19,249 research outputs found
Integrating Employment Contracts and Comparisons: What One Can Teach Us about the Other
This study examines the events that trigger individuals to consider the social exchanges involved in their employment relationships. Integrating social comparison and psychological contract literature streams, a parallel is drawn between system-referent comparisons and psychological contract evaluations. We hypothesize that self- and other-referent comparisons may be human triggers for engaging in this type of comparison. A variety of structural triggers are also proposed to influence psychological contract evaluations. This field study examines these primary and secondary contract makers as social comparison triggers. Results support the hypotheses that the triggers identified predict psychological contract evaluation and that psychological contract breach is correlated with these evaluations. Implications for future research and managerial practice are discussed
Mixed Meson Masses with Domain-Wall Valence and Staggered Sea Fermions
Mixed action lattice calculations allow for an additive lattice spacing
dependent mass renormalization of mesons composed of one sea and one valence
quark, regardless of the type of fermion discretization methods used in the
valence and sea sectors. The value of the mass renormalization depends upon the
lattice actions used. This mixed meson mass shift is an important lattice
artifact to determine for mixed action calculations; because it modifies the
pion mass, it plays a central role in the low energy dynamics of all hadronic
correlation functions. We determine the leading order, , and
next to leading order, , additive mass shift of
\textit{valence-sea} mesons for a mixed lattice action with domain-wall valence
fermions and rooted staggered sea fermions, relevant to the majority of current
large scale mixed action lattice efforts. We find that on the asqtad improved
coarse MILC lattices, this additive mass shift is well parameterized in lattice
units by , which in physical
units, using fm, corresponds to . In terms of the mixed action effective field
theory parameters, the corresponding mass shift is given by at leading order plus
next-to-leading order corrections including the necessary chiral logarithms for
this mixed action calculation, determined in this work. Within the precision of
our calculation, one can not distinguish between the full next-to-leading order
effective field theory analysis of this additive mixed meson mass shift and the
parameterization given above.Comment: 28 pages, 3 figures, 5 table
Northrop F-5F shark nose development
During spin susceptibility testing of the Northrop F-5F airplane, two erect spin entries were obtained from purely longitudinal control inputs at low speed. Post flight analysis of the data showed that the initial yaw departure occurred at zero sideslip, and review of wind tunnel data showed significant yawing moments present at angles of attack well above stall. Further analysis of this wind tunnel data indicated that the yawing moments were being generated by the long slender nose of the airplane. Redesign of the nose was accomplished, resulting in a nose configuration which completely alleviated the asymmetric yawing moments
Global cross-over dynamics of single semiflexible polymers
We present a mean-field dynamical theory for single semiflexible polymers
which can precisely capture, without fitting parameters, recent fluorescence
correlation spectroscopy results on single monomer kinetics of DNA strands in
solution. Our approach works globally, covering three decades of strand length
and five decades of time: it includes the complex cross-overs occurring between
stiffness-dominated and flexible bending modes, along with larger-scale
rotational and center-of-mass motion. The accuracy of the theory stems in part
from long-range hydrodynamic coupling between the monomers, which makes a
mean-field description more realistic. Its validity extends even to short,
stiff fragments, where we also test the theory through Brownian hydrodynamics
simulations.Comment: 6 pages, 5 figures; updated with minor changes to reflect published
versio
Characterisation of small defects using miniaturised EMAT system
Many surface breaking defects, such as those caused by thermal fatigue or stress corrosion, have finite lateral dimensions. However, much of the research considers significantly larger simulated defects. This paper considers defects with mm-dimensions, and presents a method for characterisation of their length and depth. This is done using non-contact ultrasonic techniques, including a pair of electromagnetic acoustic transducers (EMATs) with significantly reduced size compared to standard industrial EMATs. Defects with dimensions of 1–11 mm length and 0.5–2 mm depth are measured. All information is obtained from a single raster scan of a sample, considering transmission and enhancement of Rayleigh waves, and introducing the defect cross-section. The lateral size resolution for the scan steps chosen is
±
1 mm, and depth resolution is
±
0.5 mm. The method, being non-contact, is also demonstrated on a sample with a 110 μm thick coating
An eighth-century inscribed cross-slab in Dull, Perthshire
The discovery of a cross-inscribed slab with an inscription is described. Because of its importance it was decided to invite specialist comment on this piece of sculpture and to publish it in advance of the full report on the excavations. The form of the monument, its inscription and archaeological context are considered. The text appears to consist of a Gaelic personal name. The script is a form of geometrical lettering which can be dated to the opening quarter of the eighth century. The form of the cross has Columban associations which sit well with place-name and other evidence which points to Dull having been a monastery founded from Iona by c. AD 700
Spontaneous flow states in active nematics: a unified picture
Continuum hydrodynamic models of active liquid crystals have been used to
describe dynamic self-organising systems such as bacterial swarms and
cytoskeletal gels. A key prediction of such models is the existence of
self-stabilising kink states that spontaneously generate fluid flow in
quasi-one dimensional channels. Using simple stability arguments and numerical
calculations we extend previous studies to give a complete characterisation of
the phase space for both contractile and extensile particles (ie pullers and
pushers) moving in a narrow channel as a function of their flow alignment
properties and initial orientation. This gives a framework for unifying many of
the results in the literature. We describe the response of the kink states to
an imposed shear, and investigate how allowing the system to be polar modifies
its dynamical behaviour.Comment: 6 pages, 6 figures; submitted to Europhysics Letter
Parametrization of the Driven Betatron Oscillation
An AC dipole is a magnet which produces a sinusoidally oscillating dipole
field and excites coherent transverse beam motion in a synchrotron. By
observing this coherent motion, the optical parameters can be directly measured
at the beam position monitor locations. The driven oscillation induced by an AC
dipole will generate a phase space ellipse which differs from that of the free
oscillation. If not properly accounted for, this difference can lead to a
misinterpretation of the actual optical parameters, for instance, of 6% or more
in the cases of the Tevatron, RHIC, or LHC. The effect of an AC dipole on the
linear optics parameters is identical to that of a thin lens quadrupole. By
introducing a new amplitude function to describe this new phase space ellipse,
the motion produced by an AC dipole becomes easier to interpret. Beam position
data taken under the influence of an AC dipole, with this new interpretation in
mind, can lead to more precise measurements of the normal Courant-Snyder
parameters. This new parameterization of the driven motion is presented and is
used to interpret data taken in the FNAL Tevatron using an AC dipole.Comment: 8 pages, 8 figures, and 1 tabl
V. problem presentation and advice-giving on a home birth helpline
The rate of home births in the UK is very low (around 2%) and many women who would like to give birth at home find it impossible to get midwifery cover or are advised of medical contraindications. The Home Birth Helpline offers support and expertise for women in this situation. Based on the analysis of 80 recorded calls, this article uses conversation analysis (CA) to explore how callers present their reason for calling the helpline, and what this shows about the culturally shared medicalized culture of birth. This research is an example of feminist CA in that it contributes both to the study of childbirth as a key women's health issue and to the study of helpline interaction from a conversation analytic perspectiv
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