cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Messtechnische Verifikation der Eigenschaft „Unintentional Radiator“ für ein reales Objekt
Creators: name: Brech, Henrik
name: Menßen, Benjamin
name: Garbe, Heyno
Publisher: name: Aachen : Apprimus
Year: 2016
Subjects: subject: elektromagnetische Störfelder
subject: unbeabsichtigte Strahler
subject: Messtechnik
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: Die Messung der elektromagnetischen Störaussendung elektronischer Geräte ist ein wesentlicher Aspekt im Bereich der elektromagnetischen Verträglichkeit (EMV). In [1] wird die Problematik bei der Betrachtung von elektrisch großen Objekten beschrieben. Es wird darauf verwiesen, dass aktuelle Messverfahren den Charakter unbeabsichtigter Strahler [2] insbesondere für Frequenzen oberhalb 1 GHz nicht korrekt erfassen, da „Unbeabsichtigte Strahler“ die Eigenschaft besitzen, dass die Richtung der maximalen Störaussendung nicht a priori bestimmbar ist. Dies lässt sich durch transiente und stochastische elektronische Prozesse innerhalb der komplexen Leitungsstrukturen des Objekts erklären. Stochastische Ansätze sollen diese Problematik greifbar machen und die vorhandenen Messverfahren dahingehend erweitern. Ein Ansatz zur Beschreibung der maximalen Direktivität von unbeabsichtigten Strahlern wird in [3] vorgestellt. Bezugsgröße für den Verlauf der maximalen Direktivität ist die elektrische Größe ka des Objekts. Diese Ansätze wurden u. a. in [4] schon in Simulationen an generischen Objekten verifiziert. Eine Verifikation anhand von Messungen an realen Objekten steht jedoch noch aus. Dazu wurde in dieser Arbeit die Hauptplatine eines Desktop-PCs ausgewählt. Die Untersuchung von transienten und stochastischen Prozessen ist dabei nicht trivial. Die Wahl des Messgerätes sowie des zu wählenden Modus zur Detektion der Emission werfen Probleme auf, wie z. B. die Nichtdetektion von transienten Signalanteilen. Diese Problematik soll in dieser Arbeit näher beleuchtet werden, so dass eine Empfehlung bezüglich des notwendigen Messverfahrens ausgesprochen werden kann. Schließlich soll anhand der Ergebnisse eine Diskussion über die Größe des EUTs geführt werden, ähnlich wie es in [5] angeregt wurde.
Time-evolution of tripartite quantum discord and entanglement under local and non-local random telegraph noise
Creators: name: Buscemi, Fabrizio
name: Bordone, Paolo
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Few studies explored the dynamics of non-classical correlations besides entanglement in open multipartite quantum systems. Here, we address the time-evolution of quantum discord and entanglement in a model of three non-interacting qubits subject to a classical random telegraph noise in common and separated environments. Two initial entangled states of the system are examined, namely the GHZ- and W-type states. The dynamics of quantum correlations results to be strongly affected by the input configuration of the qubits, the type of the system-environment interaction, and the memory properties of the environmental noise. When the qubits are non-locally coupled to the random telegraph noise, the GHZ-type states partially preserve, at long times, both discord and entanglement, regardless the correlation time of the environmental noise. The survived entangled states turn out to be also detectable by means of suitable entanglement witnesses. On the other hand, in the same conditions, the decohering effects suppress all the quantum correlation of the W-type states which are thus less robust than the GHZ-type ones. The long-time survival of tripartite discord and entanglement opens interesting perspectives in the use of multipartite entangled states for practical applications in quantum information science.
description: 11 pages, 4 figures
PT deformation of Calogero-Sutherland models
Creators: name: Correa, F.
name: Lechtenfeld, O.
Publisher: name: Heidelberg : Springer Verlag
Year: 2019
Subjects: subject: Field Theories in Lower Dimensions
subject: Global Symmetries
subject: Integrable Field Theories
subject: Integrable Hierarchies
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: Calogero-Sutherland models of N identical particles on a circle are deformed away from hermiticity but retaining a PT symmetry. The interaction potential gets completely regularized, which adds to the energy spectrum an infinite tower of previously non-normalizable states. For integral values of the coupling, extra degeneracy occurs and a nonlinear conserved supersymmetry charge enlarges the ring of Liouville charges. The integrability structure is maintained. We discuss the AN −1-type models in general and work out details for the cases of A2 and G2. © 2019, The Author(s).
El Greco + Exile
Creators: name: Keeney, Gavin
Publisher: name: Zenodo
Year: 2024

description: “El Greco + Exile” (workshop presentation), Workshop on World Literature and Law, Benjamin N. Cardozo School of Law, New York, NY, USA (August 2023)

