Gravitational-wave signals from 3D supernova simulations with different neutrino-transport methods

We compare gravitational-wave (GW) signals from eight three-dimensional simulations of core-collapse supernovae from Glas et al. (2019), using two different progenitors with zero-age main sequence masses of 9 and 20 solar masses. The collapse of each progenitor was simulated four times, at two different grid resolutions and with two different neutrino transport methods, using the Aenus-Alcar code. The main goal of this study is to assess the validity of recent concerns that the so-called "Ray-by-Ray+" (RbR+) approximation is problematic in core-collapse simulations and can adversely affect theoretical GW predictions. Therefore, signals from simulations using RbR+ are compared to signals from corresponding simulations using a fully multidimensional (FMD) transport scheme. The 9 solar-mass progenitor successfully explodes, whereas the 20 solar-mass model does not. Both the standing accretion shock instability and hot-bubble convection develop in the postshock layer of the non-exploding models. In the exploding models, neutrino-driven convection in the postshock flow is established around 100 ms after core bounce and lasts until the onset of shock revival. We can, therefore, judge the impact of the numerical resolution and neutrino transport under all conditions typically seen in non-rotating core-collapse simulations. We find excellent qualitative agreement in all GW features and mostly very satisfactory quantitative agreement between simulations using the different transport schemes. Overall, resolution-dependent differences in the hydrodynamic behaviour of low-resolution and high-resolution models turn out to have a greater impact on the GW signals than consequences of the different transport methods. Furthermore, increasing the resolution decreases the discrepancies between models with different neutrino transport

Influence of dietary fat on the fatty acid pattern of muscle and liver lipids in rainbow trout (Sabno gairdneri)

Groups of one year old rainbow trout (Salmo gairdneri) were fed diets supplemented with 13% of rape seed oil, olive oil, linseed oil or sunflower seed oil. The fishes were kept in fresh water of a temperature about 10°C throughout the 5 weeks experimental period. Random samples of fish were taken at 0, 1, 3 and 5 weeks, boneless filets taken from the back and livers were collected for analysis. The composition of the major fatty acids was determined in fats extracted from the diets and the samples of organs. The results showed the effect of the dietary fatty acids on the deposition in liver and filets. In all groups the major fatty acid of the supplemented fat increased in filets and livers already after one week. The increases continued during the feeding period for fat from the filets, whereas the livers showed the most pronounced increases after one week, followed by moderate increases or even a decrease after 3 and 5 weeks on the diets. There was a corresponding decrease in the percentage values for all other fatty acids except those which are synthesized from the dietary acids or from the metabolic pool. Linoleic and linolenic acids, which are polar (mobile) acids, increased more rapidly and to higher percentage values than the less polar monoene acids of chain length 20 and 22

Impact of Molecular Architecture and Adsorption Density on Adhesion of Mussel-Inspired Surface Primers with Catechol-Cation Synergy.

Marine mussels secrete proteins rich in residues containing catechols and cationic amines that displace hydration layers and adhere to charged surfaces under water via a cooperative binding effect known as catechol-cation synergy. Mussel-inspired adhesives containing paired catechol and cationic functionalities are a promising class of materials for biomedical applications, but few studies address the molecular adhesion mechanism(s) of these materials. To determine whether intramolecular adjacency of these functionalities is necessary for robust adhesion, a suite of siderophore analog surface primers was synthesized with systematic variations in intramolecular spacing between catechol and cationic functionalities. Adhesion measurements conducted with a surface forces apparatus (SFA) allow adhesive failure to be distinguished from cohesive failure and show that the failure mode depends critically on the siderophore analog adsorption density. The adhesion of these molecules to muscovite mica in an aqueous electrolyte solution demonstrates that direct intramolecular adjacency of catechol and cationic functionalities is not necessary for synergistic binding. However, we show that increasing the catechol-cation spacing by incorporating nonbinding domains results in decreased adhesion, which we attribute to a decrease in the density of catechol functionalities. A mechanism for catechol-cation synergy is proposed based on electrostatically driven adsorption and subsequent binding of catechol functionalities. This work should guide the design of new adhesives for binding to charged surfaces in saline environments

Antihydrogen formation dynamics in a multipolar neutral anti-atom trap

Antihydrogen production in a neutral atom trap formed by an octupole-based magnetic field minimum is demonstrated using field-ionization of weakly bound anti-atoms. Using our unique annihilation imaging detector, we correlate antihydrogen detection by imaging and by field-ionization for the first time. We further establish how field-ionization causes radial redistribution of the antiprotons during antihydrogen formation and use this effect for the first simultaneous measurements of strongly and weakly bound antihydrogen atoms. Distinguishing between these provides critical information needed in the process of optimizing for trappable antihydrogen. These observations are of crucial importance to the ultimate goal of performing CPT tests involving antihydrogen, which likely depends upon trapping the anti-atom

