cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Topology of Bendless Three-Dimensional Orthogonal Graph Drawing
Creators: name: Eppstein, David
Publisher: name: arXiv
Year: 2007
Subjects: subject: Computational Geometry (cs.CG)
subject: Combinatorics (math.CO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: F.2.2

description: We consider embeddings of 3-regular graphs into 3-dimensional Cartesian coordinates, in such a way that two vertices are adjacent if and only if two of their three coordinates are equal (that is, if they lie on an axis-parallel line) and such that no three points lie on the same axis-parallel line; we call a graph with such an embedding an xyz graph}. We describe a correspondence between xyz graphs and face-colored embeddings of the graph onto two-dimensional manifolds, and we relate bipartiteness of the xyz graph to orientability of the underlying topological surface. Using this correspondence, we show that planar graphs are xyz graphs if and only if they are bipartite, cubic, and three-connected, and that it is NP-complete to determine whether an arbitrary graph is an xyz graph. We also describe an algorithm with running time O(n 2^{n/2}) for testing whether a given graph is an xyz graph.
description: 23 pages, 16 figures. A much shorter version of this paper will appear at Graph Drawing 2008. This version incorporates feedback from the GD reviewers and new material on covering maps
Visitationen im Deutschen Orden im Mittelalter. Teil 1: 1236-1449; Teil 2: 1450-1519
Creators: name: Jähnig, Bernhart
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 2006

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 55 Nr. 4 (2006)
Anomalously large measured thermoelectric power factor in Sr$_{1-x}$La$_x$TiO$_3$ thin films due to SrTiO$_3$ substrate reduction
Creators: name: Scullin, Matthew L.
name: Yu, Choongho
name: Huijben, Mark
name: Mukerjee, Subroto
name: Seidel, Jan
name: Zhan, Qian
name: Moore, Joel
name: Majumdar, Arun
name: Ramesh, R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report the observation that thermoelectric thin-films of La-doped SrTiO3 grown on SrTiO3 substrates yield anomalously high values of thermopower to give extraordinary values of power factor at 300K. Thin-films of Sr0.98La0.02TiO3, grown via pulsed laser deposition at low temperature and low pressure (450C, 10-7Torr), do not yield similarly high values when grown on other substrates. The thin-film growth induces oxygen reduction in the SrTiO3 crystals, doping the substrate n-type. It is found that the backside resistance of the SrTiO3 substrates is as low (~12ohm/square) as it is on the film-side after film growth.
description: 12 pages, 3 figures, pdf format
Otfried Krafft, Papsturkunde und Heiligsprechung. Die päpstlichen Kanonisationen vom Mittelalter bis zur Reformation. Ein Handbuch
Creators: name: Könighaus, Waldemar
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 2006

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 55 Nr. 4 (2006)
Hans Fenske, Die Verwaltung Pommerns 1815-1945. Aufbau und Ertrag
Creators: name: Unterstell, Rembert
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 1997

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 46 Nr. 2 (1997)
Slow magneto-acoustic waves in simulations of a solar plage region carry enough energy to heat the chromosphere
Creators: name: Yadav, Nitin
name: Cameron, Robert H.
name: Solanki, Sami K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We study the properties of slow magneto-acoustic waves that are naturally excited due to turbulent convection and investigate their role in the energy balance of a plage region using three dimensional (3D) radiation-MHD simulations. We calculate the horizontally averaged (over the whole domain) frequency power spectra for both longitudinal and vertical (i.e. the component perpendicular to the surface) components of velocity. To compare our results with the observations we degrade the simulation data with Gaussian kernels having FWHM of 100 km and 200 km, and calculate horizontally averaged power spectra for the vertical component of velocity. The power spectra of the longitudinal component of velocity, averaged over field lines in the core of a kG magnetic flux concentration, reveal that the dominant period of oscillations shifts from around 6.5 minutes in the photosphere to around 4 minutes in the chromosphere. At the same time, the velocity power spectra, averaged horizontally over the whole domain, show that low frequency waves (approximately 6.5 minute period) may reach well into the chromosphere. Importantly, waves with frequencies above 5 mHz propagating along different field lines are found to be out of phase with each other even within a single magnetic concentration. The horizontally averaged power spectra of the vertical component of velocity at various effective resolutions show that the observed acoustic wave energy fluxes are underestimated, by a factor of three even if determined from observations carried out at a high spatial resolution of 200 km. Our results show that longitudinal waves carry (just) sufficient energy to heat the chromosphere in solar plage. We conjecture that current observations (with spatial resolution around 200 km) underestimate the energy flux by roughly a factor of three, or more if the observations have lower spatial resolution.
description: Accepted for publication in A & A
Das Schicksal des tschechisch-slowakischen Bilingualismus. Eine langsam fortschreitende halbseitige Lähmung
Creators: name: Blahak, Boris
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 2006