“El Greco + Exile” examines the peregrinations of Doménikos Theotokópoulos, from Candia to Venice, from Venice to Rome, from Rome to Venice, and from Venice to Toledo (via Madrid) in the second half of the sixteenth century. Within the art he created across this period we find post-Byzantine, Renaissance, and Mannerist influences, while, as of the 1580s, we find him jettisoning all such influences in favor of an indefinable style that art historians will argue over for 300 years, before labeling it proto-expressionist. Upon being resurrected by French artists in the 1860s (e.g., the anti-academicians Manet, Delacroix, Millet et al.), a 100-year war over “ownership” of El Greco occurs between the Italians, the Spanish, and the Greeks, with decidedly “nationalistic” overtones. Called “Il Greco,” “El Greco,” and even “Le Greco,” across this 100-year war, the premise is that he suffered a self-imposed double or triple exile, belonging to “no one.”
description: PDF of the PPT presented.
Angular Distribution of Bremsstrahlung Produced by 10-keV and 20-keV Electrons Incident on a Thick Au Target
Creators: name: Gonzales, D.
name: Williams, S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: The relative intensities of the thick-target bremsstrahlung produced by 10-keV and 20-keV electrons incident on Au at forward angles ranging from 0 degrees to 25 degrees are compared. Following corrections for photon absorption within the target, the detected radiation appears to be distributed anisotropically only for photon energies, k, that are approximately equal to the initial energy of the incident electrons, E. The results are compared to the theoretical angular distributions of Kissel et al. [At. Data Nucl. Data Tables 28, 381 (1983)]. The comparison suggests that when k/E is approximately equal to 1, the angular distribution of bremsstrahlung emitted by electrons incident on thick targets is similar to the theoretical angular distribution of bremsstrahlung emitted by electrons incident on free-atom targets.
description: The following article has been accepted by AIP Conference Proceedings (Vol. 1525). After it is published, it will be found at http://proceedings.aip.org/
Effectiveness of Light-Quality and Dark-White Growth Light Shifts in Short-Term Light Acclimation of Photosynthesis in Arabidopsis
Creators: name: Hommel, Elisabeth
name: Liebers, Monique
name: Offermann, Sascha
name: Pfannschmidt, Thomas
Publisher: name: Lausanne : Frontiers Media
Year: 2022
Subjects: subject: dark-light shifts
subject: light-quality control
subject: photosynthesis
subject: photosystem II super-complexes
subject: state transitions
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: Photosynthesis needs to run efficiently under permanently changing illumination. To achieve this, highly dynamic acclimation processes optimize photosynthetic performance under a variety of rapidly changing light conditions. Such acclimation responses are acting by a complex interplay of reversible molecular changes in the photosynthetic antenna or photosystem assemblies which dissipate excess energy and balance uneven excitation between the two photosystems. This includes a number of non-photochemical quenching processes including state transitions and photosystem II remodeling. In the laboratory such processes are typically studied by selective illumination set-ups. Two set-ups known to be effective in a highly similar manner are (i) light quality shifts (inducing a preferential excitation of one photosystem over the other) or (ii) dark-light shifts (inducing a general off-on switch of the light harvesting machinery). Both set-ups result in similar effects on the plastoquinone redox state, but their equivalence in induction of photosynthetic acclimation responses remained still open. Here, we present a comparative study in which dark-light and light-quality shifts were applied to samples of the same growth batches of plants. Both illumination set-ups caused comparable effects on the phosphorylation of LHCII complexes and, hence, on the performance of state transitions, but generated different effects on the degree of state transitions and the formation of PSII super-complexes. The two light set-ups, thus, are not fully equivalent in their physiological effectiveness potentially leading to different conclusions in mechanistic models of photosynthetic acclimation. Studies on the regulation of photosynthetic light acclimation, therefore, requires to regard the respective illumination test set-up as a critical parameter that needs to be considered in the discussion of mechanistic and regulatory aspects in this subject. Copyright © 2022 Hommel, Liebers, Offermann and Pfannschmidt.
Implementation of the sectional aerosol module SALSA2.0 into the PALM model system 6.0: Model development and first evaluation
Creators: name: Kurppa, M.
name: Hellsten, A.
name: Roldin, P.
name: Kokkola, H.
name: Tonttila, J.
name: Auvinen, M.
name: Kent, C.
name: Kumar, P.
name: Maronga, Björn
name: Järvi, L.
Publisher: name: Göttingen : Copernicus GmbH
Year: 2019
Subjects: subject: air quality
subject: SALSA2.0
subject: PALM
subject: condensation
subject: dissolutional growth
subject: Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften

