cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Femtosecond x rays from laser-plasma accelerators
Creators: name: Corde, S.
name: Phuoc, K. Ta
name: Beck, A.
name: Lambert, G.
name: Fitour, R.
name: Lefebvre, E.
name: Malka, V.
name: Rousse, A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Accelerator Physics (physics.acc-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Relativistic interaction of short-pulse lasers with underdense plasmas has recently led to the emergence of a novel generation of femtosecond x-ray sources. Based on radiation from electrons accelerated in plasma, these sources have the common properties to be compact and to deliver collimated, incoherent and femtosecond radiation. In this article we review, within a unified formalism, the betatron radiation of trapped and accelerated electrons in the so-called bubble regime, the synchrotron radiation of laser-accelerated electrons in usual meter-scale undulators, the nonlinear Thomson scattering from relativistic electrons oscillating in an intense laser field, and the Thomson backscattered radiation of a laser beam by laser-accelerated electrons. The underlying physics is presented using ideal models, the relevant parameters are defined, and analytical expressions providing the features of the sources are given. Numerical simulations and a summary of recent experimental results on the different mechanisms are also presented. Each section ends with the foreseen development of each scheme. Finally, one of the most promising applications of laser-plasma accelerators is discussed: the realization of a compact free-electron laser in the x-ray range of the spectrum. In the conclusion, the relevant parameters characterizing each sources are summarized. Considering typical laser-plasma interaction parameters obtained with currently available lasers, examples of the source features are given. The sources are then compared to each other in order to define their field of applications.
description: 58 pages, 41 figures
Die „Neue Gasse" in Rottweil - Eine Bresche im hochmittelalterlichen Stadtgrundriß
Creators: name: King, Stefan
name: Wittmann, Werner
Publisher: name: Südwestdeutsche Beiträge zur historischen Bauforschung
Year: 2016

description: [nicht vorhanden / not available]
description: Südwestdeutsche Beiträge zur historischen Bauforschung, Bd. 5 (2002)
Anchusa arvensis L.
Creators: name: Becherer
Publisher: name: Zenodo
Year: 1956
Subjects: Biodiversity
Taxonomy

description: S. arvensis L. Cat. 291. l: Salvan (J.). - 3:Riddes (Besse).
description: Published as part of Becherer, 1956, Florae Vallesiacae Supplementum, pp. 1-556 in Denkschriften der Schweizerischen Naturforschenden Gesellschaft 71 on pages 1-556
Der Specksepplehof - Chronik eines untergegangenen Kulturdenkmals und Anmerkungen zur Typologie im Vergleich mit anderen Bauernhäusern der Region
Creators: name: King, Stefan
Publisher: name: Südwestdeutsche Beiträge zur historischen Bauforschung
Year: 2016

description: [nicht vorhanden / not available]
description: Südwestdeutsche Beiträge zur historischen Bauforschung, Bd. 5 (2002)
Remote frequency measurement of the 1S 0→ 3P 1 transition in laser-cooled 24Mg
Creators: name: Friebe, J.
name: Riedmann, M.
name: Wübbena, T.
name: Pape, A.
name: Kelkar, H.
name: Ertmer, Wolfgang
name: Terra, O.
name: Sterr, Uwe
name: Weyers, S.
name: Grosche, G.
name: Schnatz, H.
name: Rasel, Ernst Maria
Publisher: name: Bristol : IOP Publishing Ltd.
Year: 2011
Subjects: subject: Atom-light interactions
subject: Atomic ensemble
subject: Free fall
subject: Frequency measurements
subject: High temperature
subject: Laser-cooled
subject: Magnesium atom
subject: Motion of atoms
subject: Physikalisch-technische bundesanstalt
subject: Telecom fibers
subject: Theoretical models
subject: Transition frequencies
subject: Uncertainty budget
subject: Atoms
subject: Frequency standards
subject: Laser cooling
subject: Magnesium
subject: Atomic spectroscopy
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: We perform Ramsey-Bordé spectroscopy on laser-cooled magnesium atoms in free fall to measure the 1S 0→ 3P 1 intercombination transition frequency. The measured value of 655 659 923 839 730 (48) Hz is consistent with our former atomic beam measurement (Friebe et al 2008 Phys. Rev. A 78 033830). We improve upon the fractional accuracy of the previous measurement by more than an order of magnitude to 7×10 -14. The magnesium frequency standard was referenced to a fountain clock of the Physikalisch Technische Bundesanstalt (PTB) via a phase-stabilized telecom fiber link and its stability was characterized for interrogation times up to 8000 s. The high temperature of the atomic ensemble leads to a systematic shift due to the motion of atoms across the spectroscopy beams. In our regime, this leads to a counterintuitive reduction of residual Doppler shift with increasing resolution. Our theoretical model of the atom-light interaction is in agreement with the observed effect and allows us to quantify its contribution in the uncertainty budget.
Cyclic Cosmology from the Little Rip
Creators: name: Frampton, Paul H.
name: Ludwick, Kevin J.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We revisit a cyclic cosmology scenario proposed in 2007 to examine whether its hypotheses can be sustained if the underlying big rip evolution, which was assumed there, is replaced by the recently proposed little rip. We show that the separation into causal patches at turnaround is generally valid for a little rip, and therefore conclude that the little rip is equally as suitable a basis for cyclicity as is the big rip.
description: 5 pages. arXiv admin note: substantial text overlap with arXiv:hep-th/0610213
Bericht über die Tätigkeit der Römisch-Germanischen Kommission vom 1. April 1933 bis 31. März 1934
Creators: name: Bersu, Gerhard
name: Zeiß, Hans
Publisher: name: Bericht der Römisch-Germanischen Kommission
Year: 2016

