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We report a new direct measurement of the transition energy QEC of the 23Mg β+ decay, using the TITAN Penning-trap mass spectrometer. This value is found to agree with the latest atomic mass evaluation while being four times more precise. The increase in precision changes the uncertainty contribution of the QEC value on the statistical rate function ƒV from 11% to 0.6%, an improvement by a factor of 18. This enables a more robust determination of the corrected Ft value of this mirror transition to the required precision, making possible further test of the Cabibbo-Kobayashi-Maskawa matrix unitarity. [ABSTRACT FROM AUTHOR]

The first direct mass measurement of 6He has been performed with the TITAN Penning trap mass spectrometer at the ISAC facility. In addition, the mass of 8He was determined with improved precision over our previous measurement. The obtained masses are m(6He) = 6.018 885 883(57) u and m(8He) = 8.03393444(11) u. The 6He value shows a deviation from the literature of 4cr. With these new mass values and the previously measured atomic isotope shifts we obtain charge radii of 2.060(8) and 1.959 (16) fm for 6He and 8He, respectively. We present a detailed comparison to nuclear theory for 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. [ABSTRACT FROM AUTHOR]

We present Penning-trap mass measurements of neutron-rich 44.47-50K and 49.50Ca isotopes carried out at the TITAN facility at TRIUMF-ISAC. The 44K mass measurement was performed with a charge-bred 4+ ion utilizing the TITAN electron beam ion trap and agrees with the literature. The mass excesses obtained for 47K and 49-50Ca are more precise and agree with the values published in the 2003 Atomic Mass Evaluation (AME'03). The 48,49,50K mass excesses are more precise than the AME'03 values by more than 1 order of magnitude. For 48,49K, we find deviations of 7&rgr; and 10&rgr;, respectively. The new 49K mass excess lowers significantly the two-neutron separation energy at the neutron number N = 30 compared with the separation energy calculated from the AME'03 mass-excess values and thus increases the N = 28 neutron-shell gap energy at Z = 19 by approximately 1 MeV. [ABSTRACT FROM AUTHOR]

Knowledge of 2 νββ nuclear matrix elements is essential to probe the theoretical framework of 0 νββ decays. At TITAN, TRIUMF's Ion Trap for Atomic and Nuclear science, a novel technique has been developed to measure electron capture branches of virtual intermediate nuclei in ββ decays. During two experiments with radioactive Cs isotopes the feasibility of this new method was proven. [ABSTRACT FROM AUTHOR]

This study investigates conceptualizations of disease prevention and health promotion (DPHP) among nurses from local public health organizations in Montréal, Québec. Design and Sample: A collaborative qualitative study was conducted among a purposive sample of 41 nurses. Measures: Semi-structured interviews investigated two themes: meanings attributed to DPHP as well as nurses' recent DPHP activities. Results: Although the meaning attributed to prevention referred to standard definitions, health promotion was often defined as large-scale health education oriented toward the attainment of positive results, such as health and well-being. Almost completely absent from participants' discourse were central notions such as empowerment and health determinants, including socioenvironmental dimensions of health. With regard to activity descriptions, there was a very partial coverage of the full spectrum of DPHP. Participants rarely went beyond traditional health education activities aimed at an individual target. Finally, a sizeable number of participants appeared to be unable to provide a clear distinction between the terms “health promotion” and “prevention.” Conclusions: The results are consistent with a conclusion frequently drawn by commentators and researchers alike that highlight a narrow range of DPHP nursing practices. [ABSTRACT FROM AUTHOR]

Abstract: Penning trap mass measurements of 9Be, 10Be (), and the one-neutron halo nuclide 11Be () have been performed using TITAN at TRIUMF. The resulting 11Be mass excess () is in agreement with the current Atomic Mass Evaluation (AME03) [G. Audi, et al., Nucl. Phys. A 729 (2003) 337] value, but is over an order of magnitude more precise. The precision of the mass values of 9,10Be have been improved by about a factor of four and reveal a deviation from the AME mass values. Results of new atomic physics calculations are presented for the isotope shift of 11Be relative to 9Be, and it is shown that the new mass values essentially remove atomic mass uncertainties as a contributing factor in determining the relative nuclear charge radius from the isotope shift. The new mass values of 10,11Be also allow for a more precise determination of the single-neutron binding energy of the halo neutron in 11Be. [Copyright &y& Elsevier]

Abstract: The mechanisms responsible for the perception of illusory modal figures are usually studied by presenting entire Kanizsa figures at stimulus onset. However, with this mode of presentation, the brain activity generated by the inducers (the ‘pacmen’) is difficult to differentiate from the activity underlying the perception of the illusory figure. Therefore, in addition to this usual presentation mode, we used an alternative presentation mode. Inducer disks remained permanently on the screen and the illusory figure was induced by just removing the notches from the disks. The results support the heuristic value of this alternative mode of presentation. The P1 deflection of the visual evoked potentials (VEPs) was found to be greater for the illusory modal figure than for its control and for an amodal figure. This modulation is one of the earliest direct evidences for a low-level processing of illusory forms in the human brain. Meanwhile, larger N1s were obtained for the control figures than for the illusory figures in the notch mode of presentation. While this new type of N1 modulation could shed some light on the stage of processing indexed by this deflection, several propositions are put forward to account for the P1 and N1 variations found. [Copyright &y& Elsevier]

Describes the findings of a study aimed at improving linen delivery operations in a large teaching hospital in Montreal, Quebec, Canada. How improvements over the previous system were obtained; Utilization of a tabu search algorithm; Implementation of this system at the hospital.

