cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Scalar-Tensor theories within Asymptotic Safety
Creators: name: Laporte, Cristobal
name: Pereira, Antonio D.
name: Saueressig, Frank
name: Wang, Jian
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Asymptotic Safety provides an elegant mechanism for obtaining a consistent high-energy completion of gravity and gravity-matter systems. Following the initial idea by Steven Weinberg, the construction builds on an interacting fixed point of the theories renormalization group (RG) flow. In this work we use the Wetterich equation for the effective average action to investigate the RG flow of gravity supplemented by a real scalar field. We give a non-perturbative proof that the subspace of interactions respecting the global shift-symmetry of the scalar kinetic term is closed under RG transformations. Subsequently, we compute the beta functions in an approximation comprising the EinsteinHilbert action supplemented by the shift-symmetric quartic scalar self-interaction and the two lowest order shift-symmetric interactions coupling scalar-bilinears to the spacetime curvature. The computation utilizes the background field method with an arbitrary background, demonstrating that the results are manifestly background independent. Our beta functions exhibit an interacting fixed point suitable for Asymptotic Safety, where all matter interactions are non-vanishing. The presence of this fixed point is rooted in the interplay of the matter couplings which our work tracks for the first time. The relation of our findings with previous results in the literature is discussed in detail and we conclude with a brief outlook on potential phenomenological applications.
description: 51 pages, 5 figures
Charge Transport in Disordered Graphene-Based Low Dimensional Materials
Creators: name: Cresti, Alessandro
name: Nemec, Norbert
name: Biel, Blanca
name: Niebler, Gabriel
name: Triozon, Francois
name: Cuniberti, Gianaurelio
name: Roche, Stephan
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Two-dimensional graphene, carbon nanotubes and graphene nanoribbons represent a novel class of low dimensional materials that could serve as building blocks for future carbon-based nanoelectronics. Although these systems share a similar underlying electronic structure, whose exact details depend on confinement effects, crucial differences emerge when disorder comes into play. In this short review, we consider the transport properties of these materials, with particular emphasis to the case of graphene nanoribbons. After summarizing the electronic and transport properties of defect-free systems, we focus on the effects of a model disorder potential (Anderson-type), and illustrate how transport properties are sensitive to the underlying symmetry. We provide analytical expressions for the elastic mean free path of carbon nanotubes and graphene nanoribbons, and discuss the onset of weak and strong localization regimes, which are genuinely dependent on the transport dimensionality. We also consider the effects of edge disorder and roughness for graphene nanoribbons in relation to their armchair or zigzag orientation.
description: 32 pages, 19 figures, to appear in Nano Research
Vancouver’s residential design guideline process : a case study
Creators: name: Bernstein, Richard Charles
Publisher: name: University of British Columbia
Year: 2010

description: This study examines the application of design guidelines within the City of Vancouver's Development Permit Approval process. The guidelines are a phenomenon of the '70's, having emerged because of a failure of many projects to meet various user needs and expectations concerning residential lifestyle, particularly in higher density projects. The Planning Department of the City of Vancouver has embraced the use of design guidelines as a means to provide architects and developers with direction and encouragement for producing designs which will meet user needs and make positive contributions to surrounding neighbourhoods. It was hypothesized that although the majority of design guidelines are intended to be generative, their use for evaluative purposes in terms of the planning departments review of projects has created an impression amongst members of the above mentioned professions that the guidelines are being applied in a regulatory manner. It was further hypothesized that the current discretionary zoning system may in practice be as inflexible as the highly regulatory traditional zoning system it was intended to replace. The hypotheses were tested through a case study of the use of design guidelines in Vancouver's Development Approval process. A verbal and graphic comparative analysis between traditional and discretionary zoning systems was made. In addition these two development control procedures were examined in relation to the relevant literature concerning administrative discretionary authority. The hypotheses were further tested through personal interviews with several architects in private practice and members of the City of Vancouver's Planning Department. The study revealed that by and large, the majority of architects did not feel that the design guidelines were used in a regulatory manner. In this sense the hypothesis was disproved. Nevertheless, it is essential to note that several architects pointed to isolated cases whereby the guidelines were applied in a regulatory fashion. The problem; lay not so much with the guidelines themselves, but rather with their application by what was perceived as incompetent, inflexible administrators. In this regard the first hypothesis was given minor support. The second hypothesis was disproved through all of the research methods mentioned above. Again, however, isolated examples of inflexible attitudes on the part of poorly trained administrators were cited by some architects as being detrimental to the flexibility of the discretionary zoning system. The study showed that the continued use of both design guidelines and the discretionary zoning system was supported by the representative sampling of architects and planners.
Molybdenum and Methods of Application in Relation to Growth and Yield of Cabbage (Brassica Oleacea Var Capitata L.)
Creators: name: Hasan, Md. Mahfuzul
Publisher: name: figshare
Year: 2025
Subjects: classificationCode: 300204
subject: Agricultural management of nutrients
classificationCode: 300205
subject: Agricultural production systems simulation
classificationCode: 300411
subject: Fertilisers (incl. application)