description: [nicht vorhanden / not available]
description: Bericht der Römisch-Germanischen Kommission, Bd. 23 (1933): Bericht der Römisch-Germanischen Kommission
Multi-temporal time-dependent terrain visualization through localized spatial correspondence parameterization
Creators: name: Dalyot, Sagi
name: Doytsher, Y.
Publisher: name: Basel : MDPI AG
Year: 2013
Subjects: subject: Accuracy
subject: DEM/DTM
subject: Hierarchical
subject: Interpolation
subject: Modeling
subject: Morphology
subject: Multi-temporal
subject: Spatio-temporal
subject: Three-dimensional
subject: Visualization
subject: Dewey Decimal Classification::500 | Naturwissenschaften

description: Visualizing quantitative time-dependent changes in the topography requires relying on a series of discrete given multi-temporal topographic datasets that were acquired on a given time-line. The reality of physical phenomenon occurring during the acquisition times is complex when trying to mutually model the datasets; thus, different levels of spatial inter-relations and geometric inconsistencies among the datasets exist. Any straight forward simulation will result in a truncated, ill-correct and un-smooth visualization. A desired quantitative and qualitative modelling is presumed to describe morphologic changes that occurred, so it can be utilized to carry out more precise and true-to-nature visualization tasks, while trying to best describe the reality transition as it occurred. This research paper suggests adopting a fully automatic hierarchical modelling mechanism, hence implementing several levels of spatial correspondence between the topographic datasets. This quantification is then utilized for the datasets morphing and blending tasks required for intermediate scene visualization. The establishment of a digital model that stores the local spatial transformation parameterization correspondences between the topographic datasets is realized. Along with designated interpolation concepts, this complete process ensures that the visualized transition from one topographic dataset to the other via the quantified correspondences is smooth and continuous, while maintaining morphological and topological relations. © 2013 by the authors; licensee MDPI, Basel, Switzerland.
title: Applied element method in the solution of plane problems in the theory of creep
Creators: name: Chepurnenko, A.S.
name: Savchenko, A.A.
name: Chepurnenko, V.S.
Publisher: name: Peter the Great St.Petersburg Polytechnic University
Year: 2019

description: The article deals with the consideration of creep in the solution of plane problems by the applied element method. The derivation of the resolving equations is given, as well as the  solution  of  the  test  problem  for  the  cantilever  beam.  For  calculations,  the  authors  developed a program in the Matlab software package.
Das alte E-Werk in Mössingen. Frühe Stromgewinnung in Württemberg
Creators: name: Blumer, Rolf-Dieter
name: Numberger, Markus
name: Schairer, Christoph
Publisher: name: Denkmalpflege in Baden-Württemberg – Nachrichtenblatt der Landesdenkmalpflege
Year: 2016

description: Denkmalpflege in Baden-Württemberg – Nachrichtenblatt der Landesdenkmalpflege, Bd. 45, Nr. 4 (2016)
A numerical approach to evaluating what percentage of a living space is well-ventilated, for the assessment of thermal comfort
Creators: name: Bastide, Alain
name: Lauret, Alfred Jean Philippe
name: Garde, François
name: Boyer, Harry
Publisher: name: arXiv
Year: 2012
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: A bioclimatic approach to designing comfortable buildings in hot and humid tropical regions requires, firstly, some preliminary, important work on the building envelope to limit the energy contributions, and secondly, an airflow optimization of the building. For the first step, tools such as nodal or zonal models have been largely implemented. For the second step, the assessment of air velocities, in three dimensions and in a large space, can only be performed through the use of detailed models such as with CFD. This paper deals with the improvement of thermal comfort by ventilating around the occupants. For this purpose, the average velocity coefficient definition is modified to be adapted to CFD and the areas involving movement or the living spaces. We propose a new approach based on the derivation of a new quantity: the well-ventilated percentage of a living space. The well-ventilated percentage of a space allows a time analysis of the aeraulic behaviour of the building in its environment. These percentages can be over a period such as one day, a season or a year. These kinds of results are helpful for an architect to configure the rooms of a house according to their uses, the environment, the architectural choices and the constraints related to the design of bioclimatic buildings.
title: A static boundary element analysis of 3D anisotropic elastic problems
Creators: name: Igumnov, L.A.
name: Markov, I.P.
name: Boev, A.V.
Publisher: name: Peter the Great St.Petersburg Polytechnic University
Year: 2019

