Micromechanical model of bovine Haversian bone predicts strain amplification through soft interfaces

Context. Recent observations of brown dwarf spectroscopic variability in the infrared infer the presence of patchy cloud cover. Aims. This paper proposes a mechanism for producing inhomogeneous cloud coverage due to the depletion of cloud particles through the Coulomb explosion of dust in atmospheric plasma regions. Charged dust grains Coulomb-explode when the electrostatic stress of the grain exceeds its mechanical tensile stress, which results in grains below a critical radius a < aCoulcrit being broken up. Methods. This work outlines the criteria required for the Coulomb explosion of dust clouds in substellar atmospheres, the effect on the dust particle size distribution function, and the resulting radiative properties of the atmospheric regions. Results. Our results show that for an atmospheric plasma region with an electron temperature of Te = 10 eV (≈ 105 K), the critical grain radius varies from 10-7 to 10-4 cm, depending on the grains’ tensile strength. Higher critical radii up to 10-3 cm are attainable for higher electron temperatures. We find that the process produces a bimodal particle size distribution composed of stable nanoscale seed particles and dust particles with a ≥ aCoulcrit , with the intervening particle sizes defining a region devoid of dust. As a result, the dust population is depleted, and the clouds become optically thin in the wavelength range 0:1 - 10 μm, with a characteristic peak that shifts to higher wavelengths as more sub-micrometer particles are destroyed. Conclusions. In an atmosphere populated with a distribution of plasma volumes, this will yield regions of contrasting radiative properties, thereby giving a source of inhomogeneous cloud coverage. The results presented here may also be relevant for dust in supernova remnants and protoplanetary disks.PostprintPeer reviewe

Alkaline battery containing a separator of a cross-linked copolymer of vinyl alcohol and unsaturated carboxylic acid

A battery separator for an alkaline battery is described. The separator comprises a cross linked copolymer of vinyl alcohol units and unsaturated carboxylic acid units. The cross linked copolymer is insoluble in water, has excellent zincate diffusion and oxygen gas barrier properties and a low electrical resistivity. Cross linking with a polyaldehyde cross linking agent is preferred

Spatially-Correlated Microstructure and Superconductivity in Polycrystalline Boron-Doped Diamond

Scanning tunneling spectroscopies are performed below 100~mK on nano-crystalline boron-doped diamond films characterized by Transmission Electron Microscopy and transport measurements. We demonstrate a strong correlation between the local superconductivity strength and the granular structure of the films. The study of the spectral shape, amplitude and temperature dependence of the superconductivity gap enables us to differentiate intrinsically superconducting grains that follow the BCS model, from grains showing a different behavior involving the superconducting proximity effect

Inferring the underlying multivariate structure from bivariate networks with highly correlated nodes

Funding Information: PL acknowledges financial support from Medical Research Scotland (Grant No.: RG14565). Publisher Copyright: © 2022, The Author(s).Peer reviewedPublisher PD

Multi-orbital Kondo physics of Co in Cu hosts

We investigate the electronic structure of cobalt atoms on a copper surface and in a copper host by combining density functional calculations with a numerically exact continuous-time quantum Monte Carlo treatment of the five-orbital impurity problem. In both cases we find low energy resonances in the density of states of all five Co $d$-orbitals. The corresponding self-energies indicate the formation of a Fermi liquid state at low temperatures. Our calculations yield the characteristic energy scale -- the Kondo temperature -- for both systems in good agreement with experiments. We quantify the charge fluctuations in both geometries and suggest that Co in Cu must be described by an Anderson impurity model rather than by a model assuming frozen impurity valency at low energies. We show that fluctuations of the orbital degrees of freedom are crucial for explaining the Kondo temperatures obtained in our calculations and measured in experiments.Comment: 10 pages, 10 figure

Electronic excitation spectra of the five-orbital Anderson impurity model: From the atomic limit to itinerant atomic magnetism