Nicolaus Heimen (*ca.1606/1608 - † nach 1658), ein Bildschnitzer im Herzogtum Schleswig-Holstein-Gottorf

Nicolaus Heimen (ca.1606/08 - nach 1658), ein Bildschnitzer im Herzogtum Schleswig-Holstein-Gottorf Über Leben und Werk Nicolaus Heimen, gibt es nur lückenhafte Belege. Eine umfassende monographische Behandlung seines Gesamtwerk hatte bislang gefehlt. Heimen stammt wahrscheinlich aus Lunden/Dithm. und hat dort wohl auch seine erste Werkstatt eingerichtet (1634/35 Epitaph Kraißbach). Etwa 10 Jahre später taucht der Schnitzer in Schleswig auf, nahe der herzoglichen Residenz Gottorf. Ein Sterbedatum ist nicht bekannt; angenommen wird "nach 1658" (Epitaph Schnel). Eine Liste der Werke Heimens lässt sich nur mit Hilfe der Stilkritik erfassen. Sein Hauptwerk, das Retabel in St. Annen/Dithm., ist auf 1642 datiert. In der Schleswiger Zeit sind eine Reihe herzoglicher Aufträge (1649-55) belegt. Schließlich ist das Retabel in Struxdorf/Schleswig (1655/56) archivalisch gesichert. Die Renaissance hatte das Ädikula-Motiv mit seinen tektonischen Elementen (tragende Stützen – lastendes Gebälk – aufgesetzter Giebel) zu neuem Leben erweckt. Dieses Motiv fand bald auch Eingang in die Darstellende Kunst und in das Repertoire von Bildschnitzern, die es zur Konstruktion ihrer Schauwänden einsetzten. Dabei sind u.a. Beschlag- und Rollwerk bevorzugte Ornamentformen gewesen. Diese formsprachlichen Elemente gehörten bis weit ins 17.Jh. hinein zum Standardrepertoire der Bildschnitzer. Als Erster hatte Heimen jedwede Andeutung von Tragwerk aus seinem Epitaph Kraißbach (1635) verbannt und sämtliche Freiflächen mit quirligem Ohrmuschelwerk überzogen. Letzteres wird zum typischen Ornament im Werk Heimen

Search For Trapped Antihydrogen

We present the results of an experiment to search for trapped antihydrogen atoms with the ALPHA antihydrogen trap at the CERN Antiproton Decelerator. Sensitive diagnostics of the temperatures, sizes, and densities of the trapped antiproton and positron plasmas have been developed, which in turn permitted development of techniques to precisely and reproducibly control the initial experimental parameters. The use of a position-sensitive annihilation vertex detector, together with the capability of controllably quenching the superconducting magnetic minimum trap, enabled us to carry out a high-sensitivity and low-background search for trapped synthesised antihydrogen atoms. We aim to identify the annihilations of antihydrogen atoms held for at least 130 ms in the trap before being released over ~30 ms. After a three-week experimental run in 2009 involving mixing of 10^7 antiprotons with 1.3 10^9 positrons to produce 6 10^5 antihydrogen atoms, we have identified six antiproton annihilation events that are consistent with the release of trapped antihydrogen. The cosmic ray background, estimated to contribute 0.14 counts, is incompatible with this observation at a significance of 5.6 sigma. Extensive simulations predict that an alternative source of annihilations, the escape of mirror-trapped antiprotons, is highly unlikely, though this possibility has not yet been ruled out experimentally.Comment: 12 pages, 7 figure

A high-efficiency spin-resolved phototemission spectrometer combining time-of-flight spectroscopy with exchange-scattering polarimetry

We describe a spin-resolved electron spectrometer capable of uniquely efficient and high energy resolution measurements. Spin analysis is obtained through polarimetry based on low-energy exchange scattering from a ferromagnetic thin-film target. This approach can achieve a similar analyzing power (Sherman function) as state-of-the-art Mott scattering polarimeters, but with as much as 100 times improved efficiency due to increased reflectivity. Performance is further enhanced by integrating the polarimeter into a time-of-flight (TOF) based energy analysis scheme with a precise and flexible electrostatic lens system. The parallel acquisition of a range of electron kinetic energies afforded by the TOF approach results in an order of magnitude (or more) increase in efficiency compared to hemispherical analyzers. The lens system additionally features a 90{\deg} bandpass filter, which by removing unwanted parts of the photoelectron distribution allows the TOF technique to be performed at low electron drift energy and high energy resolution within a wide range of experimental parameters. The spectrometer is ideally suited for high-resolution spin- and angle-resolved photoemission spectroscopy (spin-ARPES), and initial results are shown. The TOF approach makes the spectrometer especially ideal for time-resolved spin-ARPES experiments.Comment: 16 pages, 11 figure