Miracle-dz/UniFAR-FTUs huggingface dataset:
Actions of finite groups on finite von Neumann algebras and the relative entropy

Soit M une algebre de Von Neumann finie de trace normalisee normale τ et N une sous-algebre de Von Neumann de M. L'entropie relative H(M/N) est naturellement definie comme une notion etendue de l'entropie conditionnelle dans des cas commutatifs. On donne la formule complete sur H(M/M G ) pour une action arbitraire α d'un groupe fini G sur une algebre de Von Neumann finie M, ou M G est la sous-algebre point fixe de M sous l'action α
Study on the flow structure around a flat plate in a stagnation flow field

Numerical solutions have been obtained for steady viscous flow past a finite flat plate attached normally to an infinite wall at Reynolds numbers Re up to 2800. Separately, Levi-Civita's method has been used to obtain the flow solution based on the free-streamline theory. Apart from the case of uniform flow past an isolated obstacle, the present flow problem appeared to exhibit the validity of the free-streamline model for the global structure of the flow field. The position of the separation point could be predicted by two terms of the asymptotic solution based on the Sychev–Smith model within 0.6% error for the range 100 [les ] Re [les ] 2800.
The non-Newtonian rheology of dilute colloidal suspensions

The non-Newtonian rheology is calculated numerically to second order in the volume fraction in steady simple shear flows for Brownian hard spheres in the presence of hydrodynamic and excluded volume interactions. Previous analytical and numerical results for the low-shear structure and rheology are confirmed, demonstrating that the viscosity shear thins proportional to Pe2, where Pe is the dimensionless shear rate or Péclet number, owing to the decreasing contribution of Brownian forces to the viscosity. In the large Pe limit, remnants of Brownian diffusion balance convection in a boundary-layer in the compressive region of the flow. In consequence, the viscosity shear thickens when this boundary-layer coincides with the near-contact lubrication regime of the hydrodynamic interaction. Wakes are formed at large Pe in the extensional zone downstream from the reference particle, leading to broken symmetry in the pair correlation function. As a result of this asymmetry and that in the boundary-layer, finite normal stress differences are obtained as well as positive departures in the generalized osmotic pressure from its equilibrium value. The first normal stress difference changes from positive to negative values as Pe is increased when the hard-sphere limit is approached. This unusual effect is caused by the hydrodynamic lubrication forces that maintain particles in close proximity well into the extensional quadrant of the flow. The study demonstrates that many of the non-Newtonian effects observed in concentrated suspensions by experiments and by Stokesian dynamics simulations are present also in dilute suspensions.
Kinetic physics of the mirror instability

Kinetic mechanisms for the growth and saturation of the mirror instability are described using one-dimensional hybrid simulations. Two parameter regimes are considered. In the first regime, a relatively small ion anisotropy excites a slowly growing instability that produces small-amplitude waves; most ions respond to the waves as an adiabatic fluid. In the second regime a large anisotropy excites a rapidly growing instability that generates large-amplitude waves; the response of many ions in this case is nonadiabatic. The difference in ion response is due to the relative importance of two ion populations, resonant and nonresonant. Resonant ions, those ions with low velocities parallel to the background magnetic field, contribute to the growth of the instability as a result of their gyrointeractions with the noncoplanar component of the wave electric field and respond to the mirror waves nonadiabatically. Nonresonant ions, those with large parallel velocities, respond as an adiabatic fluid. In both regimes, ion anisotropy is reduced by means of the magnetic mirror force; in the second regime, the anisotropy is further reduced as a consequence of the field rotation at magnetic minima. The anisotropy reduction reduces the free energy available for wave growth and leads to the saturation of the mirror instability.
Clustering of luminous red galaxies – III. Baryon acoustic peak in the three-point correlation

