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1

Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography  

ERIC Educational Resources Information Center

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…

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

2011-01-01

2

Density dependence of isospin observables in spinodal decomposition  

SciTech Connect

Isotopic fluctuations in fragment formation are investigated in a quasianalytical description of the spinodal decomposition scenario. By exploiting the fluctuation-dissipation relations the covariance matrix of density fluctuations is derived as a function of the wave vector k for nuclear matter at given values of density, charge asymmetry, temperature, and the time that the system spends in the instability region. Then density fluctuations in ordinary space are implemented with a Fourier transform performed in a finite cubic lattice. Inside this box, domains with different density coexist, from which clusters of nucleons eventually emerge. Within our approach, the isotopic distributions are determined by the N/Z ratio of the leading unstable isoscalar-like modes and by isovector-like fluctuations present in the matter undergoing the spinodal decomposition. Hence the average value of the N/Z ratio of clusters and the width of the relative distribution reflect the properties of the symmetry energy. By generating a large number of events, these calculations allow a careful investigation of the cluster isotopic content as a function of the cluster density. A uniform decrease of the average charge asymmetry and of the width of the isotopic distributions with increasing density is observed. Finally, we remark that the results essentially refer to the early breakup of the system.

Colonna, M.; Matera, F. [Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy); Dipartimento di Fisica, Universita degli Studi di Firenze and Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, Via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy)

2008-06-15

3

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

ERIC Educational Resources Information Center

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…

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

2013-01-01

4

Young Children's Thinking About Decomposition: Early Modeling Entrees to Complex Ideas in Science  

NASA Astrophysics Data System (ADS)

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 in-class observations of different types of soil and soil profiling, visits to the school's compost bin, structured observations of decaying organic matter of various kinds, study of organisms that live in the soil, and models of environmental conditions that affect rates of decomposition. Both before and after instruction, students completed a written performance assessment that asked them to reason about the process of decomposition. Additional information was gathered through one-on-one interviews with six focus students who represented variability of performance across the class. During instruction, researchers collected video of classroom activity, student science journal entries, and charts and illustrations produced by the teacher. After instruction, the first-grade students showed a more nuanced understanding of the composition and variability of soils, the role of visible organisms in decomposition, and environmental factors that influence rates of decomposition. Through a variety of representational devices, including drawings, narrative records, and physical models, students came to regard decomposition as a process, rather than simply as an end state that does not require explanation.

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

2013-01-01

5

Decomposition  

USGS Publications Warehouse

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.

Middleton, Beth A.

2014-01-01

6

Evidence for Early Morphological Decomposition in Visual Word Recognition  

ERIC Educational Resources Information Center

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…

Solomyak, Olla; Marantz, Alec

2010-01-01

7

Early Pulsar Observations in Australia  

NASA Astrophysics Data System (ADS)

The news about the discovery of the pulsar CP1919 reached Australia soon after the Hewish et al. publication in Nature came out at the end of February 1968. Immediately the Parkes radio telescope was transferred from scheduled observations to observe this new exciting object. Since pulsars have steep spectra, low radio frequency receivers were needed that were not supported by the Radiophysics Division of the CSIRO. As a result I, a staff member of the School of Electrical Engineering, Sydney University, was asked to come with my low-frequency receivers to Parkes and join in the first observations. Later the Molonglo Mills Cross radio telescope showed its suitability to pulsar discoveries and became involved in a number of important discoveries. New additional equipment aimed for the reception of pulsating signals had to be constructed in a hurry. In my talk I will cover the period 1968 to 1970 when I left Sydney for the Max-Planck-Institute in Bonn with its 100-m radio telescope.

Wielebinski, R.

2012-12-01

8

Polar decomposition for attitude determination from vector observations  

NASA Technical Reports Server (NTRS)

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.

Bar-Itzhack, Itzhack Y.

1993-01-01

9

Acousto-spinodal decomposition of compressible polymer solutions: early stage analysis.  

PubMed

The structure and dynamics of early stage kinetics of pressure-induced phase separation of compressible polymer solutions via spinodal decomposition is analyzed using a linear Euler-Cahn-Hilliard model and the modified Sanchez Lacombe equation of state. The integrated density wave and Cahn-Hilliard equations combine the kinetic and structural characteristics of spinodal decomposition with density waves arising from pressure-induced couplings. When mass transfer rate is slower that acoustic waves, concentration gradients generate density waves that cycle back into the spinodal decomposition dynamics, resulting in oscillatory demixing. The wave attenuation increases with increasing mass transfer rates eventually leading to nonoscillatory spinodal demixing. The novel aspects of acousto-spinodal decomposition arise from the coexistence of stable oscillatory density dynamics and the unstable monotonic concentration dynamics. Scaling laws for structure and dynamics indicate deviations from incompressible behavior, with a significant slowing down of demixing due to couplings with density waves. Partial structure factors for density and density-concentration reflect the oscillatory nature of acousto-spinodal modes at lower wave vectors, while the single maximum at a constant wave vector reflects the presence of a dominant mode in the linear regime. The computed total structure factor is in qualitative agreement with experimental data for a similar polymer solution. PMID:21568529

Rasouli, Ghoncheh; Rey, Alejandro D

2011-05-14

10

Using observation to constrain early universe cosmology  

NASA Astrophysics Data System (ADS)

The goal of the contemporary cosmologist must be to search for models of the early universe that satisfy current observational tests and to seek new ways to discriminate between these models. At the base of this endeavor is understanding how gravity and quantum field theory can lead to natural models of the early universe and specifically how these models might emerge from various extensions of the Standard Model. This investigation presents new ways by which observations--of both electromagnetic and gravitational radiation--can identify viable cosmological scenarios. The first of these projects extends the canonical treatment of single field slow-roll inflation to models consisting of multiple fields. This is done by defining a system of multiple-field slow-roll parameters. The evolution of these parameters can be described by a set of flow equations whose truncation, to any finite order, can be solved exactly. Further, I show how these parameters are related to cosmological parameters, namely the scalar spectral index, n s , and the tensor to scalar ratio, t. The second of these projects searches for observational signatures laid down at the end of inflation. As the universe reheats, coherent oscillations of the inflaton field may excite momentum modes of fields to which it is coupled. This process is known as preheating and is an efficient mechanism by which inflationary energy can be converted into matter fields. During this process, large gradient energies should produce gravitational radiation. I develop an algorithm by which this radiation can be calculated and implement its calculation numerically. I show the robustness of this method, and calculate the gravitational wave power spectrum for a number of interesting and useful cases.

Giblin, John T., Jr.

11

SCUBA Observations of Early-Type Galaxies  

NASA Astrophysics Data System (ADS)

We present SCUBA observations of the emission of 23 E and S0 galaxies at wavelengths of 850 and 450 ?m. Four galaxies are detected at 850 ?m with signal-to-noise ratios above 3.0, and an additional galaxy, NGC 6524, is detected at both 850 and 450 ?m. We use the SCUBA data with published optical and IRAS photometry to construct spectral energy distributions (SEDs) of 15 galaxies extending from 0.36 to 850 ?m. Those SEDs are fit by single-temperature dust emission models and by predictions generated by self-consistent Monte Carlo simulations of radiative transfer in three-dimensional distributions of stars and diffuse dust. We discuss implications for the question of cool dust in early-type galaxies, the spatial distribution of diffuse dust, and its ability to generate optical color gradients.

Savoy, Jonathan; Welch, Gary A.; Fich, Michel

2009-11-01

12

SCUBA OBSERVATIONS OF EARLY-TYPE GALAXIES  

SciTech Connect

We present SCUBA observations of the emission of 23 E and S0 galaxies at wavelengths of 850 and 450 mum. Four galaxies are detected at 850 mum with signal-to-noise ratios above 3.0, and an additional galaxy, NGC 6524, is detected at both 850 and 450 mum. We use the SCUBA data with published optical and IRAS photometry to construct spectral energy distributions (SEDs) of 15 galaxies extending from 0.36 to 850 mum. Those SEDs are fit by single-temperature dust emission models and by predictions generated by self-consistent Monte Carlo simulations of radiative transfer in three-dimensional distributions of stars and diffuse dust. We discuss implications for the question of cool dust in early-type galaxies, the spatial distribution of diffuse dust, and its ability to generate optical color gradients.

Savoy, Jonathan; Welch, Gary A. [Saint Mary's University, Department of Astronomy and Physics, Halifax, Nova Scotia B3H 3C3 (Canada); Fich, Michel, E-mail: jsavoy@ap.stmarys.c, E-mail: gwelch@ap.stmarys.c, E-mail: fich@astro.uwaterloo.c [University of Waterloo, Department of Physics and Astronomy, Waterloo, Ontario (Canada)

2009-11-20

13

Histopathologic observations on early oral implant failures.  

PubMed

The purpose of this study was to morphologically describe the tissues surrounding 20 early failed (prior to prosthesis placement) Brånemark System oral implants. The implants and their surrounding tissues were consecutively retrieved and analyzed with light microscopy and transmission electron microscopy. Failures were chronologically divided into those occurring prior to, at, and after abutment connection. The clinical conditions varied from osteomyelitis to totally asymptomatic but mobile implants. Different histopathologic pictures were observed, ranging from a stratified, almost acellular, connective tissue layer, via a capsule with a great number of inflammatory cells, to a heterogeneous interface with areas of highly vascularized connective tissue and portions of poorly mineralized bone detached from the implant surface. The histopathologic variation may reflect different etiologies and/or time stages of the failure process. Epithelial downgrowth was occasionally observed for asymptomatic submerged implants. Epithelial cells were attached to the failed implant surface via hemidesmosomes. The histologic, clinical, and radiographic findings together indicated that 3 major etiologies might have been implicated in the failure processes: impaired healing ability of the host bone site, disruption of a weak bone-to-implant interface after abutment connection, and infection in situations with complicated surgery. PMID:10612916

Esposito, M; Thomsen, P; Ericson, L E; Lekholm, U

1999-01-01

14

Early stages of decomposition in iron-carbon and iron-nitrogen martensites: Diffraction analysis using synchrotron radiation  

SciTech Connect

The early stages of decomposition of iron-carbon and iron-nitrogen martensites were studied by means of diffraction analysis. After aging at room temperature (RT) for 3.5 years and after tempering at 405 K for 1 hour, [var epsilon]/[eta] transition carbide reflections but no [alpha][double prime]-type (superstructure) reflections were detected for FeC martensites. However, for FeN martensites, the [alpha][double prime] superstructure reflections were observed on aging at RT for 3.5 years and on tempering at 405 K for 1.5 hour. For short aging times at RT (up to 60 hours), [alpha][double prime] reflections (not of the superstructure type) were observed for FeN martensites. Upon tempering, changes in the [alpha][double prime] crystal structure occur, which were discussed in terms of annihilation of structural vacancies on the nitrogen sublattice and stress relaxation. In the diffraction pattern recorded from FeC martensite (for short aging times at RT), weak reflections occurred which could not be identified conclusively yet and which disappeared after tempering for 1 hour at 405 K.

Van Genderen, M.J.; Boettger, A.; Mittemeijer, E.J. (Delft Univ. of Technology (Netherlands). Lab. of Metallurgy); Cernik, R.J. (Science and Engineering Research Council Daresbury Lab., Warrington (United Kingdom))

1993-09-01

15

Early Childhood Laboratory Professional Development Visits and Observational Opportunities  

E-print Network

Early Childhood Laboratory Professional Development Visits and Observational Opportunities The SFA Early Childhood Laboratory is a public childcare for Infants through Pre- Kindergarten. We minutes) Materials related to the requested area of focus included Additional professional development

Long, Nicholas

16

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

NASA Astrophysics Data System (ADS)

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.

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

2012-01-01

17

Early Childhood: Learning to Observe Animals.  

ERIC Educational Resources Information Center

Suggests: (1) activities to enhance interest during observations of animals in the elementary science classroom; (2) possible questions to ask during these observations; and (3) sources for observing animals such as pet stores and farms, as well as bringing pets into the classroom. (DS)

McIntyre, Margaret, Ed.

1981-01-01

18

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

SciTech Connect

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.

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

19

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

20

Early Observations of Sunspots: Scheiner and Galileo  

NASA Astrophysics Data System (ADS)

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.

Casanovas, J.

21

The Early Years: Developing Observation Skills  

NSDL National Science Digital Library

We typically know children are learning when they are able to make sense of an object's materials or a situation that was previously a bit mysterious and communicate what they have figured out. But what about observing? One of the process skills listed in

Ashbrook, Peggy

2010-10-01

22

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

NASA Astrophysics Data System (ADS)

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.

Shen, Wen-Bin; Ding, Hao

2014-03-01

23

SOAR remote observing: tactics and early results  

NASA Astrophysics Data System (ADS)

Travel from North America to the 4.1m SOAR telescope atop Cerro Pachon exceeds $1000, and takes >16 hours door to door (20+ hours typically). SOAR aims to exploit best seeing, requiring dynamic scheduling that is impossible to accomplish when catering to peripatetic astronomers. According to technical arguments at www.peakoil.org, we are near the peak rate of depleting world petroleum, so can expect travel costs to climb sharply. With the telecom bubble's glut of optical fiber, we can transmit data more efficiently than astronomers and "observe remotely". With data compression, less than half of the 6 Mbps bandwidth shared currently by SOAR and CTIO is enough to enable a high-fidelity observing presence for SOAR partners in North America, Brazil, and Chile. We discuss access from home by cable modem/DSL link.

Cecil, Gerald N.; Crain, J. Adam

2004-09-01

24

The Early Years: Observing With Magnifiers  

NSDL National Science Digital Library

Inspire your students to become detailed observers by encouraging the use of magnifiers. Magnification can make us see an object with new understanding. Rachel Carson said, "Some of nature's most exquisite handiwork is on a miniature scale, as anyone knows who has applied a magnifying glass to a snowflake" (Carson 1965). The lesson described here uses interesting objects to give children a reason to learn to use a magnifier.

Ashbrook, Peggy

2008-02-01

25

Unimolecular Thermal Decomposition of Phenol and d5-Phenol: Direct Observation of Cyclopentadiene Formation via Cyclohexadienone  

SciTech Connect

The pyrolyses of phenol and d{sub 5}-phenol (C{sub 6}H{sub 5}OH and C{sub 6}D{sub 5}OH) have been studied using a high temperature, microtubular ({mu}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 {mu}tubular reactor of approximately 50-100 {micro}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; C{sub 6}H{sub 5}OH {yields} c-C{sub 6}H{sub 6} = O {yields} c-C{sub 5}H{sub 6} + CO. The cyclopentadiene loses a H atom to generate the cyclopentadienyl radical which further decomposes to acetylene and propargyl radical; c-C{sub 5}H{sub 6} {yields} c-C{sub 5}H{sub 5} + H {yields} HC {triple_bond} CH + HCCCH{sub 2}. 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; C{sub 6}H{sub 5}O-H {yields} C{sub 6}H{sub 5}O + H {yields} c-C{sub 5}H{sub 5} + CO. The direct decarbonylation reaction remains an important channel in the thermal decomposition mechanisms of the dihydroxybenzenes. Both catechol (o-HO-C{sub 6}H{sub 4}-OH) and hydroquinone (p-HO-C{sub 6}H{sub 4}-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.

Scheer, A. M.; Mukarakate, C.; Robichaud, D. J.; Nimlos, M. R.; Carstensen, H. H.; Barney, E. G.

2012-01-28

26

Early fault diagnosis of rotating machinery based on wavelet packets—Empirical mode decomposition feature extraction and neural network  

NASA Astrophysics Data System (ADS)

After analyzing the shortcomings of current feature extraction and fault diagnosis technologies, a new approach based on wavelet packet decomposition (WPD) and empirical mode decomposition (EMD) are combined to extract fault feature frequency and neural network for rotating machinery early fault diagnosis is proposed. Acquisition signals with fault frequency feature are decomposed into a series of narrow bandwidth using WPD method for de-noising, then, the intrinsic mode functions (IMFs), which usually denoted the features of corresponding frequency bandwidth can be obtained by applying EMD method. Thus, the component of IMF with signal feature can be separated from all IMFs and the energy moment of IMFs is proposed as eigenvector to effectively express the failure feature. The classical three layers BP neural network model taking the fault feature frequency as target input of neural network, the 5 spectral bandwidth energy of vibration signal spectrum as characteristic parameter, and the 10 types of representative rotor fault as output can be established to identify the fault pattern of a machine. Lastly, the fault identification model of rotating machinery with rotor lateral early crack based on BP neural network is taken as an example. The results show that the proposed method can effectively get the signal feature to diagnose the occurrence of early fault of rotating machinery.

Bin, G. F.; Gao, J. J.; Li, X. J.; Dhillon, B. S.

2012-02-01

27

Preliminary observations of the decomposition of crown-of-thorns starfish, Acanthaster planci (L.)  

Microsoft Academic Search

The rate of decomposition of 67 crown-of-thorns starfish was monitored over 7–9 days on 2 reefs of the Great Barrier Reef in 7 permanent quadrats in different depths and habitats. The pattern of decomposition was similar in all quadrats irrespective of the site or depth. Many different organisms, including crown-of-thorns starfish, fed on or scavenged the remains. Despite this activity

P. J. Moran

1992-01-01

28

Preliminary observations of the decomposition of crown-of-thorns starfish, Acanthaster planci (L.)  

Microsoft Academic Search

The rate of decomposition of 67 crown-of-thorns starfish was monitored over 7 9 days on 2 reefs of the Great Barrier Reef in 7 permanent quadrats in different depths and habitats. The pattern of decomposition was similar in all quadrats irrespective of the site or depth. Many different organisms, including crown-of-thorns starfish, fed on or scavenged the remains. Despite this

P. J. Moran

1992-01-01

29

ALMA observations during its first early science cycles  

NASA Astrophysics Data System (ADS)

The Atacama Large Millimeter/submillimeter Array (ALMA) is a new interferometer operated on Llano de Chajnantor at 5050 m altitude in the Chilean Andes. It consists of 66 antennas operating in the mm/submm windows between 3 and 0.3 mm wavelength. Early science observations using 16 antennas (known as Cycle 0) started in parallel with construction in September 2011, in order to provide useful results to the astronomy community and to facilitate the ongoing characterization of its system. ALMA is currently in Cycle 2 of early science observations. This presentation describes the development and progress of ALMA observations and data processing from Cycle 0 towards full operations.

Nyman, Lars-Åke; Cox, Pierre; Corder, Stuartt; Saito, Masao; Lundgren, Andreas; Vila-Vilaro, Baltasar; Espada, Daniel; Villard, Eric; Barrios, Emilio; Andreani, Paola; Hibbard, John; Tatematsu, Ken'ichi

2014-08-01

30

Preliminary observations of the decomposition of crown-of-thorns starfish, Acanthaster planci (L.)  

NASA Astrophysics Data System (ADS)

The rate of decomposition of 67 crown-of-thorns starfish was monitored over 7 9 days on 2 reefs of the Great Barrier Reef in 7 permanent quadrats in different depths and habitats. The pattern of decomposition was similar in all quadrats irrespective of the site or depth. Many different organisms, including crown-of-thorns starfish, fed on or scavenged the remains. Despite this activity the remains could be recognised as crown-of-thorns starfish for up to 5 days. The reason for the sudden disappearance of starfish at the ends of outbreaks is briefly discussed.

Moran, P. J.

1992-07-01

31

Observational effects of the early episodically dominating dark energy  

NASA Astrophysics Data System (ADS)

We investigate the observational consequences of the early episodically dominating dark energy on the evolution of cosmological structures. For this aim, we introduce the minimally coupled scalar-field dark energy model with the Albrecht-Skordis potential, which allows a sudden ephemeral domination of a dark energy component during the radiation or early matter era. The conventional cosmological parameters in the presence of such an early dark energy are constrained with WMAP and Planck cosmic microwave background radiation data including other external data sets. It is shown that in the presence of such an early dark energy, the estimated cosmological parameters can deviate substantially from the currently known ? cold dark matter (? CDM )-based parameters, with best-fit values differing by several percent for WMAP and by a percent level for Planck data. For the latter case, only a limited amount of dark energy with episodic nature is allowed since the Planck data strongly favor the ? CDM model. Compared with the conventional dark energy model, the early dark energy dominating near the radiation-matter equality or at the early matter era results in the shorter cosmic age or the presence of tensor-type perturbation, respectively. Our analysis demonstrates that the alternative cosmological parameter estimation is allowed based on the same observations even in Einstein's gravity.

Park, Chan-Gyung; Lee, Jae-heon; Hwang, Jai-chan; Noh, Hyerim

2014-10-01

32

The Debris ISO Key Project: Early Release Observations  

NASA Astrophysics Data System (ADS)

The ISO Dust Debris key project is a collaboration between UCLA and Caltech to study the physical nature and evolutionary history of dust debris clouds around solar mass stars. The sample objects include F and G stars within 20 pc of the Sun, as well as members of nearby open clusters and weak-line T Tauri stars. The 60 and 100 micron observations, made with ISOPHOT, consist of broadband single- element photometry plus far-infrared imaging with a small array. Approximately 15 nearby and cluster stars were released during February 1996 for early observations to assess the performance of ISO. The results of these early release observations, and their effect upon the Debris program, will be discussed. Issues concerning signal-to-noise and calibration will be addressed.

Becklin, E. E.; Silverstone, M.; Zuckerman, B.; Spangler, C.; Sargent, A.; Goldreich, P.; Mannings, V.

1996-05-01

33

Direct observation and quantification of nanoscale spinodal decomposition in super duplex stainless steel weld metals.  

PubMed

Three variants of super duplex stainless steel weld metals with the basic composition 29Cr-8Ni-2Mo (wt%) were investigated. The nitrogen content of the three materials was 0.22%, 0.33% and 0.37%, respectively. Isothermal heat treatments were performed at 450 degrees C for times up to 243 h. The hardness evolution of the three materials was found to vary with the overall concentration of the nitrogen. Atom probe field ion microscopy (APFIM) was used to directly detect and quantify the degree of spinodal decomposition in different material conditions. 3-DAP atomic reconstruction clearly illustrate nanoscale variation of iron rich (alpha) and chromium rich (alpha') phases. A longer ageing time produces a coarser microstructure with larger alpha and alpha' domains. Statistical evaluation of APFIM data showed that phase separation was significant already after 1 h of ageing that gradually became more pronounced. Although nanoscale concentration variation was evident, no significant influence of overall nitrogen content on the degree of spinodal decomposition was found. PMID:19504899

Shariq, Ahmed; Hättestrand, Mats; Nilsson, Jan-Olof; Gregori, Andrea

2009-06-01

34

Intercomparison between observed and simulated variability in global ocean heat content using empirical mode decomposition, part I: modulated annual cycle  

NASA Astrophysics Data System (ADS)

This study proposes a new more precise and detailed method to examine the performance of IPCC AR4 models in simulation of nonlinear variability of global ocean heat content (OHC) on the annual time scale during 1950-1999. The method is based on the intercomparison of modulated annual cycle (MAC) of OHC and its instantaneous frequency (IF), derived by Empirical Mode Decomposition and Hilbert-Huang Transformation. In addition to indicate the general agreement in gross features globally between models and observation, our results point out the problems both in observation and in modeling. In the well observed Northern Hemisphere, models exhibit extremely good skills to capture nonlinear annual variability of OHC. The simulated MACs are highly correlated with observations (>0.95) and the IF of MACs varies coherently with each other. However, in sparsely observed Southern Hemisphere (SH), even though the simulated MACs highly correlate with observations, the IF shows significant difference. This comparisons show that the models exhibit coherent variability of IF of MACs in SH with each other, but not with observations, revealing the problems in the objective analyzed dataset using sparse observations. In the well observed tropic region, the models lack the coherence with the observations, indicating inadequate physics of the models in the tropical area. These results illustrate that the proposed method can be used routinely to identify problems in both models and in observation of the global ocean as a critical component of global climate change.

Chen, Xianyao; Zhang, Yuanling; Zhang, Min; Feng, Ying; Wu, Zhaohua; Qiao, Fangli; Huang, Norden Eh

2013-12-01

35

TEMPORAL SIGNATURES OF AIR QUALITY OBSERVATIONS AND MODEL OUTPUTS: DO TIME SERIES DECOMPOSITION METHODS CAPTURE RELEVANT TIME SCALES?  

EPA Science Inventory

Time series decomposition methods were applied to meteorological and air quality data and their numerical model estimates. Decomposition techniques express a time series as the sum of a small number of independent modes which hypothetically represent identifiable forcings, thereb...

36

Bacterial decomposition of coral mucus as evaluated by long-term and quantitative observation  

NASA Astrophysics Data System (ADS)

Coral mucus released from Acropora formosa and Montipora digitata was incubated with bacteria under dark conditions for 1 year to evaluate the quantitative degradability. All the mucus samples showed a similar decomposition pattern: about 80% of total organic carbon (TOC) in the mucus was mineralized within 1 month, while some mucus was slowly decomposed over the 1 year. Regression analysis using an exponential curve considering three degradability pools (labile, semilabile, and refractory) fitted the changes of the TOC concentrations very well ( r 2 > 0.99). Compiling the data on the two coral species, the labile organic C in the coral mucus had mineralization rates of 10-18% d-1 and accounted for 79-87% of the initial TOC in the mucus. Semilabile organic C had mineralization rates of 0.3-1.6% d-1 and accounted for 11-18% of the initial TOC. Refractory organic C accounted for 6% at most. These results suggest that not all coral mucus is rapidly decomposed by bacteria but some mucus remains as semilabile and refractory organic matter for several months.

Tanaka, Y.; Ogawa, H.; Miyajima, T.

2011-06-01

37

Aminoxyl (nitroxyl) radicals in the early decomposition of the nitramine RDX.  

PubMed

The explosive nitramine RDX (1,3,5-trinitrohexahydro-s-triazine) is thought to decompose largely by homolytic N-N bond cleavage, among other possible initiation reactions. Density-functional theory (DFT) calculations indicate that the resulting secondary aminyl (R2N·) radical can abstract an oxygen atom from NO2 or from a neighboring nitramine molecule, producing an aminoxyl (R2NO·) radical. Persistent aminoxyl radicals have been detected in electron-spin resonance (ESR) experiments and are consistent with autocatalytic "red oils" reported in the experimental literature. When the O-atom donor is a nitramine, a nitrosamine is formed along with the aminoxyl radical. Reactions of aminoxyl radicals can lead readily to the "oxy-s-triazine" product (as the s-triazine N-oxide) observed mass-spectrometrically by Behrens and co-workers. In addition to forming aminoxyl radicals, the initial aminyl radical can catalyze loss of HONO from RDX. PMID:23373538

Irikura, Karl K

2013-03-14

38

A longitudinal observation of early pulmonary responses to cotton dust  

PubMed Central

Aims: To examine early adverse pulmonary effects of exposure to cotton dust, and to identify potential risk factors, including atopy for pulmonary responses to cotton dust. Methods: Spirometry, methacholine challenge testing, and questionnaire; performed among 101 non-smoking newly hired textile workers at baseline (prior to starting work), and at 3, 12, and 18 months after starting work. Concentrations of airborne cotton dust in various work areas were measured at each follow up survey using vertical elutriators. Results: The incidence of non-specific respiratory symptoms was 8% at three months, then diminished afterwards. Substantial acute cross shift drops in FEV1 at each follow up survey, and longitudinal declines in FVC and FEV1 after 12 months of exposure were observed. Airway responsiveness to methacholine increased with follow up time, and was more pronounced among atopics. Increasing airway responsiveness was strongly correlated with cross shift drops in FEV1. In addition, one or more respiratory symptoms at three months was significantly, and pre-existing atopy marginally significantly, associated with cross shift drops in FEV1 after adjusting for other covariates and confounders. Conclusion: Results suggest that non-specific respiratory symptoms, decreasing lung function, and increasing airway responsiveness are early pulmonary responses to cotton dust. In addition, the occurrence of respiratory symptoms and increasing airway responsiveness, as well as atopy, may be important predictors for acute changes in lung function among cotton textile workers. PMID:12554839

Wang, X; Pan, L; Zhang, H; Sun, B; Dai, H; Christiani, D

2003-01-01

39

Observational Studies of Early-type Overcontact Binaries: TU Muscae  

E-print Network

We present new spectroscopic and photometric data on the early-type overcontact binary TU Muscae. The analysis of the spectroscopic data shows that the line of sight to the system crosses three kinematically sharp and well-separated interstellar reddening sources and that the stars rotate synchronously. We present new radial velocities that are in good agreement with earlier optical velocities and, thus, do not confirm the systematically smaller velocities obtained from IUE spectra. The optical velocities are analyzed simultaneously with the photometric data to derive accurate absolute dimesions for the binary components.The results show that TU Mus consists of an O7.5 primary with M_1=23.5 +/- 0.8 M_sun, R_1=7.48 +/- 0.08 R_sun and an O9.5 secondary with M_2=15.3 +/- 0.4 M_sun, R_2=6.15 +/- 0.07 R_sun in an overcontact configuration and that the orbital period has remained constant over the three decades covered by the observations. These results might imply that the mass transfer seen in late-type overcontact binaries does not occur in their early-type counterparts.

Dirk Terrell; Ulisse Munari; Tomaz Zwitter; Robert Nelson

2003-09-12

40

Early Hinode Observations of a Solar Filament Eruption  

NASA Technical Reports Server (NTRS)

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.

Sterling, Alphonse C.; Moore, Ronald L.

2007-01-01

41

Observation of multiple intermediates in ?-synuclein fibril formation by singular value decomposition analysis  

Microsoft Academic Search

One of the most well known characteristics for Parkinson’s disease (PD) is a polymerization of wild-type or mutant ?-synuclein into aggregates and fibrils, commonly observed as Lewy bodies and Lewy neuritis in PD patients. Although numerous studies on ?-synuclein fibrillation have been reported, the molecular mechanisms of aggregation and fibrillation are not well understood yet. In the present study, structural

Tomoaki Kamiyoshihara; Masaki Kojima; Kenji Uéda; Mitsuru Tashiro; Sakurako Shimotakahara

2007-01-01

42

CONSTRAINING PERTURBATIVE EARLY DARK ENERGY WITH CURRENT OBSERVATIONS  

SciTech Connect

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 w{sub m} {approx_gt} -0.1 at early times, which could lead to an EDE density of up to {Omega}{sub DE}(z{sub CMB})= 0.03{Omega}{sub m}(z{sub CMB}). Our analysis shows that marginalizing over the non-DE parameters such as {Omega}{sub m}, H{sub 0}, andn{sub s} , current CMB observations alone can constrain the scale factor of transition from EDE to late-time dark energy to a{sub t} {approx_gt} 0.44 and width of transition to {Delta}{sub t} {approx_lt} 0.37. The equation of state at present is somewhat weakly constrained to w{sub 0} {approx_lt} -0.6, if we allow H{sub 0} < 60 km s{sup -1} Mpc{sup -1}. Taken together with other observations, such as SNe, Hubble Space Telescope, and Sloan Digital Sky Survey luminous red galaxies, w{sub 0} is constrained much more tightly to w{sub 0} {approx_lt} -0.9, while redshift of transition and width of transition are also tightly constrained to a{sub t} {approx_lt} 0.19 and{Delta}{sub t} {approx_lt} 0.21. The evolution of the equation of state for EDE models is thus tightly constrained to {Lambda}CDM-like behavior at low redshifts. Incorrectly assuming dark energy perturbations to be negligible leads to different constraints on the equation of state parameters-w{sub 0} {approx_lt} -0.8, a{sub t} {approx_lt} 0.33, and{Delta}{sub t} {approx_lt} 0.31, thus highlighting the necessity of self-consistently including dark energy perturbations in the analysis. If we allow the spatial curvature to be a free parameter, then the constraints are relaxed to w{sub 0} {approx_lt} -0.77, a{sub t} {approx_lt} 0.35, and{Delta}{sub t} {approx_lt} 0.35 with -0.014 < {Omega}{sub {kappa}} < 0.031 for CMB + other observations. For perturbed EDE models, the 2{sigma} lower limit on {sigma}{sub 8} ({sigma}{sub 8} {>=} 0.59) is much lower than that in {Lambda}CDM ({sigma}{sub 8} {>=} 0.72), thus raising the interesting possibility of discriminating EDE from {Lambda}CDM using future observations such as halo mass functions or the Sunyaev-Zeldovich power spectrum.

Alam, Ujjaini [ISR-1, ISR Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2010-05-10

43

Decomposition of rice residues in tropical soils  

Microsoft Academic Search

The acetylene-reducing activity of waterlogged soils was stimulated by the incorporation of rice straw at a relatively early stage of its decomposition. The straw caused a decrease in the inorganic nitrogen and in redox potential, making a favorable environment for N2-fixing bacteria. But the stimulation of nitrogen fixation was observed only when the soils were kept waterlogged. Soils of Maahas

Tadakatsu Yoneyama; Kuk-Ki Lee; Tomio Yoshida

1977-01-01

44

Decomposition of the observed surface temperature with the Multi-channel Singular-Spectrum Analysis.  

NASA Astrophysics Data System (ADS)

Climate of the twentieth century is shaped by its natural variability and response to the anthropogenic activity. Therefore to predict the future climate, response of the climate to greenhouse-gas concentrations has to be well understood. As such response may be masked by natural climate oscillations, it is important to separate those components. In this study, Multi-channel Singular-Spectrum Analysis (M-SSA) is applied to the available observational data sets. Those data sets are global fields of surface/sea surface temperature: Met Office HadCRUT4, HadISST and Reynolds OI. With an application of M-SSA, four oscillatory components were found to explain large part of temperature variability. Time scale of derived components varies from an annual to interdecadal. Significant components resemble features of some already identified climate signals, like Atlantic Multidecadal Oscillation, which influences both the Atlantic and North Pacific. Additional analysis is made to assess the physical relevancy of the Pacific Decadal Oscillation (PDO). We test the hypothesis, whether PDO index can be reconstructed with derived oscillatory components. Further analysis aims to discuss statistical significance, physical relevancy of all derived modes and capability of the method to separate natural signal from anthropogenic one in the short and noisy time series.

Barcikowska, Monika; Knutson, Tom

2014-05-01

45

Supernova 2008J: early time observations of a heavily reddened SN 2002ic-like transient  

NASA Astrophysics Data System (ADS)

Aims: We provide additional observational evidence that some Type Ia supernovae (SNe Ia) show signatures of circumstellar interaction (CSI) with hydrogen-rich material. Methods: Early phase optical and near-infrared (NIR) light curves and spectroscopy of SN 2008J obtained by the Carnegie Supernova Project are studied and compared to those of SNe 2002ic and 2005gj. Our NIR spectrum is the first obtained for a 2002ic-like object extending up to 2.2 ?m. A published high-resolution spectrum is used to provide insight on the circumstellar material (CSM). Results: SN 2008J is found to be affected by AV ~ 1.9 mag of extinction and to closely resemble SN 2002ic. Spectral and color comparison to SNe 2002ic and 2005gj suggests RV < 3.1. Spectral decomposition reveals the underlying SN emission matches a 1991T-like event and, since SN 2008J is as luminous as SN 2005gj (Vmax = -20.3 mag), we conclude that their CSI emissions are similarly robust. The high-resolution spectrum reveals narrow emission lines produced from un-shocked gas characterized by a wind velocity of ~50 km s-1. We conclude that SN 2008J best matches an explosion of a SN Ia that interacts with its CSM. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (ESO Programme 080.A-0516).Figure 4 and Tables 1-6 are available in electronic form at http://www.aanda.org

Taddia, F.; Stritzinger, M. D.; Phillips, M. M.; Burns, C. R.; Heinrich-Josties, E.; Morrell, N.; Sollerman, J.; Valenti, S.; Anderson, J. P.; Boldt, L.; Campillay, A.; Castellon, S.; Contreras, C.; Folatelli, G.; Freedman, W. L.; Hamuy, M.; Krzeminski, W.; Leloudas, G.; Maeda, K.; Persson, S. E.; Roth, M.; Suntzeff, N. B.

2012-09-01

46

Early and Late Effects of Morphological Decomposition: Brain Correlates of Family Size Effects on Complex Words and Pseudowords  

Microsoft Academic Search

Summary In three ERP experiments, morphology-based decomposition of words and pseudowords was explored in Spanish. Subjects were asked to perform a lexical decision task on morphologically simple (e.g. 'sun') and complex (e.g. 'allerg+ic', 'allerg+ist') word strings, while family size for both lexemes\\/stems (S-FS) and morphemes\\/suffixes (M-FS) was varied. In Experiment I, earlier results by Schreuder & Baayen (1997) were replicated:

Javier S. Sainz; Departmento de Filología

47

Early HiRISE Observations of Fluvial and Hydrothermal Features  

Microsoft Academic Search

Fluvial and hydrothermal features are a key target for the HiRISE camera. Here we summarize some of the highlights of the early HiRISE imaging of fluvial features, paying special attention to the many spectacular images of gullies already obtained by the

V. C. Gulick; A. S. McEwen

2007-01-01

48

Observations of cloud condensation nuclei in Mt. Huang: instrumentation and early observations  

NASA Astrophysics Data System (ADS)

A new commercial instrument for measuring Cloud Condensation Nuclei (CCN), the Droplet Measurement Technologies Cylindrical Continuous-Flow Streamwise Thermal Gradient CCN Chamber (CFSTGC), installed on Mount Huang meteorological station (30°19'N, 118°14'E, 1840m above sea level) from 16 April to 28 July 2008. This instrument can measure CCN concentrations at supersaturations from 0.1% to 2% (potentially up to 6%), as well as a 1 Hz sampling rate that is sufficient for ground-based or airborne platform operation. The instrument records data continuously at 1-second intervals 24 hours a day. For the 98-day, continuous study the average CCN concentration was found to range between a few hundred and a few thousand nuclei per cm3 at supersaturations between 0.3 and 1%. Diurnal variations were observed, as well as other possible influences, such as wind speed, wind direction and mixing depth. At a constant supersaturation of 0.5% the CCN concentration is typically on the order of 361 to 2297 nuclei per cm3. A description of the instrumentation and early observations are presented and discussed.

Chen, Kui; Yin, Yan; Chen, Chen; Yang, Weifeng; Deng, Wei; Hu, Zhenghua; Wu, Fangfang

2009-07-01

49

Exploring A Decomposition Community  

NSDL National Science Digital Library

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.

LaRae Mikkelson, Ellen Hopkins Elementary, Moorhead, MN

2012-03-19

50

Child Observation as Teachers' Work in Contemporary Australian Early Childhood Programmes.  

ERIC Educational Resources Information Center

Examines how early childhood teachers in one Australian state use child observations. Argues that the current economic/political climate has produced changes for early childhood settings and that how teachers respond to changes regarding child observation depends on their work context. Suggests that the purpose of observation is changing and that…

Grieshaber, Susan; Halliwell, Gail; Hatch, J. Amos; Walsh, Kerryann

2000-01-01

51

The Swift XRT: Observations of Early X-ray Afterglows  

SciTech Connect

During the first year of operations of the Swift observatory, the X-ray Telescope has made a number of discoveries concerning the nature of X-ray afterglows of both long and short GRBs. We highlight the key findings, which include rapid declines at early times, a standard template of afterglow light curve shapes, common flaring, and the discovery of the first short GRB afterglow.

