cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Definitions- und Re-Definitionsprozesse im Wissensmanagement. Eine Falldarstellung zur Sensibilisierung und Initiierung
Creators: name: Clases, Christoph
name: Moser, Karin S.
name: Wehner, Theo
Publisher: name: TUHH Universitätsbibliothek
Year: 2001
Subjects: subject: 85.20:Betriebliche Information und Kommunikation
subject: Wissensmanagement
subject: Arbeitspsychologie
subject: 85.20
subject: 330

description: Die Auseinandersetzung mit dem Thema Wissensmanagement im Kontext einer vornehmlich betriebswissenschaftlich geführten Diskussion kann als ein bisher vor allem auf konzeptueller Ebene geführter Diskurs eingeschätzt werden. Es fehlen demgegenüber weitgehend systematisch reflektierte betriebliche Erfahrungen zum Thema. Anhand einer Falldarstellung zur Initiierung von Wissensmanagement in einem mit Forschungs- und Entwicklungsprojekten befassten mittelständischen Unternehmen in der Schweiz wird das Thema Wissensmanagement aus arbeitspsychologischer Perspektive als Problematik der Analyse und Gestaltung wissensorientierter Kooperation reformuliert. Die Falldarstellung veranschaulicht Fallstricke und Meilensteine auf dem Weg zu einer konkreten Initiierung von Wissensmanagement. Dabei wird ein Schwergewicht auf Prozesse der betrieblichen Re-Definition des zunächst einmal abstrakten Themas Wissensmanagement gelegt. Der methodischen Unterstützung von Sensibilisierungsprozessen für das Thema Wissen kommt hierbei eine besondere Bedeutung zu. Es werden Wege aufgezeigt, Prozesse der Explikation unterschiedlicher Akteursperspektiven wissenschaftlich zu reflektieren und zugleich – im Sinne einer dialog- und interventionsorientierte Forschungsstrategie – praktisch zu unterstützen. An einem konkreten Fall werden so Möglichkeiten wie Grenzen einer Verschränkung individueller und kollektiver Re-Definitionsprozesse dargestellt. Innerbetriebliche, wie forschungsbezogene Faktoren, die zu einer erfolgreichen Initiierung des Projekts geführt haben, werden anhand konkreter Ereignisse und Akteurskonstellationen dargestellt und abschliessend auf einer Metaebene diskutiert.
FT-IR of Sample (N-(β-ethoxypropionitrile)-N,N-bis(2-hydroxyethylethoxy) fatty amide) after adsorption on to steel surface from Synthesis and evaluation of corrosion inhibitory and adsorptive properties of N-(β-ethoxypropionitrile-N, N-bis(2-hydroxyethylethoxy) fatty amide
Creators: name: Rakhymbay, Gulmira
name: Jumanova, Raigul
name: Avchukir, Khaisa
name: Bakhytzhan, Yeldana
name: Argimbayeva, Akmaral
name: Burkitbayeva, Bibisara
name: Turmukhanova, Mirgul
name: Vacandio, Florence
name: Adeloye, Adewale
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: 90499 Chemical Engineering not elsewhere classified
subject: FOS: Chemical engineering
subject: 30699 Physical Chemistry not elsewhere classified
subject: FOS: Chemical sciences

