Collective modes in multicomponent condensates with anisotropy

We report the effects of anisotropy in the confining potential on two component Bose-Einstein condensates (TBECs) through the properties of the low energy quasiparticle excitations. Starting from generalized Gross Pitaevskii equation, we obtain the Bogoliubov de-Gennes (BdG) equation for TBECs using the Hartree-Fock-Bogoliubov (HFB) theory. Based on this theory, we present the influence of radial anisotropy on TBECs in the immiscible or the phase-separated domain. In particular, the TBECs of $^{85}$Rb~-$^{87}$Rb and $^{133}$Cs~-$^{87}$Rb TBECs are chosen as specific examples of the two possible interface geometries, shell-structured and side by side, in the immiscible domain. We also show that the dispersion relation for the TBEC shell-structured interface has two branches, and anisotropy modifies the energy scale and structure of the two branches.Comment: 9 pages, 13 figure

Bifurcations, stability, and mode evolution in segregated condensate mixtures

We present new features of low energy Bogoliubov quasiparticle excitations of a two component Bose-Einstein condensate (TBEC) in quasi-2D geometry at zero temperature using Hartree-Fock-Bogoliubov (HFB). We, in particular, consider the TBECs of $^{133}$Cs~-$^{87}$Rb and $^{85}$Rb~-$^{87}$Rb, and show specific features in the low energy excitation spectrum as a function of the interaction strength. For $^{85}$Rb~-$^{87}$Rb TBEC, the appearance of a new zero energy mode is observed. Whereas for $^{133}$Cs~-$^{87}$Rb TBEC we report a bifurcation of the softened Kohn mode at the point of transition from miscible to immiscible domain. The lower energy mode, after the bifurcation, goes soft and becomes a new Goldstone mode of the system.Comment: The paper has 9 pages and 12 figure

Removal of volatile organic compounds from contaminated groundwater by pervaporation

Effective removal of non-aqueous phase liquid pools in groundwater and volatile organic compounds (VOCs) from contaminated soils can be achieved by surfactant flushing. This surfactant-rich ground water contains VOCs like trichloroethylene (TCE), dichloroethylene (DCE), etc. Membrane pervaporation technique is employed here to remove TCE from these micellar systems where a very high percentage of the VOC is trapped inside the micellar core. The micellar solution flows through the bore of microporous hydrophobic hollow fibers wherein the micelles break down and release the surfactants and the TCE. The TCE is then removed through the pores and a nonporous thin silicone skin on the outside surface of the fiber, the other side of which is subjected to vacuum to allow pervaporation-based removal of the VOC. This research has characterized such a process for removal of TCE with or without surfactant. It was established that the presence of surfactant adversely affected the removal of TCE. The flux of TCE was found to be an increasing function of feed flow rate and Reynolds number. This research has also briefly explored the permeation of nonvolatile hydrocarbons such as dodecane from water flowing through the fiber bore by using a similar hollow fiber membrane

Want to operate an abdominal lump? Think twice; it might be spontaneous rectus sheath hematoma: a case report

Rectus sheath hematoma is a rare, but potentially misdiagnosed clinical entity. It occurs when there is direct tear in the rectus abdominis muscle fibres or in the supplying blood vessels. It may be associated with trauma, raised intra-abdominal pressure, or muscle weakness. When non-traumatic, the condition is termed as spontaneous rectus sheath hematoma. Because of its rarity, spontaneous rectus hematoma can be easily missed, endangering patient management. With progressively increasing use of anticoagulant and antiplatelet agents, the incidence of this pathology is rising. We are reporting a case of spontaneous rectus sheath hematoma in a 56 year old female, known diabetic, hypertensive with dyslipidaemia on combination drug therapy but not on anticoagulant/antiplatelet medications, that was clinically misdiagnosed as omental hernia. The main presenting complaint was swelling in abdomen for 1 month. There was no history of trauma. Radiologic findings showed hypoechoic multiloculated complex cystic lesion. Cytological findings showed features of old hematoma. This case report intends to increase awareness in considering rectus sheath hematoma as an important differential diagnosis of lump abdomen. Rectus sheath hematoma, a rarely seen pathology, often confuses clinicians leading to unnecessary negative laparotomies. Definitive operative procedure should not be undertaken depending on sonographic findings alone, as the images are prone to subjective error. The main treatment modality of rectus sheath hematoma is conservative management