed with the model images to constrain the merger and interaction histories of the IEGs. The presence of shell and fan structures, signatures of recent mergers, were detected in approximately 12% of the sample. Dominant features of the IEG sample are blue colors and active star formation, atypical of normal early-type galaxies. The IEGs would require a substantial reservoir of neutral gas to fuel the levels of on-going star formation observed. We speculate that some of the IEGs may be the remains of a coalesced group of gas-rich dwarf galaxies. Three sample galaxies have red colors and undisturbed morphologies expected of a pristine isolated early-type galaxy formed early in cosmic time. We acknowledge support from NASA's Astrophysical Data Program; grant #NNG05C53G, the GALEX Guest Investigator program, and a Texas Space Grant Consortium Fellowship.

  14. Isothermal Decomposition of Hydrogen Peroxide Dihydrate

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Baragiola, R. A.

    2011-01-01

    We present a new method of growing pure solid hydrogen peroxide in an ultra high vacuum environment and apply it to determine thermal stability of the dihydrate compound that forms when water and hydrogen peroxide are mixed at low temperatures. Using infrared spectroscopy and thermogravimetric analysis, we quantified the isothermal decomposition of the metastable dihydrate at 151.6 K. This decomposition occurs by fractional distillation through the preferential sublimation of water, which leads to the formation of pure hydrogen peroxide. The results imply that in an astronomical environment where condensed mixtures of H2O2 and H2O are shielded from radiolytic decomposition and warmed to temperatures where sublimation is significant, highly concentrated or even pure hydrogen peroxide may form.

  15. Randomized interpolative decomposition of separated representations

    NASA Astrophysics Data System (ADS)

    Biagioni, David J.; Beylkin, Daniel; Beylkin, Gregory

    2015-01-01

    We introduce an algorithm to compute tensor interpolative decomposition (dubbed CTD-ID) for the reduction of the separation rank of Canonical Tensor Decompositions (CTDs). Tensor ID selects, for a user-defined accuracy ?, a near optimal subset of terms of a CTD to represent the remaining terms via a linear combination of the selected terms. CTD-ID can be used as an alternative to or in combination with the Alternating Least Squares (ALS) algorithm. We present examples of its use within a convergent iteration to compute inverse operators in high dimensions. We also briefly discuss the spectral norm as a computational alternative to the Frobenius norm in estimating approximation errors of tensor ID. We reduce the problem of finding tensor IDs to that of constructing interpolative decompositions of certain matrices. These matrices are generated via randomized projection of the terms of the given tensor. We provide cost estimates and several examples of the new approach to the reduction of separation rank.

  16. New evidence favoring multilevel decomposition and optimization

    NASA Technical Reports Server (NTRS)

    Padula, Sharon L.; Polignone, Debra A.

    1990-01-01

    The issue of the utility of multilevel decomposition and optimization remains controversial. To date, only the structural optimization community has actively developed and promoted multilevel optimization techniques. However, even this community acknowledges that multilevel optimization is ideally suited for a rather limited set of problems. It is warned that decomposition typically requires eliminating local variables by using global variables and that this in turn causes ill-conditioning of the multilevel optimization by adding equality constraints. The purpose is to suggest a new multilevel optimization technique. This technique uses behavior variables, in addition to design variables and constraints, to decompose the problem. The new technique removes the need for equality constraints, simplifies the decomposition of the design problem, simplifies the programming task, and improves the convergence speed of multilevel optimization compared to conventional optimization.

  17. Multilevel domain decomposition for electronic structure calculations

    SciTech Connect

    Barrault, M. [EDF R and D, 1 avenue du General de Gaulle, 92141 Clamart Cedex (France) and CERMICS, Ecole Nationale des Ponts et Chaussees, 6 and 8, Avenue Blaise Pascal, Cite Descartes, 77455 Marne-La-Vallee Cedex 2 (France)]. E-mail: maxime.barrault@edf.fr; Cances, E. [CERMICS, Ecole Nationale des Ponts et Chaussees, 6 and 8, Avenue Blaise Pascal, Cite Descartes, 77455 Marne-La-Vallee Cedex 2 (France)]. E-mail: cances@cermics.enpc.fr; Hager, W.W. [Department of Mathematics, University of Florida, Gainesville, FL 32611-8105 (United States)]. E-mail: hager@math.ufl.edu; Le Bris, C. [CERMICS, Ecole Nationale des Ponts et Chaussees, 6 and 8, Avenue Blaise Pascal, Cite Descartes, 77455 Marne-La-Vallee Cedex 2 (France)]. E-mail: lebris@cermics.enpc.fr

    2007-03-01

    We introduce a new multilevel domain decomposition method (MDD) for electronic structure calculations within semi-empirical and density functional theory (DFT) frameworks. This method iterates between local fine solvers and global coarse solvers, in the spirit of domain decomposition methods. Using this approach, calculations have been successfully performed on several linear polymer chains containing up to 40,000 atoms and 200,000 atomic orbitals. Both the computational cost and the memory requirement scale linearly with the number of atoms. Additional speed-up can easily be obtained by parallelization. We show that this domain decomposition method outperforms the density matrix minimization (DMM) method for poor initial guesses. Our method provides an efficient preconditioner for DMM and other linear scaling methods, variational in nature, such as the orbital minimization (OM) procedure.

  18. Covariant gauge fixing and Kuchar decomposition

    E-print Network

    P. Hajicek; J. Kijowski

    1999-08-18

    The symplectic geometry of a broad class of generally covariant models is studied. The class is restricted so that the gauge group of the models coincides with the Bergmann-Komar group and the analysis can focus on the general covariance. A geometrical definition of gauge fixing at the constraint manifold is given; it is equivalent to a definition of a background (spacetime) manifold for each topological sector of a model. Every gauge fixing defines a decomposition of the constraint manifold into the physical phase space and the space of embeddings of the Cauchy manifold into the background manifold (Kuchar decomposition). Extensions of every gauge fixing and the associated Kuchar decomposition to a neighbourhood of the constraint manifold are shown to exist.

  19. Keratin subsidies promote feather decomposition via an increase in keratin-consuming arthropods and microorganisms in bird breeding colonies

    NASA Astrophysics Data System (ADS)

    Sugiura, Shinji; Masuya, Hayato

    2015-06-01

    Resource subsidies are well known to increase population densities of consumers. The decomposition process of these subsidised resources can be influenced by increasing consumer abundance. However, few studies have assessed whether resource subsidies can promote resource decomposition via a population increase in consumers. Here, we examined the effects of keratin subsidies on feather decomposition in egret and heron breeding colonies. Egrets and herons (Ardeidae) frequently breed in inland forests and provide large amounts of keratin materials to the forest floor in the form of feathers of chicks (that die). We compared the decrease in the weights of egret and heron feathers (experimentally placed on the forest floor) over a 12-month period among egret/heron breeding colonies (five sites) and areas outside of colonies (five sites) in central Japan. Of the feathers placed experimentally on forest floors, 92-97 % and 99-100 % in colonies and 47-50 % and 71-90 % in non-colony areas were decomposed after 4 and 12 months, respectively. Then, decomposition rates of feathers were faster in colonies than in areas outside of colonies, suggesting that keratin subsidies can promote feather decomposition in colonies. Field observations and laboratory experiments indicated that keratin-feeding arthropods and keratinophilic fungi played important roles in feather decomposition. Therefore, scavenging arthropods and keratinophilic fungi, which dramatically increased in egret and heron breeding colonies, could accelerate the decomposition of feathers supplied to the forest floor of colonies.

  20. March n b120102 Rfection des circulations et mise en conformit DECOMPOSITION DES PRIX FORFAITAIRE

    E-print Network

    Paris 7 - Denis Diderot, Université

    1/2 Marché n° b120102 ­ Réfection des circulations et mise en conformité DECOMPOSITION DES PRIX FORFAITAIRE Rez-de-chaussée DESIGNATION OBSERVATIONS UNITE QUANTITE PRIX U PRIX HT PRIX TTC INSTALLATION DE QUANTITE PRIX U PRIX HT PRIX TTC INSTALLATION DE CHANTIER DEMOLITION Dépose de blocs portes Dépose impostes

  1. Catalytic decomposition of N 2O over monolithic supported noble metal-transition metal oxides

    Microsoft Academic Search

    Viviane Boissel; Saad Tahir; Carolyn Ann Koh

    2006-01-01

    The decomposition of nitrous oxide to nitrogen and oxygen using a series of monolithic (ceria-alumina washcoated cordierite) supported transition metal (Cu, Fe, Co, Ni, Mn) and noble metal (Ir, Rh) oxide catalysts has been studied using gas chromatography. The effect of combining a transition metal with a noble metal has also been investigated. A synergetic effect was observed between transition

  2. Volume Scattering Modeling in PolSAR Decompositions: Study of ALOS PALSAR Data Over Boreal Forest

    Microsoft Academic Search

    Oleg Antropov; Yrjö Rauste; Tuomas Hame

    2011-01-01

    Model-based approaches for decomposing polarimet- ric backscatter data from boreal forest are discussed in this paper. Several model-based decompositions are analyzed with respect for the most accurate estimation of the volume scattering com- ponent. A novel generalized model for description of the volume contribution is proposed when observed backscatter from forest indicates that media does not follow azimuthal symmetry case.

