cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Sediment contamination of an urban canal—a case study approach for an integrated assessment of organic sediment contamination
Creators: name: Ricking, Mathias
name: Frische, K.
name: Schwarzbauer, J.
Publisher: name: Freie Universität Berlin
Year: 2021
Subjects: subject: DDX-related compounds
subject: Sequential degradation
subject: Non-extractable residues (NER)
subject: DDA formation potential
subject: 500 Naturwissenschaften und Mathematik::560 Fossilien, Paläontologie::560 Paläontologie, Paläozoologie

description: Purpose The pesticide DDT and its metabolites represent a contamination risk for the aquatic environment, especially the polar metabolite DDA. The study provides a quantitative assessment of long-term pollution risks from sedimentary DDT residues with a special focus on DDA. It presents an overview of the contamination range of different DDX compounds in the sediments of a canal in Berlin (Germany), resulting from a former industrial point source that has implications for drinking water resources in the nearby area. The comprehensive analysis scheme provides information on free accessible and potentially metabolized precursors also in the non-extractable residues. This allows a quantitative assessment of the DDA pollution potential derived from the sedimentary DDT residues. Materials and methods The area was investigated for fine-grained sediment by means of a geo-electric mapping. Twelve sediment cores were taken in four areas (three in each section). A wider range of precursor metabolites has been included due to their transformation potential to the polar metabolite DDA. The sediments were analysed quantitatively for extractable and easily releasable fractions by application of a variety of degradation techniques as well as a dispersion extraction procedure on the sediment samples. These extracts were fractionated and subsequently analysed by GC-MS. Results and discussion Concentrations were obtained for extractable and bound metabolites. Different scenarios for the calculation of the amount of contaminated sediment are displayed as a tool for contamination assessment. The formation potential of DDA as the water-soluble metabolite is presented. Several precursor metabolites, e.g. DDD and DDMS, extractable from the sediment organic matter, revealed a high potential for a long-term formation of DDA, especially in the easily releasable fraction (via hydrolysis) with a mean concentration of up to 11,000 mu g g(-1)dry sediment. The resulting DDA contamination potential represents a significant pollution risk for the groundwater from a downstream waterworks area and by remobilisation into the whole ecosystem and adjacent rivers. Conclusions The application of the presented methods provides a tool for a quantitative assessment of the long-term release potential of DDA under different scenarios by a comprehensive analysis of contaminated sediments (and soils). This approach can be transferred to pollutants that are also characterized by a complex metabolism accompanied by bound residue formation.
EVALUATION OF HFI IN VIRTUAL ENVIRONMENTS: THE USE OF COLORS FOR VISUAL PEOPLE WITH DISABILITIES
Creators: name: Amanda Cativo Sena
name: Sandra Silva Farias
name: Jean Mark Lobo de Oliveira
name: Pablo Augusto da Paz Elleres
Publisher: name: Zenodo
Year: 2023
Subjects: Human-Computer Interface (HCI), visual impairment, socio-emotional development, usability, website adaptation.

description: This work aims to contribute to the teaching/learning process of visually impaired people, contextualizing the content of the Human-Computer Interface (HCI) in order to promote the socio-emotional development of these individuals. The main objective is to develop a specific website for the visually impaired, providing information on the subject of HCI. The methodology adopted follows the phases of informal reading, construction and usability testing, according to the development method proposed by Pressman (2011). The results obtained, expressed in reports and graphs, highlight the main difficulties faced by users while using the site. This information was used for the correction and adaptation of the ONE-e site, aligning it with the identified specifications.
An upper limit on the sulphur abundance in HE 1327-2326
Creators: name: Bonifacio, P.
name: Caffau, E.
name: Venn, K. A.
name: Lambert, D. L.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context: Star HE 1327-2326 is a unique object, with the lowest measured iron abundance ([Fe/H] ~ -6) and a peculiar chemical composition that includes large overabundances of C, N, and O with respect to iron. One important question is whether the chemical abundances in this star reflect the chemical composition of the gas cloud from which it was formed or if they have been severely affected by other processes, such as dust-gas winnowing. Aims: We measure or provide an upper limit to the abundance of the volatile element sulphur, which can help to discriminate between the two scenarios. Methods: We observed HE 1327-2326 with the high resolution infra-red spectrograph CRIRES at the VLT to observe the S I lines of Multiplet 3 at 1045 nm. Results: We do not detect the S I line. A 3sigma$upper limit on the equivalent width (EW) of any line in our spectrum is EW<0.66 pm. Using either one-dimensional static or three-dimensional hydrodynamical model-atmospheres, this translates into a robust upper limit of [S/H]
description: Accepted by Astronomy & Astrophysics Minor typos in the abstract corrected
Selective excitation of localized surface plasmons by structured light
Creators: name: Litvin, Igor A.
name: Mueller, Niclas S.
name: Reich, Stephanie
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: generation
subject: scattering
subject: oligomers
subject: vortex
subject: 500 Naturwissenschaften und Mathematik::530 Physik::530 Physik