description: Urban pedestrian-level air quality is a result of an interplay between turbulent dispersion conditions, background concentrations, and heterogeneous local emissions of air pollutants and their transformation processes. Still, the complexity of these interactions cannot be resolved by the commonly used air quality models. By embedding the sectional aerosol module SALSA2.0 into the large-eddy simulation model PALM, a novel, high-resolution, urban aerosol modelling framework has been developed. The first model evaluation study on the vertical variation of aerosol number concentration and size distribution in a simple street canyon without vegetation in Cambridge, UK, shows good agreement with measurements, with simulated values mainly within a factor of 2 of observations. Dispersion conditions and local emissions govern the pedestrian-level aerosol number concentrations. Out of different aerosol processes, dry deposition is shown to decrease the total number concentration by over 20 %, while condensation and dissolutional increase the total mass by over 10 %. Following the model development, the application of PALM can be extended to local- and neighbourhood-scale air pollution and aerosol studies that require a detailed solution of the ambient flow field. © 2019. This work is distributed under the Creative Commons Attribution 4.0 License.
Improved Source/Absorber Preparation for Radionuclide Spectrometry Based on Low-Temperature Calorimetric Detectors
Creators: name: Bockhorn, L.
name: Paulsen, M.
name: Beyer, J.
name: Kossert, K.
name: Loidl, M.
name: Nähle, O.J.
name: Ranitzsch, P.C.-O.
name: Rodrigues, M.
Publisher: name: Heidelberg : Springer Verlag
Year: 2020
Subjects: subject: Beta spectrometry
subject: Low-temperature detectors
subject: Preparation techniques
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: High-resolution beta spectrometry based on low-temperature calorimetric detectors requires high-quality source/absorber combinations in order to avoid spectrum artifacts and to achieve optimal detection efficiency. In this work, preparation techniques and quality control methods to fabricate reliable source/absorber assemblies with the radionuclide under investigation embedded into them are discussed. © 2019, The Author(s).
On geometric interpretation of the Berry phase
Creators: name: Katanaev, M. O.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A geometric interpretation of the Berry phase and its Wilczek--Zee non-Abelian generalization are given in terms of connections on principal fiber bundles. It is demonstrated that a principal fiber bundle can be trivial in all cases, while the connection and its holonomy group are nontrivial. Therefore, the main role is played by geometric rather than topological effects.
description: 11 pages
Messtechnische Verifizierung eines analytischen Modells für geschirmte Magnetfeldantennen mittels kontaktloser Impedanzmessung
Creators: name: Harm, Martin
name: Küllmer, Alexander
name: Enders, Achim
Publisher: name: Aachen : Apprimus
Year: 2016
Subjects: subject: Magnetfeldantenne
subject: Impedanzmessung
subject: Messtechnik
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: Für die Messung von Feldstärken im Frequenzbereich bis 30 MHz werden üblicherweise breitbandige geschirmte Magnetfeldantennen eingesetzt. Um die gewünschte Breitbandigkeit zu erreichen, werden die Antennen unterresonant betrieben und müssen somit elektrisch klein sein. Üblicherweise wird angenommen, dass die Antenne elektrisch klein ist, wenn ihr Umfang kleiner als ein Zehntel der Wellenläge bleibt, bei 30 MHz ist der maximale Antennenumfang also 1 m. Zum Schutz vor elektrischen Störfeldern ist die Leiterschleife mit einem leitfähigen Schirm umgeben. Um keine Kurzschlusswindung zu erzeugen, ist dieser ist mit einem Schlitz versehen, der mittig auf der senkrechten Symmetrieachse liegt. Im Fußpunkt der Antenne münden die beiden geschirmten, gleichlangen Antennenarme in ein Fußpunktnetzwerk (FPN), das die Verbindung zum Messempfänger mit üblicherweise koaxialem Anschluss herstellt. In Abbildung 1 ist der Aufbau einer solchen Antenne schematisch dargestellt. Verschiedene Untersuchungen [1,4] zu gängigen Kalibrierverfahren für Magnetfeldantennen haben gezeigt, dass die Antennenfaktoren auch vom jeweiligen verfahren abhängen. Zur Weiterentwicklung der Kalibrierverfahren ist ein genaues Verständnis der Funktionsweise geschirmter Magnetfeldantennen unumgänglich. Ein valides analytisches Modell ist dazu ein unentbehrliches Werkzeug und wird im Rahmen dieser Veröffentlichung vorgestellt.
Spectral and transport properties of the two-dimensional Lieb lattice
Creators: name: Niţă, M.
name: Ostahie, B.
name: Aldea, A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The specific topology of the line centered square lattice (known also as the Lieb lattice) induces remarkable spectral properties as the macroscopically degenerated zero energy flat band, the Dirac cone in the low energy spectrum, and the peculiar Hofstadter-type spectrum in magnetic field. We study here the properties of the finite Lieb lattice with periodic and vanishing boundary conditions. We find out the behavior of the flat band induced by disorder and external magnetic and electric fields. We show that in the confined Lieb plaquette threaded by a perpendicular magnetic flux there are edge states with nontrivial behavior. The specific class of twisted edge states, which have alternating chirality, are sensitive to disorder and do not support IQHE, but contribute to the longitudinal resistance. The symmetry of the transmittance matrix in the energy range where these states are located is revealed. The diamagnetic moments of the bulk and edge states in the Dirac-Landau domain, and also of the flat states in crossed magnetic and electric fields are shown.
description: 29 pages, 18 figures
In vitro corrosion of ZEK100 plates in Hank's Balanced Salt Solution
Creators: name: Waizy, Hazibullah
name: Weizbauer, Andreas
name: Modrejewski, Christian
name: Witte, Frank
name: Windhagen, Henning
name: Lucas, Arne
name: Kieke, Marc D.K.
name: Denkena, Berend
name: Behrens, Peter
name: Meyer-Lindenberg, Andrea
name: Bach, Friedrich-Wilhelm
name: Thorey, Fritz
Publisher: name: London : BioMed Central Ltd.
Year: 2012
Subjects: subject: Corrosion
subject: In vitro study
subject: Magnesium alloy
subject: Plates
subject: Corrosion property
subject: Degradation behavior
subject: Four-point bending test
subject: Hank's balanced salt solutions
subject: In-vitro
subject: Mg content
subject: Natural bone
subject: Orthopedic implant
subject: Physiological condition
subject: Resorbable materials
subject: Stress shielding
subject: Calcium phosphate
subject: Magnesium
subject: Magnesium alloys
subject: Mechanical properties
subject: Salt removal
subject: Surfaces
subject: Magnesium printing plates
subject: alloy
subject: bicarbonate
subject: biomaterial
subject: Hanks Balanced Salt Solution
subject: isotonic solution
subject: magnesium
subject: article
subject: chemistry
subject: corrosion
subject: hydrodynamics
subject: immersion
subject: mechanics
subject: surface property
subject: Alloys
subject: Bicarbonates
subject: Biocompatible Materials
subject: Hydrodynamics
subject: Immersion
subject: Isotonic Solutions
subject: Mechanical Processes
subject: Surface Properties
subject: Dewey Decimal Classification::600 | Technik
subject: Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: Background: In recent years magnesium alloys have been intensively investigated as potential resorbable materials with appropriate mechanical and corrosion properties. Particularly in orthopedic research magnesium is interesting because of its mechanical properties close to those of natural bone, the prevention of both stress shielding and removal of the implant after surgery.Methods: ZEK100 plates were examined in this in vitro study with Hank's Balanced Salt Solution under physiological conditions with a constant laminar flow rate. After 14, 28 and 42 days of immersion the ZEK100 plates were mechanically tested via four point bending test. The surfaces of the immersed specimens were characterized by SEM, EDX and XRD.Results: The four point bending test displayed an increased bending strength after 6 weeks immersion compared to the 2 week group and 4 week group. The characterization of the surface revealed the presence of high amounts of O, P and Ca on the surface and small Mg content. This indicates the precipitation of calcium phosphates with low solubility on the surface of the ZEK100 plates.Conclusions: The results of the present in vitro study indicate that ZEK100 is a potential candidate for degradable orthopedic implants. Further investigations are needed to examine the degradation behavior.
MPEC 2023-V234 : 2018 VN7
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
A Λ-Fleming-Viot type model with intrinsically varying population size
Creators: name: Kern, Julian
name: Wiederhold, Bastian
Publisher: name: Weierstrass Institute
Year: 2023
Subjects: subject: Fleming-Viot
subject: Λ-Fleming-Viot
subject: Wright-Fisher
subject: measure-valued Markov process
subject: martingale probem
subject: lookdown construction
subject: coalescent
subject: Markov Mapping Theorem
subject: varying population size
subject: Lévy process
subject: 60J25
subject: 60G51
subject: 60J90