description: The present study reports a synthetic condensation process of a vegetable oil (waste) reacted with triethanolamine, maleic anhydride and acrylonitrile in (1 : 1.2 : 2 : 1) mole ratios to obtain N-(β-ethoxypropionitrile)-N,N-bis(2-hydroxyethylethoxy) fatty amide as a major inhibitory product. Corrosion property of steel in a 3% NaCl solution in the presence of a potential inhibitor was investigated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. These methods gave consistent results, from which it is noticeable that inhibition efficiency increases with the increasing concentration of the inhibitor. Gravimetric studies show an increase in the sample mass at an inhibitor concentration of 10 mM, indicative of adsorbed film formation on the surface. The polarization curve results showed that the compound demonstrates itself as an anodic-type inhibitor. A rise in polarization resistance values in the EIS measurements also confirmed that the compound acts as an effective inhibitor of steel corrosion. Furthermore, the R(CR)(QR) equivalent circuit was used to interpret the results obtained in the investigation of the corrosion behaviour of steel in solution with an inhibitor. The standard adsorption free energies calculated from the Langmuir isotherm indicate that adsorption takes place by physical and chemical mechanisms. The presence of adsorbed protective film was confirmed by FT-IR spectrum and SEM micrographs.
Dynamics of photo-activated Coulomb complexes
Creators: name: Gnodtke, Christian
name: Saalmann, Ulf
name: Rost, Jan-Michael
Publisher: name: arXiv
Year: 2010
Subjects: subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Intense light with frequencies above typical atomic or molecular ionization potentials as provided by free-electron lasers couples many photons into extended targets such as clusters and biomolecules. This implies, in contrast to traditional multi-photon ionization, multiple single-photon absorption. Thereby, many electrons are removed from their bound states and either released or trapped if the target charge has become sufficiently large. We develop a simple model for this photo activation to study electron migration and interaction. It satisfies scaling relations which help to relate quite different scenarios. To understand this type of multi-electron dynamics on very short time scales is vital for assessing the radiation damage inflicted by that type of radiation and to pave the way for coherent diffraction imaging of single molecules.
description: 14 pages, 6 figures, 1 table
The nature of X-ray absorbed QSOs
Creators: name: Page, M. J.
name: Carrera, F. J.
name: Stevens, J. A.
name: Ebrero, J.
name: Blustin, A. J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: There exists a significant population of broad line, z~2 QSOs which have heavily absorbed X-ray spectra. Follow up observations in the submillimetre show that these QSOs are embedded in ultraluminous starburst galaxies, unlike most unabsorbed QSOs at the same redshifts and luminosities. Here we present X-ray spectra from XMM-Newton for a sample of 5 such X-ray absorbed QSOs that have been detected at submillimetre wavelengths. We also present spectra in the restframe ultraviolet from ground based telescopes. All 5 QSOs are found to exhibit strong C IV absorption lines in their ultraviolet spectra with equivalent width > 5 Angstroms. The X-ray spectra are inconsistent with the hypothesis that these objects show normal QSO continua absorbed by low-ionization gas. Instead, the spectra can be modelled successfully with ionized absorbers, or with cold absorbers if they posess unusually flat X-ray continuum shapes and unusual optical to X-ray spectral energy distributions. We show that the ionized absorber model provides the simplest, most self-consistent explanation for their observed properties. We estimate that the fraction of radiated power that is converted into kinetic luminosity of the outflowing winds is typically ~4 per cent, in agreement with recent estimates for the kinetic feedback from QSOs required to produce the M - sigma relation, and consistent with the hypothesis that the X-ray absorbed QSOs represent the transition phase between obscured accretion and the luminous QSO phase in the evolution of massive galaxies.
description: Accepted for publication in MNRAS
Post-Capture Evolution of Potentially Habitable Exomoons
Creators: name: Porter, Simon B.
name: Grundy, William M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The satellites of extrasolar planets (exomoons) have been recently proposed as astrobiological targets. Since giant planets in the habitable zone are thought to have migrated there, it is possible that they may have captured a former terrestrial planet or planetesimal. We therefore attempt to model the dynamical evolution of a terrestrial planet captured into orbit around a giant planet in the habitable zone of a star. We find that approximately half of loose elliptical orbits result in stable circular orbits over timescales of less than a few million years. We also find that those orbits are mostly low-inclination, but have no prograde/retrograde preference. In addition, we calculate the transit timing and duration variations for the resulting systems, and find that potentially habitable Earth-mass exomoons should be detectable.
description: 5 pages, 3 figures, 2 tables, accepted to ApJ Letters
Wissensmanagement als Integrationsmetapher. Eine Fallstudie zur Situation von Führungskräften und deren Haltung zur Ressource Wissen
Creators: name: Jarowoy, Maria
name: Dick, Michael
Publisher: name: TUHH Universitätsbibliothek
Year: 2001
Subjects: subject: 85.20:Betriebliche Information und Kommunikation
subject: Wissensmanagement
subject: Arbeitspsychologie
subject: Informationsmanagement
subject: 85.20
subject: 330

description: Dieser Beitrag entstand im Rahmen eines Anwendungsprojektes zum Wissensmanagement
 mit einem Luftfahrtunternehmen. Im Rahmen dieses Forschungsprojekts bot es sich an, der Projektauswertung und den Mitarbeiter-Befragungen eine Untersuchung der Perspektive von mittleren Führungskräften hinzuzufügen.
FT-IR of compound (III) N-(β-ethoxypropionitrile)-N,N-bis(2-hydroxyethylethoxy) fatty amide from Synthesis and evaluation of corrosion inhibitory and adsorptive properties of N-(β-ethoxypropionitrile-N, N-bis(2-hydroxyethylethoxy) fatty amide
Creators: name: Rakhymbay, Gulmira
name: Jumanova, Raigul
name: Avchukir, Khaisa
name: Bakhytzhan, Yeldana
name: Argimbayeva, Akmaral
name: Burkitbayeva, Bibisara
name: Turmukhanova, Mirgul
name: Vacandio, Florence
name: Adeloye, Adewale
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: 90499 Chemical Engineering not elsewhere classified
subject: FOS: Chemical engineering
subject: 30699 Physical Chemistry not elsewhere classified
subject: FOS: Chemical sciences

description: The present study reports a synthetic condensation process of a vegetable oil (waste) reacted with triethanolamine, maleic anhydride and acrylonitrile in (1 : 1.2 : 2 : 1) mole ratios to obtain N-(β-ethoxypropionitrile)-N,N-bis(2-hydroxyethylethoxy) fatty amide as a major inhibitory product. Corrosion property of steel in a 3% NaCl solution in the presence of a potential inhibitor was investigated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. These methods gave consistent results, from which it is noticeable that inhibition efficiency increases with the increasing concentration of the inhibitor. Gravimetric studies show an increase in the sample mass at an inhibitor concentration of 10 mM, indicative of adsorbed film formation on the surface. The polarization curve results showed that the compound demonstrates itself as an anodic-type inhibitor. A rise in polarization resistance values in the EIS measurements also confirmed that the compound acts as an effective inhibitor of steel corrosion. Furthermore, the R(CR)(QR) equivalent circuit was used to interpret the results obtained in the investigation of the corrosion behaviour of steel in solution with an inhibitor. The standard adsorption free energies calculated from the Langmuir isotherm indicate that adsorption takes place by physical and chemical mechanisms. The presence of adsorbed protective film was confirmed by FT-IR spectrum and SEM micrographs.
A study of spatial encoding and decoding in MRI
Creators: name: Depew, Thomas Andrew
Publisher: name: University of British Columbia
Year: 2015