description: We investigated the selective excitation of localized surface plasmons by structured light. We derive selection rules using group theory and propose a fitting integral to quantify the contribution of the eigenmodes to the absorption spectra. Based on the result we investigate three nano oligomers of different symmetry (trimer, quadrumer, and hexamer) in detail using finite-difference time-domain simulations. We show that by controlling the incident light polarization and phase pattern we are able to control the absorption and scattering spectra. Additionally, we demonstrate that the fitting between the incident light and the oligomer modes may favor a number of modes to oscillate. Dark modes produce strong changes in the absorption spectrum and bright modes in the scattering spectrum. The experimental precision (axial shift error) may be on the same order as the oligomer diameter making the orbital angular momentum selection rules robust enough for experimental observation.
Nitrogen fluorescence in air for observing extensive air showers
Creators: name: Keilhauer, B.
name: Bohacova, M.
name: Fraga, M.
name: Matthews, J.
name: Sakaki, N.
name: Tameda, Y.
name: Tsunesada, Y.
name: Ulrich, A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Extensive air showers initiate the fluorescence emissions from nitrogen molecules in air. The UV-light is emitted isotropically and can be used for observing the longitudinal development of extensive air showers in the atmosphere over tenth of kilometers. This measurement technique is well-established since it is exploited for many decades by several cosmic ray experiments. However, a fundamental aspect of the air shower analyses is the description of the fluorescence emission in dependence on varying atmospheric conditions. Different fluorescence yields affect directly the energy scaling of air shower reconstruction. In order to explore the various details of the nitrogen fluorescence emission in air, a few experimental groups have been performing dedicated measurements over the last decade. Most of the measurements are now finished. These experimental groups have been discussing their techniques and results in a series of Air Fluorescence Workshops commenced in 2002. At the 8$^{\rm{th}}$ Air Fluorescence Workshop 2011, it was suggested to develop a common way of describing the nitrogen fluorescence for application to air shower observations. Here, first analyses for a common treatment of the major dependences of the emission procedure are presented. Aspects like the contributions at different wavelengths, the dependence on pressure as it is decreasing with increasing altitude in the atmosphere, the temperature dependence, in particular that of the collisional cross sections between molecules involved, and the collisional de-excitation by water vapor are discussed.
description: 12 pages, 17 figures, 2 tables, International Symposium on Future Directions in UHECR Physics, 13-16 February 2012, CERN, Geneva (Switzerland); the updated version corrects for a typo in Eq. (1)
Insectivorous birds can see and smell systemically herbivore-induced pines
Creators: name: Mäntyla, Elina
name: Kipper, Silke
name: Hilker, Monika
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: herbivory
subject: olfaction
subject: systemic induction
subject: vision
subject: volatile organic compounds
subject: 500 Naturwissenschaften und Mathematik::590 Tiere (Zoologie)::598 Aves (Vögel)

description: Several studies have shown that insectivorous birds are attracted to herbivoredamaged trees even when they cannot see or smell the actual herbivores or their feces. However, it often remained an open question whether birds are attracted by herbivore-induced changes in leaf odor or in leaf light reflectance or by both types of changes. Our study addressed this question by investigating the response of great tits (Parus major) and blue tits (Cyanistes caeruleus) to Scots pine (Pinus sylvestris) damaged by pine sawfly larvae (Diprion pini). We released the birds individually to a study booth, where they were simultaneously offered a systemically herbivore-induced and a noninfested control pine branch. In the first experiment, the birds could see the branches, but could not smell them, because each branch was kept inside a transparent, airtight cylinder. In the second experiment, the birds could smell the branches, but could not see them, because each branch was placed inside a nontransparent cylinder with a mesh lid. The results show that the birds were more attracted to the herbivore-induced branch in both experiments. Hence, either type of the tested cues, the herbivore-induced visual plant cue alone as well as the olfactory cues per se, is attractive to the birds.
The Star Formation Rate of Turbulent Magnetized Clouds: Comparing Theory, Simulations, and Observations
Creators: name: Federrath, Christoph
name: Klessen, Ralf S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We derive and compare six theoretical models for the star formation rate (SFR) - the Krumholz & McKee (KM), Padoan & Nordlund (PN), and Hennebelle & Chabrier (HC) models, and three multi-freefall versions of these, suggested by HC - all based on integrals over the log-normal distribution of turbulent gas. We extend all theories to include magnetic fields, and show that the SFR depends on four basic parameters: (1) virial parameter alpha_vir; (2) sonic Mach number M; (3) turbulent forcing parameter b, which is a measure for the fraction of energy driven in compressive modes; and (4) plasma beta=2(M_A/M)^2 with the Alfven Mach number M_A. We compare all six theories with MHD simulations, covering cloud masses of 300 to 4x10^6 solar masses and Mach numbers M = 3 to 50 and M_A = 1 to infinity, with solenoidal (b=1/3), mixed (b=0.4) and compressive turbulent (b=1) forcings. We find that the SFR increases by a factor of four between M=5 and 50 for compressive forcing and alpha_vir~1. Comparing forcing parameters, we see that the SFR is more than 10x higher with compressive than solenoidal forcing for Mach 10 simulations. The SFR and fragmentation are both reduced by a factor of two in strongly magnetized, trans-Alfvenic turbulence compared to hydrodynamic turbulence. All simulations are fit simultaneously by the multi-freefall KM and multi-freefall PN theories within a factor of two over two orders of magnitude in SFR. The simulated SFRs cover the range and correlation of SFR column density with gas column density observed in Galactic clouds, and agree well for star formation efficiencies SFE = 1% to 10% and local efficiencies epsilon = 0.3 to 0.7 due to feedback. We conclude that the SFR is primarily controlled by interstellar turbulence, with a secondary effect coming from magnetic fields.
description: 34 pages, 12 figures, ApJ in press, movies at http://www.ita.uni-heidelberg.de/~chfeder/pubs/sfr/sfr.shtml
ELES, NÓS E OS OUTROS
Creators: name: Santana, José Cláudio Pavão
Publisher: name: Zenodo - Cadernos da Pena do Pavao
Year: 2023

