cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Extremal Sasakian Geometry on S^3-bundles over Riemann Surfaces
Creators: name: Boyer, Charles P.
name: Tønnesen-Friedman, Christina W.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Differential Geometry (math.DG)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics
subject: Primary: 53D42, Secondary: 53C25

description: In this paper we study the Sasakian geometry on S^3-bundles over a Riemann surface of genus g>0 with emphasis on extremal Sasaki metrics. We prove the existence of a countably infinite number of inequivalent contact structures on the total space of such bundles that admit 2-dimensional Sasaki cones each with a Sasaki metric of constant scalar curvature (CSC). This CSC Sasaki metric is most often irregular. We further study the extremal subset in the Sasaki cone showing that if 0
description: 52 pages
Continuous Data Assimilation Using General Interpolant Observables
Creators: name: Azouani, Abderrahim
name: Olson, Eric
name: Titi, Edriss S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Analysis of PDEs (math.AP)
subject: Chaotic Dynamics (nlin.CD)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 35Q30, 93C20, 37C50, 76B75, 34D06

description: We present a new continuous data assimilation algorithm based on ideas that have been developed for designing finite-dimensional feedback controls for dissipative dynamical systems, in particular, in the context of the incompressible two-dimensional Navier--Stokes equations. These ideas are motivated by the fact that dissipative dynamical systems possess finite numbers of determining parameters (degrees of freedom) such as modes, nodes and local spatial averages which govern their long-term behavior. Therefore, our algorithm allows the use of any type of measurement data for which a general type of approximation interpolation operator exists. Our main result provides conditions, on the finite-dimensional spatial resolution of the collected data, sufficient to guarantee that the approximating solution, obtained by our algorithm from the measurement data, converges to the unknown reference solution over time. Our algorithm is also applicable in the context of signal synchronization in which one can recover, asymptotically in time, the solution (signal) of the underlying dissipative system that is corresponding to a continuously transmitted partial data.
Valid post-selection inference
Creators: name: Berk, Richard
name: Brown, Lawrence
name: Buja, Andreas
name: Zhang, Kai
name: Zhao, Linda
Publisher: name: arXiv
Year: 2013
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: It is common practice in statistical data analysis to perform data-driven variable selection and derive statistical inference from the resulting model. Such inference enjoys none of the guarantees that classical statistical theory provides for tests and confidence intervals when the model has been chosen a priori. We propose to produce valid ``post-selection inference'' by reducing the problem to one of simultaneous inference and hence suitably widening conventional confidence and retention intervals. Simultaneity is required for all linear functions that arise as coefficient estimates in all submodels. By purchasing ``simultaneity insurance'' for all possible submodels, the resulting post-selection inference is rendered universally valid under all possible model selection procedures. This inference is therefore generally conservative for particular selection procedures, but it is always less conservative than full Scheffe protection. Importantly it does not depend on the truth of the selected submodel, and hence it produces valid inference even in wrong models. We describe the structure of the simultaneous inference problem and give some asymptotic results.
description: Published in at http://dx.doi.org/10.1214/12-AOS1077 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Compressed Sensing under Matrix Uncertainty: Optimum Thresholds and Robust Approximate Message Passing
Creators: name: Krzakala, Florent
name: Mézard, Marc
name: Zdeborová, Lenka
Publisher: name: arXiv
Year: 2013
Subjects: subject: Information Theory (cs.IT)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In compressed sensing one measures sparse signals directly in a compressed form via a linear transform and then reconstructs the original signal. However, it is often the case that the linear transform itself is known only approximately, a situation called matrix uncertainty, and that the measurement process is noisy. Here we present two contributions to this problem: first, we use the replica method to determine the mean-squared error of the Bayes-optimal reconstruction of sparse signals under matrix uncertainty. Second, we consider a robust variant of the approximate message passing algorithm and demonstrate numerically that in the limit of large systems, this algorithm matches the optimal performance in a large region of parameters.
description: 5 pages, 4 figures
EFFICIENCY OF PUBLIC-PRIVATE PARTNERSHIP  IN THE WATER SECTOR
Creators: name: Alibekova, N.N.
Publisher: name: Zenodo
Year: 2023

description: Today, the problem of water resources and their efficient use is topical in many countries of the world. Due to the geographical features of the country, this problem has a serious impact on the economy of the country. The Decree of the President of the Republic of Uzbekistan dated November 30, 2018 № PP-4040 "On additional measures for the development of drinking water supply and sanitation systems in the Republic of Uzbekistan" was published.