description: We propose an extension of the classical ?-Fleming-Viot model to intrinsically varying pop- ulation sizes. During events, instead of replacing a proportion of the population, a random mass dies and a, possibly different, random mass of new individuals is added. The model can also incorporate a drift term, representing infinitesimally small, but frequent events. We investigate el- ementary properties of the model, analyse its relation to the Λ-Fleming-Viot model and describe a duality relationship. Through the lookdown framework, we provide a forward-in-time analysis of fixation and coming down from infinity. Furthermore, we present a new duality argument allowing one to deduce well-posedness of the measure-valued process without the necessity of proving uniqueness of the associated lookdown martingale problem.
Spin-polarized (001) surface states of the topological crystalline insulator Pb_{0.73}Sn_{0.27}Se
Creators: name: Wojek, B. M.
name: Buczko, R.
name: Safaei, S.
name: Dziawa, P.
name: Kowalski, B. J.
name: Berntsen, M. H.
name: Balasubramanian, T.
name: Leandersson, M.
name: Szczerbakow, A.
name: Kacman, P.
name: Story, T.
name: Tjernberg, O.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We study the nature of (001) surface states in Pb_{0.73}Sn_{0.27}Se in the newly discovered topological-crystalline-insulator (TCI) phase as well as the corresponding topologically trivial state above the band-gap-inversion temperature. Our calculations predict not only metallic surface states with a nontrivial chiral spin structure for the TCI case, but also nonmetallic (gapped) surface states with nonzero spin polarization when the system is a normal insulator. For both phases, angle- and spin-resolved photoelectron spectroscopy measurements provide conclusive evidence for the formation of these (001) surface states in Pb_{0.73}Sn_{0.27}Se, as well as for their chiral spin structure.
description: 6 pages, 2 figures
Ion-implanted PERC solar cells with Al2O3/SiN x rear passivation
Creators: name: Dullweber, Thorsten
name: Hesse, Rene
name: Bhosle, Vikram
name: Dubé, Chris
Publisher: name: London : Elsevier Ltd.
Year: 2013
Subjects: subject: Ion implantation
subject: Phosphorus emitter
subject: Silicon solar cells
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Ion implantation is an attractive candidate for PERC solar cells due to the single-sided emitter phosphorus doping. The oxide, which is formed during the implant anneal, can be used as rear passivation of PERC cells. However, the SiO2/SiNx rear passivation is very sensitive to the rear surface roughness and surface preparation. Hence, in this paper we evaluate Al2O3/SiNx rear passivation layers in combination with an oxide passivated ion-implanted emitter. We obtain emitter saturation current densities of 93 fA/cm2, which is significantly lower compared to a typical POCl3 diffused emitter with 140 fA/cm2. Ion-implanted PERC cells with Al2O 3/SiNx rear passivation show conversion efficiencies up to 20.0% which is comparable to POCl3-diffused PERC cells. The emitter dopant profile can be adjusted by the thermal budget of the anneal in order to optimize the process window between Jsc and FF losses. The IQE and reflectance of implanted and POCl3-diffused PERC cells in the long wavelength regime are almost identical which demonstrates the successful implementation of the Al2O3/SiNx rear passivation to PERC cells with ion-implanted emitters. Future work will focus on simplifying the process flow in order to obtain a lean industrially manufacturable PERC process, leveraging the single side doping via ion implantation.
title: Die „California Digital Open Source Library“: Entstehung, Herausforderungen, Vorbild für Deutschland?
Creators: name: Hermann, Sybille
Publisher: name: University Library Heidelberg
Year: 2015