description: Molybdenum benefits plants by acting as a crucial micronutrient that aids in enzyme activation, nitrogen fixation, improving synthesis of proteins and amino acids, promoting healthy growth, improving nutrient uptake, and enhancing crop yield. The goals of this investigation are to evaluate the effect of molybdenum and methods of application on the growth, yield, and yield attributes of cabbage (Brassica oleacea var. capitata L.). This study was performed following a randomized complete block design (RCBD) with 3 replications and four distinct molybdenum dosages, viz., i) control ii) 1 kg/ha. iii) 2 kg/ha iv) 3 kg/ha and three methods of application, viz., i) 100% basal application, ii) 50% basal + 50% foliar spray, iii) 100% foliar spray were utilized in this investigation. 3 kg/ha molybdenum contributes to maximal plant height (37.73 cm), number of leaves (21.64), leaf length (38.56 cm), and breadth (32.03 cm). The highest plant height (36.53 cm), fresh weight of roots (50.65 g), head diameter (19.61 cm), and gross head weight (2.11 kg) were obtained from 100% foliar spray, but gross yield (78.54 t/ha), marketable head weight (1.08 kg), and marketable yield (54.19 t/ha) were found from the 100% basal application. The combined effect of molybdenum and methods of application has a significant influence on head diameter (21.93 cm), gross head weight (2.27 kg), gross yield (113.50 t/ha), marketable head weight (1.57 kg), and marketable yield (78.50 t/ha) for 3 kg/ha molybdenum and 100% foliar spray. The plant growth, yield, and yield-attributing characteristics of cabbage were ignificantly influenced by the combination of 3 kg/ha molybdenum and 100% foliar spray treatment.
COVID-19 Working Paper: COVID-19 and the U.S. Meat and Poultry Supply Chains
Creators: name: Vaiknoras, Kate
name: Hahn, William
name: Padilla, Samantha
name: Valcu-Lisman, Adriana
name: Grossen, Grace
name: Vaiknoras, Kate
name: Hahn, William
name: Padilla, Samantha
name: Valcu-Lisman, Adriana
name: Grossen, Grace
Publisher: name: Unknown
Year: 2022
Subjects: subject: Industrial Organization
subject: COVID-19
subject: pandemic
subject: coronavirus
subject: meat processing

description: This working paper outlines the impacts of COVID-19 on U.S. meat and poultry supply chains in 2020, describing how the industry reacted to the onset of the COVID-19 pandemic and adapted during the ongoing crisis.
Tracing the dynamical interplay of low-energy reaction processes of exotic nuclei using a two-center molecular continuum
Creators: name: Moschini, Laura
name: Diaz-Torres, Alexis
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The competition among reaction processes of a weakly-bound projectile at intermediate times of a slow collision has been unraveled. This has been done using a two-center molecular continuum within a semiclassical, time-dependent coupled-channel reaction model. Dynamical probabilities of elastic scattering, transfer and breakup agree with those derived from the direct integration of the time-dependent Schrödinger equation, demonstrating the usefulness of a two-center molecular continuum for gaining insights into the reaction dynamics of exotic nuclei.
Dieter Baacke Preis – Handbuch 4, Kinder im Blick. Medienkompetenz statt Medienabstinenz
Creators: name: Augustin, Elisabeth
Publisher: name: Medienimpulse
Year: 2010

description: Verlag: GMK Erscheinungsjahr: 2009
description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
Welcome home
Creators: name: Krucsay, Susanne
Publisher: name: Medienimpulse
Year: 2010

description: Produktion: Wega Film Vertrieb: Poly film video Länge: 98 Min.
description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
Metzler Lexikon Literatur- und Kulturtheorie
Creators: name: Krucsay, Susanne
Publisher: name: Medienimpulse
Year: 2010

description: Verlag: J.B. Metzler Erscheinungsort: Stuttgart – Weimar Erscheinungsjahr: 2008
description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
Mein Mörder
Creators: name: Krucsay, Susanne
Publisher: name: Medienimpulse
Year: 2010

description: Produktion Wega Film Vertrieb: Poly film video Länge: 88 Min.
description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
Meine liebe Republik
Creators: name: Krucsay, Susanne
Publisher: name: Medienimpulse
Year: 2010