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 55 Nr. 4 (2006)
Precision study of K^\pm\toπ^\pmπ^0π^0 and K^\pm\toπ^\pmπ^+π^- Dalitz plot distributions by NA48/2
Creators: name: Goudzovski, Evgueni
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The NA48/2 experiment at the CERN SPS has collected an unprecedented sample of $K^\pm\to3π$ decays. The high statistics and the good resolution of the detectors allow a unique investigation of the detailed phase space distributions of these decays. The effects of final state pion rescattering observed in the Dalitz plot distribution of the $K^\pm\toπ^\pmπ^0π^0$ decays turned out to be a powerful tool for extraction of the S-wave $ππ$ scattering lengths. The large statistics also allowed a precise measurement of the Dalitz plot slope parameters for the $K^\pm\to3π^\pm$ decays.
description: Talk given at Kaon'07 Conference, LNF, Frascati, Italy, 21--25 May, 2007. A version revised by PoS referee
Summary of Cotton Fiber and Processing Test Results, Crop of 1969
Creators: name: Consumer And Marketing Service
name: Consumer And Marketing Service
Publisher: name: Unknown
Year: 1970
Subjects: subject: Crop Production/Industries
subject: Marketing
subject: FOS: Economics and business
subject: Research and Development/Tech Change/Emerging Technologies
subject: Research Methods/ Statistical Methods

description: Excerpts from the report Introduction: This is one of a series of annual reports containing information on fiber properties and spinning performance of cotton from all major commercial production areas of the United States. The results of fiber and spinning tests made in connection with the annual quality surveys are used to check on the effectiveness of the standards to be sure they continue to reflect differences in spinning utility. Data derived from these surveys provide the basis for studies of relationships between various fiber properties and processing performance. Timely publication of the results of these surveys enables farmers and breeders to use the data as a source of quality information regarding cottons produced under commercial conditions. Merchants and manufacturers also use these results to locate sources of cotton having properties and spinning performance desirable for specific uses
Children’s concepts about the slope of a line graph
Creators: name: Dayson, Gaynor
Publisher: name: University of British Columbia
Year: 2010