We present the three-point function ξ 3 and Q 3 = ξ 3 /ξ 2 2 for a spectroscopic sample of luminous red galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 6 and Data Release 7. We find a strong (signal-to-noise ratio > 6) detection of Q 3 on scales of 55-125 Mpc/h, with a well-defined peak around 105 Mpc/h in all ξ 2 ,ξ 3 and Q 3 , in excellent agreement with the predicted shape and location of the imprint of the baryon acoustic oscillations (BAO). We use very large simulations (from a cubic box of L = 7680 Mpc/h) to assess and test the significance of our measurement. Models without the BAO peak are ruled out by the Q 3 data with 99 per cent confidence. This detection demonstrates the non-linear growth of structure by gravitational instability between z = 1000 and the present. Our measurements show the expected shape for Q 3 as a function of the triangular configuration. This provides a first direct measurement of the non-linear mode-coupling coefficients of density and velocity fluctuations, which, on these large scales, are independent of cosmic time, the amplitude of fluctuations or cosmological parameters. The location of the BAO peak in the data indicates Ω m = 0.28 ± 0.05 and Ω B = 0.079 ± 0.025 (for h = 0.70) after marginalization over spectral index (n s = 0.8-1.2) linear b 1 and quadratic c 2 bias, which are found to be in the range: b 1 = 1.7-2.2 and c 2 = 0.75-3.55. The data allow a hierarchical contribution from primordial non-Gaussianities in the range Q 3 = 0.55-3.35. These constraints are independent and complementary to the ones that can be obtained using the two-point function, which are presented in a separate paper. This is the first detection of the shape of Q 3 on BAO scales, but our errors are shot noise dominated and the SDSS volume is still relatively small, so there is ample room for future improvement in this type of measurements.
Dramatic thermal conductivity reduction by nanostructures for large increase in thermoelectric figure-of-merit of FeSb2

In this report, thermal conductivity reduction by more than three orders of magnitude over its single crystal counterpart for the strongly correlated system FeSb2 through a nanostructure approach was presented, leading to a significant increase of thermoelectric figure-of-merit (ZT). For the samples processed with the optimal parameters, the thermal conductivity reached 0.34 Wm−1 K−1 at 50 K, leading to a ZT peak of about 0.013, compared to 0.005 for single crystal FeSb2, an increase of about 160%. This work suggests that nanostructure method is effective and can be possibly extended to other strongly correlated low temperature thermoelectric materials, paving the way for future cryogenic temperature cooling applications.
On the Axiomatic Ranking of Opportunity Sets in a Logical framework

The paper presents an axiomatic analysis of opportunity ranking within a logical framework. It establishes that any opportunity or freedom ranking is completely determined by a subjacent logical chain that is interpreted as a freedom standard. However, a preferential interpretation of the chain is also possible and it leads to the results similar to those already obtained by Nehring and Puppe (1999).
Oblique section of a paraxial light beam: criteria for azimuthal energy flow and orbital angular momentum

Comparison of the intensity distributions in a transverse cross section, orthogonal to the beam propagation axis, and in an oblique section, inclined to the axis by some acute angle, provides information about the transverse energy flows in the beam, in particular, the transverse energy circulation. The beam intensity pattern in an oblique section differs from the ‘geometric-optics’ expectations, which can be quantitatively described by the corresponding shift of the beam ‘centre of gravity’. Measurements of this shift can be used for the study and characterization of the transverse energy flows and for evaluation of the beam orbital angular momentum. Situations in which the intensity distribution in oblique sections plays an important role occur in the beam transformation at a diffraction grating (in non-zero diffraction orders) and even at the beam propagation through a reflecting boundary. An optical vortex generation with the help of a hologram possessing a ‘fork’ structure supplies a special case of such a situation.
A Revised Conceptual Model of the Tropical Marine Boundary Layer. Part II: Detecting Relative Humidity Layers Using Bragg Scattering from S-Band Radar