description: Spatial encoding is a key feature (perhaps the key feature) of Magnetic Resonance Imaging (MRI). Since the discovery that magnetic field gradients could be used to localize signal, researchers have sought methods to acquire higher quality images, with greater efficiency. This dissertation investigates three approaches for encoding and decoding the information of MRI to provide useful images for clinical diagnosis. Partial Parallel Imaging (PPI) introduced a framework that enabled faster data acquisition, allowing reduction in scan time or improved resolution. We present a regionally optimized implementation of the popular PPI technique GeneRalised Auto-calibrating Partial Parallel Acquisition (GRAPPA). The regional implementation provides images with lower data recovery error and reduced residual aliasing artifact. We assess a number of image quality metrics that would allow automated selection of the optimal reconstructed image. A number of physical quantities can be mapped via comparison of two images with different sensitivities. When the contrast between these images is smoothly varying, the information may be captured using only a fraction of the k-space data required for full image reconstruction. We present a technique to provide robust recovery of relative information maps between images from minimal k-space data. The effectiveness of the technique is demonstrated through application to phase contrast MRI data. Many MRI applications are limited by acquisition in 2D multislice mode. In this regime, the slice direction typically suffers lower resolution than the in-plane directions. We present three strategies to improve through-plane resolution. The relative merits of each technique are investigated, and the performance is quantified with standard measures. The implications of the potential artifacts resulting from each technique are discussed.
The Ubiquitous Radio Continuum Emission from the Most Massive Early-Type Galaxies
Creators: name: Brown, Michael J. I.
name: Jannuzi, Buell T.
name: Floyd, David J. E.
name: Mould, Jeremy R.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We have measured the radio continuum emission of 396 early-type galaxies brighter than K = 9, using 1.4 GHz imagery from the NRAO VLA Sky Survey, Green Bank 300-ft Telescope and 64-m Parkes Radio Telescope. For M_K < -24 early-type galaxies, the distribution of radio powers at fixed absolute magnitude spans 4 orders of magnitude and the median radio power is proportional to K-band luminosity to the power 2.78\pm0.16. The measured flux densities of M_K < -25.5 early-type galaxies are greater than zero in all cases. It is thus highly likely that the most massive galaxies always host an active galactic nucleus or have recently undergone star formation.
description: Accepted for publication in ApJ Letters. 5 pages, 4 figures and 1 table
Magnetic Ordering in V-Layers of the Superconducting System of Sr2VFeAsO3
Creators: name: Tatematsu, Shunichi
name: Satomi, Erika
name: Kobayashi, Yoshiaki
name: Sato, Masatoshi
Publisher: name: arXiv
Year: 2010
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Results of transport, magnetic, thermal, and 75As-NMR measurements are presented for superconducting Sr2VFeAsO3 with an alternating stack of FeAs and perovskite-like block layers. Although apparent anomalies in magnetic and thermal properties have been observed at ~150 K, no anomaly in transport behaviors has been observed at around the same temperature. These results indicate that V ions in the Sr2VO3-block layers have localized magnetic moments and that V-electrons do not contribute to the Fermi surface. The electronic characteristics of Sr2VFeAsO3 are considered to be common to those of other superconducting systems with Fe-pnictogen layers.
description: 4 pages, 4 figures, To appear in JPSJ 79 (2010) 123712
Star formation in 30 Doradus
Creators: name: De Marchi, Guido
name: Paresce, Francesco
name: Panagia, Nino
name: Beccari, Giacomo
name: Spezzi, Loredana
name: Sirianni, Marco
name: Andersen, Morten
name: Mutchler, Max
name: Balick, Bruce
name: Dopita, Michael A.
name: Frogel, Jay A.
name: Whitmore, Bradley C.
name: Bond, Howard
name: Clazetti, Daniela
name: Carollo, C. Marcella
name: Disney, Michael J.
name: Hall, Donald N. B.
name: Holtzman, Jon A.
name: Kimble, Randy A.
name: McCarthy, Patrick J.
name: O'Connell, Robert W.
name: Saha, Abhijit
name: Silk, Joseph I.
name: Trauger, John T.
name: Walker, Alistair R.
name: Windhorst, Rogier A.
name: Young, Erick T.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Using observations obtained with the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope (HST), we have studied the properties of the stellar populations in the central regions of 30 Dor, in the Large Magellanic Cloud. The observations clearly reveal the presence of considerable differential extinction across the field. We characterise and quantify this effect using young massive main sequence stars to derive a statistical reddening correction for most objects in the field. We then search for pre-main sequence (PMS) stars by looking for objects with a strong (> 4 sigma) Halpha excess emission and find about 1150 of them over the entire field. Comparison of their location in the Hertzsprung-Russell diagram with theoretical PMS evolutionary tracks for the appropriate metallicity reveals that about one third of these objects are younger than ~4Myr, compatible with the age of the massive stars in the central ionising cluster R136, whereas the rest have ages up to ~30Myr, with a median age of ~12Myr. This indicates that star formation has proceeded over an extended period of time, although we cannot discriminate between an extended episode and a series of short and frequent bursts that are not resolved in time. While the younger PMS population preferentially occupies the central regions of the cluster, older PMS objects are more uniformly distributed across the field and are remarkably few at the very centre of the cluster. We attribute this latter effect to photoevaporation of the older circumstellar discs caused by the massive ionising members of R136.
description: 15 pages, 12 figures. Accepted for publication in The Astrophysical Journal
School gardening, teaching, and a pedagogy of enclosures : threads of an arts-based métissage
Creators: name: Ostertag, Julia Kathleen
Publisher: name: University of British Columbia
Year: 2015

