121 research outputs found
Electron-correlation effects in the -factor of light Li-like ions
We investigate electron-correlation effects in the -factor of the ground
state of Li-like ions. Our calculations are performed within the
nonrelativistic quantum electrodynamics (NRQED) expansion up to two leading
orders in the fine-structure constant , and . The
dependence of the NRQED results on the nuclear charge number is studied and
the individual -expansion contributions are identified. Combining the
obtained data with the results of the all-order (in ) calculations
performed within the expansion, we derive the unified theoretical
predictions for the -factor of light Li-like ions.Comment: 9 pages, 4 table
Coefficients of Friction for Apple on Various Surfaces as Affected by Velocity
Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a Technical Paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 5 (2003): C. Puchalski, G. Brusewitz, and Z. Slipek. Coefficients of Friction for Apple on Various Surfaces as Affected by Velocity. Vol. V. December 2003
Self-energy screening effects in the factor of Li-like ions
We report an investigation of the self-energy screening effects for the
factor of the ground state of Li-like ions. The leading screening contribution
of the relative order is calculated to all orders in the binding nuclear
strength parameter (where is the nuclear charge number and
is the fine-structure constant). We also extend the known results for
the expansion of the QED screening correction by deriving the leading
logarithmic contribution of order and obtaining approximate
results for the and contributions. The comparison of the
two approaches yields a stringent check of consistency of the two calculations
and allows us to obtain improved estimations of the higher-order screening
effects.Comment: Several misprints are corrected in ver.3; Sec. VI is updated in ver.
Isotope Shift Measurements of Stable and Short-Lived Lithium Isotopes for Nuclear Charge Radii Determination
Changes in the mean-square nuclear charge radii along the lithium isotopic
chain were determined using a combination of precise isotope shift measurements
and theoretical atomic structure calculations. Nuclear charge radii of light
elements are of high interest due to the appearance of the nuclear halo
phenomenon in this region of the nuclear chart. During the past years we have
developed a new laser spectroscopic approach to determine the charge radii of
lithium isotopes which combines high sensitivity, speed, and accuracy to
measure the extremely small field shift of an 8 ms lifetime isotope with
production rates on the order of only 10,000 atoms/s. The method was applied to
all bound isotopes of lithium including the two-neutron halo isotope Li-11 at
the on-line isotope separators at GSI, Darmstadt, Germany and at TRIUMF,
Vancouver, Canada. We describe the laser spectroscopic method in detail,
present updated and improved values from theory and experiment, and discuss the
results.Comment: 34 pages, 24 figures, 14 table
Redefining Palliative Care-A New Consensus-Based Definition.
The International Association for Hospice and Palliative Care developed a consensus-based definition of palliative care (PC) that focuses on the relief of serious health-related suffering, a concept put forward by the Lancet Commission Global Access to Palliative Care and Pain Relief.
The main objective of this article is to present the research behind the new definition.
The three-phased consensus process involved health care workers from countries in all income levels. In Phase 1, 38 PC experts evaluated the components of the World Health Organization definition and suggested new/revised ones. In Phase 2, 412 International Association for Hospice and Palliative Care members in 88 countries expressed their level of agreement with the suggested components. In Phase 3, using results from Phase 2, the expert panel developed the definition.
The consensus-based definition is as follows: Palliative care is the active holistic care of individuals across all ages with serious health-related suffering due to severe illness and especially of those near the end of life. It aims to improve the quality of life of patients, their families and their caregivers. The definition includes a number of bullet points with additional details as well as recommendations for governments to reduce barriers to PC.
Participants had significantly different perceptions and interpretations of PC. The greatest challenge faced by the core group was trying to find a middle ground between those who think that PC is the relief of all suffering and those who believe that PC describes the care of those with a very limited remaining life span
Redefining palliative care-a new consensus-based definition
Context: The International Association for Hospice and Palliative Care developed a consensus-based definition of palliative care (PC) that focuses on the relief of serious health-related suffering, a concept put forward by the Lancet Commission Global Access to Palliative Care and Pain Relief.
Objective: The main objective of this article is to present the research behind the new definition.
Methods: The three-phased consensus process involved health care workers from countries in all income levels. In Phase 1, 38 PC experts evaluated the components of the World Health Organization definition and suggested new/revised ones. In Phase 2, 412 International Association for Hospice and Palliative Care members in 88 countries expressed their level of agreement with the suggested components. In Phase 3, using results from Phase 2, the expert panel developed the definition.
Results: The consensus-based definition is as follows: Palliative care is the active holistic care of individuals across all ages with serious health-related suffering due to severe illness and especially of those near the end of life. It aims to improve the quality of life of patients, their families and their caregivers. The definition includes a number of bullet points with additional details as well as recommendations for governments to reduce barriers to PC.
Conclusion: Participants had significantly different perceptions and interpretations of PC. The greatest challenge faced by the core group was trying to find a middle ground between those who think that PC is the relief of all suffering and those who believe that PC describes the care of those with a very limited remaining life span
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