AbstractPersistent layers of enhanced equivalent radar reflectivity factor and reduced spectral width were commonly observed within cloud-free regions of the tropical marine boundary layer (TMBL) with the National Center for Atmospheric Research S-Pol radar during the Rain in Cumulus over the Ocean (RICO) field campaign. Bragg scattering is shown to be the primary source of these layers. Two mechanisms are proposed to explain the Bragg scattering layers (BSLs), the first involving turbulent mixing and the second involving detrainment and evaporation of cloudy air. These mechanisms imply that BSLs should exist in layers with tops (bases) defined by local relative humidity (RH) minima (maxima). The relationship between BSLs and RH is explored.An equation for the vertical gradient of radio refractivity N is derived, and a scale analysis is used to demonstrate the close relationship between vertical RH and N gradients. This is tested using the derived radar BSL boundary altitudes, 131 surface-based soundings,.
Airfoil Aerodynamics in Ground Effect for Wide Range of Angles of Attack

The aerodynamics and flow physics of a NACA 4412 airfoil in ground effect for a wide range of angles of attack from −4 to 20 deg are investigated by numerical simulations. The compressible Reynolds-averaged Navier–Stokes equations and shear-stress transport k-ω turbulence model equations are solved using the finite-volume method. Analyses of the computed results show that the angle of attack versus height (above the ground) plane can be divided into three regions based on the sign of the lift increment value: region I of positive ground effect, and regions II and III of negative ground effect. For low-to-moderate angles of attack, when the ride height is reduced, the airflow is blocked in the convergent passage between the lower surface of the airfoil and the ground, resulting in increase of pressure on the lower surface of the airfoil. As a consequence, the effective angle of attack decreases, and there is less upward deflection of the streamlines, resulting in an increase in pressure on the upper surfac.
The annual cycle of persistence in the El Nño/Southern Oscillation

A spring ‘predictability barrier’ exists in both data and models of the El Niño/Southern Oscillation (ENSO) phenomenon. In statistical analyses this barrier manifests itself as a drop‐off in monthly persistence (lagged correlation) while in coupled ocean‐atmosphere models it appears as a decrease in forecast skill.
Dynamic response of a rotating timoshenko shaft subject to axial forces and moving loads

Abstract The dynamic response of a rotating shaft subject to axial force and moving loads is analyzed by using Timoshenko beam theory and the assumed mode method. The deformations of the shaft are expressed in terms of an inertial reference frame. The kinetic and potential energy are then expressed in matrix form by using the assumed mode method. The resulting equations of motion in matrix form are derived by using Hamilton’s principle. The influences of the rotational speed of the shaft, the axial speed of the loads, and the Rayleigh coefficient are investigated and compared with the available reported results. The effects of compressive axial forces and perturbation of the axial velocity of the moving loads are also included in the analysis.
The structure of the turbulent boundary layer on a cylinder in axial flow

The thick, turbulent boundary layer, which develops as a fluid flows parallel to a cylinder, has been experimentally characterized for the case where the boundary layer is thick compared to the radius of transverse curvature. Measurements of the turbulence intensity, velocity spectra, and intermittency are qualitatively similar to those for the planar boundary layer. Although measurements of wall shear stress using several different techniques have substantial scatter, the wall shear stress appears to be larger than that for the turbulent boundary layer on a flat plate at the same Reynolds number based on streamwise distance. The variable interval time averaging (VITA) and uv‐quadrant techniques were used to detect the burst cycle near the wall. Conditionally averaged velocities were similar to those for a flat plate boundary layer indicating a similar burst cycle near the wall. However, the VITA frequency scaling indicates an interaction between the flow in the wall region and the outer flow. Flow visual.
Time-Adaptive, Loosely Coupled Strategy for Conjugate Heat Transfer Problems in Hypersonic Flows

This paper describes the development of a novel, time-adaptive, loosely coupled analysis strategy for efficiently predicting the conjugate heat transfer problems in hypersonic flows. Considering many orders of magnitude disparity of physical characteristic time scales between hypersonic flow behavior and structural heat transfer, a loosely coupled strategy is first developed to efficiently couple an aerodynamic flow computational fluid dynamics solver with a structural heat transfer finite element method solver. Then, an adaptive coupling time stepsize approach based on a control theory point of view is proposed and embedded into this strategy for further efficiency. Finally, the performance of the proposed time-adaptive, loosely coupled analysis strategy is evaluated by performing conjugate heat transfer simulations over a cylindrical leading-edge model. The computational results are presented and analyzed, indicating that this strategy can offer the potential for significant improvements in predicting t.
Efficient image reconstruction from sign and energy information