description: This study is concerned with how children interpret the slope of a line graph. Today with the vast accumulations of data which are available from computers, people are being faced with an ever increasing amount of pictorial representation of this data. Therefore it is of the utmost importance that children understand pictorial representation. Yet in spite of the popularity of graphs as tools of communication, studies show that many adults experience difficulty in reading information presented in a graphical form. The slope of the graph was chosen for this investigation because it is in this aspect of graphing (as shown by the results of the 1981 B.C. Assessment) that children in British Columbia seem to have the greatest difficulty when they reach Grade 8. The study dealt with positive, negative, zero and infinite slopes, combinations of these slopes, curvilinear graphs and qualitative graphs, that is, graphs that have no numerical data shown on the axes. The researcher chose to use a structured individual interview as a means of collecting data about how the students interpreted the slope of a line graph. Graphs used in the interviews dealt with temperature, height, weight and distance. Twenty-two students were chosen for this study. The students were found to have problems mainly with graphs dealing with distance related to time. This problem may be due to the fact that many students read only one axis and when interpreting distance seem to include direction as an added dimension of the graph. Infinite slope graphs were misinterpreted by every student, which may be due to the fact that they ignore the time axis. In general students used two methods of interpreting graphs. In some cases they observed the direction of the graph from left to right, that is, whether the slope went up or down from left to right. In other cases they examined the end points on the graph and drew their conclusions from them. The choice of method varied with the contextual material shown on the graph, which may be due to the children's concept of the parameter in the physical world and whether they see the parameter as being able to increase and decrease over time. From the study the investigator feels that more discussion of graphing by teachers and students is needed if the misconceptions are to be cleared up. Discussion of the parameters of both axes by teachers might help clear up the misconceptions students have about distance travelled over a period of time when this is expressed as a graph. There would be less chance of a graph being read as a map if the relationships between the two axes were demonstrated to students. Teachers also need to be aware of both methods used by students in interpreting graphs.
In Situ Experiment and Modelling of RC-Structure Using Ambient Vibration and Timoshenko Beam
Creators: name: Michel, Clotaire
name: Hans, Stéphane
name: Guéguen, Philippe
name: Boutin, Claude
Publisher: name: arXiv
Year: 2007
Subjects: subject: Geophysics (physics.geo-ph)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: Recently, several experiments were reported using ambient vibration surveys in buildings to estimate the modal parameters of buildings. Their modal properties are full of relevant information concerning its dynamic behaviour in its elastic domain. The main scope of this paper is to determine relevant, though simple, beam modelling whose validity could be easily checked with experimental data. In this study, we recorded ambient vibrations in 3 buildings in Grenoble selected because of their vertical structural homogeneity. First, a set of recordings was done using a 18 channels digital acquisition system (CityShark) connected to six 3C Lennartz 5s sensors. We used the Frequency Domain Decomposition (FDD) technique to extract the modal parameters of these buildings. Second, it is shown in the following that the experimental quasi-elastic behaviour of such structure can be reduced to the behaviour of a vertical continuous Timoshenko beam. A parametric study of this beam shows that a bijective relation exists between the beam parameters and its eigenfrequencies distribution. Consequently, the Timoshenko beam parameters can be estimated from the experimental sequence of eigenfrequencies. Having the beam parameters calibrated by the in situ data, the reliability of the modelling is checked by complementary comparisons. For this purpose, the mode shapes and eigenfrequencies of higher modes are calculated and compared to the experimental data. A good agreement is also obtained. In addition, the beam model integrates in a very synthetic way the essential parameters of the dynamic behaviour.
Charge disproportionation and Hund's insulating behavior in a five-orbital Hubbard model applicable to $d^4$ perovskites
Creators: name: Merkel, Maximilian E.
name: Ederer, Claude
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We explore the transition to a charge-disproportionated insulating phase in a five-orbital cubic tight-binding model applicable to transition-metal perovskites with a formal $d^4$ occupation of the transition-metal cation, such as ferrates or manganites. We use dynamical mean-field theory to obtain the phase diagram as a function of the average local Coulomb repulsion $U$ and the Hund's coupling $J$. The main structure of the phase diagram follows from the zero band-width (atomic) limit and represents the competition between high-spin and low-spin homogeneous and an inhomogeneous charge-disproportionated state. This results in two distinct insulating phases: the standard homogeneous Mott insulator and the inhomogeneous charge-disproportionated insulator, recently also termed Hund's insulator. We characterize the unconventional nature of this Hund's insulating state. Our results are consistent with previous studies of two- and three-orbital models applicable to isolated $t_{2g}$ and $e_g$ subshells, respectively, with the added complexity of the low-spin/high-spin transition. We also test the applicability of an effective two-orbital ($e_g$-only) model with disordered $S=3/2$ $t_{2g}$ core spins. Our results show that the overall features of the phase diagram in the high-spin region are well described by this simplified two-orbital model but also that the spectral features exhibit pronounced differences compared to the full five-orbital description.
Formal Aspects of Quantum Decay
Creators: name: Jiménez, D. F. Ramírez
name: Kelkar, N. G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The Fock-Krylov formalism for the calculation of survival probabilities of unstable states is revisited paying particular attention to the mathematical constraints on the density of states, the Fourier transform of which gives the survival amplitude. We show that it is not possible to construct a density of states corresponding to a purely exponential survival amplitude. he survival probability $P(t)$ and the autocorrelation function of the density of states are shown to form a pair of cosine Fourier transforms. This result is a particular case of the Wiener Khinchin theorem and forces $P(t)$ to be an even function of time which in turn forces the density of states to contain a form factor which vanishes at large energies. Subtle features of the transition regions from the non-exponential to the exponential at small times and the exponential to the power law decay at large times are discussed by expressing $P(t)$ as a function of the number of oscillations, $n$, performed by it. The transition at short times is shown to occur when the survival probability has completed one oscillation. The number of oscillations depend on the properties of the resonant state and a complete description of the evolution of the unstable state is provided by determining the limits on the number of oscillations in each region.
description: 47 pages, 12 figures
Very Large Array Observations of Galactic Center OH 1720 MHz Masers in Sagittarius A East and in the Circumnuclear Disk
Creators: name: Sjouwerman, L. O.
name: Pihlstrom, Y. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present Very Large Array (VLA) radio interferometry observations of the 1720 MHz OH masers in the Galactic Center (GC). Most 1720 MHz OH masers arise in regions where the supernova remnant Sgr A East is interacting with the interstellar medium. The majority of the newly found 1720 MHz OH masers are located to the northeast, independently indicating and confirming an area of shock interaction with the +50 km/s molecular cloud (M-0.02-0.07) on the far side of Sgr A East. The previously known bright masers in the southeast are suggested to be the result of the interaction between two supernova remnants, instead of between Sgr A East and the surrounding molecular clouds as generally found elsewhere in the Galaxy. Together with masers north of the circumnuclear disk (CND) they outline an interaction on the near side of Sgr A East. In contrast to the interaction between the +50 km/s cloud and Sgr A East, OH absorption data do not support a direct interaction between the CND material and Sgr A East. We also present three new high-negative velocity masers, supporting a previous single detection. The location and velocities of the high-negative and high-positive velocity masers are consistent with being near the tangent points of, and physically located in the CND. We argue that the high velocity masers in the CND are pumped by dissipation between density clumps in the CND instead of a shock generated by the supernova remnant. That is, the CND masers are not coupled to the supernova remnant and are sustained independently.
description: accepted to ApJ, 9 pages 3 figures
Minimal $γ$--sheaves
Creators: name: Blickle, Manuel
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: 13N10, 14B05

