645 research outputs found

    Highly charged ions in Penning traps, a new tool for resolving low lying isomeric states

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    The use of highly charged ions increases the precision and resolving power, in particular for short-lived species produced at on-line radio-isotope beam facilities, achievable with Penning trap mass spectrometers. This increase in resolving power provides a new and unique access to resolving low-lying long-lived (T1/2>50T_{1/2} > 50 ms) nuclear isomers. Recently, the 111.19(22)111.19(22) keV (determined from γ\gamma-ray spectroscopy) isomeric state in 78^{78}Rb has been resolved from the ground state, in a charge state of q=8+q=8+ with the TITAN Penning trap at the TRIUMF-ISAC facility. The excitation energy of the isomer was measured to be 108.7(6.4)108.7(6.4) keV above the ground state. The extracted masses for both the ground and isomeric states, and their difference, agree with the AME2003 and Nuclear Data Sheet values. This proof of principle measurement demonstrates the feasibility of using Penning trap mass spectrometers coupled to charge breeders to study nuclear isomers and opens a new route for isomer searches.Comment: 8 pages, 6 figure

    First direct mass-measurement of the two-neutron halo nucleus 6He and improved mass for the four-neutron halo 8He

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    The first direct mass-measurement of 6^{6}He has been performed with the TITAN Penning trap mass spectrometer at the ISAC facility. In addition, the mass of 8^{8}He was determined with improved precision over our previous measurement. The obtained masses are mm(6^{6}He) = 6.018 885 883(57) u and mm(8^{8}He) = 8.033 934 44(11) u. The 6^{6}He value shows a deviation from the literature of 4σ\sigma. With these new mass values and the previously measured atomic isotope shifts we obtain charge radii of 2.060(8) fm and 1.959(16) fm for 6^{6}He and 8^{8}He respectively. We present a detailed comparison to nuclear theory for 6^6He, including new hyperspherical harmonics results. A correlation plot of the point-proton radius with the two-neutron separation energy demonstrates clearly the importance of three-nucleon forces.Comment: 4 pages, 2 figure

    Sustaining Clinician Penetration, Attitudes and Knowledge in Cognitive-Therapy for Youth Anxiety

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    Background: Questions remain regarding the sustainment of evidence-based practices following implementation. The present study examined the sustainment of community clinicians’ implementation (i.e., penetration) of cognitive-behavioral therapy, attitudes toward evidence-based practices, and knowledge of cognitive-behavioral therapy for youth anxiety two years following training and consultation in cognitive-behavioral therapy for youth anxiety. Methods: Of the original 115 participants, 50 individuals (43%) participated in the two-year follow-up. A t- test examined sustainment in penetration over time. Hierarchical linear modeling examined sustainment in knowledge and attitudes over time. Time spent in consultation sessions was examined as a potential moderator of the change in knowledge and attitudes. Results: Findings indicated sustained self-reported penetration of cognitive-behavioral therapy for anxious youth, with low fidelity to some key CBT components (i.e., exposure tasks). Follow-up knowledge was higher than at baseline but lower than it had been immediately following the consultation phase of the study. Belief in the utility of evidence-based practices was sustained. Willingness to implement an evidence-based practice if required to do so, appeal of evidence-based practices, and openness toward evidence-based practices were not sustained. Participation in consultation positively moderated changes in knowledge and some attitudes. Conclusions: Sustainment varied depending on the outcome examined. Generally, greater participation in consultation predicted greater sustainment. Implications for future training include higher dosages of consultation

    Tourism destination competitiveness: second thoughts on the world economic forum reports

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    The Travel and Tourism Competitiveness Reports of the World Economic Forum elaborate the Travel and Tourism Competitiveness Index (TTCI) as an overall measure of destination competitiveness for 130 economies worldwide. From a tourism management point of view, a measure such as the TTCI is expected to be instrumental in explaining and predicting the tourism performance of receiving countries. This study explores several ways to transform the TTCI into a formative structural model. Partial least squares path modelling, PLS regression, mixture modelling and non-linear covariance-based structural equation modelling are applied to examine the TTCI's predictive power. The analysis probes possible measures for improvement. The destination countries may be subject to unobserved heterogeneity with regard to how the various constituents of competitiveness act on tourism performance. Interaction phenomena seem to prohibit a simple cause-effect pattern and non-linear relationships show encouraging results

    Trapped-ion decay spectroscopy towards the determination of ground-state components of double-beta decay matrix elements

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    A new technique has been developed at TRIUMF's TITAN facility to perform in-trap decay spectroscopy. The aim of this technique is to eventually measure weak electron capture branching ratios (ECBRs) and by this to consequently determine GT matrix elements of ββ\beta\beta decaying nuclei. These branching ratios provide important input to the theoretical description of these decays. The feasibility and power of the technique is demonstrated by measuring the ECBR of 124^{124}Cs.Comment: 9 pages, 9 figure

    The effect of personality traits and knowledge on the quality of decisions in supply chains

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    Supply chain and operations management requires frequent decision making, and decisions are importantly influenced by the personality traits and knowledge of the decision maker. Thus, we analyse the effect of those factors on the confidence and quality of decisions taken in the context of supply chain management. The data were gathered via an online supply chain simulation game where subjects needed to make several decisions. Personality traits of the participants were tested using the Big Five model. The structural model was estimated using the partial least squares structural equation modelling approach. We found that decision-makers with lower levels of extraversion and agreeableness and higher levels of conscientiousness and openness make better decisions. On the other hand, neuroticism and agreeableness negatively affect confidence in decisions. Tested knowledge positively influences both decision-makers’ confidence in and the quality of their decisions while self-reported knowledge has no significant effect. Therefore, the companies should carefully consider how an individual’s personality matches the type of job at hand and rely on tested instead of self-reported knowledge
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