Stationary two-dimensional turbulence statistics using a Markovian forcing scheme
Creators: name: San, Omer
name: Staples, Anne E.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In this study we investigate the statistics of two-dimensional stationary turbulence using a Markovian forcing scheme, which correlates the forcing process in the current time step to the previous time step according to a defined memory coefficient. In addition to the Markovian forcing mechanism, the hyperviscous dissipation mechanism for small scales and the Ekman friction type of linear damping mechanism for the large scales are included in the model. We examine the effects of various dissipation and forcing parameters on the turbulence statistics in both wave space and physical space. Our analysis includes the effects of the effective forcing scale, the bandwidth of the forcing, the memory correlation coefficient, and the forcing amplitude, along with the large scale friction and small scale dissipation coefficients. Scaling exponents of structure functions and energy spectra are calculated, and the role of the parameters associated with the Markovian forcing is discussed. We found that the scaling exponents are approximately invariant and show a universal behavior for the various forms of forcing schemes used. We found, however, that the final states strongly depend on the large scale friction mechanism considered. When the large scale friction mechanism is included in the model with a high friction coefficient, we demonstrate that the behavior is no longer universal. Our analysis also shows that the second-order vorticity structure function has an asymptotic scaling exponent for larger dissipation. Additionally, we confirmed that vorticity behaves as a passive scalar when the dissipation mechanism becomes less effective. Finally, although turbulence is not believed to have a separation of time scales in the dynamics of the velocity field, we conjectured that a separation of time scales exists in the dynamics of the energy spectrum.
Collisionless shocks in partly ionized plasma with cosmic rays: microphysics of non-thermal components
Creators: name: Bykov, A. M.
name: Malkov, M. A.
name: Raymond, J. C.
name: Krassilchtchikov, A. M.
name: Vladimirov, A. E.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In this review we discuss some observational aspects and theoretical models of astrophysical collisionless shocks in partly ionized plasma with the presence of non-thermal components. A specific feature of fast strong collisionless shocks is their ability to accelerate energetic particles that can modify the shock upstream flow and form the shock precursors. We discuss the effects of energetic particle acceleration and associated magnetic field amplification and decay in the extended shock precursors on the line and continuum multi-wavelength emission spectra of the shocks. Both Balmer-type and radiative astrophysical shocks are discussed in connection to supernova remnants interacting with partially neutral clouds. Quantitative models described in the review predict a number of observable line-like emission features that can be used to reveal the physical state of the matter in the shock precursors and the character of nonthermal processes in the shocks. Implications of recent progress of gamma-ray observations of supernova remnants in molecular clouds are highlighted.
description: 38 pages, 10 figures, Space Science Reviews (to be published)
Precision measurements of the Planck and Avogadro constants
Creators: name: Bettin, Horst
name: Fujii, Kenichi
name: Man, John
name: Mana, Giovanni
name: Massa, Enrico
name: Picard, Alain
Publisher: name: arXiv
Year: 2013
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Precision measurements of the fundamental constants are tour de force of basic metrology, where the useful information is usually beyond the last digit of the measured value. They challenge theoretical models and measurement technologies and set a network of measurement equations on which a universal system of units can be built, which stems from the most basic concepts of physics. Because of their connection with the mass unit, the Avogadro and Planck constants are on the spotlight.
description: 12 pages, 2 figures, submitted to Annalen der Physiks
High-order methods for decaying two-dimensional homogeneous isotropic turbulence
Creators: name: San, Omer
name: Staples, Anne E.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Numerical schemes used for the integration of complex flow simulations should provide accurate solutions for the long time integrations these flows require. To this end, the performance of various high-order accurate numerical schemes is investigated for direct numerical simulations (DNS) of homogeneous isotropic two-dimensional decaying turbulent flows. The numerical accuracy of compact difference, explicit central difference, Arakawa, and dispersion-relation-preserving schemes are analyzed and compared with the Fourier-Galerkin pseudospectral scheme. In addition, several explicit Runge-Kutta schemes for time integration are investigated. We demonstrate that the centered schemes suffer from spurious Nyquist signals that are generated almost instantaneously and propagate into much of the field when the numerical resolution is insufficient. We further show that the order of the scheme becomes increasingly important for increasing cell Reynolds number. Surprisingly, the sixth-order schemes are found to be in perfect agreement with the pseudospectral method. Considerable reduction in computational time compared to the pseudospectral method is also reported in favor of the finite difference schemes. Among the fourth-order schemes, the compact scheme provides better accuracy than the others for fully resolved computations. The fourth-order Arakawa scheme provides more accurate results for under-resolved computations, however, due to its conservation properties. Our results show that, contrary to conventional wisdom, difference methods demonstrate superior performance in terms of accuracy and efficiency for fully resolved DNS computations of the complex flows considered here. For under-resolved simulations, however, the choice of difference method should be made with care.