description: In this note we show that finitely generated unit $O_X[σ]$--modules for $X$ regular and $F$--finite have a minimal root (in the sense of [Lyubeznik, F-modules] Definition~3.6). This problem was posed by Lyubeznik and answered by himself in the case that $X=\Spec R$ is a complete local ring. One immediate consequence of this result is that the parameter test module of tight closure theory commutes with localization. As a further application of the methods in this paper we give new proofs of the results on discreteness and rationality of $F$--thresholds [arXiv:0705.1210] and on $D$-module generation [arXiv:math/0502405v1]. The new proofs are valid in a slightly more general setting such that they also party cover the generalizations recently obtained in [arXiv:0706.3028].
description: 17 pages
Computational Investigations of Selected Enzymes From Two Iron and α-ketoglutarate-Dependent Families
Creators: name: Berger, Madison B.
name: Walker, Alice R.
name: Montelongo, Erik Antonio Vázquez
name: Cisneros, G. Andrés
Publisher: name: arXiv
Year: 2021
Subjects: subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: DNA alkylation is used as the key epigenetic mark in eukaryotes, however, most alkylation in DNA can result in deleterious effects. Therefore, this process needs to be tightly regulated. AlkB and TET are families within the Fe and $α$-kg-dependent superfamily of enzymes that are tasked with dealkylating DNA and RNA in cells. Members of these families span all species and are an integral part of transcriptional regulation. While both families catalyze oxidative dealkylation of various bases, each has specific preference for alkylated base type as well as distinct catalytic mechanisms. This perspective aims to provide an overview of computational work carried out to investigate several members of these enzyme families including AlkB, ALKBH2, ALKBH3 and TET2. Insights into structural details, mutagenesis studies, reaction path analysis, electronic structure features in the active site, and substrate preferences are presented and discussed
การพัฒนาบทเรียนคอมพิวเตอร์ช่วยสอนระบบมัลติมีเดียวิชาคณิตศษสตร์ เรื่อง พื้นฐานทางเรขาคณิต ชั้นมัธยมศึกษาปีที่ 1 โรงเรียนพรเจริญวิทยา
Creators: name: สุรส เนื่องชมภู
name: สมทรง สุวพานิช
name: อุดร อรกุล
name: ภูษิต บุญทองเถิง
Publisher: name: มหาวิทยาลัยราชภัฏมหาสารคาม
Year: 2007
Subjects: บทเรียนคอมพิวเตอร์ช่วยสอนระบบมัลติมีเดีย, คณิตศษสตร์, พื้นฐานทางเรขาคณิต, ชั้นมัธยมศึกษาปีที่ 1

description: 2, 1, วารสารมหาวิทยาลัยราชภัฏมหาสารคามมนุษยศาสตร์และสังคมศาสตร์
On Modelling a Relativistic Hierarchical (Fractal) Cosmology by Tolman's Spacetime. I. Theory
Creators: name: Ribeiro, Marcelo B.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: This work examines a relativistic model for the observed inhomogeneities of the large scale structure where the hypothesis that this structure can be described as being a self-similar fractal system is advanced. The concept of hierarchical clustering is identified with a fractal distribution and the problems raised by the use of fractal ideas in a relativistic model are discussed, as well as their relations to the Copernican and Cosmological Principles. Voids, clusters and superclusters of galaxies are assumed to be part of a smoothed-out fractal structure described by a Lemaitre-Tolman solution. The basic concepts of the Newtonian model presented by Pietronero (1987) are reinterpreted and applied to this inhomogeneous curved spacetime. This fractal system is also assumed to have a crossover to homogeneity which leads to a "Swiss cheese" type model, composed by an interior Lemaitre-Tolman metric and an exterior dust Friedmann solution. The Darmois junction conditions between the two spacetimes are calculated, and the observational relations necessary to compare the model with observations are obtained for the interior region. The differential equations of the interior spacetime are set up and a numerical strategy is devised for finding particular Tolman solutions representing a fractal behaviour along the past light cone.
description: 22 pages. LaTeX. Paper published in 1992
Slavistische Studien zum XI. Internationalen Slavistenkongreß in Preßburg/Bratislava
Creators: name: Schaller, Helmut Wilhelm
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 1997