description: Um den Zugang zu Bildung zu erleichtern, gibt es seit einigen Jahren Bestrebungen, Lehrinhalte kostenlos zur Verfügung zu stellen. Die UNESCO führte den Begriff „Open Educational Resources“ ein, um diese Inhalte zu bezeichnen. Die Notwendigkeit, freie Bildungsressourcen für jedermann bereitzustellen, wird vor allem in den USA, aber inzwischen auch in Deutschland diskutiert. Da Lehrbücher in den USA sehr teuer sind und viele Studenten diese nicht mehr erwerben können, ist es dort seit einigen Jahren das Ziel, nicht nur Vorlesungen, sondern auch Lehrbücher online frei zur Verfügung zu stellen. Um diese Open Textbooks auffindbar zu machen, wurden Plattformen wie die „California Digital Open Source Library“ aufgebaut. Dieser Aufsatz stellt deren Entwicklung dar und diskutiert Probleme, die bei ihrer Einführung auftraten, sowie die Bedeutung der Verwendung von Open Textbooks in Deutschland. Abschließend wird beleuchtet, welche Rolle die Bibliotheken bei Etablierung von freien Lehrinhalten einnehmen können.
description: Perspektive Bibliothek, Bd. 4, Nr. 1 (2015), Beginn und Erscheinungsfrequenz: Nummer: 1, Jahr: 2012, Bände pro Jahr: 1
Solar Flare X-ray Source Motion as a Response to Electron Spectral Hardening
Creators: name: O'Flannagain, A.
name: Gallagher, P.
name: Brown, J.
name: Milligan, R.
name: Holman, G.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context: Solar flare hard X-rays (HXRs) are thought to be produced by nonthermal coronal electrons stopping in the chromosphere, or remaining trapped in the corona. The collisional thick target model (CTTM) predicts that sources produced by harder power-law injection spectra should appear further down the legs or footpoints of a flare loop. Therefore, hardening of the injected power-law electron spectrum during flare onset should be concurrent with a descending hard X-ray source. Aims: To test this implication of the CTTM by comparing its predicted HXR source locations with those derived from observations of a solar flare which exhibits a nonthermally-dominated spectrum before the peak in HXRs, known as an early impulsive event. Methods: HXR images and spectra of an early impulsive C-class flare were obtained using the Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). Images were reconstructed to produce HXR source height evolutions for three energy bands. Spatially-integrated spectral analysis was performed to isolate nonthermal emission, and to determine the power-law index of the electron injection spectrum. The observed height-time evolutions were then fit with CTTM-based simulated heights for each energy. Results: A good match between model and observed source heights was reached, requiring a density model that agreed well with previous studies of flare loop densities. Conclusions: The CTTM has been used to produce a descent of model HXR source heights that compares well with observations of this event. Based on this interpretation, downward motion of nonthermal sources should indeed occur in any flare where there is spectral hardening in the electron distribution during a flare. However, this would often be masked by thermal emission associated with flare plasma pre-heating.
description: 8 pages, 5 figures
title: On the Determination of the Number of Positive and Negative Polynomial Zeros and Their Isolation
Creators: name: Prodanov, Emil
Publisher: name: Technological University of Dublin
Year: 2019