description: Produktion Wega Film Vertrieb: Poly film video Länge: 80 Min.
description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
Classifying near-threshold enhancement using deep neural network
Creators: name: Sombillo, Denny Lane B.
name: Ikeda, Yoichi
name: Sato, Toru
name: Hosaka, Atsushi
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: One of the main issues in hadron spectroscopy is to identify the origin of threshold or near-threshold enhancement. Prior to our study, there is no straightforward way of distinguishing even the lowest channel threshold-enhancement of the nucleon-nucleon system using only the cross-sections. The difficulty lies in the proximity of either a bound or virtual state pole to the threshold which creates an almost identical structure in the scattering region. Identifying the nature of the pole causing the enhancement falls under the general classification problem and supervised machine learning using a feed-forward neural network is known to excel in this task. In this study, we discuss the basic idea behind deep neural network and how it can be used to identify the nature of the pole causing the enhancement. The applicability of the trained network can be explored by using an exact separable potential model to generate a validation dataset. We find that within some acceptable range of the cut-off parameter, the neural network gives high accuracy of inference. The result also reveals the important role played by the background singularities in the training dataset. Finally, we apply the method to nucleon-nucleon scattering data and show that the network was able to give the correct nature of pole, i.e. virtual pole for ${}^1S_0$ partial cross-section and bound state pole for ${}^3S_0$.
description: 10 pages, 4 figures, Contribution to the Proceedings for 8th Asia-Pacific Conference on Few-Body Problems in Physics (APFB2020), March 1-5 2021, Kanazawa, Japan
Dynamics and Observational Signatures of Shell-like Black Hole Mimickers
Creators: name: Danielsson, Ulf
name: Lehner, Luis
name: Pretorius, Frans
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We undertake the task of studying the non-linear dynamics of quantum gravity motivated alternatives to black holes that in the classical limit appear as ultra-compact shells of matter. We develop a formalism that should be amenable to numerical solution in generic situations. For a concrete model we focus on the spherically symmetric AdS black bubble -- a shell of matter at the Buchdahl radius separating a Schwarzschild exterior from an AdS interior. We construct a numerical code to study the radial dynamics of and accretion onto AdS black bubbles, with exterior matter provided by scalar fields. In doing so we develop numerical methods that could be extended to future studies beyond spherical symmetry. Regarding AdS black bubbles in particular, we find that the original prescription for the internal matter fluxes needed to stabilize the black bubble is inadequate in dynamical settings, and we propose a two parameter generalization of the flux model to fix this. To allow for more efficient surveys of parameter space, we develop a simpler numerical model adapted to spherically symmetric bubble dynamics. We identify regions of parameter space that do allow for stable black bubbles, and moreover allow control to a desired end-state after an accretion episode. Based on these results, and evolution of scalar fields on black bubble backgrounds, we speculate on some observational consequences if what are currently presumed to be black holes in the universe were actually black bubbles.
description: 27 pages, 7 figures
Lies es zwischen den Pixeln
Creators: name: Longerich, Tim
Publisher: name: Medienimpulse
Year: 2010

description: Sind Computerspiele ‚Text’? Um diese Frage zu beantworten, entwickelt der vorliegende Beitrag zunächst eine Text-Definition, die dem Medium ‚Computerspiel’ gerecht wird. Auf dieser Basis werden die Kriterien prototypischer Textualität diskutiert und Überschneidungen der Merkmale beim klassischen Text und bei den Spielelementen von Computerspielen aufgezeigt. Ausblickend auf die Konsequenzen eines Transfers des Textbegriffes werden daneben die Konzepte ‚Intertextualität’ sowie ‚Isotopie’ an Computerspielen beleuchtet.
description: Medienimpulse, Bd. 47 Nr. 2 (2009): 2/2009 - Computerspiele
Big data, complex networks and markets
Creators: name: Pennacchioli, Diego
Publisher: name: IMT Alti Studi Lucca
Year: 2014
Subjects: QA75 Electronic computers. Computer science

description: This thesis is focused on the study of new techniques of analysis coming from diverse fields (Complex Networks Analysis, Data Mining, and Big Data).
Main aim is to better understand systems characterized by a high level of complexity. Markets are the chosen application scenario. In these complex systems,
to find the right balance between the forces of demand and supply is very challenging, especially considering that they are characterized by imperfect but massive
and fast information. In this context, the thesis presents approaches to face several open questions: how to find the general pattern of shopping behavior, how to mine
the product space to find the best product/service that meets the demand, what is the role of the social influence between customers, and so on. The methods and techniques,
belonging to the field of Complex Networks Analysis, are complementary to the usual ones of Data Mining. While in Data Mining the purpose is to search patterns
and special distributions in a large dataset, here the purpose is to give a focus to the relations between entities of the markets, looking more to the whole system
than to the single behavior. The thesis, finally, presents results of experiments performed on real world high quality datasets, providing, in addition to the theoretic
results, practical application scenarios.
CP-violating Higgs boson mixing in chargino production at the muon collider
Creators: name: Kittel, Olaf
name: von der Pahlen, Federico
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the pair-production of charginos in the CP-violating Minimal Supersymmetric Standard Model at center-of-mass energies around the heavy neutral Higgs boson resonances. If these resonances are nearly degenerate, as it can happen in the Higgs decoupling limit, radiatively induced scalar-pseudoscalar transitions can be strongly enhanced. The resulting mixing in the Higgs sector leads to large CP-violating effects, and a change of their mass spectrum. For longitudinally polarized muon beams, we analyze CP asymmetries which are sensitive to the interference of the two heavy neutral Higgs bosons. We present a detailed numerical analysis of the cross sections, chargino branching ratios, and the CP observables. We obtain sizable CP-asymmetries, which would be accessible in future measurements at a muon collider. Especially for intermediate values of the parameter \tanβ, where the largest branching ratios of Higgs bosons into charginos are expected, this process allows to analyze the Higgs sector properties and its interaction to supersymmetric fermions.
description: 40 pages, 10 figures. Comments added. Version to appear in JHEP
Schriftspracherwerb am Computer
Creators: name: Mulley, Ursula
Publisher: name: Medienimpulse
Year: 2010

