74 research outputs found
Charge radii and electromagnetic moments of 195-211At
Hyperfine-structure parameters and isotope shifts of At195-211 have been measured for the first time at CERN-ISOLDE, using the in-source resonance-ionization spectroscopy method. The hyperfine structures of isotopes were recorded using a triad of experimental techniques for monitoring the photo-ion current. The Multi-Reflection Time-of-Flight Mass Spectrometer, in connection with a high-resolution electron multiplier, was used as an ion-counting setup for isotopes that either were affected by strong isobaric contamination or possessed a long half-life; the ISOLDE Faraday cups were used for cases with high-intensity beams; and the Windmill decay station was used for short-lived, predominantly α-decaying nuclei. The electromagnetic moments and changes in the mean-square charge radii of the astatine nuclei have been extracted from the measured hyperfine-structure constants and isotope shifts. This was only made possible by dedicated state-of-the-art large-scale atomic computations of the electronic factors and the specific mass shift of atomic transitions in astatine that are needed for these extractions. By comparison with systematics, it was possible to assess the reliability of the results of these calculations and their ascribed uncertainties. A strong deviation in the ground-state mean-square charge radii of the lightest astatine isotopes, from the trend of the (spherical) lead isotopes, is interpreted as the result of an onset of deformation. This behavior bears a resemblance to the deviation observed in the isotonic polonium isotopes. Cases for shape coexistence have been identified in At197,199, for which a significant difference in the charge radii for ground (9/2-) and isomeric (1/2+) states has been observed
Inverse odd-even staggering in nuclear charge radii and possible octupole collectivity in $^217,218,219At revealed by in-source laser spectroscopy
International audienceHyperfine-structure parameters and isotope shifts for the 795-nm atomic transitions in At have been measured at CERN-ISOLDE, using the in-source resonance-ionization spectroscopy technique. Magnetic dipole and electric quadrupole moments, and changes in the nuclear mean-square charge radii, have been deduced. A large inverse odd-even staggering in radii, which may be associated with the presence of octupole collectivity, has been observed. Namely, the radius of the odd-odd isotope At has been found to be larger than the average of its even- neighbors, At. The discrepancy between the additivity-rule prediction and experimental data for the magnetic moment of At also supports the possible presence of octupole collectivity in the considered nuclei
Teaching accountability: Using client feedback to train effective family therapists
The AAMFT Task Force on Core Competencies (Nelson et al., 2007) proposed that marriage and family therapy (MFT) educators teach and provide evidence of trainee competence beyond coursework and accrued clinical hours. This article describes the integration of a systematic client feedback protocol into an MFT-accredited program\u27s curricula to address the call for outcome-based learning. Outcome management (OM) provides a framework for teaching and assessing trainee effectiveness. Continuous incorporation of client feedback embodies collaborative, strengths-based, integrative, and diversity-centered program values. Students learn a system for being accountable to clients, the profession, and service communities. © 2011 American Association for Marriage and Family Therapy
The importance of the patient voice in vaccination and vaccine safety—are we listening?
Much has been written about the patient-physician relationship over the years. This relationship is essential in maintaining trust in the complex arena of modern diagnostic techniques, treatment and prevention, including vaccines and vaccine safety. However, a great deal of this material was written from the viewpoint of clinicians and academics. The patient voice may be positive or negative, fragmented or complex. Information sources are weighed and treated differently, according to the value system and risk perceptions of the individual. In post-trust societies, when people have less confidence in health authorities, communication needs to be more than a paternalistic top-down process. Notions of empowerment and individual patient choice are becoming crucial in medical care. The 'voice of the patient', which includes healthy individuals receiving vaccines, needs to be heard, considered and addressed. With respect to childhood immunizations, this will be the voice of the parent or caregiver. The key to addressing any concerns could be to listen more and to develop a communication style that is trust-based and science-informed. Regulatory agencies are encouraging clinical and patient-reported outcomes research under the umbrella of personalized medicine, and this is an important step forward. This paper attempts to reflect the paradigm shift towards increasing attention to the patient voice in vaccination and vaccine safety. (C) 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved
Electrochemical imaging of fusion pore openings by electrochemical detector arrays
Opening of individual exocytotic fusion pores in chromaffin cells was imaged electrochemically with high time resolution. Electrochemical detector arrays that consist of four platinum microelectrodes were microfabricated on a glass coverslip. Exocytosis of single vesicles containing catecholamines from a cell positioned on top of the array is detected by the individual electrodes as a time-resolved oxidation current, reflecting the time course of arrival of catecholamine molecules at the electrode surfaces. The signals exhibit low noise and reveal foot signals indicating fusion pore formation and expansion. The position of individual release events is determined from the fraction of catecholamines recorded by the individual electrodes. Simultaneous fluorescence imaging of release of acridine orange from individual vesicles confirmed the electrochemical position assignments. This electrochemical camera provides very high time resolution, spatiotemporal localization of individual fusion pore openings and quantitative data on the flux of transmitter from individual vesicles. Analysis of the amperometric currents employing random walk simulations indicates that the time course of amperometric spikes measured near the cell surface is due to a low apparent diffusion coefficient of cat-echolamines near the cell surface and not due to slow dissociation from the granular matrix
High-pressure flow reactor: design and application to pertinent oil recovery studies
Continuing studies on combustion cell reactor experiments are expected to promote a better understanding of the problems and mechanisms involved in laboratory investigations and field applications of the in-situ combustion process for enhanced oil recovery. A new high-pressure flow reactor has been designed for analyzing the specific features of in situ combustion in consolidated core materials (real core) at elevated pressures. The purpose of this facility is to enable physical simulation of the in-situ combustion process and air injection process for oil recovery at reservoir conditions of temperature and pressure. This paper describes in detail the high-pressure flow cell reactor facility in terms of specific equipment operation and features. Furthermore, the results of some experiments are presented
Nuclear deformation in the A≈100 region: Comparison between new masses and mean-field predictions
An extension of the atomic mass surface in the region A≈100 was performed via measurements of the Sr and Rb masses with the ion-trap spectrometer ISOLTRAP at CERN-ISOLDE, including the first direct mass determination of Sr and Rb. These measurements confirm the continuation of the region of deformation with the increase of neutron number, at least as far as . To interpret the deformation in the strontium isotopic chain and to determine whether an onset of deformation is present in heavier krypton isotopes, a comparison is made between the experimental values and mean-field and beyond mean-field results available in the literature. To complete this comparison Hartree-Fock-Bogoliubov calculations for even and odd isotopes were performed, illustrating the competition of nuclear shapes in the region
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