description: Ano 05 – n. 05/2017
Acho que a voz de Paula Toller me acordou hoje. Sim, acordei com o refrão na cabeça daquela música do Kid Abelha que termina com o verso: "Depois de você, os outros são os outros...".
Uncertainties in the calibrations of star formation rate
Creators: name: Zhang, Fenghui
name: Li, Lifang
name: Kang, Xiaoyu
name: Zhuang, Yulong
name: Han, Zhanwen
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The calibrations of star formation rate (SFR) are prone to be affected by many factors, such as metallicity, initial mass function (IMF), evolutionary population synthesis (EPS) models and so on. In this paper we will discuss the effects of binary interactions, metallicity, EPS models and IMF on several widely used SFR calibrations based on the EPS models of Yunnan with and without binary interactions, BC03, SB99, PEGASE and POPSTAR. The inclusion of binary interactions makes these SFR conversion coefficients smaller (less than 0.2dex), and these differences increase with metallicity. The differences in the calibration coefficient between SFR and the luminosity of $\rm Hα$ recombination line (C$_{\rm Hα}$) and that between SFR and the ultraviolet (UV) fluxes at 1500 and 2800\,$\rm Å$ (C$_{i, {\rm UV}}$), caused by IMF, are independent of metallicity (0.03-0.33\,dex) except $Δ$C$_{\rm Hα, IMF}$ when using the POPSTAR and $Δ$C$_{i, {\rm UV, IMF}}$ when using the PEGASE models. Moreover, we find that $L_{\rm 2800}$ is not suitable to the linear calibration of SFR at low metallicities. At last, we compare the effects of these several factors on the SFR calibrations considered in this paper. The effects of metallicity/IMF and EPS models on the C$_{\rm Hα}$ and C$_{\rm FIR}$ (the conversion coefficient between SFR and the far-infrared flux) are the largest among these factors, respectively. For the calibration between SFR and C$_{i, {\rm UV}}$, the effects of these several factors are comparable.
description: 17 pages, 7 figures, 9 tables, accepted by MNRAS
Consistent Probabilistic Description of the Neutral Kaon System
Creators: name: Bernabeu, J.
name: Mavromatos, N. E.
name: Villanueva-Perez, P.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The neutral Kaon system has both CP violation in the mass matrix and a non-vanishing lifetime difference in the width matrix. This leads to an effective Hamiltonian which is not a normal operator, with incompatible (non-commuting) masses and widths. In the Weisskopf-Wigner Approach (WWA), by diagonalizing the entire Hamiltonian, the unphysical non-orthogonal "stationary" states $K_{L,S}$ are obtained. These states have complex eigenvalues whose real (imaginary) part does not coincide with the eigenvalues of the mass (width) matrix. In this work we describe the system as an open Lindblad-type quantum mechanical system due to Kaon decays. This approach, in terms of density matrices for initial and final states, provides a consistent probabilistic description, avoiding the standard problems because the width matrix becomes a composite operator not included in the Hamiltonian. We consider the dominant-decay channel to two pions, so that one of the Kaon states with definite lifetime becomes stable. This new approach provides results for the time dependent decay rates in agreement with those of the WWA.
description: 10 pages latex, non-trivial observations and clarifications made compared to previous version, concerning interpretation of results (relevant parametrization) which leads to agreement of time-dependent rates with those of WWA. References added. Matches version to appear in Phys. Lett. B
$Υ$-meson pair production at LHC
Creators: name: Berezhnoy, A. V.
name: Likhoded, A. K.
name: Novoselov, A. A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Theoretical predictions for $pp\to 2 Υ+X$ cross section at $\sqrt{s}=8$ TeV for the LHCb and ATLAS kinematical conditions are obtained. A possibility to observe the new hypothetical particles containing two valence $b$-quarks and two valence $\bar{b}$-quarks is discussed.
description: 12 page, 5 figures. Several references have been added. English has been improved
Data assimilation for stratified convection
Creators: name: Svedin, Andreas
name: Cuellar, Milena C.
name: Brandenburg, Axel
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We show how the 3DVAR data assimilation methodology can be used in the astrophysical context of a two-dimensional convection flow. We study the way this variational approach finds best estimates of the current state of the flow from a weighted average of model states and observations. We use numerical simulations to generate synthetic observations of a vertical two-dimensional slice of the outer part of the solar convection zone for varying noise levels and implement 3DVAR when the covariance matrices are scalar. Our simulation results demonstrate the capability of 3DVAR to produce error estimates of system states between up to tree orders of magnitude below the original noise level present in the observations. This work exemplifies the importance of applying data assimilation techniques in simulations of the stratified convection.
Sources of Salinization of Groundwater in the Lower Yarmouk Gorge, East of the River Jordan
Creators: name: Möller, Peter
name: De Lucia, Marco
name: Rosenthal, Eliahu
name: Inbar, Nimrod
name: Salameh, Elias
name: Magri, Fabien
name: Siebert, Christian
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: Hauran Plateau
subject: Golan Heights
subject: Ajloun Dome
subject: Yarmouk basin
subject: salinization
subject: mixing of water types
subject: statistical modelling
subject: 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften

description: In the Lower Yarmouk Gorge the chemical composition of regional, fresh to brackish, mostly thermal groundwater reveals a zonation in respect to salinization and geochemical evolution, which is seemingly controlled by the Lower Yarmouk fault (LYF) but does not strictly follow the morphological Yarmouk Gorge. South of LYF, the artesian Mukeihbeh well field region produces in its central segment groundwaters, an almost pure basaltic-rock type with a low contribution (<0.3 vol-%) of Tertiary brine, hosted in deep Cretaceous and Jurassic formations. Further distal, the contribution of limestone water increases, originating from the Ajloun Mountains in the South. North of the LYF, the Mezar wells, the springs of Hammat Gader and Ain Himma produce dominantly limestone water, which contains 0.14-3 vol-% of the Tertiary brine, and hence possesses variable salinity. The total dissolved equivalents, TDE, of solutes gained by water/rock interaction (WRI) and mixing with brine, TDEWRI+brine, amount to 10-70% of total salinity in the region comprising the Mukheibeh field, Ain Himma and Mezar 3 well; 55-70% in the springs of Hammat Gader; and 80-90% in wells Mezar 1 and 2. The type of salinization indicates that the Lower Yarmouk fault seemingly acts as the divide between the Ajloun and the Golan Heights-dominated groundwaters.
Strong Coupling and Bounds on the Graviton Mass in Massive Gravity
Creators: name: Burrage, Clare
name: Kaloper, Nemanja
name: Padilla, Antonio
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The theory of a single massive graviton has a cutoff much below its Planck scale, because the extra modes from the graviton multiplet involve higher derivative self-interactions, controlled by a scale convoluted from the small graviton mass. Generically, these correct the propagator by environmental effects. The resulting effective cutoff depends on the environmental parameters and the graviton mass. Requiring the theory to be perturbative down to ${\cal O}(1) mm$, we derive bounds on the graviton mass, corresponding to $\gtrsim {\cal O}(1) meV$ for the generic case, and somewhat weaker bounds in cases of fine-tuning. In all cases the mass is required to be much too large for the theory to conform with GR at cosmological distances. Similar results also hold in quartic and quintic Galileon theory.
description: v3: typos corrected, conclusions unchanged
LIBERDADE DE EXPRESSÃO
Creators: name: Santana, José Cláudio Pavão
Publisher: name: Zenodo - Cadernos da Pena do Pavao
Year: 2023