description: In conversation with a growing school gardening movement (Williams & Brown, 2012), this arts-based research draws on material feminist and posthumanist (Alaimo & Hekman, 2008; Barad, 2003; Haraway, 2004, 2008) scholarship to reconfigure what it means to become a teacher. In particular, I explore ‘becoming teachers together’ with a garden as a way to reimagine alternatives for the persistent and familiar figure of the teacher as a rational, autonomous individual working within the closed doors of the traditional classroom (Britzman, 2003; Jackson, 1990). Indigenous scholarship, particularly around gift giving (Kuokkanen, 2007) and decolonization (Gaztambide-Fernández, 2012), offers unsettling insights into human and nonhuman entanglements such as the ‘garden-as-teacher.’ In this work, I linger beside (Sedgwick, 2003) both the possibilities and impossibilities of teaching with gardens, compelled to respond (Simon, 2006) to the difficult history of school gardens, particularly during Nazi Germany and in the Canadian residential school system, and the etymological knots that link gardens with material and discursive practices of enclosure. The art theory and practices that shape this research are site-specific installation art (Augaitis & Ritter, 2008; Bishop, 2005, 2012; Bourriaud, 2002; Függe & Fleck, 2006; Kester, 2011), especially collaborations with Vancouver artist Sharon Kallis (Kallis, 2014) and an interview with Ron Benner (Benner, 2008). Responding to O’Donoghue’s (2010) provocation to consider classrooms as installations, I developed the installation series Threads sown, grown & given from April 2012 until August 2014 at The UBC Orchard Garden (a teaching and learning garden at the University of British Columbia) and in the teacher education building. The resulting métissage (Hasebe-Ludt, Chambers & Leggo, 2009) of narratives includes (a) the garden becoming a teacher, (b) student teachers becoming teachers during three research events related to the installation series, and (c) my own personal of becoming a teacher, scholar, and teacher educator. By attending to failure (Halberstam, 2011), this arts-based research creates conditions for what I term a ‘pedagogy of enclosures’ to engage with the ethical responsibilities and limitations of becoming teachers together, particularly in teacher education and garden-based education within the context of settler colonialism and the neoliberalization of the academy.
Protocol for field collection and preservation of eDNA samples, D4.3 of the H2020-funded project EnvMetaGen
Creators: name: Egeter, Bastian
name: Fonseca, Nuno A.
name: Paupério, Joana
name: Galhardo, Mafalda
name: Ferreira, Sónia
name: Oxelfelt, Fredrik
name: Aresta, Sandra
name: Vasconcelos, Sasha
name: Gil, Patrícia
name: Khalatbari, Leili
name: Filipe, Ana F.
name: Jarman, Simon
name: Beja, Pedro
Publisher: name: Zenodo
Year: 2018
Subjects: metabarcoding
field sampling

description: The overall goal of ERA Chair/EnvMetaGen project No 668981 is to expand the research and innovation potential of InBIO – Research network in Biodiversity and Evolutionary Biology, through the creation of an ERA Chair in Environmental Metagenomics. This field was selected as the focus of the ERA Chair, because Environmental DNA (eDNA) analysis is increasingly being used for biodiversity assessment, diet analysis, detection of rare or invasive species, population genetics and ecosystem functional analysis. In this context, the work plan of EnvMetaGen includes one work package dedicated to the Deployment of an eDNA Lab (WP4), which involves the training of InBIO researchers and technicians for implementing best practice protocols for the analysis of eDNA (Task 4.2). These protocols are essential for key application areas and to the development of research projects in association with business partners and other stakeholders, and thus to the strengthening of InBIO triple-helix initiatives (InBIO-Industry-Government; WP5). This report provides an overview of the current state of the art for collecting and preserving eDNA samples, with particular focus on vertebrate faecal samples, water samples and bulk invertebrate samples, which have been selected as key targets for the development of triple helix strategic initiatives (Task 5.3). The protocols already optimized and currently under development for the collection and preservation of eDNA samples are reported herein. Moreover, the future directions of sample collection and preservation at InBIO are discussed. This development was made possible through the recruitment of the ERA Chair team (WP2), secondments and Junior Researcher exchanges through the collaboration with international networks (WP3), an enhancement of computational infrastructure at InBIO (WP4) and participation of team members in workshops and conferences (WP6).

