5,084 research outputs found
Traversable Wormholes in Geometries of Charged Shells
We construct a static axisymmetric wormhole from the gravitational field of
two charged shells which are kept in equilibrium by their electromagnetic
repulsion. For large separations the exterior tends to the Majumdar-Papapetrou
spacetime of two charged particles. The interior of the wormhole is a
Reissner-Nordstr\"om black hole matching to the two shells. The wormhole is
traversable and connects to the same asymptotics without violation of energy
conditions. However, every point in the Majumdar-Papapetrou region lies on a
closed timelike curve.Comment: 9 pages, LaTeX, 1 figur
String Supported Wormhole Spacetimes and Causality Violations
We construct a static axisymmetric wormhole from the gravitational field of
two Schwarzschild particles which are kept in equilibrium by strings (ropes)
extending to infinity. The wormhole is obtained by matching two
three-dimensional timelike surfaces surrounding each of the particles and thus
spacetime becomes non-simply connected. Although the matching will not be exact
in general it is possible to make the error arbitrarily small by assuming that
the distance between the particles is much larger than the radius of the
wormhole mouths. Whenever the masses of the two wormhole mouths are different,
causality violating effects will occur.Comment: 12 pages, LaTeX, 1 figur
More than a cognitive experience: unfamiliarity, invalidation, and emotion in organizational learning
Literature on organizational learning (OL) lacks an integrative framework that captures the emotions involved as OL proceeds. Drawing on personal construct theory, we suggest that organizations learn where their members reconstrue meaning around questions of strategic significance for the organization. In this 5-year study of an electronics company, we explore the way in which emotions change as members perceive progress or a lack of progress around strategic themes. Our framework also takes into account whether OL involves experiences that are familiar or unfamiliar and the implications for emotions. We detected similar patterns of emotion arising over time for three different themes in our data, thereby adding to OL perspectives that are predominantly cognitive in orientation
Psychological Safety and Norm Clarity in Software Engineering Teams
In the software engineering industry today, companies primarily conduct their
work in teams. To increase organizational productivity, it is thus crucial to
know the factors that affect team effectiveness. Two team-related concepts that
have gained prominence lately are psychological safety and team norms. Still,
few studies exist that explore these in a software engineering context.
Therefore, with the aim of extending the knowledge of these concepts, we
examined if psychological safety and team norm clarity associate positively
with software developers' self-assessed team performance and job satisfaction,
two important elements of effectiveness.
We collected industry survey data from practitioners (N = 217) in 38
development teams working for five different organizations. The result of
multiple linear regression analyses indicates that both psychological safety
and team norm clarity predict team members' self-assessed performance and job
satisfaction. The findings also suggest that clarity of norms is a stronger
(30\% and 71\% stronger, respectively) predictor than psychological safety.
This research highlights the need to examine, in more detail, the
relationship between social norms and software development. The findings of
this study could serve as an empirical baseline for such, future work.Comment: Submitted to CHASE'201
Developing specialist leaders of education: a research engagement approach
There has been little research to date on the continuing professional
development needs of the several thousand Specialist Leaders of
Education (SLE) now designated by the National College for Teaching
and Leadership in England to work across schools as consultants on
school-to-school support. This case study reports on the second and
third stages of a four-stage research process designed to address these
needs. The
fi
rst stage reported on the creation of a professional devel-
opment framework for SLE
â
s using consultancy research. These middle
stages test out this framework with a stakeholder group of SLEs, head-
teachers and broker in a Teaching Schools Alliance. The fourth stage will
track the implementation of professional development activities arising
from these
fi
ndings. Apart from the speci
fi
c needs of SLE, this study will
have wider relevance for all practitioners and researchers working in and
with schools on leadership development using Research Engagement
strategies and Joint Practice Development approaches in a so-called
â
self-
improving
â
school system
Temperature and Field Dependence of the Mobility in Liquid-Crystalline Conjugated Polymer Films
The transport properties of organic light-emitting diodes in which the
emissive layer is composed of conjugated polymers in the liquid-crystalline
phase have been investigated. We have performed simulations of the current
transient response to an illumination pulse via the Monte Carlo approach, and
from the transit times we have extracted the mobility of the charge carriers as
a function of both the electric field and the temperature. The transport
properties of such films are different from their disordered counterparts, with
charge carrier mobilities exhibiting only a weak dependence on both the
electric field and temperature. We show that for spatially ordered polymer
films, this weak dependence arises for thermal energy being comparable to the
energetic disorder, due to the combined effect of the electrostatic and thermal
energies. The inclusion of spatial disorder, on the other hand, does not alter
the qualitative behaviour of the mobility, but results in decreasing its
absolute value.Comment: 9 pages, 8 figures, submitted to Phys. Rev.
The Problem of Purity in Moral Psychology
Academic AbstractThe idea of ?purity? transformed moral psychology. Here, we provide the first systematic review of this concept. Although often discussed as one construct, we reveal ~9 understandings of purity, ranging from respecting God to not eating gross things. This striking heterogeneity arises because purity?unlike other moral constructs?is not understood by what it is but what it isn?t: obvious interpersonal harm. This poses many problems for moral psychology and explains why purity lacks convergent and divergent validity and why purity is confounded with politics, religion, weirdness, and perceived harm. Because purity is not a coherent construct, it cannot be a distinct basis of moral judgment or specially tied to disgust. Rather than a specific moral domain, purity is best understood as a loose set of themes in moral rhetoric. These themes are scaffolded on cultural understandings of harm?the broad, pluralistic harm outlined by the Theory of Dyadic Morality
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