description: Ano 05 – n. 03/2017
A liberdade, depois da vida, certamente é um dos bens mais significativos para o homem. Não fosse assim e de que valeria a pena viver?
A liberdade de expressão entra nesse contexto como direito que todo homem tem de manifestar suas ideias e por elas suportar o ônus do pensar.
Studying the properties of galaxy cluster morphology estimators
Creators: name: Weißmann, A.
name: Böhringer, H.
name: Suhada, R.
name: Ameglio, S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: X-ray observations of galaxy clusters reveal a large range of morphologies with various degrees of disturbance, showing that the assumptions of hydrostatic equilibrium and spherical shape which are used to determine the cluster mass from X-ray data are not always satisfied. It is therefore important for the understanding of cluster properties as well as for cosmological applications to detect and quantify substructure in X-ray images of galaxy clusters. Two promising methods to do so are power ratios and center shifts. Since these estimators can be heavily affected by Poisson noise and X-ray background, we performed an extensive analysis of their statistical properties using a large sample of simulated X-ray observations of clusters from hydrodynamical simulations. We quantify the measurement bias and error in detail and give ranges where morphological analysis is feasible. A new, computationally fast method to correct for the Poisson bias and the X-ray background contribution in power ratio and center shift measurements is presented and tested for typical XMM-Newton observational data sets. We studied the morphology of 121 simulated cluster images and establish structure boundaries to divide samples into relaxed, mildly disturbed and disturbed clusters. In addition, we present a new morphology estimator - the peak of the 0.3-1 r500 P3/P0 profile to better identify merging clusters. The analysis methods were applied to a sample of 80 galaxy clusters observed with XMM-Newton. We give structure parameters (P3/P0 in r500, w and P3/P0_max) for all 80 observed clusters. Using our definition of the P3/P0 (w) substructure boundary, we find 41% (47%) of our observed clusters to be disturbed.
description: Replaced to match version published in A&A, Eq. 1 corrected
Parecer: investigação criminal digital e processo penal
Creators: name: Geraldo Prado
Publisher: name: Zenodo
Year: 2023
Subjects: Investigação criminal digital; Prova digital; Cadeia de custódia das provas digitais.

description: Creio que o interesse na publicação do parecer reside no fato de o estudo diferenciar as duas etapas da persecução penal sob o ângulo do processo digital: a investigação criminal digital e o processo penal digital em sentido estrito. A abordagem reforça o que se tem investigado relativamente ao tema da prova digital, no entanto deslocando a ênfase da prova digital para o procedimento em si. Uma investigação criminal digital tem nuances que a autonomizam e que exigem tratamento jurídico adequado a ela. A correta compreensão do fenômeno pode auxiliar o intérprete no que toca à definição dos efeitos jurídicos da violação das regras do devido processo legal digital, examinando hipótese de contaminação dos atos do processo pelos da investigação.
Goals aligned: Predictors of common goal identification in educational cross-sectoral collaboration initiatives
Creators: name: Kolleck, Nina
name: Rieck, Angelika
name: Yemini, Miri
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: Social network analysis
subject: common goal identification
subject: cross-sectoral collaboration
subject: educational network
subject: third-sector involvement in education
subject: mixed methods
subject: 300 Sozialwissenschaften::370 Bildung und Erziehung::370 Bildung und Erziehung

description: The rise of cross-sectoral collaboration initiatives has been widely documented. While schools and third-sector organizations share important educational goals in these initiatives, the predictors of their identification with common goals have not been examined systemically to date. This article analyses predictors of common goal identification within educational collaborative initiatives through a case study of a German initiative aimed at tackling inequality in education. By implementing a mixed-methods design - including surveys, semi-structured interviews and social network analysis, combined with logistic regression and qualitative content analysis - we demonstrate that an actor's identification with the common goal is shaped not only by individual characteristics, but also by his/her relative position within the collaboration. Findings of this study have practical implications for networked leadership and school principals' work and training, since they inform regarding the particular settings, skills and knowledge needed for managing cross-sectoral collaboration to the benefit of schools.
Signatures of technetium oxidation states: a new approach
Creators: name: Bauters, Stephen
name: Scheinost, Andreas C.
name: Schmeide, Katja
name: Weiss, Stephan
name: Dardenne, Kathy
name: Rothe, Jörg
name: Mayordomo, Natalia
name: Steudtner, Robin
name: Stumpf, Thorsten
name: Abram, Ulrich
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: absorption-spectra
subject: complexes
subject: chemistry
subject: 500 Naturwissenschaften und Mathematik::540 Chemie::546 Anorganische Chemie

description: A general strategy for the determination of Tc oxidation state by new approach involving X-ray absorption near edge spectroscopy (XANES) at the Tc L-3 edge is shown. A comprehensive series of Tc-99 compounds, ranging from oxidation states I to VII, was measured and subsequently simulated within the framework of crystal-field multiplet theory. The observable trends in the absorption edge energy shift in combination with the spectral shape allow for a deeper understanding of complicated Tc coordination chemistry. This approach can be extended to numerous studies of Tc systems as this method is one of the most sensitive methods for accurate Tc oxidation state and ligand characterization.
Topological superfluid phases of an atomic Fermi gas with in- and out-of-plane Zeeman fields and equal Rashba-Dresselhaus spin-orbit coupling
Creators: name: Iskin, M.
name: Subasi, A. L.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We analyze the effects of in- and out-of-plane Zeeman fields on the BCS-BEC evolution of a Fermi gas with equal Rashba-Dresselhaus (ERD) spin-orbit coupling (SOC). We show that the ground state of the system involves novel gapless superfluid phases that can be distinguished with respect to the topology of the momentum-space regions with zero excitation energy. For the BCS-like uniform superfluid phases with zero center-of-mass momentum, the zeros may correspond to one or two doubly-degenerate spheres, two or four spheres, two or four concave spheroids, or one or two doubly-degenerate circles, depending on the combination of Zeeman fields and SOC. Such changes in the topology signal a quantum phase transition between distinct superfluid phases, and leave their signatures on some thermodynamic quantities. We also analyze the possibility of Fulde-Ferrell-Larkin-Ovchinnikov (FFLO)-like nonuniform superfluid phases with finite center-of-mass momentum and obtain an even richer phase diagram.
description: 9 pages with 5 figures; FFLO analysis included
Light intensity and spectral distribution affect chytrid infection of cyanobacteriaviamodulation of host fitness
Creators: name: Tao, Yile
name: Wolinska, Justyna
name: Hölker, Franz
name: Agha, Ramsy
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: Parasite traits
subject: Planktothrix
subject: Rhyzophidum
subject: specificity
subject: transmission
subject: zoospores
subject: 500 Naturwissenschaften und Mathematik::570 Biowissenschaften; Biologie::570 Biowissenschaften; Biologie

