bluuebunny/crossref_metadata_2025_split huggingface dataset:
A magnified beam algorithm to determine the coupling ratios of R/C coupled shear wall
Authors: Doran Bilge 
Published: March 2009

AbstractThe structural behaviour of a coupled shear wall (CSW) is greatly affected by the geometrical and mechanical properties of the coupling beams. The coupling ratio (r) is defined to represent the proportion of overturning moment resisted by each individual shear wall. The coupling ratio (r) is considered to be a key parameter in the nonlinear analysis and design of CSWs. In this study, the coupling ratios are determined on the basis of magnified beam analysis, using a statistical approach. An adequate number of CSWs have been selected with varying geometrical and mechanical properties, and the coupling ratios have been determined for each case using a magnified beam algorithm. The structural analyses have been also performed by the finite element modelling, and relationships for the estimation of the coupling ratios are provided using nonlinear regression analyses. The magnified beam approach adapted in this study is therefore proven to be capable of providing accurate and practical estimates for the coupling ratios of R/C CSWs. The results are quite promising for further research of any expanded data sets. Copyright © 2009 John Wiley & Sons, Ltd.
Virus Structures, Stellations, Spikes, and Rods
Authors: Andersson Sten 
Published: March 2009

AbstractWe show that the spike structures of viruses accurately can be described as stellations of polyhedra using exponential GD functions and also the fundamental theorem of algebra. The structures of foot‐and‐mouth disease virus, human Coxsackie viruses B3 and A21, polio virus, human rhinovirus 16 (common cold), human hepatitis B virus, herpes virus, Sindbis virus, Semliki virus, and echoviruses 1, 7 and 12 are discussed. Again methods from inorganic solid‐state chemistry are very useful in the descriptions.
Nobel‐Metal Centered Polycations [Au@Bi10]5+ or [Pd@Bi10]4+ Embedded in Halogenido‐Bismuthate(III)‐Stannate(II) Frameworks
Authors: Wahl Bernhard , Erbe Manuela , Gerisch Alexander , Kloo Lars , Ruck Michael 
Published: March 2009

AbstractThe metal‐rich halogenides AuBi14–δSn2+δX21–δ (δ ≈ 0.4) and PdBi15–δSn1+δX21–δ (δ ≈ 0.6) with X = Cl, Br were crystallized from melts of the metals and BiX3. In the rhombohedral structures (space group R; a ≈ 1050 pm; α ≈ 94°), noble‐metal centered pentagonal antiprisms [Au@Bi10]5+ resp. [Pd@Bi10]4+ are embedded in halogenidometallate frameworks ∞3[Bi4–δSn2+δX21–δ]5– resp. ∞3[Bi5–δSn1+δX21–δ]4–. Mixed BiIII/SnII site occupation allows the framework to adopt different charges. Further exchange of BiIIIX3 against SnIIX2 results in vacancies (δ) on the position of an isolated halide ion. In quantum chemical calculations the naked metal‐clusters are found to be stable in D5d symmetry with interatomic distances close to the observed ones. The significance of interactions between the Wade‐type host cluster Bi104+ and the closed‐subshell guest atoms Au+ or Pd0 is reflected in the molecular orbital diagram, the population analyses and the ELI‐D.
Using remote sensing to quantify aeolian transport and estimate the age of the terminal dune field Dunas Pampa Blanca in southern Peru
Authors: Hesse Ralf 
Published: March 2009

AbstractAeolian dunes are widely used to reconstruct paleoenvironmental conditions. However, terminal dune fields (ergs) in the coastal desert of southern Peru – where information regarding Quaternary paleoenvironmental conditions is very limited – have until now not been used for paleoenvironmental reconstructions and the time depth of their accumulation is unknown. Here, different estimates are derived to constrain the time depth recorded in the Dunas Pampa Blanca, a terminal dune field in coastal southern Peru. Dune field age is calculated using the volume of the Dunas Pampa Blanca and (i) recent aeolian transport rate in migrating transverse dunes feeding the Dunas Pampa Blanca (derived from digital processing of sequential Landsat and Quickbird images) and (ii) limitations posed by recent fluvial sediment supply to the source of aeolian transport. The resulting maximum age estimate of 70 ± 8 ka (from aeolian transport) compares with a minimum age estimate of 4–75 ka (from sediment supply). However, a minimum age estimate of 110–450 ka is deduced from the tectonic and topographic evolution of the region. This discrepancy contradicts the hypothesis of late Quaternary stability in the Peruvian coastal desert and indicates that recent conditions of aeolian sediment supply and transport are not representative for the late Quaternary.
Self focusing of a laser pulse in plasma with periodic density ripple
Authors: Kaur Sukhdeep , Sharma A.K. 
Published: March 2009