Vacuum-assisted generation and control of atomic coherences at x-ray energies
Creators: name: Heeg, Kilian P.
name: Wille, Hans-Christian
name: Schlage, Kai
name: Guryeva, Tatyana
name: Schumacher, Daniel
name: Uschmann, Ingo
name: Schulze, Kai S.
name: Marx, Berit
name: Kämpfer, Tino
name: Paulus, Gerhard G.
name: Röhlsberger, Ralf
name: Evers, Jörg
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: The control of light-matter interaction at the quantum level usually requires coherent laser fields. But already an exchange of virtual photons with the electromagnetic vacuum field alone can lead to quantum coherences, which subsequently suppress spontaneous emission. We demonstrate such spontaneously generated coherences (SGC) in a large ensemble of nuclei operating in the x-ray regime, resonantly coupled to a common cavity environment. The observed SGC originates from two fundamentally different mechanisms related to cooperative emission and magnetically controlled anisotropy of the cavity vacuum. This approach opens new perspectives for quantum control, quantum state engineering and simulation of quantum many-body physics in an essentially decoherence-free setting.
description: 5 pages, 3 figures
Results of magnetic field measurements in young stars DO Tau, DR Tau, DS Tau
Creators: name: Dodin, A. V.
name: Lamzin, S. A.
name: Chountonov, G. A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Results of measurements of the longitudinal magnetic field in a hot accretion spot in three classical T Tauri stars (CTTS) are presented. The magnetic field in the formation region of the narrow component of the emission line HeI 5876 Å was found for each star in our sample at a level of more than 2σ. In case of DS Tau we have found the field in the narrow components of NaI D lines, which was equal to +0.8 \pm 0.3 kG, i.e. it was equal to the field measured on the narrow component of HeI 5876 Å. Our results indicate that the magnetic field in the hot spots can be studied for CTTS down to 13^m that allow in the future to double a number of CTTS with measured field in the accretion zone.
description: 12 pages, 2 figures, accepted for publication in Astrophysical Bulletin
A coarse-grid projection method for accelerating incompressible flow computations
Creators: name: San, Omer
name: Staples, Anne E.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We present a coarse-grid projection (CGP) method for accelerating incompressible flow computations, which is applicable to methods involving Poisson equations as incompressibility constraints. The CGP methodology is a modular approach that facilitates data transfer with simple interpolations and uses black-box solvers for the Poisson and advection-diffusion equations in the flow solver. After solving the Poisson equation on a coarsened grid, an interpolation scheme is used to obtain the fine data for subsequent time stepping on the full grid. A particular version of the method is applied here to the vorticity-stream function, primitive variable, and vorticity-velocity formulations of incompressible Navier-Stokes equations. We compute several benchmark flow problems on two-dimensional Cartesian and non-Cartesian grids, as well as a three-dimensional flow problem. The method is found to accelerate these computations while retaining a level of accuracy close to that of the fine resolution field, which is significantly better than the accuracy obtained for a similar computation performed solely using a coarse grid. A linear acceleration rate is obtained for all the cases we consider due to the linear-cost elliptic Poisson solver used, with reduction factors in computational time between 2 and 42. The computational savings are larger when a suboptimal Poisson solver is used. We also find that the computational savings increase with increasing distortion ratio on non-Cartesian grids, making the CGP method a useful tool for accelerating generalized curvilinear incompressible flow solvers.
An Outlook on Nuclear Physics
Creators: name: Balantekin, A. B.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: A brief outlook on low-energy nuclear physics is presented. Selected recent developments in nuclear structure theory are highlighted and a few open questions are discussed.
description: Presented at the Zakopane School on Nuclear Physics "Extremes of the Nuclear Landscape", August 27 - September 2, 2012, Zakopane, Poland
Chemical analysis of giant stars in the young open cluster NGC 3114
Creators: name: Santrich, O. J. Katime
name: Pereira, C. B.
name: Drake, N. A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context: Open clusters are very useful targets for examining possible trends in galactocentric distance and age, especially when young and old open clusters are compared. Aims: We carried out a detailed spectroscopic analysis to derive the chemical composition of seven red giants in the young open cluster NGC 3114. Abundances of C, N, O, Li, Na, Mg, Al, Ca, Si, Ti, Ni, Cr, Y, Zr, La, Ce, and Nd were obtained, as well as the carbon isotopic ratio. Methods: The atmospheric parameters of the studied stars and their chemical abundances were determined using high-resolution optical spectroscopy. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code MOOG. The abundances of the light elements were derived using the spectral synthesis technique. Results: We found that NGC 3114 has a mean metallicity of [Fe/H] = -0.01+/-0.03. The isochrone fit yielded a turn-off mass of 4.2 Msun. The [N/C] ratio is in good agreement with the models predicted by first dredge-up. We found that two stars, HD 87479 and HD 304864, have high rotational velocities of 15.0 km/s and 11.0 km/s; HD 87526 is a halo star and is not a member of NGC 3114. Conclusions: The carbon and nitrogen abundance in NGC 3114 agree with the field and cluster giants. The oxygen abundance in NGC 3114 is lower compared to the field giants. The [O/Fe] ratio is similar to the giants in young clusters. We detected sodium enrichment in the analyzed cluster giants. As far as the other elements are concerned, their [X/Fe] ratios follow the same trend seen in giants with the same metallicity.
description: 17 pages, 9 figures, 10 tables; accepted for publication in A&A
Svalbard Environment Monitoring System at UNIS
Creators: name: Sikora, Sebastian Dominik
Publisher: name: Zenodo
Year: 2023

description: The intensification of human impact on the environment has reached unprecedented levels, and nowhere is this more evident than in the Arctic. The repercussions of these processes are readily observed, emphasizing the urgent need for collecting environmental data through automated monitoring stations. Access to this information is crucial in order to comprehensively comprehend the ongoing changes. This is particularly significant due to the challenging conditions faced by human presence in the polar regions, where harsh environmental factors constantly necessitate adaptation to new circumstances. 