description: Light gradients are an inherent feature in aquatic ecosystems and play a key role in shaping the biology of phytoplankton. Parasitism by chytrid fungi is gaining increasing attention as a major control agent of phytoplankton due to its previously overlooked ubiquity, and profound ecological and evolutionary consequences. Despite this interest, if and how light conditions modulate phytoplankton chytridiomycosis remains poorly studied. We investigated life-history traits of a chytrid parasite,Rhizophydium megarrhizum, under different light intensities and spectral compositions when infecting two closely related planktonic cyanobacteria with different light-harvesting strategies:Planktothrix rubescensandP. agardhii. In general, parasite transmission was highest under light conditions (both intensity and quality) that maximized growth rates for uninfected cyanobacteria. Chytrid encystment on hosts was significantly affected by light intensity and host strain identity. This likely resulted from higher irradiances stimulating the increased discharge of photosynthetic by-products, which drive parasite chemotaxis, and from strain-specific differences at the cell-surface. Comparisons of parasite transmission and host growth rates under different light conditions suggest the potential for epidemic development at higher irradiances, whereas host and parasite could coexist without epidemic outbreaks at lower light levels. These results illustrate the close relationship between parasite transmission and host fitness, which is ultimately modulated by the external environment.
The CMSSM and NUHM1 in Light of 7 TeV LHC, B_s to mu+mu- and XENON100 Data
Creators: name: Buchmueller, O.
name: Cavanaugh, R.
name: Citron, M.
name: De Roeck, A.
name: Dolan, M. J.
name: Ellis, J. R.
name: Flacher, H.
name: Heinemeyer, S.
name: Isidori, G.
name: Marrouche, J.
name: Santos, D. Martinez
name: Nakach, S.
name: Olive, K. A.
name: Rogerson, S.
name: Ronga, F. J.
name: de Vries, K. J.
name: Weiglein, G.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We make a frequentist analysis of the parameter space of the CMSSM and NUHM1, using a Markov Chain Monte Carlo (MCMC) with 95 (221) million points to sample the CMSSM (NUHM1) parameter spaces. Our analysis includes the ATLAS search for supersymmetric jets + MET signals using ~ 5/fb of LHC data at 7 TeV, which we apply using PYTHIA and a Delphes implementation that we validate in the relevant parameter regions of the CMSSM and NUHM1. Our analysis also includes the constraint imposed by searches for B_s to mu+mu- by LHCb, CMS, ATLAS and CDF, and the limit on spin-independent dark matter scattering from 225 live days of XENON100 data. We assume M_h ~ 125 GeV, and use a full set of electroweak precision and other flavour-physics observables, as well as the cold dark matter density constraint. The ATLAS 5/fb constraint has relatively limited effects on the 68 and 95% CL regions in the (m_0, m_1/2) planes of the CMSSM and NUHM1. The new B_s to mu+mu- constraint has greater impacts on these CL regions, and also impacts significantly the 68 and 95% CL regions in the (M_A, tan beta) planes of both models, reducing the best-fit values of tan beta. The recent XENON100 data eliminate the focus-point region in the CMSSM and affect the 68 and 95% CL regions in the NUHM1. In combination, these new constraints reduce the best-fit values of m_0, m_1/2 in the CMSSM, and increase the global chi^2 from 31.0 to 32.8, reducing the p-value from 12% to 8.5%. In the case of the NUHM1, they have little effect on the best-fit values of m_0, m_1/2, but increase the global chi^2 from 28.9 to 31.3, thereby reducing the p-value from 15% to 9.1%.
description: 27 pages, 17 pdf figures
O GUARDIÃO E O DONO
Creators: name: Santana, José Cláudio Pavão
Publisher: name: Zenodo - Cadernos da Pena do Pavao
Year: 2023

description: Ano 05 – n. 02/2017
Não é demais lembrar que a Constituição não é norma de etiqueta. É norma conpromissária que deve ser observada pelo compromisso que encerra.
De quando em vez, entretanto, o dito e o não dito Constitucional têm sido alvo do ultraje de egos e interesses que dão bem a dimensão de a quanto anda está República. É lastimável.
B. Joassart, H. Delehaye, Hagiographie critique et modernism. Bd. 1, Préface de R. Aubert; Bd. 2, Dossier documentaire, 2000
Creators: name: Von Der Nahmer, Dieter
Publisher: name: Francia
Year: 2019

