133 research outputs found

    AI/ML-based support of satellite sensing for cloud cover classification

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    High-Resolution Near-Field Raman Microscopy of Single-Walled Carbon Nanotubes

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    We present near-field Raman spectroscopy and imaging of single isolated single-walled carbon nanotubes with a spatial resolution of ≈25  nm. The near-field origin of the image contrast is confirmed by the measured dependence of the Raman scattering signal on tip-sample distance and the unique polarization properties. The method is used to study local variations in the Raman spectrum along a single single-walled carbon nanotube

    Talking Past Each Other - A Discursive Approach to the Formation of Societal-Level Information Pathologies in the Context of the Electronic Health Card in Germany

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    An explorative case study is used to investigate the formation of information pathologies on the societal level. The paper conceptualizes these particular information pathologies as ‘interaction-related Information pathologies’ (Picot et al., Information, organization and management. Springer, Berlin, 2008) and proposes that the production of information by multiple stakeholders leads to ‘distortions’ (Cukier et al., Inf Syst J 19(2):175–196, 2009) on the societal level. This broad proposition is then explored by means of a qualitative case study of the media coverage surrounding the implementation of the ‘Electronic Health Card’ in Germany. Based on that study, the initial proposition is further specified by conceptualizing how a process of path constitution ‘distorts’ a debate from being about legitimacy of an ICT innovation to being about illegitimacy of stakeholders

    Gravitational Waves from Disks Around Spinning Black Holes: Simulations in Full General Relativity

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    We present fully general-relativistic numerical evolutions of self-gravitating tori around spinning black holes with dimensionless spin a/M=0.7a/M = 0.7 parallel or anti-parallel to the disk angular momentum. The initial disks are unstable to the hydrodynamic Papaloizou-Pringle Instability which causes them to grow persistent orbiting matter clumps. The effect of black hole spin on the growth and saturation of the instability is assessed. We find that the instability behaves similarly to prior simulations with non-spinning black holes, with a shift in frequency due to spin-induced changes in disk orbital period. Copious gravitational waves are generated by these systems, and we analyze their detectability by current and future gravitational wave observatories for large range of masses. We find that systems of 10M10 M_\odot - relevant for black hole-neutron star mergers - are detectable by Cosmic Explorer out to 300\sim300 Mpc, while DECIGO (LISA) will be able to detect systems of 1000M1000 M_\odot (105M10^5M_\odot) - relevant for disks forming in collapsing supermassive stars - out to cosmological redshift of z5z\sim5 (z1z\sim 1). Computing the accretion rate of these systems we find that these systems may also be promising sources of coincident electromagnetic signals.Comment: 15 pages, 12 figure

    Effect of magnetic fields on the dynamics and gravitational wave emission of PPI-saturated self-gravitating accretion disks: simulations in full GR

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    We explore the effect magnetic fields have on self-gravitating accretion disks around spinning black holes via numerical evolutions in full dynamical magnetohydrodynamic spacetimes. The configurations we study are unstable to the Papaloizou-Pringle Instability (PPI). PPI-saturated accretion tori have been shown to produce gravitational waves, detectable to cosmological distances by third-generation gravitational wave (GW) observatories. While the PPI operates strongly for purely hydrodynamic disks, the situation can be different for disks hosting initially small magnetic fields. Evolutions of disks without self-gravity in fixed BH spacetimes have shown that small seed fields can initiate the rapid growth of the magneto-rotational instability (MRI), which then strongly suppresses the PPI. Since realistic astrophysical disks are expected to be magnetized, PPI-generated GW signals may be suppressed as well. However, it is unclear what happens when the disk self-gravity is restored. Here, we study the impact of magnetic fields on the PPI-saturated state of a self-gravitating accretion disk around a spinning BH (χ=0.7\chi = 0.7) aligned with the disk angular momentum, as well as one around a non-spinning BH. We find the MRI is effective at reducing the amplitude of PPI modes and their associated GWs, but the systems still generate GWs. Estimating the detectability of these systems accross a wide range of masses, we show that magnetic fields reduce the maximum detection distance by Cosmic Explorer from 300Mpc (in the pure hydrodynamic case) to 45Mpc for a 10M10 M_{\odot} system, by LISA from 11500Mpc to 2700Mpc for a 2×105M2 \times 10^{5} M_{\odot} system, and by DECIGO from z5z \approx 5 down to z2z \approx 2 for a 1000M1000 M_{\odot} system

    1-(10,11-Di­hydro­dibenz­[b,f]­azepin-5-yl)­ethano­ne

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    The asymmetric unit of the title compound, Csb 16Hsb 15NO, comprises two independent mol-ecules (it A and it B), both adopting a half-boat conformation, or butterfly shape. The intramolecular dihedral angles between the benzene rings in it A and it B are 64.40(4) and 65.24(5)circ, respectively

    Physics of eccentric binary black hole mergers: A numerical relativity perspective

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    Gravitational wave observations of eccentric binary black hole mergers will provide unequivocal evidence for the formation of these systems through dynamical assembly in dense stellar environments. The study of these astrophysically motivated sources is timely in view of electromagnetic observations, consistent with the existence of stellar mass black holes in the globular cluster M22 and in the Galactic center, and the proven detection capabilities of ground-based gravitational wave detectors. In order to get insights into the physics of these objects in the dynamical, strong-field gravity regime, we present a catalog of 89 numerical relativity waveforms that describe binary systems of non-spinning black holes with mass-ratios 1q101\leq q \leq 10, and initial eccentricities as high as e0=0.18e_0=0.18 fifteen cycles before merger. We use this catalog to quantify the loss of energy and angular momentum through gravitational radiation, and the astrophysical properties of the black hole remnant, including its final mass and spin, and recoil velocity. We discuss the implications of these results for gravitational wave source modeling, and the design of algorithms to search for and identify eccentric binary black hole mergers in realistic detection scenarios.Comment: 11 pages, 5 figures, 2 appendices. A visualization of this numerical relativity waveform catalog is available at https://gravity.ncsa.illinois.edu/products/outreach/; v2: 13 pages, 5 figures, calculations for angular momentum emission and recoil velocities are now included, references added. Accepted to Phys. Rev.

    Basal and LPS-stimulated inflammatory markers and the course of individual symptoms of depression

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    Multiple studies show an association between inflammatory markers and major depressive disorder (MDD). People with chronic low-grade inflammation may be at an increased risk of MDD, often in the form of sickness behaviors. We hypothesized that inflammation is predictive of the severity and the course of a subset of MDD symptoms, especially symptoms that overlap with sickness behavior, such as anhedonia, anorexia, low concentration, low energy, loss of libido, psychomotor slowness, irritability, and malaise. We tested the association between basal and lipopolysaccharide (LPS)-induced inflammatory markers with individual MDD symptoms (measured using the Inventory of Depressive Symptomatology Self-Report) over a period of up to 9 years using multivariate-adjusted mixed models in 1147–2872 Netherlands Study of Depression and Anxiety (NESDA) participants. At baseline, participants were on average 42.2 years old, 66.5% were women and 53.9% had a current mood or anxiety disorder. We found that basal and LPS-stimulated inflammatory markers were more strongly associated with sickness behavior symptoms at up to 9-year follow-up compared with non-sickness behavior symptoms of depression. However, we also found significant associations with some symptoms that are not typical of sickness behavior (e.g., sympathetic arousal among others). Inflammation was not related to depression as a unified syndrome but rather to the presence and the course of specific MDD symptoms, of which the majority were related to sickness behavior. Anti-inflammatory strategies should be tested in the subgroup of MDD patients who report depressive symptoms related to sickness behavior
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