description: This  paper  presents  a  direct  boundary  element  approach  for  anisotropic  static  three-dimensional  linear  elastic  problems.  Formulation  is  based  on  the  use  of  regularized  boundary  integral  equation  (BIE)  for  displacements.  This  BIE  is  weakly  singular  which  is  advantageous  compared  to  the  traditional  strongly  singular  formulations.  The  displacement static  fundamental  solution  is  expressed  in  terms  of  an  integral  over  a  circumference  with  a  unit  radius.  For  the  efficient  numerical  implementation  of  these  fundamental  solutions  an  interpolation  scheme  is  used.  For  the  spatial  discretization  a  mixed  approximation  of  geometry  and  boundary  fields is  employed.  Numerical  solutions  of  the  problem  of  spherical  cavity  in  an  infinite  elastic  medium  subjected  to  the  uniform  internal  pressure  are  presented  for the materials with different degrees of anisotropy.
Radiation pattern analysis of antenna systems for MIMO and diversity configurations
Creators: name: Klemp, O.
name: Eul, H.
Publisher: name: Göttingen : Copernicus GmbH
Year: 2005
Subjects: subject: Analytical description
subject: Antenna configurations
subject: Eigen-mode expansion
subject: Envelope correlation
subject: Multi-element antennas
subject: Next-generation wireless communications
subject: Radiation characteristics
subject: Transmission systems
subject: Channel capacity
subject: Communication systems
subject: MIMO systems
subject: Radiation effects
subject: Receiving antennas
subject: Directional patterns (antenna)
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: Multiple-input multiple-output (MIMO) antenna systems and antenna configurations for wideband multimode diversity rank among the emerging key technologies in next generation wireless communication systems. The analysis of such transmission systems usually neglects the influences of real antenna radiation characteristics as well as the influences of mutual coupling in a multielement antenna arrangement. Nevertheless, to achieve a detailed description of diversity gain and channel capacity by using several transmit-and receive antennas in a wireless link, it is essential to take all those effects into account. The expansion of the radiation fields in terms of spherical eigenmodes allows an analytical description of the antenna radiation characteristics and accounts for all the coupling effects in multielement antenna configurations. Therefore the radiation pattern analysis by spherical eigenmode expansion provides an efficient alternative to establish an analytical approach in the calculation of envelope correlation or channel capacity. © 2005 Copernicus GmbH.
Energy Conditions in $f(R,T,R_{μν}T^{μν})$ Gravity
Creators: name: Sharif, M.
name: Zubair, M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We discuss the validity of the energy conditions in a newly modified theory named as $f(R,T,R_{μν}T^{μν})$ gravity, where $R$ and $T$ represent the scalar curvature and trace of the energy-momentum tensor. The corresponding energy conditions are derived which appear to be more general and can reduce to the familiar forms of these conditions in general relativity, $f(R)$ and $f(R,T)$ theories. The general inequalities are presented in terms of recent values of Hubble, deceleration, jerk and snap parameters. In particular, we use two specific models recently developed in literature to study concrete application of these conditions as well as Dolgov-Kawasaki instability. Finally, we explore $f(R,T)$ gravity as a specific case to this modified theory for exponential and power law models.
description: 24 pages, no figure. typos corrected, three references added
In Erwartung des Jüngsten Gerichts. Eine wiederentdeckte spätgotische Siechenkapelle im alten Gasthaus zum St. Jakobsbad in Horb am Neckar
Creators: name: Brasse, Christiane
Publisher: name: Denkmalpflege in Baden-Württemberg – Nachrichtenblatt der Landesdenkmalpflege
Year: 2016

description: Denkmalpflege in Baden-Württemberg – Nachrichtenblatt der Landesdenkmalpflege, Bd. 45, Nr. 4 (2016)
How do we identify flash droughts? A case study in Central European Croplands
Creators: name: Alencar, Pedro Henrique Lima
name: Paton, Eva Nora
Publisher: name: IWA Publishing
Year: 2022
Subjects: subject: 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften
subject: climatic compound events
subject: confusion matrix
subject: event identification
subject: flash drought
subject: synchronicity metrics

description: Many definitions and delineation methods exist for identifying flash droughts (FDs), which are events of rapid and unusual large depletion of root-zone soil moisture, in comparison to average moisture conditions, due to climatic compound conditions over a short period of several weeks. Six FD identification methods were compared to analyse their functioning using data from several experimental cropland sites across Central Europe. Co- and misidentification of the FD time series were assessed using confusion and synchronicity metrics on a local scale. Even though a large degree of synchronicity of individual FD events was observed, some divergence in drought periods was detected, which was related to four intrinsic differences in the underlying FD definitions: (1) type of critical variable; (2) velocity of drought intensification; (3) pre-set threshold values for final depletion and/or (4) minimum length of the duration of FDs. To balance the strengths and weaknesses of those methods that are not based on soil moisture, we suggest using an ensemble approach for event identification, which is validated in this study for the temperate central European region. In doing so, the current unclearly defined sub-types of FDs can be detected, regardless of the different combinations of compound drivers and differences in intensification dynamics. All methods were implemented in an R package and are available as a Shiny app for the public.
title: Employment of Eulerian, Lagrangian, and arbitrary Lagrangian-Eulerian description for crack opening problem
Creators: name: Ivanova, E.A.
name: Matyas, D.V.
name: Stepanov, M.D.
Publisher: name: Peter the Great St.Petersburg Polytechnic University
Year: 2019