Burrows, David N.; Kennea, J. A.; Nousek, J. A. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Osborne, J. P.; O'Brien, P. T. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Chincarini, G. [INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, 23807 Merate (Italy); Universita degli studi di Milano-Bicocca, Piazza delle Scienze 3, 20126 Milan (Italy); Tagliaferri, G. [INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, 23807 Merate (Italy); Giommi, P. [ASI Science Data Center, via Galileo Galilei, 00044 Frascati (Italy); Zhang, B. [Department of Physics, University of Nevada, Box 454002, Las Vegas, NV 89154-4002 (United States)

2006-05-19

52

Innovation in observation: a vision for early outbreak detection  

PubMed Central

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

Fefferman, NH; Naumova, EN

2010-01-01

53

Observed ethnic-racial socialization and early adolescent adjustment .  

E-print Network

??This dissertation examined how cultural influences transmitted within the familial context impact the psychological adjustment of ethnic minority youth through the development of an observational… (more)

Yasui, Miwa

2008-01-01

54

Observations of the temporal variation in chemical content of decomposition fluid: A preliminary study using pigs as a model system  

Microsoft Academic Search

In this paper we report the results of our preliminary studies into short chain fatty acids that have the potential to show reproducible patterns over certain postmortem intervals during decomposition in the absence of a soil matrix. Additional compounds that were detected, including several long chain fatty acids, were also investigated for their potential in estimating postmortem interval. Analysis of

Lisa Swann; Shari Forbes; Simon W. Lewis

2010-01-01

55

Ethanol Decomposition on Ni(111): Observation of Ethoxy Formation by IRAS and Other Methods. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

The first step in the decomposition of chemisorbed ethanol on Ni(111) has been investigated using IRAS, XPS and TPD methods. Ethanol decomposes via a first step in which 0-H bond scission occurs. This reaction starts from a chemisorbed ethanol structure w...

J. Xu X. Zhang, R. Zenobi, J. Ylshinobu, Z. Xu

1991-01-01

56

Observational Studies of Early-type Binary Stars: MP Centauri  

E-print Network

We present photometric and spectroscopic data on the early-type binary MP Centauri. The photometric data are analyzed simultaneously with radial velocities to derive preliminary absolute dimensions for the binary components. Analysis of the spectra shows that the stars rotate synchronously and that the line of sight to the system crosses two kinematically sharp and well-separated interstellar reddening sources. It is shown that MP Cen consists of a B3 primary with M_1 = 11.4 +/- 0.4 M_sun, R_1 = 7.7 +/- 0.1 R_sun and a lobe-filling B6-B7 secondary with M_2 = 4.4 +/- 0.2 M_sun, R_2 = 6.6 +/- 0.1 R_sun

Dirk Terrell; Ulisse Munari; Tomaz Zwitter; George Wolf

2005-03-29

57

An Observational Study of the Interactions of Socially Withdrawn/Anxious Early Adolescents and Their Friends  

ERIC Educational Resources Information Center

Background: The friendships of socially withdrawn/anxious children and early adolescents have been found to lack critical rewarding qualities. Observational research may help elucidate the obstacles they face in forming and maintaining high-quality friendships with sociable peers. Method: We observed the interactions of 38 socially withdrawn early…

Schneider, Barry H.

2009-01-01

58

Observable relic features of soliton stars from early Universe.  

NASA Astrophysics Data System (ADS)

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.

Chiu, Hong-Yee

59

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

SciTech Connect

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.

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

60

Observational studies of early-type binary stars: VV Orionis  

E-print Network

New and previously published observations of the bright eclipsing binary VV Orionis are analyzed. We present new radial velocities and interstellar reddening measurements from high-resolution spectra of this detached, short-period (P=1.48 d) binary. We discuss the validity of prior claims for the existence of a third body and show that our new velocities and light curve solution cast doubt on them. The components of VV Ori are shown to be a B1 V primary with a mass $M{_1}=10.9 \\pm 0.1 M_{\\sun}$ and a radius $R_{1}=4.98 \\pm 0.02 R_{\\sun}$ and a B4.5 V secondary with a mass $M{_2}=4.09 \\pm 0.05 M_{\\sun}$ and a radius $R_{2}=2.41 \\pm 0.01 R_{\\sun}$.

Dirk Terrell; Ulisse Munari; Alessandro Siviero

2006-10-06

61

Dust and Molecules in Early Galaxies: Prediction and Strategy for Observations  

E-print Network

The interplay between dust and molecules is of fundamental importance in early galaxy evolution. First we present the prediction for the dust emission from forming galaxies. Then we discuss the observational strategy for molecules in early galaxies by infrared absorption lines of a bright continuum source behind the clouds. By combining these two approaches, we will be able to have a coherent picture of the very early stage of galaxy evolution.

Tsutomu T. Takeuchi

2005-09-28

62

Thermal decomposition of nitrated tributyl phosphate  

SciTech Connect

Extended contact between heated mixtures of tri-n-butyl phosphate (TBP) and aqueous solutions of nitric acid and/or heavy metal nitrate salts at elevated temperatures can lead to exothermic reactions of explosive violence. Most solvent extraction operations are conducted at ambient conditions without heating TBP and have been performed safely for decades, but several explosions involving TBP have occurred in the US, Canada, and the former Soviet Union. This investigation was undertaken to characterize the products of thermal decomposition of both single- and two-phase mixtures of TBP, nitric acid, and water under a variety of conditions. The data indicate that the extent of reaction and the rate of gaseous product formation are affected by the presence of Zr{sup 4+}, distillation compared with reflux conditions, temperature, water/HNO{sub 3} and HNO{sub 3}/TBP ratios, and whether the decomposition occurs under constant pressure or constant volume conditions. Higher reaction temperatures accelerate the rate of decomposition, but the extent of decomposition, as measured by the quantity of gaseous products, was greater at lower temperatures when the decomposition was performed under distillation conditions. Higher gas production occurs under reflux conditions, lower H{sub 2}O/HNO{sub 3} ratios, and when a separate water-HNO{sub 3} phase is initially present. The major gaseous products include N{sub 2}, CO, CO{sub 2}, NO, and N{sub 2}O. Measurable amounts of NO{sub 2} were not present in the final product mixture, although an orange color suggesting the presence of NO{sub 2} was observed in the early stages of decomposition. The major liquid products were dibutyl phosphoric acid, butyl nitrate, and water. Small amounts of C{sub 1}-C{sub 4} carboxylic acids were also present. Because of the small sample sizes that were employed and the isothermal conditions of the decomposition, runaway reactions were not observed. Some possible reaction pathways are considered.

Hou, Y.; Barefield, E.K.; Tedder, D.W.; Abdel-Khalik, S.I. [Georgia Inst. of Technology, Atlanta, GA (United States)

1996-03-01

63

Early fatigue damage in carbon-fibre composites observed by electrical resistance measurement  

Microsoft Academic Search

Early fatigue damage during the first tenth (or less) of the fatigue life was observed in carbon fibre composites by d.c. electrical resistance measurement. The damage was most severe in the first loading cycle and the incremental damage in each subsequent cycle diminished cycle by cycle. For the continuous carbon fibre carbon-matrix composite, the resistance increased irreversibly during early fatigue

S. Wang; X. Shui; X. Fu; D. D. L. Chung

1998-01-01

64

Basin-scale, integrated observations of the early 21st century multiyear drought  

E-print Network

Basin-scale, integrated observations of the early 21st century multiyear drought in southeast] The Murray-Darling Basin in southeast Australia is experiencing one of the most severe droughts observed. This paper provides new basin-scale observations of the multiyear drought, integrated to a degree rarely

Tregoning, Paul

65

LU Decomposition  

NSDL National Science Digital Library

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.

Fitchett, Stephanie; Smith, David

2010-06-07

66

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)

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.

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

2003-01-01

67

A New Observation Technique Applied to Early/Fast VLF Scattering Events  

NASA Astrophysics Data System (ADS)

Early/fast very low frequency (VLF, 3-30 kHz) events are understood to result from ionospheric conductivity changes associated with lightning. Early/fast amplitude and phase perturbations have been observed coincidentally with various optical observations of transient luminous events (TLEs), including elves, sprites, and sprite halos, each of which can have temporal characteristics consistent with those of early/fast VLF events. It is yet unresolved, however, whether a specific type of TLE is directly related to the ionospheric conductivity changes responsible for the typical early/fast event. In this paper, we present spread spectrum VLF scattering observations of early/fast events. The spread spectrum analysis technique determines the amplitude and phase of a subionospherically propagating VLF signal as a function of time during the early/fast event and as a function of frequency across the 200 Hz bandwidth of the VLF transmission. VLF scattering observations, each identified with causative lightning logged by the National Lightning Detection Network (NLDN), are compared with the predictions of the Long-Wave Propagation Capability (LWPC) code, a three-dimensional earth-ionosphere waveguide propagation and scattering model. Theoretical predictions for VLF scattering from ionization changes associated with elves are compared with those associated with sprite halos, and each are compared with experimental observations. Results indicate that the observed frequency dependence of VLF scattering during early/fast events results from the combination of scattering source properties and Earth-ionosphere waveguide propagation effects. Observations are more consistent with the modeled amplitude perturbations associated with sprite halos than those with elves.

Kotovsky, D. A.; Moore, R. C.

2012-12-01

68

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

Microsoft Academic Search

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,

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

2012-01-01

69

Thermal decomposition of hydrazines from reactive dynamics using the ReaxFF reactive force field.  

PubMed

We report reactive dynamics (RD) studies on: the decomposition of bulk hydrazine (N(2)H(4)); the decomposition of bulk monomethyl-hydrazine (CH(3)N(2)H(3)), hereafter referred to simply as methyl-hydrazine; the decomposition of hydrazine in the presence of hydrogen peroxide (H(2)O(2)); and decomposition hydrazine on catalytic surfaces Pt[100] and Pt[111] under various conditions. These studies use the ReaxFF reactive force field to describe the multitude of chemical reactions in these systems for a variety of reaction conditions in order to show that this approach leads to realistic decomposition mechanisms and rates. In particular, we determined how the decomposition of hydrazine is affected by temperature, pressure, and heating rate. We analyzed chemical reaction mechanism of the decomposition of hydrazine at the studied conditions and found that at lower temperatures the initial product from hydrazine decomposition is NH(3), whereas at higher temperatures H(2) and N(2) are the dominant early products. Prominent intermediates observed during these decompositions include N(2)H(3), N(2)H(2,) and NH(2), in agreement with quantum mechanical studies (7.3 ps at 3000 K). As the heating rate is decreased, the onset for hydrazine decomposition shifts to lower temperatures. Using a constant heating rate, we found that higher pressure (increased density) favors formation of NH(3) over N(2) and H(2). In studies of the catalytic decomposition of hydrazine on surfaces Pt[100] and Pt[111], we found that the presence of a Pt-catalyst reduces the initial decomposition temperature of hydrazine by about 50%. We found that the Pt[100]-surface is 20 times more active for hydrazine decomposition than the Pt[111]-surface, in qualitative agreement with experiments. These studies indicate how ReaxFF RD can be useful in understanding the chemical processes involved in bulk and catalytic decomposition and in oxidation of reactive species under various reaction conditions. PMID:19601597

Zhang, Luzheng; Duin, Adri C T van; Zybin, Sergey V; Goddard, William A

2009-08-01

70

X-Ray Emission from Early-Type Galaxies: A Complete Sample Observed by ROSAT  

Microsoft Academic Search

To test the cooling flow model of early-type galaxies, we obtained a complete\\u000amagnitude-limited sample of 34 early-type galaxies, observed with the PSPC and\\u000aHRI on ROSAT. The X-ray to optical distribution of galaxies implies a lower\\u000aenvelope that is consistent with the stellar emission inferred from Cen A. When\\u000athis stellar component is removed, the gaseous emission is related

Beth A. Brown; Joel N. Bregman

1997-01-01

71

Decomposition techniques  

USGS Publications Warehouse

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.

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

1992-01-01

72

Spread-spectrum VLF observations of early/fast and LEP events  

NASA Astrophysics Data System (ADS)

Subionospherically-propagating very low frequency (VLF) signals are sensitive to changes in the electrical properties of the D-region ionosphere. Lightning may produce such changes in the form of early/fast events and lightning-induced electron precipitation (LEP) events. While LEP events may be used to probe the energy distribution of electrons in the Earth's radiation belts, early/fast events are indicative of direct coupling of lightning energy to the overlying ionosphere and are closely associated with the occurrence of transient luminous events (TLEs). In this paper, we present observations of early/fast events and LEP events detected using narrowband (200-Hz) VLF transmitters. A spread-spectrum VLF analysis technique is employed to utilize the full 200-Hz bandwidth of the narrowband VLF signal and to analyze the effect of these events on VLF propagation as a function of frequency within the 200-Hz band. Observations underscore the utility of the spread-spectrum analysis technique.

Wang, T.; Moore, R. C.

2011-12-01

73

Factors Associated with South Korean Early Childhood Educators' Observed Behavior Support Strategies  

ERIC Educational Resources Information Center

This study was an exploratory study of 34 South Korean early childhood educators' strategies for addressing behavior problems in natural settings. Factors related to teachers' strategy implementation were also explored. Four specific teacher behaviors were observed: precorrection, behavioral-specific praise, redirection, and reprimand/punishment.…

Kim, Yeon Ha; Stormont, Melissa

2012-01-01

74

VOLUME 78, NUMBER 14 P H Y S I C A L R E V I E W L E T T E R S 7 APRIL 1997 X-ray Scattering Study of Early Stage Spinodal Decomposition in Al0.62Zn0.38  

E-print Network

of Early Stage Spinodal Decomposition in Al0.62Zn0.38 J. Mainville,* Y. S. Yang, K. R. Elder, and M. Sutton of equilibrium thermo- dynamics to provide the "driving force" for the transition. A quantitative comparison

Elder, Ken

75

NTO decomposition studies  

SciTech Connect

To examine the thermal decomposition of 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one (NTO) in detail, isotopic labeling studies were undertaken. NTO samples labeled with {sup 15}N in three different locations [N(1) and N(2), N(4), and N(6)] were prepared. Upon thermolysis, the majority of the NTO condensed-phase product was a brown, insoluble residue, but small quantities of 2,4-dihydro-3H-1,2,4-triazol-3-one (TO) and triazole were detected. Gases comprised the remainder of the NTO decomposition products. The analysis of these gases is reported along with mechanistic implications of these observations.

Oxley, J.C.; Smith, J.L.; Yeager, K.E.; Rogers, E.; Dong, X.X. [Univ. of Rhode Island, West Kingston, RI (United States)

1996-07-01

76

Swift Observations of GRB 050128: The Early X-Ray Afterglow  

NASA Astrophysics Data System (ADS)

Swift discovered GRB 050128 with the Burst Alert Telescope and promptly pointed its narrow field instruments to monitor the afterglow. X-ray observations started 108 s after the trigger time. The early decay of the afterglow is relatively flat, with a temporal decay modeled with a power-law index of ~-0.3. A steepening occurs at later times (~1500 s) with a power-law index of ~-1.3. During this transition, the observed X-ray spectrum does not change. We interpret this behavior as either an early jet break or evidence of a transition from the fast cooling regime to the slow cooling regime in a wind environment.

Campana, S.; Antonelli, L. A.; Chincarini, G.; Covino, S.; Cusumano, G.; Malesani, D.; Mangano, V.; Moretti, A.; Pagani, C.; Romano, P.; Tagliaferri, G.; Capalbi, M.; Perri, M.; Giommi, P.; Angelini, L.; Boyd, P.; Burrows, D. N.; Hill, J. E.; Gronwall, C.; Kennea, J. A.; Kobayashi, S.; Kumar, P.; Mészáros, P.; Nousek, J. A.; Roming, P. W. A.; Zhang, B.; Abbey, A. F.; Beardmore, A. P.; Breeveld, A.; Goad, M. R.; Godet, O.; Mason, K. O.; Osborne, J. P.; Page, K. L.; Poole, T.; Gehrels, N.

2005-05-01

77

The Formation History of Early-Type Galaxies: An Observational Perspective  

Microsoft Academic Search

This talk investigates the formation of early-type galaxies from a\\u000adeliberately observational view point. I begin by reviewing the conclusions\\u000athat can be reached by comparing the detailed properties of galaxies in\\u000apresent-day clusters, focusing on the colour-magnitude relation in particular.\\u000aThe overriding picture is one of homogeneity, implying a remarkable uniformity\\u000ain the formation of these galaxies. This picture

Richard G. Bower; Ale Terlevich; Tadayuki Kodama; Nelson Caldwell

1998-01-01

78

The Formation History of Early-Type Galaxies: an Observational Perspective  

Microsoft Academic Search

This talk investigates the formation of early-type galaxies from a deliberately observational view point. I begin by reviewing the conclusions that can be reached by comparing the detailed properties of galaxies in present-day clusters, focusing on the colour-magnitude relation in particular. The overriding picture is one of homogeneity, implying a remarkable uniformity in the formation of these galaxies. This picture

R. G. Bower; A. Terlevich; T. Kodama; N. Caldwell

1999-01-01

79

ROSAT PSPC observation of the X-ray faint early-type galaxy NGC5866  

E-print Network

We present the results of the analysis of the ROSAT PSPC pointed observation of the S0 galaxy NGC5866. Previous Einstein observations had revealed that this galaxy has a low X-ray to optical ratio Lx/Lb. Theoretical models of the X-ra emission of early-type galaxies had suggested that in objects of this kind the emission is not dominated by the presence of a hot diffuse gas, but should originate in stellar sources. We discuss the evidence in favor of this hypothesis following from the results of the analysis of the ROSAT PSPC data. The X-ray spectrum shows properties similar to those of the other two low Lx/Lb early-type galaxies observed by ROSAT so far, including the presence of very soft emission. So, these galaxies can be recognized as a group with homogeneous properties, and a more exhaustive picture of the nature of the X-ray emission across the Lx/Lb plane of early-type galaxies can be outlined. We also discuss the importance of rotation in the X-ray emission of S0 galaxies, and suggest that it could explain why on average S0s are less X-ray luminous than ellipticals.

S. Pellegrini

1994-07-03

80

Envisaged in-situ dust observations in the early comet orbit phase of ROSETTA  

NASA Astrophysics Data System (ADS)

The detection and analysis of icy grains ejected off comet 67P/Churyumov-Gerasimenko is one of the observational science themes of the COSIMA instrument onboard ROSETTA. Due to their short lifetime, icy grains have be collected in the very vicinity of the nucleus and in the early Rosetta mission phase before the snow line crossing. COSIMA is a secondary ion mass spectrometer, collecting dust grains on metal targets, imaging the grains with a microscope and analyzing the composition of the dust grains with a high resolution time-of-flight mass spectrometer. We will discuss the potential observations in view of the recent Enceladus icy grain detections onboard CASSINI.

Hilchenbach, M.; Engrand, C.; Krueger, H.; Cottin, H.; Silen, J. V.; Briois, C.

2012-12-01

81

Early GRB optical and infrared afterglow observations with the 2-m robotic Liverpool Telescope  

NASA Astrophysics Data System (ADS)

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.

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

2005-07-01

82

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

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

83

Constraining the temperature history of the past millennium using early instrumental observations  

NASA Astrophysics Data System (ADS)

The current assessment that twentieth-century global temperature change is unusual in the context of the last thousand years relies on estimates of temperature changes from natural proxies (tree-rings, ice-cores etc.) and climate model simulations. Confidence in such estimates is limited by difficulties in calibrating the proxies and systematic differences between proxy reconstructions and model simulations - notable differences include large differences in multi-decadal variability between proxy reconstructions, and big uncertainties in the effect of volcanic eruptions. Because the difference between the estimates extends into the relatively recent period of the early nineteenth century it is possible to compare them with a reliable instrumental estimate of the temperature change over that period, provided that enough early thermometer observations, covering a wide enough expanse of the world, can be collected. By constraining key aspects of the reconstructions and simulations, instrumental observations, inevitably from a limited period, can reduce reconstruction uncertainty throughout the millennium. A considerable quantity of early instrumental observations are preserved in the world's archives. One organisation which systematically made observations and collected the results was the English East-India Company (EEIC), and 900 log-books of EEIC ships containing daily instrumental measurements of temperature and pressure have been preserved in the British Library. Similar records from voyages of exploration and scientific investigation are preserved in published literature and the records in National Archives. Some of these records have been extracted and digitised, providing hundreds of thousands of new weather records offering an unprecedentedly detailed view of the weather and climate of the late eighteenth and early nineteenth centuries. The new thermometer observations demonstrate that the large-scale temperature response to the Tambora eruption and the 1809 eruption was modest (perhaps 0.5C). This provides a powerful out-of-sample validation for the proxy reconstructions --- supporting their use for longer-term climate reconstructions. However, some of the climate model simulations in the CMIP5 ensemble show much larger volcanic effects than this --- such simulations are unlikely to be accurate in this respect.

Brohan, P.

2012-12-01

84

Constraining the temperature history of the past millennium using early instrumental observations  

NASA Astrophysics Data System (ADS)

The current assessment that twentieth-century global temperature change is unusual in the context of the last thousand years relies on estimates of temperature changes from natural proxies (tree-rings, ice-cores etc.) and climate model simulations. Confidence in such estimates is limited by difficulties in calibrating the proxies and systematic differences between proxy reconstructions and model simulations. As the difference between the estimates extends into the relatively recent period of the early nineteenth century it is possible to compare them with a reliable instrumental estimate of the temperature change over that period, provided that enough early thermometer observations, covering a wide enough expanse of the world, can be collected. One organisation which systematically made observations and collected the results was the English East-India Company (EEIC), and their archives have been preserved in the British Library. Inspection of those archives revealed 900 log-books of EEIC ships containing daily instrumental measurements of temperature and pressure, and subjective estimates of wind speed and direction, from voyages across the Atlantic and Indian Oceans between 1789 and 1834. Those records have been extracted and digitised, providing 273 000 new weather records offering an unprecedentedly detailed view of the weather and climate of the late eighteenth and early nineteenth centuries. The new thermometer observations demonstrate that the large-scale temperature response to the Tambora eruption and the 1809 eruption was modest (perhaps 0.5 °C). This provides a powerful out-of-sample validation for the proxy reconstructions - supporting their use for longer-term climate reconstructions. However, some of the climate model simulations in the CMIP5 ensemble show much larger volcanic effects than this - such simulations are unlikely to be accurate in this respect.

Brohan, P.; Allan, R.; Freeman, E.; Wheeler, D.; Wilkinson, C.; Williamson, F.

2012-05-01

85

Constraining the temperature history of the past millennium using early instrumental observations  

NASA Astrophysics Data System (ADS)

The current assessment that twentieth-century global temperature change is unusual in the context of the last thousand years relies on estimates of temperature changes from natural proxies (tree-rings, ice-cores, etc.) and climate model simulations. Confidence in such estimates is limited by difficulties in calibrating the proxies and systematic differences between proxy reconstructions and model simulations. As the difference between the estimates extends into the relatively recent period of the early nineteenth century it is possible to compare them with a reliable instrumental estimate of the temperature change over that period, provided that enough early thermometer observations, covering a wide enough expanse of the world, can be collected. One organisation which systematically made observations and collected the results was the English East India Company (EEIC), and their archives have been preserved in the British Library. Inspection of those archives revealed 900 log-books of EEIC ships containing daily instrumental measurements of temperature and pressure, and subjective estimates of wind speed and direction, from voyages across the Atlantic and Indian Oceans between 1789 and 1834. Those records have been extracted and digitised, providing 273 000 new weather records offering an unprecedentedly detailed view of the weather and climate of the late eighteenth and early nineteenth centuries. The new thermometer observations demonstrate that the large-scale temperature response to the Tambora eruption and the 1809 eruption was modest (perhaps 0.5 °C). This provides an out-of-sample validation for the proxy reconstructions - supporting their use for longer-term climate reconstructions. However, some of the climate model simulations in the CMIP5 ensemble show much larger volcanic effects than this - such simulations are unlikely to be accurate in this respect.

Brohan, P.; Allan, R.; Freeman, E.; Wheeler, D.; Wilkinson, C.; Williamson, F.

2012-10-01

86

Rare examples of early VLF events observed in association with ISUAL-detected gigantic jets  

NASA Astrophysics Data System (ADS)

We examine narrowband VLF observations and investigate the association of early VLF perturbations with gigantic jets recorded by the Imager of Sprites and Upper Atmospheric Lightnings (ISUAL) instrument aboard FORMOSAT-2. From its inception in 2004 to April 2013, the ISUAL instrument has recorded 90 gigantic jets using a triggered camera. Stanford VLF receivers located around the world are used to detect perturbations to VLF transmitter signals associated with lightning. While nine gigantic jet events occurred within 100 km of a VLF transmitter-receiver great circle path, only four early VLF events were detected in association with three ISUAL gigantic jets. One of these is a moderate event of 0.4 dB amplitude change, and the others are very small. The recovery time of these events are less than a couple of minutes and so do not constitute the "long recovery" early VLF events that have been postulated to be associated with gigantic jets. We speculate on possible explanations for the lack of other events on monitored paths, including a lack of significant ionization produced in the D region ionosphere by the gigantic jet event, weak transmitter signals recorded by the receivers, or mode effects on transmitter paths.

Marshall, R. A.; Adachi, T.; Hsu, R.-R.; Chen, A. B.

2014-01-01

87

Interactions of tissue and fertilizer nitrogen on decomposition dynamics of lignin-rich conifer litter  

USGS Publications Warehouse

High tissue nitrogen (N) accelerates decomposition of high-quality leaf litter in the early phases of mass loss, but the influence of initial tissue N variation on the decomposition of lignin-rich litter is less resolved. Because environmental changes such as atmospheric N deposition and elevated CO2 can alter tissue N levels within species more rapidly than they alter the species composition of ecosystems, it is important to consider how within-species variation in tissue N may shape litter decomposition and associated N dynamics. Douglas-fir (Pseudotsuga menziesii ) is a widespread lignin-rich conifer that dominates forests of high carbon (C) storage across western North America, and displays wide variation in tissue and litter N that reflects landscape variation in soil N. We collected eight unique Douglas-fir litter sources that spanned a two-fold range in initial N concentrations (0.67–1.31%) with a narrow range of lignin (29–35%), and examined relationships between initial litter chemistry, decomposition, and N dynamics in both ambient and N fertilized plots at four sites over 3 yr. High initial litter N slowed decomposition rates in both early (0.67 yr) and late (3 yr) stages in unfertilized plots. Applications of N fertilizer to litters accelerated early-stage decomposition, but slowed late-stage decomposition, and most strongly affected low-N litters, which equalized decomposition rates across litters regardless of initial N concentrations. Decomposition of N-fertilized litters correlated positively with initial litter manganese (Mn) concentrations, with litter Mn variation reflecting faster turnover of canopy foliage in high N sites, producing younger litterfall with high N and low Mn. Although both internal and external N inhibited decomposition at 3 yr, most litters exhibited net N immobilization, with strongest immobilization in low-N litter and in N-fertilized plots. Our observation for lignin-rich litter that high initial N can slow decomposition yet accelerate N release differs from findings where litter quality variation across species promotes coupled C and N release during decomposition. We suggest reevaluation of ecosystem models and projected global change effects to account for a potential decoupling of ecosystem C and N feedbacks through litter decomposition in lignin-rich conifer forests.

Perakis, Steven S.; Matkins, Joselin J.; Hibbs, David E.

2012-01-01

88

Chemically Driven Spinodal Decomposition  

Microsoft Academic Search

Thermally driven spinodal decomposition in polymer\\/polymer systems is often observed through the growth of a peak in the small-angle light scattering pattern. Phase growth is related to an increase in intensity with time following Cahn-Hillard theory. Latter stage deviations from this thermodynamic prediction are described by Oswald ripening mechanisms. A parallel to thermally driven phase separation is seen in some

S. Sukumaran; G. Beaucage; B. Viers; J. E. Mark; M. Saraf

1997-01-01

89

[Contribution of soil fauna to the mass loss of Betula albosinensis leaf litter at early decomposition stage of subalpine forest litter in western Sichuan].  

PubMed

In order to quantify the contribution of soil fauna to the decomposition of birch (Betula albosinensis) leaf litter in subalpine forests in western Sichuan of Southwest China during freeze-thaw season, a field experiment with different mesh sizes (0.02, 0.125, 1 and 3 mm) of litterbags was conducted in a representative birch-fir (Abies faxoniana) forest to investigate the mass loss rate of the birch leaf litter from 26 October, 2010 to 18 April, 2011, and the contributions of micro-, meso- and macro-fauna to the decomposition of the leaf litter. Over the freeze-thaw season, 11.8%, 13.2%, 15.4% and 19.5% of the mass loss were detected in the litterbags with 0.02, 0. 125, 1 and 3 mm mesh sizes, respectively. The total contribution of soil fauna to the litter decomposition accounted for 39.5% of the mass loss, and the taxa and individual relative density of the soil fauna in the litterbags had the similar variation trend with that of the mass loss rate. The contribution rate of soil fauna to the leaf litter mass loss showed the order of micro- < meso- < macro-fauna, with the highest contribution of micro-fauna (7.9%), meso-fauna (11.9%), and macro-fauna (22.7%) at the onset of freezing stage, deeply frozen stage, and thawing stage, respectively. The results demonstrated that soil fauna played an important role in the litter decomposition in subalpine forests of western Sichuan during freeze-thaw season. PMID:22586951

Xia, Lei; Wu, Fu-Zhong; Yang, Wan-Qin; Tan, Bo

2012-02-01

90

Prelexical Decomposition of Compound and Pseudocompound Words  

E-print Network

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 ...

Diener, Un So Park

2007-12-12

91

Experimental observation of critical slowing down as an early warning of population collapse  

NASA Astrophysics Data System (ADS)

Near tipping points marking population collapse or other critical transitions in complex systems small changes in conditions can result in drastic shifts in the system state. In theoretical models it is known that early warning signals can be used to predict the approach of these tipping points (bifurcations), but little is known about how these signals can be detected in practice. Here we use the budding yeast Saccharomyces cerevisiae to study these early warning signals in controlled experimental populations. We grow yeast in the sugar sucrose, where cooperative feeding dynamics causes a fold bifurcation; falling below a critical population size results in sudden collapse. We demonstrate the experimental observation of an increase in both the size and timescale of the fluctuations of population density near this fold bifurcation. Furthermore, we test the utility of theoretically predicted warning signals by observing them in two different slowly deteriorating environments. These findings suggest that these generic indicators of critical slowing down can be useful in predicting catastrophic changes in population biology.

Vorselen, Daan; Dai, Lei; Korolev, Kirill; Gore, Jeff

2012-02-01

92

Fast Approximate Convex Decomposition  

E-print Network

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...

Ghosh, Mukulika

2012-10-19

93

Thermal decomposition of lithium peroxide  

Microsoft Academic Search

1.A study was made of the thermal decomposition of lithium peroxide under static conditions in the temperature range 270–320‡.2.The formation of solid Li2O2-Li2O solution is observed up to a degree of Li2O2 conversion of approximately 50%. The apparent activation energy for the decomposition of Li2O2 is 50 kcal\\/mole

A. B. Tsentsiper; Z. I. Kuznetsova

1965-01-01

94

EARLY PHASE OBSERVATIONS OF EXTREMELY LUMINOUS TYPE Ia SUPERNOVA 2009dc  

SciTech Connect

We present early phase observations in optical and near-infrared wavelengths for the extremely luminous Type Ia supernova (SN Ia) 2009dc. The decline rate of the light curve is DELTAm{sub 15}(B) = 0.65 +- 0.03, which is one of the slowest among SNe Ia. The peak V-band absolute magnitude is estimated to be M{sub V} = -19.90 +- 0.15 mag if no host extinction is assumed. It reaches M{sub V} = -20.19 +- 0.19 mag if we assume the host extinction of A{sub V} = 0.29 mag. SN 2009dc belongs to the most luminous class of SNe Ia, like SNe 2003fg and 2006gz. Our JHK{sub s} -band photometry shows that this SN is also one of the most luminous SNe Ia in near-infrared wavelengths. We estimate the ejected {sup 56}Ni mass of 1.2 +- 0.3 M{sub sun} for the no host extinction case (and of 1.6 +- 0.4 M{sub sun} for the host extinction of A{sub V} = 0.29 mag). The C II lambda6580 absorption line remains visible until a week after the maximum brightness, in contrast to its early disappearance in SN 2006gz. The line velocity of Si II lambda6355 is about 8000 km s{sup -1} around the maximum, being considerably slower than that of SN 2006gz. The velocity of the C II line is similar to or slightly less than that of the Si II line around the maximum. The presence of the carbon line suggests that the thick unburned C+O layer remains after the explosion. Spectropolarimetric observations by Tanaka et al. indicate that the explosion is nearly spherical. These observational facts suggest that SN 2009dc is a super-Chandrasekhar mass SN Ia.

Yamanaka, M.; Arai, A.; Chiyonobu, S.; Fukazawa, Y.; Ikejiri, Y.; Itoh, R.; Komatsu, T.; Miyamoto, H. [Department of Physical Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan); Kawabata, K. S. [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kinugasa, K.; Hashimoto, O.; Honda, S. [Gunma Astronomical Observatory, Takayama, Gunma 377-0702 (Japan); Tanaka, M. [Department of Astronomy, School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Imada, A.; Kuroda, D. [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Kamogata, Asakuchi-shi, Okayama 719-0232 (Japan); Maeda, K.; Nomoto, K. [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa (Japan); Kamata, Y. [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); Kawai, N. [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Konishi, K., E-mail: myamanaka@hiroshima-u.ac.j [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8582 (Japan)

2009-12-20

95

VERY EARLY ULTRAVIOLET AND OPTICAL OBSERVATIONS OF THE TYPE Ia SUPERNOVA 2009ig  

SciTech Connect

Supernova (SN) 2009ig was discovered 17 hr after explosion by the Lick Observatory Supernova Search, promptly classified as a normal Type Ia SN (SN Ia), peaked at V = 13.5 mag, and was equatorial, making it one of the foremost SNe for intensive study in the last decade. Here, we present ultraviolet (UV) and optical observations of SN 2009ig, starting about 1 day after explosion until around maximum brightness. Our data include excellent UV and optical light curves, 25 premaximum optical spectra, and 8 UV spectra, including the earliest UV spectrum ever obtained of an SN Ia. SN 2009ig is a relatively normal SN Ia, but does display high-velocity ejecta-the ejecta velocity measured in our earliest spectra (v Almost-Equal-To -23, 000 km s{sup -1} for Si II {lambda}6355) is the highest yet measured in an SN Ia. The spectral evolution is very dramatic at times earlier than 12 days before maximum brightness, but slows after that time. The early-time data provide a precise measurement of 17.13 {+-} 0.07 days for the SN rise time. The optical color curves and early-time spectra are significantly different from template light curves and spectra used for light-curve fitting and K-corrections, indicating that the template light curves and spectra do not properly represent all SNe Ia at very early times. In the age of wide-angle sky surveys, SNe like SN 2009ig that are nearby, bright, well positioned, and promptly discovered will still be rare. As shown with SN 2009ig, detailed studies of single events can provide significantly more information for testing systematic uncertainties related to SN Ia distance estimates and constraining progenitor and explosion models than large samples of more distant SNe.

Foley, Ryan J.; Challis, P. J.; Marion, G. H.; Kirshner, R. P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Filippenko, A. V.; Ganeshalingam, M.; Li, W.; Silverman, J. M.; Cenko, S. B. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Landsman, W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Beaton, R. L. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Bennert, V. N. [Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States); Childress, M. [Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Guhathakurta, P. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Jiang, L. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Kalirai, J. S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Stockton, A. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Tollerud, E. J. [Center for Cosmology, Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); Vinko, J. [Department of Optics and Quantum Electronics, University of Szeged, Dom ter 9, Szeged H-6720 (Hungary); Wheeler, J. C., E-mail: rfoley@cfa.harvard.edu [Astronomy Department, University of Texas, Austin, TX 78712 (United States); and others

2012-01-01

96

CONSTRAINTS ON TYPE Ia SUPERNOVA PROGENITOR COMPANIONS FROM EARLY ULTRAVIOLET OBSERVATIONS WITH SWIFT  

SciTech Connect

We compare early ultraviolet (UV) observations of Type Ia supernovae (SNe Ia) with theoretical predictions for the brightness of the shock associated with the collision between SN ejecta and a companion star. Our simple method is independent of the intrinsic flux from the SN and treats the flux observed with the Swift/Ultra-Violet Optical Telescope as conservative upper limits on the shock brightness. Comparing this limit with the predicted flux for various shock models, we constrain the geometry of the SN progenitor-companion system. We find the model of a 1 M{sub Sun} red supergiant companion in Roche-lobe overflow to be excluded at a 95% confidence level for most individual SNe for all but the most unfavorable viewing angles. For the sample of 12 SNe taken together, the upper limits on the viewing angle are inconsistent with the expected distribution of viewing angles for red gaint stars as the majority of companions with high confidence. The separation distance constraints do allow main-sequence companions. A better understanding of the UV flux arising from the SN itself as well as continued UV observations of young SNe Ia will further constrain the possible progenitors of SNe Ia.

Brown, Peter J.; Dawson, Kyle S.; Harris, David W.; Olmstead, Matthew [Department of Physics and Astronomy, University of Utah, 115 South 1400 East 201, Salt Lake City, UT 84112 (United States); Milne, Peter [Steward Observatory, University of Arizona, Tucson, AZ 85719 (United States); Roming, Peter W. A. [Southwest Research Institute, Department of Space Science, San Antonio, TX 78238 (United States)

2012-04-10

97

Identification of old tidal dwarfs near early-type galaxies from deep imaging and HI observations  

E-print Network

It has recently been proposed that the dwarf spheroidal galaxies located in the Local Group disks of satellites (DoSs) may be tidal dwarf galaxies (TDGs) born in a major merger at least 5 Gyr ago. Whether TDGs can live that long is still poorly constrained by observations. As part of deep optical and HI surveys with the CFHT MegaCam camera and Westerbork Synthesis Radio Telescope made within the ATLAS3D project, and follow-up spectroscopic observations with the Gemini-North telescope, we have discovered old TDG candidates around several early-type galaxies. At least one of them has an oxygen abundance close to solar, as expected for a tidal origin. This confirmed pre-enriched object is located within the gigantic, but very low surface brightness, tidal tail that emanates from the elliptical galaxy, NGC 5557. An age of 4 Gyr estimated from its SED fitting makes it the oldest securely identified TDG ever found so far. We investigated the structural and gaseous properties of the TDG and of a companion located in...

Duc, Pierre-Alain; McDermid, Richard M; Cuillandre, Jean-Charles; Serra, Paolo; Bournaud, Frédéric; Cappellari, Michele; Emsellem, Eric

2014-01-01

98

Earth Observing System (EOS) Aqua Launch and Early Mission Attitude Support Experiences  

NASA Technical Reports Server (NTRS)

The Earth Observing System (EOS) Aqua satellite was successfully launched on May 4,2002. Aqua is the second in the series of EOS satellites. EOS is part of NASA s Earth Science Enterprise Program, whose goals are to advance the scientific understanding of the Earth system. Aqua is a three-axis stabilized, Earth-pointing spacecraft in a nearly circular, sun-synchronous orbit at an altitude of 705 km. The Goddard Space Flight Center (GSFC) Flight Dynamics attitude team supported all phases of the launch and early mission. This paper presents the main results and lessons learned during this period, including: real-time attitude mode transition support, sensor calibration, onboard computer attitude validation, response to spacecraft emergencies, postlaunch attitude analyses, and anomaly resolution. In particular, Flight Dynamics support proved to be invaluable for successful Earth acquisition, fine-point mode transition, and recognition and correction of several anomalies, including support for the resolution of problems observed with the MODIS instrument.