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 46 Nr. 2 (1997)
Perfect fluid warp drive solutions with the cosmological constant
Creators: name: Santos-Pereira, Osvaldo L.
name: Abreu, Everton M. C.
name: Ribeiro, Marcelo B.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The Alcubierre metric describes a spacetime geometry that allows a massive particle inside a spacetime distortion, called warp bubble, to travel with superluminal global velocities. In this work we advance solutions of the Einstein equations with the cosmological constant for the Alcubierre warp drive metric having the perfect fluid as source. We also consider the particular dust case with the cosmological constant, which generalizes our previous dust solution (arXiv:2008.06560) and led to vacuum solutions connecting the warp drive with shock waves via the Burgers equation, as well as our perfect fluid solution without the cosmological constant (arXiv:2101.11467). All energy conditions are also analyzed. The results show that the shift vector in the direction of the warp bubble motion creates a coupling in the Einstein equations that requires off-diagonal terms in the energy-momentum source. Therefore, it seems that to achieve superluminal speeds by means of the Alcubierre warp drive spacetime geometry one may require a complex configuration and distribution of energy, matter and momentum as source in order to produce a warp drive bubble. In addition, warp speeds seem to require more complex forms of matter than dust for stable solutions and that negative matter may not be a strict requirement to achieve global superluminal speeds.
description: 15 pages, LaTeX. Accepted for publication in The European Physical Journal Plus. arXiv admin note: text overlap with arXiv:2101.11467
Secondary school art education : the artist’s viewpoint
Creators: name: Ewing, Gillian
Publisher: name: University of British Columbia
Year: 2010

description: Artists are seldom consulted in the making of school art programs yet many are vitally concerned with the need for a visually literate public. This study summarizes the history of art education, examines recent issues documented by art educators, looks at opinions of artists of this century on the teaching of art, and presents interviews with six British Columbian artists to elicit their thoughts on what is necessary in a secondary school art curriculum. The interviews are essentially informal in nature and only those remarks dealing with secondary school education, or related concepts, are included. The final chapter contains an infusion of the artists' ideas under headings suggested by issues raised by art educators. An evaluation of the data collected from the interviews leads to recommendations for consideration for secondary school programs and the conviction that artists should be encouraged to participate in matters relating to art education.
Quasi-binarity of massive stars in young dense clusters - the case of the ONC
Creators: name: Pfalzner, S.
name: Olczak, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Observations indicate that in young stellar clusters the binary fraction for massive stars is higher than for solar mass stars. For the Orion Nebula Cluster (ONC) there is a binary frequency of ~ 50% for solar-mass stars compared to 70-100% for the massive O- and B-stars. We explore the reasons for this discrepancy and come up with two possible answers: a) a primordially higher binarity of massive stars could be inherent to the star formation process or b) the primordial binary rate might be the same for solar-mass and massive stars, but the higher capture cross section of the massive stars possibly leads to the formation of additional massive binaries in the early cluster development. Here we investigate the likelihood of the latter using the ONC as an example. N-body simulations are performed to track the capture events in an ONC-like cluster. We find that whereas low-mass stars rarely form bound systems through capture, the dynamics of the massive stars - especially in the first 0.5 Myrs - is dominated by a rapid succession of ``transient binary or multiple systems''. In observations the transient nature of these systems would not be apparent, so that they would be rated as binaries. At 1-2 Myrs, the supposed age of the ONC, the ``transient'' massive systems become increasingly stable, lasting on average several 10^6 yrs. Despite the ONC being so young, the observed binary frequency for massive stars -- unlike that of solar-mass stars -- is not identical to the primordial binary frequency but is increased by at least 10-15% through dynamical interaction processes. This value might be increased to at least 20-25% by taking disc effects into account. The primordial binary frequency could well be the same for massive and solar mass stars because the observed difference can be explained by capture processes alone.
description: 9 pages, 7 figures. accepted by A&A
Magneto-hydrodynamic simulations of young supernova remnants and their energy-conversion phase
Creators: name: Petruk, O.
name: Kuzyo, T.
name: Orlando, S.
name: Pohl, M.
name: Brose, R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Supernova remnants (SNRs) can be rich sources of information on the parent SN explosion. Thus investigating the transition from the phase of SN to that of SNR can be crucial to link these two phases of evolution. Here we aim to study the early development of SNR in more details, paying the major attention to the transition from the early-expansion stage to the Sedov stage and the role played by magnetic field in this transition. To this end, spherical magneto-hydrodynamic simulations of SNRs have been performed to study the evolution of magnetic field in young SNRs and explore a sequence of the SNR evolutionary stages in the pre-radiative epoch. Remnants of three supernova types are considered, namely, SNIa, SNIc and SNIIP, that covers a wide space of parameters relevant for SNRs. Changes in global characteristics and development of spatial distributions are analysed. It is shown that the radial component of magnetic field rapidly drops downstream of the forward shock. Therefore, the radially-aligned polarization patterns observed in few young SNRs cannot be reproduced in the one-dimensional MHD simulations. The period SNR takes for the transition from the earliest ejecta-driven phase to the Sedov phase is long enough, with its distinctive physical features, headed by the energy conversion from mostly kinetic one to a fixed ratio between the thermal and kinetic components. This transition worth to be distinguished as a phase in SNR evolutionary scheme. The updated sequence of stages in SNR evolution could be the free expansion (of gas) -- energy-conversion -- Sedov-Taylor -- post-adiabatic -- radiative.
description: Accepted by MNRAS
Asymptotic behavior of permutation records
Creators: name: Kortchemski, Igor
Publisher: name: arXiv
Year: 2008
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: We study the asymptotic behavior of two statistics defined on the symmetric group S_n when n tends to infinity: the number of elements of S_n having k records, and the number of elements of S_n for which the sum of the positions of their records is k. We use a probabilistic argument to show that the scaled asymptotic behavior of these statistics can be described by remarkably simple functions.
description: 15 pages, 3 figures. v3: final version, to appear in Journal of Combinatorial Theory, Series A
Equisingularite reelle : invariants locaux et conditions de regularite
Creators: name: Comte, Georges
name: Merle, Michel
Publisher: name: arXiv
Year: 2007
Subjects: subject: Differential Geometry (math.DG)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 32C05, 32C18, 58K65

