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Estimating Hydrodynamic Quantities In The Presence Of Microscopic Fluctuations, Alejandro Garcia
Estimating Hydrodynamic Quantities In The Presence Of Microscopic Fluctuations, Alejandro Garcia
Alejandro Garcia
This paper discusses the evaluation of hydrodynamic variables in the presence of spontaneous fluctuations, such as in molecular simulations of fluid flows. The principal point is that hydrodynamic variables such as fluid velocity and temperature must be defined in terms of mechanical variables such as momentum and energy density). Because these relations are nonlinear and because fluctuations of mechanical variables are correlated, care must be taken to avoid introducing a bias when evaluating means, variances, and correlations of hydrodynamic variables. The unbiased estimates are formulated; some alternative, incorrect approaches are presented as cautionary warnings. The expressions are verified by numerical …
Hydrodynamic Description Of The Adiabatic Piston, Alejandro Garcia, Malek M. Mansour
Hydrodynamic Description Of The Adiabatic Piston, Alejandro Garcia, Malek M. Mansour
Alejandro Garcia
A closed macroscopic equation for the motion of the two-dimensional adiabatic piston is derived from standard hydrodynamics. It predicts a damped oscillatory motion of the piston towards a final rest position, which depends on the initial state. In the limit of large piston mass, the solution of this equation is in quantitative agreement with the results obtained from both hard disk molecular dynamics and hydrodynamics. The explicit forms of the basic characteristics of the piston’s dynamics, such as the period of oscillations and the relaxation time, are derived. The limitations of the theory’s validity, in terms of the main system …
Validation Of Water Flux And Body Composition In Glaucous Gulls (Larus Hyperboreus), Scott A. Shaffer, Gabrielsen, G.W., Verreault, J, Costa, D.P
Validation Of Water Flux And Body Composition In Glaucous Gulls (Larus Hyperboreus), Scott A. Shaffer, Gabrielsen, G.W., Verreault, J, Costa, D.P
Scott A. Shaffer
Water influx rates (WIR) measured with tritiated water dilution were compared with direct measures of water and energy intake in glaucous gulls (Larus hyperboreus). Total body water (TBW) measured isotopically was also compared with TBW determined by body composition analysis (BCA) of the same birds. Seventeen wild gulls were captured and studied in outdoor enclosures at Ny-Ålesund, Svalbard, in July 2002. Gulls were hand-fed known quantities of Arctic cod (Boreogadus saida) or given water on the basis of one of four experimental treatments: (A) fasting, (B) fish only, (C) water only, or (D) fish and water. Water and energy content …
A Database For The Study Of Marine Mammal Behavior: Gap Analysis, Data Standardization, And Future Directions, Scott A. Shaffer, D P. Costa
A Database For The Study Of Marine Mammal Behavior: Gap Analysis, Data Standardization, And Future Directions, Scott A. Shaffer, D P. Costa
Scott A. Shaffer
A relational database that contained published information on the diving behavior and/or movement patterns of marine mammals was compiled to facilitate a modeling effort of the Effects of Sound on the Marine Environment (ESME) program. A total of 448 references from reports, books, and peer-reviewed journal articles were obtained. The metadata describing each animal studied, location of the study, and equipment used were entered into the database as well as empirical data describing the diving behavior and movement patterns of each animal. In total, the database contained 1815 entries from 51 different marine mammal species or subspecies. The majority of …
Interpolation Of Tracking Data In A Fluid Environment, Y Tremblay, Scott A. Shaffer, S L. Fowler, C E. Kuhn, B I. Mcdonald, M J. Weise, C -A Bost, H Weimerskirch, D E. Crocker, M E. Goebel, D P. Costa
Interpolation Of Tracking Data In A Fluid Environment, Y Tremblay, Scott A. Shaffer, S L. Fowler, C E. Kuhn, B I. Mcdonald, M J. Weise, C -A Bost, H Weimerskirch, D E. Crocker, M E. Goebel, D P. Costa
Scott A. Shaffer
Interpolation of geolocation or Argos tracking data is a necessity for habitat use analyses of marine vertebrates. In a fluid marine environment, characterized by curvilinear structures, linearly interpolated track data are not realistic. Based on these two facts, we interpolated tracking data from albatrosses, penguins, boobies, sea lions, fur seals and elephant seals using six mathematical algorithms. Given their popularity in mathematical computing, we chose Bézier, hermite and cubic splines, in addition to a commonly used linear algorithm to interpolate data. Performance of interpolation methods was compared with different temporal resolutions representative of the less-precise geolocation and the more-precise Argos …