Search results for "Penn"
showing 10 items of 568 documents
Chemisorption of hydrogen on charged vanadium clusters
1996
Abstract The chemisorption of hydrogen on positively charged vanadium clusters, V n + ( n = 1–17), was studied by measuring reaction rates and saturation coverages. Vanadium clusters are produced by laser vaporization and are injected into a Penning trap. Rates of the reaction V n + +H 2 → V n + H 2 are measured by axial ejection of all ions out of the trap after variable storage times and subsequent time-of-flight detection. An odd-even effect of the reaction rate is observed with odd clusters being more reactive. Clusters with low reactivity are found to be highly stable, as reflected by the respective separation energies of atoms. The number of adsorbed hydrogen atoms, m , is determined …
Personality traits and unemployment: Evidence from longitudinal data
2012
This study contributes to the literature on how personality is related to labour market success by providing evidence on the relationship between personality traits and unemployment. After accounting for reverse causality and measurement error, our results suggest that higher openness was associated with increased cumulative unemployment at the prime working age. It seems that this connection occurs because individuals with higher openness enter into unemployment spells more frequently – not because their unemployment spells would be particularly long. peerReviewed
Theory of the elliptical Penning trap
2008
Abstract An ideal “Elliptical Penning Trap” is an ideal cylindrically symmetric Penning trap with an additional electrostatic quadrupolar potential ∝ κ ( x 2 − y 2 ) . This configuration is here investigated for arbitrary strength κ of the additional potential. Aside from the decoupled axial motion the system is characterized by a generalized cyclotron and a generalized magnetron frequency. While the former depends only weakly on κ , the magnetron frequency decreases rapidly with increasing κ , vanishing at a maximum value κ max which represents the stability limit for the magnetron motion. Magnetron orbits are elliptical, with their numerical excentricity tending toward unity as κ approa…
Cluster isobars for high-precision mass spectrometry
1991
Doublet mass measurements of the isobars28Si3 and12C7 are performed by use of a Penning trap mass spectrometer and the Fourier transform ion cyclotron resonance (FT-ICR). The carbon and silicon cluster ions are produced by laser ablation. Results of these preliminary measurements are presented.
Crustal Structure of the Seismogenic Volume of the 2010–2014 Pollino (Italy) Seismic Sequence From 3D P- and S-Wave Tomographic Images
2021
A tomographic analysis of Mt. Pollino area (Italy) has been performed using earthquakes recorded in the area during an intense seismic sequence that occurred between 2010 and 2014. 870 local earthquakes with magnitude ranging from 1.8 to 5.0 were selected considering the number of recording stations, the signal quality, and the hypocenter distribution. P- and S-wave arrival times were manually picked and used to compute 3D velocity models through tomographic seismic inversion. The resulting 3D distributions of VP and VS are characterized by high resolution in the central part of the investigated area and from surface to about 10 km below sea level. The aim of the work is to obtain high-qual…
3D structural modeling and restoration of the Apennine-Maghrebian chain in Sicily: Application for non-cylindrical fold-and-thrust belts
2019
International audience; Thirteen seismic reflection profiles and field observations have been used to build a three-dimensional watertight geological model of the sub-surface architecture of the Trapanese carbonate platform unit of the Apennine-Maghrebian chain in the Mt. Kumeta and Mt. Rocca Busambra (NW Sicily, Italy). Either a single step or a two-step thrust-fault deformation model is acceptable on the basis of seismic interpretation but the integration of 3D model reconstruction and 3D geomechanical restoration, validates only the scenario with a single stage of deformation.The 3D model highlights along strike variations of the structural style for the Trapanese unit where pre-existing…
Large Impact of the Decay of Niobium Isomers on the Reactor ν¯e Summation Calculations
2019
Even mass neutron-rich niobium isotopes are among the principal contributors to the reactor antineutrino energy spectrum. They are also among the most challenging to measure due to the refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The beta-intensity distributions of Nb-100gs,Nb-100m and Nb-102gs,Nb-02m beta decays have been determined using the total absorption.-ray spectroscopy technique. The measurements were performed at the upgraded Ion Guide Isotope Separator On-Line facility at the University of Jyvaskyla. Here, the double Penning trap system JYFLTRAP was employed to disentangle the beta decay of the isomeric states. The new data ob…
From service quality in organisations to self-determination at home
2015
Background In our proposed model, family members' perceptions of service quality in organisations improve communication about self-determination. In turn, family perceptions of communication openness have a positive relationship with self-determination attitudes of family members. Finally, these attitudes predict self-determination behaviours of individuals with intellectual disability, as reported by family members. Method We tested this model with a sample of 625 family members (196 using ‘day care services’ and 429 using ‘occupational services’). Results Multi-sample structural equation modelling (SEM) supported the model. Communication and attitudes fully mediated the link from service …
3.Storia, caratteri ed evoluzione dei boschi e dei rimboschimenti di Monte Morello e della Calvana _ 4. La vegetazione di Monte Morello e della Calva…
2016
il lavoro divulgativo espone un'attenta analisi dei caratteri geologici, pedologici, vegetazionale dei due rilievi della Toscana settentrionale, con particolare riferimento ai rimboschimenti storicamente realizzati e alla flora endemica. Il libro è ricco di schemi funzionali, illustrazioni didattiche e di una ricca raccolta fotografica.
I parassitoidi di Leptoglossus occidentalis in Sicilia e nel suo areale di origine nordamericano
2011
Sul coreide Leptoglossus occidentalis, cimice delle conifere di origine nordamericana, che in Italia ha fatto registrare un calo della produzione di pinoli di Pinus pinea, si sono finora registrati parassitoidi di ninfe e adulti, e parassitoidi oofagi. Al primo gruppo appartengono i Diptera Tachinidae: negli USA e in Canada è stata riscontrata Trichopoda pennipes, mentre nell’Italia centro-settentrionale pochi adulti sono stati parassitizzati da Ectophasia crassipennis e da tachinidi ancora non identificati. Tra i parassitoidi oofagi in Canada erano stati finora segnalati il Platygastridae Gryon pennsylvanicum, l’Eupelmidae Anastatus pearsalli e l'Encyrtidae Ooencyrtus sp.; nell’Italia cent…