description: Numerical study of crack opening in the solid material of rock formation is presentedin this article. Initially introduced straight-line crack is widened by increasing internal pressure. The  crack  shape  evolution  resembles  hydraulic  fracturing  and  is  considered  as  a  transient  process.  Commercial  code  LS-DYNA  was  employed  to  obtain  solutions  by  three  types  of  descriptions, they are compared to the solution obtained in Eulerian description by a program based on the finite-volume method and written in Python language. The main features of the self-developed code are a direct relation between velocities and strains, and a deriving of the aperture through density distribution.
A refined complexity analysis of fair districting over graphs
Creators: name: Boehmer, Niclas
name: Koana, Tomohiro
name: Niedermeier, Rolf
Publisher: name: Springer Science and Business Media LLC
Year: 2022
Subjects: subject: 000 Informatik, Informationswissenschaft, allgemeine Werke::000 Informatik, Wissen, Systeme::004 Datenverarbeitung; Informatik
subject: parameterized algorithmics
subject: electoral districting
subject: fairness
subject: social choice on social networks

description: We study the NP-hard FAIR CONNECTED DISTRICTING problem recently proposed by Stoica et al. [AAMAS 2020]: Partition a vertex-colored graph into k connected components (subsequently referred to as districts) so that in every district the most frequent color occurs at most a given number of times more often than the second most frequent color. FAIR CONNECTED DISTRICTING is motivated by various real-world scenarios where agents of different types, which are one-to-one represented by nodes in a network, have to be partitioned into disjoint districts. Herein, one strives for “fair districts” without any type being in a dominating majority in any of the districts. This is to e.g. prevent segregation or political domination of some political party. We conduct a fine-grained analysis of the (parameterized) computational complexity of FAIR CONNECTED DISTRICTING. In particular, we prove that it is polynomial-time solvable on paths, cycles, stars, and caterpillars, but already becomes NP-hard on trees. Motivated by the latter negative result, we perform a parameterized complexity analysis with respect to various graph parameters including treewidth, and problem-specific parameters, including, the numbers of colors and districts. We obtain a rich and diverse, close to complete picture of the corresponding parameterized complexity landscape (that is, a classification along the complexity classes FPT, XP, W[1]-hard, and para-NP-hard).
3D Smoothed Particle Hydrodynamics Models of Betelgeuse's Bow Shock
Creators: name: Mohamed, Shazrene
name: Mackey, Jonathan
name: Langer, Norbert
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Betelgeuse, the bright red supergiant (RSG) in Orion, is a runaway star. Its supersonic motion through the interstellar medium has resulted in the formation of a bow shock, a cometary structure pointing in the direction of motion. We present the first 3D hydrodynamic simulations of the formation and evolution of Betelgeuse's bow shock. We show that the bow shock morphology depends substantially on the growth timescale for Rayleigh-Taylor versus Kelvin-Helmholtz instabilities. We discuss our models in light of the recent Herschel, GALEX and VLA observations. If the mass in the bow shock shell is low (~few x 0.001 Msun), as seems to be implied by the AKARI and Herschel observations, then Betelgeuse's bow shock is very young and is unlikely to have reached a steady state. The circular, smooth bow shock shell is consistent with this conclusion. We further discuss the implications of our results, in particular, the possibility that Betelgeuse may have only recently entered the RSG phase.
description: 9 pages, 4 figures, Betelgeuse workshop, November 2012, Paris. To be published in the European Astronomical Society Publications Series, editors: Pierre Kervella, Thibaut Le Bertre & Guy Perrin
Carbon-Based Electrodes for Advanced Zinc-Air Batteries: Oxygen-Catalytic Site Regulation and Nanostructure Design
Creators: name: Shao, Wenjie
name: Yan, Rui
name: Zhou, Mi
name: Ma, Lang
name: Roth, Christina
name: Ma, Tian
name: Cao, Sujiao
name: Cheng, Chong
name: Yin, Bo
name: Li, Shuang
Publisher: name: Springer Science and Business Media LLC
Year: 2023
Subjects: subject: 600 Technik, Medizin, angewandte Wissenschaften::620 Ingenieurwissenschaften::620 Ingenieurwissenschaften und zugeordnete Tätigkeiten
subject: Zn-air batteries
subject: carbon nanostructures
subject: electrocatalysts
subject: oxygen-catalytic catalysts
subject: ORR
subject: OER