Tracewell, D.; Glickman, J.; Hashmall, J.; Natanson, G.; Sedlak, J.

2003-01-01

99

Early and Efficient Detection of Mycobacterium tuberculosis in Sputum by Microscopic Observation of Broth Cultures  

PubMed Central

Early, efficient and inexpensive methods for the detection of pulmonary tuberculosis are urgently needed for effective patient management as well as to interrupt transmission. These methods to detect M. tuberculosis in a timely and affordable way are not yet widely available in resource-limited settings. In a developing-country setting, we prospectively evaluated two methods for culturing and detecting M. tuberculosis in sputum. Sputum samples were cultured in liquid assay (micro broth culture) in microplate wells and growth was detected by microscopic observation, or in Löwenstein–Jensen (LJ) solid media where growth was detected by visual inspection for colonies. Sputum samples were collected from 321 tuberculosis (TB) suspects attending Bugando Medical Centre, in Mwanza, Tanzania, and were cultured in parallel. Pulmonary tuberculosis cases were diagnosed using the American Thoracic Society diagnostic standards. There were a total of 200 (62.3%) pulmonary tuberculosis cases. Liquid assay with microscopic detection detected a significantly higher proportion of cases than LJ solid culture: 89.0% (95% confidence interval [CI], 84.7% to 93.3%) versus 77.0% (95% CI, 71.2% to 82.8%) (p?=?0.0007). The median turn around time to diagnose tuberculosis was significantly shorter for micro broth culture than for the LJ solid culture, 9 days (interquartile range [IQR] 7–13), versus 21 days (IQR 14–28) (p<0.0001). The cost for micro broth culture (labor inclusive) in our study was US $4.56 per sample, versus US $11.35 per sample for the LJ solid culture. The liquid assay (micro broth culture) is an early, feasible, and inexpensive method for detection of pulmonary tuberculosis in resource limited settings. PMID:23469014

Kidenya, Benson R.; Kabangila, Rodrick; Peck, Robert N.; Mshana, Stephen E.; Webster, Lauren E.; Koenig, Serena P.; Johnson, Warren D.; Fitzgerald, Daniel W.

2013-01-01

100

Abundance Patterns in the Interstellar Medium of Early-type Galaxies Observed with Suzaku  

NASA Astrophysics Data System (ADS)

We have analyzed 17 early-type galaxies, 13 ellipticals and 4 S0 galaxies, observed with Suzaku, and investigated metal abundances (O, Mg, Si, and Fe) and abundance ratios (O/Fe, Mg/Fe, and Si/Fe) in the interstellar medium (ISM). The emission from each on-source region, which is four times the effective radius, r e, is reproduced with one-temperature (1T) or two-temperature (2T) thermal plasma models as well as a multi-temperature model, using APEC plasma code version 2.0.1. The multi-temperature model gave almost the same abundances and abundance ratios with the 1T or 2T models. The weighted averages of the O, Mg, Si, and Fe abundances of all the sample galaxies derived from the multi-temperature model fits are 0.83 ± 0.04, 0.93 ± 0.03, 0.80 ± 0.02, and 0.80 ± 0.02 solar, respectively, in solar units according to the solar abundance table by Lodders in 2003. These abundances show no significant dependence on the morphology and environment. The systematic differences in the derived metal abundances between versions 2.0.1 and 1.3.1 of the APEC plasma codes were investigated. The derived O and Mg abundances in the ISM agree with the stellar metallicity within an aperture with a radius of one r e derived from optical spectroscopy. From these results, we discuss the past and present Type Ia supernova rates and star formation histories in early-type galaxies.

Konami, Saori; Matsushita, Kyoko; Nagino, Ryo; Tamagawa, Toru

2014-03-01

101

Early and efficient detection of Mycobacterium tuberculosis in sputum by microscopic observation of broth cultures.  

PubMed

Early, efficient and inexpensive methods for the detection of pulmonary tuberculosis are urgently needed for effective patient management as well as to interrupt transmission. These methods to detect M. tuberculosis in a timely and affordable way are not yet widely available in resource-limited settings. In a developing-country setting, we prospectively evaluated two methods for culturing and detecting M. tuberculosis in sputum. Sputum samples were cultured in liquid assay (micro broth culture) in microplate wells and growth was detected by microscopic observation, or in Löwenstein-Jensen (LJ) solid media where growth was detected by visual inspection for colonies. Sputum samples were collected from 321 tuberculosis (TB) suspects attending Bugando Medical Centre, in Mwanza, Tanzania, and were cultured in parallel. Pulmonary tuberculosis cases were diagnosed using the American Thoracic Society diagnostic standards. There were a total of 200 (62.3%) pulmonary tuberculosis cases. Liquid assay with microscopic detection detected a significantly higher proportion of cases than LJ solid culture: 89.0% (95% confidence interval [CI], 84.7% to 93.3%) versus 77.0% (95% CI, 71.2% to 82.8%) (p?=?0.0007). The median turn around time to diagnose tuberculosis was significantly shorter for micro broth culture than for the LJ solid culture, 9 days (interquartile range [IQR] 7-13), versus 21 days (IQR 14-28) (p<0.0001). The cost for micro broth culture (labor inclusive) in our study was US $4.56 per sample, versus US $11.35 per sample for the LJ solid culture. The liquid assay (micro broth culture) is an early, feasible, and inexpensive method for detection of pulmonary tuberculosis in resource limited settings. PMID:23469014

Kidenya, Benson R; Kabangila, Rodrick; Peck, Robert N; Mshana, Stephen E; Webster, Lauren E; Koenig, Serena P; Johnson, Warren D; Fitzgerald, Daniel W

2013-01-01

102

The Martian atmosphere above great volcanoes: Early planetary Fourier spectrometer observations  

NASA Astrophysics Data System (ADS)

This work reports the first observations of the Martian atmosphere returned by the planetary Fourier spectrometer (PFS) on board of Mars express (MEX) satellite in the vicinity of the greatest volcanic domes of the planet. Two of the early MEX orbits have already covered the region of Olympus Mons and Ascraeus Mons. These measurements are very similar in terms of local time (14LT) and season ( L=337 and 342, respectively). The long wavelength channel (LWC) of the instrument works in the thermal IR (300-1500 cm -1); its data allow the simultaneous retrieval of surface temperature, integrated content of water ice and dust suspended in the atmosphere and air thermal field up to an altitude of about 50 km. Results of the code described in the companion paper by Grassi et al. for the two orbits are presented and compared with the state expected by the European Martian climate dataset v3.1. The parent global circulation model LMD-Oxford-AAS is able to take into account a wide number of physical phenomena, but the results included in EMCD are affected by a relatively coarse spatial resolution, that does not properly describe the great volcanic domes. The comparison demonstrated that observed data follow quite strictly the trends foreseen by the model in low altitude regions, while the behavior shows remarkable differences above the relief, where orography likely plays an important role. Namely, extended mid-altitude minima in air temperature fields above the summit of volcanic domes are observed. The integrated content of dust shows a minima above Olympus, as expected for a dust particle concentration that decays with height. Measurements are consistent with an exponential decay characterized by a scale height of ˜10 km. Consistently, the surface temperature presents a maxima over the dome, as expected for conditions of clearer sky. Water ice clouds are clearly detected around Ascreus Mons, with a strong asymmetry in latitude. Further comparison with the results of the thermal emission spectrometer (TES) on board of Mars global surveyor (MGS) is also provided, partially supporting our observations of air temperature fields. Possible explanation of these trends is represented by thermal circulation, driven by air heating close to the surface. If confirmed by future observations, these data can represent important constraint by PFS data to mesospheric simulation, with possible implications on the Global Circulation Models.

Grassi, D.; Fiorenza, C.; Zasova, L. V.; Ignatiev, N. I.; Maturilli, A.; Formisano, V.; Giuranna, M.

2005-08-01

103

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

SciTech Connect

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.

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

104

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

NASA Astrophysics Data System (ADS)

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.

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

2012-08-01

105

Abundance Patterns in the Interstellar Medium of Early-type Galaxies Observed with Suzaku  

E-print Network

We have analyzed 17 early-type galaxies, 13 ellipticals and 4 S0's, observed with Suzaku, and investigated metal abundances (O, Mg, Si, and Fe) and abundance ratios (O/Fe, Mg/Fe, and Si/Fe) in the interstellar medium (ISM). The emission from each on-source region, which is 4 times effective radius, r_e, is reproduced with one- or two- temperature thermal plasma models as well as a multi-temperature model, using APEC plasma code v2.0.1. The multi-temperature model gave almost the same abundances and abundance ratios with the 1T or 2T models. The weighted averages of the O, Mg, Si, and Fe abundances of all the sample galaxies derived from the multi-temperature model fits are 0.83+-0.04, 0.93+-0.03, 0.80+-0.02, and 0.80+-0.02 solar, respectively, in solar units according to the solar abundance table by Lodders (2003). These abundances show no significant dependence on the morphology and environment. The systematic differences in the derived metal abundances between the version 2.0.1 and 1.3.1 of APEC plasma code...

Konami, Saori; Nagino, Ryo; Tamagawa, Toru

2014-01-01

106

Early-time observations of Type Ia supernovae to reveal progenitors  

NASA Astrophysics Data System (ADS)

SNe Ia remain nature's best standardized candles, and yet their progenitors have long been a mystery. However, in a series of three studies this year, our group has placed the first serious constraints on the progenitors of two SNe Ia, finding (1) the first hard evidence that the primary is a CO white dwarf star; (2) in one case the white dwarf is accreting from a mass-losing evolved secondary and has become a recurrent nova like RS Oph; (3) in another case a system like RS Oph is ruled out and the companion is probably a main sequence star. Taken together with our earlier work implicating white dwarfs mergers in the super-Chandra systems, we are led to the remarkable conclusion that there are a multiplicity of progenitors for SNe Ia. This may explain our finding that supernovae in different environments correct to different absolute magnitudes, and could have serious implications for cosmology. Our results depend on early-time observations for which the queue-scheduled Gemini is uniquely suited. We will use these data to rapidly trigger high-resolution searches for circumstellar material at Keck and VLT, and the Gemini data will directly probe the unburned progenitor material in the supernovae themselves.

Howell, D. Andrew; Sullivan, Mark; Parrent, Jerod; Nugent, Peter; Hook, Isobel; Dilday, Ben; Maguire, Kate; Graham, Melissa

2012-02-01

107

Photopromoted and Thermal Decomposition of Nitric Oxide by Metal Oxides.  

National Technical Information Service (NTIS)

This technical report summarizes research on decomposition of NOx by photopromoted and thermal solid-catalyzed decomposition of NO. Typical catalysts incorporated one or more metal oxides. Photopromotion of catalytic activity was observed with several cat...

E. Berman, J. Dong, N. N. Lichtin

1992-01-01

108

Autonomous Gaussian Decomposition  

E-print Network

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 21cm absorption spectra from the 21cm SPectral line Observations of Neutral Gas with the EVLA (21-SPONGE) survey. We use AGD with Monte Carlo methods to derive the HI 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 up...

Lindner, Robert R; Murray, Claire E; Stanimirovi?, Snežana; Babler, Brian L; Heiles, Carl; Hennebelle, Patrick; Goss, W M; Dickey, John

2014-01-01

109

HUBBLE SPACE TELESCOPE WFC3 EARLY RELEASE SCIENCE: EMISSION-LINE GALAXIES FROM INFRARED GRISM OBSERVATIONS  

SciTech Connect

We present grism spectra of emission-line galaxies (ELGs) from 0.6 to 1.6 {mu}m from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope. These new infrared grism data augment previous optical Advanced Camera for Surveys G800L 0.6-0.95 {mu}m grism data in GOODS-South from the PEARS program, extending the wavelength coverage well past the G800L red cutoff. The Early Release Science (ERS) grism field was observed at a depth of two orbits per grism, yielding spectra of hundreds of faint objects, a subset of which is presented here. ELGs are studied via the H{alpha}, [O III], and [O II] emission lines detected in the redshift ranges 0.2 {approx}< z {approx}< 1.4, 1.2 {approx}< z {approx}< 2.2, and 2.0 {approx}< z {approx}< 3.3, respectively, in the G102 (0.8-1.1 {mu}m; R {approx_equal} 210) and G141 (1.1-1.6 {mu}m; R {approx_equal} 130) grisms. The higher spectral resolution afforded by the WFC3 grisms also reveals emission lines not detectable with the G800L grism (e.g., [S II] and [S III] lines). From these relatively shallow observations, line luminosities, star formation rates, and grism spectroscopic redshifts are determined for a total of 48 ELGs to m A{sub B(F098M)} {approx_equal} 25 mag. Seventeen GOODS-South galaxies that previously only had photometric redshifts now have new grism-spectroscopic redshifts, in some cases with large corrections to the photometric redshifts ({Delta}z {approx_equal} 0.3-0.5). Additionally, one galaxy had no previously measured redshift but now has a secure grism-spectroscopic redshift, for a total of 18 new GOODS-South spectroscopic redshifts. The faintest source in our sample has a magnitude m{sub AB(F098M)}= 26.9 mag. The ERS grism data also reflect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample as a function of redshift, consistent with downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes and redshifts to z {approx}> 2.

Straughn, Amber N.; Gardner, Jonathan P. [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Kuntschner, Harald; Kuemmel, Martin; Walsh, Jeremy R. [Space Telescope European Coordinating Facility, Karl Schwarzschild Str. 2, D 85748 Garching (Germany); Cohen, Seth H.; Windhorst, Rogier A.; Malhotra, Sangeeta; Rhoads, James [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); O'Connell, Robert W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Pirzkal, Norbert; Bond, Howard E. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Meurer, Gerhardt [International Centre for Radio Astronomy Research, University of Western Australia, Crawley, WA 6009 (Australia); McCarthy, Patrick J. [Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States); Hathi, Nimish P. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Balick, Bruce [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Calzetti, Daniela [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Disney, Michael J. [School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA (United Kingdom); Dopita, Michael A. [Research School of Astronomy and Astrophysics, Australian National University, ACT 2611 (Australia); Frogel, Jay A., E-mail: amber.n.straughn@nasa.gov [Association of Universities for Research in Astronomy, Washington, DC 20005 (United States)

2011-01-15

110

Early adaptive immune suppression in children with septic shock: a prospective observational study  

PubMed Central

Introduction Innate immune suppression occurs commonly in pediatric critical illness, in which it is associated with adverse outcomes. Less is known about the adaptive immune response in critically ill children with sepsis. We designed a single-center prospective, observational study to test the hypothesis that children with septic shock would have decreased adaptive immune function compared with healthy children and that among children with sepsis, lower adaptive immune function would be associated with the development of persistent infection or new nosocomial infection. Methods Children (18 years or younger) who were admitted to the pediatric intensive care unit with septic shock (by International Consensus Criteria) were enrolled in the study. Blood samples were taken within 48 hours of sepsis onset and again on Day 7 of illness. Adaptive immune function was assessed with ex vivo phytohemagglutinin (PHA)-induced cytokine production capacity of isolated CD4+ T cells. Percentage of regulatory T cells was measured with flow cytometry. Absolute lymphocyte counts were recorded when available. Results In total, 22 children with septic shock and eight healthy controls were enrolled. Compared with those from healthy children, CD4+ T cells isolated from septic shock children on Days 1 to 2 of illness and stimulated with PHA produced less of the pro-inflammatory cytokine interferon gamma (IFN-?) (P?=?0.002), and the antiinflammatory cytokines interleukin (IL)-4 (P?=?0.03) and IL-10 (P?=?0.02). Among septic shock children, those who went on to develop persistent or nosocomial infection had decreased T-cell ex vivo PHA-induced production of IFN-? (P?=?0.01), IL-2 (P?=?0.01), IL-4 (P?=?0.008), and IL-10 (P?=?0.001) compared with septic shock children who did not. Percentage of regulatory T cells (CD4+CD25+CD127lo) did not differ among groups. Conclusions Adaptive immune suppression may occur early in the course of pediatric septic shock and is associated with adverse infection-related outcomes. PMID:25005517

2014-01-01

111

Chemically Driven Spinodal Decomposition  

NASA Astrophysics Data System (ADS)

Thermally driven spinodal decomposition in polymer/polymer systems is often observed through the growth of a peak in the small-angle light scattering pattern. Phase growth is related to an increase in intensity with time following Cahn-Hillard theory. Latter stage deviations from this thermodynamic prediction are described by Oswald ripening mechanisms. A parallel to thermally driven phase separation is seen in some systems where miscibility is governed not by a thermal driving force but by a chemical reaction which leads to immiscibility of a reaction product and a polymer phase. In this study hydroxyl terminated, low molecular weight polydimethyl siloxane is reacted with multi-functional silicon based crosslinking agents to form a two phase rubber with silica-like inclusions. By varying the molecular weight of the PDMS precursor, the catalyst type and other reaction conditions the phase separation process can be drastically altered. A modified Cahn-Hillard approach is described where extent of reaction substitutes for the thermal driving force in conventional spinodal decomposition.

Sukumaran, S.; Beaucage, G.; Viers, B.; Mark, J. E.; Saraf, M.

1997-03-01

112

Early discharge of patients with pulmonary embolism: a two-phase observational study  

Microsoft Academic Search

The aim of the present study was to assess whether patients with pulmonary embolism (PE) could be managed as outpatients after early discharge from hospital using low molecular weight heparin instead of remaining as in-patients until effective oral anticoagulation was achieved. Phase 1 of the study identified criteria for the safe discharge of selected patients; phase 2 treated a cohort

C. W. H. Davies; J. Wimperis; E. S. Green; K. Pendry; J. Killen; I. Mehdi; C. Tiplady; P. Kesteven; P. Rose; W. Oldfield

2007-01-01

113

Observational Study of Early Childhood Programs. Final Report. Volume I: Life in Preschool.  

ERIC Educational Resources Information Center

This study of 119 preschool programs in 5 states was designed to describe the classroom experiences of economically or educationally disadvantaged 4-year-old children and to examine linkages between characteristics of early childhood programs and the activities of the children and teachers in the classroom. Chapters 1 and 2 describe the context…

Layzer, Jean I.; And Others

114

Early Childhood Development and School Readiness: Some Observations about "Homework" for New Century Working Parents.  

ERIC Educational Resources Information Center

This keynote address examines the relationship between early childhood development and school readiness. The address begins with basic statistical data indicative of the well-being of children in Pennsylvania and Illinois and maintains that advocacy embracing and encouraging interdisciplinary professional collaboration for supporting and…

Slaughter-Defoe, Diana T.

115

Thermal decomposition products of butyraldehyde  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

116

Erbium hydride decomposition kinetics.  

SciTech Connect

Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report are analyzed quantitatively using Redhead's method to yield kinetic parameters (E{sub A} {approx} 54.2 kcal/mol), which are then utilized to predict hydrogen outgassing in vacuum for a variety of thermal treatments. Interestingly, it was found that the activation energy for desorption can vary by more than 7 kcal/mol (0.30 eV) for seemingly similar samples. In addition, small amounts of less-stable hydrogen were observed for all erbium dihydride films. A detailed explanation of several approaches for analyzing thermal desorption spectra to obtain kinetic information is included as an appendix.

Ferrizz, Robert Matthew

2006-11-01

117

Reactive molecular dynamics simulation of solid nitromethane impact on (010) surfaces induced and nonimpact thermal decomposition.  

PubMed

Which is the first step in the decomposition process of nitromethane is a controversial issue, proton dissociation or C-N bond scission. We applied reactive force field (ReaxFF) molecular dynamics to probe the initial decomposition mechanisms of nitromethane. By comparing the impact on (010) surfaces and without impact (only heating) for nitromethane simulations, we found that proton dissociation is the first step of the pyrolysis of nitromethane, and the C-N bond decomposes in the same time scale as in impact simulations, but in the nonimpact simulation, C-N bond dissociation takes place at a later time. At the end of these simulations, a large number of clusters are formed. By analyzing the trajectories, we discussed the role of the hydrogen bond in the initial process of nitromethane decompositions, the intermediates observed in the early time of the simulations, and the formation of clusters that consisted of C-N-C-N chain/ring structures. PMID:22404203

Guo, Feng; Cheng, Xin-lu; Zhang, Hong

2012-04-12

118

Color distributions in early-type galaxies. I. BVRI observations with a scanning CCD  

Microsoft Academic Search

An RCA CCD has been used in a scanning mode on the Palomar 1.5-m telescope to obtain high precision photometric images of three early-type galaxies. Advantages of this mode of operation include much reduced pixel-to-pixel sensitivity variations and more accurate sky subtraction. Frames in B, V, R, and I of NGC 4486 (M87) have been used to show, by comparison

T. A. Boroson; I. B. Thompson; S. A. Shectman

1983-01-01

119

Color distributions in early-type galaxies. I - BVRI observations with a scanning CCD  

Microsoft Academic Search

An RCA CCD has been used in a scanning mode on the Palomar 1.5-m telescope to obtain high precision photometric images of three early-type galaxies. Advantages of this mode of operation include much reduced pixel-to-pixel sensitivity variations and more accurate sky subtraction. Frames in B, V, R, and I of NGC 4486 (M87) have been used to show, by comparison

T. A. Boroson; I. B. Thompson; S. A. Shectman

1983-01-01

120

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

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

121

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

E-print Network

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.

R. Y. Chiao

2006-06-28

122

Impulsivity-hyperactivity and subtypes of aggression in early childhood: an observational and short-term longitudinal study  

Microsoft Academic Search

This short-term longitudinal study (N = 112) was conducted to explore the concurrent and prospective associations between teacher-reported impulsive-hyperactive\\u000a behavior and observed relational and physical aggression during early childhood (M = 45.54 months old, SD = 9.07). Multiple informants and methods including observational methods (i.e., 160 min per child)\\u000a were used to assess aggression and impulsivity-hyperactivity. All measures were found to be valid and reliable. Prospective\\u000a hierarchical regression

Jamie M. Ostrov; Stephanie A. Godleski

2009-01-01

123

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

NASA Astrophysics Data System (ADS)

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.

Kapoor, R. C.

2013-11-01

124

Time dependence of ethylene decomposition and byproducts formation in a continuous flow dielectric-packed plasma reactor.  

PubMed

This work investigated the decomposition of ethylene in a continuous flow dielectric-packed bed plasma reactor filled with various packing materials at atmospheric pressure and room temperature. When compared to the case without any packing material, the reactor filled with packing materials remarkably facilitated the plasma-induced decomposition of ethylene in the order of ?-alumina>silica>zirconia>glass wool (GW). Under identical condition, the increase in the decomposition efficiency (DE) with increasing the specific energy input was more rapid in the plasma reactor filled with the packing materials than in the blank plasma reactor. In the early stage, almost complete decomposition of ethylene was observed with the ?-alumina, but after a certain period of time, the DE decreased with time. Unlike the ?-alumina, the other packing materials examined did not show any significant deterioration in the decomposition over time during 10-h operation. After the regeneration of the used packing materials by using the plasma in the presence of oxygen, the original decomposition performance was nearly recovered. The decrease in the BET surface area due to the formation of polymer deposits was observed in the used ?-alumina and silica; however the surface area was almost regained by the regeneration. While no other byproducts except carbon oxides and N2O were detected with the ?-alumina and silica, methane, acetylene, formaldehyde and N2O were identified in the effluent gas with the zirconia and GW packing materials. PMID:23415991

Gandhi, M Sanjeeva; Ananth, Antony; Mok, Young Sun; Song, Jun-Ik; Park, Kyu-Hyun

2013-04-01

125

Excess Optical Enhancement Observed with ARCONS for Early Crab Giant Pulses  

NASA Astrophysics Data System (ADS)

We observe an extraordinary link in the Crab pulsar between the enhancement of an optical pulse and the timing of the corresponding giant radio pulse. At optical through infrared wavelengths, our observations use the high time resolution of ARray Camera for Optical to Near-IR Spectrophotometry, a unique superconducting energy-resolving photon-counting array at the Palomar 200 inch telescope. At radio wavelengths, we observe with the Robert C. Byrd Green Bank Telescope and the Green Bank Ultimate Pulsar Processing Instrument backend. We see an 11.3% ± 2.5% increase in peak optical flux for pulses that have an accompanying giant radio pulse arriving near the peak of the optical main pulse, in contrast to a 3.2% ± 0.5% increase when an accompanying giant radio pulse arrives soon after the optical peak. We also observe that the peak of the optical main pulse is 2.8% ± 0.8% enhanced when there is a giant radio pulse accompanying the optical interpulse. We observe no statistically significant spectral differences between optical pulses accompanied by and not accompanied by giant radio pulses. Our results extend previous observations of optical-radio correlation to the time and spectral domains. Our refined temporal correlation suggests that optical and radio emission are indeed causally linked, and the lack of spectral differences suggests that the same mechanism is responsible for all optical emission.

Strader, M. J.; Johnson, M. D.; Mazin, B. A.; Spiro Jaeger, G. V.; Gwinn, C. R.; Meeker, S. R.; Szypryt, P.; van Eyken, J. C.; Marsden, D.; O'Brien, K.; Walter, A. B.; Ulbricht, G.; Stoughton, C.; Bumble, B.

2013-12-01

126

Anemia after gastrectomy for early gastric cancer: Long-term follow-up observational study  

PubMed Central

AIM: To identify the incidence and etiology of anemia after gastrectomy in patients with long-term follow-up after gastrectomy for early gastric cancer. METHODS: The medical records of those patients with early gastric adenocarcinoma who underwent curative gastrectomy between January 2006 and October 2007 were reviewed. Patients with anemia in the preoperative workup, cancer recurrence, undergoing systemic chemotherapy, with other medical conditions that can cause anemia, or treated during follow up with red cell transfusions or supplements for anemia were excluded. Anemia was defined by World Health Organization criteria (Hb < 12 g/dL in women and < 13 g/dL in men). Iron deficiency was defined as serum ferritin < 20 ?g/dL. Vitamin B12 deficiency was defined as serum vitamin B12 < 200 pg/mL. Iron deficiency anemia was defined as anemia with concomitant iron deficiency. Anemia from vitamin B12 deficiency was defined as megaloblastic anemia (mean cell volume > 100 fL) with vitamin B12 deficiency. The profile of anemia over 48 mo of follow-up was analyzed. RESULTS: One hundred sixty-one patients with gastrectomy for early gastric cancer were analyzed. The incidence of anemia was 24.5% at 3 mo after surgery and increased up to 37.1% at 48 mo after surgery. The incidence of iron deficiency anemia increased during the follow up and became the major cause of anemia at 48 mo after surgery. Anemia of chronic disease and megaloblastic anemia were uncommon. The incidence of anemia in female patients was significantly higher than in male patients at 12 (40.0% vs 22.0%, P = 0.033), 24 (45.0% vs 25.0%, P = 0.023), 36 (55.0% vs 28.0%, P = 0.004), and 48 mo (52.0% vs 31.0%, P = 0.022) after surgery. Patients with total gastrectomy showed significantly higher incidence of anemia than patients with subtotal gastrectomy at 48 mo after surgery (60.7% vs 31.3%, P = 0.008). The incidence of iron deficiency was significantly higher in female patients than in male patients at 6 (35.4% vs 13.3%, P = 0.002), 12 (45.8% vs 16.8%, P < 0.001), 18 (52.1% vs 22.3%, P < 0.001), 24 (60.4% vs 20.9%, P < 0.001), 36 (62.5% vs 29.2%, P < 0.001), and 48 mo (66.7% vs 34.7%, P = 0.001) after surgery. CONCLUSION: Anemia was frequent after gastrectomy for early gastric cancer, with iron deficiency being the major cause. Evaluation for anemia including iron status should be performed after gastrectomy and appropriate iron replacement should be considered. PMID:23155340

Lim, Chul-Hyun; Kim, Sang Woo; Kim, Won Chul; Kim, Jin Soo; Cho, Yu Kyung; Park, Jae Myung; Lee, In Seok; Choi, Myung-Gyu; Song, Kyo-Young; Jeon, Hae Myung; Park, Cho-Hyun

2012-01-01

127

Ultra-Fast Flash Observatory (uffo) for Observation of Early Photons from Gamma Ray Bursts  

NASA Astrophysics Data System (ADS)

One of the least documented and understood aspects of gamma-ray bursts (GRB) is the rise phase of the optical light curve. The Ultra-Fast Flash Observatory (UFFO) is an effort to address this question through extraordinary opportunities presented by a series of space missions including a small spacecraft observatory. The UFFO is equipped with a fast-response Slewing Mirror Telescope (SMT) which uses rapidly moving mirror or mirror arrays to redirect the optical beam rather than slewing the entire spacecraft to aim the optical instrument at the GRB position. The UFFO will probe the early optical rise of GRBs with a sub-second response, for the first time, opening a completely new frontier in GRB and transient studies, the only GRB system which can point and measure on these time scales. Its fast response measurements of the optical emission of dozens of GRB each year will provide unique probes of the burst mechanism, shock breakouts in core-collapse supernovae, tidal disruptions around black holes, test Lorentz violation, be the electromagnetic counterpart to neutrino and gravitational wave signatures of the violent universe, and verify the prospect of GRB as a new standard candle potentially opening up the z>10 universe. As a first step, we employ a motorized slewing stage in SMT which can point to the event within 1s after X-ray trigger, in the UFFO-pathfinder payload onboard the Lomonosov satellite to be launched in 2012. The pathfinder was a small and limited, yet remarkably powerful micro-observatory for rapid optical response to bright gamma-ray bursts, the first part of our GRB and rapid-response long-term program. We describe the early photon science, the space mission of UFFO-pathfinder, and our plan for the next step.

Park, I. H.; Ahmad, S.; Barrillon, P.; Brandt, S.; Budtz-Jorgensen, C.; Castro-Tirado, A. J.; Chen, P.; Choi, Y. J.; Connell, P.; Dagoret-Campagne, S.; Eyles, C.; Grossan, B.; Huang, M.-H. A.; Jung, A.; Jeong, S.; Kim, J. E.; Kim, M. B.; Kim, S.-W.; Kim, Y. W.; Krasnov, A. S.; Lee1, J.; Lim, H.; Linder, E. V.; Liu, T.-C.; Lund, N.; Min, K. W.; Na, G. W.; Nam, J. W.; Panasyuk, M. I.; Ripa, J.; Reglero, V.; Rodrigo, J. M.; Smoot, G. F.; Suh, J. E.; Svertilov, S.; Vedenkin, N.; Wang, M.-Z.; Yashin, I.

2013-12-01

128

Potential of tsunami observations in ultra long period seismic data and in infrasound data for early warning  

NASA Astrophysics Data System (ADS)

Tsunamis waves caused by the great Andaman earthquake have been observed in seismic data at Ocean Island or coastal stations up to 80 km inland. They are visible on the horizontal components in the period greater than 1000 sec. They are thought to be caused by tilts of the surface due to the tsunami loading. The displacement of the water column above the epicenter also generated infrasound waves in the period range of 300 to 600 sec which have been observed at a number of infrasound arrays around the Indian Ocean. We have also succeeded in observing these infrasound signal on the horizontal components of seismic stations. The speed of the tsunami wave in deep water is near 260 m/s whereas the speed of the infrasound wave is near 330 m/sec. We discuss the potential of using this difference for tsunami early warning. Our results open the possibility to use the existing global seismic network for direct observations of tsunamis and of infrasound signals caused by tsunamis. This is a new promising option in tsunami early warning.

Raveloson, A.; Kind, R.; Yuan, X.; Ceranna, L.

2009-12-01

129

GRANAT/SIGMA Observation of the Early Afterglow from GRB 920723 in Soft $\\gamma$-Rays  

E-print Network

We present a GRANAT/SIGMA observation of the soft gamma-ray afterglow immediately after GRB 920723. The main burst is very bright. After ~6 s, the burst light curve makes a smooth transition into an afterglow where flux decays as t^{-0.7}. The power-law decay lasts for at least 1000 s; beyond this time, the afterglow emission is lost in the background fluctuations. At least ~20% of main burst energy is emitted in the afterglow. At approximately ~6 s after the trigger, we also observe an abrupt change in the burst spectrum. At t<6 s, the ratio of 8-20 and 75-200 keV fluxes corresponds to the power law spectral index at this level afterwards. The observed afterglow characteristics are discussed in connection with the relativistic fireball model of gamma-ray bursts.

Burenin, R A; Gilfanov, M R; Terekhov, O V; Tkachenko, A V; Sazonov, S Y; Churazov, E M; Sunyaev, R A; Goldoni, P; Claret, A; Goldwurm, A; Paul, J; Roques, J P; Jourdain, E; Peláez, F; Vedrenne, G

1999-01-01

130

Let's enjoy observing early universe in the 8-m class telescope era  

NASA Astrophysics Data System (ADS)

We give a brief story on our discovery of a Lyman ? emitter at redshift 5.7. Our discovery is based on data collected at the Subaru telescope and Keck II telescope. Our observations started on 2002 February 14 and ended 2002 March 14. You may enjoy an exciting story on what we did in this month.

Fukushi, Hinako; Yoneda, Mizuki; Fujiwara, Hideaki

2003-01-01

131

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

Microsoft Academic Search

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

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

1996-01-01

132

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

ERIC Educational Resources Information Center

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…

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

2012-01-01

133

Discovery of the optical counterpart and early optical observations of GRB990712  

E-print Network

We present the discovery observations of the optical counterpart of the gamma-ray burster GRB990712 taken 4.16 hours after the outburst and discuss its light curve observed in the V, R and I bands during the first ~35 days after the outburst. The observed light curves were fitted with a power-law decay for the optical transient (OT), plus an additional component which was treated in two different ways. First, the additional component was assumed to be an underlying galaxy of constant brightness. The resulting slope of the decay is 0.97+/-0.05 and the magnitudes of the underlying galaxy are: V = 22.3 +/- 0.05, R = 21.75 +/- 0.05 and I = 21.35 +/- 0.05. Second, the additional component was assumed to be a galaxy plus an underlying supernova with a time-variable brightness identical to that of GRB980425, appropriately scaled to the redshift of GRB990712. The resulting slope of the decay is similar, but the goodness-of-fit is worse which would imply that either this GRB is not associated with an underlying supernova or the underlying supernova is much fainter than the supernova associated with GRB980425. The galaxy in this case is fainter: V = 22.7 +/- 0.05, R = 22.25 +/- 0.05 and I = 22.15 +/- 0.05; and the OT plus the underlying supernova at a given time is brighter. Measurements of the brightnesses of the OT and the galaxy by late-time HST observation and ground-based observations can thus assess the presence of an underlying supernova.

Kailash C. Sahu

2000-03-24

134

Integrating observation and statistical forecasts over sub-Saharan Africa to support Famine Early Warning  

USGS Publications Warehouse

Famine early warning in Africa presents unique challenges and rewards. Hydrologic extremes must be tracked and anticipated over complex and changing climate regimes. The successful anticipation and interpretation of hydrologic shocks can initiate effective government response, saving lives and softening the impacts of droughts and floods. While both monitoring and forecast technologies continue to advance, discontinuities between monitoring and forecast systems inhibit effective decision making. Monitoring systems typically rely on high resolution satellite remote-sensed normalized difference vegetation index (NDVI) and rainfall imagery. Forecast systems provide information on a variety of scales and formats. Non-meteorologists are often unable or unwilling to connect the dots between these disparate sources of information. To mitigate these problem researchers at UCSB's Climate Hazard Group, NASA GIMMS and USGS/EROS are implementing a NASA-funded integrated decision support system that combines the monitoring of precipitation and NDVI with statistical one-to-three month forecasts. We present the monitoring/forecast system, assess its accuracy, and demonstrate its application in food insecure sub-Saharan Africa.

Funk, C.; Verdin, J.P.; Husak, G.

2007-01-01

135

Copernicus observations of the N v resonance doublet in 53 early-type stars  

NASA Technical Reports Server (NTRS)

UV spectra in the wavelength interval 1170-1270 A are presented for 53 early-type stars ranging in spectral type from O6.5 V to B2.5 IV. The sample includes four Wolf-Rayet stars, seven known Oe-Be stars, and six galactic halo OB stars. A qualitative analysis of the stellar N v doublet reveals that: (1) N v is present in all stars hotter and more luminous than type B0 for the main sequence, B1 for giants, and B2 for supergiants; (2) shell components of N v and an unidentified absorption feature at 1230 A are present in about half of the stars; (3) the column density of N v is well correlated with bolometric luminosity over the spectral range O6 to B2; and (4) the ratio of emission to absorption equivalent width is a factor of 2 smaller in the main sequence stars than in supergiants, which suggests that the wind structure changes as a star evolves. For several stars, this ratio is too small to be explained by traditional wind models.

Abbott, D. C.; Bohlin, R. C.; Savage, B. D.

1982-01-01

136

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

NASA Astrophysics Data System (ADS)

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.

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

137

Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C454.3  

SciTech Connect

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 (LAT), covering 2008 July 7-October 6, indicate strong, highly variable {gamma}-ray emission with an average flux of {approx} 3 x 10{sup -6} photons cm{sup -2} s{sup -1}, for energies > 100 MeV. The {gamma}-ray flux is variable, with strong, distinct, symmetrically-shaped flares for which the flux increases by a factor of several on a time scale of about three days. This variability indicates a compact emission region, and the requirement that the source is optically thin to pair-production implies relativistic beaming with Doppler factor {delta} > 8, consistent with the values inferred from VLBI observations of superluminal expansion ({delta} {approx} 25). The observed {gamma}-ray spectrum is not consistent with a simple power-law, but instead steepens strongly above {approx} 2 GeV, and is well described by a broken power-law with photon indices of {approx} 2.3 and {approx} 3.5 below and above the break, respectively. This is the first direct observation of a break in the spectrum of a high luminosity blazar above 100 MeV, and it is likely direct evidence for an intrinsic break in the energy distribution of the radiating particles. Alternatively, the spectral softening above 2GeV could be due to -ray absorption via photonphoton pair production on the soft X-ray photon field of the host AGN, but such an interpretation would require the dissipation region to be located very close ({approx}< 100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

Abdo, A

2009-05-07

138

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

Microsoft Academic Search

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,

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

2012-01-01

139

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

PubMed

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

Pomata, Gianna

2011-01-01

140

The early development of object knowledge: a study of infants' visual anticipations during action observation.  