Together, Deliverables D4.2-D4.5 form a detailed account of the successful deployment of a fully functional eDNA lab under the EnvMetaGen project, and provide a valuable resource for eDNA practitioners in all spheres of the triple-helix model.
X-ray Flares of EV Lac: Statistics, Spectra, Diagnostics
Creators: name: Huenemoerder, David P.
name: Schulz, Norbert S.
name: Testa, Paola
name: Drake, Jeremy J.
name: Osten, Rachel A.
name: Reale, Fabio
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We study the spectral and temporal behavior of X-ray flares from the active M-dwarf EV Lac in 200 ks of exposure with the Chandra/HETGS. We derive flare parameters by fitting an empirical function which characterizes the amplitude, shape, and scale. The flares range from very short (<1 ks) to long (10 ks) duration events with a range of shapes and amplitudes for all durations. We extract spectra for composite flares to study their mean evolution and to compare flares of different lengths. Evolution of spectral features in the density-temperature plane shows probable sustained heating. The short flares are significantly hotter than the longer flares. We determined an upper limit to the Fe K fluorescent flux, the best fit value being close to what is expected for compact loops.
description: 9 pages; 9 figures; latex/emulateapj style; Submitted to The Astrophysical Journal
Composite THz materials using aligned metallic and semiconductor microwires, experiments and interpretation
Creators: name: Mazhorova, Anna
name: Gu, Jian Feng
name: Dupuis, Alexandre
name: Tsuneyuki, Ozaki
name: Paccianti, Marco
name: Morandotti, Roberto
name: Minamide, Hiroaki
name: Tang, Ming
name: Wang, Yuye
name: Ito, Hiromasa
name: Skorobogatiy, Maksim
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We report fabrication method and THz characterization of composite films containing either aligned metallic (tin alloy) microwires or chalcogenide As2Se3 microwires. The microwire arrays are made by stack-and-draw fiber fabrication technique using multi-step co-drawing of low-melting-temperature metals or semiconductor glasses together with polymers. Fibers are then stacked together and pressed into composite films. Transmission through metamaterial films is studied in the whole THz range (0.1-20 THz) using a combination of FTIR and TDS. Metal containing metamaterials are found to have strong polarizing properties, while semiconductor containing materials are polarization independent and could have a designable high refractive index. Using the transfer matrix theory, we show how to retrieve the complex polarization dependent refractive index of the composite films. We then detail the selfconsistent algorithm for retrieving the optical properties of the metal alloy used in the fabrication of the metamaterial layers by using an effective medium approximation. Finally, we study challenges in fabrication of metamaterials with sub-micrometer metallic wires by repeated stack-and-draw process by comparing samples made using 2, 3 and 4 consecutive drawings. When using metallic alloys we observe phase separation effects and nano-grids formation on small metallic wires.
A hybrid method for computing a smallest eigenvalue of a symmetric and positive definite Toeplitz matrix
Creators: name: Kostić, Aleksandra
name: Voß, Heinrich
Publisher: name: TUHH Universitätsbibliothek
Year: 2003
Subjects: subject: Toeplitz matrix
subject: eigenvalue problem
subject: hybrid method
subject: Nichtlineares Eigenwertproblem
subject: Toeplitz-Matrix
subject: 510
subject: 65F15:Eigenvalues, eigenvectors
subject: 65F15

description: In this paper we suggest a hybrid method for computing the smallest eigenvalue of a symmetric and positive definite Toeplitz matrix which takes advantage two types of methods, Newton's method for the characteristic polynomial and projection methods based on rational interpolation of the secular equation.
Covariant Closed String Coherent States
Creators: name: Hindmarsh, Mark
name: Skliros, Dimitri
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We give the first construction of covariant coherent closed string states, which may be identified with fundamental cosmic strings. We outline the requirements for a string state to describe a cosmic string, and using DDF operators provide an explicit and simple map that relates three different descriptions: classical strings, lightcone gauge quantum states and covariant vertex operators. The naive construction leads to covariant vertex operators whose existence requires a lightlike compactification of spacetime. When the lightlike compactified states in the underlying Hilbert space are projected out the resulting coherent states have a classical interpretation and are in one-to-one correspondence with arbitrary classical closed string loops.
description: 4 pages
Spatially Resolved PAH Emission Features in Nearby, Low Metallicity, Star-Forming Galaxies
Creators: name: Haynes, Korey
name: Cannon, John M.
name: Skillman, Evan D.
name: Jackson, Dale C.
name: Gehrz, Robert D.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Low-resolution, mid-infrared Spitzer/IRS spectral maps are presented for three nearby, low-metallicity dwarf galaxies (NGC 55, NGC 3109 and IC 5152) for the purpose of examining the spatial distribution and variation of polycyclic aromatic hydrocarbon (PAH) emission. The sample straddles a metallicity of 12+log(O/H)~8.0, a transition point below which PAH intensity empirically drops and the character of the interstellar medium changes. We derive quantitative radiances of PAH features and atomic lines on both global and spatially-resolved scales. The Spitzer spectra, combined with extensive ancillary data from the UV through the mid-infrared, allow us to examine changes in the physical environments and in PAH feature radiances down to a physical scale of 50 pc. We discuss correlations between various PAH emission feature and atomic line radiances. The (6.2 micron)/(11.3 micron), (7.7 micron)/(11.3 micron), (8.6 micron)/(11.3 micron), (7.7 micron)/(6.2 micron), and (8.6 micron)/(6.2 micron) PAH radiance ratios are found to be independent of position across all three galaxies, although the ratios do vary from galaxy to galaxy. As seen in other galaxies, we find no variation in the grain size distribution as a function of local radiation field strength. Absolute PAH feature intensities as measured by a ratio of PAH/(24 micron) radiances are seen to vary both positionally within a given galaxy, and from one galaxy to another when integrated over the full observed extent of each system. We examine direct comparisons of CC mode PAH ratios (7.7 micron)/(6.2 micron) and (8.6 micron)/(6.2 micron) to the mixed (CC/CH) mode PAH ratio (7.7 micron)/(11.3 micron). We find little variation in either mode, and no difference in trends between modes. While the local conditions change markedly over the observed regions of these galaxies, the properties of PAH emission show a remarkable degree of uniformity.
description: Astrophysical Journal, in press
„Mobilität“ – Ein multidisziplinärer Begriff im Alltagsverständnis
Creators: name: Hildebrandt, Nikolaus
name: Deubel, Katja
name: Dick, Michael
Publisher: name: TUHH Universitätsbibliothek
Year: 2001
Subjects: subject: 55.80:Verkehrswesen, Transportwesen: Allgemeines
subject: 55.81:Personenverkehr
subject: 74.75:Verkehrsplanung, Verkehrspolitik
subject: Mobilität
subject: Verkehrswissenschaft
subject: Verkehr
subject: Verkehrsforschung
subject: Verkehrsverhalten
subject: 55.80
subject: 55.81
subject: 74.75
subject: 380