description: Zn-air batteries are highly attractive for direct chemical-to-electrical energy conversion and for solving the energy crisis and environmental problems. Designing efficient oxygen electrodes has been considered one of the most critical steps in the development of advanced Zn-air batteries because of the sluggish kinetics of the oxygen reduction reaction and the oxygen evolution reaction. In recent years, nanostructured carbon-based electrodes with large surface areas, efficient oxygen-catalytic centers, and hierarchically porous matrices have provided significant opportunities to optimize the performance of the oxygen electrodes in both primary and rechargeable Zn-air batteries. In this review, we provide a comprehensive summary of the reported nanostructured carbon-based electrodes for advanced Zn-air batteries in terms of tailoring the oxygen-catalytic sites and designing carbon supports. The versatile synthetic strategies, characterization methods, and in-depth understanding of the relationships between the oxygen-catalytic sites/nanostructures and the oxygen electrode performance are systematically summarized. Furthermore, we also briefly outline recent progress in engineering flexible and high-power Zn-air batteries. Ultimately, a thorough discussion of current primary challenges and future perspectives on the rational design of nanostructured carbon-based oxygen electrodes is given, thus providing inspiration for the future prosperity of fast-kinetic and efficient Zn-air batteries in a broad range of energy fields.
Entwurf von zeitkontinuierlichen Σ Δ-Modulatoren - Äquivalenz zwischen zeitkontinuierlichen und zeitdiskreten Systemen [Design of continuous-time ΣΔ-modulators - Equivalence between continuous-time and discrete-time systems]
Creators: name: Anders, J.
name: Mathis, Wolfgang
name: Ortmanns, M.
Publisher: name: Göttingen : Copernicus GmbH
Year: 2007
Subjects: subject: Continuous-time
subject: Discrete time system
subject: Excess loop delay
subject: Nonideality
subject: Stability analysis
subject: Continuous time systems
subject: Design
subject: Digital control systems
subject: Modulators
subject: Discrete time control systems
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: In the article at hand a complete equivalency, i.e. including the input signal, between continuous-time and discrete-time Σ Δ-modulators in state-space is derived. In addition, it is shown, how one can incorporate the important non-ideality of "excess loop delay" into the formalism. The method introduced is supposed to facilitate the design, especially the stability analysis part of the design, of continuoustime Σ Δs by making use of the empirically thoroughly examined discrete-time systems.
description: Im vorliegenden Artikel wird eine vollstängige, d.h. unter Einbeziehung des Eingangssignals, Äquivalenz zwischen zeitkontinuierlichen und zeitdiskreten ΣΔ-Modulatoren im Zustandsraum hergeleitet. Es wird ebenfalls gezeigt, wie eine wichtige Nichtidealität, das sog. "excess loop delay", in den Berechnungen berücksichtigt werden kann. Die dargestellte Methode dient dazu, den Entwurf und dabei vor allem die Stabilitätsuntersuchungen, von zeitkontinuierlichen ΣΔs auf die bereits empirisch intensiv erforschten zeitdiskreten Systeme zurückzuführen.
title: Stress relaxation and creep of a composite material based on epoxy resin filled with the hemp boon
Creators: name:  Ivlev, V.I.
name: Sigachyov, A.F.
name: Yudin, V.A.
Publisher: name: Peter the Great St.Petersburg Polytechnic University
Year: 2019

description: Samples  of  composite  material  based  on  epoxy  resin  and  hemp  boon as  a  filler  were  obtained and studied. The regularities of the processes of mechanical relaxation in this composite material are qualitatively similar to the regularities of these processes in pure cured resin.
60 Jahre documenta. Die Zukunft der Wunderkammer documenta Archiv
Creators: name: Mörsch, Gerd
Publisher: name: AKMB-news: Informationen zu Kunst, Museum und Bibliothek
Year: 2016

description: AKMB-news: Informationen zu Kunst, Museum und Bibliothek, Bd. 21, Nr. 2 (2015): AKMB-news
title: Mechanical studies of rubber micro- and nanocomposites promising for the tire industry. Uniaxial and biaxial tests
Creators: name: Garishin, O.K.
name: Shadrin, V.V.
name: Kornev, Yu.V.
Publisher: name: Peter the Great St.Petersburg Polytechnic University
Year: 2019

