Calculation Of Pressure Rise And Energy Of Hot Gases Due To High Energy Arcing Faults In The Metal-clad Switchgear

This paper presents the 3-D CFD calculation results of the pressure rise due to the High Energy Arcing Faults (HEAFs) in the metal-clad switchgears. The calculations were performed considering the came-off of the roof panel that was observed in the arc tests. The calculated pressure development approximately agreed with the measured one. Furthermore, the energy of hot gases exhausted from the broken roof panel was calculated to investigate the thermal effect of hot gases

Ab initio calculations of neutrinoless ββ\beta \beta decay refine neutrino mass limits

Neutrinos are perhaps the most elusive known particles in the universe. We know they have some nonzero mass, but unlike all other particles, the absolute scale remains unknown. In addition, their fundamental nature is uncertain; they can either be their own antiparticles or exist as distinct neutrinos and antineutrinos. The observation of the hypothetical process of neutrinoless double-beta ($0\nu\beta\beta$) decay would at once resolve both questions, while providing a strong lead in understanding the abundance of matter over antimatter in our universe. In the scenario of light-neutrino exchange, the decay rate is governed by, and thereby linked to the effective mass of the neutrino via, the theoretical nuclear matrix element (NME). In order to extract the neutrino mass, if a discovery is made, or to assess the discovery potential of next-generation searches, it is essential to obtain accurate NMEs for all isotopes of experimental interest. However, two of the most important cases, $^{130}$Te and $^{136}$Xe, lie in the heavy region and have only been accessible to phenomenological nuclear models. In this work we utilize powerful advances in ab initio nuclear theory to compute NMEs from the underlying nuclear and weak forces driving this decay, including the recently discovered short-range component. We find that ab initio NMEs are generally smaller than those from nuclear models, challenging the expected reach of future ton-scale searches as well as claims to probe the inverted hierarchy of neutrino masses. With this step, ab initio calculations with theoretical uncertainties are now feasible for all isotopes relevant for next-generation $0\nu\beta\beta$ decay experiments.Comment: 5 pages, 3 figures, supplemental material include

NEU3 (sialidase 3 (membrane sialidase))

Review on NEU3 (sialidase 3 (membrane sialidase)), with data on DNA, on the protein encoded, and where the gene is implicated

Converged ab initio calculations of heavy nuclei

We propose a novel storage scheme for three-nucleon (3N) interaction matrix elements relevant for the normal-ordered two-body approximation used extensively in ab initio calculations of atomic nuclei. This scheme reduces the required memory by approximately two orders of magnitude, which allows the generation of 3N interaction matrix elements with the standard truncation of $E_{3\max}=28$, well beyond the previous limit of 18. We demonstrate that this is sufficient to obtain ground-state energies in $^{132}$Sn converged to within a few MeV with respect to the $E_{3\max}$ truncation. In addition, we study the asymptotic convergence behavior and perform extrapolations to the un-truncated limit. Finally, we investigate the impact of truncations made when evolving free-space 3N interactions with the similarity renormalization group. We find that the contribution of blocks with angular momentum $J_{\rm rel}>9/2$ is dominated by a basis-truncation artifact which vanishes in the large-space limit, so these computationally expensive components can be neglected. For the two sets of nuclear interactions employed in this work, the resulting binding energy of $^{132}$Sn agrees with the experimental value within theoretical uncertainties. This work enables converged ab initio calculations of heavy nuclei.Comment: 13 pages, 10 figure