We study an ideal Bose gas of N atoms contained in a box formed by two identical planar and parallel surfaces S , enclosed by a mantle of height a perpendicular to them. Calling r0 the mean atomic distance, we assume S ≫ r 0 , while a may be comparable to r0. In the bidimensional limit (a/r0 ≡ γ << 1) we find a macroscopic number of atoms in the condensate at temperatures T ∼ O(1/ log(N)); ther...

The theory of resonant generation of nonground-state Bose-Einstein condensates is extended to Bose-condensed systems at finite temperature. The generalization is based on the notion of representative statistical ensembles for Bose systems with broken global gauge symmetry. Self-consistent equations are derived describing an arbitrary nonequilibrium nonuniform Bose system. The notion of finite-t...

We report on the study of the momentum distribution of a one-dimensional Bose gas in an optical lattice. From the momentum distribution we extract the condensed fraction of the gas and thereby measure the depletion of the condensate and compare it with a theorical estimate. We have measured the coherence length of the gas for systems with average occupation n̄ > 1 and n̄ < 1 per lattice site. 1 T...

When a thermopile is used to measure the heat production of isolated muscle, the muscle is surrounded by gas saturated with water vapour, initially in equilibrium with the muscle. After contraction, the osmolarity of the muscle is raised so that it is no longer in equilibrium with the gas around it, and condensation will occur. When artificial muscles of known osmolarity were placed on a thermo...

We present the microscopic kinetic theory of a homogeneous dilute Bose condensed gas in the generalized random phase approximation (GRPA), which satisfies the following requirements: 1) the mass, momentum and energy conservation laws; 2) the H-theorem; 3) the superfluidity property and 4) the recovery of the Bogoliubov theory at zero temperature . In this approach, the condensate influences the...

We relate the frequency of the scissors mode to the moment of inertia of a trapped Bose gas at finite temperature in a semi-classical approximation. We apply these theoretical results to the data obtained in our previous study of the properties of the scissors mode of a trapped Bose-Einstein condensate of Rb atoms as a function of the temperature. The frequency shifts that we measured show quen...

Coal power stations as well as waste incinerators produce humid acid gases which condensate in industrial chimneys. These condensates may cause corrosion of the internal cladding made of stainless steels, nickel base alloys or non metallic materials. In the aim of polluting emission reduction and material optimal choice, it is necessary to determine all the phenomena which occur throughout the ...

We study the lengths of the cycles formed by trajectories in the Feynman-Kac representation of the Bose gas. We discuss the occurrence of infinite cycles and their relation to Bose-Einstein condensation.

Gas adsorption and capillary condensation of organic vapors are studied by optical interferometry, using anodized nanoporous alumina films with controlled geometry (cylindrical pores with diameters in the range of 10-60 nm). The optical response of the film is optimized with respect to the geometric parameters of the pores, for potential performance as a gas sensor device. The average thickness...

Supersonic separators have found extensive applications in dehumidification of natural gases since 2003. Unlike previous studies, which have investigated the inlet conditions and nozzle geometry of supersonic separators for pure fluids, the present study employed a combination of momentum, heat, and mass transfer equations along with Virial equation of state (EOS) to inspect the effect of inlet...