In recent year several algorithms for signal reconstruction from sign information have been developed. In this paper we propose an improved version of the 1D algorithm presented, with the following new characteristics: (1) restriction of the input data space to the set of energy normalized bandpass functions, (2) preservation of the global energy content of the original signal, and (3) implicit determination of the scaling constant. Simulation results show that the restriction of the solution data space to the set on energy normalized functions leads, in general, to a reconstruction that, even if is not coincident in all the zerocrossing positions to the original signal, seems to be stable in L2 sense. A complete coding scheme based on the JBIG standard for an efficient encoding of the zerocrossing is presented. Encouraging results have been obtained both at reconstruction and at coding level that show the feasibility of the global scheme.
Large-eddy simulation of a buoyant plume in uniform and stably stratified environments

We consider large-eddy simulation (LES) of buoyant plumes in uniform and stably stratified environments. We show that in the former case the results agree well with the simple plume model of Morton, Taylor & Turner (Proc. R. Soc. Lond. A, vol. 234, 1956, p. 1). In particular, we calculate an entrainment constant which is consistent with laboratory and field measurements and find no significant difference between the radial spreading rates of vertical velocity and buoyancy. In a stably stratified environment, the LES plume shows better agreement with Morton et al. (1956) below the level at which the buoyancy first vanishes than above this level. Above the level of neutral buoyancy, the LES plume is characterized by an ascending core of negative buoyancy surrounded by a descending annulus of positive buoyancy. We compare the LES data with the model of Bloomfield & Kerr (J. Fluid Mech., vol. 424, 2000, p. 197), which explicitly accounts for these coherent motions. The model exhibits many qualitative aspects of the LES plume and quantitative agreement can be improved by adjusting the downward volume flux relative to the upward volume flux in a manner consistent with the LES plume. This simple adjustment, along with revised values of the entrainment constants, represents the combined effects of an overturning region at the top of the plume (where a fluid element reverses direction), ‘plume-top’ entrainment (whereby the plume entrains ambient fluid above the plume) as well as lateral entrainment and detrainment processes (both external and internal) occurring above the top of the model plume.
Threshold shift of helical dynamo induced by stochastic flow fluctuations

We study the generation of magnetic field by a helical flow made of a mean steady flow plus a fluctuating flow assumed to behave like a Gaussian white noise. The steady flow and the fluctuations are both solid body screw motions with constant pitches, respectively, and . The threshold shift induced by fluctuations of small amplitude is calculated analytically as a function of for different values of , m and k being the axial and azimuthal wavenumbers of the magnetic field. For a fixed value of , negative threshold shifts have been found provided belongs to a bounded interval . When there is no mean flow, the analysis is extended to temporal fluctuations modeled by a colored noise. In that case, emphasis is put on the influence of the correlation time on the dynamo onset.
Sex-dependent Clinical Presentation, Body Image, and Endocrine Status in Long-term Remitted Anorexia Nervosa

