73,242 research outputs found
N-port rectangular-shaped distributed RC NETWORKS
Dielectric material between resistive thin film and pure conductor considered as n-port distributed RC networ
Synthesis of active distributed RC networks
Open-circuit transfer function of two-port network expressed as rational function with real coefficient
Scatter of elastic waves by a thin flat elliptical inhomogeneity
Elastodynamic fields of a single, flat, elliptical inhomogeneity embedded in an infinite elastic medium subjected to plane time harmonic waves are studied. Scattered displacement amplitudes and stress intensities are obtained in series form for an incident wave in an arbitrary direction. The cases of a penny shaped crack and an elliptical crack are given as examples. The analysis is valid for alpha a up to about two, where alpha is longitudinal wave number and a is a typical geometric parameter
Dynamic moduli and localized damage in composites
The scatter of elastic waves due to a thin, flat ellipsoidal inhomogeneity, either penny shaped or elliptical is discussed. An average theorem appropriate for dynamic effective mass density and effective moduli was developed via a self-consistent scheme. Effective material properties of two-component media consisting of randomly distributed spheres are given here as a special case
The relationship between metabolic rate and sociability is altered by food-deprivation
Individuals vary in the extent to which they associate with conspecifics, but little is known about the energetic underpinnings of this variation in sociability. Group-living allows individuals to find food more consistently, but within groups, there can be competition for food items. Individuals with an increased metabolic rate could display decreased sociability to reduce competition. Long-term food deprivation (FD) may alter any links between sociability and metabolic rate by affecting motivation to find food.
We examined these issues in juvenile qingbo carp Spinibarbus sinensis, to understand how FD and metabolic rate affect sociability. Like many aquatic ectotherms, this species experiences seasonal bouts of FD.
Individuals were either: (i) food-deprived for 21 days; or (ii) fed a maintenance ration (control). Fish from each treatment were measured for standard metabolic rate (SMR) and tested for sociability twice: once in the presence of a control stimulus shoal and once with a food-deprived stimulus shoal.
Control individuals ventured further from stimulus shoals over a 30-min trial, while food-deprived fish did not change their distance from stimulus shoals as trials progressed. Control fish with a higher SMR were least sociable. Well-fed controls showed decreased sociability when exposed to food-deprived stimulus shoals, but there was evidence of consistency in relative sociability between exposures to different shoal types.
Results contrast with previous findings that several days of fasting causes individuals to decrease associations with conspecifics. Prolonged FD may cause individuals to highly prioritize food acquisition, and the decreased vigilance that would accompany continuous foraging may heighten the need for the antipredator benefits of shoaling. Conversely, decreased sociability in well-fed fish with a high SMR probably minimizes intraspecific competition, allowing them to satisfy an increased energetic demand while foraging. Together, these results suggest that FD – a challenge common for many ectothermic species – can affect individual sociability as well as the attractiveness of groups towards conspecifics. In addition, the lack of a link between SMR and sociability in food-deprived fish suggests that, in situations where group membership is linked to fitness, the extent of correlated selection on metabolic traits may be context-dependent
Many-body quantum coherence and interaction blockade in Josephson-linked Bose-Einstein condensates
We study many-body quantum coherence and interaction blockade in two
Josephson-linked Bose-Einstein condensates. We introduce universal operators
for characterizing many-body coherence without limitations on the system
symmetry and total particle number . We reproduce the results for both
coherence fluctuations and number squeezing in {\em symmetric} systems of large
, and reveal several peculiar phenomena that may occur in {\em asymmetric}
systems and systems of small . For asymmetric systems, we show that, due to
an interplay between asymmetry and inter-particle interaction, the coherence
fluctuations are suppressed dramatically when , and both
{\it resonant tunneling} and {\it interaction blockade} take place for large
values of , where and are the interaction and
tunneling energies, respectively. We emphasize that the resonant tunneling and
interaction blockade may allow creating single-atom devices with promising
technology applications. We demonstrate that for the systems at finite
temperatures the formation of self-trapped states causes an anomalous behavior.Comment: 6 pages, 5 figures, accepted for publication in EPL (Europhysics
Letters
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