For three decades, scientists from The University Centre in Svalbard (UNIS) have been collecting Arctic environmental data. Throughout this period, numerous installations have been established, varying in their duration. While some installations have become more permanent fixtures, others may only endure for days, weeks, or even a single season. Weather data play a crucial role in both day-to-day activities and long-term perspectives. Recognizing their significance, researchers at the University Centre in Svalbard (UNIS) are actively working on expanding their network of automatic weather stations (AWS) in the region. These AWS units are designed to collect essential parameters such as air temperature, humidity, wind speed, and wind direction. Moreover, some stations are equipped with specialized devices like net radiometers, pyranometers installed at various angles, Eddy Covariance systems, methane probes, thermistor strings in bore holes, photosynthetic active radiation meters, icing detectors, and snow depth meters.
The first spectroscopically identified L dwarf in Praesepe
Creators: name: Boudreault, S.
name: Lodieu, N.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We have obtained a low-resolution optical spectrum for one of the faintest cluster member candidates in Praesepe with the Optical System for Imaging and low Resolution Integrated Spectroscopy mounted on the 10.4m Gran Telescopio de Canarias. We confirm spectroscopically the first L dwarf member in Praesepe, UGCS J084510.66+214817.1. We derived an optical spectral type of L0.3+/-0.4 and estimated its effective temperature to Teff=2279+/-371 K and a mass of 71.1+/-23.0M_Jup, according to state-of-the-art models, placing it at the hydrogen-burning boundary. We measured the equivalent width of the gravity-sensitive sodium doublet at 8182/8194 A, which adds credit to the membership of this new L dwarf to Praesepe. We also derived a probability of ~20.5% that our candidate would be a field L0 dwarf. We conclude that this object is likely to be a true member of Praesepe, with evidence of being a binary system.
description: 6 pages, 3 figures, accepted for publication in MNRAS
The importance of major mergers in the build up of stellar mass in brightest cluster galaxies at z=1
Creators: name: Lidman, C.
name: Iacobuta, G.
name: Bauer, A. E.
name: Barrientos, L. F.
name: Cerulo, P.
name: Couch, W. J.
name: Delaye, L.
name: Demarco, R.
name: Ellingson, E.
name: Faloon, A. J.
name: Gilbank, D.
name: Huertas-Company, M.
name: Mei, S.
name: Meyers, J.
name: Muzzin, A.
name: Noble, A.
name: Nantais, J.
name: Rettura, A.
name: Rosati, P.
name: Sanchez-Janssen, R.
name: Strazzullo, V.
name: Webb, T. M. A.
name: Wilson, G.
name: Yan, R.
name: Yee, H. K. C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Recent independent results from numerical simulations and observations have shown that brightest cluster galaxies (BCGs) have increased their stellar mass by a factor of almost two between z~0.9 and z~0.2. The numerical simulations further suggest that more than half this mass is accreted through major mergers. Using a sample of 18 distant galaxy clusters with over 600 spectroscopically confirmed cluster members between them, we search for observational evidence that major mergers do play a significant role. We find a major merger rate of 0.38 +/- 0.14 mergers per Gyr at z~1. While the uncertainties, which stem from the small size of our sample, are relatively large, our rate is consistent with the results that are derived from numerical simulations. If we assume that this rate continues to the present day and that half of the mass of the companion is accreted onto the BCG during these mergers, then we find that this rate can explain the growth in the stellar mass of the BCGs that is observed and predicted by simulations. Major mergers therefore appear to be playing an important role, perhaps even the dominant one, in the build up of stellar mass in these extraordinary galaxies.
description: 15 pages, 6 figures, accepted for publication in MNRAS. Reduced data will be made available through the ESO archive
Potential thermoelectric performance of hole-doped Cu2O
Creators: name: Chen, Xin
name: Parker, David
name: Du, Mao-Hua
name: Singh, David J.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: High thermoelectric performance in oxides requires stable conductive materials that have suitable band structures. Here we show based on an analysis of the thermopower and related properties using first-principles calculations and Boltzmann transport theory that hole doped Cu2O may be such a material. We find that hole-doped Cu2O has a high thermopower of above 200 microV/K even with doping levels as high as 5.5x10 20 cm-3 at 500 K, mainly attributed to the heavy valence bands of Cu2O. This is reminiscent of the cobaltate family of high performance oxide thermoelectrics and implies that hole-doped Cu2O could be an excellent thermoelectric material if suitably doped.