description: For germs of subanalytic sets, we define two finite sequences of new numerical invariants. The first one is obtained by localizing the classical Lipschitz-Killing curvatures, the second one is the real analogue of the evanescent characteristics introduced by M. Kashiwara. We show that each invariant of one sequence is a linear combination of the invariants of the other sequence. We then connect our invariants to the geometry of the discriminants of all dimension. Finally we prove that these invariants are continuous along Verdier strata of a closed subanalytic set.
description: 49 pages, 1 figure
Meta-stable Supersymmetry Breaking in an N=1 Perturbed Seiberg-Witten Theory
Creators: name: Sasaki, Shin
name: Arai, Masato
name: Montonen, Claus
name: Okada, Nobuchika
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this contribution, we discuss the possibility of meta-stable supersymmetry (SUSY) breaking vacua in a perturbed Seiberg-Witten theory with Fayet-Iliopoulos (FI) term. We found meta-stable SUSY breaking vacua at the degenerated dyon and monopole singular points in the moduli space at the nonperturbative level.
description: Submitted for the SUSY08 proceedings, 3 pages, 4 figures, references added, minor changes
Superconductivity and charge-density wave formation in lithium intercalated 2H-LixTaS2
Creators: name: Liu, Huanlong
name: Huangfu, Shangxiong
name: Zhang, Xiaofu
name: Lin, Hai
name: Schilling, Andreas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We systematically investigated the superconducting properties and the interplay between charge-density-waves (CDW) and superconductivity in lithium-intercalated 2H-TaS2. By gradually increasing the lithium content x, the CDW formation temperature is continuously suppressed, and the onset temperature of superconductivity is increased with a maximum transition temperature Tc = 3.5 K for x = 0.096. The bulk nature of superconductivity is confirmed by a superconducting shielding fraction of the order of unity for this composition. The electronic contribution to the specific heat and Hall resistivity data demonstrate that the CDW weakens with lithium-intercalation, thereby indirectly increasing carrier density and boosting superconductivity. While the sign of the charge carriers in undoped 2H-TaS2 changes from electron-like to hole type near the CDW formation temperature around 75 K, the lithium intercalated LixTaS2 show predominantly hole-type carriers in the CDW phase even for very low lithium contents.
description: 16 pages, 5 figures
Nation, Volk, Minderheit, Volksgruppe: Die deutsche Minderheit in Ungarn in den Begriffskämpfen der Zwischenkriegsära
Creators: name: Swanson, John C.
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 2006

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 55 Nr. 4 (2006)
Directed flow as effect of transient matter rotation in hadron and nucleus collisions
Creators: name: Troshin, S. M.
name: Tyurin, N. E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss directed flow introduced for description of nucleus collisions and consider its possible behavior in hadronic and nuclei reactions due to rotation of the transient matter.
description: 18 pages, 6 figures
Electroexcitation of the Roper resonance for 1.7 < Q2 < 4.5 GeV2 in ep -> enpi+
Creators: name: Aznauryan, I. G.
name: Burkert, V. D.
name: Kim, W.
name: Park, K.
name: collaboration, the CLAS
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The helicity amplitudes of the electroexcitation of the Roper resonance are extracted for 1.7 < Q2 < 4.5 GeV2 from recent high precision JLab-CLAS cross section and longitudinally polarized beam asymmetry data for pi+ electroproduction on protons at W=1.15-1.69 GeV. The analysis is made using two approaches, dispersion relations and a unitary isobar model, which give consistent results. It is found that the transverse helicity amplitude A_{1/2} for the gamma* p -> N(1440)P11 transition, which is large and negative at Q2=0, becomes large and positive at Q2 ~ 2 GeV2, and then drops slowly with Q2. The longitudinal helicity amplitude S_{1/2}, which was previously found from CLAS ep -> eppi0,enpi+ data to be large and positive at Q2=0.4,0.65 GeV2, drops with Q2. Available model predictions for gamma* p -> N(1440)P11 allow us to conclude that these results provide strong evidence in favor of N(1440)P11 as a first radial excitation of the 3q ground state. The results of the present paper also confirm the conclusion of our previous analysis for Q2 < 1 GeV2 that the presentation of N(1440)P11 as a 3qG hybrid state is ruled out.
description: 6 pages, 2 figures
Functions and signaling mechanisms of the membrane androgen receptor ZIP9 in Atlantic croaker (Micropogonias undulatus) and zebrafish (Danio rerio) ovaries
Creators: name: Converse, Aubrey Koch
name: 0000-0002-4203-1687
Publisher: name: The University of Texas at Austin
Year: 2019
Subjects: ZIP9
Ovary
Atlantic croaker
Zebrafish
Micropogonias undulates
Danio rerio

