Theoretical insight on the LK-99 material

Two recent preprints in physics archive (arXiv) have called the attention as they claim experimental evidence that a Cu-substituted apatite material (called LK-99) exhibits superconductivity at room temperature and pressure. If this proves to be true, LK-99 will be the holy grail of superconductors. In this work, we used Density-Functional Theory calculations to elucidate some key features of the electronic structure of LK-99. Although some aspects of our calculations are preliminary, we found that: i) in the ground state of the material the ferromagnetic and antiferromagnetic configurations are practically degenerated, ii) the material is metallic, iii) the Cu atoms seem to be hosts in the lattice with not covalent bonds to other atoms and supporting almost flat bands around the Fermi level, and iv) the electron-phonon coupling of these flat bands seems to be dramatically large

Lactic acid production a bibliometric study

Bibliometrics is a documentary analysis tool that is positioning itself as a support to know and understand the study status of a specific topic. In this case, the VOSviewer software was used to determine the evolution of lactic acid production, carried out through a programmed search with the VOSviewer application, which allowed a clear and reliable bibliographic review for the topic development under study, which made possible to obtain enough material to know who, where and in what year have published about the latest advances in the production of lactic acid. The database used was Scopus, with the search equation “lactic acid” and production and “natural sources”

Quinstant Dark Energy Predictions for Structure Formation

We explore the predictions of a class of dark energy models, quinstant dark energy, concerning the structure formation in the Universe, both in the linear and non-linear regimes. Quinstant dark energy is considered to be formed by quintessence and a negative cosmological constant. We conclude that these models give good predictions for structure formation in the linear regime, but fail to do so in the non-linear one, for redshifts larger than one.Comment: 9 pages, 14 figures, "Accepted for publication in Astrophysics & Space Science

Preliminary optical design of PANIC, a wide-field infrared camera for CAHA

In this paper, we present the preliminary optical design of PANIC (PAnoramic Near Infrared camera for Calar Alto), a wide-field infrared imager for the Calar Alto 2.2 m telescope. The camera optical design is a folded single optical train that images the sky onto the focal plane with a plate scale of 0.45 arcsec per 18 micron pixel. A mosaic of four Hawaii 2RG of 2k x 2k made by Teledyne is used as detector and will give a field of view of 31.9 arcmin x 31.9 arcmin. This cryogenic instrument has been optimized for the Y, J, H and K bands. Special care has been taken in the selection of the standard IR materials used for the optics in order to maximize the instrument throughput and to include the z band. The main challenges of this design are: to produce a well defined internal pupil which allows reducing the thermal background by a cryogenic pupil stop; the correction of off-axis aberrations due to the large field available; the correction of chromatic aberration because of the wide spectral coverage; and the capability of introduction of narrow band filters (~1%) in the system minimizing the degradation in the filter passband without a collimated stage in the camera. We show the optomechanical error budget and compensation strategy that allows our as built design to met the performances from an optical point of view. Finally, we demonstrate the flexibility of the design showing the performances of PANIC at the CAHA 3.5m telescope.Comment: This paper has been presented in the SPIE of Astronomical Telescopes and Instrumentation 2008 in Marseille (France

PANIC: the new panoramic NIR camera for Calar Alto

PANIC is a wide-field NIR camera, which is currently under development for the Calar Alto observatory (CAHA) in Spain. It uses a mosaic of four Hawaii-2RG detectors and covers the spectral range from 0.8-2.5 micron(z to K-band). The field-of-view is 30x30 arcmin. This instrument can be used at the 2.2m telescope (0.45arcsec/pixel, 0.5x0.5 degree FOV) and at the 3.5m telescope (0.23arcsec/pixel, 0.25x0.25 degree FOV). The operating temperature is about 77K, achieved by liquid Nitrogen cooling. The cryogenic optics has three flat folding mirrors with diameters up to 282 mm and nine lenses with diameters between 130 mm and 255 mm. A compact filter unit can carry up to 19 filters distributed over four filter wheels. Narrow band (1%) filters can be used. The instrument has a diameter of 1.1 m and it is about 1 m long. The weight limit of 400 kg at the 2.2m telescope requires a light-weight cryostat design. The aluminium vacuum vessel and radiation shield have wall thicknesses of only 6 mm and 3 mm respectively.Comment: This paper has been presented in the SPIE of Astronomical Telescopes and Instrumentation 2008 in Marseille (France

Reservefonds gegen Naturkatastrophen auf nationaler und europäischer Ebene

Katastrophenfonds funktionieren nach dem Prinzip der Kapitalakkumulation. Sie werden teilweise auf nationaler und europäischer Ebene eingesetzt, um sich gegen die finanziellen Schäden, verursacht durch extreme Naturereignisse, zu schützen. Basierend auf Beispielen in Europa, wie dem österreichischen Katastrophenfonds sowie dem europäischen Solidaritätsfonds, werden die Vor- und Nachteile von Reservefonds aufgezeigt und mögliche Lösungsvorschläge für gegenwärtige Probleme präsentiert. Vor allem die nichtrisikobasierte Anwendung wird als Problem betrachtet. Es werden Methoden vorgestellt, wie ein wahrscheinlichkeitstheoretischer Ansatz aussehen könnte, um sowohl direkte als auch indirekte Schäden bei der Analyse mit einzubeziehen und daraus Strategien zu entwickeln, die sich langfristig als nachhaltig erweisen.Catastrophe reserve funds are used to cover the potential costs of a disaster by capital accumulation. Based on examples in Europe, especially the national disaster fund in Austria and the European Solidarity Fund, the advantages and disadvantages of such a risk management instrument are shown and possible solutions are proposed. The main criticism is the non-risk based approach of these instruments. Methodologies how one can incorporate direct as well as indirect losses within a probability based approach are presented

Protease-Activated Receptor 1 Contributes to Angiotensin II-Induced Cardiovascular Remodeling and Inflammation

Angiotensin II (Ang II) plays an important role in cardiovascular disease. It also leads to the activation of coagulation. The coagulation protease thrombin induces cellular responses by activating protease activated receptor 1 (PAR-1). We investigated if PAR-1 contributes to Ang II-induced cardiovascular remodeling and inflammation

The challenge of modelling nitrogen management at the field scale : simulation and sensitivity analysis of N2O fluxes across nine experimental sites using DailyDayCent

Peer reviewedPublisher PD