description: Der Einsatz von Computern gewinnt im Kontext des zukunftsorientierten und individuellen Unterrichts unserer Informationsgesellschaft an großer Bedeutung und das Arbeiten mit diesem Werkzeug wird als vierte Kulturtechnik, neben dem Lesen, Schreiben und Rechnen, im Lehrplan fixiert. Jedes zweite Kind nutzt Lernprogramme vor allem zuhause und mehr als die Hälfte der SchülerInnen hat einen Internetzugang. Die technische Ausrüstung der Schulen hat sich zwar in den letzten Jahren verbessert, der Einsatz bleibt jedoch weit hinter den pädagogisch sinnvollen Möglichkeiten. Die didaktische und pädagogische Forschung in der Volksschule zum Computereinsatz ist defizitär. Grundschulpädagogik steht im starken Gegensatz zur inzwischen erreichten häuslichen Bedeutung des längst nicht mehr neuen elektronischen Medieneinsatzes. Das an der GEPS-Volksschule Brünner Straße, 1210 Wien durchgeführte Projekt möchte einen Beitrag leisten diese Wichtigkeit zu unterstreichen, indem es einen Bereich aufzeigt, wo Computereinsatz effizient individuelle und differenzierte Möglichkeiten für Kinder mit Teilleistungsstörungen bietet, um in den Unterricht integriert zu werden.
description: Medienimpulse, Bd. 47 Nr. 2 (2009): 2/2009 - Computerspiele
Spectral variability of ultraluminous X-ray sources
Creators: name: Kajava, Jari J. E.
name: Poutanen, Juri
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study spectral variability of 11 ultraluminous X-ray sources (ULX) using archived XMM-Newton and Chandra observations. We use three models to describe the observed spectra; a power-law, a multi-colour disk (MCD) and a combination of these two models. We find that out of the 11 ULXs in our sample, 7 ULXs show a correlation between the luminosity and the photon index Gamma (hereafter L-Gamma correlation). Furthermore, out of the 7 ULXs that have the L-Gamma correlation, 4 ULXs also show spectral pivoting in the observed energy band. We also find that two ULXs show an L-Gamma anti-correlation. The spectra of 4 ULXs in the sample can be adequately fitted with a MCD model. We compare these sources to known black hole binaries (BHB) and find that they follow similar paths in their luminosity-temperature (hereafter L-T) diagrams. Finally we show that the 'soft excess' reported for many of these ULXs at 0.2 keV seem to follow a trend L \propto T^{-4} when modeled with a power-law plus a 'cool' MCD model. This is contrary to the expected L \propto T^4 relation that is expected from theory and what is seen for many accreting BHBs.
description: 9 pages, 3 figures; to appear in the proceedings of "Cool discs, hot flows: The Varying Faces of Accreting Compact Objects", Funasdalen, Sweden, 2008, ed. M. Axelsson (New York: AIP)
Internet in der Schule, Schule im Internet
Creators: name: Maireder, Axel
name: Nagl, Manuel
Publisher: name: Medienimpulse
Year: 2009

description: Fragen nach der Bedeutung des Internet für schulische Lehr- und Lernprozesse und der Bedeutung der Schule für das Internetnutzungsverhalten Jugendlicher standen im Zentrum dieses explorativen Forschungsprojektes, das 2008/2009 an zehn österreichischen Schulen durchgeführt wurde. In der Analyse von Gruppendiskussionen von Lehrerinnen und Lehrern sowie Schülerinnen und Schülern zeigen sich dabei folgende zentrale Problemfelder: unterschiedliche Quellenevaluationskonzepte von Jugendlichen und ihren Lehrkräften führen zu Missverständnissen; fehlendes Feedback auf schulische Arbeiten lässt die Sorgfalt bei der schulischen Informationsarbeit schwinden; in Social Media bilden sich schulische Support- als auch Inhibitionsnetzwerke heraus; sowie Lehrerinnen und Lehrer werden vielfach von einer impliziten Internetangst vor der Implementierung des Internet in den Unterricht abgehalten. Das Projekt wurde vom Bundesministerium für Unterricht, Kunst und Kultur finanziert und von Univ. Prof. Dr. Thomas A. Bauer geleitet.
description: Medienimpulse, Bd. 47 Nr. 2 (2009): 2/2009 - Computerspiele
Die Relation von Medienkultur und sozialer Schicht.
Creators: name: Mutsch, Ursula
name: Jones, Sigrid
name: Swertz, Christian
Publisher: name: Medienimpulse
Year: 2012