PubMed

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 incorrect target location (e.g., cup to mouth, phone to ear vs. cup to ear, brush to mouth). When observing the action sequences, infants as well as adults showed anticipatory fixations to the target areas of the displayed actions. For all infant age-groups, there were differences in anticipation frequency between functional and nonfunctional object-target combinations. Adults exhibited no effect of object-target combination, possibly because they quickly learned and flexibly anticipated the target area of observed actions, even when they watched objects being brought to incorrect target areas. Infants, however, had difficulties anticipating to incorrect target locations for familiar objects. Together, these findings suggest that by 6 months of age, infants have acquired solid knowledge about objects and the actions associated with them. PMID:20210504

Hunnius, Sabine; Bekkering, Harold

2010-03-01

141

GRANAT/SIGMA Observation of the Early Afterglow from GRB 920723 in Soft Gamma-Rays  

E-print Network

We present a GRANAT/SIGMA observation of the soft gamma-ray afterglow immediately after GRB 920723. The main burst is very bright. After ~6 s, the burst light curve makes a smooth transition into an afterglow where flux decays as t^{-0.7}. The power-law decay lasts for at least 1000 s; beyond this time, the afterglow emission is lost in the background fluctuations. At least ~20% of main burst energy is emitted in the afterglow. At approximately ~6 s after the trigger, we also observe an abrupt change in the burst spectrum. At t<6 s, the ratio of 8-20 and 75-200 keV fluxes corresponds to the power law spectral index \\alpha=0.0-0.3. At t=6 s, the value of \\alpha increases to \\alpha= ~1 and stays at this level afterwards. The observed afterglow characteristics are discussed in connection with the relativistic fireball model of gamma-ray bursts.

R. A. Burenin; A. A. Vikhlinin; M. R. Gilfanov; O. V. Terekhov; A. Yu. Tkachenko; S. Yu. Sazonov; E. M. Churazov; R. A. Sunyaev; P. Goldoni; A. Claret; A. Goldwurm; J. Paul; J. P. Roques; E. Jourdain; F. Pelaez; G. Vedrenne

1999-02-01

142

White noise from dark matter: 21 cm observations of early baryon collapse  

SciTech Connect

In concordance cosmology, dark matter density perturbations generated by inflation lead to nonlinear, virialized minihalos, into which baryons collapse at redshift z{approx}20. We survey here novel baryon evolution produced by a modification of the power spectrum from white noise density perturbations at scales below k{approx}10h Mpc{sup -1} (the smallest scales currently measured with the Lyman-{alpha} forest). Exotic dark matter dynamics, such as would arise from scalar dark matter with a late phase transition (similar to an axion, but with lower mass), or primordial black hole dark matter, create such an amplification of small scale power. The dark matter produced in such a phase transition collapses into minihalos, with a size given by the dark matter mass within the horizon at the phase transition. If the mass of the initial minihalos is larger than {approx}10{sup -3}M{sub {center_dot}}, the modified power spectrum is found to cause widespread baryon collapse earlier than standard {lambda}CDM, leading to earlier gas heating. It also results in higher spin temperature of the baryons in the 21 cm line relative to {lambda}CDM at redshifts z>20 if the mass of the minihalo is larger than 1M{sub {center_dot}}. It is estimated that experiments probing 21 cm radiation at high redshift will contribute a significant constraint on dark matter models of this type for initial minihalos larger than {approx}10M{sub {center_dot}}. These experiments may also detect (or rule out) primordial black holes as the dark matter in the window 30M{sub {center_dot}} < or approx. M{sub H} < or approx. 4x10{sup 3}M{sub {center_dot}} still left open by strong microlensing experiments and other astrophysical constraints. Early experiments reaching to z{approx_equal}15 will constrain minihalos down to {approx}10{sup 3}M{sub {center_dot}}.

Zurek, Kathryn M.; Hogan, Craig J. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Departments of Physics and Astronomy, University of Washington, Seattle, Washington 98195 (United States)

2007-09-15

143

AN OBSERVATIONAL DETERMINATION OF THE PROTON TO ELECTRON MASS RATIO IN THE EARLY UNIVERSE  

SciTech Connect

In an effort to resolve the discrepancy between two measurements of the fundamental constant mu, the proton to electron mass ratio, at early times in the universe we reanalyze the same data used in the earlier studies. Our analysis of the molecular hydrogen absorption lines in archival Very Large Telescope/Ultraviolet and Visible Echelle Spectrometer (UVES) spectra of the damped Lyman alpha systems in the quasi-stellar objects Q0347-383 and Q0405-443 yields a combined measurement of a DELTAmu/mu value of (-7 +- 8) x 10{sup -6}, consistent with no change in the value of mu over a time span of 11.5 Gyr. Here, we define DELTAmu as (mu {sub z} - mu{sub 0}) where mu {sub z} is the value of mu at a redshift of z and mu{sub 0} is the present-day value. Our null result is consistent with the recent measurements of King et al., DELTAmu/mu = (2.6 +- 3.0) x 10{sup -6}, and inconsistent with the positive detection of a change in mu by Reinhold et al. Both of the previous studies and this study are based on the same data but with differing analysis methods. Improvements in the wavelength calibration over the UVES pipeline calibration is a key element in both of the null results. This leads to the conclusion that the fundamental constant mu is unchanged to an accuracy of 10{sup -5} over the last 80% of the age of the universe, well into the matter dominated epoch. This limit provides constraints on models of dark energy that invoke rolling scalar fields and also limits the parameter space of supersymmetric or string theory models of physics. New instruments, both planned and under construction, will provide opportunities to greatly improve the accuracy of these measurements.

Thompson, Rodger I.; Bechtold, Jill; Eisenstein, Daniel; Fan, Xiaohui; Kennicutt, Robert C.; Shirley, Yancey L. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Black, John H. [Onsala Space Observatory, Chalmers University of Technology, SE-43992 Onsala (Sweden); Martins, Carlos [Centro de AstrofIsica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Prochaska, J. Xavier, E-mail: rit@email.arizona.ed, E-mail: jbechtold@as.arizona.ed, E-mail: deisenstein@as.arizona.ed, E-mail: fan@as.arizona.ed, E-mail: yshirley@as.arizona.ed, E-mail: John.Black@chalmers.s, E-mail: robk@ast.cam.ac.u, E-mail: C.J.A.P.Martins@damtp.cam.ac.u, E-mail: xavier@ucolick.or [Lick Observatory and University of California Santa Cruz, Santa Cruz, CA 95064 (United States)

2009-10-01

144

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

145

Pacing Early Mars fluvial activity at Aeolis Dorsa: Implications for Mars Science Laboratory observations at Gale Crater and Aeolis Mons  

E-print Network

The impactor flux early in Mars history was much higher than today, so sedimentary sequences include many buried craters. In combination with models for the impactor flux, observations of the number of buried craters can constrain sedimentation rates. Using the frequency of crater-river interactions, we find net sedimentation rate \\lesssim 20-300 {\\mu}m/yr at Aeolis Dorsa. This sets a lower bound of 1-15 Myr on the total interval spanned by fluvial activity around the Noachian-Hesperian transition. We predict that Gale Crater's mound (Aeolis Mons) took at least 10-100 Myr to accumulate, which is testable by the Mars Science Laboratory.

Kite, Edwin S; Fassett, Caleb I

2012-01-01

146

Thermal Decomposition Mechanism of Butyraldehyde  

NASA Astrophysics Data System (ADS)

The thermal decomposition of butyraldehyde, CH_3CH_2CH_2C(O)H, has been studied in a resistively heated SiC tubular reactor. Products of pyrolysis were identified via matrix-isolation FTIR spectroscopy and photoionization mass spectrometry in separate experiments. Carbon monoxide, ethene, acetylene, water and ethylketene were among the products detected. To unravel the mechanism of decomposition, pyrolysis of a partially deuterated sample of butyraldehyde was studied. Also, the concentration of butyraldehyde in the carrier gas was varied in experiments to determine the presence of bimolecular reactions. The results of these experiments can be compared to the dissociation pathways observed in similar aldehydes and are relevant to the processing of biomass, foods, and tobacco.

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

2013-06-01

147

Early Prediction of Intensive Care Unit-Acquired Weakness Using Easily Available Parameters: A Prospective Observational Study  

PubMed Central

Introduction An early diagnosis of Intensive Care Unit–acquired weakness (ICU–AW) using muscle strength assessment is not possible in most critically ill patients. We hypothesized that development of ICU–AW can be predicted reliably two days after ICU admission, using patient characteristics, early available clinical parameters, laboratory results and use of medication as parameters. Methods Newly admitted ICU patients mechanically ventilated ?2 days were included in this prospective observational cohort study. Manual muscle strength was measured according to the Medical Research Council (MRC) scale, when patients were awake and attentive. ICU–AW was defined as an average MRC score <4. A prediction model was developed by selecting predictors from an a–priori defined set of candidate predictors, based on known risk factors. Discriminative performance of the prediction model was evaluated, validated internally and compared to the APACHE IV and SOFA score. Results Of 212 included patients, 103 developed ICU–AW. Highest lactate levels, treatment with any aminoglycoside in the first two days after admission and age were selected as predictors. The area under the receiver operating characteristic curve of the prediction model was 0.71 after internal validation. The new prediction model improved discrimination compared to the APACHE IV and the SOFA score. Conclusion The new early prediction model for ICU–AW using a set of 3 easily available parameters has fair discriminative performance. This model needs external validation. PMID:25347675

Wieske, Luuk; Witteveen, Esther; Verhamme, Camiel; Dettling-Ihnenfeldt, Daniela S.; van der Schaaf, Marike; Schultz, Marcus J.; van Schaik, Ivo N.; Horn, Janneke

2014-01-01

148

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

USGS Publications Warehouse

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.

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

149

Infrared observations of the 2006 outburst of the recurrent nova RS Ophiuchi: the early phase  

E-print Network

We present infrared spectroscopy of the recurrent nova RS Ophiuchi, obtained 11.81, 20.75 and 55.71 days following its 2006 eruption. The spectra are dominated by hydrogen recombination lines, together with HeI, OI and OII lines; the electron temperature of ~10^4 K implied by the recombination spectrum suggests that we are seeing primarily the wind of the red giant, ionized by the ultraviolet flash when RS Oph erupted. However, strong coronal emission lines (i.e. emission from fine structure transitions in ions having high ionization potential) are present in the last spectrum. These imply a temperature of 930000K for the coronal gas; this is in line with x-ray observations of the 2006 eruption. The emission line widths decrease with time in a way that is consistent with the shock model for the x-ray emission.

Evans, A; Yang, B; Matsuoka, Y; Tsuzuki, Y; Bode, M F; Eyres, S P S; Geballe, T R; Woodward, C E; Gehrz, R D; Lynch, D K; Rudy, R J; Russell, R W; O'Brien, T J; Starrfield, S G; Davis, R J; Ness, J U; Drake, J; Osborne, J P; Page, K L; Adamson, A; Schwarz, G; Krautter, J; Yang, Bin; Ness, Jan-Uwe

2006-01-01

150

Infrared observations of the 2006 outburst of the recurrent nova RS Ophiuchi: the early phase  

E-print Network

We present infrared spectroscopy of the recurrent nova RS Ophiuchi, obtained 11.81, 20.75 and 55.71 days following its 2006 eruption. The spectra are dominated by hydrogen recombination lines, together with HeI, OI and OII lines; the electron temperature of ~10^4 K implied by the recombination spectrum suggests that we are seeing primarily the wind of the red giant, ionized by the ultraviolet flash when RS Oph erupted. However, strong coronal emission lines (i.e. emission from fine structure transitions in ions having high ionization potential) are present in the last spectrum. These imply a temperature of 930000K for the coronal gas; this is in line with x-ray observations of the 2006 eruption. The emission line widths decrease with time in a way that is consistent with the shock model for the x-ray emission.

A. Evans; T. Kerr; Bin Yang; Y. Matsuoka; Y. Tsuzuki; M. F. Bode; S. P. S. Eyres; T. R. Geballe; C. E. Woodward; R. D. Gehrz; D. K. Lynch; R. J. Rudy; R. W. Russell; T. J. O'Brien; S. G. Starrfield; R. J. Davis; Jan-Uwe Ness; J. Drake; J. P. Osborne; K. L. Page; A. Adamson; G. Schwarz; J. Krautter

2006-09-14

151

HST WFC3 Early Release Science: Emission-Line Galaxies from IR Grism Observations  

NASA Technical Reports Server (NTRS)

We present grism spectra of emission line galaxies (ELGs) from 0.6-1.6 microns from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). These new infrared grism data augment previous optical Advanced Camera for Surveys G800L (0.6-0.95 micron) grism data in GOODS South, extending the wavelength coverage well past the G800L red cutoff. The ERS grism field was observed at a depth of 2 orbits per grism, yielding spectra of hundreds of faint objects, a subset of which are presented here. ELGs are studied via the Ha, [O III ], and [OII] emission lines detected in the redshift ranges 0.2 less than or equal to z less than or equal to 1.6, 1.2 less than or equal to z less than or equal to 2.4 and 2.0 less than or equal to z less than or equal to 3.6 respectively in the G102 (0.8-1.1 microns; R approximately 210) and C141 (1.1-1.6 microns; R approximately 130) grisms. The higher spectral resolution afforded by the WFC3 grisms also reveals emission lines not detectable with the G800L grism (e.g., [S II] and [S III] lines). From these relatively shallow observations, line luminosities, star formation rates, and grism spectroscopic redshifts are determined for a total of 25 ELGs to M(sub AB)(F098M) approximately 25 mag. The faintest source in our sample with a strong but unidentified emission line--is MAB(F098M)=26.9 mag. We also detect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample, indicative of downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes.

Straughn, A. N.; Kuntschner, H.; Kuemmel, M.; Walsh, J. R.; Cohen, S. H.; Gardner, J. P.; Windhorst, R. A.; O'Connell, R. W.; Pirzkal, N.; Meurer, G.; McCarthy, P. J.; Hathi, N. P.; Malhotra, S.; Rhoads, J.; Balick, B.; Bond, H. E.; Calzetti, D.; Disney, M. J.; Dopita, M. A.; Frogel, J. A.; Hall, D. N. B.; Holtzman, J. A.; Kimlbe, R. A.; Trauger, J. T.; Young, E. T.

2010-01-01

152

Irradiation phenomena in young solar-type stars and the early solar system: X-ray observations and ?-ray constraints  

NASA Astrophysics Data System (ADS)

The high levels of X-ray flaring activity observed in young stars and protostars suggest correspondingly high levels of low-energy particle irradiation of their circumstellar disks, and hence of early solar system material like meteorites. We first briefly review the latest X-ray observational results obtained by Chandra and XMM-Newton on two 'typical' star-forming regions, Orion and ? Ophiuchi. We then discuss a new 'accretion-ejection-irradiation-transport' model for young stars which, when scaled to the X-ray fluxes, accounts simultaneously for four extinct radioactivity ratios, in particular the purely spallogenic 10Be/ 9Be ratio, and the 26Al/ 27Al ratio. We point out the importance of the environment in which nearby star formation is taking place today, namely the Gould Belt, and the possible connection between Comptel detections of 26Al ?-ray line emission from these regions, and new constraints on the origin of the solar system.

Montmerle, Thierry

2002-07-01

153

[CII] At 1 < z < 2: Observing Star Formation in the Early Universe with Zeus (1 and 2)  

NASA Technical Reports Server (NTRS)

We report the detection of the [CII] 158 micron fine structure line from six submillimeter galaxies with redshifts between 1.12 and 1.73. This more than doubles the total number of [CII] 158 micron detections reported from high redshift sources. These observations were made with the Redshift(z) and Early Universe Spectrometer(ZEUS) at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii between December 2006 and March 2009. ZEUS is a background limited submm echelle grating spectrometer (Hailey-Dunsheath 2009). Currently we are constructing ZEUS-2. This new instrument will utilize the same grating but will feature a two dimensional transition-edge sensed bolometer array with SQUID multiplexing readout system enabling simultaneous background limited observations in the 200, 340,450 and 650 micron telluric windows. ZEUS-2 will allow for long slit imaging spectroscopy in nearby galaxies and a [CII] survey from z 0.25 to 2.5.

Ferkinhoff, Carl; Hailey-Dunsheath, S.; Nikola, T.; Oberst, T.; Parshley, S.; Stacey, G.; Benford, D.; staguhn, J.

2010-01-01

154

Decomposition with Cheerios  

NSDL National Science Digital Library

The students will use Cheerios as manipulatives for decomposing numbers 5-10. Students will be encouraged to decompose numbers in as many different ways as possible. Students will also record their decompositions as addition problems.

Decloedt, Tracey

2012-07-06

155

Early Observations and Analysis of the Type Ia SN 2014J in M82  

E-print Network

We present optical and near infrared (NIR) observations of the nearby Type Ia SN 2014J. Seventeen optical and twenty-three NIR spectra were obtained from 10 days before ($-$10d) to 10 days after (+10d) the time of maximum $B$-band brightness. The relative strengths of absorption features and their patterns of development can be compared at one day intervals throughout most of this period. Carbon is not detected in the optical spectra, but we identify CI $\\lambda$ 1.0693 in the NIR spectra. We find that MgII lines with high oscillator strengths have higher initial velocities than other MgII lines. We show that the velocity differences can be explained by differences in optical depths due to oscillator strengths. The spectra of SN 2014J show it is a normal SN Ia, but many parameters are near the boundaries between normal and high-velocity subclasses. The velocities for OI, MgII, SiII, SII, CaII and FeII suggest that SN 2014J has a layered structure with little or no mixing. That result is consistent with the de...

Marion, G H; Hsiao, E Y; Banerjee, D P K; Valenti, S; Stritzinger, M D; Vinkó, J; Joshi, V; Venkataraman, V; Ashok, N M; Amanullah, R; Binzel, R P; Bochanski, J J; Bryngelson, G L; Burns, C R; Drozdov, D; Fieber-Beyer, S K; Graham, M L; Howell, D A; Johansson, J; Kirshner, R P; Milne, P A; Parrent, J; Silverman, J M; Vervack, R J; Wheeler, J C

2014-01-01

156

The performance of field scientists undertaking observations of early life fossils while in simulated space suit  

NASA Astrophysics Data System (ADS)

We conducted simulated Apollo Extravehicular Activity's (EVA) at the 3.45 Ga Australian 'Pilbara Dawn of life' (Western Australia) trail with field and non-field scientists using the University of North Dakota's NDX-1 pressurizable space suit to overview the effectiveness of scientist astronauts employing their field observation skills while looking for stromatolite fossil evidence. Off-world scientist astronauts will be faced with space suit limitations in vision, human sense perception, mobility, dexterity, the space suit fit, time limitations, and the psychological fear of death from accidents, causing physical fatigue reducing field science performance. Finding evidence of visible biosignatures for past life such as stromatolite fossils, on Mars, is a very significant discovery. Our preliminary overview trials showed that when in simulated EVAs, 25% stromatolite fossil evidence is missed with more incorrect identifications compared to ground truth surveys but providing quality characterization descriptions becomes less affected by simulated EVA limitations as the science importance of the features increases. Field scientists focused more on capturing high value characterization detail from the rock features whereas non-field scientists focused more on finding many features. We identified technologies and training to improve off-world field science performance. The data collected is also useful for NASA's "EVA performance and crew health" research program requirements but further work will be required to confirm the conclusions.

Willson, D.; Rask, J. C.; George, S. C.; de Leon, P.; Bonaccorsi, R.; Blank, J.; Slocombe, J.; Silburn, K.; Steele, H.; Gargarno, M.; McKay, C. P.

2014-01-01

157

Group on Earth Observations (GEO) Global Drought Monitor Portal: Adding Capabilities for Forecasting Hydrological Extremes and Early Warning Networking  

NASA Astrophysics Data System (ADS)

The Intergovernmental Panel on Climate Change (IPCC 2007) has suggested the hydrometeorological extremes of both drought and flooding may increase under climate change. Drought zones can grow over large tracts of continental area and are a global-scale phenomenon (Sheffield and Wood 2011). The Group on Earth Observations Global Drought Monitor Portal (GDMP) was established as a demonstration for the 5th Earth Observation Ministerial Summit in Beijing in 2010. The European Drought Observatory, the North American Drought Monitor, the Princeton University experimental African Drought Monitor, and the University College London experimental global drought monitor were made "interoperable" through installation of Open Geospatial Consortium (OGC) Web Mapping Services (WMS) on their respective servers, allowing maps of current drought conditions to be exchanged and assembled into maps of global drought coverage on the NIDIS portal. Partners from the Republic of Argentina, the Commonwealth of Australia, China, Jordan, Brazil, and Uruguay have also joined. The GEO Global Drought Monitoring, Forecasting, and Early Warning effort involves multiple parties and institutions, including the World Meteorological Organization, the World Climate Research Program Drought Interest Group, NASA, and others. The GEO Secretariat held a launch workshop in Geneva on 4-6 May 2010 to initiate drafting the final GEO Work Plan, and, during this meeting, additional capabilities were added to the existing GDMP: 1) drought forecasting was added to drought "current conditions" monitoring, in a partnership with Joint Research Centre (and other partners) aiming at a combined platform for Hydrological Extremes (drought and flooding); 2) extending drought forecasts from the medium-range 15-day window to a 30-day window; this will be tested through pilot projects over Europe and Africa, as part of the Global Water Scarcity Information Service (GLOWASIS)and the Improved Drought Early Warning Forecasting for Africa (DEWFORA) to strengthen preparedness and adaptation; 3) setting up an Early Warning System network for drought ( to be developed through World Meteorological Organization WMO); and 4) adding global remote sensing drought monitoring capabilities (soil moisture anomalies). Flooding represents positive precipitation anomalies, whereas drought represents negative precipitation anomalies. The JRC combined Hydrologic Extremes platform will include multiple models and tools, such as; 1) JRC Global Flood Detection System and Global Flood Early Warning System; 2) the WMO Flash Flood Guidance system; 3) the Dartmouth Flood Observatory; 4) a suite of monitored and forecasted drought and water scarcity indicators through the various drought observatories accessible through the GEO Global Drought Monitor Portal. The GEO Global Drought and Flooding systems represent the "applications-side" of water activities within the GEO Work Plan and are supported by the "Research and Development (R&D) side" of water activities within the new 2012-2015 GEO Work Plan.

Pozzi, W.; de Roo, A.; Vogt, J.; Lawford, R. G.; Pappenberger, F.; Heim, R. R.; Stefanski, R.

2011-12-01

158

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

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

159

Gauge- and frame-independent decomposition of nucleon spin  

SciTech Connect

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.

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

2011-01-01

160

Gauge- and frame-independent decomposition of nucleon spin  

NASA Astrophysics Data System (ADS)

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.

Wakamatsu, M.

2011-01-01

161

A Multilinear Singular Value Decomposition  

Microsoft Academic Search

We discuss a multilinear generalization of the singular value decomposition. There is a strong analogy between several properties of the matrix and the higher-order tensor decomposition; uniqueness, link with the matrix eigenvalue decomposition, first-order perturbation effects, etc., are analyzed. We investigate how tensor symmetries affect the decomposition and propose a multilinear generalization of the symmetric eigenvalue decomposition for pair-wise symmetric

Lieven De Lathauwer; Bart De Moor; Joos Vandewalle

2000-01-01

162

The C/O ratio at low metallicity: constraints on early chemical evolution from observations of Galactic halo stars  

E-print Network

We present new measurements of the abundances of carbon and oxygen derived from high-excitation C I and O I absorption lines in metal-poor halo stars, with the aim of clarifying the main sources of these two elements in the early stages of the chemical enrichment of the Galaxy. We target 15 new stars compared to our previous study, with an emphasis on additional C/O determinations in the crucial metallicity range -3in the line formation for both carbon and oxygen. The non-LTE effects are very strong at the lowest metallicities but, contrary to what has sometimes been assumed in the past due to a simplified assessment, of different degrees for the two elements. In addition, for the 28 stars with [Fe/H]in the same fashion as for the rest of our sample, giving consistent abundances for 43 halo stars in total. The new observations and n...

Fabbian, D; Asplund, M; Pettini, M; Akerman, C

2008-01-01

163

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

NASA Astrophysics Data System (ADS)

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.

Sonnenfeld, Alessandro; Nipoti, Carlo; Treu, Tommaso

2014-05-01

164

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

NASA Astrophysics Data System (ADS)

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.

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

165

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

NASA Astrophysics Data System (ADS)

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.

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.; Johns, H.; Joshi, T.; Mayes, D.; Mancini, R. C.; Nagayama, T.

2014-05-01

166

The Westerbork HI Survey of spiral and irregular galaxies III: HI observations of early-type disk galaxies  

E-print Network

We present HI observations of 68 early-type disk galaxies from the WHISP survey. They have morphological types between S0 and Sab and absolute B-band magnitudes between -14 and -22. These galaxies form the massive, high surface-brightness extreme of the disk galaxy population, few of which have been imaged in HI before. The HI properties of the galaxies in our sample span a large range; the average values of M_HI/L_B and D_HI/D_25 are comparable to the ones found in later-type spirals, but the dispersions around the mean are larger. No significant differences are found between the S0/S0a and the Sa/Sab galaxies. Our early-type disk galaxies follow the same HI mass-diameter relation as later-type spiral galaxies, but their effective HI surface densities are slightly lower than those found in later-type systems. In some galaxies, distinct rings of HI emission coincide with regions of enhanced star formation, even though the average gas densities are far below the threshold of star formation derived by Kennicutt (1989). Apparently, additional mechanisms, as yet unknown, regulate star formation at low surface densities. Many of the galaxies in our sample have lopsided gas morphologies; in most cases this can be linked to recent or ongoing interactions or merger events. Asymmetries are rare in quiescent galaxies. Kinematic lopsidedness is rare, both in interacting and isolated systems. In the appendix, we present an atlas of the HI observations: for all galaxies we show HI surface density maps, global profiles, velocity fields and radial surface density profiles.

E. Noordermeer; J. M. van der Hulst; R. Sancisi; R. A. Swaters; T. S. van Albada

2005-08-15

167

Coupling experimental data and a prototype model to probe the physical and chemical processes of 2,4-dinitroimidazole solid-phase thermal decomposition  

SciTech Connect

The time-dependent, solid-phase thermal decomposition behavior of 2,4-dinitroimidazole (2,4-DNI) has been measured utilizing simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) methods. The decomposition products consist of gaseous and non-volatile polymeric products. The temporal behavior of the gas formation rates of the identified products indicate that the overall thermal decomposition process is complex. In isothermal experiments with 2,4-DNI in the solid phase, four distinguishing features are observed: (1) elevated rates of gas formation are observed during the early stages of the decomposition, which appear to be correlated to the presence of exogenous water in the sample; (2) this is followed by a period of relatively constant rates of gas formation; (3) next, the rates of gas formation accelerate, characteristic of an autocatalytic reaction; (4) finally, the 2,4-DNI is depleted and gaseous decomposition products continue to evolve at a decreasing rate. A physicochemical and mathematical model of the decomposition of 2,4-DNI has been developed and applied to the experimental results. The first generation of this model is described in this paper. Differences between the first generation of the model and the experimental data collected under different conditions suggest refinements for the next generation of the model.

Behrens, R.; Minier, L. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Bulusu, S. [Army Armament Research, Development and Engineering Center, Dover, NJ (United States). Energetic Materials Div.

1998-12-31

168

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

NASA Technical Reports Server (NTRS)

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. A qualitative explanation for this effect can be derived from IMP observations, which show that the amplitude of the stream structure at 1 AU increased monotonically in late 1993, concurrent with major secular evolution in the corona. The reduction in period, then, amounts to a doppler shift due to the progressive overtaking of successively faster streams in the sequence. Attempts to model this process quantitatively with 1-D dynamic simulations falter on three accounts: (1) the reduction in period is overestimated, (2) the simulation predicts many more fronts surviving to 43 AU than are observed by Voyager; (3) the density variations are much too large. It is argued that inclusion of the 3-D geometry in the simulation would resolve most all these shortcomings. Using a series of calculations executed with 1-D, 2-D, and 3-D MHD models of hypothetical tilted-dipole flows, we show that: (1) the radial propagation velocities of 3-D fronts are less than those of 1-D or 2-D fronts, owing to the tilt of (and increased shearing across) the interaction surfaces hence the overtaking rate of successive streams is reduced; (2) in a tilted-dipole geometry, the reverse fronts should largely disappear from the equatorial plane by 43 AU, effectively halving the number of fronts to be observed (see companion paper on predominance of forward fronts at Voyager); and (3) the density enhancements would be much smaller than predicted by a 1-D model.

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

1995-01-01

169

Optimal domain decomposition strategies  

NASA Technical Reports Server (NTRS)

The primary interest of the authors is in the area of grid generation, in particular, optimal domain decomposition about realistic configurations. A grid generation procedure with optimal blocking strategies has been developed to generate multi-block grids for a circular-to-rectangular transition duct. The focus of this study is the domain decomposition which optimizes solution algorithm/block compatibility based on geometrical complexities as well as the physical characteristics of flow field. The progress realized in this study is summarized in this paper.

Yoon, Yonghyun; Soni, Bharat K.

1995-01-01

170

Isothermal decomposition of gamma-irradiated dysprosium acetate  

NASA Astrophysics Data System (ADS)

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.

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

171

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

SciTech Connect

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.

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

172

Unusually strong nitric oxide descent in the Arctic middle atmosphere in early 2013 as observed by Odin/SMR  

NASA Astrophysics Data System (ADS)

The middle atmosphere was affected by an exceptionally strong midwinter stratospheric sudden warming (SSW) during the Arctic winter 2012/2013. These unusual meteorological conditions led to a breakdown of the polar vortex, followed by the reformation of a strong upper stratospheric vortex associated with particularly efficient descent of air. Measurements by the submillimetre radiometer (SMR), on board the Odin satellite, show that very large amounts of nitric oxide (NO), produced by energetic particle precipitation (EPP) in the mesosphere/lower thermosphere (MLT), could thus enter the polar stratosphere in early 2013. The mechanism referring to the downward transport of EPP-generated NOx during winter is generally called the EPP indirect effect. SMR observed up to 20 times more NO in the upper stratosphere than the average NO measured at the same latitude, pressure and time during three previous winters where no mixing between mesospheric and stratospheric air was noticeable. This event turned out to be the strongest in the aeronomy-only period of SMR (2007-present). Our study is based on a comparison with the Arctic winter 2008/2009, when a similar situation was observed. This outstanding situation is the result of the combination of a relatively high geomagnetic activity and an unusually high dynamical activity, which makes this case a prime example to study the EPP impacts on the atmospheric composition.

Pérot, K.; Urban, J.; Murtagh, D. P.

2014-08-01

173

Early-type Galaxies at Intermediate Redshift Observed with Hubble Space Telescope WFC3: Perspectives on Recent Star Formation  

NASA Astrophysics Data System (ADS)

We present an analysis of the stellar populations of 102 visually selected early-type galaxies (ETGs) with spectroscopic redshifts (0.35 lsim z lsim 1.5) from observations in the Early Release Science program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We fit one- and two-component synthetic stellar models to the ETGs UV-optical-near-IR spectral energy distributions and find that a large fraction (~40%) are likely to have experienced a minor (fYC lsim 10% of stellar mass) burst of recent (tYC lsim 1 Gyr) star formation. The measured age and mass fraction of the young stellar populations do not strongly trend with measurements of galaxy morphology. We note that massive (M > 1010.5 M ?) recent star-forming ETGs appear to have larger sizes. Furthermore, high-mass, quiescent ETGs identified with likely companions populate a distinct region in the size-mass parameter space, in comparison with the distribution of massive ETGs with evidence of recent star formation (RSF). We conclude that both mechanisms of quenching star formation in disk-like ETGs and (gas-rich, minor) merger activity contribute to the formation of young stars and the size-mass evolution of intermediate redshift ETGs. The number of ETGs for which we have both HST WFC3 panchromatic (especially UV) imaging and spectroscopically confirmed redshifts is relatively small, therefore, a conclusion about the relative roles of both of these mechanisms remains an open question.

Rutkowski, Michael J.; Jeong, Hyunjin; Cohen, Seth H.; Kaviraj, Sugata; Windhorst, Rogier A.; Ryan, Russell E., Jr.; Koekemoer, Anton; Yi, Sukyoung K.; Hathi, Nimish P.; Dopita, Michael A.

2014-12-01

174

Serum Adhesion Molecule Levels as Prognostic Markers in Patients with Early Systemic Sclerosis: A Multicentre, Prospective, Observational Study  

PubMed Central

Objective To assess the utility of circulating adhesion molecule levels as a prognostic indicator of disease progression in systemic sclerosis (SSc) patients with early onset disease. Methods Ninety-two Japanese patients with early onset SSc presenting with diffuse skin sclerosis and/or interstitial lung disease were registered in a multicentre, observational study. Concentrations of intercellular adhesion molecule (ICAM) ?1, E-selectin, L-selectin, and P-selectin in serum samples from all patients were measured by enzyme-linked immunosorbent asssay (ELISA). In 39 patients, adhesion molecule levels were measured each year for four years. The ability of baseline adhesion molecule levels to predict subsequent progression and severity in clinical and laboratory features were evaluated statistically. Results At their first visit, serum levels of ICAM-1, E-selection, P-selectin were significantly elevated and serum L-selectin levels were significantly reduced in patients with SSc compared with healthy controls. Overall, serum ICAM-1 levels at each time point were significantly inversely associated with the %vital capacity (VC) of the same time and subsequent years by univariate analysis. The initial serum ICAM-1 levels were significantly inversely associated with the %VC at the fourth year by multiple regression analysis. The initial serum P-selectin levels were significantly associated with the health assessment questionnaire disability index (HAQ-DI) at the fourth year by multiple regression analysis. Initial adhesion molecule levels were not significantly associated with other clinical features including skin thickness score. Baseline adhesion molecule levels were not significantly associated with subsequent rate of change of clinical parameters. Conclusion In patients with SSc, serum levels of ICAM-1 and P-selectin may serve as prognostic indicators of respiratory dysfunction and physical disability, respectively. Further longitudinal studies of larger populations are needed to confirm these findings. PMID:24516598

Hasegawa, Minoru; Asano, Yoshihide; Endo, Hirahito; Fujimoto, Manabu; Goto, Daisuke; Ihn, Hironobu; Inoue, Katsumi; Ishikawa, Osamu; Kawaguchi, Yasushi; Kuwana, Masataka; Ogawa, Fumihide; Takahashi, Hiroki; Tanaka, Sumiaki; Sato, Shinichi; Takehara, Kazuhiko

2014-01-01

175

Thermal decomposition of condensed-phase nitromethane from molecular dynamics from ReaxFF reactive dynamics.  

PubMed

We studied the thermal decomposition and subsequent reaction of the energetic material nitromethane (CH(3)NO(2)) using molecular dynamics with ReaxFF, a first principles-based reactive force field. We characterize the chemistry of liquid and solid nitromethane at high temperatures (2000-3000 K) and density 1.97 g/cm(3) for times up to 200 ps. At T = 3000 K the first reaction in the decomposition of nitromethane is an intermolecular proton transfer leading to CH(3)NOOH and CH(2)NO(2). For lower temperatures (T = 2500 and 2000 K) the first reaction during decomposition is often an isomerization reaction involving the scission of the C-N bond the formation of a C-O bond to form methyl nitrate (CH(3)ONO). Also at very early times we observe intramolecular proton transfer events. The main product of these reactions is H(2)O which starts forming following those initiation steps. The appearance of H(2)O marks the beginning of the exothermic chemistry. Recent quantum-mechanics-based molecular dynamics simulations on the chemical reactions and time scales for decomposition of a crystalline sample heated to T = 3000 K for a few picoseconds are in excellent agreement with our results, providing an important, direct validation of ReaxFF. PMID:21542572

Han, Si-ping; van Duin, Adri C T; Goddard, William A; Strachan, Alejandro

2011-05-26

176

Identification of old tidal dwarfs near early-type galaxies from deep imaging and H I observations  

NASA Astrophysics Data System (ADS)

It has recently been proposed that the dwarf spheroidal galaxies located in the Local Group discs of satellites (DoSs) may be tidal dwarf galaxies (TDGs) born in a major merger at least 5 Gyr ago. Whether TDGs can live that long is still poorly constrained by observations. As part of deep optical and H I surveys with the Canada-France-Hawaii Telescope (CFHT) MegaCam camera and Westerbork Synthesis Radio Telescope made within the ATLAS3D project, and follow-up spectroscopic observations with the Gemini-North telescope, we have discovered old TDG candidates around several early-type galaxies. At least one of them has an oxygen abundance close to solar, as expected for a tidal origin. This confirmed pre-enriched object is located within the gigantic, but very low surface brightness, tidal tail that emanates from the elliptical galaxy, NGC 5557. An age of 4 Gyr estimated from its SED fitting makes it the oldest securely identified TDG ever found so far. We investigated the structural and gaseous properties of the TDG and of a companion located in the same collisional debris, and thus most likely of tidal origin as well. Despite several Gyr of evolution close to their parent galaxies, they kept a large gas reservoir. Their central surface brightness is low and their effective radius much larger than that of typical dwarf galaxies of the same mass. This possibly provides us with criteria to identify tidal objects which can be more easily checked than the traditional ones requiring deep spectroscopic observations. In view of the above, we discuss the survival time of TDGs and question the tidal origin of the DoSs.

Duc, Pierre-Alain; Paudel, Sanjaya; McDermid, Richard M.; Cuillandre, Jean-Charles; Serra, Paolo; Bournaud, Frédéric; Cappellari, Michele; Emsellem, Eric

2014-05-01

177

DECOMPOSITION IN FRESHWATER ECOSYSTEMS  

Microsoft Academic Search

This review examines the sources and composition of organic matter and the decomposition of particulate and dissolved organic matter (POM and DOM) in freshwater ecosystems. The main points to emerge from the review are listed below.1. Terrestrial plant material is an important source of allochthonous POM in lotlc systems.2. In lentic systems important autochthonous sources of DOM are the algae

R. D. Robarts

1986-01-01

178

Rainbow decompositions Raphael Yuster  

E-print Network

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

Yuster, Raphael

179

Monopropellant decomposition catalysts  

Microsoft Academic Search

The need for highly concentrated hydrogen peroxide solutions to fuel spacecraft propulsion systems necessitates the development of new catalytic formulations mainly based on supported manganese oxides. In order to improve the preparation of such catalysts, the thermal decomposition and the hydrothermal reduction of different permanganate precursors were studied, as well as the effect of washing on the products. The test

Charles Kappenstein; Laurence Pirault-Roy; Maurice Guérin; Tarek Wahdan; Asma A Ali; Fakhreia A Al-Sagheer; Mohamed I Zaki

2002-01-01

180

ChemTeacher: Decomposition Reactions  

NSDL National Science Digital Library

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.

2011-01-01

181

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

PubMed

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

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

2008-09-01

182

Color image decomposition and restoration  

Microsoft Academic Search

Meyer has recently introduced an image decomposition model to split an image into two components: a geometrical component and a texture (oscillatory) component. Inspired by his work, numerical models have been developed to carry out the decomposition of gray scale images. In this paper, we propose a decomposition algorithm for color images. We introduce a generaliza- tion of Meyers G

Jean-françois Aujol; Sung Ha Kang

2006-01-01

183

Variation of Soil Mycoflora in Decomposition of Rice Stubble from Rice-wheat Cropping System.  