Temperature, gravity and bolometric correction scales for non-supergiant OB stars
Creators: name: Nieva, Maria-Fernanda
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. Precise and accurate determinations of effective temperature and surface gravity are mandatory to derive reliable chemical abundances and fundamental parameters like distances, masses, radii, luminosities of OB stars. Aims. Atmospheric parameters recently determined at high precision with several independent spectroscopic indicators in NLTE are employed to calibrate photometric relationships. Methods. Temperatures and gravities of 30 calibrators are compared to reddening-independent quantities of the Johnson and Stroemgren photometric systems. We also examine the spectral and luminosity classification of the star sample and compute bolometric corrections. Results. Calibrations of temperatures and gravities are proposed for various photometric indices and spectral types. Effective temperatures can be determined at a precision of ~400 K for luminosity classes III/IV and ~800 K for luminosity class V. Surface gravities can reach internal uncertainties as low as ~0.08 dex when using our calibration to the Johnson Q-parameter. Similar precision is achieved for gravities derived from the beta-index and the precision is lower for both atmospheric parameters when using the Stroemgren indices c1 and [u-b]. Our uncertainties are smaller than typical differences among other methods in the literature, reaching values up to ~2000 K for temperature and ~0.25 dex for gravity, and in extreme cases, ~6000 K and ~0.4 dex, respectively. A parameter calibration for sub-spectral types is also proposed. We present a new bolometric correction relation to temperature based on our empirical data. Conclusions. The photometric calibrations presented here are useful tools to estimate effective temperatures and surface gravities of non-supergiant OB stars in a fast manner. We recommend to use these calibrations as a first step, with subsequent refinements based on spectroscopy (abridged).
description: 14 pages, 11 figures, accepted to be published in A&A
Collective baryon decay and gravitational collapse
Creators: name: Chapline, George
name: Barbieri, James
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: While it is widely believed that the gravitational collapse of a sufficiently large mass will lead to a density singularity and an event horizon, we propose that this never happens when quantum effects are taken into account. In particular, we propose that when the conditions become ripe for a trapped surface to form, a quantum critical surface sweeps over the collapsing body, transforming the nucleons in the collapsing matter into a lepton/photon gas together with a positive vacuum energy. This will happen regardless of the matter density at the time a trapped surface starts to form, and as a result we predict that at least in all cases of gravitational collapse involving ordinary matter, a large fraction of the rest mass of the collapsing matter will be converted into a burst of neutrinos, and γ-rays. We predict that the peak luminosity of these bursts is only weakly dependent on the mass of the collapsing object, and is on the order of (ε_q/m_Pc^2)^1/4c^5/G, where ε_q is the mean energy of a nucleon parton and m_P is the Planck mass. The duration of the bursts will depend the mass of the collapsing objects; in the case of stellar core collapse we predict that the duration of both the neutrino and γ-ray bursts will be on the order of 10 seconds.
description: 19 pages, 2 figures
Wide Integral-Field Infrared Spectroscopy of the Bright [Fe II] Shell in the Young Supernova Remnant G11.2-0.3
Creators: name: Lee, Ho-Gyu
name: Moon, Dae-Sik
name: Koo, Bon-Chul
name: Rahman, Mubdi
name: Eikenberry, Stephen S.
name: Gruel, Nicolas
name: Onaka, Takashi
name: Kim, Hyun-Jeong
name: Chun, Won-Seok
name: Raymond, J. C.
name: Raines, S. Nicholas
name: Guzman, Rafael
Publisher: name: arXiv
Year: 2013
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the results of wide integral-field near-infrared (1.0-1.8 um) spectroscopic observations of the southeastern shell of the young core-collapse supernova remnant (SNR) G11.2-0.3. We first construct [Fe II] 1.644 um line images of three bright clumps from the obtained spectral image cubes and compare them with those of other transitions such as [Fe II] 1.257, [Fe II] 1.534 and He I 1.083 um line images. This allows us to estimate the electron density (~ 4,700-9,400 cm^-3) and extinction (Av ~ 16-20 mag) of the shell, including detailed two-dimensional distribution of the properties in the brightest clump, as well as the discovery of a faint high-velocity (~ -440 km/s) component in the clump. Our SNR shock model calculations estimate the preshock number density of ~ 250-500 cm^-3 and shock speed of ~ 80-250 km/s in the [Fe II]-emitting region of the SNR. The comparison between the observed and modelled radial profiles of the line intensities and their ratios reveals that the shell is composed of multiple thin filaments which have been likely formed in episodic mass loss processes of a progenitor star. The discovery of the faint high-velocity component supports the interpretation that the southeastern shell of G11.2-0.3 is mainly composed of circumstellar material with contamination by supernova ejecta and also that its ejected material was expelled primarily in the southeast-northwest direction.