description: In der vorliegenden Studie wird die Medienkultur von Volksschülerinnen und -schülern, deren Eltern und deren Lehrerinnen und Lehrern mittels einer quantitativen Fragebogenerhebung in Wien verglichen. Die Erhebung wurde im Rahmen eines Forschungsprojekts der Wiener Medienpädagogik (Universität Wien) durchgeführt. Ausgangspunkt der Studie sind die Annahmen, dass Medienkultur (1) von geografischen und historischen Determinanten bestimmt und im soziokulturellen Kontext zu betrachten ist und (2) Auswirkungen auf die erfolgreiche Integration von Medienbildung und Media Literacy in Volksschulen hat. Zunächst werden der Kontext der Studie und allgemeine Überlegungen vorgestellt. Dem folgt eine Beschreibung der methodischen Umsetzung der Studie mit anschließender Präsentation und Diskussion ausgewählter Resultate. Die Ergebnisse weisen auf schichtspezifische Unterschiede der Medienkultur zwischen Schülerinnen bzw. Schülern und Lehrkräften hin.
description: Medienimpulse, Bd. 47 Nr. 2 (2009): 2/2009 - Computerspiele
Bridging the Gap between Private Data and AI: A Beginner's Guide to Retrieval Augmented Generation (RAG)
Creators: name: Niesel, Fritz
name: Schmidt, Mascha Samantha
name: Haguet, Victor
Publisher: name: Zenodo
Year: 2025

description: In April 2025, Fritz Niesel, Mascha Schmidt and Victor Haguet presented about RAG and their work. The presentation recording is available on YouTube https://www.youtube.com/watch?v=L-3ypGheljs&t=2136s 

Abstract: AI is transforming administrative and scientific workflows by automating tedious cognitive tasks. However, one of our most valuable resources - private and sensitive documents - often remains inaccessible to AI solutions. Retrieval Augmented Generation (RAG) offers a way to bridge this gap. It enables AI models to efficiently process and search large private data sources while maintaining control over data access and security.

In this talk, we’ll guide you through the process of building a RAG system, from understanding its core components to integrating it into real-world applications. We’ll begin by introducing RAG and demonstrating how it enhances knowledge retrieval where standard LLMs fall short. Then, we’ll break down key concepts such as chunking, embedding, vector storage and retrieval. Finally, we’ll explore how to tailor RAG for advanced use cases and integrate it into data-driven applications.

Whether you’re a developer, researcher, or AI enthusiast, this session will provide a clear roadmap for using RAG effectively. Join us to learn when to use RAG, what to expect, and how to take your LLM applications to the next level.

