Recently it has become possible to achieve radical manipulation of surface wettability, and wettability is known to play a key role in the retention of condensate and frost melt on heat exchanger surfaces. In this paper we present a review of methods to produce such surfaces, and we describe a super-hydrophobic surface, with a contact angle of 148°, created in our lab. We describe surfaces with...

We demonstrate control of the collapse and expansion of an (88)Sr Bose-Einstein condensate using an optical Feshbach resonance near the (1)S(0)-(3)P(1) intercombination transition at 689 nm. Significant changes in dynamics are caused by modifications of scattering length by up to ± 10a(bg), where the background scattering length of (88)Sr is a(bg) = -2a(0) (1a(0) = 0.053 nm). Changes in scatter...

REFERENCES 1 Rosias PP, Jobsis Q, van de Kant K, et al. Global condensation: a ‘‘climate change’’ towards better standardisation of exhaled breath condensate measurements. Eur Respir J 2008; 31: 684–685. 2 Liu J, Conrad DH, Chow S, Tran VH, Yates DH, Thomas PS. Collection devices influence the constituents of exhaled breath condensate. Eur Respir J 2007; 30: 807–808. 3 Prieto L, Ferrer A, Palop...

A condensate of p = 0 partons in the perturbative vacuum gives rise to a term ∝ δ(p) in the free PQCD propagators. The leading condensate contribution to the quark propagator can be exactly summed since there is a factor δ(p) associated to each loop. We calculate the dressed quark propagator in the presence of either a gluon or a quark condensate, for a number of colors N → ∞. The dressed quark...

We present neutron scattering measurements of Bose–Einstein condensation (BEC) in liquid 4He adsorbed in thick layers on an MgO substrate to study whether the condensate fraction, n0, is increased near a free surface of liquid 4He. The data show that there is definitely a condensate in the layers adsorbed on the substrate with a condensate fraction comparable to that of bulk liquid 4He. Two met...

We investigate the zero-temperature properties of an impurity particle interacting with a Bose-Einstein condensate (BEC), using a variational wave function that includes up to two Bogoliubov excitations of the BEC. This allows one to capture three-body Efimov physics, as well as to recover the first nontrivial terms in the weak-coupling expansion. We show that the energy and quasiparticle resid...

We report on the experimental observation of vortex tangles in an atomic Bose-Einstein condensate (BEC) of ;{87}Rb atoms when an external oscillatory perturbation is introduced in the trap. The vortex tangle configuration is a signature of the presence of a turbulent regime in the cloud. We also show that this turbulent cloud suppresses the aspect ratio inversion typically observed in quantum d...

We observe solitonic vortices in an atomic Bose-Einstein condensate (BEC) after free expansion. Clear signatures of the nature of such defects are the twisted planar density depletion around the vortex line, observed in absorption images, and the double dislocation in the interference pattern obtained through homodyne techniques. Both methods allow us to determine the sign of the quantized circ...

We evaluate the Bose-Einstein condensate density and the superfluid fraction of bosons in a periodic external potential using Path-Integral Monte Carlo (PIMC) methods. The periodic lattice consists of a cubic cell containing a potential well that is replicated along 1D using periodic boundary conditions. The aim is to describe bosons in a 1D optical lattice or helium confined in a periodic poro...