AbstractPropagation of an intense laser pulse in plasma with a periodically modulated density is considered using envelope equations. The laser induces modifications of the plasma refractive indexviarelativistic and ponderomotive nonlinearities. In the region of high plasma density, the self focusing effect of nonlinearity suppresses the diffraction divergence, and the laser converges. As the beam enters into the low density region, the diffraction tends to diverge it offsetting the convergence due to the curvature it has acquired. For a given set of plasma parameters, there is a critical power of the laser above which it propagates in a periodically focused manner. Below this power the laser undergoes overall divergence. At substantially higher powers, the laser beam continues to converge until the saturation effect of nonlinearity suppresses the self focusing and diffraction predominates. The effect of density ripple is to cause overall increase in the self focusing length. The minimum spot size decreases with the wave number of the ripple.
A study on fabrication, manipulation and survival of cryogenic targets required for the experiments at the Facility for Antiproton and Ion Research: FAIR
Authors: Koresheva E.R. , Aleksandrova I.V. , Koshelev E.L. , Nikitenko A.I. , Timasheva T.P. , Tolokonnikov S.M. , Belolipetskiy A.A. , Kapralov V.G. , Sergeev V. Yu. , Blazevic A. , Weyrich K. , Varentsov D. , Tahir N.A. , Udrea S. , Hoffmann D.H.H. 
Published: March 2009

AbstractCylindrical cryogenic targets are required to carry out the Laboratory Planetary Science scheme of the experiments of the High Energy Density matter Generated by Heavy Ion Beams collaboration at FAIR. In this paper, for the first time a thorough analysis of the problem of such targets' fabrication, delivery and positioning in the center of the experimental chamber has been made. Particular attention is paid to the issue of a specialized cryogenic system creation intended for rep-rate supply of the High Energy Density matter Generated by Heavy Ion Beams experiments with the cylindrical cryogenic targets.
Risk of transmitting meningococcal infection by transient contact on aircraft and other transport
Authors: RACHAEL T. , SCHUBERT K. , HELLENBRAND W. , KRAUSE G. , STUART J. M. 
Published: March 2009

SUMMARYContact tracing of persons with meningococcal disease who have travelled on aeroplanes or other multi-passenger transport is not consistent between countries. We searched the literature for clusters of meningococcal disease linked by transient contact on the same plane, train, bus or boat. We found reports of two clusters in children on the same school bus and one in passengers on the same plane. Cases within each of these three clusters were due to strains that were genetically indistinguishable. In the aeroplane cluster the only link between the two cases was through a single travel episode. The onset of illness (2 and 5 days after the flight) is consistent with infection from an unidentified carrier around the time of air travel. In contrast to the established risk of transmission from a case of tuberculosis, it is likely that the risk from a case of meningococcal disease to someone who is not identified as a close contact is exceedingly low. This should be considered in making international recommendations for passenger contact tracing after a case of meningococcal disease on a plane or other multi-passenger transport.
Habitat utilisation by the threatened Sichuan Partridge Arborophila rufipectus: consequences for managing newly protected areas in southern China
Authors: BO DAI , DOWELL SIMON D. , GARSON PETER J. , FEN-QI HE 
Published: March 2009

SummaryA number of former forest farms in southern Sichuan province, south-west China have been designated as protected areas following the 1998 logging ban in the upper Yangtze basin. These are within the range of the endemic Sichuan Partridge Arborophila rufipectus which has a fragmented distribution in the remnant broadleaf forests of this region, and is currently listed as ‘Endangered’ by IUCN. The design of a robust conservation plan for this species has been hampered by a lack of knowledge about its habitat preferences in a heavily modified environment. To remedy this, ranging behaviour and habitat utilization by this species was studied through a combination of a call count method and radio tracking of individual birds. The results indicate that A. rufipectus significantly prefers primary and older planted secondary broadleaf forest compared to forest degraded by human activity or scrub. Individual birds were found on the upper parts of slopes and made particular use of areas with a dense canopy and open understorey, whilst avoiding the lower slopes and areas close to trails where human disturbance is likely to be greater. The ongoing conservation programme for this partridge species is based on these findings and includes further protected area designations and management plans, the establishment of new forest corridors, and better control of hunting and other forms of forest exploitation.
Measuring the lifecycle of baryonic matter in the Large Magellanic Cloud with the Spitzer SAGE-LMC survey
Authors: Meixner Margaret , Bernard Jean-Philippe , Blum Robert D. , Indebetouw Remy , Reach William , Srinivasan Sundar , Sewilo Marta , Whitney Barbara A. 
Published: March 2009