PubMed

The colonization pattern and extent of decay produced in paddy stubble by soil inhabiting mycoflora were done by using nylon net bag technique. Among the three methods used for isolation of fungi, dilution plate technique recorded the highest number of fungi followed by damp chamber and direct observation method. Nutrient availability and climatic conditions (temperature, humidity and rainfall) influenced the occurrence and colonization pattern of fungi. Maximum fungal population was recorded in October (48.99 × 10(4)/g dry litter) and minimum in May (11.41 × 10(4)/g dry litter). Distribution of Deuteromycetous fungi was more in comparison to Zygomycetes, oomycetes and ascomycetes. In the early stage of decomposition Mucor racemosus, Rhizopus nigricans, Chaetomium globosum and Gliocladium species were found primarly whereas at later stages of decomposition preponderance of Aspergillus candidus, Torula graminis, Cladosporiun cladosporioides and Aspergillus luchuensis was recorded. PMID:24015096

Vibha; Sinha, Asha

2007-12-01

184

UV-DROPOUT GALAXIES IN THE GOODS-SOUTH FIELD FROM WFC3 EARLY RELEASE SCIENCE OBSERVATIONS  

SciTech Connect

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 {approx_equal} 1-3. These new HST/WFC3 observations were taken over 50 arcmin{sup 2} 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 three 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 {approx_equal} 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: (1) these WFC3 UVIS filters are very reliable in selecting LBGs with z {approx_equal} 2.0, which helps to reduce the gap between the well-studied z {approx}> 3 and z {approx} 0 regimes; (2) the combined number counts with average redshift z {approx_equal} 2.2 agree very well with the observed change in the surface densities as a function of redshift when compared with the higher redshift LBG samples; and (3) the best-fit Schechter function parameters from the rest-frame UV luminosity functions at three different redshifts fit very well with the evolutionary trend of the characteristic absolute magnitude, M*, and the faint-end slope, {alpha}, as a function of redshift. This is the first study to illustrate the usefulness of the WFC3 UVIS channel observations to select z {approx}< 3 LBGs. The addition of the new WFC3 on the HST has made it possible to uniformly select LBGs from z {approx_equal} 1 to z {approx_equal} 9 and significantly enhance our understanding of these galaxies using HST sensitivity and resolution.

Hathi, N. P. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Ryan, R. E. [Department of Physics and Astronomy, University of California, Davis, CA 92616 (United States); Cohen, S. H.; Windhorst, R. A.; Rutkowski, M. J. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Yan, H. [Center for Cosmology and AstroParticle Physics, Ohio State University, Columbus, OH 43210 (United States); McCarthy, P. J. [Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States); O'Connell, R. W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Koekemoer, A. M.; Bond, H. E. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Disney, M. J. [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, ACT 2611 (Australia); Frogel, Jay A. [Association of Universities for Research in Astronomy, Washington, DC 20005 (United States); Hall, D. N. B. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Holtzman, J. A. [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Kimble, R. A. [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Paresce, F. [Istituto di Astrofisica Spaziale e Fisica Cosmica, INAF, Via Gobetti 101, 40129 Bologna (Italy); Saha, A., E-mail: Nimish.Hathi@ucr.ed [National Optical Astronomy Observatories, Tucson, AZ 85726-6732 (United States)

2010-09-10

185

ELEMENTAL ABUNDANCES IN THE X-RAY GAS OF EARLY-TYPE GALAXIES WITH XMM-NEWTON AND CHANDRA OBSERVATIONS  

SciTech Connect

The source of hot gas in elliptical galaxies is thought to be due to stellar mass loss, with contributions from supernova (SN) events and possibly from infall from a surrounding environment. This picture predicts supersolar values for the metallicity of the gas toward the inner part of the galaxy, which can be tested by measuring the gas phase abundances. We use high-quality data for 10 nearby early-type galaxy from XMM-Newton, featuring both the European Photon Imaging Camera and the Reflection Grating Spectrometer, where the strongest emission lines are detected with little blending; some Chandra data are also used. We find excellent consistency in the elemental abundances between the different XMM-Newton instruments and good consistency with Chandra. Differences in abundances with aperture size and model complexity are examined, but large differences rarely occur. For a two-temperature thermal model plus a point source contribution, the median Fe and O abundances are 0.86 and 0.44 of the solar value, while Si and Mg abundances are similar to that for Fe. This is similar to stellar abundances for these galaxies but SNe were expected to enhance the gas phase abundances considerably, which is not observed.

Ji Jun; Irwin, Jimmy A.; Athey, Alex; Bregman, Joel N.; Lloyd-Davies, Edward J. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States)], E-mail: jijun@umich.edu, E-mail: jairwin@umich.edu, E-mail: athey@arlut.utexas.edu, E-mail: jbregman@umich.edu, E-mail: radix@freeshell.org

2009-05-10

186

Sliding Empirical Mode Decomposition  

Microsoft Academic Search

Biomedical signals are in general non-linear and non-stationary which renders them difficult to analyze with classical time series analysis techniques. Empirical Mode Decomposition (EMD) in conjunction with a Hilbert spectral transform, together called Hilbert-Huang Transform, is ideally suited to extract informative components which are characteristic of underlying biological or physiological processes. The method is fully adaptive and generates a complete

R. Faltermeier; A. Zeiler; I. R. Keck; A. M. Tome; A. Brawanski; E. W. Lang

2010-01-01

187

THE EFFECTS OF REACTOR IRRADIATION UPON THE SUBSEQUENT THERMAL DECOMPOSITION OF LEAD STYPHNATE  

Microsoft Academic Search

The kinetics of the thermal decomposition of lead styphnate were ; examined after being subjected to a series of irradiations in the graphite ; reactor. It was observed that the decomposition rate is enhanced and the ; activation energy for at least part of the decomposition is significantly ; decreased by nuclear irradiation. It also was found that it did

Ted B. Flanagan

1962-01-01

188

Multicriteria approximation through decomposition  

SciTech Connect

The authors propose a general technique called solution decomposition to devise approximation algorithms with provable performance guarantees. The technique is applicable to a large class of combinatorial optimization problems that can be formulated as integer linear programs. Two key ingredients of the technique involve finding a decomposition of a fractional solution into a convex combination of feasible integral solutions and devising generic approximation algorithms based on calls to such decompositions as oracles. The technique is closely related to randomized rounding. The method yields as corollaries unified solutions to a number of well studied problems and it provides the first approximation algorithms with provable guarantees for a number of new problems. The particular results obtained in this paper include the following: (1) The authors demonstrate how the technique can be used to provide more understanding of previous results and new algorithms for classical problems such as Multicriteria Spanning Trees, and Suitcase Packing. (2) They show how the ideas can be extended to apply to multicriteria optimization problems, in which they wish to minimize a certain objective function subject to one or more budget constraints. As corollaries they obtain first non-trivial multicriteria approximation algorithms for problems including the k-Hurdle and the Network Inhibition problems.

Burch, C. [Carnegie Mellon Univ., Pittsburgh, PA (United States). School of Computer Sciences]|[Sandia National Labs., Albuquerque, NM (United States); Krumke, S. [Univ. of Wuerzburg (Germany). Dept. of Computer Science; Marathe, M. [Los Alamos National Lab., NM (United States); Phillips, C. [Sandia National Labs., Albuquerque, NM (United States). Applied Mathematics Dept.; Sundberg, E. [Rutgers Univ., NJ (United States). Dept. of Computer Science]|[Sandia National Labs., Albuquerque, NM (United States)

1997-12-01

189

Multicriteria approximation through decomposition  

SciTech Connect

The authors propose a general technique called solution decomposition to devise approximation algorithms with provable performance guarantees. The technique is applicable to a large class of combinatorial optimization problems that can be formulated as integer linear programs. Two key ingredients of their technique involve finding a decomposition of a fractional solution into a convex combination of feasible integral solutions and devising generic approximation algorithms based on calls to such decompositions as oracles. The technique is closely related to randomized rounding. Their method yields as corollaries unified solutions to a number of well studied problems and it provides the first approximation algorithms with provable guarantees for a number of new problems. The particular results obtained in this paper include the following: (1) the authors demonstrate how the technique can be used to provide more understanding of previous results and new algorithms for classical problems such as Multicriteria Spanning Trees, and Suitcase Packing; (2) they also show how the ideas can be extended to apply to multicriteria optimization problems, in which they wish to minimize a certain objective function subject to one or more budget constraints. As corollaries they obtain first non-trivial multicriteria approximation algorithms for problems including the k-Hurdle and the Network Inhibition problems.

Burch, C. [Carnegie Mellon Univ., Pittsburgh, PA (United States). School of Computer Science; Krumke, S. [Univ. of Wuerzburg (Germany). Dept. of Computer Science; Marathe, M. [Los Alamos National Lab., NM (United States); Phillips, C. [Sandia National Labs., Albuquerque, NM (United States). Applied Mathematics Dept.; Sundberg, E. [Rutgers Univ., NJ (United States). Dept. of Computer Science

1998-06-01

190

The Development of the Problem Decomposition Diagnostic  

NSDL National Science Digital Library

The Problem Decomposition Diagnostic is a testing instrument designed to help determine student ability in two areas of problem solving. As the name implies, all versions of the test have been intended to gauge student ability to decompose, or break up, complex physics problems into simpler sub-problems. Additionally, later versions of the PDD sought to also examine the strategy the student would use to solve such subproblems. This thesis is organized in a roughly chronological manner, following the development of the Problem Decomposition Diagnostic from early open response tests and interview tasks to the current multiple-choice format instrument. Both qualitative and quantitative methods were used in developing this instrument and measuring its validity. Extensive appendices include every version of the test, plus a complete laboratory course which helped inspire this work and informed a number of the aspects of the PDD.

Van Domelen, David

2007-01-01

191

Observed Differences between Early Childhood Programs in the U.S. and Korea: Reflections of "Developmentally Appropriate Practices" in Two Cultural Contexts  

ERIC Educational Resources Information Center

Ninety children from South Korea and 119 children from the United States were observed in early childhood programs, and differences in classroom environments and teachers' and children's behavior in the two countries were identified. In both countries, there was evidence that preschool education is guided by ideas about "developmentally…

Clarke-Stewart, K. Alison; Lee, Young; Allhusen, Virginia D.; Kim, Myoung Soon; McDowell, David J.

2006-01-01

192

The View from the Little Chair in the Corner: Improving Teacher Practice and Early Childhood Learning (Wisdom from an Experienced Classroom Observer)  

ERIC Educational Resources Information Center

This is a down-to-earth, heart-to-heart book about what it takes to be an exceptional early childhood teacher. The author uses her experience as a classroom observer and a developmental psychologist to create a rationale for best practice--the reasoning behind the best (worst and average) classroom practice. Cindy Rzasa Bess examines a variety of…

Bess, Cindy Rzasa

2009-01-01

193

Charted observations and the use of a paediatric early warning tool did not predict the majority of cardio-respiratory arrest calls in a paediatric hospital  

Microsoft Academic Search

AimTo asses whether the routine use of observation charts incorporating a Paediatric Early Warning Tool (PEWT) are effective for screening inpatients, predicting those at risk of acute deterioration, in a paediatric hospital.MethodA retrospective case note audit of all cardiac arrests calls for inpatients between May and December 2009 inclusive. Case notes, observation charts and computerised patient information records were studied

D Wright; G Sefton; M Horan

2011-01-01

194

Clinical assessment of peripheral perfusion to predict postoperative complications after major abdominal surgery early: a prospective observational study in adults  

PubMed Central

Introduction Altered peripheral perfusion is strongly associated with poor outcome in critically ill patients. We wanted to determine whether repeated assessments of peripheral perfusion during the days following surgery could help to early identify patients that are more likely to develop postoperative complications. Methods Haemodynamic measurements and peripheral perfusion parameters were collected one day prior to surgery, directly after surgery (D0) and on the first (D1), second (D2) and third (D3) postoperative days. Peripheral perfusion assessment consisted of capillary refill time (CRT), peripheral perfusion index (PPI) and forearm-to-fingertip skin temperature gradient (Tskin-diff). Generalized linear mixed models were used to predict severe complications within ten days after surgery based on Clavien-Dindo classification. Results We prospectively followed 137 consecutive patients, from among whom 111 were included in the analysis. Severe complications were observed in 19 patients (17.0%). Postoperatively, peripheral perfusion parameters were significantly altered in patients who subsequently developed severe complications compared to those who did not, and these parameters persisted over time. CRT was altered at D0, and PPI and Tskin-diff were altered on D1 and D2, respectively. Among the different peripheral perfusion parameters, the diagnostic accuracy in predicting severe postoperative complications was highest for CRT on D2 (area under the receiver operating characteristic curve = 0.91 (95% confidence interval (CI) = 0.83 to 0.92)) with a sensitivity of 0.79 (95% CI = 0.54 to 0.94) and a specificity of 0.93 (95% CI = 0.86 to 0.97). Generalized mixed-model analysis demonstrated that abnormal peripheral perfusion on D2 and D3 was an independent predictor of severe postoperative complications (D2 odds ratio (OR) = 8.4, 95% CI = 2.7 to 25.9; D2 OR = 6.4, 95% CI = 2.1 to 19.6). Conclusions In a group of patients assessed following major abdominal surgery, peripheral perfusion alterations were associated with the development of severe complications independently of systemic haemodynamics. Further research is needed to confirm these findings and to explore in more detail the effects of peripheral perfusion–targeted resuscitation following major abdominal surgery. PMID:24894892

2014-01-01

195

Mode decomposition evolution equations  

PubMed Central

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

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

2011-01-01

196

Mode decomposition evolution equations.  

PubMed

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

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

2012-03-01

197

Hydraulic redistribution may stimulate decomposition  

Microsoft Academic Search

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

Zachary T. Aanderud; James H. Richards

2009-01-01

198

Hydrogen iodide decomposition  

DOEpatents

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.

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

1983-01-01

199

Hydrogen iodide decomposition  

SciTech Connect

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/sup 0/ K. and about 525/sup 0/ 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.

O'Keefe, D.R.; Norman, J.H.

1983-10-18

200

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

Microsoft Academic Search

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

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

1997-01-01

201

The ATLAS3D project - XXII. Low-efficiency star formation in early-type galaxies: hydrodynamic models and observations  

E-print Network

We study the global efficiency of star formation in high resolution hydrodynamical simulations of gas discs embedded in isolated early-type and spiral galaxies. Despite using a universal local law to form stars in the simulations, we find that the early-type galaxies are offset from the spirals on the large-scale Kennicutt relation, and form stars 2 to 5 times less efficiently. This offset is in agreement with previous results on morphological quenching: gas discs are more stable against star formation when embedded in early-type galaxies due to the lower disc self-gravity and increased shear. As a result, these gas discs do not fragment into dense clumps and do not reach as high densities as in the spiral galaxies. Even if some molecular gas is present, the fraction of very dense gas (above 10^4 cm-3) is significantly reduced, which explains the overall lower star formation efficiency. We also analyse a sample of local early-type and spiral galaxies, measuring their CO and HI surface densities and their star...

Martig, Marie; Bournaud, Frederic; Emsellem, Eric; Gabor, Jared M; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bureau, Martin; Cappellari, Michele; Davies, Roger L; Davis, Timothy A; Dekel, Avishai; de Zeeuw, P T; Duc, Pierre-Alain; Falcon-Barroso, Jesus; Khochfar, Sadegh; Krajnovic, Davor; Kuntschner, Harald; Morganti, Raffaella; McDermid, Richard M; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Serra, Paolo; Griffin, Kristen Shapiro; Teyssier, Romain; Weijmans, Anne-Marie; Young, Lisa M

2012-01-01

202

Estimating the Effectiveness of Early Control Measures through School Absenteeism Surveillance in Observed Outbreaks at Rural Schools in Hubei, China  

PubMed Central

Background School absenteeism is a common data source in syndromic surveillance, which allows for the detection of outbreaks at an early stage. Previous studies focused on its correlation with other data sources. In this study, we evaluated the effectiveness of control measures based on early warning signals from school absenteeism surveillance in rural Chinese schools. Methods A school absenteeism surveillance system was established in all 17 primary schools in 3 adjacent towns in the Chinese region of Hubei. Three outbreaks (varicella, mumps, and influenza-like illness) were detected and controlled successfully from April 1, 2012, to January 15, 2014. An impulse susceptible-exposed-infectious-recovered model was used to fit the epidemics of these three outbreaks. Moreover, it simulated the potential epidemics under interventions resulting from traditional surveillance signals. The effectiveness of the absenteeism-based control measures was evaluated by comparing the simulated datasets. Results The school absenteeism system generated 52 signals. Three outbreaks were verified through epidemiological investigation. Compared to traditional surveillance, the school absenteeism system generated simultaneous signals for the varicella outbreak, but 3 days in advance for the mumps outbreak and 2–4 days in advance for the influenza-like illness outbreak. The estimated excess protection rates of control measures based on early signals were 0.0%, 19.0–44.1%, and 29.0–37.0% for the three outbreaks, respectively. Conclusions Although not all outbreak control measures can benefit from early signals through school absenteeism surveillance, the effectiveness of early signal-based interventions is obvious. School absenteeism surveillance plays an important role in reducing outbreak spread. PMID:25250786

Fan, Yunzhou; Yang, Mei; Jiang, Hongbo; Wang, Ying; Yang, Wenwen; Zhang, Zhixia; Yan, Weirong; Diwan, Vinod K.; Xu, Biao; Dong, Hengjin; Palm, Lars; Liu, Li; Nie, Shaofa

2014-01-01

203

Nitrogen Applications and Residue Decomposition 1/ Larry G. Bundy 2/  

E-print Network

higher early season soil temperatures in no-till corn systems. In a 3-yr field experiment, ammonium decomposition did not improve no-till corn yields and do not appear to be justified. Fall N did not consistently surface applied in no-till systems. ___________________________ 1 Prepared for the 2001 Area Fertilizer

Balser, Teri C.

204

Singular value decomposition and spectral analysis  

Microsoft Academic Search

Linear-Prediction-based (LP) methods for fitting multiple-sinusoid signal models to observed data, such as the forward-backward (FBLP) method of Nuttall (5) and Ulrych and Clayton (6), are very ill-conditioned. The locations of estimated spectral peaks can be greatly affected by a small amount of additive noise. LP estimation of frequencies can be greatly improved by singular value decomposition of the LP

Ramdas Kumaresan; Donald W. Tufts

1981-01-01

205

Merging images through pattern decomposition  

Microsoft Academic Search

Describes an approach to image merging based on pattern decomposition. Each source image is first transformed into a set of primitive pattern elements. Pattern sets for the various source images are then combined to form a single set for the composite image. Finally the composite is reconstructed from its set of primitives. The authors illustrate the pattern decomposition technique with

P. J. Burt; E. H. Adelson

1985-01-01

206

Thermal plasma decomposition of chlorofluorocarbons  

Microsoft Academic Search

Dichlorodifluoromethane was decomposed by a thermal argon plasma generated by a DC are discharge. The experiments and the kinetic calculations showed that the complete decomposition of the chlorofluorocarbon proceeded with the simultaneous additions of hydrogen and oxygen. Both the expertimental and calculated results confirmed that it is favorable, for the decomposition, not to quench the products but to add an

Hidetoshi Sekiguchi; Takuya Honda; Atsushi Kanzawa

1993-01-01

207

Conditional Dependencies for Horizontal Decompositions  

Microsoft Academic Search

A new decomposition theory for functional dependencies in the Relational Database Model is given. It uses a method to break up a relation into two subrelations whose union is the given relation. This horizontal decomposition is based on a new constraint: the conditional-functional dependency. It indicates how to decompose a relation into two restrictions of this relation. The only difference

Paul De Bra; Jan Paredaens

1983-01-01

208

Thermal Decomposition of Nitric Oxide  

Microsoft Academic Search

The decomposition of pure nitric oxide and of mixtures with nitrogen or helium was studied at T = 1170 to 1530°K in quartz vessels. Above about T = 1400°K, the reaction is homogeneous and cleanly second order in NO throughout the course of decomposition. A change in the surface to volume ratio leaves the rate unchanged as does the addition

Frederick Kaufman; John R. Kelso

1955-01-01

209

Automatic Text Decomposition and Structuring  

Microsoft Academic Search

Sophisticated text similarity measurements are used to determine relationships between natural-language texts and text excerpts. The resulting linked hypertext maps can be decomposed into text segments and text themes, and these decompositions are usable to identify different text types and text structures, leading to improved text access and utilization. Examples of text decomposition are given for expository and non-expository texts.

Gerard Salton; James Allan; Amit Singhal

1996-01-01

210

Direct Sum Decomposition of Groups  

ERIC Educational Resources Information Center

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…

Thaheem, A. B.

2005-01-01

211

Reactive Goal Decomposition Hierarchies for On-Board Autonomy  

NASA Astrophysics Data System (ADS)

As our experience grows, space missions and systems are expected to address ever more complex and demanding requirements with fewer resources (e.g., mass, power, budget). One approach to accommodating these higher expectations is to increase the level of autonomy to improve the capabilities and robustness of on- board systems and to simplify operations. The goal decomposition hierarchies described here provide a simple but powerful form of goal-directed behavior that is relatively easy to implement for space systems. A goal corresponds to a state or condition that an operator of the space system would like to bring about. In the system described here goals are decomposed into simpler subgoals until the subgoals are simple enough to execute directly. For each goal there is an activation condition and a set of decompositions. The decompositions correspond to different ways of achieving the higher level goal. Each decomposition contains a gating condition and a set of subgoals to be "executed" sequentially or in parallel. The gating conditions are evaluated in order and for the first one that is true, the corresponding decomposition is executed in order to achieve the higher level goal. The activation condition specifies global conditions (i.e., for all decompositions of the goal) that need to hold in order for the goal to be achieved. In real-time, parameters and state information are passed between goals and subgoals in the decomposition; a termination indication (success, failure, degree) is passed up when a decomposition finishes executing. The lowest level decompositions include servo control loops and finite state machines for generating control signals and sequencing i/o. Semaphores and shared memory are used to synchronize and coordinate decompositions that execute in parallel. The goal decomposition hierarchy is reactive in that the generated behavior is sensitive to the real-time state of the system and the environment. That is, the system is able to react to state and environment and in general can terminate the execution of a decomposition and attempt a new decomposition at any level in the hierarchy. This goal decomposition system is suitable for workstation, microprocessor and fpga implementation and thus is able to support the full range of prototyping activities, from mission design in the laboratory to development of the fpga firmware for the flight system. This approach is based on previous artificial intelligence work including (1) Brooks' subsumption architecture for robot control, (2) Firby's Reactive Action Package System (RAPS) for mediating between high level automated planning and low level execution and (3) hierarchical task networks for automated planning. Reactive goal decomposition hierarchies can be used for a wide variety of on-board autonomy applications including automating low level operation sequences (such as scheduling prerequisite operations, e.g., heaters, warm-up periods, monitoring power constraints), coordinating multiple spacecraft as in formation flying and constellations, robot manipulator operations, rendez-vous, docking, servicing, assembly, on-orbit maintenance, planetary rover operations, solar system and interstellar probes, intelligent science data gathering and disaster early warning. Goal decomposition hierarchies can support high level fault tolerance. Given models of on-board resources and goals to accomplish, the decomposition hierarchy could allocate resources to goals taking into account existing faults and in real-time reallocating resources as new faults arise. Resources to be modeled include memory (e.g., ROM, FPGA configuration memory, processor memory, payload instrument memory), processors, on-board and interspacecraft network nodes and links, sensors, actuators (e.g., attitude determination and control, guidance and navigation) and payload instruments. A goal decomposition hierarchy could be defined to map mission goals and tasks to available on-board resources. As faults occur and are detected the resource allocation is modified to avoid using the f

Hartmann, L.

2002-01-01

212

Art of spin decomposition  

E-print Network

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.

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

2011-05-31

213

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

NASA Astrophysics Data System (ADS)

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 record to be placed in the context of the period 1823-1996. The period since the early 1970s is the most prolonged positive phase of the oscillation and the late 1980s and early 1990s is the period with the highest values (strongest westerlies). The winter of 1995-1996 marked a dramatic switch in the index, with the change from 1994-1995 being the greatest change recorded from one year to the next since the series began in 1823. (The extended Gibraltar and Reykjavik monthly pressures and the NAO series can be found on the Climatic Research Unit home page, http://www.cru.uea.ac.uk/.).

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

1997-11-01

214

Polymerization-induced spinodal decomposition of ethylene glycol/phenolic resin solutions under electric fields  

NASA Astrophysics Data System (ADS)

Temporal evolution of polymerization-induced spinodal decomposition (PISD) under electric fields was investigated numerically in ethylene glycol/phenolic resin solutions with different initial composition. A model composed of the nonlinear Cahn-Hilliard-Cook equation for spinodal decomposition and a rate equation for curing reaction was utilized to describe the PISD phenomenon. As initial composition varied, deformed droplet-like and aligned bi-continuous structures were observed in the presence of an electric field. Moreover, the anisotropic parameter (D), determined from the 2D-FFT power spectrum, was employed to quantitatively characterize the degree of morphology anisotropy. The value of D increased quickly in the early stage and then decreased in the intermediate stage of spinodal decomposition, which was attributed to the resistance of coarsening process to morphology deformation and the decline of electric stress caused by polymerization reaction. The results can also provide a guidance on how to control the morphology of monolithic porous polymer and carbon materials with anisotropic structures.

Zhang, Gang; Qiao, Guanjun

2013-10-01

215

A Large Web-Based Observer Reliability Study of Early Ischaemic Signs on Computed Tomography. The Acute Cerebral CT Evaluation of Stroke Study (ACCESS)  

PubMed Central

Background Early signs of ischaemic stroke on computerised tomography (CT) scanning are subtle but CT is the most widely available diagnostic test for stroke. Scoring methods that code for the extent of brain ischaemia may improve stroke diagnosis and quantification of the impact of ischaemia. Methodology and Principal Findings We showed CT scans from patients with acute ischaemic stroke (n?=?32, with different patient characteristics and ischaemia signs) to doctors in stroke-related specialties world-wide over the web. CT scans were shown twice, randomly and blindly. Observers entered their scan readings, including early ischaemic signs by three scoring methods, into the web database. We compared observers' scorings to a reference standard neuroradiologist using area under receiver operator characteristic curve (AUC) analysis, Cronbach's alpha and logistic regression to determine the effect of scales, patient, scan and observer variables on detection of early ischaemic changes. Amongst 258 readers representing 33 nationalities and six specialties, the AUCs comparing readers with the reference standard detection of ischaemic signs were similar for all scales and both occasions. Being a neuroradiologist, slower scan reading, more pronounced ischaemic signs and later time to CT all improved detection of early ischaemic signs and agreement on the rating scales. Scan quality, stroke severity and number of years of training did not affect agreement. Conclusions Large-scale observer reliability studies are possible using web-based tools and inform routine practice. Slower scan reading and use of CT infarct rating scales improve detection of acute ischaemic signs and should be encouraged to improve stroke diagnosis. PMID:21209901

Wardlaw, Joanna M.; von Kummer, Rudiger; Farrall, Andrew J.; Chappell, Francesca M.; Hill, Michael; Perry, David

2010-01-01

216

Hydroxyl radical formation during peroxynitrous acid decomposition  

SciTech Connect

Yields of O{sub 2} formed during decomposition of peroxynitrous acid (ONOOH) under widely varying medium conditions are compared to predictions based upon the assumption that the reaction involves formation of discrete {sm{underscore}bullet}OH and {sm{underscore}bullet}NO{sub 2} radicals as oxidizing intermediates. The kinetic model used includes all reactions of {sm{underscore}bullet}OH, {sm{underscore}bullet}O{sub 2}{sup {minus}}, and reactive nitrogen species known to be important under the prevailing conditions; because the rate constants for all of these reactions have been independently measured, the calculations contain no adjustable fitting parameters. The model quantitatively accounts for (1) the complex pH dependence of the O{sub 2} yields and (2) the unusual effects of NO{sub 2} {sup {minus}}, which inhibits O{sub 2} formation in neutral, but not alkaline, solutions and also reverses inhibition by organic {sm{underscore}bullet}OH scavengers in alkaline media. Other observations, including quenching of O{sub 2} yields by ferrocyanide and bicarbonate, the pressure dependence of the decomposition rate, and the reported dynamic behavior for O{sub 2} generation in the presence of H{sub 2}O{sub 2}, also appear to be in accord with the suggested mechanism. Overall, the close correspondence between observed and calculated O{sub 2} yields provides strong support for decomposition via homolysis of the ONOOH peroxo bond.

Coddington, J.W.; Hurst, J.K.; Lymar, S.V.

1999-03-24

217

Azimuthal decomposition with digital holograms.  

PubMed

We demonstrate a simple approach, using digital holograms, to perform a complete azimuthal decomposition of an optical field. Importantly, we use a set of basis functions that are not scale dependent so that unlike other methods, no knowledge of the initial field is required for the decomposition. We illustrate the power of the method by decomposing two examples: superpositions of Bessel beams and Hermite-Gaussian beams (off-axis vortex). From the measured decomposition we show reconstruction of the amplitude, phase and orbital angular momentum density of the field with a high degree of accuracy. PMID:22565722

Litvin, Igor A; Dudley, Angela; Roux, Filippus S; Forbes, Andrew

2012-05-01

218

Perfluoropolyalkylether decomposition on catalytic aluminas  

NASA Technical Reports Server (NTRS)

The decomposition of Fomblin Z25, a commercial perfluoropolyalkylether liquid lubricant, was studied using the Penn State Micro-oxidation Test, and a thermal gravimetric/differential scanning calorimetry unit. The micro-oxidation test was conducted using 440C stainless steel and pure iron metal catalyst specimens, whereas the thermal gravimetric/differential scanning calorimetry tests were conducted using catalytic alumina pellets. Analysis of the thermal data, high pressure liquid chromatography data, and x-ray photoelectron spectroscopy data support evidence that there are two different decomposition mechanisms for Fomblin Z25, and that reductive sites on the catalytic surfaces are responsible for the decomposition of Fomblin Z25.

Morales, Wilfredo

1994-01-01

219

Descent theory for semiorthogonal decompositions  

SciTech Connect

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.

Elagin, Alexei D

2012-05-31

220

Lateral biases for holding infants: early opinions, observations, and explanations, with some possible lessons for theory and research today.  

PubMed

In 1962, the psychologist Lee Salk reported finding that 80% of mothers held their infants on the left side of their body, so that the infant's head was to their left. Salk's finding has been amply confirmed, with new studies of mothers as well as other adults reporting figures for left-side holding ranging from 60 to 85% (e.g., de Chateau, 1983; Harris & Fitzgerald, 1985; Harris, Almerigi, & Kirsch, 2000). New studies also suggest that the bias is only for holding infants (or infant dolls), not for books, packages, or other objects (e.g., Almerigi, Carbary, & Harris, 2001; Rheingold & Keene, 1965). The possibility that it is unique to infants (or their likenesses) is what gives it special interest for investigators who study laterality of function. The discovery of the bias is often credited to Salk, but it would be more accurate to say that he rediscovered it because it was first noted at least two hundred years earlier, then, evidently, forgotten, only to be rediscovered and again forgotten several times through the early decades of the twentieth century. Over this period, however, not all agreed that the preferred side was the left: a nearly equal number said it was the right. Each group also proposed explanations for why one or the other side was preferred. They also foresaw different consequences for the infant being held. In the 1980s, I briefly described some of the early reports in essays on the history of theories and research on laterality of function (Harris, 1980, 1983). A manuscript now in preparation provides a more comprehensive description and evaluation of these reports and suggests certain lessons they may hold for current theory and research. The poster proposed for TENNET XII will summarize the main points of this new review and analysis. The poster will be organized into 6 sections, with bulleted text accompanied by drawings, photographs, and other illustrations. The plan is to make the story as visual as possible. PMID:12030474

Harris, Lauren Julius

2002-01-01

221

Shock wave induced decomposition of RDX: time-resolved spectroscopy.  

PubMed

Time-resolved optical spectroscopy was used to examine chemical decomposition of RDX crystals shocked along the [111] orientation to peak stresses between 7 and 20 GPa. Shock-induced emission, produced by decomposition intermediates, was observed over a broad spectral range from 350 to 850 nm. A threshold in the emission response of RDX was found at about 10 GPa peak stress. Below this threshold, the emission spectrum remained unchanged during shock compression. Above 10 GPa, the emission spectrum changed with a long wavelength component dominating the spectrum. The long wavelength emission is attributed to the formation of NO2 radicals. Above the 10 GPa threshold, the spectrally integrated intensity increased significantly, suggesting the acceleration of chemical decomposition. This acceleration is attributed to bimolecular reactions between unreacted RDX and free radicals. These results provide a significant experimental foundation for further development of a decomposition mechanism for shocked RDX (following paper in this issue). PMID:18642891

Patterson, James E; Dreger, Zbigniew A; Miao, Maosheng; Gupta, Yogendra M

2008-08-14

222

CHINESE JOURNAL OF PHYSICS VOL. lo, NO. 2 OCTOBER, 1972 Fractional Parentage Decomposition of the Baryonic Quark States*  

E-print Network

CHINESE JOURNAL OF PHYSICS VOL. lo, NO. 2 OCTOBER, 1972 Fractional Parentage Decomposition" in the decompositions are listed. Some applications of the decomposition to the evaluation of the matrix elements of the matrix elements of one-body and two-body quark operators are illustrated. 1. INTRODUCTION 7r HE observed

Chu, Shih-I

223

Ceramic decomposition under irradiation, 1987  

SciTech Connect

Our quantitative determinations of the decomposition of thin film and bulk ceramic materials during electron microscopy has shown that the radiation damage effect is a complex one depending dielectric and thermochemical properties. In low melting temperature glasses, for example, much of the activity is due to field enhanced diffusion of low atomic weight species. This is particularly true of bulk specimens and for the case of binary soda-borosilicate glass the sodium depletion in the SEM can be quantitatively described in terms of this effect. Studies with thin specimens of refractory carbides show that in these materials the carbon depletion is due to direct displacement processes and that here the electric fields give rise to recombination effects. The studies of ceramic thin films suitable for reference standards is continuing as a joint effort with the Rockwell Science Center. Work is in progress to describe the in plane crystallization that is observed in terms of the latent heat involved and the configurational entropy of the propagating interface.

Howitt, D.G.

1987-01-01

224

Stratospheric aerosol change in the early stage of volcanic disturbance by the Pinatubo eruption observed over Tsukuba, Japan  

SciTech Connect

An increase in the amount of stratospheric aerosol due to the Pinatubo eruption (June 12-15, 1991, 15.14[degree]N, 120.35[degree]E) was observed from the end of June by a lidar in NIES, Tsukuba (36[degree]N, 140[degree]E). The first arrival of volcanic aerosol layers was observed just above the tropopause on June 28, 1991, only two weeks after the eruption. Aerosol layers higher than 20 km appeared sporadically in July and August, reflecting the inhomogeneity of aerosol distribution. After the change in the wind system from summer easterlies to winter westerlies, the main body of the volcanic aerosol layer made its appearance over Tsukuba. The integrated backscattering coefficient (IBC) increased in winter as a result of transportation of aerosols from the tropical region. The IBC, which can be converted to optical thickness, exceeded the level of the value observed after the El Chichon eruption. 15 refs., 4 figs.

Hayashida, Sachiko; Sasano, Yasuhiro

1993-04-09

225

Updating the singular value decomposition  

Microsoft Academic Search

Summary LetA be anm×n matrix with known singular value decomposition. The computation of the singular value decomposition of a matrixà is considered, whereà is obtained by appending a row or a column toA whenm?n or by deleting a row or a column fromA whenm>n. An algorithm is also presented for solving the updated least squares problemà y-b˜, obtained from the

James R. Bunch; Christopher P. Nielsen

1978-01-01

226

Optimization by nonhierarchical asynchronous decomposition  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

227

Photopromoted and thermal decomposition of nitric oxide by metal oxides. Final report, 12 June 1989-30 June 1991  

SciTech Connect

This technical report summarizes research on decomposition of NOx by photopromoted and thermal solid-catalyzed decomposition of NO. Typical catalysts incorporated one or more metal oxides. Photopromotion of catalytic activity was observed with several catalysts. Nearly complete thermal decomposition of NO was achieved by several catalysts in the absence of O[sub 2]. However, no combination of catalyst and conditions achieved satisfactory rates of decomposition of NO in the presence of target concentrations (>10 percent) of O[sub 2].

Berman, E.; Dong, J.; Lichtin, N.N.

1992-04-01

228

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

Microsoft Academic Search

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

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

2006-01-01

229

Functional Dependency Implications, Inducing Horizontal Decompositions  

Microsoft Academic Search

A new decomposition theory for the Relational Database Model is given. It uses a horizontal decomposition of a relation into two disjoint subrelations, of which the union is the given relation. This horizontal decomposition is based on a new constraint, the functional dependency implication (fdi), which is a partial implication between functional dependencies (fd's). This horizontal decomposition is especially useful

Paul De Bra

1987-01-01

230

Chandra and VLA Observations of Supermassive Black Hole Outbursts in M87 and Implications for Feedback in Early-Type Galaxies  

NASA Astrophysics Data System (ADS)

We discuss the effects of supermassive black hole (SMBH) outbursts on the hot atmospheres surrounding massive galaxies as observed with X-ray and radio observations. We initially focus on a detailed study of outbursts from the supermassive black hole in M87 using Chandra and VLA observations. We model the outburst that created the classical Mach 1.2 shock seen in Chandra images and derive the characteristic energy (5x1057 ergs), duration (2 Myrs), and age (12 Myrs) of the outburst from numerical models. We review the outburst history of the SMBH in M87 over the past ~100 Myr. We discuss the implications of the outbursts for feedback in typical early-type galaxy atmospheres.

Forman, William R.; Churazov, E.; Jones, C.

2013-04-01

231

Loss of diversity in wood-inhabiting fungal communities affects decomposition activity in Norway spruce wood.  

PubMed

Hundreds of wood-inhabiting fungal species are now threatened, principally due to a lack of dead wood in intensively managed forests, but the consequences of reduced fungal diversity on ecosystem functioning are not known. Several experiments have shown that primary productivity is negatively affected by a loss of species, but the effects of microbial diversity on decomposition are less studied. We studied the relationship between fungal diversity and the in vitro decomposition rate of slightly, moderately and heavily decayed Picea abies wood with indigenous fungal communities that were diluted to examine the influence of diversity. Respiration rate, wood-degrading hydrolytic enzymes and fungal community structure were assessed during a 16-week incubation. The number of observed OTUs in DGGE was used as a measure of fungal diversity. Respiration rate increased between early- and late-decay stages. Reduced fungal diversity was associated with lower respiration rates during intermediate stages of decay, but no effects were detected at later stages. The activity of hydrolytic enzymes varied among decay stages and fungal dilutions. Our results suggest that functioning of highly diverse communities of the late-decay stage were more resistant to the loss of diversity than less diverse communities of early decomposers. This indicates the accumulation of functional redundancy during the succession of the fungal community in decomposing substrates. PMID:24904544

Valentín, Lara; Rajala, Tiina; Peltoniemi, Mikko; Heinonsalo, Jussi; Pennanen, Taina; Mäkipää, Raisa

2014-01-01

232

Loss of diversity in wood-inhabiting fungal communities affects decomposition activity in Norway spruce wood  

PubMed Central

Hundreds of wood-inhabiting fungal species are now threatened, principally due to a lack of dead wood in intensively managed forests, but the consequences of reduced fungal diversity on ecosystem functioning are not known. Several experiments have shown that primary productivity is negatively affected by a loss of species, but the effects of microbial diversity on decomposition are less studied. We studied the relationship between fungal diversity and the in vitro decomposition rate of slightly, moderately and heavily decayed Picea abies wood with indigenous fungal communities that were diluted to examine the influence of diversity. Respiration rate, wood-degrading hydrolytic enzymes and fungal community structure were assessed during a 16-week incubation. The number of observed OTUs in DGGE was used as a measure of fungal diversity. Respiration rate increased between early- and late-decay stages. Reduced fungal diversity was associated with lower respiration rates during intermediate stages of decay, but no effects were detected at later stages. The activity of hydrolytic enzymes varied among decay stages and fungal dilutions. Our results suggest that functioning of highly diverse communities of the late-decay stage were more resistant to the loss of diversity than less diverse communities of early decomposers. This indicates the accumulation of functional redundancy during the succession of the fungal community in decomposing substrates. PMID:24904544

Valentin, Lara; Rajala, Tiina; Peltoniemi, Mikko; Heinonsalo, Jussi; Pennanen, Taina; Makipaa, Raisa

2014-01-01

233

Decomposition rates and termite assemblage composition in semiarid Africa  

USGS Publications Warehouse

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.