  3. Chemical promotional effect of gold added to palladium supported on cerium oxide in catalytic methanol decomposition

    Microsoft Academic Search

    Mahendra P Kapoor; Yuichi Ichihashi; Toshie Nakamori; Yasuyuki Matsumura

    2004-01-01

    Addition of gold to palladium by simultaneous deposition–precipitation on cerium oxide increases the catalytic activity for methanol decomposition to carbon monoxide and hydrogen at 180°C. No significant promotional effect was observed by addition of rhodium or iridium to palladium. The electronic state or dispersion of palladium is unchanged by the addition of gold, suggesting presence of new active sites. Bimetallic

  4. Nitrogen Amendment Stimulated Decomposition of Maize Straw-Derived Biochar in a Sandy Loam Soil: A Short-Term Study

    PubMed Central

    Lu, Weiwei; Ding, Weixin; Zhang, Junhua; Zhang, Huanjun; Luo, Jiafa; Bolan, Nanthi

    2015-01-01

    This study examined the effect of nitrogen (N) on biochar stability in relation to soil microbial community as well as biochar labile components using ?13C stable isotope technology. A sandy loam soil under a long-term rotation of C3 crops was amended with biochar produced from maize (a C4 plant) straw in absence (BC0) and presence (BCN) of N and monitored for dynamics of carbon dioxide (CO2) flux, phospholipid fatty acids (PLFAs) profile and dissolved organic carbon (DOC) content. N amendment significantly increased the decomposition of biochar during the first 5 days of incubation (P < 0.05), and the proportions of decomposed biochar carbon (C) were 2.30% and 3.28% in BC0 and BCN treatments, respectively, during 30 days of incubation. The magnitude of decomposed biochar C was significantly (P < 0.05) higher than DOC in biochar (1.75%) and part of relatively recalcitrant biochar C was mineralized in both treatments. N amendment increased soil PLFAs concentration at the beginning of incubation, indicating that microorganisms were N-limited in test soil. Furthermore, N amendment significantly (P < 0.05) increased the proportion of gram-positive (G+) bacteria and decreased that of fungi, while no noticeable changes were observed for gram-negative (G?) bacteria and actinobacteria at the early stage of incubation. Our results indicated that N amendment promoted more efficiently the proliferation of G+ bacteria and accelerated the decomposition of relatively recalcitrant biochar C, which in turn reduced the stability of maize straw-derived biochar in test soil. PMID:26192282

  5. Canonical information flow decomposition among neural structure subsets

    PubMed Central

    Takahashi, Daniel Y.; Baccalá, Luiz A.; Sameshima, Koichi

    2014-01-01

    Partial directed coherence (PDC) and directed coherence (DC) which describe complementary aspects of the directed information flow between pairs of univariate components that belong to a vector of simultaneously observed time series have recently been generalized as bPDC/bDC, respectively, to portray the relationship between subsets of component vectors (Takahashi, 2009; Faes and Nollo, 2013). This generalization is specially important for neuroscience applications as one often wishes to address the link between the set of time series from an observed ROI (region of interest) with respect to series from some other physiologically relevant ROI. bPDC/bDC are limited, however, in that several time series within a given subset may be irrelevant or may even interact opposingly with respect to one another leading to interpretation difficulties. To address this, we propose an alternative measure, termed cPDC/cDC, employing canonical decomposition to reveal the main frequency domain modes of interaction between the vector subsets. We also show bPDC/bDC and cPDC/cDC are related and possess mutual information rate interpretations. Numerical examples and a real data set illustrate the concepts. The present contribution provides what is seemingly the first canonical decomposition of information flow in the frequency domain. PMID:24910609

  6. Spectral decomposition by genetic forward modelling

    NASA Astrophysics Data System (ADS)

    McIntosh, S. W.; Diver, D. A.; Judge, P. G.; Charbonneau, P.; Ireland, J.; Brown, J. C.

    1998-10-01

    We discuss the analysis of real and simulated line spectra using a genetic forward modelling technique. We show that this Genetic Algorithm (GA) based technique experiences none of the user bias or systematic problems that arise when faced with poorly sampled or noisy data. An important feature of this technique is the ease with which rigid a priori constraints can be applied to the data. These constraints make the GA decomposition much more accurate and stable, especially at the limit of instrumental resolution, than decomposition algorithms commonly in use.

  7. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2011-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  8. Convergence Analysis of a Domain Decomposition Paradigm

    SciTech Connect

    Bank, R E; Vassilevski, P S

    2006-06-12

    We describe a domain decomposition algorithm for use in several variants of the parallel adaptive meshing paradigm of Bank and Holst. This algorithm has low communication, makes extensive use of existing sequential solvers, and exploits in several important ways data generated as part of the adaptive meshing paradigm. We show that for an idealized version of the algorithm, the rate of convergence is independent of both the global problem size N and the number of subdomains p used in the domain decomposition partition. Numerical examples illustrate the effectiveness of the procedure.

  9. Excited electronic state decomposition mechanisms and dynamics of nitramine energetic materials and model systems

    NASA Astrophysics Data System (ADS)

    Greenfield, Margo

    Energetic materials play an important role in aeronautics, the weapon industry, and the propellant industry due to their broad applications as explosives and fuels. RDX (1,3,5-trinitrohexahydro-s-triazine), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), and CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) are compounds which contain high energy density. Although RDX and HMX have been studied extensively over the past several decades a complete understanding of their decomposition mechanisms and dynamics is unknown. Time of flight mass spectroscopy (TOFMS) UV photodissociation (ns) experiments of gas phase RDX, HMX, and CL-20 generate the NO molecule as the initial decomposition product. Four different vibronic transitions of the initial decomposition product, the NO molecule, are observed: A2Sigma(upsilon'=0)?X 2pi(upsilon"=0,1,2,3). Simulations of the rovibronic intensities for the A?X transitions demonstrate that NO dissociated from RDX, HMX, and CL-20 is rotationally cold (˜20 K) and vibrationally hot (˜1800 K). Conversely, experiments on the five model systems (nitromethane, dimethylnitramine (DMNA), nitropyrrolidine, nitropiperidine and dinitropiperazine) produce rotationally hot and vibrationally cold spectra. Laser induced fluorescence (LIF) experiments are performed to rule out the possible decomposition product OH, generated along with NO, perhaps from the suggested HONO elimination mechanism. The OH radical is not observed in the fluorescence experiments, indicating the HONO decomposition intermediate is not an important pathway for the excited electronic state decomposition of cyclic nitramines. The NO molecule is also employed to measure the dynamics of the excited state decomposition. A 226 nm, 180 fs light pulse is utilized to photodissociate the gas phase systems. Stable ion states of DMNA and nitropyrrolidine are observed while the energetic materials and remaining model systems present the NO molecule as the only observed product. Pump-probe transients of the resonant A?X (0-0) transition of the NO molecule show a constant signal indicating these materials decompose faster than the time duration of the 226 nm laser light. Calculational results together with the experimental results indicate the energetic materials decompose through an internal conversion to very highly excited (˜5 eV of vibrational energy) vibrational states of their ground electronic state, while the model systems follow an excited electronic state decomposition pathway.

  10. Explosive decomposition of hexogen monocrystals induced by a pulsed electron beam

    NASA Astrophysics Data System (ADS)

    Aduev, B. P.; Belokurov, G. M.; Grechin, S. S.; Liskov, I. Yu.

    2014-12-01

    Investigations of explosive decomposition of hexogen monocrystals under exposure to a high-current electron beam (0.25 MeV, 20 ns, 15 J/cm2) are conducted for the first time. The luminescence kinetics and spectra are measured in real time. It is shown that luminescence of crystals is observed at the time of electron beam action; explosive decomposition occurs within the microsecond time interval. The thermal nature of explosive luminescence is established using spectral pyrometry. The temperature of explosion is determined to be T = 3500 K.

  11. Isotropic photo-decomposition of spherical organic polymers on rutile TiO?(110) surfaces.

    PubMed

    Ishida, Nobuyuki; Iwasaki, Tamaki; Fujita, Daisuke

    2011-04-15

    We observed the photo-decomposition process of polystyrene latex (PSL) spheres on a rutile TiO?(110) single crystal surface by using atomic force microscopy. During the decomposition process, both the height and width of the PSL spheres linearly decreased with the irradiation time in a similar way from the beginning, suggesting that the PSL spheres are isotropically decomposed. This indicates that the interface between the PSL spheres and the TiO? surface is not a dominant reaction site, as expected from normal photocatalytic reactions. PMID:21389569

  12. Spatial decomposition of on-nucleus spectra of quasar host galaxies

    E-print Network

    Knud Jahnke; Lutz Wisotzki; Frederic Courbin; Geraldine Letawe

    2007-02-13

    In order to study the host galaxies of type 1 (broad-line) quasars, we present a semi-analytic modelling method to decompose the on-nucleus spectra of quasars into nuclear and host galaxy channels. The method uses the spatial information contained in long-slit or slitlet spectra. A routine determines the best fitting combination of the spatial distribution of the point like nucleus and extended host galaxy. Inputs are a simultaneously observed PSF, and external constraints on galaxy morphology from imaging. We demonstrate the capabilities of the method to two samples of a total of 18 quasars observed with EFOSC at the ESO 3.6m telescope and FORS1 at the ESO VLT. ~50% of the host galaxies with sucessful decomposition show distortions in their rotation curves or peculiar gas velocities above normal maximum velocities for disks. This is consistent with the fraction from optical imaging. All host galaxies have quite young stellar populations, typically 1-2 Gyr. For the disk dominated hosts these are consistent with their inactive counterparts, the luminosity weighted stellar ages are much younger for the bulge dominated hosts, compared to inactive early type galaxies. While this presents further evidence for a connection of galaxy interaction and AGN activity for half of the sample, this is not clear for the other half: These are often undistorted disk dominated host galaxies, and interaction on a smaller level might be detected in deeper high-resolution images or deeper spectroscopic data. The velocity information does not show obvious signs for large scale outflows triggered by AGN feedback - the data is consistent with velocity fields created by galaxy interaction.

  13. First estimate of the value of the instrumental polarization of the RadioAstron space radio telescope using the results of an early scientific program for observing active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Pashchenko, I. N.; Kovalev, Yu. Yu.; Voitsik, P. A.