description: Complex  studies  of  the  mechanical  properties  of  composites  based  on  rubber vulcanizates  with  various  micro  and  nanofillers  (which  are  already  used  or  intended  to  be  used  in  the  tire  industry)  were  carried  out.  Testing  of  composites  for  uniaxial  stretching  to  rupture  allowed  us  to  determine  the  reinforcing  effects  of  the  input  of  fillers,  as  well  as  materials strength  and  deformability. Cyclic  tests  for  biaxial  loading  in  two  mutually  perpendicular  directions  were  also  carried  out.  As  a  result,  the  effects  of  softening  and  the  occurrence of induced mechanical anisotropy in filled elastomers under the action of a biaxial load  were  studied.  It  was  shown  that  there  are  no  hysteresis  losses  in  the  unfilled  elastomer,  and there is no induced anisotropy. For a filled elastomer, the value of hysteresis and induced anisotropy depend on the type of filler, its concentration and particle size.
Methods for the calibrated measurement of the scattering parameters of planar multi-port devices
Creators: name: Rolfes, I.
name: Schiek, B.
Publisher: name: Göttingen : Copernicus GmbH
Year: 2007
Subjects: subject: Calibration procedure
subject: Complex scattering parameters
subject: Device under test
subject: External reflection
subject: Measurement setup
subject: Measurement system
subject: Planar microwave circuits
subject: Vector network analyzers
subject: Calibration
subject: Design for testability
subject: Error correction
subject: Microwave circuits
subject: Scattering
subject: Scattering parameters
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: In this article, the error-corrected determination of complex scattering parameters of multi-port devices by means of a 2-port vector network analyzer is presented. As only two ports of the device under test can be connected to the analyzer ports at a time, the remaining device ports have to be terminated by external reflections. In order to measure the scattering parameters of the DUT without the influence of systematic errors and of the external terminations, an error correction has to be performed besides the calibration. For this purpose, the application of the multi-port procedure is presented. This method has the advantage, that the external reflective terminations can be chosen arbitrarily. Furthermore, these terminations can be unknown except for one. An automatized measurement system based on a switching network is shown, which is optimized for the measurement of planar microwave circuits. An error model for the description of the measurement setup as well as a calibration procedure for the elimination of the systematic errors are presented.
Direct Gravitational Imaging of Intermediate Mass Black Holes in Extragalactic Halos
Creators: name: Inoue, Kaiki Taro
name: Rashkov, Valery
name: Silk, Joseph
name: Madau, Piero
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A galaxy halo may contain a large number of intermediate mass black holes (IMBHs) with masses in the range of 10^{2-6} solar mass. We propose to directly detect these IMBHs by observing multiply imaged QSO-galaxy or galaxy-galaxy strong lens systems in the submillimeter bands with high angular resolution. The silhouette of an IMBH in the lensing galaxy halo would appear as either a monopole-like or a dipole-like variation at the scale of the Einstein radius against the Einstein ring of the dust-emitting region surrounding the QSO. We use a particle tagging technique to dynamically populate a Milky Way-sized dark matter halo with black holes, and show that the surface mass density and number density of IMBHs have power-law dependences on the distance from the center of the host halo if smoothed on a scale of ~ 1 kpc. Most of the black holes orbiting close to the center are freely roaming as they have lost their dark matter hosts during infall due to tidal stripping. Next generation submillimeter telescopes with high angular resolution (< 0.3 mas) will be capable of directly mapping such off-nuclear freely roaming IMBHs with a mass of ~ 10^6 solar mass in a lensing galaxy that harbours a O(10^9) solar mass supermassive black hole in its nucleus.
description: 7 pages, 6 figures, submitted to MNRAS
Novel algorithms for the characterization of n-port networks by using a two-port network analyzer
Creators: name: Will, B.
name: Rolfes, I.
name: Schiek, B.
Publisher: name: Göttingen : Copernicus GmbH
Year: 2007
Subjects: subject: Least square algorithms
subject: Multi-port method
subject: N-port networks
subject: Reflection factor
subject: Reflection terminations
subject: Scattering matrices
subject: Two-port network
subject: Weak convergence
subject: Algorithms
subject: Electric network analyzers
subject: Equivalent circuits
subject: Scattering
subject: Scattering parameters
subject: Least squares approximations
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: The measurement of the scattering matrices of n-port networks is an important task. For this purpose two ports of the n-port network are connected with the network analyzer and the remaining ports are connected to reflecting terminations. In order to specify the scattering matrix of a n-port network with the multi-port method (Rolfes et al., 2005), n reflecting terminations are required from which at least one reflection factor needs to be known. There are some cases, in which the multi-port method shows weak convergence properties. For example, a T-junction cannot be identified if the reflecting terminations used are short circuits and if the line length is equivalent to a multiple of a half wavelength. This is due to the fact that the two ports connected to the network analyzer become isolated. Two new algorithms, named the sub-determinant method and the wave-identification method, respectively, which employ a second set of reflection terminations that have to differ from the first set, allow to identify every n-port network without the necessity to distinguish different cases. Both methods are based on least square algorithms and allow to determine all scattering parameters of a n-port-network directly and uniquely.
Herzlichen Glückwunsch zum Zwanzigsten!
Creators: name: Schild, Margret
Publisher: name: AKMB-news: Informationen zu Kunst, Museum und Bibliothek
Year: 2016

description: AKMB-news: Informationen zu Kunst, Museum und Bibliothek, Bd. 21, Nr. 2 (2015): AKMB-news
Deformation method for generalized Abelian Higgs-Chern-Simons models
Creators: name: Losano, L.
name: Malbouisson, J. M. C.
name: Rubiera-Garcia, D.
name: Santos, C. dos
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present an extension of the deformation method applied to self-dual solutions of generalized Abelian Higgs-Chern-Simons models. Starting from a model defined by a potential $V(| ϕ|)$ and a non-canonical kinetic term $ω(| ϕ|) | D_μϕ|^2$ whose analytical domain wall solutions are known, we show that this method allows to obtain an uncountable number of new analytical solutions of new models defined by other functions $\widetilde{V}$ and $\widetildeω$. We present some examples of deformation functions leading to new families of models and their associated analytic solutions.
description: 6 pages, 10 figures
„Sichtbar gemachte Kommunikation“. Zum Tod des Buchkünstlers Kurt Löb (1926 – 2015)
Creators: name: Weinke, Wilfried
Publisher: name: AKMB-news: Informationen zu Kunst, Museum und Bibliothek
Year: 2016