Schuurman, G.

2005-01-01

234

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

Microsoft Academic Search

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

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

235

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

SciTech Connect

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.

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

236

Early Radio and X-Ray Observations of the Youngest Nearby Type Ia Supernova PTF 11kly (SN 2011fe)  

NASA Technical Reports Server (NTRS)

On 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(raised dot) less than or equal to 10(exp -8) (w /100 kilometers per second ) solar mass yr(exp -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 (decade or longer) in order to more meaningfully probe the circumstellar matter of Ia supernovae.

Horesh, Assaf; Kulkarni, S. R.; Fox, Derek B.; Carpenter, John; Kasliwal, Mansi M.; Ofek, Eran O.; Quimby, Robert; Gal-Yam, Avishay; Cenko, S. Bradley; deBruyn, A. G.; Kamble, Atish; Wijers, Ralph A. M. J.; vanderHorst, Alexander J.; Kouveliotou, Chryssa; Podsiadlowski, Philipp; Sullivan, Mark; Maguire, Kate; Howell, D. Andrew; Nugent, Peter E.; Gehrels, Neil; Law, Nicolas M.; Poznanski, Dovi; Shara, Michael

2012-01-01

237

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

SciTech Connect

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.

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

238

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)

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.

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

2014-10-01

239

EARLY- AND LATE-TIME OBSERVATIONS OF SN 2008ha: ADDITIONAL CONSTRAINTS FOR THE PROGENITOR AND EXPLOSION  

SciTech Connect

We present a new maximum-light optical spectrum of the extremely low luminosity and exceptionally low-energy Type Ia supernova (SN Ia) 2008ha, obtained one week before the earliest published spectrum. Previous observations of SN 2008ha were unable to distinguish between a massive star and white dwarf (WD) origin for the SN. The new maximum-light spectrum, obtained one week before the earliest previously published spectrum, unambiguously shows features corresponding to intermediate mass elements, including silicon, sulfur, and carbon. Although strong silicon features are seen in some core-collapse SNe, sulfur features, which are a signature of carbon/oxygen burning, have always been observed to be weak in such events. It is therefore likely that SN 2008ha was the result of a thermonuclear explosion of a carbon-oxygen WD. Carbon features at maximum light show that unburned material is present to significant depths in the SN ejecta, strengthening the case that SN 2008ha was a failed deflagration. We also present late-time imaging and spectroscopy that are consistent with this scenario.

Foley, Ryan J.; Challis, Peter J.; Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Brown, Peter J. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Rest, Armin [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States); Wood-Vasey, W. Michael [Department of Physics and Astronomy, 100 Allen Hall, 3941 O'Hara Street, University of Pittsburgh, Pittsburgh, PA 15260 (United States)], E-mail: rfoley@cfa.harvard.edu

2010-01-01

240

Health disparities between racial groups in South Africa: A decomposition analysis  

Microsoft Academic Search

This article explores the sources of self-rated health status inequalities among South Africans. We propose a decomposition of observed health disparities between racial groups using a procedure based on an extended version of Oaxaca–Blinder decomposition methods which addresses explicitly the specificities associated with the analysis of subjective measures. This method allows for a decompositions of differences in self-rated health status

Cécile Charasse-Pouélé; Martin Fournier

2006-01-01

241

Study on Decomposition of Goethite/siderite in Thermal Modification Through XRD, SEM and Tga Measurements  

NASA Astrophysics Data System (ADS)

The decomposition of goethite and goethite/siderite concentrates into hematite with thermal modification was studied through the measurements of X-ray diffraction (XRD), scanning electronic microscope (SEM) and thermal gravimetric analysis (TGA). The experimental results showed that goethite decomposed into hematite directly at around 300°C without any intermediate phase and the decomposition of siderite completed at 500°C. Nanoscale granular structures were observed in the thermally treated products. It deserves highlighting that the decomposition processes proceeded from surfaces into bulks.

Song, Shaoxian; Jia, Feifei; Peng, Changsheng

2014-01-01

242

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

NASA Technical Reports Server (NTRS)

We present results on the X-ray and optical/UV emission from the Type IIP supernova (SN) 2006bp and the interaction of the SW 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 sigmalevel of significance in the merged XRT data from days 1 to 12 after the explosion. If the (0.2-10 keV band) X-ray luminosity of L(sub 0.2-10) = (1.8 plus or minus 0.4) x l0(exp 39 ergs s(exp -1) 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 M is approximately 2x10(exp -6) solar mass yr(exp -1) (v(sub w)/10 km s(exp -l) is inferred. The mass-loss rate is one of the lowest ever recorded for a core-collapse SN and consistent with the non-detection in the radio with the VLA on days 2, 9, and 11 after the explosion. The Swift data further show a fading of the X-ray emission starting around day 12 after the explosion. In combination with a follow-up XMM-Newton observation obtained on day 21 after the explosion, an X-ray rate of decline Lx, varies as t(exp -n) with index n = 1.2 plus or minus 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 (approximately 10-100), inconsistent with the ejecta velocity inferred from optical line widths, we conclude that Inverse Compton scattering is an unlikely explanation for the observed X-ray emission. The fast evolution of the optical/ultraviolet (1900-5500A) 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.

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

2007-01-01

243

Are Decomposition Slices Clones?  

Microsoft Academic Search

When computing program slices on all variables in a sys- tem, we observed that many of these slices are the same. This leads to the question: Are we looking at software clones? We discuss the genesis of this phenomena and present some of the data observations that led to the ques- tion. The answer to our query is not immediately

Keith Gallagher; Lucas Layman

2003-01-01

244

Nearby Supernova Factory Observations of SN 2006D: On Sporadic Carbon Signatures in Early Type Ia Supernova Spectra  

E-print Network

We present four spectra of the Type Ia supernova (SN Ia) 2006D extending from -7 to +13 days with respect to B-band maximum. The spectra include the strongest signature of unburned material at photospheric velocities observed in a SN Ia to date. The earliest spectrum exhibits C II absorption features below 14,000 km/s, including a distinctive C II \\lambda 6580 absorption feature. The carbon signatures dissipate as the SN approaches peak brightness. In addition to discussing implications of photospheric-velocity carbon for white dwarf explosion models, we outline some factors that may influence the frequency of its detection before and around peak brightness. Two effects are explored in this regard, including depopulation of the C II optical levels by non-LTE effects, and line-of-sight effects resulting from a clumpy distribution of unburned material with low volume-filling factor.

The Nearby Supernova Factory; :; R. C. Thomas; G. Aldering; P. Antilogus; C. Aragon; S. Bailey; C. Baltay; E. Baron; A. Bauer; C. Buton; S. Bongard; Y. Copin; E. Gangler; S. Gilles; R. Kessler; S. Loken; P. Nugent; R. Pain; J. Parrent; E. Pecontal; R. Pereira; S. Perlmutter; D. Rabinowitz; G. Rigaudier; K. Runge; R. Scalzo; G. Smadja; L. Wang; B. A. Weaver

2006-11-10

245

Early X-ray and optical observations of the soft gamma-ray repeater SGR0418+5729  

NASA Astrophysics Data System (ADS)

Emission of two short hard X-ray bursts on 2009 June 5 disclosed the existence of a new soft gamma-ray repeater, now catalogued as SGR0418+5729. After a few days, X-ray pulsations at a period of 9.1s were discovered in its persistent emission. SGR0418+5729 was monitored almost since its discovery with the Rossi X-ray Timing Explorer (2-10keV energy range) and observed many times with Swift (0.2-10keV). The source persistent X-ray emission faded by a factor of ~10 in about 160 d, with a steepening in the decay about 19 d after the activation. The X-ray spectrum is well described by a simple absorbed blackbody, with a temperature decreasing in time. A phase-coherent timing solution over the ~160 d time-span yielded no evidence for any significant evolution of the spin period, implying a 3? upper limit of 1.1 × 10-13s s-1 on the period derivative and of ~3 × 1013G on the surface dipole magnetic field. Phase-resolved spectroscopy provided evidence for a significant variation of the spectrum as a function of the stellar rotation, pointing to the presence of two emitting caps, one of which became hotter during the outburst. Finally, a deep observation of the field of SGR0418+5729 with the new Gran Telescopio Canarias 10.4-m telescope allowed us to set an upper limit on the source optical flux of i' > 25.1mag, corresponding to an X-ray-to-optical flux ratio exceeding 104, consistent with the characteristics of other magnetars.

Esposito, P.; Israel, G. L.; Turolla, R.; Tiengo, A.; Götz, D.; de Luca, A.; Mignani, R. P.; Zane, S.; Rea, N.; Testa, V.; Caraveo, P. A.; Chaty, S.; Mattana, F.; Mereghetti, S.; Pellizzoni, A.; Romano, P.

2010-07-01

246

Satellite observations of terrestrial water storage provide early warning information about drought and fire season severity in the Amazon  

NASA Astrophysics Data System (ADS)

risk in the Amazon can be predicted several months before the onset of the dry season using sea surface temperatures in the tropical north Atlantic and tropical Pacific. The lead times between ocean state and the period of maximum burning (4-11 months) may enable the development of forecasts with benefits for forest conservation, yet the underlying physical and biological mechanisms responsible for these temporal offsets are not well known. Here, we examined the hypothesis that year-to-year variations in soil water recharge during the wet season modify atmospheric water vapor and fire behavior during the following dry season. We tested this hypothesis by analyzing terrestrial water storage observations from the Gravity Recovery and Climate Experiment (GRACE), active fires from the Moderate Resolution Imaging Spectroradiometer (MODIS), and several other satellite and atmospheric reanalysis datasets during 2002-2011. We found that terrestrial water storage deficits preceded severe fire seasons across the southern Amazon. The most significant relationships between monthly terrestrial water storage and the sum of active fires during the dry season occurred during April-August (p < 0.02), corresponding to 1-5 month lead times before the peak month of burning (September). Analysis of other datasets provided evidence for a cascade of processes during drought events, with lower cumulative precipitation (and higher cumulative evapotranspiration) in the wet season substantially reducing terrestrial water storage, and subsequently, surface and column atmospheric water vapor. Our results suggest that terrestrial water storage observations from GRACE have the potential to improve fire season forecasts for the southern Amazon.

Chen, Yang; Velicogna, Isabella; Famiglietti, James S.; Randerson, James T.

2013-06-01

247

Deep Chandra X-ray Observations of Low Mass X-ray Binary Candidates in the Early-Type Galaxy NGC 4697  

E-print Network

Chandra X-ray observations routinely resolve tens to hundreds of low-mass X-ray binaries (LMXBs) per galaxy in nearby massive early-type galaxies. These studies have raised important issues regarding the behavior of this population of remnants of the once massive stars in early-type galaxies, namely the connection between LMXBs and globular clusters (GCs) and the nature of the LMXB luminosity function (LF). In this paper, we combine five epochs of Chandra observations and one central field Hubble Space Telescope Advance Camera for Surveys observation of NGC 4697, one of the nearest, optically luminous elliptical (E6) galaxies, to probe the GC-LMXB connection and LMXB-LF down to a detection/completeness limit of (0.6/1.4) x 10^{37} ergs/s. We detect 158 sources, present their luminosities and hardness ratios, and associate 34 LMXBs with GCs. We confirm that GCs with higher encounter rates (\\Gamma_h) and redder colors (higher metallicity Z) are more likely to contain GCs, and find that the expected number of LMXBs per GC is proportional to \\Gamma_h^{0.79+0.18/-0.15} Z^{0.50+0.20/-0.18}, consistent with fainter X-ray sources in Galactic GCs and LMXBs in Virgo early-type galaxies. Approximately 11+/-2% / 8 +/-2% of GCs in NGC 4697 contain an LMXB at the detection/completeness limit. We propose that the larger proportion of metal-rich GCs in NGC 4697 compared to the Milky Way explains why these fractions are much higher than those of the Milky Way at similar luminosities. We confirm that a broken power-law is the best fit to the LMXB-LF, although we cannot rule out a cutoff power-law, and argue that this raises the possibility that there is no universal form for the LMXB-LF in early-type galaxies. We find marginal evidence for different LFs of LMXBs in GCs and the field and different spectra of GC-LMXBs and Field-LMXBs.

Gregory R. Sivakoff; Andrés Jordán; Adrienne M. Juett; Craig L. Sarazin; Jimmy A. Irwin

2008-06-03

248

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 Technical Reports Server (NTRS)

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.

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

2004-01-01

249

The Resolved Stellar Population in 50 Regions of M83 from HST/WFC3 Early Release Science Observations  

E-print Network

We present a multi-wavelength photometric study of ~15,000 resolved stars in the nearby spiral galaxy M83 (NGC5236, D=4.61Mpc) 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 towards 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...

Kim, Hwihyun; Chandar, Rupali; Saha, Abhijit; Kaleida, Catherine C; Mutchler, Max; Cohen, Seth H; Calzetti, Daniela; O'Connell, Robert W; Windhorst, Rogier A; Balick, Bruce; Bond, Howard E; Carollo, C Marcella; Disney, Michael J; Dopita, Michael A; Frogel, Jay A; Hall, Donald N B; Holtzman, Jon A; Kimble, Randy A; McCarthy, Patrick J; Paresce, Francesco; Silk, Joe I; Trauger, John T; Walker, Alistair R; Young, Erick T

2012-01-01

250

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

SciTech Connect

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.

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

251

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

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

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

252

Kinetics of the pyrolytic and hydrothermal decomposition of water hyacinth.  

PubMed

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

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

2011-07-01

253

Substructuring decomposition and controller synthesis  

NASA Technical Reports Server (NTRS)

A decentralized design procedure is proposed for the control design for flexible structures. The structure to be controlled is decomposed into several substructures by using a natural decomposition called substructuring decomposition. For each substructure, a subcontroller is designed by using the linear quadratic optimal control theory. Then, a controller synthesis scheme called Substructural Controller Synthesis (SCS) is used to assemble the subcontrollers into a system controller, which is to be used to control the whole structure. A plane truss example is used to illustrate the efficacy of the proposed method.

Su, Tzu-Jeng; Craig, Roy R., Jr.

1990-01-01

254

Effects observed in the Latin American sector ionospheric F region during the intense geomagnetic disturbances in the early part of November 2004  

NASA Astrophysics Data System (ADS)

The Sun was very active in the early part of November 2004. During the period of 8-10 November 2004, intense geomagnetic disturbances with two superstorms were observed. In this paper, we have investigated the generation and suppression of equatorial ionospheric irregularities and the daytime changes in the F region electron density in the Latin American sector during the period of intense geomagnetic disturbances. We present the ionospheric sounding observations carried out at Manaus and Sao Jose dos Campos, Brazil, during this geomagnetically disturbed period. Also, GPS observations obtained from several stations in Brazil, Argentina, and St. Croix, U.S. Virgin Islands, during the disturbed period are presented. During the main phase of the first superstorm, around the prereversal enhancement time (night of 7-8 November), prompt penetration of electric field was observed and the presence of equatorial ionospheric irregularities was detected from St. Croix, U.S. Virgin Islands (in the northern hemisphere) to Bahia Blanca, Argentina (in the southern hemisphere). The ionospheric sounding observations at Manaus indicate inhibition of prereversal enhancement on the nights of 9-10 and 10-11 November, possibly due to the disturbed thermospheric winds or disturbance electric fields. Virtually no phase fluctuations on the nights of 9-10 and 10-11 November were observed in the Latin American sector. During the daytime on 8 November, the vertical total electron content (VTEC) observations show a negative storm phase at Porto Alegre (Brazil) and Bahia Blanca (Argentina). Again during the daytime on 10 November, the VTEC observations show a negative storm phase from Brasilia (Brazil) to Bahia Blanca. These negative storm phases are associated with a decrease in the O/N2 ratio. During the daytime on 9 November, the VTEC observations show a positive storm phase extending from St. Croix to Porto Alegre, and again on 10 November, VTEC observations show a positive storm phase. These positive storm phases observed are possibly due to changes in large-scale wind circulation and an increase in the O/N2 ratio.

Sahai, Y.; Becker-Guedes, F.; Fagundes, P. R.; de Jesus, R.; de Abreu, A. J.; Paxton, L. J.; Goncharenko, L. P.; Brunini, C.; Gende, M.; Ferreira, A. S.; Lima, N. S.; Guarnieri, F. L.; Pillat, V. G.; Bittencourt, J. A.; Candido, C. M. N.

2009-03-01

255

Towards a discrete function theory in higher dimen-Fischer decomposition and Hardy spaces  

E-print Network

Towards a discrete function theory in higher dimen- sions: Fischer decomposition and Hardy spaces for construct- ing discrete function theories, such as basic algebraic structures, Fischer decomposition ukaehler@ua.pt In recent years one can observe an increasing interest in ob- taining discrete counterparts

Haase, Markus

256

Bit vector encoding via decomposition  

Microsoft Academic Search

The decomposition encoding of an n-bit vector V is an approach to the problem of how best to encode a bit vector under the constraints that this vector be encoded into blocks of t bits, and that access time for each bit of the original vector be constant, i.e. \\

Ralph D. Jeffords

1982-01-01

257

Decomposition patterns in problem solving  

Microsoft Academic Search

The paper develops a theory of biases in decision making. Discovering a strategy for solving a game is a complex problem that may be solved by decomposition; a player decomposing a problem into many simple sub-problems may easily identify the optimal solution to each sub-problem: however it is shown that even though all partial solutions are optimal, the solution to

Massimo Egidi

2003-01-01

258

Trade-Offs in Resource Allocation Among Moss Species Control Decomposition in Boreal Peatlands  

SciTech Connect

We separated the effects of plant species controls on decomposition rates from environmental controls in northern peatlands using a full factorial, reciprocal transplant experiment of eight dominant bryophytes in four distinct peatland types in boreal Alberta, Canada. Standard fractionation techniques as well as compound-specific pyrolysis molecular beam mass spectrometry were used to identify a biochemical mechanism underlying any interspecific differences in decomposition rates. We found that over a 3-year field incubation, individual moss species and not micro-environmental conditions controlled early stages of decomposition. Across species, Sphagnum mosses exhibited a trade-off in resource partitioning into metabolic and structural carbohydrates, a pattern that served as a strong predictor of litter decomposition. Decomposition rates showed a negative co-variation between species and their microtopographic position, as species that live in hummocks decomposed slowly but hummock microhabitats themselves corresponded to rapid decomposition rates. By forming litter that degrades slowly, hummock mosses appear to promote the maintenance of macropore structure in surface peat hummocks that aid in water retention. Many northern regions are experiencing rapid climate warming that is expected to accelerate the decomposition of large soil carbon pools stored within peatlands. However, our results suggest that some common peatland moss species form tissue that resists decomposition across a range of peatland environments, suggesting that moss resource allocation could stabilize peatland carbon losses under a changing climate.

Turetsky, M. R.; Crow, S. E.; Evans, R. J.; Vitt, D. H.; Wieder, R. K.

2008-01-01

259

9 CFR 354.131 - Decomposition.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Decomposition. 354.131 Section 354.131 Animals and Animal Products FOOD SAFETY...Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of rabbits...

2010-01-01

260

Finite element decomposition of the human neocortex  

E-print Network

The finite element decomposition of the human neocortex provides a structural information framework for the visualization and spatial organization of the neocortex at progressive levels of detail. The decomposition satisfies neuroanatomical...

Chow, Seeling

2012-06-07

261

Tremolite Decomposition and Water on Venus  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

262

9 CFR 381.93 - Decomposition.  

Code of Federal Regulations, 2010 CFR

...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...

2010-01-01

263

Radio-cesium accumulation during decomposition of leaf litter in a deciduous forest after the Fukushima NPP accident.  

NASA Astrophysics Data System (ADS)

Fukusima NPP accident contaminated vast area in eastern Japan with radio isotopes. Most of the area is covered by natural and plantation forest. The forest floor in deciduous forests, and canopy of evergreen forest were most contaminated by fall out. Radio-cesium is known to stay bioavailable in forest ecosystems for long time, and it is necessary to cut the cycling process to decontaminate the forest ecosystem. Ecological process to recycle radio-Cs in forest ecosystem should be studied to enhance decontamination of radio-Cs. Mushrooms show high concentration of Cs. Although mushroom biomass in a forest ecosystem is small, fungal mycelium in detritus and soil is large, thus fungi contain substantial amount of radio-Cs. It is well known that concentration of some nutrients, such as nitrogen and phosphorus, increase, whereas potassium decreases during the leaf litter decomposition. We observed radio-Cs concentration of leaf litter during decomposition on a forest floor where 134-Cs and 137-Cs of surface soil were 5,700, and 6,800 Bq/kg, respectively. We put 16 g (dry weight) of newly fallen mixed deciduous leaf litter (half of which was oak, Quercus serrata) into 25 cm x 25 cm litter bag (2 mm mesh size) in a deciduous forest about 50 km from Fukushima NPP. Fresh litter 137-Cs concentration was ca. 1,000 Bq/kg in December 2011. During the decomposition process on the forest floor, litter Cs increased exponentially and exceeded 10,000 Bq/kg after 6 months, indicating that Cs and K show contrasting dynamics during early decomposition phase. Increase in fungal biomass in the early stage of litter decomposition was observed. Therefore, this upward movement of Cs from humus and soil layer suggests fungal translocation of nutrients from outside of litter substrate. Retrieving the litter after 6 months can remove 18.0% of 134-Cs. Interaction between fungal species, grazing effect on fungi by fungivorous invertebrates will change the amount of translocation of radio-Cs from soil to decomposing litter.

Kaneko, Nobuhiro; Huang, Yao; Nakamori, Taizo; Tanaka, Yoichiro; Nonaka, Masanori

2013-04-01

264

In Situ Infrared Study of Catalytic Decomposition of NO  

SciTech Connect

The growing concerns for the environment and increasingly stringent standards for NO emission have presented a major challenge to control NO emmissions from electric utility plants and automobiles. Catalytic decomposition of NO is the most attractive approach for the control of NO emission for its simplicity. Successful development of an effective catalyst for NO decomposition will greatly decrease the equipment and operation cost of NO control. Due to lack of understanding of the mechanism of NO decomposition, efforts on the search of an effective catalyst have been unsuccesful. Scientific development of an effective catalyst requires fundamental understanding of the nature of active site, the rate-limiting step, and an approach to prolong the life of the catalyst. Research is proposed to study the reactivity of adsorbates for the direct NO decomposition and to investigate the feasibility of two novel approaches for improving catalyst activity and resistance to sintering. The first approach is the use of silanation to stabilize metal crystallites and supports for Cu-ZSM-5 and promoted Pt catalysts; the second is utilization of oxygen spillover and desorption to enhance NO decomposition activity. An innovative infrared reactor system will be used to observe and determine the dynamic behavior and the reactivity of adsorbates during NO decomposition, oxygen spillover, and silanation. A series of experiments including X-ray diffraction, temperature programmed desorption, temperature programmed reaction, X-ray photoelectron spectroscopy will be used to characterized the catalysts. The information obtained from this study will provide a scientific basis for developing an effective catalyst for the NO decomposition under practical flue gas conditions.

Cher-Dip Tan; Steven S.C. Chuang

1997-07-17

265

IN SITU INFRARED STUDY OF CATALYTIC DECOMPOSITION OF NO  

SciTech Connect

The growing concerns for the environment and increasingly stringent standards for NO emission have presented a major challenge to control NO emissions from electric utility plants and automobiles. Catalytic decomposition of NO is the most attractive approach for the control of NO emission for its simplicity. Successful development of an effective catalyst for NO decomposition will greatly decrease the equipment and operation cost of NO control. Due to lack of understanding of the mechanism of NO decomposition, efforts on the search of an effective catalyst have been unsuccessful. Scientific development of an effective catalyst requires fundamental understanding of the nature of active site, the rate-limiting step, and an approach to prolong the life of the catalyst. Research is proposed to study the reactivity of adsorbates for the direct NO decomposition and to investigate the feasibility of two novel approaches for improving catalyst activity and resistance to sintering. The first approach is the use of silanation to stabilize metal crystallites and supports for Cu-ZSM-5 and promoted Pt catalysts; the second is utilization of oxygen spillover and desorption to enhance NO decomposition activity. An innovative infrared reactor system will be used to observe and determine the dynamic behavior and the reactivity of adsorbates during NO decomposition, oxygen spillover, and silanation. A series of experiments including X-ray diffraction, temperature programmed desorption, temperature programmed reaction, X-ray photoelectron spectroscopy will be used to characterized the catalysts. The information obtained from this study will provide a scientific basis for developing an effective catalyst for the NO decomposition under practical flue gas conditions.

KHALID ALMUSAITEER; RAM KRISHNAMURTHY; STEVEN S.C. CHUANG

1998-08-18

266

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)

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.

Gerard, E.

1990-04-01

267

Biogeochemistry of Decomposition and Detrital Processing  

Microsoft Academic Search

Decomposition is a key ecological process that roughly balances net primary production in terrestrial ecosystems and is an essential process in resupplying nutrients to the plant community. Decomposition consists of three concurrent processes: communition or fragmentation, leaching of water-soluble compounds, and microbial catabolism. Decomposition can also be viewed as a sequential process, what Eijsackers and Zehnder (1990) compare to a

J. Sanderman; R. Amundson

2003-01-01

268

Regularized Statistical Material Decomposition in Medical Imaging  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . . . 27 5. Water-Fat Decomposition from MR k-space Data using Regularized Field Map . . . . . . . . . . . . . . . . . . 12 4. Water-Fat Decomposition with Regularized Field Map Estimation . . 14 4.1 Introduction. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Water-Fat Decomposition

Fessler, Jeffrey A.

269

Imposed-Functional Dependencies Inducing Horizontal Decompositions  

Microsoft Academic Search

A new decomposition theory for functional dependencies in the Relational Database Model is given. It uses a horizontal decomposition of a relation into two disjoint subrelations, of which the union is the given relation. This horizontal decomposition is based on a new constraint, the imposed-functional dependency (ifd), of which the conditional-functional dependency (cfd), introduced in a previous work, is a

Paul De Bra

1985-01-01

270

Identifying and Investigating Evolution Type Decomposition Weaknesses  

E-print Network

belong to the same decomposition elements regarding the development group and deployment group to the same decomposition element if they 1. belong to the same subsystem (subsystem decomposition) 2. are developed by the same group of developers (development group de- composition) 3. are deployed to the same

van Vliet, Hans

271

INTERACTIVE SIMULATION OF FIRE, BURN AND DECOMPOSITION  

E-print Network

, decomposition and deformation of burning solids, and rigid body simulation of the residue. Simulators for everyINTERACTIVE 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

Keyser, John

272

Symmetry of Attractors and the KarhunenLo`eve Decomposition  

E-print Network

Symmetry of Attractors and the Karhunen­Lo`eve Decomposition Michael Dellnitz Department in the time­average of an appropriate observable such as the intensity of transmitted light in the Faraday] have investigated the Faraday surface wave model, looking for indications of pattern on average

Nicol, Matthew

273

Convexity Rule for Shape Decomposition Based on Discrete Contour Evolution  

Microsoft Academic Search

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

Longin Jan Latecki; Rolf Lakämper

1999-01-01

274

Decomposition of Gas Phase Formaldehyde by Plasma Discharge.  

National Technical Information Service (NTIS)

Formaldehyde decomposition in a silent electrical discharge is shown to occur and it is demonstrated that the basis for the decomposition is not oxidation produced by ozone in the plasma. Keywords include: Plasma decomposition; Formaldehyde decomposition;...

E. J. Clothiaux

1985-01-01

275

Crop residue decomposition in Minnesota biochar amended plots  

NASA Astrophysics Data System (ADS)

Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different feedstocks and pyrolysis platforms prior to the start of this study. Litterbags containing wheat straw material were buried below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a non-charred wood pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Though no significant impacts were observed with field-weathered biochars, effective soil management may yet have to account for repeat applications of biochar.

Weyers, S. L.; Spokas, K. A.

2014-02-01

276

Effect of polar surfaces on decomposition of molecular materials.  

PubMed

We report polar instability in molecular materials. Polarization-induced explosive decomposition in molecular crystals is explored with an illustrative example of two crystalline polymorphs of HMX, an important energetic material. We establish that the presence of a polar surface in ?-HMX has fundamental implications for material stability and overall chemical behavior. A comparative quantum-chemical analysis of major decomposition mechanisms in polar ?-HMX and nonpolar ?-HMX discovered a dramatic difference in dominating dissociation reactions, activation barriers, and reaction rates. The presence of charge on the polar ?-HMX surface alters chemical mechanisms and effectively triggers decomposition simultaneously through several channels with significantly reduced activation barriers. This results in much faster decomposition chemistry and in higher chemical reactivity of ?-HMX phase relatively to ?-HMX phase. We predict decomposition mechanisms and their activation barriers in condensed ?-HMX phase, sensitivity of which happens to be comparable to primary explosives. We suggest that the observed trend among polymorphs is a manifestation of polar instability phenomena, and hence similar processes are likely to take place in all polar molecular crystals. PMID:25170566

Kuklja, Maija M; Tsyshevsky, Roman V; Sharia, Onise

2014-09-24

277

Isothermal Decomposition of Ferrite in a High-Nitrogen, Nickel-Free Duplex Stainless Steel  

NASA Astrophysics Data System (ADS)

The formation and crystallography of second phases during isothermal decomposition of ferrite (?) in a high-nitrogen, nickel-free duplex stainless steel was examined by means of transmission electron microscopy (TEM). At an early stage of aging, the decomposition of ? started along the ?/ ? phase boundaries where sigma ( ?) phase and secondary austenite ( ? 2) precipitated in the form of an alternating lamellar structure. The combined analyses based on the simulation of diffraction patterns and stereographic projection have shown that most of the ? phase was related to the ? 2 by the following relation: (111)_{? } allel (001)_{? } and [10bar{1}]_{? } allel [110]_{? } . The intergranular and intragranular precipitation of Cr2N with trigonal structure were identified, and the orientation relationships (ORs) with ? and ? matrix could be expressed as left( {110} right)_{? } allel left( {0001} right)_{{{text{Cr}}2 {text{N}}}} , left[ {bar{1}11} right]_{? } allel [bar{1}100]_{{{text{Cr}}2 {text{N}}}} ; (111)_{? } allel (0001)_{{{text{Cr}}2 {text{N}}}} , and left[ {bar{1}10} right]_{? } allel left[ {bar{1}100} right]_{{{text{Cr}}2 {text{N}}}} , respectively. The precipitation of intermetallic ? phase was also observed inside the ? matrix, and they obeyed the cube-on-cube OR with the ? matrix. Prolonged aging changed both the structure of matrix and the distribution of second phases. The ? 2, formed by decomposition of ?, became unstable because of the depletion of mainly N accompanied by the formation of Cr2N, and it transformed into martensite after subsequent cooling. As a result, the microstructure of the decomposed ? region was composed of three kinds of precipitates (intermetallic ?, ?, and Cr2N) embedded in lath martensite.

Lee, Tae-Ho; Ha, Heon-Young; Hwang, Byoungchul; Kim, Sung-Joon

2012-03-01

278

Decomposition pathways in age hardening of Ti-Al-N films  

NASA Astrophysics Data System (ADS)

The ability to increase the thermal stability of protective coatings under work load gives rise to scientific and industrial interest in age hardening of complex nitride coating systems such as ceramic-like Ti1-xAlxN. However, the decomposition pathway of these systems from single-phase cubic to the thermodynamically stable binary nitrides (cubic TiN and wurtzite AlN), which are essential for age hardening, are not yet fully understood. In particular, the role of decomposition kinetics still requires more detailed investigation. In the present work, the combined effect of annealing time and temperature upon the nano-structural development of Ti0.46Al0.54N thin films is studied, with a thermal exposure of either 1 min or 120 min in 100 °C steps from 500 °C to 1400 °C. The impact of chemical changes at the atomic scale on the development of micro-strain and mechanical properties is studied by post-annealing investigations using X-ray diffraction, nanoindentation, 3D-atom probe tomography and high-resolution transmission electron microscopy. The results clearly demonstrate that the spinodal decomposition process, triggering the increase of micro-strain and hardness, although taking place throughout the entire volume, is enhanced at high diffusivity paths such as grain or column boundaries and followed within the grains. Ab initio calculations further show that the early stages of wurtzite AlN precipitation are connected with increased strain formation, which is in excellent agreement with experimental observations.

Rachbauer, R.; Massl, S.; Stergar, E.; Holec, D.; Kiener, D.; Keckes, J.; Patscheider, J.; Stiefel, M.; Leitner, H.; Mayrhofer, P. H.

2011-07-01

279

Meson Mass Decomposition  

E-print Network

Hadron masses can be decomposed as a sum of components which are defined through hadronic matrix elements of QCD operators. The components consist of the quark mass term, the quark energy term, the glue energy term and the trace anomaly term. We calculate these components of mesons with lattice QCD for the first time. The calculation is carried out with overlap fermion on $2+1$ flavor domain-wall fermion gauge configurations. We confirm that $\\sim 50\\%$ of the light pion mass comes from the quark mass and $\\sim 10\\%$ comes from the quark energy, whereas, the contributions are found to be the other way around for the $\\rho$ mass. The combined glue components contribute $\\sim 40 - 50\\%$ for both mesons. It is interesting to observe that the quark mass contribution to the mass of the vector meson is almost linear in quark mass over a large quark mass region below the charm quark mass. For heavy mesons, the quark mass term dominates the masses, while the contribution from the glue components is about $400\\sim500$...

Yang, Yi-Bo; Draper, Terrence; Gong, Ming; Liu, Keh-Fei; Liu, Zhaofeng; Ma, Jian-Ping

2014-01-01

280

CaII K interstellar observations towards early-type disc and halo stars, abundances and distances of intermediate- and high-velocity clouds  

NASA Astrophysics Data System (ADS)

We present CaII K (?air = 3933.661Å) interstellar observations towards 20 early-type stars, to place lower distance limits to intermediate- and high-velocity clouds (IHVCs) in their lines of sight. The spectra are also employed to estimate the Ca abundance in the low-velocity gas towards these objects, when combined with Leiden-Dwingeloo 21-cm HI survey data of spatial resolution . Nine of the stars, which lie towards IHVC complexes H, K and gp, were observed with the intermediate dispersion spectrograph on the Isaac Newton Telescope at a resolution R = ?/?? of 9000 (~33kms-1) and signal-to-noise ratio (S/N) per pixel of 75-140. A further nine objects were observed with the Utrecht Echelle Spectrograph on the William Herschel Telescope at R = 40000 (~7.5kms-1) and S/N per pixel of 10-25. Finally, two objects were observed in both CaII K and NaI D lines using the 2D COUDÉ spectrograph on the McDonald 2.7-m telescope at R = 35000 (~8.5 kms-1). The abundance of CaII K {log10(A) = log10[N(CaII K)]-log10[N(HI)]} plotted against HI column density for the objects in the current sample with heights above the Galactic plane (z) exceeding 1000pc is found to obey the Wakker & Mathis (2000) relation. Also, the reduced column density of CaII K as function of z is consistent with the larger sample taken from Smoker et al. (2003). Higher S/N observations than those previously taken towards HVC complex H stars HD13256 and HILT 190 reinforce the assertion that this lies at a distance exceeding 4000pc. No obvious absorption is detected in observations of ALS10407 and HD357657 towards IVC complex gp. The latter star has a spectroscopically estimated distance of ~2040pc, although this was derived assuming the star lies on the main sequence and without any reddening correction being applied. Finally, no CaII K absorption is detected towards two stars along the line of sight to complex K, namely PG1610+529 and PG1710+490. The latter is at a distance of ~700pc, hence placing a lower distance limit to this complex, where previously only an upper distance limit of 6800pc was available.

Smoker, J. V.; Lynn, B. B.; Christian, D. J.; Keenan, F. P.

2006-07-01

281

Thermal Decomposition of Furan Generates Propargyl Radicals  

SciTech Connect

The thermal decomposition of furan has been studied by a 1 mm x 2 cm tubular silicon carbide reactor, C{sub 4}H{sub 4}O + {Delta} {yields} 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 {micro}s) 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.

Vasiliou, A.; Nimlos, M. R.; Daily, J. W.; Ellison, G. B.

2009-07-01

282

Isospin fluctuations in spinodal decomposition  

SciTech Connect

We study the isospin dynamics in fragment formation within the framework of an analytical model based on the spinodal decomposition scenario. We calculate the probability to obtain fragments with given charge and neutron number, focussing on the derivation of the width of the isotopic distributions. Within our approach this is determined by the dispersion of N/Z among the leading unstable modes, due to the competition between Coulomb and symmetry energy effects, and by isovectorlike fluctuations present in the matter that undergoes the spinodal decomposition. Hence the widths exhibit a clear dependence on the properties of the equation of state. By comparing two systems with different values of the charge asymmetry we find that the isotopic distributions reproduce an isoscaling relationship.

Colonna, M.; Matera, F. [Laboratori Nazionali del Sud, Via S. Sofia 44, I-95123 Catania (Italy); Dipartimento di Fisica, Universita degli Studi di Firenze and Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, Via G. Sansone 1, I-50019 Sesto F. no, Florence (Italy)

2005-06-01

283

Spectral decomposition of broad-line agns and host galaxies  

SciTech Connect

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.

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

284

Thermocatalytic decomposition of vulcanized rubber  

E-print Network

. First, to be econ rubber as fuel must compete with ordinary fuels, such as natural gas, wood, and coal. Should the cost of energy continue to rise, there likely will be an increased interest in using TDF. Unfortunately the coal price is expected (1... still employed subsidy programs. Concerning Category (3), most attempts to convert tire rubber into chemicals have involved pyrolysis, the thermal decomposition of rubber at high temperature, or catalysis-assisted pyrolysis. In the last 30 years, many...

Qin, Feng

2007-04-25

285

Decomposition kinetics of plutonium hydride  

Microsoft Academic Search

Kinetic data for decomposition of PuH⁠ââ provides insight into a possible mechanism for the hydriding and dehydriding reactions of plutonium. The fact that the rate of the hydriding reaction, K\\/sub H\\/, is proportional to P¹² and the rate of the dehydriding process, K\\/sub D\\/, is inversely proportional to P¹² suggests that the forward and reverse reactions proceed by opposite

J. M. Haschke; J. L. Stakebake

1979-01-01

286

Empirical Mode Decomposition - an introduction  

Microsoft Academic Search

Due to external stimuli, biomedical signals are in general non-linear and non-stationary. Empirical Mode Decomposition in conjunction with a Hilbert spectral transform, together called Hilbert-Huang Transform, is ideally suited to extract essential components which are characteristic of the underlying biological or physiological processes. The method is fully adaptive and generates the basis to represent the data solely from these data

A. Zeiler; R. Faltermeier; I. R. Keck; A. M. Tome?; C. G. Puntonet; E. W. Lang

2010-01-01

287

Decomposition Studies of Tetraphenylborate Slurries  

SciTech Connect

This report details the decomposition of aqueous (K,Na) slurries in concentrated salt solutions using a more complete candidate catalyst recipe, extended testing temperatures (40-70 degrees C) and test durations of approximately 1500 hours (9 weeks). This study uses recently developed High-Pressure Liquid Chromatography (HPLC) methods for analysis of tetraphenylborate (TPB-), triphenylborane (3PB) and diphenylborinic acid (2PB). All of the present tests involve non-radioactive simulants and do not include investigations of radiolysis effects.