    2015-05-01

    To interpret radio interferometric observations sensitive to linear polarization it is necessary to take into account the effect of instrumental or "parasitic" polarization. In the case of ground-space very-long-baseline interferometry, this procedure involves a session of polarization-sensitive mapping with the sufficient number of ground stations and sufficiently small projections of ground-space baselines. In the paper, the problem of estimating the value of the instrumental polarization of the Spectr-R space radio telescope of the RadioAstron project using the results of the early scientific program for observing active galactic nuclei is addressed. We use a statistical approach to estimate the value of the instrumental polarization associated with the analysis of already obtained to present time intermediate results of the review of brightness temperatures. Estimates obtained for the frequency bands C and L (95% probability intervals [0.0646, 0.1267] and [0.0945, 0.1736] for 6 and 18 cm, respectively) suggest that the instrumental polarization of the radio telescope does not exceed the values typical for the ground VLBI stations.

  14. Combination of High Rate, Real-Time GNSS and Accelerometer Observations and Rapid Seismic Event Notification for Earthquake Early Warning and Volcano Monitoring with a Focus on the Pacific Rim.

    NASA Astrophysics Data System (ADS)

    Zimakov, L. G.; Passmore, P.; Raczka, J.; Alvarez, M.; Jackson, M.

    2014-12-01

    Scientific GNSS networks are moving towards a model of real-time data acquisition, epoch-by-epoch storage integrity, and on-board real-time position and displacement calculations. This new paradigm allows the integration of real-time, high-rate GNSS displacement information with acceleration and velocity data to create very high-rate displacement records. The mating of these two instruments allows the creation of a new, very high-rate (200 sps) displacement observable that has the full-scale displacement characteristics of GNSS and high-precision dynamic motions of seismic technologies. It is envisioned that these new observables can be used for earthquake early warning studies, volcano monitoring, and critical infrastructure monitoring applications. Our presentation will focus on the characteristics of GNSS, seismic, and strong motion sensors in high dynamic environments, including historic earthquakes in Southern California and the Pacific Rim, replicated on a shake table, over a range of displacements and frequencies. We will explore the optimum integration of these sensors from a filtering perspective including simple harmonic impulses over varying frequencies and amplitudes and under the dynamic conditions of various earthquake scenarios. In addition we will discuss implementation of a Rapid Seismic Event Notification System that provides quick delivery of digital data from seismic stations to the acquisition and processing center and a full data integrity model for real-time earthquake notification that provides warning prior to significant ground shaking.

  15. On the two remaning issues in the gauge-invariant decomposition problem of the nucleon spin

    NASA Astrophysics Data System (ADS)

    Wakamatsu, M.

    2015-05-01

    The question whether the total angular momentum of the gluon in the nucleon can be decomposed into its spin and orbital parts without conflict with the gauge-invariance principle has been an object of long-lasting debate. Despite a remarkable progress achieved through the recent intensive researches, the following two issues still remains to be clarified more transparently. The first issue is to resolve the apparent conflict between the proposed gauge-invariant decomposition of the total gluon angular momentum and the textbook statement that the total angular momentum of the photon cannot be gauge-invariantly decomposed into its spin and orbital parts. We show that this problem is also intimately connected with the uniqueness or nonuniqueness problem of the nucleon spin decomposition. The second practically more important issue is: among the two physically inequivalent decompositions of the nucleon spin, i.e. the "canonical" type decomposition and the "mechanical" type decomposition, which can we say is more physical or closer to direct observation? In the present paper, we try to answer both these questions as clearly as possible.

  16. Photo-fragmentation of the closo-carboranes Part 1: Energetics of Decomposition

    SciTech Connect

    Kilcoyne, Arthur L; Feng, Danqin; Liu, Jing; Hitchcock, Adam P.; Kilcoyne, A.L. David; Tyliszczak, Tolek; Riehs, Norman F.; Rühl, Eckart; Bozek, John D.; McIlroy, David; Dowben, Peter A.

    2007-11-09

    The ionic fragmentation following B 1s and C 1s excitation of three isomeric carborane cage compounds [closo-dicarbadodecaboranes: orthocarborane (1,2-C2B10H12), metacarborane (1,7-C2B10H12), and paracarborane (1,12-C2B10H12)], is compared with the energetics of decomposition. The fragmentation yields for all three molecules are quite similar. Thermodynamic cycles are constructed for neutral and ionic species in an attempt to systemically characterize single ion closo-carborane creation and fragmentation processes. Lower energy decomposition processes are favored. Among the ionic species, the photon induced decomposition isdominated by BH+ and BH2+ fragment loss. Changes in ion yield associated with core to bound excitations are observed.

  17. Polyhedral decompositions, essential surfaces and colored Jones knot polynomials

    E-print Network

    Kalfagianni, Efstratia

    Polyhedral decompositions, essential surfaces and colored Jones knot polynomials joint with D at each vertex. Quantum Topology Knot invariants esp. colored Jones polynomials Geometric topology spanned by the knot... Create polyhedral decomposition of surface complements... Ribbon graphs to Jones

  18. TRIANGLE-SHAPED DC CORONA DISCHARGE DEVICE FOR MOLECULAR DECOMPOSITION

    EPA Science Inventory

    The paper discusses the evaluation of electrostatic DC corona discharge devices for the application of molecular decomposition. A point-to-plane geometry corona device with a rectangular cross section demonstrated low decomposition efficiencies in earlier experimental work. The n...

  19. Thermal decomposition study of hydroxylamine nitrate during storage and handling 

    E-print Network

    Zhang, Chuanji

    2007-09-17

    decomposition behavior under various conditions and proposed isothermal aging testing and kinetic-based simulation to determine safety boundaries for HAN storage and handling. Specifically, HAN decomposition in the presence of glass, titanium, stainless steel...

  20. Generalized spectral decomposition method for solving stochastic finite element equations

    E-print Network

    Paris-Sud XI, Université de

    Generalized spectral decomposition method for solving stochastic finite element equations equations, Stochastic Finite Element, Generalized Spectral Decomposition, Invariant Subspace problem obtained by solving a large system of equations. These methods, which lead to high quality predictions

  1. A dimensional decomposition method for stochastic fracture mechanics

    E-print Network

    Rahman, Sharif

    -integral and probability of fracture initiation for various cases including material gradation characteristics density of J-integral; Probability of fracture initiation; Decomposition method; Univariate decomposition and provides probabilistic characteristics of fracture initiation and growth of an existing crack, real

  2. Multi-material decomposition of spectral CT images

    NASA Astrophysics Data System (ADS)

    Mendonça, Paulo R. S.; Bhotika, Rahul; Maddah, Mahnaz; Thomsen, Brian; Dutta, Sandeep; Licato, Paul E.; Joshi, Mukta C.

    2010-04-01

    Spectral Computed Tomography (Spectral CT), and in particular fast kVp switching dual-energy computed tomography, is an imaging modality that extends the capabilities of conventional computed tomography (CT). Spectral CT enables the estimation of the full linear attenuation curve of the imaged subject at each voxel in the CT volume, instead of a scalar image in Hounsfield units. Because the space of linear attenuation curves in the energy ranges of medical applications can be accurately described through a two-dimensional manifold, this decomposition procedure would be, in principle, limited to two materials. This paper describes an algorithm that overcomes this limitation, allowing for the estimation of N-tuples of material-decomposed images. The algorithm works by assuming that the mixing of substances and tissue types in the human body has the physicochemical properties of an ideal solution, which yields a model for the density of the imaged material mix. Under this model the mass attenuation curve of each voxel in the image can be estimated, immediately resulting in a material-decomposed image triplet. Decomposition into an arbitrary number of pre-selected materials can be achieved by automatically selecting adequate triplets from an application-specific material library. The decomposition is expressed in terms of the volume fractions of each constituent material in the mix; this provides for a straightforward, physically meaningful interpretation of the data. One important application of this technique is in the digital removal of contrast agent from a dual-energy exam, producing a virtual nonenhanced image, as well as in the quantification of the concentration of contrast observed in a targeted region, thus providing an accurate measure of tissue perfusion.

  3. Early Cottons

    E-print Network

    Bennett, R. L. (Robert Love)

    1904-01-01

    TEXAS AGRICULTURAL EXPERIMENT STATIONS BULLETIN No. 75 COTTON INVESTIGATIONS OF THE BUREAU OF PLANT INDUSTRY, U. S. DEPARTMENT OF AGRICULTURE AND THE TEXAS EXPERIMENT STATION EARLY COTTONS POSTOFFICE: COLLEGE STATION, BRAZOS COUNTY, TEXAS... ........................... F. R. MARSHALL. .Animal Husbandry EDWARD C. GREEN, B. S.. ................. .Assistant Horticultt~rist .................................. G. S. FRAPS. .Associate Chemist R. L. BENNETT. ................................ .Cotton Specialist 0. M...

  4. Early Math.

    ERIC Educational Resources Information Center

    Van Nuys, Ute Elisabeth

    1986-01-01

    Presents reviews of the following mathematics software designed to teach young children counting, number recognition, visual discrimination, matching, addition, and subtraction skills; Stickybear Numbers, Learning with Leeper, Getting Ready to Read and Add, Counting Parade, Early Games for Young Children, Charlie Brown's 1,2,3's, Let's Go Fishing,…

  5. Viscosity and dissipation - early stages

    E-print Network

    P. Bozek

    2009-01-15

    A very early start up time of the hydrodynamic evolution is needed in order to reproduce observations from relativistic heavy-ion collisions experiments. At such early times the systems is still not locally equilibrated. Another source of deviations from local equilibrium is the viscosity of the fluid. We study these effects at very early times to obtain a dynamical prescription for the transition from an early 2-dimensional expansion to a nearly equilibrated 3-dimensional expansion at latter stages. The role of viscosity at latter stages of the evolution is also illustrated.