description: Francia, Bd. 29 Nr. 1 (2002)
Synthesis, Structure and Bonding Analysis of the Zwitterionic PPP-Pincer Complex (6-Ph2P-Ace-5-)2P(O)AuCl2
Creators: name: Duvinage, Daniel
name: Lork, Enno
name: Grabowsky, Simon
name: Mebs, Stefan
name: Beckmann, Jens
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: pincer ligands
subject: secondary phosphine oxide
subject: gold complex
subject: real-space bonding indicators
subject: 500 Naturwissenschaften und Mathematik::530 Physik::530 Physik

description: The reaction of (6-Ph2P-Ace-5-)2P(O)H with (tht)AuCl3 proceeds via elimination of tetrahydrothiophene (tht) and HCl, providing the zwitterionic PPP-pincer complex (6-Ph2P-Ace-5-)2P(O)AuCl2 (1) as yellow crystals. The molecular structure of 1 was established and studied by X-ray crystallography. The electronic structure was computationally analyzed using a comprehensive set of real-space bonding indicators derived from electron and electron-pair densities, providing insight into the relative contributions of covalent and non-covalent forces to the polar-covalent Au–Cl, Au–P, and P–O− bonds; the latter being one of the textbook cases for strongly polarized covalent interactions. Partial spatial complementarity between both bonding aspects is suggested by the electronic properties of the distinctively different Au–Cl bonds.
Reconstructing complex system dynamics from time series: a method comparison
Creators: name: Hassanibesheli, Forough
name: Boers, Niklas
name: Kurths, Jürgen
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: complex systems
subject: stochastic time series
subject: Langevin equation
subject: generalized Langevin equation
subject: data-driven stochastic differential equation models
subject: 500 Naturwissenschaften und Mathematik::530 Physik::530 Physik

description: Modeling complex systems with large numbers of degrees of freedom has become a grand challenge over the past decades. In many situations, only a few variables are actually observed in terms of measured time series, while the majority of variables-which potentially interact with the observed ones-remain hidden. A typical approach is then to focus on the comparably few observed, macroscopic variables, assuming that they determine the key dynamics of the system, while the remaining ones are represented by noise. This naturally leads to an approximate, inverse modeling of such systems in terms of stochastic differential equations (SDEs), with great potential for applications from biology to finance and Earth system dynamics. A well-known approach to retrieve such SDEs from small sets of observed time series is to reconstruct the drift and diffusion terms of a Langevin equation from the data-derived Kramers-Moyal (KM) coefficients. For systems where interactions between the observed and the unobserved variables are crucial, the Mori-Zwanzig formalism (MZ) allows to derive generalized Langevin equations that contain non-Markovian terms representing these interactions. In a similar spirit, the empirical model reduction (EMR) approach has more recently been introduced. In this work we attempt to reconstruct the dynamical equations of motion of both synthetical and real-world processes, by comparing these three approaches in terms of their capability to reconstruct the dynamics and statistics of the underlying systems. Through rigorous investigation of several synthetical and real-world systems, we confirm that the performance of the three methods strongly depends on the intrinsic dynamics of the system at hand. For instance, statistical properties of systems exhibiting weak history-dependence but strong state-dependence of the noise forcing, can be approximated better by the KM method than by the MZ and EMR approaches. In such situations, the KM method is of a considerable advantage since it can directly approximate the state-dependent noise. However, limitations of the KM approximation arise in cases where non-Markovian effects are crucial in the dynamics of the system. In these situations, our numerical results indicate that methods that take into account interactions between observed and unobserved variables in terms of non-Markovian closure terms (i.e., the MZ and EMR approaches), perform comparatively better.
Nonlinear Dirac equation solitary waves in external fields
Creators: name: Mertens, Franz G.
name: Quintero, Niurka R.
name: Cooper, Fred
name: Khare, Avinash
name: Saxena, Avadh
Publisher: name: arXiv
Year: 2012
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the nonlinear Dirac equations (NLDE's) in 1+1 dimension with scalar-scalar self interaction $\frac{g^2}{κ+1} ({\bPsi} Ψ)^{κ+1}$ in the presence of various external electromagnetic fields. Starting from the exact solutions for the unforced problem we study the behavior of solitary wave solutions to the NLDE in the presence of a wide variety of fields in a variational approximation depending on collective coordinates which allows the position, width and phase of these waves to vary in time. We find that in this approximation the position $q(t)$ of the center of the solitary wave obeys the usual behavior of a relativistic point particle in an external field. For time independent external fields we find that the energy of the solitary wave is conserved but not the momentum which becomes a function of time. We postulate that similar to the nonlinear Schr{ö}dinger equation (NLSE) that a sufficient dynamical condition for instability to arise is that $ dP(t)/d \dq(t) < 0$. Here $P(t)$ is the momentum of the solitary wave, and $\dq$ is the velocity of the center of the wave in the collective coordinate approximation. We found for our choices of external potentials we always have $ dP(t)/d \dq(t) > 0$ so when instabilities do occur they are due to a different source. We investigate the accuracy of our variational approximation using numerical simulations of the NLDE and find that when the forcing term is small and we are in a regime where the solitary wave is stable, that the behavior of the solutions of the collective coordinate equations agrees very well with the numerical simulations.
description: 29 pages, 9 figures, one table
T. Schilp, Norm und Wirklichkeit religiöser Frauengemeinschaften im Frühmittelalter. Die »institutio sanctimonialium Aquisgranensis« des Jahres 816 und die Problematik der Verfassung von Frauenkommunitäten, 1998
Creators: name: Gaillard, Michèle
Publisher: name: Francia
Year: 2019