description: In einer Strategie, die Verkehr als Folge orts- und raumbezogener Entscheidungen versteht, spielt die alltägliche Perspektive der Verkehrsteilnehmer eine wichtige Rolle. Diese werden im psychologischen Sinne als Handelnde verstanden: Die Teilhabe am Verkehr ist kein Entscheidungs- oder Einstellungsproblem, sondern eingebettet in persönliche Motive, Wünsche und Werte, und sie ist Teil eines individuellen Mobilitätsarrangements. Das von uns bearbeitete psychologische Arbeitspaket möchte diese komplexe Wirklichkeit für die Erforschung und Planung des Verkehrs zurückgewinnen sowie ökologischen Kriterien in dieser Alltagswirklichkeit zur Geltung verhelfen. Mit diesem Text wird der erste empirische Baustein dieses psychologischen Akzents dokumentiert. Mobilität als Rahmen für die Entstehung und das Verständnis von Verkehr ist subjektiv ein abstrakter Begriff. So stark er die Diskussion mittlerweile beherrscht, so unscharf ist seine Definition. Wir fragen danach, was Menschen unter Mobilität verstehen und mit welchen Alltagssituationen sie sie assoziieren.
Third order finite volume evolution Galerkin (FVEG) methods for two-dimensional wave equation system
Creators: name: Medviďová-Lukáčová, Mária
name: Warnecke, Gerald
name: Zahaykah, Yousef
Publisher: name: TUHH Universitätsbibliothek
Year: 2003
Subjects: subject: hyperbolic systems
subject: wave equation
subject: evolution Galerkin schemes
subject: recovery stage
subject: finite volume
subject: 510: Mathematik
subject: Hyperbolisches System
subject: Galerkin-Methode
subject: Evolutionsoperator
subject: Wellengleichung
subject: 510
subject: 65L05:Initial value problems
subject: 65M06:Finite difference methods
subject: 65M06
subject: 65L05

description: The subject of the paper is the derivation and analysis of third order finite volume evolution Galerkin schemes for the two-dimensional wave equation system. To achieve this the first order approximate evolution operator is considered. A recovery stage is carried out at each level to generate a piecewise polynomial approximation from the piecewise constants, to feed into the calculation of the fluxes. We estimate the truncation error and give numerical examples to demonstrate the higher order behaviour of the scheme for smooth solutions.
Stationary entanglement achievable by environment induced chain links
Creators: name: Memarzadeh, Laleh
name: Mancini, Stefano
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the possibility of chaining qubits by letting pairs of nearest neighbours qubits dissipating into common environments. We then study entanglement dynamics within the chain and show that steady state entanglement can be achieved.
Komplexitätsmanagement durch systemische Selbstskalierung
Creators: name: Paetow, Kai
name: Schmitt, Marco
Publisher: name: TUHH Universitätsbibliothek
Year: 2003
Subjects: subject: 004: Informatik
subject: 71.02:Theorie der Soziologie
subject: 54.72:Künstliche Intelligenz
subject: Skalierung
subject: Soziologische Theorie
subject: Mehragentensystem
subject: 71.02
subject: 54.72
subject: 300
subject: 004

