247 research outputs found
Observations on the Habits of Tabanidae
Author Institution: Department of Entomology, University of New Hampshire, Durha
TB24: The Caddisflies (Trichoptera) of Maine Excepting the Family Hydroptilidae
A survey of the Trichoptera taken from light trap collections made during July and August, 1959, form the basis of the present paper. A checklist of the family Hydroptilidae known from Maine has been published. The collections were made for the most part in the Boreal Region of Maine.https://digitalcommons.library.umaine.edu/aes_techbulletin/1163/thumbnail.jp
The Einstein relation generalized to non-equilibrium
The Einstein relation connecting the diffusion constant and the mobility is
violated beyond the linear response regime. For a colloidal particle driven
along a periodic potential imposed by laser traps, we test the recent
theoretical generalization of the Einstein relation to the non-equilibrium
regime which involves an integral over measurable velocity correlation
functions
Hydroptilidae (Trichoptera) of America north of Mexico, Station Bulletin, no.509
The Bulletin is a publication of the New Hampshire Agricultural Experiment Station, College of Life Sciences and Agriculture, University of New Hampshire, Durham, New Hampshire
Finite sampling effects on generalized fluctuation-dissipation relations for steady states
We study the effects of the finite number of experimental data on the
computation of a generalized fluctuation-dissipation relation around a
nonequilibrium steady state of a Brownian particle in a toroidal optical trap.
We show that the finite sampling has two different effects, which can give rise
to a poor estimate of the linear response function. The first concerns the
accessibility of the generalized fluctuation-dissipation relation due to the
finite number of actual perturbations imposed to the control parameter. The
second concerns the propagation of the error made at the initial sampling of
the external perturbation of the system. This can be highly enhanced by
introducing an estimator which corrects the error of the initial sampled
condition. When these two effects are taken into account in the data analysis,
the generalized fluctuation-dissipation relation is verified experimentally
Nonequilibrium Linear Response for Markov Dynamics, II: Inertial Dynamics
We continue our study of the linear response of a nonequilibrium system. This
Part II concentrates on models of open and driven inertial dynamics but the
structure and the interpretation of the result remain unchanged: the response
can be expressed as a sum of two temporal correlations in the unperturbed
system, one entropic, the other frenetic. The decomposition arises from the
(anti)symmetry under time-reversal on the level of the nonequilibrium action.
The response formula involves a statistical averaging over explicitly known
observables but, in contrast with the equilibrium situation, they depend on the
model dynamics in terms of an excess in dynamical activity. As an example, the
Einstein relation between mobility and diffusion constant is modified by a
correlation term between the position and the momentum of the particle
Brownian Carnot engine
The Carnot cycle imposes a fundamental upper limit to the efficiency of a
macroscopic motor operating between two thermal baths. However, this bound
needs to be reinterpreted at microscopic scales, where molecular bio-motors and
some artificial micro-engines operate. As described by stochastic
thermodynamics, energy transfers in microscopic systems are random and thermal
fluctuations induce transient decreases of entropy, allowing for possible
violations of the Carnot limit. Despite its potential relevance for the
development of a thermodynamics of small systems, an experimental study of
microscopic Carnot engines is still lacking. Here we report on an experimental
realization of a Carnot engine with a single optically trapped Brownian
particle as working substance. We present an exhaustive study of the energetics
of the engine and analyze the fluctuations of the finite-time efficiency,
showing that the Carnot bound can be surpassed for a small number of
non-equilibrium cycles. As its macroscopic counterpart, the energetics of our
Carnot device exhibits basic properties that one would expect to observe in any
microscopic energy transducer operating with baths at different temperatures.
Our results characterize the sources of irreversibility in the engine and the
statistical properties of the efficiency -an insight that could inspire novel
strategies in the design of efficient nano-motors.Comment: 7 pages, 7 figure
Free energy of colloidal particles at the surface of sessile drops
The influence of finite system size on the free energy of a spherical
particle floating at the surface of a sessile droplet is studied both
analytically and numerically. In the special case that the contact angle at the
substrate equals a capillary analogue of the method of images is
applied in order to calculate small deformations of the droplet shape if an
external force is applied to the particle. The type of boundary conditions for
the droplet shape at the substrate determines the sign of the capillary
monopole associated with the image particle. Therefore, the free energy of the
particle, which is proportional to the interaction energy of the original
particle with its image, can be of either sign, too. The analytic solutions,
given by the Green's function of the capillary equation, are constructed such
that the condition of the forces acting on the droplet being balanced and of
the volume constraint are fulfilled. Besides the known phenomena of attraction
of a particle to a free contact line and repulsion from a pinned one, we
observe a local free energy minimum for the particle being located at the drop
apex or at an intermediate angle, respectively. This peculiarity can be traced
back to a non-monotonic behavior of the Green's function, which reflects the
interplay between the deformations of the droplet shape and the volume
constraint.Comment: 24 pages, 19 figure
An integrative approach to more nuanced estimates of personality–job–performance relations
This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The data that support the findings of this study are openly available on OSF at https://osf.io/ys72j/?view_only=f48aeaf9414d46fb81019186030afbdcRecent research has suggested that self- and other-ratings of personality may provide different information about personality, which can be captured in the trait–reputation–identity (TRI) model. Based on the TRI model, we investigate the link between personality and aligned job performance criteria on domain and aspect levels of the Big Five personality traits. In five samples (overall N = 571 triplets of target self-ratings and two coworker other-ratings), we investigated the relationships between the shared information on personality and shared information about job performance. We found that all personality domains showed substantial criterion validity in predicting the corresponding job-performance dimensions. Furthermore, we found stronger estimates for aspects of agreeableness and openness. We discuss theoretical and practical implications for target replacement and performance management
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