48,156 research outputs found
Review of Bring on the books for everybody: how literary culture became popular culture by Jim Collins [2010]
Strategy, Core Competence and HR Involvement as Determinants of HR Effectiveness and Refinery Performance
This study examined the impact strategy, core competence, and involvement of HR executives in strategic decision making on the refinery managers\u27 evaluation of the effectiveness of HR and refinery performance among 86 U.S. petro-chemical refineries. Survey results indicated that higher involvement of HR in organizational strategy was strongly related to perceptions of HR effectiveness, and that the relationship was strongest to the extent that refineries pursued a product innovation strategy and viewed skilled employees as their core competence. HR involvement was unrelated to refinery performance, but was actually negatively related to the extent that refineries emphasized efficient production as their core competence
Trapping of light beams and formation of spatial solitary waves in quadratic nonlinear media
Summary form only given. In this paper we report the outcome of our comprehensive investigations to study the dynamics of the beam trapping in both bulk crystals and optical planar waveguides made of quadratic nonlinear media in second-harmonic generation configurations. We address and discuss the suitable experimental conditions required to form spatial solitary waves in critical phase-matching and quasi-phase-matching settings.Peer ReviewedPostprint (published version
The Role of Human Resource Practices in Petro-Chemical Refinery Performance
This study examined the impact of Human Resource (HR) practices (selection, training, compensation, and appraisal) and participation on the financial performance of U.S. petrochemical refineries. Survey results from HR and Operations respondents indicated that appraisal and training were significantly related to workforce skills and that training and compensation were marginally related to workforce motivation. In addition, only training was significantly related to refinery performance, although the relationship was negative. However, selection, compensation, and appraisal interacted with participation in determining refinery financial performance such that each of these practices were strongly positively related to financial performance only under highly participative systems. Implications are discussed
Calcification Studies with Laying Hens
The aim of the present study is to determine whether certain metabolites of vitamin D3 (1,25-dihydroxycholecalciferol or 24,25-dihydroxycholecalciferol) added to the diet will affect shell quality in aged laying hens. This will be further evaluated by measurements of the carbonic anhydrase activity of the shell gland, blood serum calcium levels and calcium binding protein activity of the duodenum and shell gland
Cooperative program for design, fabrication, and testing of graphite/epoxy composite helicopter shafting
The fabrication of UH-1 helicopter tail rotor drive shafts from graphite/epoxy composite materials is discussed. Procedures for eliminating wrinkles caused by lack of precure compaction are described. The development of the adhesive bond between aluminum end couplings and the composite tube is analyzed. Performance tests to validate the superiority of the composite materials are reported
VLA Detection of the Ionized Stellar Winds Arising from Massive Stars in the Galactic Center Arches Cluster
The Galactic center Arches stellar cluster, detected and studied until now
only in the near-infrared, is comprised of at least one hundred massive (M>20
Msun) stars. Here we report the detection at centimeter wavelengths of radio
continuum emission from eight radio sources associated with the cluster. Seven
of these radio sources have rising spectral indices between 4.9 and 8.5 GHz and
coincide spatially with the brightest stars in the cluster, as determine from
JHK photometry and Brackett alpha and Brackett Gamma spectroscopy. Our results
confirm the presence of powerful ionized winds in these stars. The eighth radio
source has a nonthermal spectrum and its nature is yet unclear, but it could be
associated with a lower mass young star in the cluster.Comment: 6 pages, 2 embedded figures, accepted to ApJLetter
Probing the circulation of ring-shaped Bose-Einstein condensates
This paper reports the results of a theoretical and experimental study of how
the initial circulation of ring-shaped Bose-Einstein condensates (BECs) can be
probed by time-of-flight (TOF) images. We have studied theoretically the
dynamics of a BEC after release from a toroidal trap potential by solving the
3D Gross-Pitaevskii (GP) equation. The trap and condensate characteristics
matched those of a recent experiment. The circulation, experimentally imparted
to the condensate by stirring, was simulated theoretically by imprinting a
linear azimuthal phase on the initial condensate wave function. The theoretical
TOF images were in good agreement with the experimental data. We find that upon
release the dynamics of the ring--shaped condensate proceeds in two distinct
phases. First, the condensate expands rapidly inward, filling in the initial
hole until it reaches a minimum radius that depends on the initial circulation.
In the second phase, the density at the inner radius increases to a maximum
after which the hole radius begins slowly to expand. During this second phase a
series of concentric rings appears due to the interference of ingoing and
outgoing matter waves from the inner radius. The results of the GP equation
predict that the hole area is a quadratic function of the initial circulation
when the condensate is released directly from the trap in which it was stirred
and is a linear function of the circulation if the trap is relaxed before
release. These scalings matched the data. Thus, hole size after TOF can be used
as a reliable probe of initial condensate circulation. This connection between
circulation and hole size after TOF will facilitate future studies of
atomtronic systems that are implemented in ultracold quantum gases.Comment: 9 pages, 9 figure
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