263,332 research outputs found
Studies of cycles for liquid-metal magnetohydrodynamic generation of power
Studies of liquid-metal magnetohydrodynamic power cycles indicate that the overall efficiency of a binary cycle, employing a liquid-metal topping cycle and a bottoming steam cycle, may reach 60 percent. Details of analyses and data on cycles are presented, and the commercial potential of the binary cycle is discussed
Contemplating workplace change: evolving individual thought processes and emergent story lines
Drawing on topical life histories of physicians in a particularly volatile public health
sector environment, we build theory around the contemplation of workplace change.
Overall, our study provides evidence as to why single or multiple independent factors,
such as pay or job structure, may fail to predict or explain individual decisions to stay
in or change workplaces. Instead, the contemplation process we argue is a complex,
evolutionary, and context-dependent one that requires individualized interventions.
Our findings reveal the prevalence of episodic context-self fit assessments prompted
by triggering stimuli, two mechanisms by which thought processes evolved
(reinforcement and recalibration), and four characteristic story lines that explain
why the thought processes manifested as they did (exploring opportunities, solving
problems, reconciling incongruence, and escaping situations). Based on our findings,
we encourage practitioners to regularly engage in story-listening and dialogic
conversations to better understand, and potentially affect the evolving socially
constructed realities of staff members
An infrared proper motion study of the Orion bullets
We report the first IR proper motion measurements of the Herbig-Haro objects
in the Orion Molecular Cloud--One using a four-year time baseline. The [Fe II]
emitting bullets are moving of order 0.08 arcsec per year, or at about 170
\kms. The direction of motion is similar to that inferred from their
morphology. The proper motions of \h2 emitting wakes behind the [Fe II]
bullets, and of newly found \h2 bullets, are also measured. \h2 bullets have
smaller proper motion than [Fe II] bullets, while \h2 wakes with leading [Fe
II] bullets appear to move at similar speeds to their associated bullets. A few
instances of variability in the emission can be attributed to dense, stationary
clumps in the ambient cloud being overrun, setting up a reverse--oriented
bullet. Differential motion between [Fe II] bullets and their trailing \h2
wakes is not observed, suggesting that these are not separating, and also that
they have reached a steady--state configuration over at least 100 years. The
most distant bullets have, on average, larger proper motions, but are not
consistent with free expansion. Nevertheless an impulsive, or short--lived
( 1,000 years) duration for their origin seems likely.Comment: 9 pages, 8 figure
Talon cusp affecting primary dentition in two siblings: a case report
The term talon cusp refers to a rare developmental dental anomaly characterized by a cusp-like structure projecting from the cingulum area or cement-enamel junction. This condition can occur in the maxillary and mandibular arches of the primary and permanent dentitions. The purpose of this paper is to report on the presence of talon cusps in the primary dentition of two southern Chinese siblings. The 4 years and 2 months old girl had a talon cusp on her maxillary right primary central incisor, while her 2 years and 9 months old brother had bilateral talon cusps on the maxillary primary central incisors. The presence of this rare dental anomaly in two siblings has scarcely been reported in the literature and this may provide further evidence of a hereditary etiology.Article Link:
http://www.rjme.ro/RJME/resources/files/540113211213.pd
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Gender differences in health-related quality of life following total laryngectomy
Background: The impact of a total laryngectomy on an individual's life has primarily been measured from a male viewpoint reflecting the demographics of a diagnosis of laryngeal cancer. A small number of studies have looked specifically at females, but very few are comparison studies. Consequently, there is little consistent research regarding any potential gender differences.
Aims: To investigate whether there are gender differences in perceptions of health-related quality of life and functional abilities following total laryngectomy.
Methods & Procedures: A total of 43 participants (22 males, 21 females), who had undergone a total laryngectomy procedure at least one year previously, took part in the study. They completed The European Organisation for Research and Treatment of Cancer Core Questionnaire Version 3.0 (EORTC QLQ-C30) in conjunction with the disease-specific Head & Neck Cancer Module (QLQ-H&N35).
Outcomes & Results: There were no significant differences between males and females on demographic and disease-related variables, except for the following: significantly more females lived alone and changed their employment status following surgery. Males had a significantly higher global health status/quality of life than females (p < 0.05) and significantly higher levels of physical (p = 0.01), emotional (p < 0.01), cognitive (p < 0.05) and social functioning (p < 0.05). After adjusting for differences in living arrangements and change in employment status, differences in emotional and social functioning remained significant. There was a general trend for females to have higher symptom/impairment levels and to report more treatment-related problems, but the majority of these differences were not significant.
Conclusions & Implications: Following total laryngectomy, females appear to be worsely affected in aspects of quality of life than males. Emotional and social functioning are particularly vulnerable. The findings imply that rehabilitation programmes after total laryngectomy need to evaluate quality of life and address these specific areas in order to improve patient-reported long-term outcomes
A Generalized Circle Theorem on Zeros of Partition Function at Asymmetric First Order Transitions
We present a generalized circle theorem which includes the Lee-Yang theorem
for symmetric transitions as a special case. It is found that zeros of the
partition function can be written in terms of discontinuities in the
derivatives of the free energy. For asymmetric transitions, the locus of the
zeros is tangent to the unit circle at the positive real axis in the
thermodynamic limit. For finite-size systems, they lie off the unit circle if
the partition functions of the two phases are added up with unequal prefactors.
This conclusion is substantiated by explicit calculation of zeros of the
partition function for the Blume-Capel model near and at the triple line at low
temperatures.Comment: 10 pages, RevTeX. To be published in PRL. 3 Figures will be sent upon
reques
Microscopic picture of aging in SiO2
We investigate the aging dynamics of amorphous SiO2 via molecular dynamics
simulations of a quench from a high temperature T_i to a lower temperature T_f.
We obtain a microscopic picture of aging dynamics by analyzing single particle
trajectories, identifying jump events when a particle escapes the cage formed
by its neighbors, and by determining how these jumps depend on the waiting time
t_w, the time elapsed since the temperature quench to T_f. We find that the
only t_w-dependent microscopic quantity is the number of jumping particles per
unit time, which decreases with age. Similar to previous studies for fragile
glass formers, we show here for the strong glass former SiO2 that neither the
distribution of jump lengths nor the distribution of times spent in the cage
are t_w-dependent. We conclude that the microscopic aging dynamics is
surprisingly similar for fragile and strong glass formers.Comment: 4 pages, 7 figure
Near-field angular distributions of high velocity ions for low-power hall thrusters
Experimental angular distributions of high-energy primary ions in the near-field region of a small Hall thruster between 50-200 mm downstream of the thruster exit plane at a range of centerline angles have been determined using a highly-collimated, energy-selective diagnostic probe. The measurements reveal a wide angular distribution of ions exiting the thruster channel and the formation of a strong, axially-directed jet of ions along the thruster centerline. Comparisons are made to other experimental determinations as applicable
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