  6. Layer tracking asymptotics and domain decomposition

    SciTech Connect

    Brown, D.L. (Los Alamos National Lab., NM (USA)); Chin, R.C.Y. (Indiana Univ.-Purdue Univ., Indianapolis, IN (USA)); Hedstrom, G.W. (Lawrence Livermore National Lab., CA (USA)); Manteuffel, T.A. (Colorado Univ., Denver, CO (USA))

    1990-01-01

    In this paper we present a preliminary report on our work on the tracking of internal layers in a singularly-perturbed convection-diffusion equation. We show why such tracking may be desirable, and we also show how to do it using domain decomposition based on asymptotic analysis. 16 refs.

  7. Temperature programmed decomposition of thorium nitrate pentahydrate

    NASA Astrophysics Data System (ADS)

    Dash, S.; Kamruddin, M.; Ajikumar, P. K.; Tyagi, A. K.; Raj, Baldev; Bera, Santanu; Narasimhan, S. V.

    2000-02-01

    Temperature programmed decomposition (TPD) of thorium nitrate pentahydrate has been studied using evolved gas analysis-mass spectrometry (EGA-MS) in the temperature range 300-1200 K. A thermogravimetric (TGA) investigation was also carried out in the same temperature range. Complexity of the TGA decomposition profile was resolved through use of EGA-MS data. The activation energies and pre-exponential factors were determined for various gas release stages from the fractional extent of decomposition plots. Residues left over after each decomposition stage were analysed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The XRD investigations revealed formation of a nanocrystalline thoria intermediate product, ultimately agglomerating to a microcrystalline phase. The XPS investigations indicated systematic alteration in the chemical environment around the thorium atom while the Th 4+ oxidation state remained unchanged. This was further corroborated from the analysis of shake-up satellites of Th (4f 5/2) spectra. The O/Th ratios for various intermediate products were also determined.

  8. Temperature programmed decomposition of uranyl nitrate hexahydrate

    NASA Astrophysics Data System (ADS)

    Dash, S.; Kamruddin, M.; Bera, Santanu; Ajikumar, P. K.; Tyagi, A. K.; Narasimhan, S. V.; Raj, Baldev

    1999-01-01

    Temperature programmed decomposition (TPD) of uranyl nitrate hexahydrate has been studied using evolved gas analysis mass spectrometry (EGA-MS) in the temperature range 300-1400 K. Thermogravimetric (TGA) investigations were performed in the temperature range 300-1100 K. An attempt has been made to resolve the complexity of decomposition behaviour through suitable comparison of TGA and EGA-MS data. Kinetic control regimes for various decomposition stages could be deduced from EGA-MS data. The corresponding activation energies and frequency factors were also evaluated. Kinetics based on random nucleation and diffusion was found to be rate controlling. The residue left over after each decomposition stage was analysed by XRD and XPS to determine structure and composition. The ultimate product was found to be a mixture of UO 3H 1.17 and U 3O 8: the former being a topotactic hydrogen spill over compound of UO 3. Complete conversion of this residue to U 3O 8 was noticed during ion beam exposure of the residue which was performed in the course of XPS investigations.

  9. Additive Decompositions, Random Allocations, and Threshold Phenomena.

    E-print Network

    Louchard, Guy

    not unique; further, if (J; K) is a decomposition of I; then min I = minJ + minK; and since any 0 #20; i #20; min I can be written as j + k with 0 #20; j #20; minJ and 0 #20; k #20; minK; resulting in (I i) = (J

  10. Perceptual decomposition of virtual haptic surfaces

    Microsoft Academic Search

    Louis B. Rosenberg; Bernard D. Adelstein

    1993-01-01

    The analysis and construction of virtual haptic surfaces are considered from a perceptual point of view rather than from the dynamics and controls approach of prior work. The authors developed a perceptual decomposition of surface contact sensation by examining three qualities associated with the different stages of interaction with a haptic wall simulation. These qualities are the crispness of initial

  11. Benzene generation from phenylborate decomposition in saltstone

    Microsoft Academic Search

    2000-01-01

    High Level Waste Engineering requested SRTC to determine the effect of tetraphenylborate (TPB), triphenylboron (3PB), diphenylborine acid (2PB), and phenylboronic acid (1PB) on the Saltstone process. A previous SRTC report documented benzene evolution from phenylborate decomposition over 91 days, 28 day toxic characteristic leaching procedure (TCLP) results and interactions between phenylborates and components in the saltstone dry chemicals. The ITP

  12. Matching of large images through coupled decomposition.

    PubMed

    Sidiropoulos, Panagiotis; Muller, Jan-Peter

    2015-07-01

    In this paper, we address the problem of fast and accurate extraction of points that correspond to the same location (named tie-points) from pairs of large-sized images. First, we conduct a theoretical analysis of the performance of the full-image matching approach, demonstrating its limitations when applied to large images. Subsequently, we introduce a novel technique to impose spatial constraints on the matching process without employing subsampled versions of the reference and the target image, which we name coupled image decomposition. This technique splits images into corresponding subimages through a process that is theoretically invariant to geometric transformations, additive noise, and global radiometric differences, as well as being robust to local changes. After presenting it, we demonstrate how coupled image decomposition can be used both for image registration and for automatic estimation of epipolar geometry. Finally, coupled image decomposition is tested on a data set consisting of several planetary images of different size, varying from less than one megapixel to several hundreds of megapixels. The reported experimental results, which includes comparison with full-image matching and state-of-the-art techniques, demonstrate the substantial computational cost reduction that can be achieved when matching large images through coupled decomposition, without at the same time compromising the overall matching accuracy. PMID:25751865

  13. 1 SHARP HOMOLOGY DECOMPOSITIONS FOR CLASSIFYING ...

    E-print Network

    1997-12-15

    Here we go further along the same lines. Bousfield and Kan ... Call a homology decomposition sharp if its spectral sequence collapses onto the vertical axis in ... whose value (G/H)hG at an object G/H has the homotopy type of BH. The natural.

  14. Separable Approximations and Decomposition Methods for the ...

    E-print Network

    2013-08-30

    Aug 30, 2013 ... In this paper we study decomposition methods based on separable .... topology design [21], solving linear systems of equations [9] and group ... Moreover, we are interested in the case when n is very large ...... [9] Yin Tat Lee and Aaron Sidford. ... In Operations Research Proceedings 2011, pages 27–32.

  15. Automated Decomposition on Heterogeneous Clusters of

    E-print Network

    Peisert, Sean

    Sputnik: Automated Decomposition on Heterogeneous Clusters of Multiprocessors Sean Philip Peisert. Most are clusters of multiprocessors. · A multiprocessor is a shared-memory machine whereas Cache L2 Cache Processor 3 L1 Cache L2 Cache Bus #12;Copyright © 2000 Sean Philip Peisert Clusters

  16. Angular Momentum Decomposition for an Electron

    E-print Network

    Matthias Burkardt; Hikmat BC

    2008-12-09

    We calculate the orbital angular momentum of the `quark' in the scalar diquark model as well as that of the electron in QED (to order $\\alpha$). We compare the orbital angular momentum obtained from the Jaffe-Manohar decomposition to that obtained from the Ji relation and estimate the importance of the vector potential in the definition of orbital angular momentum.

  17. Angular Momentum Decomposition for an Electron

    SciTech Connect

    Burkardt, Matthias; BC, Hikmat

    2009-01-01

    We calculate the orbital angular momentum of the `quark' in the scalar diquark model as well as that of the electron in QED (to order $\\alpha$). We compare the orbital angular momentum obtained from the Jaffe-Manohar decomposition to that obtained from the Ji relation and estimate the importance of the vector potential in the definition of orbital angular momentum.

  18. Wavelet Decomposition Approaches to Statistical Inverse Problems

    E-print Network

    Abramovich, Felix

    for such inverse problems do not perform satis- factorily when is spatially inhomogeneous. One existing nonlinear inverse problem for the problem of estimating from noisy data in the model (1). Many such problems fallWavelet Decomposition Approaches to Statistical Inverse Problems BY F. ABRAMOVICH Department

  19. Layer tracking, asymptotics, and domain decomposition

    NASA Technical Reports Server (NTRS)

    Brown, D. L.; Chin, R. C. Y.; Hedstrom, G. W.; Manteuffel, T. A.

    1991-01-01

    A preliminary report is presented on the work on the tracking of internal layers in a singularly-perturbed convection-diffusion equation. It is shown why such tracking may be desirable, and it is also shown how to do it using domain decomposition based on asymptotic analysis.