The future N = 126 factory at Argonne National Laboratory is aimed to produce neutron-rich elements around the N = 126 peak of the rapid-neutron capture process using multi-nucleon transfer reactions. However, this radioactive ion beam production method will entail the delivery of contaminant ions. To remove the isobar contaminants from the beam, a multi-reflection time-of-flight mass spectrometer has been built and successfully commissioned at the University of Notre Dame, reaching a resolving power of 70,000, with an efficiency of 10%. According to stability study conducted, the resolving power is potentially limited to 83,000 by the power supply stability, however it can be mitigated by the addition of RC filtration as done for other MR-TOFs. The commissioned MR-TOF has been transported to Argonne National Laboratory to be used in the N = 126 factory. [ABSTRACT FROM AUTHOR]

A new precision half-life measurement of 29P was conducted using the TwinSol β-counting station at the University of Notre Dame Nuclear Science Laboratory. The resulting value of t1/2new=4.1055(44)s is the most precise 29P half-life measurement to date. Utilizing this measurement and reevaluating the world data leads to a new world average of t1/2world=4.1031(58)s, which improves the Birge ratio from 3.11 to 1.45 and is 2.3 times more precise than the previous world value. The new Cabibbo-Kobayashi-Maskawa matrix element Vud for 29P shifts closer into agreement with the superallowed pure Fermi value. The uncertainty in the mixed transition value of Vud, however, is still dominated by the Fermi to Gamow-Teller mixing ratio ρ. Using the new world half-life and assuming the validity of the standard model, a new predicted value for ρ and its associated correlation parameters have been evaluated in order to guide future determination of ρ. [ABSTRACT FROM AUTHOR]

Tests of the unitarity of the Cabbibo-Kobayashi-Masakawa (CKM) matrix offer an important avenue for constraining the Standard Model of the electroweak interaction. Several methods are currently used to determine Vud, the largest element in the top-row normalization test. One such method is through the study of superallowed T = 1/2 mixed mirror transitions, which offers a complementary method to the current most-precise value that is determined from superallowed pure Fermi 0+ → 0+ transitions. The precision currently achievable by this method is currently limited by the very low number of transitions for which the Fermi-to-Gamow-Teller mixing ratio ρ has been measured. St. Benedict, the Superallowed Transition Beta-Neutrino Decay-Ion-Coincidence Trap, is currently under development at the University of Notre Dame's Nuclear Science Laboratory, and intends to determine ρ for a range of new isotopes through measurements of the β-neutrino asymmetry parameter aβν using a linear Paul trap. In order to trap these ions, the fast, continuous secondary beam separated by the TwinSol twin solenoid separator must be thermalized and bunched. The system through which this will be done will feature a large-volume gas cell in which the ions will be thermalized, a double-RF-funnel-based ion guide system for the extraction of the ions, and a radiofrequency quadrupole (RFQ) to provide cooled ion bunches for capture in the Paul trap. [ABSTRACT FROM AUTHOR]

We report a new precision half-life measurement of 20F, performed using the β-counting station of the University of Notre Dame's Nuclear Science Laboratory. The measured half-life of 11.0160(41)stat(155)sys s resulting from this work will help resolve the longstanding discrepancy between two earlier sets of high-precision half-life measurements. [ABSTRACT FROM AUTHOR]

Background: The precise determination of the Ft value in T=1/2 mixed mirror decays is an important avenue for testing the standard model of the electroweak interaction through the determination of Vud in nuclear β decays. 11C is an interesting case, as its low mass and small QEC value make it particularly sensitive to violations of the conserved vector current hypothesis. The present dominant source of uncertainty in the 11CFt value is the half-life. Purpose: A high-precision measurement of the 11C half-life was performed, and a new world average half-life was calculated. Method: 11C was created by transfer reactions and separated using the TwinSol facility at the Nuclear Science Laboratory at the University of Notre Dame. It was then implanted into a tantalum foil, and β counting was used to determine the half-life. Results: The new half-life, t1/2=1220.27(26) s, is consistent with the previous values but significantly more precise. A new world average was calculated, tworld1/2=1220.41(32) s, and a new estimate for the Gamow-Teller to Fermi mixing ratio ρ is presented along with standard model correlation parameters. Conclusions: The new 11C world average half-life allows the calculation of a Ftmirror value that is now the most precise value for all superallowed mixed mirror transitions. This gives a strong impetus for an experimental determination of ρ, to allow for the determination of Vud from this decay. [ABSTRACT FROM AUTHOR]