description: Skalierbarkeit und Skalierung von Mulitagentensystemen sind in der Informatik Probleme von entscheidender Bedeutung. Die bisherige Debatte ist vor allem durch die Unbestimmtheit dieser beiden zentralen Begriffe erschwert. Daher wird in dieser Arbeit der Versuch unternommen, Skalierung aus soziologischer Sicht begrifflichkategorial klar zu definieren und theoretisch stärker zu reflektieren. Die hier geleistete begriffliche und konzeptionelle Arbeit orientiert sich an Niklas Luhmanns Theorie sozialer Systeme, der allgemeinen Komplexitätswissenschaft sowie an Ansätzen aus der Organisations- und Managementforschung. Skalierung wird als Operationalisierung von Komplexität verstanden. Durch die differenztheoretische Entfaltung des Skalierungsbegriffs wird ein heuristisches Instrumentarium gewonnen, das die Bezugspunkte des systemischen Komplexitätsmanagements deutlich benennt. Die hierbei eingenommene Perspektive auf MAS wird letztlich auf ein evolutionstheoretisches Fundament gestellt. Abschließend werden die Ergebnisse der Theoriearbeit in Form einiger Vorschläge zur Reorientierung der Skalierungsdebatte präsentiert.
description: In computer science, scalability and actual scaling processes of multiagent systems are problems of much concern. So far, the debate has been inhibited by the indeterminacy of both of these central terms. From a sociological point of view, it is tried to define the notions of scalability and scaling process more clearly and to reflect them in a profound theoretical context. The terminological and conceptual framework, developed here, is guided by Niklas Luhmann’s theory of social systems, general complexity science, and some approaches from organization and management research. Scaling processes are understood as operationalizations of complexity. By decomposing the term “scaling” difference-theoretically, a heuristic tool is achieved that clearly denotes the points of reference of complexity management. The perspective on MAS is built on an evolution-theoretical fundament. Finally, the results of this theoretically oriented paper are presented as proposals for a re-framing of the debate on scalability.
The exit velocity of a compressed air cannon
Creators: name: Rohrbach, Z. J.
name: Buresh, T. R.
name: Madsen, M. J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Popular Physics (physics.pop-ph)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: The use of compressed air cannons in an undergraduate lab provides a way to illustrate the cooperation of diverse physics concepts, such as conservation of momentum, the work-kinetic energy theorem, expansion of gas, air drag, and elementary Newtonian mechanics. However, recent proposals have disagreed as to whether the expansion of the gas in the cannon should be modeled as an adiabatic or an isothermal process. We built an air cannon that utilized a diaphragm valve to release our pressurized gas and found that neither model accurately predicted the exit velocity of our projectile. We present a new model, based on the flow of air through the valve, that is in much better agreement with our data.
Additional file 2 of Hospital management practices in county-level hospitals in rural China and international comparison
Creators: name: Hu, Min
name: Chen, Wen
name: Yip, Winnie
Publisher: name: figshare
Year: 2022
Subjects: subject: Medicine
subject: Environmental Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Additional file 2. Process scores in each dimension.
A variant of the inverted Lanczos method
Creators: name: Voß, Heinrich
Publisher: name: TUHH Universitätsbibliothek
Year: 2000
Subjects: subject: eigenvalue problem
subject: Lanczos method
subject: Toeplitz matrix
subject: symmetry properties
subject: 510: Mathematik
subject: Eigenwertproblem
subject: Toeplitz-Matrix
subject: 510
subject: 65F15:Eigenvalues, eigenvectors
subject: 65F15

description: In this note we study a variant of the inverted Lanczos method which computes eigenvalue approximates of a symmetric matrix A from the projection to a Krylov space of A method at least as long as reorthogonalization is not required. The method is applied to the problem of determining the smallest eigenvalue of a symmetric Toeplitz matrix. It is accelerated taking advantage of symmetry properties of the corresponding eigenvector.
Scattering induced current in a tight-binding band
Creators: name: Bruneau, Laurent
name: De Bievre, Stephan
name: Pillet, Claude-Alain
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In the single band tight-binding approximation, we consider the transport properties of an electron in a homogeneous static electric field. We show that repeated interactions of the electron with two-level systems in thermal equilibrium suppress the Bloch oscillations and induce a steady current, the statistical properties of which we study.
A Jacobi-Davidson-type Projection Method for nonlinear eigenvalue problems
Creators: name: Betcke, Timo
name: Voß, Heinrich
Publisher: name: TUHH Universitätsbibliothek
Year: 2002
Subjects: subject: nonlinear eigenvalue problem
subject: Jacobi-Davidson method
subject: projection method
subject: Rayleigh functional
subject: minmax characterization
subject: 510: Mathematik
subject: Projektionsverfahren
subject: Nichtlineares Eigenwertproblem
subject: 510
subject: 65F15:Eigenvalues, eigenvectors
subject: 65F15

description: This article discusses a projection method for nonlinear eigenvalue problems. The ansatz space is constructed by a Jacobi-Davidson type approach, and the arising eigenproblems of small dimension are solved by safeguarded inverse iteration. The method is applied to a rational eigenvalue problem governing the vibrations of tube bundle immersed in an inviscid compressible fluid.
Thermoelectric response in the incoherent transport region near Mott transition: the case study of La1-xSrxVO3
Creators: name: Uchida, M.
name: Oishi, K.
name: Matsuo, M.
name: Koshibae, W.
name: Onose, Y.
name: Mori, M.
name: Fujioka, J.
name: Miyasaka, S.
name: Maekawa, S.
name: Tokura, Y.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report a systematic investigation on the high-temperature thermoelectric response in a typical filling-control Mott transition system La1-xSrxVO3. In the vicinity of the Mott transition, incoherent charge transport appears with increasing temperature and the thermopower undergoes two essential crossovers, asymptotically approaching the limit values expected from the entropy consideration, as known as Heikes formula. By comparison with the results of the dynamical mean field theory, we show that the thermopower in the Mott critical state mainly measures the entropy per charge carrier that depends on electronic degrees of freedom available at the measurement temperature. Our findings verify that the Heikes formula is indeed applicable to the real correlated electron systems at practical temperatures (T>200K).
description: 6 pages, 6 figures. Accepted in Physical Review B
Additional file 1 of Hospital management practices in county-level hospitals in rural China and international comparison
Creators: name: Hu, Min
name: Chen, Wen
name: Yip, Winnie
Publisher: name: figshare
Year: 2022
Subjects: subject: Medicine
subject: Environmental Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Additional file 1. Selection of county-level administrative divisions in Guizhou.
On the boundary conditions for EG-methods applied to the two-dimensional wave equation system
Creators: name: Medviďová-Lukáčová, Mária
name: Warnecke, Gerald
name: Zahaykah, Yousef
Publisher: name: TUHH Universitätsbibliothek
Year: 2003
Subjects: subject: hyperbolic systems
subject: wave equation
subject: evolution Galerkin schemes
subject: absorbing boundary conditions
subject: reflecting boundary conditions
subject: 510: Mathematik
subject: Hyperbolisches System
subject: Galerkin-Methode
subject: Wellengleichung
subject: Randbedingung
subject: 510
subject: 65M06:Finite difference methods
subject: 35L05:Wave equation
subject: 65M06
subject: 35L05