description: AKMB-news: Informationen zu Kunst, Museum und Bibliothek, Bd. 21, Nr. 2 (2015): AKMB-news
Obstacle-based self-calibration techniques for the determination of the permittivity of liquids
Creators: name: Rolfes, I.
Publisher: name: Göttingen : Copernicus GmbH
Year: 2007
Subjects: subject: Calibration measurements
subject: Parameter characterization
subject: Reflection measurements
subject: Self-calibration method
subject: Self-calibration procedures
subject: Self-calibration techniques
subject: Two-port calibration
subject: Vector network analyzers
subject: Calibration
subject: Dielectric properties of liquids
subject: Liquids
subject: Permittivity
subject: Scattering parameters
subject: Parameter estimation
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: In this contribution, different obstacle-based self-calibration techniques for the measurement of the dielectric properties of liquids are investigated at microwave frequencies. The liquid under test is contained inside a waveguide, which is connected to the ports of a vector network analyzer. The permittivity of the liquid is characterized on the basis of the measured scattering parameters. In order to extract the material parameters precisely and to eliminate systematic errors of the setup, calibration measurements have to be performed. For this purpose, different self-calibration methods based on the displacement of an obstacle are considered. The presented methods differ in that way, that either transmission and reflection measurements or purely reflection measurements are performed. All these methods have in common that the material parameters are already calculable within a so-called self-calibration procedure. Thus, a full two-port calibration of the whole setup is not necessary. Furthermore, the methods can be realized effectively in a practical setup having the advantage that a rearrangement of the setup is not needed for the material parameter measurements and that the liquid under investigation can pass continuously through the measurement cell. This might be of interest for the application in an industrial process, enabling the continuous flow of the material while the parameter characterization can take place at the same time.
A Comparison between CODYRUN and TRNSYS, simulation models for thermal buildings behaviour
Creators: name: Lucas, Franck
name: Mara, Thierry Alex
name: Garde, François
name: Boyer, Harry
Publisher: name: arXiv
Year: 2012
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: Simulation codes of thermal behaviour could significantly improve housing construction design. Among the existing software, CODYRUN and TRNSYS are calculations codes of different conceptions. CODYRUN is exclusively dedicated to housing thermal behaviour, whereas TRNSYS is more generally used on any thermal system. The purpose of this article is to compare these two instruments in two different conditions . We will first modelize a mono-zone test cell, and analyse the results by means of signal treatment methods. Then, we will modelize a real case of multi-zone housing, representative of housing in wet tropical climates. We could so evaluate influences of meteorological and building description data on model errors.
Kunstgeschichte in Bonn – traditionsbewusst und trotzdem modern
Creators: name: Häger-Weigel, Elisabeth
Publisher: name: AKMB-news: Informationen zu Kunst, Museum und Bibliothek
Year: 2016

