424 research outputs found
A stochastic model of the influence of buffer gas collisions on Mollow spectra
In this paper we consider the influence of collisional fluctuations on the
Mollow spectra of resonance fluorescence (RF). The fluctuations are taken into
account by a simple shift of the constant detuning, involved in a set of
optical Bloch equations by collision frequency noise which is modelled by a
two-step random telegraph signal (RTS). We consider in detail the Mollow
spectra for RF in the case of an arbitrary detuning of the laser frequency,
where the emitter is a member of a statistical ensemble in thermodynamic
equilibrium with the buffer gas at temperature which is treated as a
colored environment, and velocity is distributed with the Maxwell-Boltzmann
density
THE DEVELOPMENT AND APPLICATION OF THE ECO-HYDRODYNAMIC AND ENVIRONMENTAL MODELING SYSTEM FOR THE ESTUARINE AND COASTAL AREAS OF VIETNAM
Joint Research on Environmental Science and Technology for the Eart
Microstructural characterization of a Canadian oil sand
The microstructure of oil sand samples extracted at a depth of 75 m from the
estuarine Middle McMurray formation (Alberta, Canada) has been investigated by
using high resolution 3D X-Ray microtomography (CT) and Cryo Scanning
Electron Microscopy (CryoSEM). CT images evidenced some dense areas
composed of highly angular grains surrounded by fluids that are separated by
larger pores full of gas. 3D Image analysis provided in dense areas porosity
values compatible with in-situ log data and macroscopic laboratory
determinations, showing that they are representative of intact states. CT
hence provided some information on the morphology of the cracks and disturbance
created by gas expansion. The CryoSEM technique, in which the sample is freeze
fractured within the SEM chamber prior to observation, provided pictures in
which the (frozen) bitumen clearly appears between the sand grains. No evidence
of the existence of a thin connate water layer between grains and the bitumen,
frequently mentioned in the literature, has been obtained. Bitumen appears to
strongly adhere to the grains, with some grains completely being coated. The
curved shape of some bitumen menisci suggests a bitumen wet behaviour
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