description: A novel method with two variations is proposed with which the number of positive and negative zeros of a polynomial with real co-efficients and degree $n$ can be restricted with significantly better determinacy than that provided by the Descartes' rule of signs and also isolate quite successfully the zeros of the polynomial. The method relies on solving equations of degree smaller than that of the given polynomial. One can determine analytically the exact number of positive and negative zeros of a polynomial of degree up to and including five and also fully isolate the zeros of the polynomial analytically and with one of the variations of the method, one can analytically approach polynomials of degree up to and including nine by solving equations of degree no more than four. For polynomials of higher degree, either of the two variations of the method should be applied recursively. Classification of the roots of the cubic equation, together with their isolation intervals, is presented. Numerous examples are given.
Evaluation of a Pyrometric-based Temperature Measuring Process for the Laser Transmission Welding
Creators: name: Wippo, V.
name: Devrient, M.
name: Kern, M.
name: Jaeschke, P.
name: Frick, T.
name: Stute, U.
name: Schmidt, M.
name: Haferkamp, H.
Publisher: name: Amsterdam : Elsevier B.V.
Year: 2012
Subjects: subject: contour welding
subject: Laser transmission welding
subject: pyrometer
subject: quasi-simultaneous welding
subject: Konferenzschrift
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: An on-axis pyrometric-based temperature measurement method suitable for different laser transmission welding techniques is presented. A temperature detection during contour and quasi-simultaneous welding is demonstrated to fit the requirements of laser transmission welding with part adapted temperature fields. For the experiments a pyrometer is connected to a scanner optic with a non-color-corrected lens. The experiments are performed with a high-speed pyrometer detecting in spectral range of 1.65 - 2.1 μm. Potential errors caused by the measurement method are evaluated and its limits depend on the welding technique performed are examined by creating different defects in the weld seam.
title: Ambient temperature gas phase sulfonation: A mild route towards acid functionalized ordered mesoporous organosilica
Creators: name: Sandbrink, Lennart
name: Lazaridis, Timon
name: Rose, Marcus
name: Palkovits, Regina
Publisher: name: Elsevier
Year: 2023

description: Sulfonation is a versatile method for the production of acidic materials, e. g. for applications in catalysis. In this study different sulfonation techniques for the production of acidic ordered mesoporous materials are investigated. SBA-15-like mesoporous organosilanes bearing aromatic moieties are sulfonated in the liquid phase with oleum as well as in the gas phase under significantly milder conditions with sulfur trioxide. Functionalization via liquid phase sulfonation at elevated temperatures proceeds at the expense of partial or complete collapse of the pore system. In contrast, gas phase sulfonation with sulfur trioxide at ambient temperature allows for similar sulfonation yields, while maintaining the textural properties due to the milder reaction conditions. Overall, acid functionalization of mesoporous organosilica using a gas phase sulfonation route is reported for the first time, enabling both high acid capacities and preservation of the pore structure.
title: A Deep Recurrent Q Network Towards Self-adapting Distributed Microservices Architecture (in press)
Creators: name: Magableh, Basel
Publisher: name: Technological University of Dublin
Year: 2019

description: One desired aspect of microservices architecture is the ability to self-adapt its own architecture and behaviour in response to changes in the operational environment. To achieve the desired high levels of self-adaptability, this research implements the distributed microservices architectures model, as informed by the MAPE-K model. The proposed architecture employs a multi adaptation agents supported by a centralised controller, that can observe the environment and execute a suitable adaptation action. The adaptation planning is managed by a deep recurrent Q-network (DRQN). It is argued that such integration between DRQN and MDP agents in a MAPE-K model offers distributed microservice architecture with self-adaptability and high levels of availability and scalability. Integrating DRQN into the adaptation process improves the effectiveness of the adaptation and reduces any adaptation risks, including resources over-provisioning and thrashing. The performance of DRQN is evaluated against deep Q-learning and policy gradient algorithms including: i) deep q-network (DQN), ii) dulling deep Q-network (DDQN), iii) a policy gradient neural network (PGNN), and iv) deep deterministic policy gradient (DDPG). The DRQN implementation in this paper manages to outperform the above mentioned algorithms in terms of total reward, less adaptation time, lower error rates, plus faster convergence and training times. We strongly believe that DRQN is more suitable for driving the adaptation in distributed services-oriented architecture and offers better performance than other dynamic decision-making algorithms.
Progress on tilted axis cranking covariant density functional theory for nuclear magnetic and antimagnetic rotation
Creators: name: Meng, J.
name: Peng, J.
name: Zhang, S. Q.
name: Zhao, P. W.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Magnetic rotation and antimagnetic rotation are exotic rotational phenomena observed in weakly deformed or near-spherical nuclei, which are respectivelyinterpreted in terms of the shears mecha-nism and two shearslike mechanism. Since their observations, magnetic rotation and antimagnetic rotation phenomena have been mainly investigated in the framework of tilted axis cranking based on the pairing plus quadrupole model. For the last decades, the covariant density functional theory and its extension have been proved to be successful in describing series of nuclear ground-states and excited states properties, including the binding energies, radii, single-particle spectra, resonance states, halo phenomena, magnetic moments, magnetic rotation, low-lying excitations, shape phase transitions, collective rotation and vibrations, etc. This review will mainly focus on the tilted axis cranking covariant density functional theory and its application for the magnetic rotation and antimagnetic rotation phenomena.
description: 53 pages, 19 figures
High-resolution 3D photopolymerization assisted by upconversion nanoparticles for rapid prototyping applications
Creators: name: Rocheva, Vasilina V.
name: Koroleva, Anastasia V.
name: Savelyev, Alexander G.
name: Khaydukov, Kirill V.
name: Generalova, Alla N.
name: Nechaev, Andrey V.
name: Guller, Anna E.
name: Semchishen, Vladimir A.
name: Chichkov, Boris
name: Khaydukov, Evgeny V.
Publisher: name: London : Nature Publishing Group
Year: 2018
Subjects: subject: Three-dimensional (3D) rapid prototyping technology
subject: upconversion nanoparticles
subject: rapid prototyping applications
subject: Dewey Decimal Classification::500 | Naturwissenschaften