description: 5 pages, 4 figures, 1 table; accepted for publication in ApJ
Ageing Well Talk Series 22/23 -Talk 2: Taking control of dying . Accessible document
Creators: name: Odunewu, Chrispina
Publisher: name: The Open University
Year: 2022
Subjects: Aged health care
Family care
General practice
Health and community services
Health care administration
Health counselling
Health informatics and information systems
Health management
Health services and systems not elsewhere classified
Health surveillance
Health systems
Implementation science and evaluation
Mental health services
Multimorbidity
Palliative care
Patient safety
Primary health care
Residential client care

description: Taking control of dying - Barbara Gale, - Ageing Well Series 22/23 - Berrill Stadium (open.ac.uk) October 19th 2022 In this talk, Barbara and Victoria will present on what are the things we don’t talk about & preparing for our death and as a relative preparing for someone else’s death. We will also talk about ways we can take some of the control over our dying and what are the ways we can co-create our care plans. Dr Barbara Gale, MBE - Visiting Senior Fellow in Integrated Care for the Integrated Care Academy (ICA). Barbara has 40 years’ experience working in end-of-life care, with a background in nursing, palliative care and systemic family therapy. Most recently Barbara was Chief Executive of St Nicholas Hospice Care from 2007 to 2021, developing innovative models of care, built on public health and asset-based community development approaches to palliative care. Dr Victoria Hedges - Victoria works as Consultant in Palliative Medicine, Oxford University Hospitals NHS Foundation Trust and also at Sobell House hospice in Oxford and provides specialist advice for patients in a broad range of settings (including in the community and hospitals). She also works with the Oxford Kidney Unit, providing supportive care for patients and their families who are making complex decisions, such as to stop haemodialysis.
Confirming the LHC Higgs Discovery with WW
Creators: name: Kao, Chung
name: Sayre, Joshua
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate the prospects of observing a neutral Higgs boson decaying into a pair of $W$ bosons (one real and the other virtual), followed by the $W$ decays into $qq' \ellν$ or $jj\ellν$ at the CERN Large Hadron Collider (LHC). Assuming that the missing transverse energy comes solely from the neutrino in $W$ decay, we can reconstruct the $W$ masses and then the Higgs mass. At the LHC with a center of mass energy ($\sqrt{s}$) of 8 TeV and an integrated luminosity ($L$) of 25 fb$^{-1}$, we can potentially establish a $6σ$ signal. A $5σ$ discovery of $H \to WW^* \to jj\ellν$ for $\sqrt{s} = 14$ TeV can be achieved with $L = $ 6 fb$^{-1}$. The discovery of $H \to WW$ implies that the recently discovered new boson is a CP-even scalar if its spin is zero. In addition, this channel will provide a good opportunity to study the $HWW$ coupling.
Decoupling Crossover in Asymmetric Broadside Coupled Split Ring Resonators at Terahertz Frequencies
Creators: name: Keiser, George R.
name: Strikwerda, Andrew C.
name: Fan, Kebin
name: Young, Valerie
name: Zhang, Xin
name: Averitt, Richard D.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We investigate the electromagnetic response of asymmetric broadside coupled split ring resonators (ABC-SRRs) as a function of the relative in-plane displacement between the two component SRRs. The asymmetry is defined as the difference in the capacitive gap widths (Δg) between the two resonators comprising a coupled unit. We characterize the response of ABC-SRRs both numerically and experimentally via terahertz time-domain spectroscopy. As with symmetric BC-SRRs (Δg=0 μm), a large redshift in the LC resonance is observed with increasing displacement, resulting from changes in the capacitive and inductive coupling. However, for ABC-SRRs, in-plane shifting between the two resonators by more than 0.375Lo (Lo=SRR sidelength) results in a transition to a response with two resonant modes, associated with decoupling in the ABC-SRRs. For increasing Δg, the decoupling transition begins at the same relative shift (0.375Lo), though with an increase in the oscillator strength of the new mode. This strongly contrasts with symmetric BC-SRRs which present only one resonance for shifts up to 0.75Lo. Since all BC-SRRs are effectively asymmetric when placed on a substrate, an understanding of ABC-SRR behavior is essential for a complete understanding of BC-SRR based metamaterials.