We study the competition of Coulomb interaction and hybridization effects in the five-orbital Anderson impurity model by means of continuous time quantum Monte Carlo, exact diagonalization, and Hartree-Fock calculations. The dependence of the electronic excitation spectra and thermodynamic ground-state properties on the hybridization strength and the form of the Coulomb interaction is systematically investigated for impurity occupation number N≈6. With increasing hybridization strength, a Kondo resonance emerges, broadens and merges with some of the upper and lower Hubbard peaks. Concomitantly, there is an increase of charge fluctuations at the impurity site. In contrast to the single-orbital model, some atomic multiplet peaks and exchange split satellites persist despite strong charge fluctuations. We find that Hund's coupling leads to a state that may be characterized as an itinerant single atom magnet. As the filling is increased, the magnetic moment decreases, but the spin freezing phenomenon persists up to N≈8. When the hybridization is weak, the positions of atomic ionization peaks are rather sensitive to shifts of the impurity on-site energies. This allows to distinguish atomic ionization peaks from quasiparticle peaks or satellites in the electronic excitation spectra. On the methodological side we show that a comparison between the spectra obtained from Monte Carlo and exact diagonalization calculations is possible if the charge fluctuations are properly matched

A Statistical Shape Model-Based Analysis of Periacetabular Osteotomies: Technical Considerations to Achieve the Targeted Correction

BACKGROUND Classic and reverse Bernese periacetabular osteotomy (PAO) have been shown to be effective for the treatment of developmental dysplasia of the hip (by classic PAO), severe acetabular retroversion (by reverse PAO), and some protrusio acetabuli (by reverse PAO). Especially in severe cases with higher degrees of correction, a relevant overlap between the osteotomized fragment and the pelvis might occur, leading to necessary fragment translation. The aim of the present study was to analyze the necessary translation as a function of the degree of correction using a statistical mean model of the pelvis according to the technique (classic PAO or reverse PAO). METHODS A mean statistical shape model of the pelvis and 2 extreme models were used to simulate rotation of the osteotomized fragment during a classic or reverse PAO and to calculate rotations from -20° to 20° in the frontal, sagittal, and transverse planes and a combination thereof. The depth and volume of the intersection between the mobilized fragment and the pelvis were calculated, and the minimum translation of the fragment necessary to avoid segment overlap was determined. RESULTS The maximum intersection distances between the pelvis and the 20° rotated fragment were 6.7 and 15.3 mm for adduction and abduction (frontal plane), 6.4 and 4.5 mm for internal and external rotation (transverse plane), and 27.8 and 9.2 mm for extension and flexion (sagittal plane). The necessary translations for 20° of fragment rotation were 7.0 and 12.8 mm for adduction and abduction (frontal plane), 4.8 and 5.0 mm for internal and external rotation (transverse plane), and 18.5 mm and 8.8 mm for extension and flexion (sagittal plane). CONCLUSIONS Acetabular reorientation with the classic or reverse PAO results in translation of the fragment and in a consequent change in the rotational center. This finding is more pronounced with higher degrees of fragment reorientation in abduction and extension; it becomes especially pronounced in reverse PAO for acetabular retroversion or protrusio acetabuli, and might limit the ability to achieve the intended improvement in overall hip biomechanics

Resonant Auger decay of the core-excited C∗^\astO molecule in intense X-ray laser fields

The dynamics of the resonant Auger (RA) process of the core-excited C$^\ast$O(1s$^{-1}\pi^\ast,v_r=0$) molecule in an intense X-ray laser field is studied theoretically. The theoretical approach includes the analogue of the conical intersections of the complex potential energy surfaces of the ground and `dressed' resonant states due to intense X-ray pulses, taking into account the decay of the resonance and the direct photoionization of the ground state, both populating the same final ionic states coherently, as well as the direct photoionization of the resonance state itself. The light-induced non-adiabatic effect of the analogue of the conical intersections of the resulting complex potential energy surfaces gives rise to strong coupling between the electronic, vibrational and rotational degrees of freedom of the diatomic CO molecule. The interplay of the direct photoionization of the ground state and of the decay of the resonance increases dramatically with the field intensity. The coherent population of a final ionic state via both the direct photoionization and the resonant Auger decay channels induces strong interference effects with distinct patterns in the RA electron spectra. The individual impact of these physical processes on the total electron yield and on the CO$^+(A^2\Pi)$ electron spectrum are demonstrated.Comment: 13 figs, 1 tabe

Editorial : Advances in the spatial and temporal evolution of oceanic arc-backarc systems

Non peer reviewe