  20. Bayesian Inference with Probability Matrix Decomposition Models.

    ERIC Educational Resources Information Center

    Meulders, Michel; De Boeck, Paul; Van Mechelen, Iven; Gelman, Andrew; Maris, Eric

    2001-01-01

    Presents a fully Bayesian analysis for the Probability Matrix Decomposition (PMD) model using the Gibbs sampler. Identifies the advantages of this approach and illustrates the approach by applying the PMD model to opinions of respondents from different countries concerning the possibility of contracting AIDS in a specific situation. (SLD)

  1. Management intensity alters decomposition via biological pathways

    E-print Network

    Cleveland, Cory

    and activity. We measured decomposition rates, changes in litter chemistry, extracellular enzyme activity in regulating soil organic matter storage, our objectives were to determine the potential effects, and influence litter chem- istry in ways that could have important and long-term effects on soil organic matter

  2. Noise reduction by multiplicative waveforms decomposition

    Microsoft Academic Search

    Amina SERIR; Boualem SANSAL

    2003-01-01

    This paper introduces a novel multiplicative noise reduction method based on a particular association of structural and statistical analysis. The structural analysis is performed by a new, multiplicative matching pursuit decomposition (MMPD), that decomposes images containing the intrinsic variation into a nonlinear expansion of waveforms selected from a dictionary of functions. This selection is made in such a way to

  3. Database Decomposition into Fourth Normal Form

    Microsoft Academic Search

    Gösta Grahne; Kari-jouko Räihä

    1983-01-01

    We present an algorithm that decom- poses a database scheme when the dependency set contains functional and multivalued dependencies. The schemes in the resulting decomposition are in fourth normal form and have a lossless join. Our algorithm does not impose restrictions on the allowed set of dependencies, and it never re- quires the computation of the full closure of the

  4. Improved Distributed Algorithms for SCC Decomposition

    Microsoft Academic Search

    Jiri Barnat; Jakub Chaloupka; Jaco Van De Pol; I. Cerna; B. R. H. M. Haverkort

    2008-01-01

    We study and improve the OBF technique [Barnat, J. and P.Moravec, Parallel algorithms for finding SCCs in implicitly given graphs, in: Proceedings of the 5th International Workshop on Parallel and Distributed Methods in Verification (PDMC 2006), LNCS (2007)], which was used in distributed algorithms for the decomposition of a partitioned graph into its strongly connected components. In particular, we introduce

  5. Decomposition of protein tryptophan fluorescence spectra into log-normal components. I. Decomposition algorithms.

    PubMed Central

    Burstein, E A; Abornev, S M; Reshetnyak, Y K

    2001-01-01

    Two algorithms of decomposition of composite protein tryptophan fluorescence spectra were developed based on the possibility that the shape of elementary spectral component could be accurately described by a uniparametric log-normal function. The need for several mathematically different algorithms is dictated by the fact that decomposition of spectra into widely overlapping smooth components is a typical incorrect problem. Only the coincidence of components obtained with various algorithms can guarantee correctness and reliability of results. In this paper we propose the following algorithms of decomposition: (1) the SImple fitting procedure using the root-Mean-Square criterion (SIMS) operating with either individual emission spectra or sets of spectra measured with various quencher concentrations; and (2) the pseudo-graphic analytical procedure using a PHase plane in coordinates of normalized emission intensities at various wavelengths (wavenumbers) and REsolving sets of spectra measured with various Quencher concentrations (PHREQ). The actual experimental noise precludes decomposition of protein spectra into more than three components. PMID:11509382

  6. Nanosecond time-resolved and steady-state infrared studies of photoinduced decomposition of TATB at ambient and elevated pressure.

    PubMed

    Glascoe, Elizabeth A; Zaug, Joseph M; Armstrong, Michael R; Crowhurst, Jonathan C; Grant, Christian D; Fried, Laurence E

    2009-05-21

    The time scale and/or products of photoinduced decomposition of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) were investigated at ambient pressure and compared with products formed at 8 GPa. Ultrafast time-resolved infrared and steady-state Fourier transform IR (FTIR) spectroscopies were used to probe TATB and its products after photoexcitation with a 5 ns pulse of 532 nm light. At ambient pressure, transient spectra of TATB indicate that the molecule has significantly decomposed within 60 ns; transient spectra also indicate that formation of CO(2), an observed decomposition product, is complete within 30-40 mus. Proof of principle time-resolved experiments at elevated pressures were performed and are discussed briefly. Comparison of steady-state FTIR spectra obtained at ambient and elevated pressure (ca. 8 GPa) indicate that the decomposition products vary with pressure. We find evidence for water as a decomposition product only at elevated pressure. PMID:19438271

  7. Effect of carcass size on rate of decomposition and arthropod succession patterns.

    PubMed

    Hewadikaram, K A; Goff, M L

    1991-09-01

    Decomposition studies were conducted using two carcasses of domestic pigs, Sus scrofa L., 8.4 kg and 15.1 kg in weight, to determine the effects of carcass size on the rate of decomposition, composition of the arthropod fauna, and succession patterns. A total of 46 arthropod taxa were recovered during this study. No size-related differences were observed between carcasses with respect to composition of the arthropod fauna or patterns of succession. A greater number of arthropods were observed attracted to the 15.1-kg carcass, and the rate of decomposition observed was more rapid for the 15.1-kg carcass than for the 8.4-kg carcass. Internal temperatures of the 8.4-kg carcass were more directly related to external ambient temperatures during the fresh and bloated stages of decomposition. During the decay stage, both carcasses generated internal temperatures significantly above ambient temperatures. Following this stage, internal temperatures fell to approximate ambient temperatures during the postdecay and remains stages. PMID:1750396

  8. An investigation of hydrogen-peroxide reduction and decomposition catalysts

    Microsoft Academic Search

    A. G. Kicheev; S. B. Kalmykova; Yu. A. Kvashnin; G. N. Maksimov; V. N. Saveleva

    1986-01-01

    Silver and platinum metals are known as active catalysts for hydrogen peroxide reduction and decomposition. But their relative activities are not well known, and data are also lacking with respect to the relative rates of reduction and decomposition of HâOâ at different catalysts. It was the aim of this work to study the rates of HâOâ reduction and decomposition at

  9. The existence of Bogomolny decompositions for gauged baby Skyrme models

    E-print Network

    The existence of Bogomolny decompositions for gauged baby Skyrme models L. T. St¸epie´n Abstract The Bogomolny decompositions (Bogomolny equations) for the gauged baby Skyrme models: restricted and full one equations, Bogomol'nyi equations, Bogomolny decomposition, baby Skyrme model 1 Introduction The baby Skyrme

  10. MATROID BASE POLYTOPE DECOMPOSITION II : SEQUENCES OF HYPERPLANE SPLITS

    E-print Network

    Paris-Sud XI, Université de

    MATROID BASE POLYTOPE DECOMPOSITION II : SEQUENCES OF HYPERPLANE SPLITS VANESSA CHATELAIN AND JORGE(2011), 158- 172] about matroid base polytope decomposition. We will present sufficient conditions on a matroid M so its base polytope P(M) has a sequence of hyperplane splits. These yields to decompositions

  11. MULTIRESOLUTION DECOMPOSITION BASED DATA COMPRESSION WITH B-SPLINES

    E-print Network

    Gabbouj, Moncef

    MULTIRESOLUTION DECOMPOSITION BASED DATA COMPRESSION WITH B-SPLINES Rusen Oktem1 , Moncef Gabbouj2email: rusen@cs.tut.#12; 2 email: moncef@cs.tut.#12; ABSTRACT A new multiresolution decomposition scheme bit rate compres- sion. 1. INTRODUCTION Multiresolution decomposition refers to analyzing an image

  12. Lagrangean Decomposition Algorithm for Supply Chain Redesign of Electric Motors

    E-print Network

    Grossmann, Ignacio E.

    Lagrangean Decomposition Algorithm for Supply Chain Redesign of Electric Motors Industry Yongheng Redesign of Electric Motors Industry Introduction of the Supply Chain Model 3/22/13 2 Analia Rodriguez #12 Decomposition Algorithm for Supply Chain Redesign of Electric Motors Industry #12;Lagrangean Decomposition

  13. On the Rate of Decomposition of Diffusion Pump Oil

    Microsoft Academic Search

    Chikara Hayashi

    1954-01-01

    The rate of decomposition of diffusion pump oil under the working condition seems to be an important quantity in reference to the vacuum. The following experiment was carried out to give an answer to the problems, ``Whether various metals really catalyse the decomposition of diffusion pump oil ? and ``Will the gaseous components of the decomposition products limit the ultimate

  14. Decomposition of amino diazeniumdiolates (NONOates): Molecular mechanisms

    DOE PAGESBeta

    Shaikh, Nizamuddin [Brookhaven National Laboratory, Chemistry Dept, Upton, NY (United States); Valiev, Marat [Pacific Northwest National Laboratory, William R. Wiley Environmental Molecular Sciences Laboratory, Richland, WA (United States); Lymar, Sergei V. [Brookhaven National Laboratory, Chemistry Dept, Upton, NY (United States)

    2014-12-01

    Although diazeniumdiolates (X[N(O)NO]?) are extensively used in biochemical, physiological, and pharmacological studies due to their ability to release NO and/or its congeneric nitroxyl, the mechanisms of these processes remain obscure. In this work, we used a combination of spectroscopic, kinetic, and computational techniques to arrive at a quantitatively consistent molecular mechanism for decomposition of amino diazeniumdiolates (amino NONOates: R2N[N(O)NO]?, where R = single bondN(C2H5)2 (1), single bondN(C3H4NH2)2 (2), or single bondN(C2H4NH2)2 (3)). Decomposition of these NONOates is triggered by protonation of their [NN(O)NO]? group with the apparent pKa and decomposition rate constants of 4.6 and 1 s? 1 for 1; 3.5 and 0.083 s? 1 for 2; and 3.8 and 0.0033 s? 1 for 3. Although protonation occurs mainly on the O atoms of the functional group, only the minor R2N(H)N(O)NO tautomer (population ~ 10? 7, for 1) undergoes the Nsingle bondN heterolytic bond cleavage (kd ~ 107 s? 1 for 1) leading to amine and NO. Decompositions of protonated amino NONOates are strongly temperature-dependent; activation enthalpies are 20.4 and 19.4 kcal/mol for 1 and 2, respectively, which includes contributions from both the tautomerization and bond cleavage. The bond cleavage rates exhibit exceptional sensitivity to the nature of R substituents which strongly modulate activation entropy. At pH < 2, decompositions of all three NONOates that have been investigated are subject to additional acid catalysis that occurs through di-protonation of the [NN(O)NO]? group.

  15. The rate of pyrite decomposition on the surface of Venus

    NASA Astrophysics Data System (ADS)

    Fegley, B., Jr.; Lodders, K.; Treiman, A. H.; Klingelhoefer, G.