description: The overall goal of this research was to further characterize and verify the role of ZIP9 in mediating androgen-induced apoptosis of teleost granulosa/theca (G/T) cell co-culture. In addition, a global ZIP9 knockout zebrafish model was used to infer other roles of the receptor in the ovary, in vivo. While ZIP9 was first identified and found to mediate apoptosis of croaker G/T cells, little was known on the signaling mechanism mediated by the receptor. Therefore, stimulatory G protein alpha subunit-mediated signaling, MAP kinase (MAPK) activity, and the role of extracellular zinc were investigated in ZIP9-mediated apoptosis of croaker G/T cells. Additionally, the role of ZIP9 in mediation of testosterone-induced anti-apoptotic response observed in croaker G/T cells from fish outside of the reproductive peak was examined. To determine if ZIP9 mediates androgen-induced apoptosis in G/T cells of other teleosts, a zebrafish primary G/T culture system was used to examine androgen-mediated events. Finally, a global ZIP9 knockout zebrafish strain was developed to examine the effects of global ZIP9 knockout on female reproduction. The ZIP9-mediated apoptotic pathway in croaker G/T cells was found to require stimulatory G protein signaling and MAPK activity. Additionally, extracellular zinc is essential for the induction of ZIP9-mediated apoptosis in this model, and downstream responses to these signaling cascades include increased mRNA expression of pro-apoptotic protein members and caspase 3 activity. Pro- and anti-apoptotic effects of testosterone on croaker G/T cells was confirmed, and both responses were found to be mediated by ZIP9 in an ovarian follicle stage-dependent manner. ZIP9 activation of stimulatory and inhibitory G proteins elicits the pro- and anti-apoptotic responses, respectively. In pooled zebrafish G/T cells, testosterone treatment results in an increased incidence of apoptosis, caspase 3 activity, upregulation of pro-apoptotic protein member mRNA, and a rapid rise in intracellular free zinc. This testosterone-mediated response was attributed to ZIP9 activity, thus, ZIP9 mediates apoptosis through a similar mechanism in zebrafish G/T cells as observed in croaker. Finally, examination of ZIP9 global knockout zebrafish demonstrated that ZIP9 mutation results in reduced fecundity and abnormal egg phenotypes, even though no abnormalities in ovarian morphology were apparent through histological examination.
Dieter Blumenwitz, Das Offenhalten der Vermögensfrage in den deutsch-polnischen Beziehungen
Creators: name: Westen, Klaus
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 1997

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 46 Nr. 2 (1997)
Raychaudhuri equations and gravitational collapse in Einstein-Cartan theory
Creators: name: Hensh, Sudipta
name: Liberati, Stefano
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The Raychaudhuri equations for the expansion, shear and vorticity are generalized in a spacetime with torsion for timelike as well as null congruences. These equations are purely geometrical like the original Raychaudhuri equations and could be reduced to them when there is no torsion. Using the Einstein-Cartan-Sciama-Kibble field equations the effective stress-energy tensor is derived. We also consider an Oppenheimer-Snyder model for the gravitational collapse of dust. It is shown that the null energy condition (NEC) is violated before the density of the collapsing dust reaches the Planck density, hinting that the spacetime singularity may be avoided if there is a non-zero torsion,i.e. if the collapsing dust particles possess intrinsic spin.
Die Innovationsbereitschaft der livländischen Bauern und die Agrarreformen im 19. Jahrhundert
Creators: name: Lust, Kersti
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 2006

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 55 Nr. 4 (2006)
Drei Predigten des Kardinals Odo von Châteauroux über Hedwig von Schlesien. Wandlungen und Kontinuitäten im Heiligenideal des 13. Jahrhunderts
Creators: name: Krafft, Otfried
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 2006