AbstractThe recycling of matter between the interstellar medium (ISM) and stars are key evolutionary drivers of a galaxy's baryonic matter. The Spitzer wavelengths provide a sensitive probe of circumstellar and interstellar dust and hence, allow us to study the physical processes of the ISM, the formation of new stars and the injection of mass by evolved stars and their relationships on the galaxy-wide scale of the LMC. Due to its proximity, favorable viewing angle, multi-wavelength information, and measured tidal interactions with the Small Magellanic Cloud (SMC), the LMC is uniquely suited for surveying the agents of a galaxy's evolution (SAGE), the ISM and stars. The SAGE-LMC project is measuring these key transition points in the life cycle of baryonic matter in the LMC. Here we present a connective view of the preliminary quantities estimated from SAGE-LMC for the total mass of the ISM, the galaxy wide star formation rate and the current stellar mass loss return. For context, we compare these numbers to the LMC's stellar mass.
Significant new planetary nebula discoveries as powerful probes of the LMC
Authors: Reid Warren A. , Parker Quentin A. 
Published: March 2009

AbstractOur discovery and analysis of 452 new planetary nebulae (PNe) in the Large Magellanic Cloud (LMC) has tripled the number of known LMC PNe, providing a powerful new resource for probing the kinematics of the LMC as well as contributing fresh insight into the PN luminosity function (PNLF) which we now extend to over 10 magnitudes in [O iii] and Hα. These discoveries have resulted from a new, deep (R ≡ 22), high resolution Hα map of the central 25 deg2 of the LMC, achieved by a process of multi-exposure median co-addition of a dozen 2-hour exposures. The resulting map is at least 1 magnitude deeper than the best wide-field narrow-band LMC images currently available and has proven a major resource for the discovery of emission objects of all kinds. As a result, the near complete sample of the PN population in the central 25 deg2 of the LMC has permitted truly meaningful quantitative determinations of the PNLF, distribution, abundances and kinematics. We briefly describe the importance of these PN discoveries, the additional spectroscopic confirmation of >2,000 compact emission sources, flux calibration, the newly derived electron temperatures and electron densities.
The spatial evolution of stellar structures in the LMC/SMC
Authors: Bastian Nate , Gieles Mark , Ercolano Barbara , Gutermuth Robert 
Published: March 2009

AbstractWe present an analysis of the spatial distribution of various stellar populations within the Large and Small Magellanic Clouds. We use optically selected stellar samples with mean ages between ~9 and ~1000 Myr, and existing stellar cluster catalogues to investigate how stellar structures form and evolve within the LMC/SMC. We use two statistical techniques to study the evolution of structure within these galaxies, the Q-parameter and the two-point correlation function (TPCF). In both galaxies we find the stars are born with a high degree of substructure (i.e. are highly fractal) and that the stellar distribution approaches that of the “background” population on timescales similar to the crossing times of the galaxy (~ 80 Myr & ~ 150 Myr for the SMC/LMC respectively). By comparing our observations to simple models of structural evolution we find that “popping star clusters” do not significantly influence structural evolution in these galaxies. Instead we argue that general galactic dynamics are the main drivers, and that substructure will be erased in approximately the crossing time, regardless of spatial scale, from small clusters to whole galaxies. This can explain why many young Galactic clusters have high degrees of substructure, while others are smooth and centrally concentrated. We conclude with a general discussion on cluster “infant mortality”, in an attempt to clarify the time/spatial scales involved.
Line of sight depth of the Large and Small Magellanic Clouds
Authors: Subramaniam Annapurni , Subramaniam Smitha 
Published: March 2009