description: AKMB-news: Informationen zu Kunst, Museum und Bibliothek, Bd. 21, Nr. 2 (2015): AKMB-news
Measurement of the transient shielding effectiveness of enclosures using UWB pulses inside an open TEM waveguide
Creators: name: Herlemann, H.
name: Koch, M.
Publisher: name: Göttingen : Copernicus GmbH
Year: 2007
Subjects: subject: Cylindrical enclosure
subject: Electric and magnetic fields
subject: Frequency domain measurement
subject: Magnetic shielding effectiveness
subject: Measurement procedures
subject: Shielding effectiveness
subject: Shielding materials
subject: Transient electromagnetic fields
subject: Electromagnetic fields
subject: Enclosures
subject: Magnetic shielding
subject: Waveguides
subject: Ultra-wideband (UWB)
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: Recently, new definitions of shielding effectiveness (SE) for high-frequency and transient electromagnetic fields were introduced by Klinkenbusch (2005). Numerical results were shown for closed as well as for non closed cylindrical shields. In the present work, a measurement procedure is introduced using ultra wideband (UWB) electromagnetic field pulses. The procedure provides a quick way to determine the transient shielding effectiveness of an enclosure without performing time consuming frequency domain measurements. For demonstration, a cylindrical enclosure made of conductive textile is examined. The field pulses are generated inside an open TEM-waveguide. From the measurement of the transient electric and magnetic fields with and without the shield in place, the electric and magnetic shielding effectiveness of the shielding material as well as the transient shielding effectiveness of the enclosure are derived.
Hypomorphic Sperner systems and nonreconstructible functions
Creators: name: Couceiro, Miguel
name: Lehtonen, Erkko
name: Schölzel, Karsten
Publisher: name: arXiv
Year: 2013
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: A reconstruction problem is formulated for Sperner systems, and infinite families of nonreconstructible Sperner systems are presented. This has an application to a reconstruction problem for functions of several arguments and identification minors. Sperner systems being representations of certain monotone functions, infinite families of nonreconstructible functions are thus obtained. The clones of Boolean functions are completely classified in regard to reconstructibility.
description: 38 pages
Radiation characteristics of a coaxial waveguide with eccentric inner conductor for application in hyperthermia and microwave reflex therapy
Creators: name: Herschmann, R.
name: Büchel, Olivier
Publisher: name: Göttingen : Copernicus GmbH
Year: 2007
Subjects: subject: Bipolar coordinates
subject: Coaxial waveguides
subject: Equivalent current density
subject: Huygens principle
subject: Near field radiation
subject: Near-field area
subject: Power densities
subject: Radiation characteristics
subject: Electromagnetic fields
subject: Radiators
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: This paper examines the radiation characteristics of a contact emitter conceived for application in hyperthermia and microwave reflex therapy. It is important to analyse the distribution of power density in the near field area, as the radiator's therapeutic sphere of activity is localized here. The contact emitter is a coaxial radiator with an eccentric course of the inner conductor. According to Huygens principle, a theoretical view of the near field radiation characteristics is made by determining the equivalent current densities in the emitter aperture. It is shown that by an eccentric shift of the inner conductor, an almost isotropic near field radiation pattern and power density can be achieved. For this, the electromagnetic field in the emitter aperture is determined by using a Bipolar coordinate system. This calculation considers only the fundamental TEM mode of the contact emitter. Besides the theoretical results near and far fields are simulated using the programme system Ansoft HFSS.
van der Waals interaction in iron-chalcogenide superconductors
Creators: name: Ricci, Fabio
name: Profeta, Gianni
Publisher: name: arXiv
Year: 2013
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We demonstrate that the inclusion of van der Waals dispersive interaction sensibly improves the prediction of lattice constants by density functional theory in iron-chalcogenides (FeCh) superconductor compounds, namely FeSe and FeTe. We show how generalized gradient approximation (GGA) for the exchange correlation potential overestimates the out-of-plane lattice constants in both compounds when compared with experiments. In addition, GGA predicts a too weak bonding between the neutral FeCh layers, with a sensible underestimation of the bulk modulus. van der Waals corrected simulations completely solve both problems, reconciling theoretical results with experiments. These findings must be considered when dealing with theoretical predictions in FeCh compounds.
Thermal Building Simulation and Computer Generation of Nodal Models
Creators: name: Boyer, H.
name: Chabriat, J. P.
name: Grondin-Perez, B.
name: Tourrand, C.
name: Brau, J.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: The designer's preoccupation to reduce the energy needs and get a better thermal quality of ambiances helped in the development of several packages simulating the dynamic behaviour of buildings. This paper shows the adaptation of a method of thermal analysis, the nodal analysis, linked to the case of building's thermal behaviour. We take successively an interest in the case of conduction into a wall, in the coupling with superficial exchanges and finally in the constitution of thermal state models of the building. Big variations existing from one building to another, it's necessary to build the thermal model from the building description. This article shows the chosen method in the case of our thermal simulation program for buildings, CODYRUN
An X-ray cooling-core cluster surrounding a low power Compact Steep Spectrum Radio source 1321+045
Creators: name: Kunert-Bajraszewska, M.
name: Siemiginowska, A.
name: Labiano, A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We discovered an X-ray cluster in a Chandra observation of the compact steep spectrum (CSS) radio source 1321+045 (z=0.263). CSS sources are thought to be young radio objects at the beginning of their evolution and can potentially test the cluster heating process. 1321+045 is a relatively low luminosity source and its morphology consists of two radio lobes on the opposite sides of a radio core with no evidence for jets or hotspots. The optical emission line ratios are consistent with an interstellar medium (ISM) dominated by AGN-photoionization with a small contribution from star formation, and no contributions from shocks. Based on these ratios, we classify 1321+045 as a low excitation galaxy (LEG) and suggest that its radio activity is in a coasting phase. The X-ray emission associated with the radio source is detected with 36.1+/-8.3 counts, but the origin of this emission is highly uncertain. The current X-ray image of the cluster does not show any signatures of a radio source impact on the cluster medium. Chandra detects the cluster emission at >3 sigma level out to ~60 arcsec (~240 kpc). We obtain the best fit beta model parameters of the surface brightness profile of beta=0.58+/-0.2 and a core radius of 9.4^{+1.1}_{-0.9} arcsec. The average temperature of the cluster is equal to kT=4.4^{+0.5}_{-0.3} keV, with a temperature and cooling profile indicative of a cooling core. We measure the cluster luminosity L_(0.5-2 keV)=3x10^{44} erg s^{-1} and mass 1.5x10^{14} M_sun.
description: 4 pages, 1 figure, 1 table, accepted for publication in ApJ Letters
Protective properties of a missile enclosure against electromagnetic influences
Creators: name: Fisahn, Sven
name: Garbe, Heyno
Publisher: name: Göttingen : Copernicus GmbH
Year: 2007
Subjects: subject: Electromagnetic influence
subject: Electronic systems
subject: Hollow cylinders
subject: Protective properties
subject: Shielding effectiveness
subject: Simulations and measurements
subject: Cylinders (shapes)
subject: Enclosures
subject: Magnetic shielding
subject: Missiles
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: In order to predict the immunity of a generic missile (GENEC), not only the electronic system but also the enclosure has to be taken into consideration. While a completely closed metallic missile enclosure shows a high electric shielding effectiveness, it is decreased substantially by apertures which could not be avoided by different reasons. The shielding effectiveness of the generic missile could be investigated by means of a hollow cylinder equipped with different apertures. Numerical simulations and measurements of this hollow cylinder will be carried out and analyzed.