Second release of the CoRe database of binary neutron star merger waveforms

We present the second data release of gravitational waveforms from binaryneutron star merger simulations performed by the Computational Relativity(CoRe) collaboration. The current database consists of 254 different binaryneutron star configurations and a total of 590 individual numerical-relativitysimulations using various grid resolutions. The released waveform data containthe strain and the Weyl curvature multipoles up to $\ell=m=4$. They span asignificant portion of the mass, mass-ratio,spin and eccentricity parameterspace and include targeted configurations to the events GW170817 and GW190425.CoRe simulations are performed with 18 different equations of state, seven ofwhich are finite temperature models, and three of which account fornon-hadronic degrees of freedom. About half of the released data are computedwith high-order hydrodynamics schemes for tens of orbits to merger; the otherhalf is computed with advanced microphysics. We showcase a standard waveformerror analysis and discuss the accuracy of the database in terms offaithfulness. We present ready-to-use fitting formulas for equation ofstate-insensitive relations at merger (e.g. merger frequency), luminosity peak,and post-merger spectrum.<br

Electrochemical Behaviour of Cu-Al Oxygen-Evolving Anodes in Low-Temperature Fluoride Melts and Suspensions

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Cu-based alloys have been considered as promising candidates (along with the Fe-Ni alloys) for the inert anodes material in aluminium reduction cells with low-temperature electrolytes. However, low purity of aluminium due to the contamination by anode corrosion products is a problem yet to be solved. Introduction of alumina suspension as an electrolyte has been presented recently as a possible solution for providing commercial purity aluminium produced with the metallic anode. An attempt to characterize the CuAl-based anodes electrochemical performance in KF-AlF3-Al2O3 melts and suspensions has been made and presented. The effects of the suspension (or melt) properties, the anode composition and the temperature on the electrochemical behaviour of the anode and the kinetics of the oxide layer formation during polarization are studied. The 90Cu-10Al anode in the KF-AlF3-Al2O3 suspension with the cryolite ratio 1.3 and the dispersed phase volume fraction not more than 0.12 is found to be the good option for further investigations. © 2020, The Minerals, Metals & Materials Society

Инертные аноды в алюминиевой промышленности: обзор

The paper is a review of the advancements achieved towards the research work done towards inert anodes for aluminium reduction cell. The research work dedicated towards inert anodes has been for more than a century, but significant advancement was made only a few decades ago. The aim of the researchers was to find the anode which shows excellent electrical conductivity and highly resistant towards corrosion with longer anodic lifetime but this is highly difficult to achieve. This article reviews the research work done on: (1) Ceramics, which are oxides of Ni, Sn, Fe, and Cu which can be one or a combination of oxides e.g. NiO – Li2O (2) Metals, in pure or alloy form (3) Cermets, oxides in combination with the metals. Some results obtained in laboratory scale cells were highly liable and gave a scope to try them on industrial cellsВ статье представлен обзор достижений в разработке инертного анода для алюминиевого электролизера. Исследования, посвященные инертным анодам, проводятся более века, но значительные успехи достигнуты всего несколько десятилетий назад. Целью исследователей была разработка анода с высокими электропроводностью и коррозионной устойчивостью во фторидных расплавах, чего на практике весьма трудно достичь. В этой статье рассмотрены исследования, проведенные на: (1) керамических анодах, содержащих оксиды металлов Ni, Sn, Fe и Cu или их комбинации, например, NiO-Li2O; (2) металлах и сплавах (3) керметах, т.е. оксидно- металлических композициях. Некоторые результаты, полученные в лабораторных ячейках, были обнадеживающими и дали возможность проведения промышленных испытани

Инертные аноды в алюминиевой промышленности: обзор

The paper is a review of the advancements achieved towards the research work done towards inert anodes for aluminium reduction cell. The research work dedicated towards inert anodes has been for more than a century, but significant advancement was made only a few decades ago. The aim of the researchers was to find the anode which shows excellent electrical conductivity and highly resistant towards corrosion with longer anodic lifetime but this is highly difficult to achieve. This article reviews the research work done on: (1) Ceramics, which are oxides of Ni, Sn, Fe, and Cu which can be one or a combination of oxides e.g. NiO – Li2O (2) Metals, in pure or alloy form (3) Cermets, oxides in combination with the metals. Some results obtained in laboratory scale cells were highly liable and gave a scope to try them on industrial cellsВ статье представлен обзор достижений в разработке инертного анода для алюминиевого электролизера. Исследования, посвященные инертным анодам, проводятся более века, но значительные успехи достигнуты всего несколько десятилетий назад. Целью исследователей была разработка анода с высокими электропроводностью и коррозионной устойчивостью во фторидных расплавах, чего на практике весьма трудно достичь. В этой статье рассмотрены исследования, проведенные на: (1) керамических анодах, содержащих оксиды металлов Ni, Sn, Fe и Cu или их комбинации, например, NiO-Li2O; (2) металлах и сплавах (3) керметах, т.е. оксидно- металлических композициях. Некоторые результаты, полученные в лабораторных ячейках, были обнадеживающими и дали возможность проведения промышленных испытани

Numerical relativity simulations of prompt collapse mergers: Threshold mass and phenomenological constraints on neutron star properties after GW170817

We determine the threshold mass for prompt (no bounce) black hole formation in equal-mass neutron star (NS) mergers using a new set of 227 numerical relativity simulations. We consider 23 phenomenological and microphysical finite-temperature equations of state (EOS), including models with hyperons and first-order phase transitions to deconfined quarks. We confirm the existence of EOS-insensitive relations between the threshold mass, binary tidal parameter at the threshold (Λth), maximum mass of nonrotating NSs, and radii of reference mass NSs. We combine the EOS-insensitive relations, phenomenological constraints on NS properties, and observational data from GW170817 to derive an improved lower limit on radii of maximum mass and a 1.6 M⊙ NS of 9.81 and 10.90 km, respectively. We also constrain the radius and quadrupolar tidal deformability (Λ) of a 1.4 M⊙ NS to be larger than 10.74 km and 172, respectively. We consider uncertainties in all independent parameters - fitting coefficients as well as GW170817 masses while reporting the range of radii constraints. We discuss an approach to constrain the upper as well as lower limit of NS maximum mass using future binary NS detections and their identification as prompt or delayed collapse. With future observations, it will be possible to derive even tighter constraints on the properties of matter at and above nuclear density using the method proposed in this work