    1995-05-01

    We report the results of a detailed experiment study of the kinetics and mechanism of pyrite (FeS2) chemical weathering under Venus surface conditions. Pyrite is thermodynamically unstable on the surface of Venus and will spontaneously decompose to pyrrhotite (Fe7S8) because the observed S2 partial pressure in the lower atmosphere of Venus is lower than the S2 vapor pressure over coexisting pyrite and pyrrhotite. Pyrite decomposition kinetics were studied in pure CO2 and CO2 gas mixtures along five isotherms in the temperature range 390-531 C. In all gas mixtures studied, pyrite thermally decomposes to pyrrhotite (Fe7S8), which on continued heating loses sulfur to form more Fe-rich pyrrhotites. During this process the pyrrhotites are also being oxidized to form magnetite (Fe3O4), which converts to maghemite (gamma-Fe2O3), and then to hematite (alpha-Fe2O3). The reaction rates for pyrite thermal decomposition to pyrrhotite were determined by measuring the weight loss. The thickness of the unreacted pyrite in the samples provided a second independent reaction rate measurement. Finally, Mossbauer spectra done on 42 of the 115 experimental samples provided a third set of independent reaction rate data. Pyrite decomposition follows zero-order kinetics and is independent of the amount of pyrite present. The rate of pyrite decomposition is apparently independent of the gas compositions used and of the CO2 number density over a range of a factor of 40. The derived activation energy of approximately 150 kJ/mole is the same in pure CO2, two different CO-CO2 mixtures, and a ternary CO-SO2-CO2 mixture. Based on data for a CO-CO2-SO2 gas mixture with a CO number density approximately 10 times higher than at the surface of Venus and a SO2 number density approximately equal to that at the surface of Venus, the rate of pyrite destruction on the surface of Venus varies from about 1225 +/- 238 days/cm at the top of Maxwell Montes (approximately 660 K) to about 233 +/- 133 days/cm in the plains of Venus (approximately 740 K). These lifetimes are very short on a geological time scale and show that pyrite cannot exist on the surface of Venus for any appreciable length of time.

  16. Influence of litter chemistry and stoichiometry on glucan depolymerization during decomposition of beech (Fagus sylvatica L.) litter

    PubMed Central

    Leitner, Sonja; Wanek, Wolfgang; Wild, Birgit; Haemmerle, Ieda; Kohl, Lukas; Keiblinger, Katharina M.; Zechmeister-Boltenstern, Sophie; Richter, Andreas

    2012-01-01

    Glucans like cellulose and starch are a major source of carbon for decomposer food webs, especially during early- and intermediate-stages of decomposition. Litter quality has previously been suggested to notably influence decomposition processes as it determines the decomposability of organic material and the nutrient availability to the decomposer community. To study the impact of chemical and elemental composition of resources on glucan decomposition, a laboratory experiment was carried out using beech (Fagus sylvatica, L.) litter from four different locations in Austria, differing in composition (concentration of starch, cellulose and acid unhydrolyzable residue or AUR fraction) and elemental stoichiometry (C:N:P ratio). Leaf litter was incubated in mesocosms for six months in the laboratory under controlled conditions. To investigate the process of glucan decomposition and its controls, we developed an isotope pool dilution (IPD) assay using 13C-glucose to label the pool of free glucose in the litter, and subsequently measured the dilution of label over time. This enabled us to calculate gross rates of glucose production through glucan depolymerization, and glucose consumption by the microbial community. In addition, potential activities of extracellular cellulases and ligninases (peroxidases and phenoloxidases) were measured to identify effects of resource chemistry and stoichiometry on microbial enzyme production. Gross rates of glucan depolymerization and glucose consumption were highly correlated, indicating that both processes are co-regulated and intrinsically linked by the microbial demand for C and energy and thereby to resource allocation to enzymes that depolymerize glucans. At early stages of decomposition, glucan depolymerization rates were correlated with starch content, indicating that starch was the primary source for glucose. With progressing litter decomposition, the correlation with starch diminished and glucan depolymerization rates were highly correlated to cellulase activities, suggesting that cellulose was the primary substrate for glucan depolymerization at this stage of decomposition. Litter stoichiometry did not affect glucan depolymerization or glucose consumption rates early in decomposition. At later stages, however, we found significant negative relationships between glucan depolymerization and litter C:N and AUR:N ratio and a positive relationship between glucan depolymerization and litter N concentration. Litter C:N and C:P ratios were negatively related to cellulase, peroxidase and phenoloxidase activities three and six months after incubation, further corroborating the importance of resource stoichiometry for glucan depolymerization after the initial pulse of starch degradation. PMID:22761539

  17. Multicomponent Decompositions for a Sample of S0 galaxies

    E-print Network

    Eija Laurikainen; Heikki Salo; Ronald Buta

    2005-08-03

    We have estimated the bulge-to-total ($B/T$) light ratios in the $K_s$-band for a sample of 24 S0, S0/a and Sa galaxies by applying a 2-dimensional multicomponent decomposition method. For the disk an exponential function is used, the bulges are fitted by a S\\'ersic's $R^{1/n}$ function and the bars and ovals are described either by a S\\'ersic or a Ferrers function. In order to avoid non-physical solutions, preliminary characterization of the structural components is made by inspecting the radial profiles of the orientation parameters and the low azimuthal wavenumber Fourier amplitudes and phases. In order to identify also the inner structures, unsharp masks were created: previously undetected inner spiral arms were found in NGC 1415 and marginally in NGC 3941. Most importantly, we found that S0s have a mean $_K$-ratio of 0.24 $\\pm$ 0.11, which is significantly smaller than the mean $_R$ = 0.6 generally reported in the literature. Also, the surface brightness profiles of the bulges in S0s were found to be more exponential-like than generally assumed, the mean shape parameter of the bulge being $$ = 2.1 $\\pm$ 0.7. We did not find examples of barred S0s lacking the disk component, but we found some galaxies (NGC 718, NGC 1452, NGC 4608) having a non-exponential disk in the bar region. To our knowledge our study is the first attempt to apply a multicomponent decomposition method for a moderately sized sample of early-type disk galaxies

  18. Understanding litter decomposition in drylands: Is litter abrasion an important abiotic factor?

    NASA Astrophysics Data System (ADS)

    Peterson, M.; Bravo-Garza, M. R.; Throop, H. L.; Duarte, L. C.

    2012-12-01

    Drylands comprise approximately 40% of global land cover and about 20% of global soil organic carbon (C) pool. Changes in dryland ecosystem processes, such as litter decomposition, could greatly influence global C cycling and climate change. Current models underestimate rates of litter decomposition in drylands, and little is known about the role and interactions of abiotic drivers in these systems. Research suggests leaf abrasion may play an important role on litter decomposition in drylands by increasing microbial activity or leaching. The Scrape Site at Jornada LTER was stripped of vegetation in 1991, leaving exposed soil that could serve as a source of sand particles to promote leaf abrasion on mesquite shrubs located downwind. This project examines the role that leaf abrasion, promoted in the field by wind erosion, and induced through laboratory simulations, will play in litter decomposition. We hypothesize that leaf abrasion will increase rates of litter decomposition due to facilitation of microbial colonization. Mesquite leaves were collected from two locations: down-wind from the Scrape Site and 80 meters away representing "field abraded" and "unabraded" treatments, respectively. For a "lab abraded" treatment, abrasion was performed by shaking leaves for 30 seconds with sand particles to simulate microscopic characteristics seen in "field abraded" treatment; this treatment resulted in an average leaf area loss of 3.267 %. Differences in decomposition rates among litter treatments were evaluated in a 16 week laboratory incubation. Litter was incubated at 22°C in airtight glass jars containing 50 g of soil (0.053 g water g-1 soil). Rapid colonization by fungi was apparent across treatments, but lab abraded litter showed the most abundant growth. Consequently, lab abraded litter treatment showed 20% and 30% times more accumulation of CO2 -C than field (P= 0.0008) and unabraded (P< 0.0001) litter treatments during the first 6 days of incubation. These results agree with a significant higher mass loss of lab abraded litter after one week of incubation, 4.6% and 4.8% higher than field abraded (P= 0.0005) and unabraded (P= 0.0004) litter, respectively. Results from litter mass loss showed an exponential decrease in all treatments during the first 4 weeks of incubation, where abraded treatments had higher decomposition decay constants than the unabraded leaves: 0.187, 0.170, and 0.164 for the lab abraded, field abraded and unabraded treatments, respectively. Interestingly, differences in the process of litter decomposition among treatments were pronounced during the first weeks of incubation and disappeared by the end of the incubation period where a similar rate of litter mineralization and a ca. 50% mass loss was reported by all litter treatments. Our results suggest that abrasion of leaf litter enhances early stages of decomposition perhaps by creating an exposed outer tissue suitable for microbial colonization. This is reflected by a higher initial accumulation of CO2-C and losses of litter mass in lab abraded litter. Influence of abrasion in litter decomposition was more evident on lab abraded leaves perhaps due to the faster and easier microbial colonization of recently abraded surfaces. Work is in progress to evaluate the amount of C transferred to the soil and the implications of our results on longer-term decomposition.

  19. Resolving the AGN and host emission in the mid-infrared using a model-independent spectral decomposition

    E-print Network

    Hernán-Caballero, Antonio; Hatziminaoglou, Evanthia; Spoon, Henrik W W; Almeida, Cristina Ramos; Santos, Tanio Díaz; Hönig, Sebastian F; González-Martín, Omaira; Esquej, Pilar

    2015-01-01

    We present results on the spectral decomposition of 118 Spitzer Infrared Spectrograph (IRS) spectra from local active galactic nuclei (AGN) using a large set of Spitzer/IRS spectra as templates. The templates are themselves IRS spectra from extreme cases where a single physical component (stellar, interstellar, or AGN) completely dominates the integrated mid-infrared emission. We show that a linear combination of one template for each physical component reproduces the observed IRS spectra of AGN hosts with unprecedented fidelity for a template fitting method, with no need to model extinction separately. We use full probability distribution functions to estimate expectation values and uncertainties for observables, and find that the decomposition results are robust against degeneracies. Furthermore, we compare the AGN spectra derived from the spectral decomposition with sub-arcsecond resolution nuclear photometry and spectroscopy from ground-based observations. We find that the AGN component derived from the d...