description: Three-dimensional (3D) rapid prototyping technology based on near-infrared light-induced polymerization of photocurable compositions containing upconversion nanomaterials has been explored. For this aim, the rationally-designed core/shell upconversion nanoparticles NaYF4:Yb3+,Tm3+/NaYF4, with the distinct ultraviolet-emitting lines and unprecedentedly high near-infrared to ultraviolet conversion efficiency of η UC UV=2% η UC (UV) = 2 % have been used. The upconverted ultraviolet photons were capable to efficiently activate photoinitiators contained in light-sensitive resins under moderate intensities of NIR excitation below 10 W cm-2 and induce generation of radicals and photopolymerization in situ. Near infrared-activated polymerization process, both at the millimeter and sub-micron scales, was investigated. Polymeric macro-and microstructures were fabricated by means of near infrared laser scanning photolithography in the volume of liquid photocurable compositions with focused laser light at 975 nm wavelength. Examination of the polymerization process in the vicinity of the nanoparticles shows strong differences in the rate of polymer shell growth on flat and edge nanoparticle sides. This phenomenon mainly defines the resolution of the demonstrated near infrared-ultraviolet 3D printing technology at the micrometer scale level.
Solving Heat Conduction Problems by the Direct Meshless Local Petrov-Galerkin (DMLPG) method
Creators: name: Mirzaei, Davoud
name: Schaback, Robert
Publisher: name: arXiv
Year: 2013
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: As an improvement of the Meshless Local Petrov-Galerkin (MLPG), the Direct Meshless Local Petrov-Galerkin (DMLPG) method is applied here to the numerical solution of transient heat conduction problem. The new technique is based on direct recoveries of test functionals (local weak forms) from values at nodes without any detour via classical moving least squares (MLS) shape functions. This leads to an absolutely cheaper scheme where the numerical integrations will be done over low-degree polynomials rather than complicated MLS shape functions. This eliminates the main disadvantage of MLS based methods in comparison with finite element methods (FEM), namely the costs of numerical integration.
Magnesium corrosion particles do not interfere with the immune function of primary human and murine macrophages
Creators: name: Roth, Isabelle
name: Schumacher, Stephan
name: Basler, Tina
name: Baumert, Kathrin
name: Seitz, Jan-Marten
name: Evertz, Florian
name: Mueller, Peter Paul
name: Baeumer, Wolfgang
name: Kietzmann, Manfred
Publisher: name: Heidelberg : Springer Heidelberg
Year: 2015
Subjects: subject: degradation
subject: immunotoxic
subject: infection
subject: inflammation
subject: in vitro
subject: phagocytes
subject: biodegradable magnesium
subject: in-vivo
subject: titanium particles
subject: biocompatibility
subject: implants
subject: alloys
subject: cytokines
subject: induce
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie
subject: Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit

description: Magnesium is currently under investigation as a prospective biodegradable implant material. Biodegradation of magnesium causes a release of magnesium, hydroxide ions and hydrogen gas but it can also lead to the formation of particulate debris. Implant-derived particles may have immunotoxic effects. To investigate the influence of magnesium-derived particles on the immune functions of primary macrophages, up to 500 mu g/ml magnesium or magnesium corrosion particles were added to the cell culture medium. No major effects were observed on cell viability and on the release of the proinflammatory cytokine tumor necrosis factor (TNF)alpha. In addition, the ability of macrophages to stimulate proliferation of allogenic lymphocytes in a mixed leukocyte reaction remained unaffected. When macrophages were incubated with magnesium particles and then infected with the apathogenic Mycobacterium smegmatis, infection-induced TNF alpha secretion from murine macrophages was inhibited but not from human macrophages. However, the bactericidal activity of either cell type was not influenced. In conclusion, magnesium-related particles did not restrict the immune function of macrophages, suggesting that magnesium implants and corrosion particles derived thereof are highly biocompatible and have a low inflammatory potential.
Das SCIDHu-Tiermodell als Beispiel für eine diskordante xenogene Transplantationssituation : Untersuchungen zur Rolle humaner T-Lymphozyten in der Abstoßungsreaktion
Creators: name: Ebensen, Thomas
Publisher: name: Hannover : Universität
Year: 2001
Subjects: subject: SCIDhu
subject: xenogeneic Graft-versus-Host-disease
subject: T-cell xenoresponses
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie
subject: Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit

description: [no abstract]
Five Statistical Questions about the Tree of Life
Creators: name: Popovic, Lea
name: Krikun, Maxim
name: Aldous, David
Publisher: name: arXiv
Year: 2013
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: Stochastic modeling of phylogenies raises five questions that have received varying levels of attention from quantitatively inclined biologists. 1) How large do we expect (from the model) the ration of maximum historical diversity to current diversity to be? 2) From a correct phylogeny of the extant species of a clade, what can we deduce about past speciation and extinction rates? 3) What proportion of extant species are in fact descendants of still-extant ancestral species, and how does this compare with predictions od models? 4) When one moves from trees on species to trees on sets of species (whether traditional higher order taxa or clades from PhyloCode), does one expect trees to become more unbiased as a purely logical consequence of tree structure, without signifying any real biological phenomenon? 5) How do we expect that fluctuation rates for counts of higher order taxa should compare with fluctuation rates for number of species? WE present a mathematician's view based on an oversimplified modeling framework in which all these questions can be studied coherently.
description: 11 pages, 3 figures
title: A Framework for Evaluating Model-Driven Self-adaptive Software Systems
Creators: name: Magableh, Basel
Publisher: name: Technological University of Dublin
Year: 2019

description: In the last few years, Model Driven Development (MDD), Component-based Software Development (CBSD), and context-oriented software have become interesting alternatives for the design and construction of self-adaptive software systems. In general, the ultimate goal of these technologies is to be able to reduce development costs and effort, while improving the modularity, flexibility, adaptability, and reliability of software systems. An analysis of these technologies shows them all to include the principle of the separation of concerns, and their further integration is a key factor to obtaining high-quality and self-adaptable software systems. Each technology identifies different concerns and deals with them separately in order to specify the design of the self-adaptive applications, and, at the same time, support software with adaptability and context-awareness. This research studies the development methodologies that employ the principles of model-driven development in building self-adaptive software systems. To this aim, this article proposes an evaluation framework for analysing and evaluating the features of model-driven approaches and their ability to support software with self-adaptability and dependability in highly dynamic contextual environment. Such evaluation framework can facilitate the software developers on selecting a development methodology that suits their software requirements and reduces the development effort of building self-adaptive software systems. This study highlights the major drawbacks of the propped model-driven approaches in the related works, and emphasise on considering the volatile aspects of self-adaptive software in the analysis, design and implementation phases of the development methodologies. In addition, we argue that the development methodologies should leave the selection of modelling languages and modelling tools to the software developers.
title: A 3D Simulation of the Sky at Ballycroy National Park Visitor Centre, Co. Mayo
Creators: name: Prendergast, Frank
Publisher: name: Technological University of Dublin
Year: 2018

description: The Mayo Dark Skies Community Group, in collaboration with Dr Frank Prendergast of the Dublin Institution of Technology, is pleased to launch a digital virtual experience of the Mayo Dark Sky Park. Following its designation as an International Dark Sky Park (Gold Tier), it is now possible to experience a part of this magnificent and pristine skyscape on your computer. This has been made possible using open source software (Stellarium http://www.stellarium.org/) and a specially commissioned digital panorama of the horizon surrounding the Ballycroy National Park Visitor Centre.

Stellarium is an open source planetarium for your computer and shows a fully realistic digital sky. The customised landscape file for Stellarium has been specially developed for this collaborative project. Once installed on your computer, this situates your viewpoint at the summit directly above the Visitor Centre. Real horizons are seen on the screen and, for the first time, the changing skyscapes throughout the year can be experienced and enjoyed. User control over the programme’s location, time and direction settings provides an incredibly powerful educational tool to learn practical astronomy.

A customised landscape file for Ballycroy, a display poster of the panorama surrounding the Visitor Centre and installation instructions on how to install the software and landscape file are available at http://www.mayodarkskypark.ie/discover/Stellarium
title: Context Oriented Software Middleware
Creators: name: Magableh, Basel
Publisher: name: Technological University of Dublin
Year: 2019

description: This article proposes a new paradigm for building an adaptive middleware that supports software systems with self-adaptability and dependability. In this article, we wish to explore how far we can support the engineering of self- adaptive applications using a generic and platform-independent middleware architecture provided by non-specialised programming languages such as Context-Oriented Programming (COP), and Aspect-Oriented Programming (AOP), and not limited to a specific platform or framework. This gives the software developers the flexibility to construct a self-adaptive application using a generic and reusable middleware components that employ popular design patterns, instead of forcing the software developers to use a specific programming language or framework to implement self- adaptive software in mobile computing environment, which are heterogeneous and resource-constrained.

Our middleware approach, Context-Oriented Software Middleware (COSM), supports context-dependent soft- ware with self-adaptability and dependability in a mobile computing environment. The COSM-middleware is a generic and platform-independent adaptation engine, which performs a runtime composition of the software’s context-dependent behaviours based on the execution contexts. Our middleware distinguishes between the context-dependent and context-independent functionality of software systems. This enables the COSM-middleware to adapt the application behaviour by composing a set of context-oriented components, that implement the context-dependent functionality of the software. Accordingly, the software dependability is achieved by considering the functionality of the COSM-middleware and the adaptation impact/costs. The COSM-middleware uses a dynamic policy-based engine to evaluate the adaptation outputs, and verify the fitness of the adaptation output with the application’s objectives, goals and the architecture quality attributes. These capabilities are demonstrated through an empirical evaluation of a case study implementation.