AbstractWe used the red clump stars from the Optical Gravitational Lensing Experiment (OGLE II) survey and the Magellanic Cloud Photometric Survey (MCPS), to estimate the line-of-sight depth. The observed dispersion in the magnitude and colour distribution of red clump stars is used to estimate the line-of-sight depth, after correcting for the contribution due to other effects. This dispersion due to depth, has a range from minimum dispersion that can be estimated, to 0.46 mag (a depth of 500 pc to 10.44 kpc), in the LMC. In the case of the SMC, the dispersion ranges from minimum dispersion to 0.35 magnitude (a depth of 665 pc to 9.53 kpc). The thickness profile of the LMC bar indicates that it is flared. The average depth in the bar region is 4.0 ± 1.4 kpc. The halo of the LMC (using RR Lyrae stars) is found to have larger depth compared to the disk/bar, which supports the presence of an inner halo for the LMC. The large depth estimated for the LMC bar and the disk suggests that the LMC might have had minor mergers. In the case of the SMC, the bar depth (4.90 ± 1.23 kpc) and the disk depth (4.23 ± 1.48 kpc) are found to be within the standard deviations. We find evidence for an increase in depth near the optical center (up to 9 kpc). On the other hand, the estimated depth for the halo (RR Lyrae stars) and disk (RC stars) for the bar region of the SMC is found to be similar. Thus, increased depth and enhanced stellar as well as H i density near the optical center suggests that the SMC may have a bulge.
The state of molecular gas in the Small Magellanic Cloud
Authors: Leroy Adam K. , Bolatto Alberto D. , Rosolowsky Erik , Stanimirović Snežana , Mizuno Norikazu , Bot Caroline , Israel Frank , Walter Fabian , Blitz Leo 
Published: March 2009

AbstractWe compare the resolved properties of giant molecular clouds (GMCs) in the Small Magellanic Cloud (SMC) and other low mass galaxies to those in more massive spirals. When measured using CO line emission, differences among the various populations of GMCs are fairly small. We contrast this result with the view afforded by dust emission in the Small Magellanic Cloud. Comparing temperature-corrected dust opacity to the distribution of Hisuggests extended envelopes of CO-free H2, implying that CO traces only the highest density H2in the SMC. Including this CO-free H2, the gas depletion time, H2-to-Hiratio, and H2-to-stellar mass/light ratio in the SMC are all typical of those found in more massive irregular galaxies.
The Spitzer spectroscopic survey of the Small Magellanic Cloud: polycyclic aromatic hydrocarbon emission from SMC star-forming regions
Authors: Sandstrom Karin M. , Bolatto Alberto D. , Stanimirović Snežana , Smith J. D. T. , van Loon Jacco Th. , Leroy Adam K. 
Published: March 2009

AbstractBecause of its proximity, the Small Magellanic Cloud provides a unique opportunity to map the polycyclic aromatic hydrocarbon (PAH) emission from photo-dissociation regions (PDRs) in a low-metallicity (12 + log(O/H) ~ 8) galaxy at high spatial resolution in order to learn about their abundance and physical state. We present mid-IR spectral mapping observations of star-forming regions in the Small Magellanic Cloud obtained as part of the Spitzer Spectroscopic Survey of the SMC (S4MC) project. These observations allow us to map the distribution of PAH emission in these regions and the measure the variation of PAH band strengths with local physical conditions. In these proceedings we discuss preliminary results on the physical state of the PAHs, in particular their ionization fraction.
Properties of star forming regions in the Magellanic Clouds
Authors: Rubio Mónica 
Published: March 2009

AbstractUnderstanding the process of star formation in low metallicity systems is one of the key studies in the early stages of galaxy evolution. The Magellanic Clouds, being the nearest examples of low metallicity systems, allow us to study in detail their star forming regions. As a consequence of their proximity we can resolve the molecular clouds and the regions of star formation individually. Therefore we can increase our knowledge of the interaction of young luminous stars with their environment. We will present results of multiwavelenghts studies of LMC and SMC massive star forming regions, which includes properties of the cold molecular gas, the embedded young population associated with molecular clouds, and the interaction of newly born stars with the surrounding interstellar medium, based on ASTE and APEX submillimeter observations complemented high sensitivity NIR groud based observations and Spitzer results.
Multiple stellar populations in massive LMC star clusters
Authors: Mackey A. D. , Nielsen P. Broby , Ferguson A. M. N. , Richardson J. C. 
Published: March 2009