description: Francia, Bd. 29 Nr. 1 (2002)
Study of light-cone distribution amplitudes for p-wave heavy mesons
Creators: name: Hwang, Chien-Wen
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In this paper, a study of light-cone distribution amplitudes for p-wave heavy mesons is presented in both general and heavy quark frameworks. Within the light-front approach, the leading twist light-cone distribution amplitudes, ϕ_M(u) and their relevant decay constants of heavy scalar, axial-vector and tensor mesons, f_M, are formulated. The relations of some decay constants can be simplified when the heavy quark limit is taken into account. After fixing the parameters which appear in a Gaussian wave function, the corresponding decay constants are calculated and compared with those of other theoretical approaches. The curves and the first six ξmoments of ϕ_M(u) are plotted and estimated. These results all endorse the requirements of heavy quark symmetry.
description: 27 pages, 7 figures, 6 tables, version to appear in Phys. Rev. D. arXiv admin note: substantial text overlap with arXiv:1003.0972, arXiv:0906.4412
PROFESSOR, COM COMPROMISSO
Creators: name: Santana, José Cláudio Pavão
Publisher: name: Zenodo - Cadernos da Pena do Pavao
Year: 2023

description: Ano 05 – n. 12/2017
Eu poderia dizer que sinto orgulho, mas seria pouco. Neste país o compromisso com a educação se revela pelo descuidado que se tem conosco, professores.
Eu tenho é compromisso! Sim, compromisso com a educação crítica do Direito, em dias em que a classe jurídica tem comprometido muito mais a democracia do que lhe dado oxigênio.
Slow relaxations and stringlike jump motions in fragile glass-forming liquids: Breakdown of the Stokes-Einstein relation
Creators: name: Kawasaki, Takeshi
name: Onuki, Akira
Publisher: name: arXiv
Year: 2012
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We perform molecular dynamics simulation on a glass-forming liquid binary mixture with the soft-core potential in three dimensions. We investigate crossover of the configuration changes caused by stringlike jump motions. With lowering the temperature $T$, the motions of the particles composing strings become larger in sizes and displacements, while those of the particles surrounding strings become smaller. Then, the contribution of the latter to time-correlation functions tends to be long-lived as $T$ is lowered. As a result, the relaxation time $τ_α$ and the viscosity $η$ grow more steeply than the inverse diffusion constant $D^{-1}$ at low $T$, leading to breakdown of the Stokes-Einstein relation. At low $T$, the diffusion occurs as activation processes and may well be described by short-time analysis of rare jump motions with broken bonds and large displacements. Some characteristic features of the van Hove self-correlation function arise from escape jumps over high potential barriers.
Cooling-by-measurement and mechanical state tomography via pulsed optomechanics
Creators: name: Vanner, M. R.
name: Hofer, J.
name: Cole, G. D.
name: Aspelmeyer, M.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Observing a physical quantity without disturbing it is a key capability for the control of individual quantum systems. Such back-action-evading or quantum-non-demolition measurements were first introduced in the 1970s in the context of gravitational wave detection to measure weak forces on test masses by high precision monitoring of their motion. Now, such techniques have become an indispensable tool in quantum science for preparing, manipulating, and detecting quantum states of light, atoms, and other quantum systems. Here we experimentally perform rapid optical quantum-noise-limited measurements of the position of a mechanical oscillator by using pulses of light with a duration much shorter than a period of mechanical motion. Using this back-action evading interaction we performed both state preparation and full state tomography of the mechanical motional state. We have reconstructed mechanical states with a position uncertainty reduced to 19 pm, limited by the quantum fluctuations of the optical pulse, and we have performed `cooling-by-measurement' to reduce the mechanical mode temperature from an initial 1100 K to 16 K. Future improvements to this technique may allow for quantum squeezing of mechanical motion, even from room temperature, and reconstruction of non-classical states exhibiting negative regions in their phase-space quasi-probability distribution.
description: Note title change, 10 pages, 5 figures, includes supplementary information