55,691 research outputs found
Innovation in services: corporate culture and investment banking
The article discusses service innovation in the investment banking industry. Service industry innovations differ from innovations in industries that produce physical products because they rarely have intellectual property and patent protections. However, investment banking services are typically a series of interrelated businesses such as consulting, wealth management and accounting, and innovations require a business wide coordinated approach. The authors argue that a strong corporate culture can support rather than hinder innovation. The creation of such a culture requires strong leadership and an emphasis on innovation in hiring and promotions
Search for resonances in positron-atom systems
No one likes to see a scattering cross section curve that is too smooth; it is much more interesting to find bumps and wiggles and most interesting if it is possible to understand their cause. Several types of resonances were clearly established in positron-containing systems: those lying just below a degenerate threshold (like 2s-2p in hydrogenic atoms or ions) and those representing Coulomb bound states in a rearranged channel (like Ps + H reversing positron +H(-)). Recently, two new sorts of resonances have been reported for which the resonant mechanism is not clear. The first is a very low lying resonance in the e-Ps system (obtained by an adiabatic expansion method), and the second is a similarly low lying two channel resonance in the positron -H system (obtained by a close-coupling technique.) These developments encouraged the examination of such systems using the standard methods of stabilization and complex rotation. Most of the results are negative; the low lying resonances in either system are verified. Some indication of new resonances in the e(+)-He(+) system is found; this may be caused by the attraction between Ps in the n=2 state and the He(++) nucleus
Atomic Diffusion and Mixing in Old Stars. III. Analysis of NGC 6397 Stars under New Constraints
We have previously reported on chemical abundance trends with evolutionary
state in the globular cluster NGC 6397 discovered in analyses of spectra taken
with FLAMES at the VLT. Here, we reinvestigate the FLAMES-UVES sample of 18
stars, ranging from just above the turnoff point (TOP) to the red giant branch
below the bump. Inspired by new calibrations of the infrared flux method, we
adopt a set of hotter temperature scales. Chemical abundances are determined
for six elements (Li, Mg, Ca, Ti, Cr, and Fe). Signatures of cluster-internal
pollution are identified and corrected for in the analysis of Mg.
On the modified temperature scales, evolutionary trends in the abundances of
Mg and Fe are found to be significant at the 2{\sigma} and 3{\sigma} levels,
respectively. The detailed evolution of abundances for all six elements agrees
with theoretical isochrones, calculated with effects of atomic diffusion and a
weak to moderately strong efficiency of turbulent mixing. The age of these
models is compatible with the external determination from the white dwarf
cooling sequence. We find that the abundance analysis cannot be reconciled with
the strong turbulent-mixing efficiency inferred elsewhere for halo field stars.
A weak mixing efficiency reproduces observations best, indicating a
diffusion-corrected primordial lithium abundance of log {\epsilon}(Li) = 2.57
+- 0.10. At 1.2{\sigma}, this value agrees well with WMAP-calibrated Big-Bang
nucleosynthesis predictions.Comment: 14 pages, 5 figures, accepted by Ap
Method for detecting surface motions and mapping small terrestrial or planetary surface deformations with synthetic aperture radar
A technique based on synthetic aperture radar (SAR) interferometry is used to measure very small (1 cm or less) surface deformations with good resolution (10 m) over large areas (50 km). It can be used for accurate measurements of many geophysical phenomena, including swelling and buckling in fault zones, residual, vertical and lateral displacements from seismic events, and prevolcanic swelling. Two SAR images are made of a scene by two spaced antennas and a difference interferogram of the scene is made. After unwrapping phases of pixels of the difference interferogram, surface motion or deformation changes of the surface are observed. A second interferogram of the same scene is made from a different pair of images, at least one of which is made after some elapsed time. The second interferogram is then compared with the first interferogram to detect changes in line of sight position of pixels. By resolving line of sight observations into their vector components in other sets of interferograms along at least one other direction, lateral motions may be recovered in their entirety. Since in general, the SAR images are made from flight tracks that are separated, it is not possible to distinguish surface changes from the parallax caused by topography. However, a third image may be used to remove the topography and leave only the surface changes
Stability of Few-Charge Systems in Quantum Mechanics
We consider non-relativistic systems in quantum mechanics interacting through
the Coulomb potential, and discuss the existence of bound states which are
stable against spontaneous dissociation into smaller atoms or ions. We review
the studies that have been made of specific mass configurations and also the
properties of the domain of stability in the space of masses or inverse masses.
These rigorous results are supplemented by numerical investigations using
accurate variational methods. A section is devoted to systems of three
arbitrary charges and another to molecules in a world with two
space-dimensions.Comment: 101 pages, review articl
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