AbstractThe recent discovery of multiple stellar populations in massive Galactic globular clusters poses a serious challenge for models of star cluster formation and evolution. A new angle on this problem is being provided by rich intermediate-age clusters in the Magellanic Clouds. In this contribution we describe the discovery of three such LMC clusters with peculiar main-sequence turn-off morphologies. The simplest interpretation of our observations is that each of these three clusters is comprised of two or more stellar populations spanning an age interval of ~300 Myr. Surprisingly, such features may not be unusual in this type of cluster.
Gemini/GMOS detection of stellar velocity variations in the ionising cluster of 30 Dor
Authors: Bosch Guillermo , Terlevich Elena , Terlevich Roberto 
Published: March 2009

AbstractWe have analysed spectra obtained with the Gemini Multi Object Spectrograph (GMOS) for more than 50 stars in the ionising cluster of 30 Doradus during a seven epochs observing campaign at Gemini South. We derive a binary candidate rate of about 50%, which is however consistent with an intrinsic 100% binary rate among massive stars. After decontaminating the sample from the stars that show binary orbital motions, we were able to calculate the “true” cluster velocity dispersion and found it to be about 8 km s−1. This value implies a virial mass of about 4.5 × 105 M⊙ which is consistent with previous photometric mass determinations therefore suggesting that NGC 2070 is a firm candidate for a future globular cluster.
The properties of early-type stars in the Magellanic Clouds
Authors: Evans Christopher J. 
Published: March 2009

AbstractThe past decade has witnessed impressive progress in our understanding of the physical properties of massive stars in the Magellanic Clouds, and how they compare to their cousins in the Galaxy. I summarise new results in this field, including evidence for reduced mass-loss rates and faster stellar rotational velocities in the Clouds, and their present-day compositions. I also discuss the stellar temperature scale, emphasizing its dependence on metallicity across the entire upper-part of the Hertzsprung-Russell diagram.
Supernova remnants in the Magellanic Clouds
Authors: Williams Rosa N. M. 
Published: March 2009

AbstractAt the 1998 IAU Symposium on the Magellanic Clouds, Dr. Robert Petre observed that we were reaching a time where it was possible “to study the MC SNRs at a level of detail comparable with many Galactic remnants”, while retaining the benefits of a global view in the MCs. Over the past decade, many researchers have taken advantage of these newly accessible populations. New MC-wide surveys at various wavelengths have enabled broader searches for SNR candidates, extending our census of MC SNRs to less prominent objects — older SNRs, SNRs in complex regions, et cetera. The use of light-echoes has provided a new avenue to probe young SNRs. Higher spatial and spectral resolutions in many wavelength regimes have enabled detailed studies of individual remnants, revealing progenitor types, pulsar-wind nebulae, expansion details, and environmental effects.Perhaps the newest conceptual development is the increasing use of the MC SNRs to study physical problems of wider significance to many fields of astronomy. For example, researchers have examined the energy and hot gas inputs of MC SNRs to the ISM, including their collective effects within superbubbles, in order to evaluate their effects on stellar feedback cycles in a galaxy. Other scientists have investigated the fraction of SNR energies going to the acceleration of cosmic rays, which has significant implications for the role of SNRs in cosmic-ray production. Most recently, the onslaught of Spitzer data has led to new exploration of dust in MC SNRs, allowing us to probe dust creation, depletion, and destruction in the MC SNR populations. In summary, the study of SNRs in the MCs appears to have “come of age” over the past decade, becoming a mature field with rich potential for future scientific work.
The Magellanic Group and the Seven Dwarfs
Authors: D'Onghia Elena , Lake George 
Published: March 2009

AbstractThe Magellanic Clouds were the largest members of a group of dwarf galaxies that entered the Milky Way (MW) halo at late times. This group, dominated by the LMC, contained ~4% of the mass of the Milky Way prior to its accretion and tidal disruption, but ≈70% of the known dwarfs orbiting the MW. Our theory addresses many outstanding problems in galaxy formation associated with dwarf galaxies. First, it can explain the planar orbital configuration populated by some dSphs in the MW. Second, it provides a mechanism for lighting up a subset of dwarf galaxies to reproduce the cumulative circular velocity distribution of the satellites in the MW. Finally, our model predicts that most dwarfs will be found in association with other dwarfs. The recent discovery of Leo V (Belokurov et al. 2008), a dwarf spheroidal companion of Leo IV, and the nearby dwarf associations supports our hypothesis.