The theory of generalized Taylor dispersion for suspensions of Brownian particles is developed to study the dispersion of gyrotactic swimming micro-organisms in a linear shear flow. Such creatures are bottom-heavy and experience a gravitational torque which acts to right them when they are tipped away from the vertical. They also suffer a net viscous torque in the presence of a local vorticity ...

We report on the status of emittance tuning techniques at the CESR Test Accelerator (CesrTA). The CesrTA experimental program requires that we operate in a variety of machine lattices, each with the smallest possible emittance. We utilize high-bandwidth BPM electronics for fast, precision measurements of orbit, betatron phase, transverse coupling, and dispersion. Analysis of the data and implem...

[1] We use kinematic and diabatic back trajectory calculations, driven by winds from a general circulation model (GCM) and two different data assimilation systems (DAS), to compute the age spectrum at three latitudes in the lower stratosphere. The age spectra are compared to chemical transport model (CTM) calculations, and the mean ages from all of these studies are compared to observations. Th...

The recently described trait-based approach is becoming widely popular for a mechanistic understanding of species coexistence. However, the greatest challenge in functional analyses is decomposing the contributions of different ecological and evolutionary processes (e.g., niche-based process, neutral process, and evolutionary process) in determining trait structure. Taking rodents (Rodentia) in...

air pollution is one of the most challengeable problems in the asalouyeh zone. in order to reduce the air pollutants emission and their effects it is necessary to recognize the amount and spatial dispersion of air pollutants. hence in this paper, evaporative losses of the stored liquids from 16 tanks of an oil company in asalouyeh zone, are determined using tanks 4.0.9d and then dispersion of v...

Context. The vertical thickness of debris discs is often used as a measure of these systems’ dynamical excitation, and as clues to the presence of hidden massive perturbers such as planetary embryos. However, this argument might be flawed because the observed dust should be naturally placed on inclined orbits by the combined effect of radiation pressure and mutual collisions. Aims. We criticall...

the purpose of this paper is to present a 2d depth-averaged model for simulating and examining unsteady flow patterns in open channel bends. in particular, this paper proposes a 2d depth-averaged model that takes into account the influence of the secondary flow phenomenon through calculation of the dispersion stresses. the dispersion terms which arose from the integration of the product of the ...

The solar f-mode is a surface gravity wave which high horizontal wavenumber k and the frequency ω satisfy the dispersion relation ω2 = gk, where g is the surface gravity of the Sun. However, the observations of this mode revealed deviations from this simple dispersion relation. According to these observations for high values of k the f-mode frequency is significantly lower than the frequency gi...

We observe unique dynamics of Raman soliton during supercontinuum process when an input pulse experiences initially normal group-velocity dispersion with a negative dispersion slope. In this situation, the blue components of the spectrum form a Raman soliton that moves faster than the input pulse and eventually decelerates because of Raman-induced frequency downshifting. In the time domain, the...