Investigation of Thermocapillary Convection of High Prandtl Number Fluid Under Microgravity

Thermocapillary convection in a liquid bridge, which is suspended between two coaxial disks under zero gravity, has been investigated numerically. The Navier-Stokes equations coupled with the energy conservation equation are solved on a staggered grid, and the level set approach is used to capture the free surface deformation of the liquid bridge. The velocity and temperature distributions inside the liquid bridge are analyzed. It is shown from this work that as the development of the thermocapillary convection, the center of the vortex inside the liquid bridge moves down and reaches an equilibrium position gradually. The temperature gradients in the regions near the upper center axis and the bottom cold corner are higher than those in the other regions

Synthetic Landau levels and spinor vortex matter on Haldane spherical surface with magnetic monopole

We present a flexible scheme to realize exact flat Landau levels on curved spherical geometry in a system of spinful cold atoms. This is achieved by Floquet engineering of a magnetic quadrupole field. We show that a synthetic monopole field in real space can be created. We prove that the system can be exactly mapped to the electron-monopole system on sphere, thus realizing Haldane's spherical geometry for fractional quantum Hall physics. The scheme works for either bosons or fermions. We investigate the ground state vortex pattern for an $s$-wave interacting atomic condensate by mapping this system to the classical Thompson's problem. We further study the distortion and stability of the vortex pattern when dipolar interaction is present. Our scheme is compatible with current experimental setup, and may serve as a promising route of investigating quantum Hall physics and exotic spinor vortex matter on curved space.Comment: 11 pages, 4 figure

Investigation on the Compressibility Characteristics of Low Mach Number Laminar Flow in Rotating Channel

In high-speed rotating channels, significant compressive effects are observed, resulting in distinct flow characteristics compared to incompressible flows. In this study, we employed a finite volume method based on the simple algorithm to solve for low-speed compressible laminar flow within rotating channels using an orthogonal uniform grid. The governing equations include the full Navier-Stokes equations and the energy equation. Contrary to stationary channel, the alterations in flow within rotating channel are primarily influenced by the compressive effects of centrifugal force and the compressibility of fluid within the flow's normal section. The first effect involves a reduction in the velocity due to centrifugal force, leading to an increasing influence of the Coriolis force compared to inertial forces along the flow direction. This trend in axial changes aligns closely with the increase in rotation speed. The second effect arises from the increase in Mach number and the Coriolis compression, resulting in slight density differences within the cross-section. Strong centrifugal forces generate significant centrifugal additional force (buoyancy force). Consequently, under the same local rotation number, the velocity profiles of the mainstream experience considerable changes. Additionally, higher Mach number significantly impact wall shear stress, with the leading side being notably affected. For instance, at a cross-sectional Ro = 0.6 and Ma = 0.035, the dimensionless shear stress on the leading side decreased by 13%. Furthermore, while an increase in Mach number has minimal impact on the cross-sectional secondary flow structure, changes in mainstream velocity profiles influence secondary flow intensity, resulting in an enhanced velocity peak and a shift towards the trailing side

Observation of a red-blue detuning asymmetry in matter-wave superradiance

We report the first experimental observations of strong suppression of matter-wave superradiance using blue-detuned pump light and demonstrate a pump-laser detuning asymmetry in the collective atomic recoil motion. In contrast to all previous theoretical frameworks, which predict that the process should be symmetric with respect to the sign of the pump-laser detuning, we find that for condensates the symmetry is broken. With high condensate densities and red-detuned light, the familiar distinctive multi-order, matter-wave scattering pattern is clearly visible, whereas with blue-detuned light superradiance is strongly suppressed. In the limit of a dilute atomic gas, however, symmetry is restored.Comment: Accepted by Phys. Rev. Let

Study of the Effect of a Novel Dimensionless Parameter -- the Centrifugal Work Number(CW), on Spanwise Rotating channel Low-speed Compressible Flow

In the study of similarity of rotating channel flow, we found that the flow obtained from the enlarged model under the theory of incompressible rotation similarity (maintaining geometric similarity and the same Reynolds number, rotation number, Prandtl number and buoyancy number) differs significantly from the flow inside the original channel. Through theoretical derivation and dimensional analysis, we discovered another significant parameter -- the centrifugal work number(CW), which characterizes the ratio of centrifugal work to gas enthalpy in the rotating channel and is an important parameter for measuring the compressibility of fluids inside the rotating channel. Moreover, we have verified the effect of the centrifugal work ratio on the flow state of the rotating channel using numerical methods, further improving the similarity theory of rotating channel compressible flow.Comment: 16 pages, 6 figure

Secukinumab shows significant efficacy in palmoplantar psoriasis: Results from GESTURE, a randomized controlled trial

Background: Plaque psoriasis affecting palms and soles is disabling and often resistant to treatment. Objective: Evaluate the efficacy and safety of secukinumab, an anti-interleukin 17A antibody, in subjects with palmoplantar psoriasis. Methods: In this double-blinded, randomized controlled trial, 205 subjects were randomized 1:1:1 to secukinumab 300 mg, 150 mg, or placebo. The primary endpoint was Palmoplantar Investigator's Global Assessment (ppIGA) 0 (clear) or 1 (almost clear/minimal) response at week 16. Results: At week 16, the percentage of subjects who achieved clear or almost clear palms and soles (or ppIGA 0/1) with secukinumab 300 mg (33.3%) and 150 mg (22.1%) was superior to the percentage achieved with placebo (1.5%, . P < .001). Palmoplantar Psoriasis Area and Severity Index (ppPASI) was significantly reduced with secukinumab 300 mg (-54.5%) and 150 mg (-35.3%) compared with placebo (-4.0%, . P < .001). Dermatology Life Quality Index (DLQI) 0/1 responses from subjects in the secukinumab groups were also significantly higher compared with placebo at week 16 (P < .01) and pain and function of palms and soles was markedly improved with secukinumab as measured by the palmoplantar Quality-of-Life Instrument. Secukinumab 300 mg consistently showed the best outcomes. The safety profile was favorable and similar to previous studies. Limitations: Lack of active comparator. Conclusion: In GESTURE, the largest randomized controlled trial in palmoplantar psoriasis, secukinumab demonstrated the greatest efficacy to date for treating difficult-to-treat psoriasis