Search results for " elements"

Voila, a New Drosophila Courtship Variant that Affects the Nervous System: Behavioral, Neural, and Genetic Characterization

1998

InDrosophila melanogaster, a specificPGAL4transposon induces theVoila1genetic variant and produces multiple phenotypes. HomozygousVoila1/1flies rarely reach adulthood, whereas heterozygousVoila1/+adult males show strong bisexual behavior. Males with a single copy ofVoila1driving the feminizing transgeneUAS-transformershow very reduced sexual activity but no overall effect on their behavior.Voila1is specifically expressed in the nervous system. In the CNS, it is expressed mainly in the mushroom bodies and, to a lesser extent, in the antennal lobes. In the peripheral nervous system, GAL4 expression is almost entirely restricted to the gustatory sensilla. Using chromosomal deficiencies, the be…

Preliminary results of trace elements mobility in soils and plants from the active hydrothermal area of Nisyros island (Greece)

2014

HHT-α and TR-BDF2 schemes for dynamic contact problems

2023

This work focuses on the numerical performance of HHT-α and TR-BDF2 schemes for dynamic frictionless unilateral contact problems between an elastic body and a rigid obstacle. Nitsche's method, the penalty method, and the augmented Lagrangian method are considered to handle unilateral contact conditions. Analysis of the convergence of an opposed value of the parameter α for the HHT-α method is achieved. The mass redistribution method has also been tested and compared with the standard mass matrix. Numerical results for 1D and 3D benchmarks show the functionality of the combinations of schemes and methods used.

A review on some discrete variational techniques for the approximation of essential boundary conditions

2022

We review different techniques to enforce essential boundary conditions, such as the (nonhomogeneous) Dirichlet boundary condition, within a discrete variational framework, and especially techniques that allow to account for them in a weak sense. Those are of special interest for discretizations such as geometrically unfitted finite elements or high order methods, for instance. Some of them remain primal, and add extra terms in the discrete weak form without adding a new unknown: this is the case of the boundary penalty and Nitsche techniques. Others are mixed, and involve a Lagrange multiplier with or without stabilization terms. For a simple setting, we detail the different associated for…

Seismic prevention and rehabilitation of nonstructural elements. Application experiences of nonstructural pre-seismic evaluation

2012

Topics concerning nonstructural seismic prevention and rehabilitation take their place in the main context of buildings safety in order to explore some aspects of performance of those technical elements. They have become very topical in Italy in the last decade since the repetition of seismic events has made vulnerability and its implications obvious not only in terms of safety risk. This paper reports briefly about author research experiences in this topic and more detail an experience as a component of research team, organizer and tutor in the activities of an international cooperation project between University of Palermo and University of California-Berkeley. After a short introduction …

The first large-scale shell-model calculation of the two-neutrino double beta decay of $^{76}$Ge to the excited states in $^{76}$Se

2022

Large-scale shell-model calculations were carried out for the half-lives and branching ratios of the $2\nu\beta\beta$ decay of $^{76}$Ge to the ground state and the lowest three excited states $2_1^+$, $0_2^+$ and $2_2^+$ in $^{76}$Se. In total, the wave functions of more than 10,000 intermediate $1^+$ states in $^{76}$As were calculated in a three-step procedure allowing an efficient use of the available computer resources. In the first step, 250 lowest states, below some 5 MeV of excitation energy, were calculated without truncations within a full major shell $0f_{5/2}-1p-0g_{9/2}$ for both protons and neutrons. The wave functions of the rest of the states, up to some 30 MeV, were compute…

Neutrinoless ββ decays to excited 0+ states and the Majorana-neutrino mass

2016

The nuclear matrix elements (NMEs) corresponding to the neutrinoless double-β (0νββ) decays to excited 0+ states of major experimental interest are calculated. All these decay transitions are electron emitting (0νβ−β− decays) and take place in the mass A = 76,82,96,100,110,116,124,130,136 nuclei. This work is an extension of our previous work [Phys. Rev. C 91, 024613 (2015)], where 0νββ decays to the ground states of the same nuclei were treated. We calculate the NMEs for transitions mediated by both the light (l-NMEs) and the heavy (h-NMEs) Majorana neutrinos. A higher-QRPA (quasiparticle random-phase approximation) framework, the multiple-commutator model, is adopted for the calculations,…

MELISSA: Laser ion source setup at CERN-MEDICIS facility. Blueprint

2019

The Resonance Ionization Laser Ion Source (RILIS) has become an essential feature of many radioactive ion beam facilities worldwide since it offers an unmatched combination of efficiency and selectivity in the production of ion beams of many different chemical elements. In 2019, the laser ion source setup MELISSA is going to be established at the CERN-MEDICIS facility, based on the experience of the workgroup LARISSA of the University Mainz and CERN ISOLDE RILIS team. The purpose is to enhance the capability of the radioactive ion beam supply for end users by optimizing the yield and the purity of the final product. In this article, the blueprint of the laser ion source, as well as the key …

Pinning down the strength function for ordinary muon capture on 100Mo

2019

Ordinary muon capture (OMC) on 100Mo is studied both experimentally and theoretically in order to access the weak responses in wide energy and momentum regions. The OMC populates states in 100Nb up to some 50 MeV in excitation energy. For the first time the associated OMC strength function has been computed and compared with the obtained data. The present computations are performed using the Morita-Fujii formalism of OMC by extending the original formalism beyond the leading order. The participant nuclear wave functions are obtained in extended no-core single-particle model space using the spherical version of proton-neutron quasiparticle random-phase approximation (pnQRPA) with two-nucleon…

Production of refractory elements close to the Z=N line using the ion-guide technique

1998

Production of neutron-deficient isotopes of refractory elements in the A = 80-88 region was studied using the IGISOL technique and the 165 MeV Si-32 + Ni-nat reaction. Radioactive isotopes of Y through Mo could be produced up to the M-T = + 1 line. New information on the decay of the A = 82 and 85 nuclei, including a more detailed decay scheme and more accurate half-life for Y-82, was obtained. (C) 1998 Elsevier Science B.V. All rights reserved.