  20. Gamma-ray decomposition of PCBs

    SciTech Connect

    Mincher, B.J.; Meikrantz, D.H.; Arbon, R.E.; Murphy, R.J.

    1991-01-01

    This program is the Idaho National Engineering Laboratory (INEL) component of a joint collaborative effort with Lawrence Livermore National Laboratory (LLNL). The purpose of this effort is to demonstrate a viable process for breaking down hazardous halogenated organic wastes to simpler, non-hazardous wastes using high energy ionizing radiation. The INEL effort focuses on the use of spent reactor fuel gamma radiation sources to decompose complex wastes such as PCBs. At LLNL, halogenated solvents such as carbon tetrachloride and trichloroethylene are being studied using accelerator radiation sources. The INEL irradiation experiments concentrated on a single PCB congener so that a limited set of decomposition reactions could be studied. The congener 2, 2{prime}, 3, 3{prime}, 4, 5{prime}, 6, 6{prime}-octachlorobiphenyl was examined following exposure to various gamma doses at the Advanced Test Reactor (ATR) spent fuel pool. The decomposition rates and products in several solvents. are discussed. 7 refs., 13 figs., 1 tab.

  1. Gamma-ray decomposition of PCBs

    SciTech Connect

    Mincher, B.J.; Meikrantz, D.H.; Arbon, R.E.; Murphy, R.J.

    1991-12-01

    This program is the Idaho National Engineering Laboratory (INEL) component of a joint collaborative effort with Lawrence Livermore National Laboratory (LLNL). The purpose of this effort is to demonstrate a viable process for breaking down hazardous halogenated organic wastes to simpler, non-hazardous wastes using high energy ionizing radiation. The INEL effort focuses on the use of spent reactor fuel gamma radiation sources to decompose complex wastes such as PCBs. At LLNL, halogenated solvents such as carbon tetrachloride and trichloroethylene are being studied using accelerator radiation sources. The INEL irradiation experiments concentrated on a single PCB congener so that a limited set of decomposition reactions could be studied. The congener 2, 2{prime}, 3, 3{prime}, 4, 5{prime}, 6, 6{prime}-octachlorobiphenyl was examined following exposure to various gamma doses at the Advanced Test Reactor (ATR) spent fuel pool. The decomposition rates and products in several solvents. are discussed. 7 refs., 13 figs., 1 tab.

  2. Decomposition and unitarity in quantum cosmology

    E-print Network

    Franz Embacher

    1996-12-20

    Considering quantum cosmological minisuperspace models with positive potential, we present evidence that (i) despite common belief there are perspectives for defining a unique, naturally preferred decomposition of the space H of wave functions into two subspaces H^\\pm that generalizes the concept of positive and negative frequency, and that (ii) an underlying unitary evolution within these two subspaces exists and may be described in analogy to the representation of a geometric object in local coordinates: it is associated with the choice of a congruence of classical trajectories endowed with a suitable weight (such a setting is called WKB-branch). The transformation properties of various quantities under a variation of the WKB-branch provide the tool for defining the decomposition. The construction leads to formal series whose actual convergence seems to require additional conditions on the model (related to global geometric issues and possibly to analyticity). It is speculated that this approach might relate to the refined algebraic quantization program.

  3. Heuristic decomposition for non-hierarchic systems

    NASA Technical Reports Server (NTRS)

    Bloebaum, Christina L.; Hajela, P.

    1991-01-01

    Design and optimization is substantially more complex in multidisciplinary and large-scale engineering applications due to the existing inherently coupled interactions. The paper introduces a quasi-procedural methodology for multidisciplinary optimization that is applicable for nonhierarchic systems. The necessary decision-making support for the design process is provided by means of an embedded expert systems capability. The method employs a decomposition approach whose modularity allows for implementation of specialized methods for analysis and optimization within disciplines.

  4. Thermal decomposition of transition metal dithiocarbamates

    Microsoft Academic Search

    S. Singhal; A. N. Garg; K. Chandra

    2004-01-01

    Transition metal dithiocarbamate complexes, [M(S2CN(C2H5)(CH2CH2OH)] (M=Co, Ni, Cu, Zn and Cd) have been prepared and characterized by elemental analysis and infrared spectra. Thermal decomposition of all the complexes occurs in two or three stages. The first stage in all the complexes is always fast with 65–70% mass loss. In all cases the end product is metal oxide except in the

  5. Preparation and Thermal Decomposition of Synthetic Bayerite

    Microsoft Academic Search

    N. Koga; T. Fukagawa; H. Tanaka

    2001-01-01

    The formation process of bayerite, from an aqueous solution of sodium aluminate through enforced decomposition of aluminate\\u000a ions by introducing CO2 gas and aging with mechanical stirring, was investigated by pH measurements of the mother solution during preparation reaction\\u000a and characterization of precipitates obtained at various stages of preparation. An amorphous precipitate, produced initially\\u000a by the reaction of introduced CO2,

  6. Decomposition of amino diazeniumdiolates (NONOates): Molecular mechanisms

    DOE PAGESBeta

    Shaikh, Nizamuddin; Valiev, Marat; Lymar, Sergei V.

    2014-12-01

    Although diazeniumdiolates (X[N(O)NO]?) are extensively used in biochemical, physiological, and pharmacological studies due to their ability to release NO and/or its congeneric nitroxyl, the mechanisms of these processes remain obscure. In this work, we used a combination of spectroscopic, kinetic, and computational techniques to arrive at a quantitatively consistent molecular mechanism for decomposition of amino diazeniumdiolates (amino NONOates: R2N[N(O)NO]?, where R = single bondN(C2H5)2 (1), single bondN(C3H4NH2)2 (2), or single bondN(C2H4NH2)2 (3)). Decomposition of these NONOates is triggered by protonation of their [NN(O)NO]? group with the apparent pKa and decomposition rate constants of 4.6 and 1 s? 1 for 1;more »3.5 and 0.083 s? 1 for 2; and 3.8 and 0.0033 s? 1 for 3. Although protonation occurs mainly on the O atoms of the functional group, only the minor R2N(H)N(O)NO tautomer (population ~ 10? 7, for 1) undergoes the Nsingle bondN heterolytic bond cleavage (kd ~ 107 s? 1 for 1) leading to amine and NO. Decompositions of protonated amino NONOates are strongly temperature-dependent; activation enthalpies are 20.4 and 19.4 kcal/mol for 1 and 2, respectively, which includes contributions from both the tautomerization and bond cleavage. The bond cleavage rates exhibit exceptional sensitivity to the nature of R substituents which strongly modulate activation entropy. At pH « less

  7. Low Temperature Urea Decomposition and SCR Performance

    Microsoft Academic Search

    C. Scott Sluder; John M. E. Storey; Samuel A. Lewis; Linda A. Lewis

    Urea-SCR systems are potentially a highly-effective means of NOX reduction for light-duty diesel vehicles. However, use of urea-SCR technologies at low temperatures presents unique technical challenges. This study was undertaken to provide more knowledge about low temperature urea decomposition and the resulting effects on SCR performance. Data are presented for experiments using two SCR catalysts of differing size with a

  8. New evidence favoring multilevel decomposition and optimization

    NASA Technical Reports Server (NTRS)

    Padula, Sharon L.; Polignone, Debra A.

    1990-01-01

    A new multilevel optimization technique based on a global sensitivity matrix which uses behavior variables in addition to design variables and constraints to decompose the problem is proposed. The technique simplifies the decomposition of the design problem and the programming task and improves the convergence speed of multilevel optimization compared to conventional optimization. The technique is particularly well suited to problems with large numbers of design variables and with computationally expensive constraints.

  9. The eigenscrew decomposition of spatial stiffness matrices

    Microsoft Academic Search

    Shuguang Huang; Joseph M. Schimmels

    2000-01-01

    A manipulator system is modeled as a kinematically unconstrained rigid body suspended by elastic devices. The structure of spatial stiffness is investigated by evaluating the stiffness matrix “primitives”-the rank-1 matrices that compose a spatial stiffness matrix. Although the decomposition of a rank-2 or higher stiffness matrix into the sum of rank-1 matrices is not unique, one property of the set

  10. Thermal Decomposition Models for High Explosive Compositions

    Microsoft Academic Search

    J. M. Zucker; A. J. Barra; D. K. Zerkle; M. J. Kaneshige; P. M. Dickson

    2006-01-01

    As interest in the cook-off response of high explosives expands to include commercially-available compositions, the need has arisen for a broad spectrum of predictive capabilities to describe the untoward thermal decomposition of these explosives. Empirical models for several compositions, including PETN, Semtex and Comp B, have been developed and tested against existing experimental data. Models for Semtex 1A and RDX

  11. Preconditioning via asymptotically-defined domain decomposition

    SciTech Connect

    Ashby, S.F. [Lawrence Livermore National Lab., CA (United States); Kelley, C.T.; Scroggs, J.S. [North Carolina State Univ., Raleigh, NC (United States); Saylor, P.E. [Univ. of Illinois, Urbana, IL (United States). Dept. of Computer Science

    1994-06-01

    Asymptotic analysis is used to derive preconditioners based on operator splitting and domain decomposition for the numerical solution of the advection-diffusion equation. Specifically, asymptotics is used to identify subdomains in which the solution is dominated by a certain operator, and this information is used to construct an effective preconditioner. The authors analyze the one-dimensional case in a function space setting and present numerical results for both one and two dimensions.

