Search results for "Island"

Nuclear ground-state spins and magnetic moments ofMg27,Mg29, andMg31

2008

The ground-state spins and magnetic moments of neutron-rich {sup 27}Mg, {sup 29}Mg, and {sup 31}Mg were measured for the first time with laser and {beta}-NMR spectroscopy at ISOLDE/CERN. The hyperfine structure of {sup 27}Mg--observed in fluorescence--confirms previous assignments of the spin I=1/2 and reveals the magnetic moment {mu}{sub I}({sup 27}Mg)=-0.4107(15){mu}{sub N}. The hyperfine structure and nuclear magnetic resonance of optically polarized {sup 29}Mg--observed in the asymmetry of its {beta} decay after implantation in a cubic crystal--give I=3/2 and {mu}{sub I}({sup 29}Mg)=+0.9780(6){mu}{sub N}. For {sup 31}Mg they yield together I=1/2 and {mu}{sub I}({sup 31}Mg)=-0.88355(15){…

Coulomb excitation of Na-29,Na-30: Mapping the borders of the island of inversion

2014

Seidlitz, M., et all ; 10 pags. ; 9 figs. ; 1 tab. ; PACS number(s): 21.60.Cs, 23.20.Js, 25.70.De, 29.38.Gj

Collectivity of neutron-rich magnesium isotopes investigated by projected shell model calculations

2013

The abnormally large collectivity of neutron-rich magnesium isotopes in the “island of inversion” has not been well understood. It has been commented that the unexpectedly large deformations observed in the magnesium isotopes are attributed to the neutron f7/2 intruder orbits involved remarkably even in the ground states, which points to nuclear force directly. Recently, a new isospin-dependent Nilsson potential was suggested to improve the calculations of the ground states of magnesium isotopes. With the improved Nilsson potential, in the present work we investigate the collectivity of excited states by using the projected shell model. To avoid the collapse of the BCS pairing, which occurs…

Search for superheavy elements in damped collisions betweenU238andCm248

1986

Negative results for the production of superheavy elements in damped collisions between $^{238}\mathrm{U}$ projectiles and $^{248}\mathrm{Cm}$ targets are reported. This reaction was believed to permit a closer and more widespread approach to the predicted island of stability near Z=114 and N=184 than any practical fusion reaction. Aqueous and gas phase chemistry techniques were used to isolate superheavy element fractions. The fractions were counted for spontaneous fission activity, fragment kinetic energies, and neutron multiplicities. Cross-section limits for half-lives from hours to several years are g4\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}35}$ ${\mathrm{cm}}^{…

Spectroscopy of34,35Sibyβdecay:sd−fpshell gap and single-particle states

2001

Precision Mass Measurements of Cr58–63 : Nuclear Collectivity Towards the N=40 Island of Inversion

2018

The neutron-rich isotopes $^{58-63}$Cr were produced for the first time at the ISOLDE facility and their masses were measured with the ISOLTRAP spectrometer. The new values are up to 300 times more precise than those in the literature and indicate significantly different nuclear structure from the new mass-surface trend. A gradual onset of deformation is found in this proton and neutron mid-shell region, which is a gateway to the second island of inversion around \emph{N}=40. In addition to comparisons with density-functional theory and large-scale shell-model calculations, we present predictions from the valence-space formulation of the \emph{ab initio} in-medium similarity renormalization…

Kinetic model for surface reconstruction

2002

Institut fu ¨r Physikalische und Theoretische Chemie, Technische Universitat Braunschweig, Hans-Sommer-Strase 10,38106 Braunschweig, Germany~Received 7 December 2001; published 25 July 2002!A microscopic kinetic model for the ab @e.g., hex131 for Pt~100! and 132131 for Pt~110!#surface reconstruction is investigated by means of the mean field approximation and Monte Carlo simulations.It considers homogeneous phase nucleation that induces small surface phase defects. These defects can grow ordecline via phase border propagation in dependence on the chemical coverage by an adsorbate A ~CO!.Anasymmetry in the adsorbate surface diffusion from one surface phase to the other gives rise to two criti…

Search for elements 119 and 120

2020

A search for production of the superheavy elements with atomic numbers 119 and 120 was performed in the 50Ti+249Bk and 50Ti+249Cf fusion-evaporation reactions, respectively, at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. Over four months of irradiation, the 249Bk target partially decayed into 249Cf, which allowed for a simultaneous search for both elements. Neither was detected at cross-section sensitivity levels of 65 and 200 fb for the 50Ti+249Bk and 50Ti+249Cf reactions, respectively, at a midtarget beam energy of Elab=281.5 MeV. The nonobservation of elements 119 and 120 is discussed within the concept of fusion-evaporation reactions including various theoretical pr…

Piano di Gestione UNESCO Isole EOLIE

2008

Nel Piano di gestione del sito UNESCO Isole Eolie sono definiti i criteri e le modalità per realizzare contemporaneamente l’obiettivo della tutela di un bene e uno sviluppo locale sostenibile. Il Piano contiene una mappatura dei Beni Culturali e Ambientali e Naturalistici, descrivendo un sistema territorio sotto il profilo economico-ambientale che contiene: - L’inquadramento storico, economico e antropologico del sito, l’uso finora fatto, i fattori di incidenza sui beni ambientali e culturali; - L’inquadramento attuale del sito, attraverso un’analisi degli strumenti legislativi e amministrativi e della loro conformità; - L’analisi dei processi produttivi critici e le relative interazioni co…

Genome-wide parent-of-origin DNA methylation analysis reveals the intricacies of human imprinting and suggests a germline methylation-independent mec…

2014

Genomic imprinting is a form of epigenetic regulation that results in the expression of either the maternally or paternally inherited allele of a subset of genes (Ramowitz and Bartolomei 2011). This imprinted expression of transcripts is crucial for normal mammalian development. In humans, loss-of-imprinting of specific loci results in a number of diseases exemplified by the reciprocal growth phenotypes of the Beckwith-Wiedemann and Silver-Russell syndromes, and the behavioral disorders Angelman and Prader-Willi syndromes (Kagami et al. 2008; Buiting 2010; Choufani et al. 2010; Eggermann 2010; Kelsey 2010; Mackay and Temple 2010). In addition, aberrant imprinting also contributes to multige…