Link to the notebook: https://codebase.helmholtz.cloud/sdlaml-public-ressources/RAG_tutorial_langchain_blablador/
Relation of cyclotron resonant energy and luminosity in a strongly magnetized neutron star GRO J1008-57 observed by Insight-HXMT
Creators: name: Chen, X.
name: Wang, W.
name: Tang, Y. M.
name: Ding, Y. Z.
name: Tuo, Y. L.
name: Mushtukov, A. A.
name: Nishimura, O.
name: Zhang, S. N.
name: Ge, M. Y.
name: Song, L. M.
name: Lu, F. J.
name: Zhang, S.
name: Qu, J. L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Cyclotron line scattering features are detected in a few tens of X-ray pulsars (XRPs) and used as direct indicators of a strong magnetic field at the surface of accreting neutron stars (NSs). In a few cases, cyclotron lines are known to be variable with accretion luminosity of XRPs. It is accepted that the observed variations of cyclotron line scattering features are related to variations of geometry and dynamics of accretion flow above the magnetic poles of a NS. A positive correlation between the line centroid energy and luminosity is typical for sub-critical XRPs, where the accretion results in hot spots at the magnetic poles. The negative correlation was proposed to be a specific feature of bright super-critical XRPs, where radiation pressure supports accretion columns above the stellar surface. Cyclotron line in spectra of Be-transient X-ray pulsar GRO J1008-57 is detected at energies from $\sim 75 -90$ keV, the highest observed energy of cyclotron line feature in XRPs. We report the peculiar relation of cyclotron line centroid energies with luminosity in GRO J1008-57 during the Type II outburst in August 2017 observed by Insight-HXMT. The cyclotron line energy was detected to be negatively correlated with the luminosity at $3.2\times 10^{37}\,\ergs
description: 9 pages. 5 figures, 2 tables, accept for publication in ApJ
Numerical simulations of continuum-driven winds of super-Eddington stars
Creators: name: van Marle, A. J.
name: Owocki, S. P.
name: Shaviv, N. J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results of numerical simulations of continuum-driven winds of stars that exceed the Eddington limit and compare these against predictions from earlier analytical solutions. Our models are based on the assumption that the stellar atmosphere consists of clumped matter, where the individual clumps have a much larger optical thickness than the matter between the clumps. This `porosity' of the stellar atmosphere reduces the coupling between radiation and matter, since photons tend to escape through the more tenuous gas between the clumps. This allows a star that formally exceeds the Eddington limit to remain stable, yet produce a steady outflow from the region where the clumps become optically thin. We have made a parameter study of wind models for a variety of input conditions in order to explore the properties of continuum-driven winds. The results show that the numerical simulations reproduce quite closely the analytical scalings. The mass loss rates produced in our models are much larger than can be achieved by line driving. This makes continuum driving a good mechanism to explain the large mass loss and flow speeds of giant outbursts, as observed in eta Carinae and other luminous blue variable (LBV) stars. Continuum driving may also be important in population III stars, since line driving becomes ineffective at low metalicities. We also explore the effect of photon tiring and the limits it places on the wind parameters.
description: Accepted for publication by MNRAS
The first heavy-metal hot subdwarf composite binary SB 744
Creators: name: Németh, Péter
name: Vos, Joris
name: Molina, Francisco
name: Bastian, Alexander
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: A radial velocity follow-up of the long-period sdOB+G1V type spectroscopic binary SB 744 revealed strong lines of fluorine and lead in the optical spectrum of the sdOB star and subsolar metallicity in the G1V companion. With high-quality observations and Gaia astrometric data, we aim at measuring the chemical composition and Galactic kinematics of the system to put it in context with known populations of hot subdwarfs. Such binary systems have high potential, as they give insights into the late stages of binary evolution as well as into the mysterious formation of stripped core helium-burning stars. We have analyzed the optical spectra with homogeneous atmospheric models to derive surface parameters of the binary members from a direct wavelength space decomposition and independently measured the atmospheric properties of the cool companion. The two independent methods reached consistent results, which, amended with constraints from spectral energy distributions provided a subdwarf mass. The Gaia astrometry allowed us to derive the Galactic kinematics of the system. SB 744 turned out to be an old, Population II system, that has gone through dramatic events. The hot subdwarf star belongs to the heavy-metal subclass of sdOB stars and we report super-solar abundances of lead, based on Pb III/IV lines. The He abundance of the hot subdwarf is the lowest among the known heavy-metal sdOB stars. The presence of fluorine implies that SB 744 was once a hierarchical triple system and the inner binary has merged in the near past. As an alternative scenario, single-star evolution through late core helium flash and atmospheric mixing can also produce the observed fluorine abundances. The atmospheric metal over-abundances currently observed are perhaps the results of a combination of mixing processes during formation and radiative support.
description: Accepted for publication in Astronomy and Astrophysics
Local HI Absorption towards the Magellanic Cloud foreground using ASKAP
Creators: name: Nguyen, Hiep
name: McClure-Griffiths, N. M.
name: Dempsey, James
name: Dickey, John M.
name: Lee, Min-Young
name: Lynn, Callum
name: Murray, Claire E.
name: Stanimirović, Snežana
name: Busch, Michael P.
name: Clark, Susan E.
name: Dawson, J. R.
name: Dénes, Helga
name: Gibson, Steven
name: Jameson, Katherine
name: Joncas, Gilles
name: Kemp, Ian
name: Leahy, Denis
name: Ma, Yik Ki
name: Marchal, Antoine
name: Miville-Deschênes, Marc-Antoine
name: Pingel, Nickolas M.
name: Seta, Amit
name: Soler, Juan D.
name: van Loon, Jacco Th.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the largest Galactic neutral hydrogen HI absorption survey to date, utilizing the Australian SKA Pathfinder Telescope at an unprecedented spatial resolution of 30''. This survey, GASKAP-HI, unbiasedly targets 2,714 continuum background sources over 250 square degrees in the direction of the Magellanic Clouds, a significant increase compared to a total of 373 sources observed by previous Galactic absorption surveys across the entire Milky Way. We aim to investigate the physical properties of cold (CNM) and warm (WNM) neutral atomic gas in the Milky Way foreground, characterized by two prominent filaments at high Galactic latitudes (between $-45^{\circ}$ and $-25^{\circ}$). We detected strong HI absorption along 462 lines of sight above the 3$σ$ threshold, achieving an absorption detection rate of 17%. GASKAP-HI's unprecedented angular resolution allows for simultaneous absorption and emission measurements to sample almost the same gas clouds along a line of sight. A joint Gaussian decomposition is then applied to absorption-emission spectra to provide direct estimates of HI optical depths, temperatures, and column densities for the CNM and WNM components. The thermal properties of CNM components are consistent with those previously observed along a wide range of Solar neighborhood environments, indicating that cold HI properties are widely prevalent throughout the local interstellar medium. Across our region of interest, CNM accounts for ~30% of the total HI gas, with the CNM fraction increasing with column density toward the two filaments. Our analysis reveals an anti-correlation between CNM temperature and its optical depth, which implies that CNM with lower optical depth leads to a higher temperature.
description: Largest Galactic HI Absorption Survey To Date (GASKAP-HI): Cold Atomic Gas in the Magellanic Cloud foreground using Australian SKA Pathfinder. This paper has 19 pages, 17 figures. This paper has been accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journal
Extrasolar planets and brown dwarfs around A-F type stars VI. High precision RV survey of early type dwarfs with HARPS
Creators: name: Lagrange, A. -M.
name: Desort, M.
name: Galland, F.
name: Udry, S.
name: Mayor, M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: (Abridged) Aims: Systematic surveys to search for exoplanets have been mostly dedicated to solar-type stars sofar. We developed in 2004 a method to extend such searches to earlier A-F type dwarfs and started spectroscopic surveys to search for planets and quantify the detection limit achievable when taking into account the stars properties and their actual levels of intrinsic variations. We give here the first results of our southern survey with HARPS. Results: 1) 64% of the 170 stars with enough data points are found to be variable. 20 are found to be binaries or candidate binaries (with stars or brown dwarfs). More than 80% or the latest type stars (once binaries are removed) are intrinsically variable at a 2 m/s precision level. Stars with earlier spectral type (B-V <= 0.2) are either variable or associated to levels of uncertainties comparable to the RV rms observed on variable stars of same B-V. 2) We have detected one long-period planetary system around an F6IV-V star. 3) We have quantified the jitter due to stellar activity and we show that taking into account this jitter in addition to the stellar parameters, it is still possible to detect planets with HARPS with periods of 3 days (resp. 10 days and 100 days) on 91% (resp. 83%, 61%) of them. We show that even the earliest spectral type stars are accessible to this type of search, provided they have a low vsini and low levels of activity. 4) Taking into account the present data, we compute the actually achieved detection limits for 107 targets and discuss the limits as a function of B-V. Given the data at hand, our survey is sensitive to short-period (few days) planets and to longer ones (100 days) at a lower extent (latest type stars). We derive first constrains on the presence of planets around A-F stars for these ranges of periods.
description: 18 pages, 12 figures, 5 tables, A&A accepted
title: Front Matter, Table of Contents, Preface, Conference Organization
Creators: name: Coudert, David
name: Natale, Emanuele
Publisher: name: Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Year: 2021
Subjects: subject: Front Matter
subject: Table of Contents
subject: Preface
subject: Conference Organization
subject: Theory of computation → Design and analysis of algorithms

