39,822 research outputs found
jochym/Elastic: Maintenance release
No full text<p>This is a maintenance release to force x.y.z.build versioning numbers and update zenodo DOI links in the docs.</p>
jochym/Elastic: 5.x series start
No full text<p>The new 5.0 version is API incompatible with the previous versions. It provides a new command line utility as the main user interface to the package - which hopefully will broaden the user base byond python users.</p>
<p>The new version also changes API of the library from mix-in class to the set of simple functions providing functionality of the module. The workflow of the package was also changed to prepare data - calculate - post-process style, which is better suited to serious research work.</p>
jochym/Elastic: Last release of the 4.x series
No full text<p>This is the last release of the <em>legacy</em> 4.x software. The next series will be API incompatible with this code and will include a CLI tool for doing calculations. This is a maintenance release for those who cannot upgrade. Still you better upgrade - this will not be supported for much longer and the new API is much better. And you do not need to know python to use it!</p>
Soft phonon modes in rutile TiO2
No full textThe lattice dynamics of TiO2 in the rutile crystal structure was studied by a combination of thermal diffuse scattering, inelastic x-ray scattering, and density functional perturbation theory. We experimentally confirm the existence of a predicted anomalous soft transverse acoustic mode with energy minimum at q = (1/2 1/2 1/4). The phonon energy landscape of this particular branch is reported and compared to the calculation. The harmonic calculation underestimates the phonon energies but despite this the shape of both the energy landscape and the scattering intensities are well reproduced. We find a significant temperature dependence in the energy of this transverse acoustic mode over an extended region in reciprocal space, which point to a strong role of anharmonicity in line with a substantially anharmonic mode potential-energy surface. The reported low-energy branch is quite different from the ferroelectric mode that softens at the Brillouin zone center and may help explain anomalous convergence behavior in calculating TiO2 surface properties and is potentially relevant for real behavior in TiO2 thin films
qe-doc: Mark the release published earlier for zenodo
No full text<p>Release made to mark a point in the history.</p>
Elastic: Maintenance release
No full text<a class="anchor" href="#elastic-v4010"><span class="octicon octicon-link"></span></a>Elastic v4.0.10
<p>Maintenance release to bring the code in sync with current ASE and have it fully functional in Python 2.7 and 3.4. No extensions for now but many bugs and problems fixed. Also fairly complete test case added as a separate script and verified on my system.</p>
Elastic: New versioning scheme. Update to spglib interface.
No full text<p>This is a minor maintenance release.</p>
<ul>
<li><p>The versioning scheme is switched to the one based on git tags and 'git describe' produced strings and made conformant to PEP 440 (presumably).</p></li>
<li><p>The new interface of spglib is accommodated. </p></li>
</ul>
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Crystal structure and lattice dynamics of endotaxial FeSi2 nanowires
No full textThe reduction of the dimensions of crystals to the nanometer length scale induces significant deviations in the phonon dispersions and phonon density of states (PDOS) of nanostructures compared to their bulk counterparts and novel vibrational phenomena emerge. I will present recent results of lattice dynamics study of alpha-phase FeSi2 endotaxial nanowires, epitaxially grown on Si(110), as a function of their size [1]. The experimentally obtained Fe-partial PDOS from nuclear inelastic scattering are comprehensively understood by the help of ab initio theory [2]
[1] J. Kalt, M. Sternik, B. Krause, I. Sergueev, M. Mikolasek, D.G. Merkel, D. Bessas, O. Sikora, T. Vitova, J. Göttlicher, R. Steininger, P.T. Jochym, A. Ptok, O. Leupold, H.-C. Wille, A.I. Chumakov, P. Piekarz, K. Parlinski, T. Baumbach and S. Stankov, Phys. Rev. B 102 (2020) 195414 [2] J. Kalt, M. Sternik, B. Krause, I. Sergueev, M. Mikolasek, D. Bessas, O. Sikora, T. Vitova, J. Göttlicher, R. Steininger, P.T. Jochym, A. Ptok, O. Leupold, H.-C. Wille, A. I. Chumakov, P. Piekarz, K. Parlinski, T. Baumbach and S. Stankov, Phys. Rev. B 101 (2020) 16540
Wave turbulence of a rotating array of quantized vortices in the T → 0 temperature limit
No full textThe dynamics of quantized vortices in the zero temperature limit is currently of great interest, particularly in the case of the Fermi superfluid He-B. Here we study wave turbulence, generated by the librating motion of a rotating cylindrical container filled with He-B, in the limit of vanishing viscous forces at temperatures . The polarization of the quantized vortices with respect to the axis of rotation is measured using non-invasive NMR techniques. We observe a decrease of the polarization when the librating motion is started, and a two-stage relaxation process when the modulation of the rotation velocity is stopped. The first relaxation process is associated with the dissipation of large-scale flow stored in inertial waves and the solid body rotation of the vortex array. From the decay of these energy reservoirs we determine the rate of energy dissipation of large-scale flow. The later second process is related to the relaxation of Kelvin waves on individual vortices. This process is monitored by the recovery of the polarization. The existence of a Kelvin wave cascade at the lowest temperatures is currently a central open question. We supply some evidence for the cascade
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