description: The subject of the paper is the study of some nonreflecting and reflecting boundary conditions for the evolution Galerkin methods (EG) which are applied for the two-dimensional wave equation system. Different known tools are used to achieve this aim. Namely, the method of characteristics, the method of extrapolation, the Laplace transformation method, and the perfectly matched layer (PML) method. We show that the absorbing boundary conditions which are based on the use of the Laplace transformation lead to the Engquist-Majda first and second order absorbing boundary conditions. Further, following Berenger we consider the PML method. We discretize the wave equation system with the leap-frog scheme inside the PML while the evolution Galerkin schemes are used inside the computational domain. Numerical tests demonstrate that this method produces much less unphysical reflected waves as well as the best results in comparison with other techniques studied in the paper.
Making Counter-Orbiting Tidal Debris: The Origin of the Milky Way Disc of Satellites
Creators: name: Pawlowski, M. S.
name: Kroupa, P.
name: de Boer, K. S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Using stellar-dynamical calculations it is shown for the first time that counter-orbiting material emerges naturally in tidal interactions of disc galaxies. Model particles on both pro- and retrograde orbits can be formed as tidal debris in single encounters with disc galaxies of 1-to-1 and 4-to-1 mass ratios. A total of 74 model calculations are performed for a range of different initial parameters. Interactions include fly-by and merger cases. The fraction of counter-orbiting material produced varies over a wide range (from a few up to 50 percent). All fly-by models show a similar two-phase behaviour, with retrograde material forming first. Properties of the prograde and retrograde populations are extracted to make an observational discrimination possible. During such encounters the tidal debris occupies a certain region in phase space. In this material, tidal-dwarf galaxies may form. The modelling therefore can explain why galaxies may have dwarf galaxies orbiting counter to the bulk of their dwarf galaxies. An example is the Sculptor dwarf of the Milky Way, which orbits counter to the bulk of the disc of satellites. The modelling thus supports the scenario of the MW satellites being ancient tidal-dwarf galaxies formed from gaseous material stripped from another galaxy during an encounter with the young MW. A possible candidate for this galaxy is identified as the Magellanic Cloud progenitor galaxy. Its angular motion fits the angular motion of the MW disc of satellites objects. This scenario is in agreement with Lynden-Bell's original suggestion for the origin of the dSph satellites and the near-unbound orbit of the LMC.
description: 26 pages, 13 figures. Accepted for publication in Astronomy and Astrophysics
Ionisation state of WHIM: Ionisation by galaxy cluster photons alters the ionisation state of the nearby warm-hot intergalactic medium
Creators: name: Štofanová, Lýdia
Publisher: name: Zenodo
Year: 2022
Subjects: X-ray Spectroscopy
Photoionization Modeling
Large-scale structure

description: The physical properties of the faint and extremely tenuous plasma in the far outskirts of galaxy clusters, the circumgalactic media of normal galaxies, and filaments of the cosmic web, remain one of the biggest unknowns in our story of large-scale structure evolution. Modeling the spectral features due to emission and absorption from this very diffuse plasma poses unique challenges, as both collisional and photo-ionisation processes must be accounted for. In this paper we study the ionisation by galaxy cluster photons in addition to the photo-ionisation by the cosmic UV/X-ray background and its impact on the ionisation balance. We model realistic spectra by taking into account the cosmic UV/X-ray background together with the emission from three different cool-core galaxy clusters: A262, A1795 and A2029, and illuminate the photo-ionised gas in the galaxy cluster vicinity. We assume the gas has temperatures between 0.001 - 1 keV (~10^4 - 10^7 K), densities between 10^-6 and 0.1 cm-3 and can be located between r_500 and ~13 Mpc from the cluster center. We find that depending on the distance from the galaxy cluster and the plasma properties, the total photo-ionisation rate can be higher than 10% or even 100% of the total ionization rate. We show how this affects the ionisation fractions of C IV, C V, CVI, N VII, O VI, O VII, O VIII, Ne VIII, Ne IX and Fe XVII ions and compare it with the ionization fractions with photo-ionization from cosmic background only as well as with plasma that is in collisional ionisation equilibrium.