description: Front Matter, Table of Contents, Preface, Conference Organization
description: LIPIcs, Vol. 190, 19th International Symposium on Experimental Algorithms (SEA 2021), pages 0:i-0:xii
Star formation histories of early-type galaxies at z = 1.2 in cluster and field environments
Creators: name: Gobat, R.
name: Rosati, P.
name: Strazzullo, V.
name: Rettura, A.
name: Demarco, R.
name: Nonino, M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We derive the star formation histories of early-type galaxies at z = 1.2 in both low and high density environments. To this purpose, we compare the co-added spectroscopic and 8-9 band photometric data of 43 mass selected early-type galaxies in the massive cluster RDCS J1252.9-2927 and the GOODS/CDF-S field with a large grid of composite stellar population models. We find that the cluster early-type galaxies formed the bulk of their stars approximately 0.5 Gyr earlier than early-types in the field, whereas field early-types presumably finish forming their stellar content on a longer time scale. Such a difference is particularly evident at lower masses but becomes negligible for the most massive galaxies. While our differential analysis of the stellar population parameters of cluster and field galaxies in the same mass range convincingly shows distinct star formation histories, the absolute age difference remains model dependent. Using the star formation histories that best fit the SEDs of the red sequence galaxies in RDCS 1252.9-2927, we reconstruct the evolution of the cluster red sequence and find that it was established over 1 Gyr and is expected to dissolve by z ~ 2.
description: 10 pages, 11 figures, accepted for publication in A&A, references added, minor corrections
COVID-19 Working Paper: U.S.-Mexico Agricultural Trade in 2020
Creators: name: Zahniser, Steven
name: Zahniser, Steven
Publisher: name: Unknown
Year: 2022
Subjects: subject: International Relations/Trade
subject: COVID-19
subject: coronavirus
subject: Mexico
subject: United States

description: This paper uses detailed trade statistics to explore how and why U.S.-Mexico agricultural trade changed during 2020, the first year of the COVID-19 pandemic.
Introducing a Hybrid Method of Radiative Transfer in Smoothed Particle Hydrodynamics
Creators: name: Forgan, Duncan
name: Rice, Ken
name: Stamatellos, Dimitris
name: Whitworth, Anthony
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a new method of incorporating radiative transfer into Smoothed Particle Hydrodynamics (SPH). There have been many recent attempts at radiative transfer in SPH (Stamatellos et al 2005, 2005, Mayer et al 2007, Whitehouse and Bate 2006), however these are becoming increasingly complex, with some methods requiring the photosphere to be mapped (which is often of non-trivial geometric shape), and extra conditions to be applied there (matching atmospheres as in Cai et al (2008), or specifying cooling at the photosphere as in Mayer et al (2007)). The method of identifying the photosphere is usually a significant addition to the total simulation runtime, and often requires extra free parameters, the changing of which will affect the final results. Our method is not affected by such concerns, as the photosphere is constructed implicitly by the algorithm without the need for extra free parameters. The algorithm used is a synergy of two current formalisms for radiative effects: a) the polytropic cooling formalism proposed by Stamatellos et al (2007), and b) flux-limited diffusion, used by many authors to simulate radiation transport in the optically thick regime (e.g. Mayer et al 2007). We present several tests of this method: (1) The evolution of a 0.07 solar mass protoplanetary disc around a 0.5 solarmass star (Pickett et al 2003, Mejia et al 2005, Boley et al 2006, Cai et al 2008); (2) The collapse of a non-rotating 1 solar mass molecular cloud (Masunaga & Inutsuka 2000, Stamatellos et al 2007); (3) The thermal relaxation of temperature fluctuations in an static homogeneous sphere (Masunaga et al 1998, Spiegel 1957, Stamatellos et al 2007)
description: 4 pages, 6 figures, to appear in the proceedings of the Cool Stars 15 conference
PowerPoint - Macht und Einfluss eines Präsentationsprogramms
Creators: name: Medienimpulse, Redaktion
Publisher: name: Medienimpulse
Year: 2009