Crawford, C.L. [Westinghouse Savannah River Company, AIKEN, SC (United States)

1997-05-06

288

Phlogopite Decomposition, Water, and Venus  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

289

Steerable filters for early vision, image analysis, and wavelet decomposition  

Microsoft Academic Search

An efficient architecture is presented to synthesize filters of arbitrary orientations from linear combinations of basis filters, allowing one to adaptively `steer' a filter to any orientation, and to determine analytically the filter output as a function of orientation. The authors show how to design and steer filters, and present examples of their use in several tasks: the analysis of

W. T. Freeman; E. H. Adelson

1990-01-01

290

Potential role of gas hydrate decomposition in generating submarine slope failures: Chapter 12  

USGS Publications Warehouse

Gas hydrate decomposition is hypothesized to be a factor in generating weakness in continental margin sediments that may help explain some of the observed patterns of continental margin sediment instability. The processes associated with formation and decomposition of gas hydrate can cause the strengthening of sediments in which gas hydrate grow and the weakening of sediments in which gas hydrate decomposes. The weakened sediments may form horizons along which the potential for sediment failure is increased. While a causal relationship between slope failures and gas hydrate decomposition has not been proven, a number of empirical observations support their potential connection.

Pauli, Charles K.; mUssler, William III; Dillon, William P.

2003-01-01

291

The effect of body size on the rate of decomposition in a temperate region of South Africa.  

PubMed

Forensic anthropologists rely on the state of decomposition of a body to estimate the post-mortem-interval (PMI) which provides information about the natural events and environmental forces that could have affected the remains after death. Various factors are known to influence the rate of decomposition, among them temperature, rainfall and exposure of the body. However, conflicting reports appear in the literature on the effect of body size on the rate of decay. The aim of this project was to compare decomposition rates of large pigs (Sus scrofa; 60-90 kg), with that of small pigs (<35 kg), to assess the influence of body size on decomposition rates. For the decomposition rates of small pigs, 15 piglets were assessed three times per week over a period of three months during spring and early summer. Data collection was conducted until complete skeletonization occurred. Stages of decomposition were scored according to separate categories for each anatomical region, and the point values for each region were added to determine the total body score (TBS), which represents the overall stage of decomposition for each pig. For the large pigs, data of 15 pigs were used. Scatter plots illustrating the relationships between TBS and PMI as well as TBS and accumulated degree days (ADD) were used to assess the pattern of decomposition and to compare decomposition rates between small and large pigs. Results indicated that rapid decomposition occurs during the early stages of decomposition for both samples. Large pigs showed a plateau phase in the course of advanced stages of decomposition, during which decomposition was minimal. A similar, but much shorter plateau was reached by small pigs of >20 kg at a PMI of 20-25 days, after which decomposition commenced swiftly. This was in contrast to the small pigs of <20 kg, which showed no plateau phase and their decomposition rates were swift throughout the duration of the study. Overall, small pigs decomposed 2.82 times faster than large pigs, indicating that body size does have an effect on the rate of decomposition. PMID:23890647

Sutherland, A; Myburgh, J; Steyn, M; Becker, P J

2013-09-10

292

Elevated atmospheric carbon dioxide effects on cotton plant residue decomposition  

SciTech Connect

Assessing the impact of elevated atmospheric CO{sub 2} concentration on the global environment is hampered due to a lack of understanding of global C cycling. Carbon fixed within plant biomass ultimately enters the soil via plant residues, but the effects of elevated-CO{sub 2}-grown plant material on decomposition rates and long-term soil C storage are unknown. The objective of this study was to determine the decomposition rate of plant residues grown under an elevated CO{sub 2} environment as affected by soil type. Cotton (Gossypium hirsutum L. `Delta Pine 77`) samples were collected from a free-air CO{sub 2} enrichment (550 {mu}L L{sup -1}) experiment. The plant residues were incubated under ambient CO{sub 2} conditions to determine decomposition rates of leaves, stems, and roots and potential N and P mineralization-immobilization in three soil series. No significant difference was observed between plant residue grown under CO{sub 2} enrichment vs. ambient CO{sub 2} conditions for soil respiration or P mineralization-immobilization. Significantly greater net N immobilization was observed during the incubation in all soil types for plant residue grown at elevated CO{sub 2}. These results indicate that while decomposition of plant residue may not be reduced by CO{sub 2} enrichment, N dynamics may be markedly changed. 32 refs., 5 figs., 3 tabs.

Torbert, H.A. [USDA-ARS Blackland, Temple. TX (United States); Prior, S.A.; Rogers, H.H. [USDA-ARS National Soil Dynamics Lab., Auburn, AL (United States)

1995-09-01

293

Noisy matrix decomposition via convex relaxation: Optimal rates in high dimensions  

E-print Network

We analyze a class of estimators based on convex relaxation for solving high-dimensional matrix decomposition problems. The observations are noisy realizations of a linear transformation [bar through "X" symbol] of the sum ...

Agarwal, Alekh

294

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

PubMed

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

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

295

A new seismogeodetic approach applied to GPS and accelerometer observations of the 2012 Brawley seismic swarm: Implications for earthquake early warning  

NASA Astrophysics Data System (ADS)

The 26 August 2012 Brawley seismic swarm of hundreds of events ranging from M1.4 to M5.5 in the Salton Trough, California provides a unique data set to investigate a new seismogeodetic approach that combines Global Positioning System (GPS) and accelerometer observations to estimate displacement and velocity waveforms. First in simulated real-time mode, we analyzed 1-5 Hz GPS data collected by 17 stations fully encircling the swarm zone at near-source distances up to about 40 km using precise point positioning with ambiguity resolution (PPP-AR). We used a reference network of North American GPS stations well outside the region of deformation to estimate fractional-cycle biases and satellite clock parameters, which were then combined with ultrarapid orbits from the International GNSS Service to estimate positions during the Brawley seismic swarm. Next, we estimated seismogeodetic displacements and velocities from GPS phase and pseudorange observations and 100-200 Hz accelerations collected at three pairs of GPS and seismic stations in close proximity using a new tightly coupled Kalman filter approach as an extension of the PPP-AR process. We can clearly discern body waves in the velocity waveforms, including P-wave arrivals not detectable with the GPS-only approach for earthquake magnitudes as low as Mw 4.6 and significant static offsets for magnitudes as low as Mw 5.4. Our study shows that GPS networks upgraded with strong motion accelerometers can provide new information for improved understanding of the earthquake rupture process and be of critical value in creating a robust early warning system for any earthquake of societal significance.

Geng, Jianghui; Bock, Yehuda; Melgar, Diego; Crowell, Brendan W.; Haase, Jennifer S.

2013-07-01

296

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

PubMed Central

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

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

2013-01-01

297

Seasonal variation of carcass decomposition and gravesoil chemistry in a cold (Dfa) climate.  

PubMed

It is well known that temperature significantly affects corpse decomposition. Yet relatively few taphonomy studies investigate the effects of seasonality on decomposition. Here, we propose the use of the Köppen-Geiger climate classification system and describe the decomposition of swine (Sus scrofa domesticus) carcasses during the summer and winter near Lincoln, Nebraska, USA. Decomposition was scored, and gravesoil chemistry (total carbon, total nitrogen, ninhydrin-reactive nitrogen, ammonium, nitrate, and soil pH) was assessed. Gross carcass decomposition in summer was three to seven times greater than in winter. Initial significant changes in gravesoil chemistry occurred following approximately 320 accumulated degree days, regardless of season. Furthermore, significant (p < 0.05) correlations were observed between ammonium and pH (positive correlation) and between nitrate and pH (negative correlation). We hope that future decomposition studies employ the Köppen-Geiger climate classification system to understand the seasonality of corpse decomposition, to validate taphonomic methods, and to facilitate cross-climate comparisons of carcass decomposition. PMID:23822087

Meyer, Jessica; Anderson, Brianna; Carter, David O

2013-09-01

298

Downregulation of Early Ionotrophic Glutamate Receptor Subunit Developmental Expression as a Mechanism for Observed Plasticity Deficits Following Gestational Exposure to Benzo(a)pyrene  

PubMed Central

The focus of this study was to characterize the impact of gestational exposure to benzo(a)pyrene, [B(a)P] on modulation of glutamate receptor subunit expression that is critical for the maintenance of synaptic plasticity mechanisms during hippocampal or cortical development in offspring. Previous studies have demonstrated that hippocampal and/or cortical synaptic plasticity (as measured by long-term potentiation and S1-cortex spontaneous/evoked neuronal activity) and learning behavior (as measured by fixed-ratio performance operant testing) is significantly impaired in polycyclic aromatic or halogenated aromatic hydrocarbon-exposed offspring as compared to controls. These previous studies have also revealed that brain to body weight ratios are greater in exposed offspring relative to controls indicative of intrauterine growth retardation which has been shown to manifest as low birth weight in offspring. Recent epidemiological studies have identified an effect of prenatal exposure to airborne polycyclic aromatic hydrocarbons on neurodevelopment in the first 3 Years of life among inner-city children (Perera et al., 2006). The present study utilizes a well-characterized animal model to test the hypothesis that gestational exposure to B(a)P causes dysregulation of developmental ionotropic glutamate receptor subunit expression, namely the N-methyl-D-aspartate receptor (NMDAR) and ?-amino-3-hydroxy-5-methyl-4-isoxazole-propionate receptor (AMPAR) both critical to the expression of synaptic plasticity mechanisms. To mechanistically ascertain the basis of B(a)P-induced plasticity perturbations, timed pregnant Long-Evans rats were exposed in an oral subacute exposure regimen to 0, 25 and 150µg/kg BW B(a)P on gestation days 14–17. The first sub-hypothesis tested whether gestational exposure to B(a)P would result in significant disposition in offspring. The second sub-hypothesis tested whether gestational exposure to B(a)P would result in downregulation of early developmental expression of NMDA and AMPA receptor subunits in the hippocampus of offspring as well as in primary neuronal cultures. The results of these studies revealed significant: 1) disposition to the hippocampus and cortex, 2) down-regulation of developmental glutamate receptor mRNA and protein subunit expression and 3) voltage-dependent decreases in the amplitude of inward currents at negative potentials in B(a)P-treated cortical neuronal membranes. These results suggest that plasticity and behavioral deficits produced as a result of gestational B(a)P exposure are at least, in part, a result of down-regulation of early developmental glutamate receptor subunit expression and function at a time when excitatory synapses are being formed for the first time in the developing central nervous system. The results also predict that in B(a)P-exposed offspring with reduced early glutamate receptor subunit expression, a parallel deficit in behaviors that depend on normal hippocampal or cortical functioning will be observed and that these deficits will be present throughout life. PMID:17606297

Brown, La’Nissa A.; Khoshbouei, Habibeh; Goodwin, J. Shawn; Irvin-Wilson, Charletha V.; Ramesh, Aramandla; Sheng, Liu; McCallister, Monique M.; Jiang, George C. T.; Aschner, Michael; Hood, Darryl B.

2007-01-01

299

Conductimetric determination of decomposition of silicate melts  

NASA Technical Reports Server (NTRS)

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.

Kroeger, C.; Lieck, K.

1986-01-01

300

Linking early Earth magma ocean crystallization and overturn with observed large low-shear-velocity provinces (LLSVPs) and short-lived radioisotopic measurements in Archean rocks  

NASA Astrophysics Data System (ADS)

Motivated by the well-characterized discrepancy between measurements of 142Nd in chondrites and those in Earth rocks (e.g.,[1][2]) in addition to recent measurements of Archean rocks with anomalous 142Nd and 182W (e.g.,[3][4][5]), we model the crystallization and overturn of a terrestrial chondritic magma ocean, and track the isotopic reservoirs that may result. Following magma ocean solidification, solid-state overturn occurs because solidification produces a gravitationally unstable configuration where the last cumulates to solidify are densest and also enriched in incompatible elements. As suggested by [1][2], these originally shallow cumulates that, following overturn, would now reside near the core-mantle boundary are tantalizing targets for the hypothesized hidden reservoir(s) of incompatible elements. These last, dense, enriched cumulates may have evolved negative 142Nd and 182W isotopic anomalies, while cumulates that form earlier and deeper in the magma ocean would likely be poor in incompatible elements and have evolved complementary positive isotopic anomalies. Because crystal - liquid partition coefficients of Sm, Nd, Hf, and W in nucleating mantle phases are poorly constrained and vary over orders of magnitude, we use a Monte Carlo approach to cover the parameter space of reported partition coefficients. Although data are limited, Archean rocks appear to show a non-linear trend between age and 142Nd and 182W, suggesting inefficient heterogeneous mixing of some of the early enriched reservoir (EER or late stage cumulates) back into the early depleted reservoir (EDR or deeper cumulates) during or after overturn, also first suggested by [1][2]. To account for this, we model various mixing scenarios using post-overturn mantle stratigraphy. Additionally, because 142Nd and 182W are decay products of short-lived radioisotopes, the timing of magma ocean crystallization is critical to producing a modern day mantle consistent with measured compositions. We therefore iterate through time to determine the statistically most likely time of the last major mantle-melting event. Consistent with [2], we argue that the EER is not hidden but is instead the seismologically observed large low-shear-velocity provinces (LLSVPs), or the D'' region, and the ultra low velocity zones (ULVZs) are dense, iron-rich silicon-poor melts of the LLSVPs. Given this, the isotopic reservoirs produced by our models must mix such that the EER remaining after mixing is the same volume as the LLSVPs, or 2% of the mantle (e.g., [6][7]). Approximately two-thirds our run results are "successful" given known partition coefficients, and so our results suggest that this model is viable: magma ocean fractional solidification can produce mantle reservoirs consistent with isotopic compositions observed in some rocks, and can produce a dense lower mantle layer consistent in longevity and volume to the LLSVPs. [1]Boyet and Carlson,2005,Science,309(5743),576-81.[2]Carlson and Boyet,2008,Phil. Trans. R. Soc. A,366(1883),4077-103. [3]Willbold et al.,2011,Nature,477(7363), 195-8. [4]Touboul et al.,2012,Science,335(6072),1065-9. [5]Rizo et al.,Nature,491(7422),96-100. [6]Burke et al.,2008,EPSL,265(1-2),49-60. [7]Hernlund and Houser,2008,EPSL,265(3-4),423-37.

Brown, S. M.; Elkins-Tanton, L. T.; Walker, R. J.

2013-12-01

301

APEX/SABOCA observations of small-scale structure of infrared-dark clouds . I. Early evolutionary stages of star-forming cores  

NASA Astrophysics Data System (ADS)

Infrared-dark clouds (IRDCs) harbor the early phases of cluster and high-mass star formation and are comprised of cold (~20 K), dense (n > 104 cm-3) gas. The spectral energy distribution (SED) of IRDCs is dominated by the far-infrared and millimeter wavelength regime, and our initial Herschel study examined IRDCs at the peak of the SED with high angular resolution. Here we present a follow-up study using the SABOCA instrument on APEX which delivers 7.8? angular resolution at 350 ?m, matching the resolution we achieved with Herschel/PACS, and allowing us to characterize substructure on ~0.1 pc scales. Our sample of 11 nearby IRDCs are a mix of filamentary and clumpy morphologies, and the filamentary clouds show significant hierarchical structure, while the clumpy IRDCs exhibit little hierarchical structure. All IRDCs, regardless of morphology, have about 14% of their total mass in small scale core-like structures which roughly follow a trend of constant volume density over all size scales. Out of the 89 protostellar cores we identified in this sample with Herschel, we recover 40 of the brightest and re-fit their SEDs and find their properties agree fairly well with our previous estimates (? T ? ~ 19 K). We detect a new population of "cold cores" which have no 70 ?m counterpart, but are 100 and 160 ?m-bright, with colder temperatures (? T ? ~ 16 K). This latter population, along with SABOCA-only detections, are predominantly low-mass objects, but their evolutionary diagnostics are consistent with the earliest starless or prestellar phase of cores in IRDCs. Based on observations carried out with the Atacama Pathfinder Experiment (APEX). APEX is a collaboration between Max Planck Institut für Radioastronomie (MPIfR), Onsala Space Observatory (OSO), and the European Southern Observatory (ESO).Appendices are available in electronic form at http://www.aanda.org

Ragan, Sarah E.; Henning, Thomas; Beuther, Henrik

2013-11-01

302

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

NASA Technical Reports Server (NTRS)

We analyze the spectral energy distributions (SEDs) of Lyman break galaxies . (LBGs) at z approx = 1-3 selected using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) UVIS channel filters. These HST /WFC3 obse,rvations cover about 50 arcmin2 in the GOODS-South field as a part of the WFC3 Early Release Science program. These LBGs at z approx = 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 f3 is redder than at high redshift (z > 3), where LBGs are less dusty; (3) on average, LBGs at .z approx = 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 1a uncertainties. This could imply that identical dropout selection technique, at all. redshifts, find physically similar galaxies; and (4) the stellar masses of these LBGs are directly proportional to their UV luminosities with a logarithmic slope of approx 0.46, and star-formation rates are proportional to their stellar masses with a logarithmic slope of approx 0.90. These relations hold true - within luminosities probed in this study - for LBGs from z approx = 1.5 to 5. The star-forming galaxies selected using other color-based techniques show similar correlations at z approx = 2, but to avoid any selection biases, and for direct comparison with LBGs at z > 3, a true Lyman break selection at z approx = 2 is essential. The future HST UV surveys,. both wider and deeper, covering a large luminosity range are important to better understand LBG properties, and their evolution.

Hathi, N. P.; Cohen, S. H.; Ryan, R. E., Jr.; Finkelstein, S. L.; McCarthy, P. J.; Windhorst, R. A.; Yan, H.; Koekemoer, A. M.; Rutkowski, M. J.; OConnell, R. W.; Straughn, A. N.; Balick, B.; Bond, H. E.; Calzetti, D.; Disney, M. J.; Dopita, M. A.; Frogel, Jay A.; Hall, D. N. B.; Holtzman, J. A.; Kimble, R. A.; Paresce, F.; Saha, A.; Silk, J. I.; Tauger, J. T.; Young, E. T.

2012-01-01

303

SPECTROSCOPIC OBSERVATIONS OF SN 2012fr: A LUMINOUS, NORMAL TYPE Ia SUPERNOVA WITH EARLY HIGH-VELOCITY FEATURES AND A LATE VELOCITY PLATEAU  

SciTech Connect

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 {lambda}6355 line that can be cleanly decoupled from the lower velocity ''photospheric'' component. This Si II {lambda}6355 HVF fades by phase -5; subsequently, the photospheric component exhibits a very narrow velocity width and remains at a nearly constant velocity of {approx}12,000 km s{sup -1} until at least five weeks after maximum brightness. The Ca II infrared triplet exhibits similar evidence for both a photospheric component at v Almost-Equal-To 12,000 km s{sup -1} with narrow line width and long velocity plateau, as well as an HVF beginning at v Almost-Equal-To 31,000 km s{sup -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.

Childress, M. J.; Scalzo, R. A.; Sim, S. A.; Tucker, B. E.; Yuan, F.; Schmidt, B. P. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Cenko, S. B.; Filippenko, A. V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Silverman, J. M. [Department of Astronomy, University of Texas, Austin, TX 78712-0259 (United States); Contreras, C.; Hsiao, E. Y.; Phillips, M.; Morrell, N. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Jha, S. W.; McCully, C. [Department of Physics and Astronomy, Rutgers, State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Anderson, J. P.; De Jaeger, T.; Forster, F. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Benetti, S. [INAF Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy); Bufano, F., E-mail: mjc@mso.anu.edu.au [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); and others

2013-06-10

304

Decomposition methods in turbulence research  

NASA Astrophysics Data System (ADS)

Nowadays we have the dynamical velocity vector field of turbulent flow at our disposal coming thanks advances of either mathematical simulation (DNS) or of experiment (time-resolved PIV). Unfortunately there is no standard method for analysis of such data describing complicated extended dynamical systems, which is characterized by excessive number of degrees of freedom. An overview of candidate methods convenient to spatiotemporal analysis for such systems is to be presented. Special attention will be paid to energetic methods including Proper Orthogonal Decomposition (POD) in regular and snapshot variants as well as the Bi-Orthogonal Decomposition (BOD) for joint space-time analysis. Then, stability analysis using Principal Oscillation Patterns (POPs) will be introduced. Finally, the Independent Component Analysis (ICA) method will be proposed for detection of coherent structures in turbulent flow-field defined by time-dependent velocity vector field. Principle and some practical aspects of the methods are to be shown. Special attention is to be paid to physical interpretation of outputs of the methods listed above.

Uruba, Václav

2012-04-01

305

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...

306

Mechanism change in hot dense liquid nitromethane decomposition: ReaxFF molecular dynamics simulations  

NASA Astrophysics Data System (ADS)

The decomposition mechanism of hot liquid nitromethane (NM) at various compressions and temperatures was studied using reactive force field (ReaxFF) molecular dynamics simulations. A competition between two initial thermal decomposition schemes is observed, depending on compression. At low densities unimolecular C-N bond cleavage is the dominant route, whereas when approaching Chapman-Jouget detonation conditions the dominant mechanism switches to the formation of CH3NO fragment. The change in decomposition mechanism of hot liquid NM leads to different kinetic and energetic behavior and products distribution.

Rom, Naomi; Zybin, Sergey; van Duin, Adri; Goddard, William; Zeiri, Yehuda; Katz, Gil; Kosloff, Ronnie

2011-06-01

307

Singular-value decomposition of a tomosynthesis system  

PubMed Central

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

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

2010-01-01

308

DECOMPOSITIONAL ODOR ANALYSIS DATABASE - PHASE I  

Microsoft Academic Search

This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), describes the development of the Decompositional Odor Analysis (D.O.A.) Database and seeks to establish the chemical basis for canine's scenting ability when detecting human remains. This database is composed of chemicals that are liberated during the decompositional process from buried human remains. This 'living' database currently spans the

Arpad A. Vass; Rob R. Smith; Cyril V. Thompson; Michael N. Burnett; Dennis A. Wolf; Jennifer A. Synstelien; Brian A. Eckenrode

309

Factors affecting decomposition and Diptera colonization  

Microsoft Academic Search

Understanding the process of corpse decomposition is basic to establishing the postmortem interval (PMI) in any death investigation even using insect evidence. The sequence of postmortem changes in soft tissues usually gives an idea of how long an individual has been dead. However, modification of the decomposition process can considerably alter the estimate of the time of death. A body

Carlo Pietro Campobasso; Giancarlo Di Vella; Francesco Introna

2001-01-01

310

Innovative Methodology Decomposition of Surface EMG Signals  

E-print Network

Innovative Methodology Decomposition of Surface EMG Signals Carlo J. De Luca,1,3 Alexander Adam,1, Robert Wotiz, L. Donald Gilmore, and S. Hamid Nawab. Decomposition of surface EMG signals. J Neurophysiol for decomposing surface electromyographic (sEMG) signals into the constituent motor unit (MU) action potential

De Luca, Carlo J.

311

ATOMIC DECOMPOSITIONS AND OPERATORS ON HARDY SPACES  

E-print Network

ATOMIC DECOMPOSITIONS AND OPERATORS ON HARDY SPACES STEFANO MEDA, PETER SJ¨OGREN AND MARIA space, we consider operators defined and uniformly bounded on atoms of a Hardy space Hp . The question between countable and finite atomic decompositions in Hardy spaces. 1. Introduction and definitions We

Meda, Stefano

312

The Geography of Organic Decomposition Rates  

Microsoft Academic Search

Decomposition of organic matter is a critical link in the cycling of nutrients through vegetated ecosystems. The primary controls of decay rates are climatic energy and moisture and the chemical-physical nature of the organic matter. A model was developed which uses these controls to predict the geography of decomposition rates for Canada and the United States. Annual actual evapotranspiration (AE)

Vernon Meentemeyer

1984-01-01

313

English and Turkish Pupils' Understanding of Decomposition  

ERIC Educational Resources Information Center

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…

Cetin, Gulcan

2007-01-01

314

Fischer Decomposition for Difference Dirac Operators  

Microsoft Academic Search

.  We establish the basis of a discrete function theory starting with a Fischer decomposition for difference Dirac operators.\\u000a Discrete versions of homogeneous polynomials, Euler and Gamma operators are obtained. As a consequence we obtain a Fischer\\u000a decomposition for the discrete Laplacian.

Nelson Faustino; U. Kähler

2007-01-01

315

ON AN OPTIMAL DECOMPOSITION IN ZYGMUND SPACES  

Microsoft Academic Search

An optimal decomposition formula for the norm in the Orlicz space L(logL)fi is given. New proofs of some results involving L(logL)fi spaces are given and the decomposition is applied to apriori estimates for elliptic partial dierential equations with the right-hand side in Zygmund classes.

ALBERTO FIORENZA; MIROSLAV KRBEC

2002-01-01

316

Management intensity alters decomposition via biological pathways  

E-print Network

in replicated con- ventional-till, no-till, and old field agricultural sites for both corn and grass litter communities. However, decomposition rates in no-till were not significantly different from those in old field or conventional-till sites. After decomposition, grass residue in both conventional- and no-till systems

Cleveland, Cory

317

Distributed Estimation via Dual Decomposition Sikandar Samar  

E-print Network

Distributed Estimation via Dual Decomposition Sikandar Samar Integrated Data Systems Department into a globally optimal estimate that satisfies the coupling constraints. The approach uses dual decomposition likelihood estimate, subject to the consistency constraints. There is a large relevant body of prior

318

Efficient HRTF Computation using Adaptive Rectangular Decomposition  

E-print Network

Efficient HRTF Computation using Adaptive Rectangular Decomposition Alok Meshram1, Ravish Mehra1 decomposition with the acoustic reciprocity principle and the Kirchhoff surface integral representation modification of the signal due to the scattering of sound waves around the head (especially outer ears), body

North Carolina at Chapel Hill, University of

319

BRAIDS AND OPEN BOOK DECOMPOSITIONS Elena Pavelescu  

E-print Network

BRAIDS AND OPEN BOOK DECOMPOSITIONS Elena Pavelescu A Dissertation in Mathematics Presented the great postcards. I am most grateful to my parents, Elena and Mircea Bogdan, and to the rest of my family DECOMPOSITIONS Elena Pavelescu John Etnyre, Advisor In this thesis we generalize Alexander's and Bennequin's work

Plotkin, Joshua B.

320

Review of human decomposition processes in soil  

Microsoft Academic Search

In-soil human decomposition is comprehensively described in terms of the physico-chemical and bacterial environmental conditions. Much of the understanding comes from considerations of cemetery studies and experimentation with adipocere. The understandings are relevant for further studies in cemetery management, exhumations, forensic investigations and anthropology. In the soil, cadavers are subject to various sets of decomposition processes principally resulting from aerobic

B. B. Dent; S. L. Forbes; B. H. Stuart

2004-01-01

321

Decomposition of rice residue in tropical soils  

Microsoft Academic Search

The decomposition processes of intact rice residue (leaf blades) in Maahas soil of the Philippines were investigated by incubation experiments at 30°C. The experiments dealt with nitrogen immobilization by rice residue under lowland and upland conditions. Rice residue which is low in nitrogen. absorbed nitrogen from the soil and from the added fertilizer (ammonium sulfate) during its decomposition under both

Tadakatsu Yoneyama; Tomio Yoshida

1977-01-01

322

Template matching based on quadtree Zernike decomposition  

Microsoft Academic Search

In this paper a novel technique for rotation independent template matching via Quadtree Zernike decomposition is presented. Both the template and the target image are decomposed by using a complex polynomial basis. The template is analyzed in block-based manner by using a quad tree decomposition. This allows the system to better identify the object features. Searching for a complex pattern

Alessandro Neri; Marco Carli; Veronica Palma; Luca Costantini

2009-01-01

323

Chinese Orthographic Decomposition and Logographic Structure  

ERIC Educational Resources Information Center

"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…

Cheng, Chao-Ming; Lin, Shan-Yuan

2013-01-01

324

Tree decompositions and social graphs  

E-print Network

Recent work has established that large informatics graphs such as social and information networks have non-trivial tree-like structure when viewed at moderate size scales. Here, we present results from the first detailed empirical evaluation of the use of tree decomposition (TD) heuristics for structure identification and extraction in social graphs. Although TDs have historically been used in structural graph theory and scientific computing, we show that---even with existing TD heuristics developed for those very different areas---TD methods can identify interesting structure in a wide range of realistic informatics graphs. Among other things, we show that TD methods can identify structures that correlate strongly with the core-periphery structure of realistic networks, even when using simple greedy heuristics; we show that the peripheral bags of these TDs correlate well with low-conductance communities (when they exist) found using local spectral computations; and we show that several types of large-scale "...

Adcock, Aaron B; Mahoney, Michael W

2014-01-01

325

Thermal Decomposition of a Melt-Castable High Explosive: Isoconversional Analysis of Gregory T. Long and Charles A. Wight*  

E-print Network

near the end of the reaction. The rates clearly exhibit acceleratory behavior that is ascribed confined in sealed high-pressure crucibles, exothermic thermal decomposition is observed. The activation energy for thermal decomposition has been determined as a function of the extent of reaction

Utah, University of

326

Litter Decomposition in Three Plantation Species in Semi-Arid and SubHumid Regions of Central India  

Microsoft Academic Search

The forest floor litter decomposition rate followed in the order: Tectona grandis(teak) > Madhuka indica (mahua) > Butea monosperma (palas). Higher decomposition rates were observed during rainy season and lowest during winter. The decay rate was significantly correlated with rainfall and soil moisture, and with population densities of earthworms. The lumbricid distribution under three plantations of semi-arid and sub-humid regions

M. C. Manna; S. Jha; P. K. Ghosh; T. K. Ganguly; K. N. Singh

2004-01-01

327

J. Geomag. Geoelectr., 49, 767-789, 1997 Electric and Magnetic Field Galvanic Distortion Decomposition of BC87 Data  

E-print Network

Decomposition of BC87 Data Alan D. CHAVE1 and Alan G. JONES 2 1 Woods Hole Oceanographic Institution, Woods Hole field galvanic distortion model, and hence can be removed using a tensor decomposition approach uniform across the distorting body and comparable to that at the observation point. 1. Introduction

Jones, Alan G.

328

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

PubMed Central

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

Zhang, Weidong; Wang, Xiaofeng; Wang, Silong

2013-01-01

329

DEVELOPMENT OF A NOVEL CATALYST FOR NO DECOMPOSITION  

SciTech Connect

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 NOx 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 proposed research 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}, CO{sub 2}, and elevated temperatures. Therefore, it is proposed to perform 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. It is also proposed to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. In the previous reporting period some TPRx runs with the catalysts containing 15% and 10% Pt were repeated due to the uncertainty of the oxygen content of the feed. In this reporting period runs were made with feed gas mixtures containing water vapor. Two reaction regimes, one below and the other above 750 K were observed. Presence of water vapor slightly enhanced the catalyst activity, but decreased the selectivity towards N{sub 2} at low temperatures.

Ates Akyurtlu; Jale F. Akyurtlu

2005-09-29

330

Generalized covariation and extended Fukushima decompositions for Banach valued processes.  

E-print Network

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

Paris-Sud XI, Université de

331

Management intensity alters decomposition via biological pathways  

USGS Publications Warehouse

Current conceptual models predict that changes in plant litter chemistry during decomposition are primarily regulated by both initial litter chemistry and the stage-or extent-of mass loss. Far less is known about how variations in decomposer community structure (e.g., resulting from different ecosystem management types) could influence litter chemistry during decomposition. Given the recent agricultural intensification occurring globally and the importance of litter chemistry in regulating soil organic matter storage, our objectives were to determine the potential effects of agricultural management on plant litter chemistry and decomposition rates, and to investigate possible links between ecosystem management, litter chemistry and decomposition, and decomposer community composition and activity. We measured decomposition rates, changes in litter chemistry, extracellular enzyme activity, microarthropod communities, and bacterial versus fungal relative abundance in replicated conventional-till, no-till, and old field agricultural sites for both corn and grass litter. After one growing season, litter decomposition under conventional-till was 20% greater than in old field communities. However, decomposition rates in no-till were not significantly different from those in old field or conventional-till sites. After decomposition, grass residue in both conventional- and no-till systems was enriched in total polysaccharides relative to initial litter, while grass litter decomposed in old fields was enriched in nitrogen-bearing compounds and lipids. These differences corresponded with differences in decomposer communities, which also exhibited strong responses to both litter and management type. Overall, our results indicate that agricultural intensification can increase litter decomposition rates, alter decomposer communities, and influence litter chemistry in ways that could have important and long-term effects on soil organic matter dynamics. We suggest that future efforts to more accurately predict soil carbon dynamics under different management regimes may need to explicitly consider how changes in litter chemistry during decomposition are influenced by the specific metabolic capabilities of the extant decomposer communities.

Wickings, Kyle; Grandy, A. Stuart; Reed, Sasha; Cleveland, Cory

2011-01-01

332

Hydrogen peroxide decomposition on manganese oxide (pyrolusite): Kinetics, intermediates, and mechanism  

Microsoft Academic Search

The objective of this study is the kinetic interpretation of hydrogen peroxide decomposition on manganese oxide (pyrolusite) and the explanation of the reaction mechanism including the hydroperoxide\\/superoxide anion. The decomposition of hydrogen peroxide on manganese oxide at pH 7 was represented by a pseudo first-order model. The maximum value of the observed first-order rates constants (kobs) was 0.741min?1 at 11.8

Si-Hyun Do; Bill Batchelor; Hong-Kyun Lee; Sung-Ho Kong

2009-01-01

333

Structure, Growth, and Decomposition of Laminated Algal-Bacterial Mats in Alkaline Hot Springs  

PubMed Central

Laminated mats of unique character in siliceous alkaline hot springs of Yellowstone Park are formed predominantly by two organisms, a unicellular blue-green alga, Synechococcus lividus, and a filamentous, gliding, photosynthetic bacterium, Chloroflexus aurantiacus. The mats can be divided approximately into two major zones: an upper, aerobic zone in which sufficient light penetrates for net photosynthesis, and a lower, anaerobic zone, where photosynthesis does not occur and decomposition is the dominant process. Growth of the mat was followed by marking the mat surface with silicon carbide particles. The motile Chloroflexus migrates vertically at night, due to positive aerotaxis, responding to reduced O2 levels induced by dark respiration. The growth rates of mats were estimated at about 50 ?m/day. Observations of a single mat at Octopus Spring showed that despite the rapid growth rate, the thickness of the mat remained essentially constant, and silicon carbide layers placed on the surface gradually moved to the bottom of the mat, showing that decomposition was taking place. There was a rapid initial rate of decomposition, with an apparent half-time of about 1 month, followed by a slower period of decomposition with a half-time of about 12 months. Within a year, complete decomposition of a mat of about 2-cm thickness can occur. Also, the region in which decomposition occurs is strictly anaerobic, showing that complete decomposition of organic matter from these organisms can occur in the absence of O2. Images PMID:16345254

Doemel, W. N.; Brock, Thomas D.

1977-01-01

334

DEVELOPMENT OF A NOVEL CATALYST FOR NO DECOMPOSITION  

SciTech Connect

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 proposed research 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}, CO{sub 2}, and elevated temperatures. Therefore, it is proposed to perform 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. It is also proposed to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. In the current reporting period first the GC-MS system was calibrated. Then the TPD runs for the 15% Pt/SnO{sub 2} catalyst after treatment with NO and subsequent treatments with NO and O{sub 2} were done. For these runs the catalyst was pretreated with dry helium for 2 hours at 40 C.

Ates Akyurtlu; Jale F. Akyurtlu

2004-05-01

335

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

PubMed

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

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

2013-03-01

336

Effects of depleted uranium on decomposition and soil bacterial communities  

SciTech Connect

A soil microcosm experiment was used to analyze effects of depleted uranium on soil community function. Uranium treatment levels were 0, 50, 500, 5,000, 10,000, and 25,000 ppm. Decomposition was followed through measurement of mass loss of several different plant litter types, as well as through analysis of soil respiration. Litter types tested were lignin, cellulose, and both high-nitrogen and low-nitrogen grass. Functional diversity of soil bacteria was assessed using the BIOLOG system of sole carbon source utilization. There was a significant reduction in litter decomposition at the 25,000 ppm level versus the control for all litter types except the high-nitrogen grass. Changes in functional diversity of the soil bacterial communities were more pronounced. Changes were observed both in terms of the number of carbon sources utilized, as well as in the intensity of utilization.

Meyer, M.; Paschke, M.W.; McLendon, T. [Colorado State Univ., Fort Collins, CO (United States). Center for Ecological Risk Assessment and Management

1995-12-31

337

Condensed-phase thermal decomposition of TATB investigated by atomic force microscopy (AFM) and simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS)  

SciTech Connect

A combination of techniques has been used to investigate the condensed-phase thermal decomposition of TATB. STMBMS has been used to identify the thermal decomposition products and their temporal correlation`s. These experiments have shown that the condensed-phase decomposition proceeds through several autocatalytic pathways. Both low and high molecular weight decomposition products have been identified. Mono-, di- and tri-furazans products have been identified and, their temporal behaviors are consistent with a stepwise loss of water. AFM has been used to correlate the decomposition chemistry with morphological changes occurring as a function of heating. Patches of small 25-140 nm round holes were observed throughout the lattice of TATB crystals that were heated briefly to 300C. It is likely that these holes show where decomposition reactions have started. Evidence of decomposition products have been seen in TATB that has been held at 250C for one hour.

Land, T.A.; Siekhaus, W.J.; Foltz, M.F. [Lawrence Livermore National Lab., CA (United States); Behrens, R. Jr. [Sandia National Labs., Livermore, CA (United States)

1993-05-01

338

Nonnegative Decomposition of Multivariate Information  

E-print Network

Of the various attempts to generalize information theory to multiple variables, the most widely utilized, interaction information, suffers from the problem that it is sometimes negative. Here we reconsider from first principles the general structure of the information that a set of sources provides about a given variable. We begin with a new definition of redundancy as the minimum information that any source provides about each possible outcome of the variable, averaged over all possible outcomes. We then show how this measure of redundancy induces a lattice over sets of sources that clarifies the general structure of multivariate information. Finally, we use this redundancy lattice to propose a definition of partial information atoms that exhaustively decompose the Shannon information in a multivariate system in terms of the redundancy between synergies of subsets of the sources. Unlike interaction information, the atoms of our partial information decomposition are never negative and always support a clear interpretation as informational quantities. Our analysis also demonstrates how the negativity of interaction information can be explained by its confounding of redundancy and synergy.