  12. Texture decomposition with particle swarm optimization method

    Microsoft Academic Search

    Jian-Guo Tang; Xin-Mingm Zhang; Yun-Lai Deng; Yu-Xuan Du; Zhi-Yong Chen

    2006-01-01

    The newly developed optimization algorithm-particle swarm optimization (PSO) algorithm is introduced into the crystallographic texture decomposition. With the linear correlation factor as the evaluation parameter, both the PSO algorithm and the Nelder–Mead Simplex (NMS) algorithm are evaluated in this paper. The evaluation result reveals that the PSO algorithm is more effective when it comes to the complicated multi-component textures, i.e.,

  13. On the convergence of Adomian decomposition method

    Microsoft Academic Search

    Mohammad Mahdi Hosseini; H. Nasabzadeh

    2006-01-01

    Here, a simple method to determine the rate of convergence of Adomian decomposition method is introduced. The proposed method is used to compare between the rate of convergence of standard and modified (proposed by Wazwaz [A.M. Wazwaz, A new method for solving singular initial value problems in the second-order ordinary differential equations, Appl. Math. Comput. 128 (2002) 45–57]) Adomian methods

  14. SIMPLEX DECOMPOSITIONS FOR REAL-VALUED DATASETS

    Microsoft Academic Search

    Madhusudana Shashanka

    2009-01-01

    In this paper, we introduce the concept of Simplex Decomposi- tions and present a new Semi-Nonnegative decomposition tech- nique that works with real-valued datasets. The motivation stems from the limitations of topic models such as Probabilistic Latent Semantic Analysis (PLSA), that have found wide use in the anal- ysis of non-negative data apart from text corpora such as images, audio

  15. Density functional theory study of the role of anions on the oxidative decomposition reaction of propylene carbonate.

    PubMed

    Xing, Lidan; Borodin, Oleg; Smith, Grant D; Li, Weishan

    2011-12-01

    The oxidative decomposition mechanism of the lithium battery electrolyte solvent propylene carbonate (PC) with and without PF(6)(-) and ClO(4)(-) anions has been investigated using the density functional theory at the B3LYP/6-311++G(d) level. Calculations were performed in the gas phase (dielectric constant ? = 1) and employing the polarized continuum model with a dielectric constant ? = 20.5 to implicitly account for solvent effects. It has been found that the presence of PF(6)(-) and ClO(4)(-) anions significantly reduces PC oxidation stability, stabilizes the PC-anion oxidation decomposition products, and changes the order of the oxidation decomposition paths. The primary oxidative decomposition products of PC-PF(6)(-) and PC-ClO(4)(-) were CO(2) and acetone radical. Formation of HF and PF(5) was observed upon the initial step of PC-PF(6)(-) oxidation while HClO(4) formed during initial oxidation of PC-ClO(4)(-). The products from the less likely reaction paths included propanal, a polymer with fluorine and fluoro-alkanols for PC-PF(6)(-) decomposition, while acetic acid, carboxylic acid anhydrides, and Cl(-) were found among the decomposition products of PC-ClO(4)(-). The decomposition pathways with the lowest barrier for the oxidized PC-PF(6)(-) and PC-ClO(4)(-) complexes did not result in the incorporation of the fluorine from PF(6)(-) or ClO(4)(-) into the most probable reaction products despite anions and HF being involved in the decomposition mechanism; however, the pathway with the second lowest barrier for the PC-PF(6)(-) oxidative ring-opening resulted in a formation of fluoro-organic compounds, suggesting that these toxic compounds could form at elevated temperatures under oxidizing conditions. PMID:22004044

  16. Autocatalytic Decomposition at Shear-Strain Interfaces

    NASA Astrophysics Data System (ADS)

    Kuklja, M. M.; Rashkeev, Sergey N.

    2009-12-01

    Atomic scale mechanisms of the initiation of chemical processes in energetic molecular crystals leading to the decomposition and ultimately to an explosive chain reaction, are far from being completely understood. We investigated the onset of the initiation processes in two energetic crystals—diamino-dinitroethylene (DADNE, C2H4N4O4) and triamino-trinitrobenzene (TATB, C6H6N6O6). We suggest that an autocatalytic decomposition mechanism is likely to take place in DADNE crystal that is built out of corrugated, dashboard-shaped molecular layers, and the level of the induced shear-strain perturbation between the layers strongly depends upon the presence of interstitial NO2 groups. Unlike this, in TATB, which consists of flat, graphite-like molecular layers, an interstitial NO2 group positioned between two layers produces a local molecular orientation disorder and barely affects the C-NO2 decomposition barrier. Split off NO2 groups in the interstitial exhibit a series of exothermic reactions. In DADNE, these reactions start at a lower concentration of interstitial nitro-groups which may be correlated to the higher sensitivity of this material to the initiation as compared to TATB.

  17. Perspectives on Pentaerythritol Tetranitrate (PETN) Decomposition

    SciTech Connect

    Chambers, D; Brackett, C; Sparkman, D O

    2002-07-01

    This report evaluates the large body of work involving the decomposition of PETN and identifies the major decomposition routes and byproducts. From these studies it becomes apparent that the PETN decomposition mechanisms and the resulting byproducts are primarily determined by the chemical environment. In the absence of water, PETN can decompose through the scission of the O-NO{sup 2} bond resulting in the formation of an alkoxy radical and NO{sub 2}. Because of the relatively high reactivity of both these initial byproducts, they are believed to drive a number of autocatalytic reactions eventually forming (NO{sub 2}OCH{sub 2}){sub 3}CCHO, (NO{sub 2}OCH{sub 2}){sub 2}C=CHONO{sub 2}, NO{sub 2}OCH=C=CHONO{sub 2}, (NO{sub 2}OCH{sub 2}){sub 3}C-NO{sub 2}, (NO{sub 2}OCH{sub 2}){sub 2}C(NO{sub 2}){sub 2}, NO{sub 2}OCH{sub 2}C(NO{sub 2}){sub 3}, and C(NO{sub 2}){sub 4} as well as polymer-like species such as di-PEHN and tri-PEON. Surprisingly, the products of many of these proposed autocatalytic reactions have never been analytically validated. Conversely, in the presence of water, PETN has been shown to decompose primarily to mono, di, and tri nitrates of pentaerythritol.

  18. Structure of positive decompositions of exponential operators.

    PubMed

    Chin, Siu A

    2005-01-01

    The solution of many physical evolution equations can be expressed as an exponential of two or more operators acting on initial data. Accurate solutions can be systematically derived by decomposing the exponential in a product form. For time-reversible equations, such as the Hamilton or the Schrödinger equation, it is immaterial whether or not the decomposition coefficients are positive. In fact, most symplectic algorithms for solving classical dynamics contain some negative coefficients. For time-irreversible systems, such as the Fokker-Planck equation or the quantum statistical propagator, only positive-coefficient decompositions, which respect the time-irreversibility of the diffusion kernel, can yield practical algorithms. These positive time steps only, forward decompositions, are a highly effective class of factorization algorithms. This work presents a framework for understanding the structure of these algorithms. By a suitable representation of the factorization coefficients, we show that specific error terms and order conditions can be solved analytically. Using this framework, we can go beyond the Sheng-Suzuki theorem and derive a lower bound for the error coefficient e(VTV). By generalizing the framework perturbatively, we can further prove that it is not possible to have a sixth-order forward algorithm by including only the commutator [VTV] tripple bond [V, [T,V

  19. Phosphorus transformations during decomposition of wetland macrophytes.

    PubMed

    Cheesman, Alexander W; Turner, Benjamin L; Inglett, Patrick W; Reddy, K Ramesh

    2010-12-15

    The microbially mediated transformation of detrital P entering wetlands has important implications for the cycling and long-term sequestration of P in wetland soils. We investigated changes in P forms in sawgrass (Cladium jamaicense Crantz) and cattail (Typha domingensis Pers.) leaf litter during 15 months of decomposition at two sites of markedly different nutrient status within a hard-water subtropical wetland (Water Conservation Area 2A, Florida). Leaf litter decomposition at the nutrient enriched site resulted in net sequestration of P from the environment in forms characteristic of microbial cells (i.e., phosphodiesters and pyrophosphate). In contrast, low P concentrations at the unenriched site resulted in little or no net sequestration of P, with changes in P forms limited to the loss of compounds present in the initial leaf litter. We conclude that under nutrient-rich conditions, P sequestration occurs through the accumulation of microbially derived compounds and the presumed concentration of endogenous macrophyte P. Under nutrient-poor conditions, standing P pools within wetland soils appear to be independent of the heterotrophic decomposition of macrophyte leaf litter. These conclusions have important implications for our ability to predict the nature, stability, and rates of P sequestration in wetlands in response to changes in nutrient loading. PMID:21090603

  20. Faster Algorithms on Branch and Clique Decompositions

    NASA Astrophysics Data System (ADS)

    Bodlaender, Hans L.; van Leeuwen, Erik Jan; van Rooij, Johan M. M.; Vatshelle, Martin

    We combine two techniques recently introduced to obtain faster dynamic programming algorithms for optimization problems on graph decompositions. The unification of generalized fast subset convolution and fast matrix multiplication yields significant improvements to the running time of previous algorithms for several optimization problems. As an example, we give an O^{*}(3^{?/2k}) time algorithm for Minimum Dominating Set on graphs of branchwidth k, improving on the previous O *(4 k ) algorithm. Here ? is the exponent in the running time of the best matrix multiplication algorithm (currently ?< 2.376). For graphs of cliquewidth k, we improve from O *(8 k ) to O *(4 k ). We also obtain an algorithm for counting the number of perfect matchings of a graph, given a branch decomposition of width k, that runs in time O^{*}(2^{?/2k}). Generalizing these approaches, we obtain faster algorithms for all so-called [?,?]-domination problems on branch decompositions if ? and ? are finite or cofinite. The algorithms presented in this paper either attain or are very close to natural lower bounds for these problems.