description: S. Fischer Verlag Frankfurt am Main Dezember 2009
description: Medienimpulse, Bd. 47 Nr. 2 (2009): 2/2009 - Computerspiele
Medienkompetenz für ErzieherInnen. Ein Handbuch für die moderne Medienpraxis in der frühen Bildung
Creators: name: Düssel, Mareike
Publisher: name: Medienimpulse
Year: 2009

description: Kopaed, München 2007 ISBN 3-86736-004-9
description: Medienimpulse, Bd. 47 Nr. 2 (2009): 2/2009 - Computerspiele
Coastlines violate the Schramm-Loewner Evolution
Creators: name: Abril, Leidy M. L.
name: Oliveira, Erneson A.
name: Moreira, André A.
name: Andrade, José S.
name: Herrmann, Hans J.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Mandelbrot's empirical observation that the coast of Britain is fractal has been confirmed by many authors, but it can be described by the Schramm--Loewner Evolution? Since the self-affine surface of our planet has a positive Hurst exponent, one would not expect a priori any critical behavior. Here, we investigate numerically the roughness and fractal dimension of the isoheight lines of real and artificial landscapes. Using a novel algorithm to take into account overhangs, we find that the roughness exponent of isoheight lines is consistent with unity regardless of the Hurst exponent of the rough surface. Moreover, the effective fractal dimension of the iso-height lines decays linearly with the Hurst exponent of the surface. We perform several tests to verify if the complete and accessible perimeters would follow the Schramm--Loewner Evolution and find that the left passage probability test is clearly violated, implying that coastlines violate SLE.
description: 17 pages, 11 figures
How Big Are Peoples' Computer Files? File Size Distributions Among User-managed Collections
Creators: name: Dinneen, Jesse David
name: Nguyen, Ba Xuan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Improving file management interfaces and optimising system performance requires current data about users' digital collections and particularly about the file size distributions of such collections. However, prior works have examined only the sizes of system files and users' work files in varied contexts, and there has been no such study since 2013; it therefore remains unclear how today's file sizes are distributed, particularly personal files, and further if distributions differ among the major operating systems or common occupations. Here we examine such differences among 49 million files in 348 user collections. We find that the average file size has grown more than ten-fold since the mid-2000s, though most files are still under 8 MB, and that there are demographic and technological influences in the size distributions. We discuss the implications for user interfaces, system optimisation, and PIM research.
description: Final version to appear in ASIS&T `21: Proceedings of the 84th Annual Meeting of the Association for Information Science & Technology, 58
Exploring mutual information between IRIS spectral lines. II. Calculating the most probable response in all spectral windows
Creators: name: Panos, Brandon
name: Kleint, Lucia
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: A three-dimensional picture of the solar atmosphere's thermodynamics can be obtained by jointly analyzing multiple spectral lines that span many formation heights. In paper I, we found strong correlations between spectral shapes from a variety of different ions during solar flares in comparison to the quiet Sun. We extend these techniques to address the following questions: which regions of the solar atmosphere are most connected during a solar flare, and what are the most likely responses across several spectral windows based on the observation of a single Mg II spectrum? Our models are derived from several million IRIS spectra collected from 21 M- and X-class flares. We applied this framework to archetypal Mg II flare spectra, and analyzed the results from a multi-line perspective. We find that (1) the line correlations from the photosphere to the transition region are highest in flare ribbons. (2) Blue-shifted reversals appear simultaneously in Mg II, C II, and Si IV during the impulsive phase, with Si IV displaying possible optical depth effects. Fe II shows signs of strong emission, indicating deep early heating. (3) The Mg II line appears to typically evolve a blue-shifted reversal that later returns to line center and becomes single peaked within 1-3 minutes. The widths of these single peaked profiles slowly erode with time. During the later flare stages, strong red wing enhancements indicating coronal rain are evident in Mg II, C II, and Si IV. Our framework is easily adaptable to any multi-line data set, and enables comprehensive statistical analyses of the atmospheric behavior in different spectral windows.
Hydrodynamic radial and elliptic flow in heavy-ion collisions from AGS to LHC energies
Creators: name: Kestin, Gregory
name: Heinz, Ulrich W
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Using ideal relativistic hydrodynamics in 2+1 dimensions, we study the collision energy dependence of radial and elliptic flow, of the emitted hadron spectra, and of the transverse momentum dependence of several hadronic particle ratios, covering the range from Alternating Gradient Synchrotron (AGS) to Large Hadron Collider (LHC) energies. These calculations establish an ideal fluid dynamic baseline that can be used to assess non-equilibrium features manifest in future LHC heavy-ion experiments. Contrary to earlier suggestions we find that a saturation and even decrease of the differential elliptic flow v_2(p_T) with increasing collision energy cannot be unambiguously associated with the QCD phase transition.
description: 10 pages, 6 figures. References and two footnotes added. To appear in European Physical Journal C in Hard Probes 2008 Special Topics Issue