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 55 Nr. 4 (2006)
Is flare-ribbon fine structure related to tearing in the flare current sheet?
Creators: name: Wyper, P. F.
name: Pontin, D. I.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Observations of solar flare ribbons show significant fine structure in the form of breaking wave-like perturbations and spirals. The origin of this structure is not well understood, but one possibility is that it is related to the tearing instability in the flare current sheet. Here we study this connection by constructing an analytical three-dimensional magnetic field representative of an erupting flux rope with a flare current sheet below it. We introduce small-scale flux ropes representative of those formed during a tearing instability in the current layer, and use the squashing factor on the solar surface to identify the shape of the presumed flare ribbons and fine structure. Our analysis suggests there is a direct link between flare-ribbon fine structure and flare current sheet tearing, with the majority of the ribbon fine structure related to oblique tearing modes. Depending upon the size, location and twist of the small-scale flux ropes, breaking wave-like and spiral features within the hooks and straight sections of the flare ribbon can be formed that are qualitatively similar to observations. We also show that the handedness of the spirals/waves must be the same as the handedness of the hooks of the main ribbon. We conclude that tearing in the flare current layer is a likely explanation for spirals and wave-like features in flare ribbons.
description: ApJ, in press, 16 pages, 14 figures
Tuning magnetic and optical properties through strain in epitaxial LaCrO3 thin films
Creators: name: Sharma, Yogesh
name: Paudel, Binod
name: Lee, Jegon
name: Choi, Woo Seok
name: Yang, Zhenzhong
name: Wang, Han
name: Du, Yingge
name: Kang, Kyeong Tae
name: Pilania, Ghanshyam
name: Chen, Aiping
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report on the effect of epitaxial strain on magnetic and optical properties of perovskite LaCrO3 (LCO) single crystal thin films. Epitaxial LCO thin films are grown by pulsed laser deposition on proper choice of substrates to impose different strain states. A combined experimental and theoretical approach is used to demonstrate the direct correlation between lattice-strain and functional properties. The magnetization results show that the lattice anisotropy plays a critical role in controlling the magnetic behavior of LCO films. The strain induced tetragonality in the film lattice strongly affects the optical transitions and charge transfer gap in LCO. This study opens new possibilities to tailoring the functional properties of LCO and related materials by strain engineering in epitaxial growth.
Practical reasoning and teacher education
Creators: name: La Bar, Caroline Mary
Publisher: name: University of British Columbia
Year: 2010

description: In this thesis it is argued that the constituents of practical reasoning are necessary for good teaching; as such, the study of practical reasoning would be a valuable addition to teacher education programs. Practical reasoning is basically reasoning about what should be done. In Chapter II a conception of practical reasoning developed by Jerrold Coombs is outlined. This conception, which includes a variety of abilities, dispositions and sensitivities, as well as knowledge about a number of concepts and distinctions, is used throughout chapters III and IV to illustrate its value in typical teaching activities. These typical teaching activities are divided into two categories, using a distinction conceived by Thomas Green. Green has described teaching as a "practical activity" which consists of perhaps hundreds of single different activies. He divides these activities into three categories: 1) logical acts (for example, explaining, concluding, inferring, giving reasons); 2) strategic acts (motivating, planning, evaluating, disciplining); and 3) institutional acts (taking attendance, keeping reports, consulting parents). Institutional acts, he says, are not necessary to the activity of teaching. However, both logical and strategic acts are "...indispensable to the conduct of teaching wherever and whenever it is found (Green, 1975, p. 5). Furthermore, he argues that "Teaching can be improved by improving either kind of activity, but it cannot be excellent without attention to both (ibid., p. 8)." In Chapter III, I have illustrated how practical reasoning would improve the logical acts of teaching and in Chapter IV I have argued that practical reasoning would improve the strategic acts. Chapter V includes a summary of the major argument and concludes with some suggestions about how to develop teachers practical reasoning abilities and dispositions.
Efficient stochastic sampling of first-passage times with applications to self-assembly simulations
Creators: name: Misra, Navodit
name: Schwartz, Russell
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: FOS: Biological sciences

description: Models of reaction chemistry based on the stochastic simulation algorithm (SSA) have become a crucial tool for simulating complicated biological reaction networks due to their ability to handle extremely complicated reaction networks and to represent noise in small-scale chemistry. These methods can, however, become highly inefficient for stiff reaction systems, those in which different reaction channels operate on widely varying time scales. In this paper, we develop two methods for accelerating sampling in SSA models: an exact method and a scheme allowing for sampling accuracy up to any arbitrary error bound. Both methods depend on analysis of the eigenvalues of continuous time Markov model graphs that define the behavior of the SSA. We demonstrate these methods for the specific application of sampling breakage times for multiply-connected bond networks, a class of stiff system important to models of self-assembly processes. We show theoretically and empirically that our eigenvalue methods provide substantially reduced sampling times for a wide range of network breakage models. These techniques are also likely to have broad use in accelerating SSA models so as to apply them to systems and parameter ranges that are currently computationally intractable.
description: 40 pages, 15 figures
Thomas DaCosta Kaufmann, Court, Cloister and City. The Art and Culture of Central Europe 1450-1800
Creators: name: Lambrecht, Karen
Publisher: name: Zeitschrift für Ostmitteleuropa-Forschung
Year: 1997

description: Zeitschrift für Ostmitteleuropa-Forschung, Bd. 46 Nr. 2 (1997)