title: Fabrication and imaging of oxidation-free phosphorene
Creators: name: Lamprecht, David
Year: 2023

description: Schwarzer Phosphor (Phosphoren) ist ein Material aus der Klasse der niedrigdimensionalen Materialien, welches aufgrund der anisotropen Struktur und guter elektronischen, optischen und mechanischen Materialeigenschaften als zukunftsträchtiger Werkstoff für elektronische und opto-elektronische Anwendungen gilt. In der Praxis ist die Anwendbarkeit von Phosphoren jedoch durch bedingte Umweltstabilität stark eingeschränkt. Um Schutzmechanismen gegen Umwelteinflüsse zu entwickeln, müssen die Mechanismen dieser Instabilität bis auf atomarer Größenordnung untersucht werden. In dieser Arbeit wurden Phosphoren Proben unter einer Argon Atmosphäre hergestellt und in einem Rasterelektronenmikroskop abgebildet. Durch die einzigartigen Eigenschaften des CANVAS ultra-hoch-Vakuum Systems können die Proben dabei ohne Kontakt zur Außenwelt transportiert, gelagert und bearbeitet werden. Eine Untersuchung der Proben ergab großflächige Kontamination durch Kohlenwasserstoffe, daher wurden einige Reinigungsmethoden getestet. Zusätzlich konnte die Amorphisierung einer dünnen Phosphoren Probe durch Laser-Bearbeitung beobachtet werden. Da Phosphoren unter Einfluss des Elektronen-Strahls Schicht-für-Schicht abgetragen wird, wurden Phosphorene-Graphen Heterostrukturen hergestellt, welche eine erhöhte Stabilität aufweisen. In einer Diskussion der Abtragungsmechanismen stellte sich chemisches Ätzen als ein wichtiger Faktor heraus. Ein signifikanter Teil der Ätzstoffe stammt dabei wahrscheinlich aus der Kontamination, welche große Teile der Proben bedeckt.
description: Black phosphorous (BP) is a two-dimensional material that has attracted a huge amount of interest due to its anisotropic structure and promising electronic, optical and mechanical properties. However, BP degrades rapidly under ambient conditions, which severely limits its usefulness in applications. In order to find degradation-mitigating strategies, it is important to understand the degradation mechanisms down to the atomic scale. In this study, BP samples were produced in an inert atmosphere, and introduced into the CANVAS ultra high vacuum system without being exposed to ambient conditions. As the samples were nonetheless severely contaminated by hydrocarbon compounds, several cleaning methods were tested. Additionally, the amorphization of few-layer BP under laser irradiation was observed. The degradation mechanisms are discussed and the role of chemical etching due to reactive oxygen species in the BP surface contamination is emphasised. To increase the stability of BP under the electron beam, BP-graphene heterostructures were also produced and analyzed. The heterostructures disintegrated significantly slower than pure BP, which makes it easier to study the properties of thin BP samples.
Linear-in-$Δ$ Lower Bounds in the LOCAL Model
Creators: name: Göös, Mika
name: Hirvonen, Juho
name: Suomela, Jukka
Publisher: name: arXiv
Year: 2013
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Computational Complexity (cs.CC)
subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences

description: By prior work, there is a distributed algorithm that finds a maximal fractional matching (maximal edge packing) in $O(Δ)$ rounds, where $Δ$ is the maximum degree of the graph. We show that this is optimal: there is no distributed algorithm that finds a maximal fractional matching in $o(Δ)$ rounds. Our work gives the first linear-in-$Δ$ lower bound for a natural graph problem in the standard model of distributed computing---prior lower bounds for a wide range of graph problems have been at best logarithmic in $Δ$.
description: 1 + 21 pages, 10 figures
Software Process Models and Analysis on Failure of Software Development Projects
Creators: name: Kaur, Rupinder
name: Sengupta, Jyotsna
Publisher: name: arXiv
Year: 2013
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: The software process model consists of a set of activities undertaken to design, develop and maintain software systems. A variety of software process models have been designed to structure, describe and prescribe the software development process. The software process models play a very important role in software development, so it forms the core of the software product. Software project failure is often devastating to an organization. Schedule slips, buggy releases and missing features can mean the end of the project or even financial ruin for a company. Oddly, there is disagreement over what it means for a project to fail. In this paper, discussion is done on current process models and analysis on failure of software development, which shows the need of new research.
title: Die Bedeutung der motorischen Grundeigenschaft Kraft auf die Laufleistung in leichtathletischen Disziplinen der Mittel- und Langstrecke
Creators: name: Samwald, Andreas
Year: 2023

description: Um im Bereich der Mittel- und Langstrecke in der Leichtathletik erfolgreich zu sein, werden bei AthletInnen unterschiedlichste Arten des Lauftrainings angewandt. Laut aktuellem Forschungsstand ist eine Kombination aus Kraft- und Lauftraining am besten geeignet, um für Leistungssteigerungen bei den AthletInnen zu sorgen. Ziel dieser Arbeit ist einerseits, einen Überblick über den aktuellen Forschungsstand zum Thema „Krafttraining im Bereich Mittel- und Langstrecke für LäuferInnen“ zu geben und andererseits die Auswirkungen von unterschiedlichsten Krafttrainingsarten für diese Laufdistanzen zu untersuchen. Es werden mit Hilfe von Ein – und Ausschlusskriterien 23 von 91 Studien aus der Online Datenbank „PubMed“ für den Ergebnisteil ausgewählt. Dieser systematische Review wird im Rahmen der PRISMA (Preferred Reporting Items for Systematic Reviews and MetaAnalysis) Statement Richtlinien durchgeführt. Es werden dabei folgenden Krafttrainingsarten untersucht: Kraftausdauer, Schnellkraft, Schnellkraftausdauer, Maximalkraft, Hypertrophie, Explosivkraft und Reaktivkraft. Die essenziellste Erkenntnis, die man aus dieser Masterarbeit ziehen kann, lautet, dass man dazu tendieren soll, Maximal- und Schnellkrafttraining in Kombination mit unterschiedlichsten Lauftrainingsformen zu kombinieren. Je kürzer die Distanzen sind, umso mehr soll man auch Explosivkrafttraining in die Trainingsplanung aufnehmen. Je länger die Laufdistanzen werden, umso mehr soll man auf Maximal- und Schnellkrafttraining setzen. Neben der Interventionsdauer, den Vorbereitungsphasen, der Aneinanderreihung der Trainingsinterventionen und der Unterscheidung zwischen den Distanzen Mittel- und Langstrecke, müssen vor allem im Bereich der geschlechterspezifischen Unterschiede die Ergebnisse dieses systematischen Reviews kritisch angesehen werden. Daraus resultiert, dass weitere Forschungsarbeit in diesem Themenkomplex stattfinden muss. Speziell müssen dabei auf geschlechterspezifische Unterscheidungen eingegangen und mehr weibliche Probandinnen in Studien rekrutiert werden.