Paul L. Williams; Randall D. Beer

2010-04-14

339

Unimolecular thermal decomposition of dimethoxybenzenes  

NASA Astrophysics Data System (ADS)

The unimolecular thermal decomposition mechanisms of o-, m-, and p-dimethoxybenzene (CH3O-C6H4-OCH3) have been studied using a high temperature, microtubular (?tubular) SiC reactor with a residence time of 100 ?s. Product detection was carried out using single photon ionization (SPI, 10.487 eV) and resonance enhanced multiphoton ionization (REMPI) time-of-flight mass spectrometry and matrix infrared absorption spectroscopy from 400 K to 1600 K. The initial pyrolytic step for each isomer is methoxy bond homolysis to eliminate methyl radical. Subsequent thermolysis is unique for each isomer. In the case of o-CH3O-C6H4-OCH3, intramolecular H-transfer dominates leading to the formation of o-hydroxybenzaldehyde (o-HO-C6H4-CHO) and phenol (C6H5OH). Para-CH3O-C6H4-OCH3 immediately breaks the second methoxy bond to form p-benzoquinone, which decomposes further to cyclopentadienone (C5H4=O). Finally, the m-CH3O-C6H4-OCH3 isomer will predominantly follow a ring-reduction/CO-elimination mechanism to form C5H4=O. Electronic structure calculations and transition state theory are used to confirm mechanisms and comment on kinetics. Implications for lignin pyrolysis are discussed.

Robichaud, David J.; Scheer, Adam M.; Mukarakate, Calvin; Ormond, Thomas K.; Buckingham, Grant T.; Ellison, G. Barney; Nimlos, Mark R.

2014-06-01

340

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)

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.

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

1990-01-01

341

Musculoskeletal responses of 2-year-old Thoroughbred horses to early training. 1. Study design, and clinical, nutritional, radiological and histological observations  

Microsoft Academic Search

AIMS: This is the first in a series of papers reporting studies in 2-year-old Thoroughbred racehorses that aimed to determine the response of musculoskeletal tissues to early training on grass and sand racetracks. In this paper, the experimental set-up of the whole study is described, and nutritional, workload, and clinical, radiographic and pathological outcomes are reported, including semi-quantitative assessment of

EC Firth; CW Rogers; NR Perkins; BH Anderson; ND Grace

2004-01-01

342

Radiation-Induced Decomposition of PETN and TATB under Extreme Conditions  

SciTech Connect

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.

Giefers, Hubertus; Pravica, Michael (UNLV)

2008-11-03

343

NMR analysis of diacyl peroxide decomposition in methanol in response to temperature and microwave radiation  

NASA Astrophysics Data System (ADS)

We have studied the decomposition of benzoyl and acetyl benzoyl peroxides in methanol-d4 in response to temperature and microwave radiation. We have shown that chemically-induced dynamic nuclear polarization (CIDNP) can be observed even when the reactions are carried out in spectrometers with high magnetic fields. In this case, spin correlation persists in geminal radical pairs involving labile acyloxyl radicals. Regardless of the method used to initiate peroxide decomposition, the same amount of products are formed. Homolysis occurs according to a chain mechanism. The contribution of induced decomposition decreases over the course of the reaction. Dissolved oxygen molecules efficiently terminate the chain, decreasing the rate of peroxide decomposition. In the case of acetyl benzoyl peroxide, the product yield depends on the initiation mechanism: for microwave irradiation, the solvent molecules are more active while dissolved oxygen is less active than in thermolysis.

Haidukevich, O. A.; Skakovskii, E. D.; Tychinskaya, L. Yu.; Zvereva, T. D.; Dikusar, E. A.; Lamotkin, S. A.; Rykov, S. V.

2012-05-01

344

Ceramic decomposition under irradiation, 1987. Progress report  

SciTech Connect

Our quantitative determinations of the decomposition of thin film and bulk ceramic materials during electron microscopy has shown that the radiation damage effect is a complex one depending dielectric and thermochemical properties. In low melting temperature glasses, for example, much of the activity is due to field enhanced diffusion of low atomic weight species. This is particularly true of bulk specimens and for the case of binary soda-borosilicate glass the sodium depletion in the SEM can be quantitatively described in terms of this effect. Studies with thin specimens of refractory carbides show that in these materials the carbon depletion is due to direct displacement processes and that here the electric fields give rise to recombination effects. The studies of ceramic thin films suitable for reference standards is continuing as a joint effort with the Rockwell Science Center. Work is in progress to describe the in plane crystallization that is observed in terms of the latent heat involved and the configurational entropy of the propagating interface.

Howitt, D.G.

1987-12-31

345

Experimental Shock Decomposition of Siderite to Magnetite  

NASA Technical Reports Server (NTRS)

The debate about fossil life on Mars includes the origin of magnetites of specific sizes and habits in the siderite-rich portions of the carbonate spheres in ALH 84001 [1,2]. Specifically [2] were able to demonstrate that inorganic synthesis of these compositionally zoned spheres from aqueous solutions of variable ion-concentrations is possible. They further demonstrated the formation of magnetite from siderite upon heating at 550 C under a Mars-like CO2-rich atmosphere according to 3FeCO3 = Fe3O4 + 2CO2 + CO [3] and they postulated that the carbonates in ALH 84001 were heated to these temperatures by some shock event. The average shock pressure for ALH 84001, substantially based on the refractive index of diaplectic feldspar glasses [3,4,5] is some 35-40 GPa and associated temperatures are some 300-400 C [4]. However, some of the feldspar is melted [5], requiring local deviations from this average as high as 45-50 GPa. Indeed, [5] observes the carbonates in ALH 84001 to be melted locally, requiring pressures in excess of 60 GPa and temperatures > 600 C. Combining these shock studies with the above inorganic synthesis of zoned carbonates it seems possible to produce the ALH 84001 magnetites by the shock-induced decomposition of siderite.

Bell, M. S.; Golden, D. C.; Zolensky, M. E.

2005-01-01

346

Spherical harmonic decomposition of solar magnetic fields  

NASA Astrophysics Data System (ADS)

We have investigated the temporal evolution of large-scale magnetic fields in the solar photosphere during the time interval 1966-2004 by means of spherical harmonic decomposition and subsequent time series analysis. Two data sets of daily magnetograms recorded at the Mt. Wilson and Kitt Peak observatories were used to calculate the spherical harmonic coefficients of the radial magnetic field for axisymmetric (m=0) and non-axisymmetric (m? 0) modes. Time series analysis was then applied to deduce their temporal variations. A third data set of synoptic Carrington rotation maps from Kitt Peak was also analyzed for completeness. Besides the obvious 22 yr magnetic cycle, we have found evidence for intermittent oscillations with periods of 2.1{-}2.5 yr, 1.5{-}1.8 yr and 1.2{-}1.4 yr. The biennial oscillation occurred during the solar maxima of cycles 20-22 (and likely also during the current cycle 23) and was most pronounced for modes that resemble non-linear dynamo waves (Stix 1972, A&A, 20, 9). The 1.5{-}1.8 yr period was stronger during the odd cycles 21 and 23 than during the even cycles 20 and 22, whereas the opposite was the case for the 1.2{-}1.4 yr period. Similar variations of 1.5{-}1.8 yr have recently been detected in the north-south asymmetry of the magnetic flux (Knaack et al. 2004, A&A, 418, L17), while quasi-periodicities of 1.3 yr have been observed in the rotation rate near the base of the convection zone (Howe et al. 2000, Science, 287, 2456), in the heliosphere and geomagnetic activity (Lockwood 2001, J. Geophys. Res., 106, 16 021) in sunspot areas (Krivova & Solanki 2002, A&A, 394, 701), and in the large-scale photospheric magnetic field (Knaack et al. 2005, A&A, in press). In agreement with the latter study, we have found additional quasi-periodicities in the range 320{-}100 d and rotational periods of 29.0±0.1d, 28.2±0.1d, and 26.8±0.1d. Compared to earlier decompositions by Stenflo & Vogel (1986, Nature, 319, 285) and Stenflo & Güdel (1988, A&A, 191, 137), we can confirm the main features of their results, although several modifications need to be considered.

Knaack, R.; Stenflo, J. O.

2005-07-01

347

Phase Field Method: Spinodal Decomposition Computer Laboratory  

NSDL National Science Digital Library

In this lab, spinodal decomposition is numerically implemented in FiPy. A simple example python script (spinodal.py) summarizes the concepts. This lab is intended to complement the "Phase Field Method: An Introduction" lecture

Garcã­a, R. E.

2008-08-25

348

RECIPROCITY LAWS AND PRIME DECOMPOSITION HARUZO HIDA  

E-print Network

RECIPROCITY LAWS AND PRIME DECOMPOSITION HARUZO HIDA I would like to describe reciprocity laws appeared in the history of number t* *heory in terms.Quadratic Reciprocity Law i j For an integer n (p - n

Hida, Haruzo

349

A Lagrangean Decomposition Approach for Robust Combinatorial ...  

E-print Network

ble sources of uncertainty are measurement errors or problem parameters that ... Ministry of Economics and Technology within the 6th Energy Research ..... As an alternative to the Lagrangean decomposition approach, the nonlinear model (3) ...

2014-07-24

350

9 CFR 354.131 - Decomposition.  

Code of Federal Regulations, 2011 CFR

...MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of...

2011-01-01

351

9 CFR 354.131 - Decomposition.  

Code of Federal Regulations, 2012 CFR

...MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of...

2012-01-01

352

9 CFR 354.131 - Decomposition.  

Code of Federal Regulations, 2013 CFR

...MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of...

2013-01-01

353

Interactive simulation of fire, burn and decomposition  

E-print Network

combustible products from nearby matter through chemical decomposition. This process is called pyrolysis [8]. Thus, when an object (such as a piece of wood) burns, the flames are formed from combustible portions of the object being vaporized and then oxidizing... combustible products from nearby matter through chemical decomposition. This process is called pyrolysis [8]. Thus, when an object (such as a piece of wood) burns, the flames are formed from combustible portions of the object being vaporized and then oxidizing...

Melek, Zeki

2008-10-10

354

Moisture drives surface decomposition in thawing tundra  

NASA Astrophysics Data System (ADS)

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.

Hicks Pries, Caitlin E.; Schuur, E. A. G.; Vogel, Jason G.; Natali, Susan M.

2013-07-01

355

Domain decomposition for the SPN solver MINOS  

SciTech Connect

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)

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

356

Critical analysis of nitramine decomposition data: Activation energies and frequency factors for HMX and RDX decomposition  

NASA Technical Reports Server (NTRS)

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.

Schroeder, M. A.

1980-01-01

357

[Putrefaction in a mortuary cold room? Unusual progression of postmortem decomposition processes].  

PubMed

This article illustrates the rare case of rapid body decomposition in an uncommonly short postmortem interval. A clear discrepancy between early postmortem changes at the crime scene and advanced body decomposition at the time of autopsy were seen. Subsequent police investigation identified a failure in the cooling system of the morgue as probable cause. However, due to the postmortem status of the body, a moderate rise in temperature alone is not considered to have caused the full extent of postmortem changes. Therefore, other factors must have been present, which accelerated the postmortem decomposition processes. In our opinion, the most reasonable explanation for this phenomenon would be a rather long resting time of the corpse in a non-refrigerated hearse on a hot summer day. PMID:23678626

Kunz, Sebastian N; Brandtner, Herwig; Meyer, Harald

2013-01-01

358

Controlled rate thermal decomposition of synthetic bayerite under vacuum  

Microsoft Academic Search

Influences of the controlled decomposition rate and controlled residual pressure on the thermal decomposition process of synthetic bayerite were investigated by applying a method of controlled rate evolved gas detection (CREGD). Comparing with the conventional process under linearly increasing temperature, the thermal decomposition process of the synthetic bayerite at a controlled decomposition rate (?10?2 mg min?1) under controlled residual pressure

Nobuyoshi Koga; Shuto Yamada

2004-01-01

359

DECOMPOSITION-BASED ASSEMBLY SYNTHESIS OF STRUCTURAL PRODUCTS: PRELIMINARY RESULTS  

E-print Network

is technically or eco- nomically infeasible. Figure 1 shows an example of the decomposition of an automotive body. Example of decomposition of an automotive body front. Since a decomposition determines basic componentDECOMPOSITION-BASED ASSEMBLY SYNTHESIS OF STRUCTURAL PRODUCTS: PRELIMINARY RESULTS Kazuhiro Saitou

Saitou, Kazuhiro "Kazu"

360

Thermal decomposition of charring materials  

SciTech Connect

Experimental techniques and methods were developed to investigate the transient process of wood pyrolysis under different levels of external radiation, moisture content of the wood sample, and oxygen concentration of the ambient atmosphere. A unique small-scale combustion-wind tunnel was constructed to conduct the pyrolysis experiments and to obtain the time dependent gasification mass flux, surface and in-depth temperatures, and evolved products of pyrolysis (CO, CO{sub 2}, H{sub 2}O, and total hydrocarbons (THC)) for thermally thick samples of Douglas-fir. Experiments were performed both in inert atmosphere (nitrogen), and in air at several different heat fluxes and three different moisture contents of wood. Time dependent empirical chemical composition, char yield, and the heat of combustion of the pyrolysis products were determined. The experimental results indicate that the presence of moisture reduces the pyrolysis mass flux and delays the occurrence of its maxima. Presence of oxygen drastically increases the pyrolysis mass flux but its effect specially at lower temperatures depends on the experimental conditions such as the boundary layer thickness over the wood surface. Char yield, chemical composition of the volatiles, and the heat of combustion were found to vary during the pyrolysis process and with changes in the environmental conditions and wood moisture content. The pyrolysis temperature assumption often used for the simplified modeling of wood pyrolysis was examined in detail by considering two otherwise identical models; one with infinitely fast decomposition kinetics and the other with finite rate chemistry. It was concluded that the pyrolysis temperature is not a material property and different pyrolysis temperatures are needed for every problem.

Nurbakhsh, S.

1989-01-01

361

Roaming radical kinetics in the decomposition of acetaldehyde.  

PubMed

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. PMID:20038152

Harding, Lawrence B; Georgievskii, Yuri; Klippenstein, Stephen J

2010-01-21

362

Roaming radical kinetics in the decomposition of acetaldehyde.  

SciTech Connect

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.

Harding, L. B.; Georgievskii, Y.; Klippenstein, S. J.; Chemical Sciences and Engineering Division

2010-01-01

363

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

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

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

364

Comparison of the Decomposition VOC Profile during Winter and Summer in a Moist, Mid-Latitude (Cfb) Climate.  

PubMed

The investigation of volatile organic compounds (VOCs) associated with decomposition is an emerging field in forensic taphonomy due to their importance in locating human remains using biological detectors such as insects and canines. A consistent decomposition VOC profile has not yet been elucidated due to the intrinsic impact of the environment on the decomposition process in different climatic zones. The study of decomposition VOCs has typically occurred during the warmer months to enable chemical profiling of all decomposition stages. The present study investigated the decomposition VOC profile in air during both warmer and cooler months in a moist, mid-latitude (Cfb) climate as decomposition occurs year-round in this environment. Pig carcasses (Sus scrofa domesticus L.) were placed on a soil surface to decompose naturally and their VOC profile was monitored during the winter and summer months. Corresponding control sites were also monitored to determine the natural VOC profile of the surrounding soil and vegetation. VOC samples were collected onto sorbent tubes and analyzed using comprehensive two-dimensional gas chromatography - time-of-flight mass spectrometry (GC×GC-TOFMS). The summer months were characterized by higher temperatures and solar radiation, greater rainfall accumulation, and comparable humidity when compared to the winter months. The rate of decomposition was faster and the number and abundance of VOCs was proportionally higher in summer. However, a similar trend was observed in winter and summer demonstrating a rapid increase in VOC abundance during active decay with a second increase in abundance occurring later in the decomposition process. Sulfur-containing compounds, alcohols and ketones represented the most abundant classes of compounds in both seasons, although almost all 10 compound classes identified contributed to discriminating the stages of decomposition throughout both seasons. The advantages of GC×GC-TOFMS were demonstrated for detecting and identifying trace levels of VOCs, particularly ethers, which are rarely reported as decomposition VOCs. PMID:25412504

Forbes, Shari L; Perrault, Katelynn A; Stefanuto, Pierre-Hugues; Nizio, Katie D; Focant, Jean-François

2014-01-01

365

Comparison of the Decomposition VOC Profile during Winter and Summer in a Moist, Mid-Latitude (Cfb) Climate  

PubMed Central

The investigation of volatile organic compounds (VOCs) associated with decomposition is an emerging field in forensic taphonomy due to their importance in locating human remains using biological detectors such as insects and canines. A consistent decomposition VOC profile has not yet been elucidated due to the intrinsic impact of the environment on the decomposition process in different climatic zones. The study of decomposition VOCs has typically occurred during the warmer months to enable chemical profiling of all decomposition stages. The present study investigated the decomposition VOC profile in air during both warmer and cooler months in a moist, mid-latitude (Cfb) climate as decomposition occurs year-round in this environment. Pig carcasses (Sus scrofa domesticus L.) were placed on a soil surface to decompose naturally and their VOC profile was monitored during the winter and summer months. Corresponding control sites were also monitored to determine the natural VOC profile of the surrounding soil and vegetation. VOC samples were collected onto sorbent tubes and analyzed using comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (GC×GC-TOFMS). The summer months were characterized by higher temperatures and solar radiation, greater rainfall accumulation, and comparable humidity when compared to the winter months. The rate of decomposition was faster and the number and abundance of VOCs was proportionally higher in summer. However, a similar trend was observed in winter and summer demonstrating a rapid increase in VOC abundance during active decay with a second increase in abundance occurring later in the decomposition process. Sulfur-containing compounds, alcohols and ketones represented the most abundant classes of compounds in both seasons, although almost all 10 compound classes identified contributed to discriminating the stages of decomposition throughout both seasons. The advantages of GC×GC-TOFMS were demonstrated for detecting and identifying trace levels of VOCs, particularly ethers, which are rarely reported as decomposition VOCs. PMID:25412504

Forbes, Shari L.; Perrault, Katelynn A.; Stefanuto, Pierre-Hugues; Nizio, Katie D.; Focant, Jean-François

2014-01-01

366

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

367

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

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

Percival, Don

368

DARBY et al.: BACKING OFF: HIERARCHICAL DECOMPOSITION OF ACTIVITY 1 Backing Off: Hierarchical Decomposition of  

E-print Network

DARBY et al.: BACKING OFF: HIERARCHICAL DECOMPOSITION OF ACTIVITY 1 Backing Off: Hierarchical Decomposition of Activity for 3D Novel Pose Recovery John Darby1 j.darby@mmu.ac.uk Baihua Li1 b pose estimation, even simple models of the human body lead to high-dimensional state spaces. Where

Costen, Nickolas

369

Repeated decompositions reveal the stability of infomax decomposition of fMRI data  

Microsoft Academic Search

In this study, we decomposed 12 fMRI data sets from six subjects each 101 times using the infomax algorithm. The first decomposition was taken as a reference decomposition; the others were used to form a component matrix of 100 by 100 components. Equivalence relations between components in this matrix, defined as maximum spatial correlations to the components of the reference

Jeng-Ren Duann; Tzyy-Ping Jung; Terrence J. Sejnowski; Scott Makeig

2005-01-01

370

Long-term decomposition of grass roots as affected by elevated atmospheric carbon dioxide  

SciTech Connect

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.

Ginkel, J.H. van; Gorissen, A. [Institute for Agrobiology and Soil Fertility, Wageningen (Netherlands); Veen, J.A. van [Leiden Univ. (Netherlands)

1996-09-01

371

Decomposition of methanol on oxygen-modified Fe(100) surfaces. II. Preadsorbed oxygen as poison, selectivity modifier and promoter  

NASA Astrophysics Data System (ADS)

Decomposition of methanol (CH 3OH) on the Fe(100) surface modified by low temperature adsorption of oxygen has been studied, using high resolution electron energy loss spectroscopy (HREELS) and temperature programmed reaction spectroscopy (TPRS). Fe(100) surfaces studied were modified by adsorption of O 2 at 113 K, and methanol decomposition as a function of oxygen coverage was monitored. The effect of pre-heating the oxygen overlayers on the methanol decomposition was also examined. Decomposition of methanol on these O-modified surfaces passes through a methoxy (-OCH 3) intermediate. The thermal stability of methoxy increases in the presence of pre-adsorbed oxygen. At low coverage, atomic oxygen occupies four-fold hollow sites. In this case, the effect of oxygen on the methanol decomposition is similar to that observed previously on the annealed O-modified surfaces. At higher oxygen coverage, a more weakly bound non-hollow site oxygen also exists on the surface, which reacts with hydroxyl (-OH) hydrogen of the CH 3OH, promoting the formation of methoxy. At high oxygen coverage (close to saturation coverage at 113 K), decomposition of methanol results in the formation of formaldehyde (H 2CO), without production of carbon monoxide (CO). This is very different from the decomposition of methanol on the clean Fe(100) surface, where decomposition leads to the formation of CO without H 2CO. The effect of oxygen modification is discussed in terms of changing relative probabilities of competing reaction pathways.

Lu, Jiong-Ping; Albert, Mark; Bernasek, Steven L.; Dwyer, Daniel J.

1990-12-01

372

A comparative study of the effects of decomposition rate control and mechanical grinding on the thermal decomposition of aluminum hydroxide  

Microsoft Academic Search

Summary Two different processes of the thermal decomposition of synthetic bayerite, i.e., the non-isothermal decomposition of mechanically ground sample in flowing N2 and the controlled rate thermal decomposition of crystalline bayerite under vacuum, were investigated comparatively. In comparison with the conventional non-isothermal decomposition of crystalline bayerite in flowing N2, the reaction temperature of the thermal decomposition was lowered by the

N. Koga

2005-01-01

373

Steganography based on pixel intensity value decomposition  

NASA Astrophysics Data System (ADS)

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.

Abdulla, Alan Anwar; Sellahewa, Harin; Jassim, Sabah A.

2014-05-01

374

Regarding the Potential Impact of Double Star Observations on Conceptions of the Universe of Stars in the Early 17TH Century  

E-print Network

Galileo Galilei believed that stars were distant suns whose sizes measured via his telescope were a direct indication of distance -- fainter stars (appearing smaller in the telescope) being farther away than brighter ones. Galileo argued in his Dialogue that telescopic observation of a chance alignment of a faint (distant) and bright (closer) star would reveal annual parallax, if such double stars were found. This would provide support both for Galileo's ideas concerning the nature of stars and for the motion of the Earth. However, Galileo actually made observations of such double stars, well before publication of the Dialogue. We show that the results of these observations, and the likely results of observations of any double star that was a viable subject for Galileo's telescope, would undermine Galileo's ideas, not support them. We argue that such observations would lead either to the more correct idea that stars were sun-like bodies of varying sizes which could be physically grouped, or to the less correc...

Graney, Christopher M

2008-01-01

375

Oxidative decomposition of formaldehyde catalyzed by a bituminous coal  

SciTech Connect

It has been observed that molecular hydrogen is formed during long-term storage of bituminous coals via oxidative decomposition of formaldehyde by coal surface peroxides. This study has investigated the effects of coal quantity, temperature, and water content on the molecular hydrogen formation with a typical American coal (Pittsburgh No. 6). The results indicate that the coal's surface serves as a catalyst in the formation processes of molecular hydrogen. Furthermore, the results also indicate that low temperature emission of molecular hydrogen may possibly be the cause of unexplained explosions in confined spaces containing bituminous coals, for example, underground mines or ship holds. 20 refs., 4 figs., 6 tabs.

Haim Cohen; Uri Green [Ariel University Center in Samaria, Beer Sheva (Israel). Biological Chemistry Department

2009-05-15

376

Development Of A Novel Catalyst For No Decomposition  

SciTech Connect

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 N2 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/SnO2 catalyst in the PI's laboratory. The main objective of the research that is being undertaken is the evaluation of the Pt/SnO2 catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O{sub 2}, CO{sub 2}, and elevated temperatures. Temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO2 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. In the previous reporting periods, runs were made with catalysts containing 15% Pt and 10% Pt on SnO{sub 2} were done. Catalysts containing 10% Pt resulted in significantly lower activities than 15% PT catalysts. Therefore, in the following tests 15% Pt/SnO{sub 2} catalysts were used. In the current reporting period runs to elucidate the effects of temperature, oxygen, water vapor, pretreatment temperature, and space velocity on NO dissociation were completed. 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.

Ates Akyurtlu; Jale F. Akyurtlu

2006-09-14

377

Development of a Novel Catalyst for No Decomposition  

SciTech Connect

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 NOx 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 N2 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/SnO2 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/SnO2 catalyst in the PI's laboratory. The main objective of the research that is being undertaken is the evaluation of the Pt/SnO2 catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O2, CO{sub 2}, and elevated temperatures. Temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO2 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. In the previous reporting periods, runs were made with catalysts containing 15% Pt and 10% Pt on SnO2 were done. Catalysts containing 10% Pt resulted in significantly lower actgivities than 15% PT catalysts. Therefore, in the following tests 15% Pt/SnO2 catalysts were used. Runs to elucidate the effects of temperature, oxygen, water vapor, pretreatment temperature, and space velocity on NO dissociation were completed. 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. In this reporting period, since no release time was available, no laboratory work was undertaken. Focus was on obtaining equilibrium data on various feed mixtures at temperatures up to 1000 K.

Ates Akyurtlu; Jale F. Akyurtlu

2007-03-14

378

Development of a Novel Catalyst for No Decomposition  

SciTech Connect

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.

Ates Akyurtlu; Jale Akyurtlu

2007-06-22

379

Overview of Decompositional, Modelbased Learning  

E-print Network

for unprecedented performance, such as smart buildings, reconfigurable factories, adaptive traffic systems of a smart building, demonstrating a significant improvement in learning rate. 1 Introduction Through artful factories and earth observing satellite networks. To achieve high performance these massive systems

Williams, Brian C.

380

Summer and early-fall sea-ice concentration in the Ross Sea: comparison of in situ ASPeCt observations and satellite passive  

E-print Network

image processing on a subset of nine helicopter flights to obtain ice concentration on a continuousCt observations and satellite passive microwave estimates Margaret A. KNUTH,1 Stephen F. ACKLEY2 1 Department in situ datasets were then compared with ice concentrations from SSM/I passive microwave satellite data

Texas at San Antonio, University of

381

Pacing Early Mars fluvial activity at Aeolis Dorsa: Implications for Mars 1 Science Laboratory observations at Gale Crater and Aeolis Mons 2  

E-print Network

for Mars 1 Science Laboratory observations at Gale Crater and Aeolis Mons 2 3's mound (Aeolis Mons) 13 took at least 10-100 Myr to accumulate, which is testable by the Mars Science Laboratory. 14 15 1. Introduction. 16

Kite, Edwin

382

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

NASA Astrophysics Data System (ADS)

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.

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.

2014-09-01

383

Multilevel domain decomposition for electronic structure calculations  

SciTech Connect

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.

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

384

Thermal decomposition hazard evaluation of hydroxylamine nitrate.  

PubMed

Hydroxylamine nitrate (HAN) is an important member of the hydroxylamine family and it is a liquid propellant when combined with alkylammonium nitrate fuel in an aqueous solution. Low concentrations of HAN are used primarily in the nuclear industry as a reductant in nuclear material processing and for decontamination of equipment. Also, HAN has been involved in several incidents because of its instability and autocatalytic decomposition behavior. This paper presents calorimetric measurement for the thermal decomposition of 24 mass% HAN/water. Gas phase enthalpy of formation of HAN is calculated using both semi-empirical methods with MOPAC and high-level quantum chemical methods of Gaussian 03. CHETAH is used to estimate the energy release potential of HAN. A Reactive System Screening Tool (RSST) and an Automatic Pressure Tracking Adiabatic Calorimeter (APTAC) are used to characterize thermal decomposition of HAN and to provide guidance about safe conditions for handling and storing of HAN. PMID:16154263

Wei, Chunyang; Rogers, William J; Mannan, M Sam

2006-03-17

385

Applications of the dynamic mode decomposition  

NASA Astrophysics Data System (ADS)

The decomposition of experimental data into dynamic modes using a data-based algorithm is applied to Schlieren snapshots of a helium jet and to time-resolved PIV-measurements of an unforced and harmonically forced jet. The algorithm relies on the reconstruction of a low-dimensional inter-snapshot map from the available flow field data. The spectral decomposition of this map results in an eigenvalue and eigenvector representation (referred to as dynamic modes) of the underlying fluid behavior contained in the processed flow fields. This dynamic mode decomposition allows the breakdown of a fluid process into dynamically revelant and coherent structures and thus aids in the characterization and quantification of physical mechanisms in fluid flow.

Schmid, P. J.; Li, L.; Juniper, M. P.; Pust, O.

2011-06-01

386

Isothermal Decomposition of Hydrogen Peroxide Dihydrate  

NASA Technical Reports Server (NTRS)

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.

Loeffler, M. J.; Baragiola, R. A.

2011-01-01

387

Decomposition of forest products buried in landfills.  

PubMed

The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C+H) loss of up to 38%, while loss for the other wood types was 0-10% in most samples. The C+H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27gOCg(-1) dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than previously reported. PMID:23942265

Wang, Xiaoming; Padgett, Jennifer M; Powell, John S; Barlaz, Morton A

2013-11-01

388

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

NASA Astrophysics Data System (ADS)

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.

Menéndez, Margarita

2009-05-01

389

Early orbit determination  

Microsoft Academic Search

Orbit determination for near real time monitoring of satellite movement based on limited observations is discussed. For geostationary satellites this early orbit determination requirement arises after injection into geostationary transfer orbit, apogee motor firing, and larger orbit maneuvers during the on-station phase. Early orbit determination is hampered by the limited amount of data caused by nonavailability of the tracking system.

S. Pallaschke

1986-01-01

390

Spectral decomposition aids AVO analysis in reservoir characterization: A case study of Blackfoot field, Alberta, Canada  

NASA Astrophysics Data System (ADS)

Blackfoot field, Alberta, Canada, has produced oil and gas from a Glauconitic compound incised valley-system. In this area channels can be filled with sands and/or shales. Differentiation of prospective channel sands and non-productive shales was always problematic due to the similarity in P-wave impedance of these two lithotypes. We study the spectral decomposition response to the hydrocarbons presence in the Glauconitic channel of Early Cretaceous age. From previous AVO analysis and modeling, a strong Class III AVO anomaly has been observed at the top of the porous sandstone in the upper valley, whereas shale had a very different AVO response. Furthermore, AVO inversion revealed additional information about lithology and fluid content in the channel. Our workflow starts from selecting a continuous horizon that was close and conforms to the channel interval; we then run spectral analyses for the channel area. Short Window Fourier Transform workflow could successfully image the channel's stratigraphic features and confirm results obtained from AVO analysis and inversion run on the data before being stacked. Additionally, the producing oil wells in the sand-fill channel were found to be correlating with high spectrum amplitude; while the dry wells in the shale-plugged channel fell in low amplitude anomaly.

Jung Yoon, Wang; Farfour, Mohammed

2012-09-01

391

Convergence Analysis of a Domain Decomposition Paradigm  

SciTech Connect

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.

Bank, R E; Vassilevski, P S

2006-06-12

392

High temperature decomposition of hydrogen peroxide  

NASA Technical Reports Server (NTRS)

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.

Parrish, Clyde F. (Inventor)

2011-01-01

393

Template matching based on quadtree Zernike decomposition  

NASA Astrophysics Data System (ADS)

In this paper a novel technique for rotation independent template matching via Quadtree Zernike decomposition is presented. Both the template and the target image are decomposed by using a complex polynomial basis. The template is analyzed in block-based manner by using a quad tree decomposition. This allows the system to better identify the object features. Searching for a complex pattern into a large multimedia database is based on a sequential procedure that verifies whether the candidate image contains each square of the ranked quadtree list and refining, step-by-step, the location and orientation estimate.

Neri, Alessandro; Carli, Marco; Palma, Veronica; Costantini, Luca

2009-02-01

394

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

Microsoft Academic Search

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

A Parsons; A Daley; R Begh; P Aveyard

2010-01-01

395

Integration of Observational and Analytical Methodologies to Characterize Organic Matter in Early Archaean Rocks: Distinguishing Biological from Abiotically Synthesized Carbonaceous Matter Structures  

Microsoft Academic Search

\\u000a Transmission Electron Microscopy (TEM) was applied to observe and characterize carbonaceous materials (CM) extracted from\\u000a black cherts and argillite in drill core from the Warrawoona Group of the Pilbara Craton, Western Australia. The black chert\\u000a came from a ‘white smoker type’ seafloor deposit in the ca. 3.49 Ga Dresser Formation, whereas the black argillites were obtained\\u000a from the 3.46 Ga

Miryam Glikson; Arthur H. Hickman; Lawrence J. Duck; Suzanne D. Golding; Robyn E. Webb

396

A single administration of methamphetamine to mice early in the light period decreases running wheel activity observed during the dark period.  

PubMed

Repeated intermittent administration of amphetamines acutely increases appetitive and consummatory aspects of motivated behaviors as well as general activity and exploratory behavior, including voluntary running wheel activity. Subsequently, if the drug is withdrawn, the frequency of these behaviors decreases, which is thought to be indicative of dysphoric symptoms associated with amphetamine withdrawal. Such decreases may be observed after chronic treatment or even after single drug administrations. In the present study, the effect of acute methamphetamine (METH) on running wheel activity, horizontal locomotion, appetitive behavior (food access), and consummatory behavior (food and water intake) was investigated in mice. A multi-configuration behavior apparatus designed to monitor the five behaviors was developed, where combined measures were recorded simultaneously. In the first experiment, naïve male ICR mice showed gradually increasing running wheel activity over three consecutive days after exposure to a running wheel, while mice without a running wheel showed gradually decreasing horizontal locomotion, consistent with running wheel activity being a positively motivated form of natural motor activity. In experiment 2, increased horizontal locomotion and food access, and decreased food intake, were observed for the initial 3h after acute METH challenge. Subsequently, during the dark phase period decreased running wheel activity and horizontal locomotion were observed. The reductions in running wheel activity and horizontal locomotion may be indicative of reduced dopaminergic function, although it remains to be seen if these changes may be more pronounced after more prolonged METH treatments. PMID:22079320

Kitanaka, Nobue; Kitanaka, Junichi; Hall, F Scott; Uhl, George R; Watabe, Kaname; Kubo, Hitoshi; Takahashi, Hitoshi; Tatsuta, Tomohiro; Morita, Yoshio; Takemura, Motohiko

2012-01-01

397

Observational Studies and a Statistical Early Warning of Surface Ozone Pollution in Tangshan, the Largest Heavy Industry City of North China  

PubMed Central

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

Li, Pei; Xin, Jinyuan; Bai, Xiaoping; Wang, Yuesi; Wang, Shigong; Liu, Shixi; Feng, Xiaoxin

2013-01-01

398

THE SCHMIDT-KENNICUTT LAW OF MATCHED-AGE STAR-FORMING REGIONS; Pa{alpha} OBSERVATIONS OF THE EARLY-PHASE INTERACTING GALAXY TAFFY I  

SciTech Connect

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.

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

399

Deep coastal marine taphonomy: investigation into carcass decomposition in the saanich inlet, british columbia using a baited camera.  

PubMed

Decomposition and faunal colonization of a carcass in the terrestrial environment has been well studied, but knowledge of decomposition in the marine environment is based almost entirely on anecdotal reports. Three pig carcasses were deployed in Saanich Inlet, BC, over 3 years utilizing Ocean Network Canada's VENUS observatory. Each carcass was deployed in late summer/early fall at 99 m under a remotely controlled camera and observed several times a day. Dissolved oxygen, temperature, salinity, density and pressure were continuously measured. Carcass 1 was immediately colonized by Munida quadrispina, Pandalus platyceros and Metacarcinus magister, rapidly scavenged then dragged from view by Day 22. Artifacts specific to each of the crustaceans' feeding patterns were observed. Carcass 2 was scavenged in a similar fashion. Exposed tissue became covered by Orchomenella obtusa (Family Lysianassidae) which removed all the internal tissues rapidly. Carcass 3 attracted only a few M. quadrispina, remaining intact, developing a thick filamentous sulphur bacterial mat, until Day 92, when it was skeletonized by crustacea. The major difference between the deployments was dissolved oxygen levels. The first two carcasses were placed when oxygen levels were tolerable, becoming more anoxic. This allowed larger crustacea to feed. However, Carcass 3 was deployed when the water was already extremely anoxic, which prevented larger crustacea from accessing the carcass. The smaller M. quadrispina were unable to break the skin alone. The larger crustacea returned when the Inlet was re-oxygenated in spring. Oxygen levels, therefore, drive the biota in this area, although most crustacea endured stressful levels of oxygen to access the carcasses for much of the time. These data will be valuable in forensic investigations involving submerged bodies, indicating types of water conditions to which the body has been exposed, identifying post-mortem artifacts and providing realistic expectations for recovery divers and families of the deceased. PMID:25329759

Anderson, Gail S; Bell, Lynne S

2014-01-01

400

Deep Coastal Marine Taphonomy: Investigation into Carcass Decomposition in the Saanich Inlet, British Columbia Using a Baited Camera  

PubMed Central

Decomposition and faunal colonization of a carcass in the terrestrial environment has been well studied, but knowledge of decomposition in the marine environment is based almost entirely on anecdotal reports. Three pig carcasses were deployed in Saanich Inlet, BC, over 3 years utilizing Ocean Network Canada’s VENUS observatory. Each carcass was deployed in late summer/early fall at 99 m under a remotely controlled camera and observed several times a day. Dissolved oxygen, temperature, salinity, density and pressure were continuously measured. Carcass 1 was immediately colonized by Munida quadrispina, Pandalus platyceros and Metacarcinus magister, rapidly scavenged then dragged from view by Day 22. Artifacts specific to each of the crustaceans’ feeding patterns were observed. Carcass 2 was scavenged in a similar fashion. Exposed tissue became covered by Orchomenella obtusa (Family Lysianassidae) which removed all the internal tissues rapidly. Carcass 3 attracted only a few M. quadrispina, remaining intact, developing a thick filamentous sulphur bacterial mat, until Day 92, when it was skeletonized by crustacea. The major difference between the deployments was dissolved oxygen levels. The first two carcasses were placed when oxygen levels were tolerable, becoming more anoxic. This allowed larger crustacea to feed. However, Carcass 3 was deployed when the water was already extremely anoxic, which prevented larger crustacea from accessing the carcass. The smaller M. quadrispina were unable to break the skin alone. The larger crustacea returned when the Inlet was re-oxygenated in spring. Oxygen levels, therefore, drive the biota in this area, although most crustacea endured stressful levels of oxygen to access the carcasses for much of the time. These data will be valuable in forensic investigations involving submerged bodies, indicating types of water conditions to which the body has been exposed, identifying post-mortem artifacts and providing realistic expectations for recovery divers and families of the deceased. PMID:25329759

Anderson, Gail S.; Bell, Lynne S.

2014-01-01

401

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

NASA Astrophysics Data System (ADS)

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 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. 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 proxiesas they mainly reflect the formation of humic acids through humifcation and to a~lesser extend mass loss during mineralization.

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

2013-11-01

402

Determining the degree of peat decomposition - A comparison of different methods  

NASA Astrophysics Data System (ADS)

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 R