Objective Although anorexia nervosa (AN) in males has recently gained attention, knowledge of its psychological and physiological outcomes is still scarce. We explore sex-specific characteristics of long-term remitted AN with respect to residual eating disorder psychopathology, body image, and endocrinology. Method We recruited 33 patients with AN in remission for at least 18 months (24 women, 9 men) and 36 matched healthy controls (HCs). Eating disorder psychopathology and body image ideals were assessed via clinical interviews, questionnaires, and an interactive 3D body morphing tool. Plasma levels of leptin, free triiodothyronine, cortisol, and sex hormones were quantified. Univariate models controlled for age and weight were used to test for the effects of diagnosis and sex. Results Both patient groups showed residual eating disorder psychopathology but normal weight and hormone levels relative to HCs. Male remitted patients demonstrated significantly stronger muscularity-focused body image ideals, evident in interviews, self-reports, and behavioural data, than both female patients and HCs. Conclusions Sex-specific body image characteristics in patients with remitted AN point towards the need to adjust test instruments and diagnostic criteria to male-specific psychopathology. In the future, sufficiently powered studies should evaluate the risk of men with AN developing muscle dysmorphia in the long term.
Divergence of wastewater SARS-CoV-2 and reported laboratory-confirmed COVID-19 incident case data coincident with wide-spread availability of at-home COVID-19 antigen tests

Concentrations of SARS-CoV-2 RNA in wastewater settled solids from publicly owned treatment works (POTWs) historically correlated strongly with laboratory confirmed incident COVID-19 case data. With the increased availability of at-home antigen tests since late 2021 and early 2022, laboratory test availability and test seeking behavior has decreased. In the United States, the results from at-home antigen tests are not typically reportable to public health agencies and thus are not counted in case reports. As a result, the number of reported laboratory-confirmed incident COVID-19 cases has decreased dramatically, even during times of increased test positivity rates and wastewater concentrations of SARS-CoV-2 RNA. Herein, we tested whether the correlative relationship between wastewater concentrations of SARS-CoV-2 RNA and reported laboratory-confirmed COVID-19 incidence rate has changed since 1 May 2022, a point in time immediately before the onset of the BA.2/BA.5 surge, the first surge to begin after at-home antigen test availability was high in the region. We used daily data from three POTWs in the Greater San Francisco Bay Area of California, USA for the analysis. We found that although there is a significant positive association between wastewater measurements and incident rate data collected after 1 May 2022, the parameters describing the relationship are different than those describing the relationship between the data collected prior to 1 May 2022. If laboratory test seeking or availability continues to change, the relationship between wastewater and reported case data will continue to change. Results suggests that, assuming SARS-CoV-2 RNA shedding remains relatively stable among those infected with the virus as different variants emerge, that wastewater concentrations of SARS-CoV-2 RNA can be used to estimate COVID-19 cases as they would have been during the time when laboratory testing availability and test seeking behavior were at a high (here, before 1 May 2022) using the historical relationship between SARS-CoV-2 RNA and COVID-19 case data.
Circulating Extracellular Vesicles in Human Cardiorenal Syndrome Promote Renal Injury

Background: Cardiorenal syndrome (CRS) renal injury during heart failure (HF) is linked to higher morbidity. Whether circulating extracellular vesicles (EVs) and their RNA cargo directly impact its pathogenesis remains unclear. Methods: Using a microfluidic kidney chip model (KC), we investigated transcriptional effects of circulating EVs from patients with CRS on renal epithelial/endothelial cells. We used small RNA-seq on circulating EVs and regression to prioritize subsets of EV miRNAs associated with serum creatinine, a biomarker of renal function. In silico pathway analysis, human genetics, and interrogation of expression of miRNA target genes in the KC model and in a separate cohort of individuals post-renal transplant with microarray-based gene expression was performed for validation. Results: Renal epithelial and endothelial cells in the KC model exhibited uptake of EVs. EVs from patients with CRS led to higher expression of renal injury markers (IL18, NGAL, KIM1) a greater cystatin C secretion relative to non-CRS EVs. Small RNA-seq and regression identified 15 miRNAs related to creatinine, targeting 1143 gene targets specifying pathways relevant to renal injury, including TGF-beta and AMPK signaling. We observed directionally consistent changes in expression of TGF-b pathway members (BMP6, FST, TIMP3) in KC model exposed to CRS EVs, as well as in renal tissue after transplant rejection. Mendelian randomization suggested a role for FST in renal function. Conclusion: EVs from patients with CRS directly elicit adverse transcriptional and phenotypic responses in a KC model by regulating biologically relevant pathways, suggesting a novel role for EVs in CRS.