A "configurational-entropy-loss" law for the non-Arrhenius relaxation in disordered systems
Creators: name: Wang, Yi-zhen
name: Zhang, X. Frank
name: Zhang, Jin-xiu
Publisher: name: arXiv
Year: 2012
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Based on Nowick's self-induced ordering theory, we develop a new configurational-entropy relation to describe the non-Arrhenius temperature(T)-dependent relaxation in disordered systems. Both the configurational-entropy loss and the coupling interaction among relaxing units (RUs) are explicitly introduced in this relation; thus, it offers a novel connection between kinetics and thermodynamics that is different from the Adam-Gibbs (A-G) entropy relation, and it generalizes several well-known currently used relations. The present relation can provide direct and more accurate estimates of (i) the intrinsic activation enthalpy, (ii) the T-evolvement of the systematic configurational entropy loss and (iii) the self-induced ordering temperature Tc, which characterizes the coupling interaction among RUs. Application of the theory to experimental relaxation-time data for typical organic liquids demonstrates its validity.
description: 15 pages, 2 figures
NFDI4Chem Terminology Service - News & Updates - Fostering the Community Curation of Chemical Ontologies
Creators: name: Strömert, Philip
Publisher: name: Zenodo
Year: 2023

description: This presentation was given at the 2nd Ontologies4Chem Workshop to provide an update on the new features of the NFDI4Chem Terminology Service in the context of curating chemical ontologies collaboratively.
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Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under the National Research Data Infrastructure – NFDI4Chem – Projektnummer 441958208.
title: Using COVID-19 Pandemic as a Prism: A Systematic Review of Methodological Approaches and the Quality of Empirical Studies on Physical Activity Behavior Change
Creators: name: Brand, Ralf
name: Nosrat, Sanaz
name: Späth, Constantin
name: Timme, Sinika
Publisher: name: Universitätsverlag Potsdam
Year: 2022
Subjects: subject: 796 Sportarten, Sportspiele

description: Background: The COVID-19 pandemic has highlighted the importance of scientific endeavors. The goal of this systematic review is to evaluate the quality of the research on physical activity (PA) behavior change and its potential to contribute to policy-making processes in the early days of COVID-19 related restrictions. Methods: We conducted a systematic review of methodological quality of current research according to PRISMA guidelines using Pubmed and Web of Science, of articles on PA behavior change that were published within 365 days after COVID-19 was declared a pandemic by the World Health Organization (WHO). Items from the JBI checklist and the AXIS tool were used for additional risk of bias assessment. Evidence mapping is used for better visualization of the main results. Conclusions about the significance of published articles are based on hypotheses on PA behavior change in the light of the COVID-19 pandemic. Results: Among the 1,903 identified articles, there were 36% opinion pieces, 53% empirical studies, and 9% reviews. Of the 332 studies included in the systematic review, 213 used self-report measures to recollect prepandemic behavior in often small convenience samples. Most focused changes in PA volume, whereas changes in PA types were rarely measured. The majority had methodological reporting flaws. Few had very large samples with objective measures using repeated measure design (pre and during the pandemic). In addition to the expected decline in PA duration, these studies show that many of those who were active prepandemic, continued to be active during the pandemic. Conclusions: Research responded quickly at the onset of the pandemic. However, most of the studies lacked robust methodology, and PA behavior change data lacked the accuracy needed to guide policy makers. To improve the field, we propose the implementation of longitudinal cohort studies by larger organizations such as WHO to ease access to data on PA behavior, and suggest those institutions set clear standards for this research. Researchers need to ensure a better fit between the measurement method and the construct being measured, and use both objective and subjective measures where appropriate to complement each other and provide a comprehensive picture of PA behavior.
description: Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe; 790