Meridional circulation of gas into gaps opened by giant planets in three-dimensional low-viscosity disks

We examine the gas circulation near a gap opened by a giant planet in a protoplanetary disk. We show with high resolution 3D simulations that the gas flows into the gap at high altitude over the mid-plane, at a rate dependent on viscosity. We explain this observation with a simple conceptual model. From this model we derive an estimate of the amount of gas flowing into a gap opened by a planet with Hill radius comparable to the scale-height of a layered disk (i. e. a disk with viscous upper layer and inviscid midplane). Our estimate agrees with modern MRI simulations(Gressel et al., 2013). We conclude that gap opening in a layered disk can not slow down significantly the runaway gas accretion of Saturn to Jupiter-mass planets.Comment: in press as a Note in Icaru

Possibility of \Lambda\Lambda pairing and its dependence on background density in relativistic Hartree-Bogoliubov model

We calculate a \Lambda\Lambda pairing gap in binary mixed matter of nucleons and \Lambda hyperons within the relativistic Hartree-Bogoliubov model. Lambda hyperons to be paired up are immersed in background nucleons in a normal state. The gap is calculated with a one-boson-exchange interaction obtained from a relativistic Lagrangian. It is found that at background density \rho_{N}=2.5\rho_{0} the \Lambda\Lambda pairing gap is very small, and that denser background makes it rapidly suppressed. This result suggests a mechanism, specific to mixed matter dealt with relativistic models, of its dependence on the nucleon density. An effect of weaker \Lambda\Lambda attraction on the gap is also examined in connection with revised information of the \Lambda\Lambda interaction.Comment: 8 pages, 6 figures, REVTeX 4; substantially rewritten, emphasis is put on the LL pairing in pure neutron matte

Numerical simulation on drying process of an inkjet droplet using lagrangian FEM

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.A mathematical model is proposed to describe the fluid dynamics, mass and heat transfer in a solution droplet evaporating on a flat surface during drying process. A decrease of droplet volume due to evaporation of a solvent, evaporation latent heat generated on the free surface, and an increase of a solute on the free surface are considered in the model. Governing equations are numerical solved using a finite element method. A Lagrangian method is applied to predict the deformation of an evaporating droplet. Firstly, the outward flow caused during selfpinning of the contact line are examined under an ideal condition. The calculated velocities agree well with calculated results using a one-dimensional model. Secondly, the drying process of a polystyrene/anisole solution droplet with the equivalent diameter of 20 µm are estimated. The migration of the solute at the contact line is found to be finished by the instant when a thin liquid film with a low solute concentration are still remained at the center part. As a result, a ring structure develops on the periphery of the dried film. Lastly, the effect of fluid viscosity is investigated. A high viscosity essentially decreases the fluid velocity, resulting in vanishing the ring structure. The effect of viscosity on the configuration of the film agrees with empirical results.cf201

On the Origin of HD149026b

The high density of the close-in extrasolar planet HD149026b suggests the presence of a huge core in the planet, which challenges planet formation theory. We first derive constraints on the amount of heavy elements and hydrogen/helium present in the planet: We find that preferred values of the core mass are between 50 and 80 M_E. We then investigate the possibility of subcritical core accretion as envisioned for Uranus and Neptune and find that the subcritical accretion scenario is unlikely in the case of HD149026b for at least two reasons: (i) Subcritical planets are such that the ratio of their core mass to their total mass is above ~0.7, in contradiction with constraints for all but the most extreme interior models of HD149026b; (ii) High accretion rates and large isolation mass required for the formation of a subcritical core of 30 M_E are possible only at specific orbital distances in a disk with a surface density of dust equal to at least 10 times that of the minimum mass solar nebula. This value climbs to 30 when considering a 50 M_E core. These facts point toward two main routes for the formation of this planet: (i) Gas accretion that is limited by a slow viscous inflow of gas in an evaporating disk; (ii) A significant modification of the composition of the planet after as accretion has stopped. These two routes are not mutually exclusive. Illustrating the second route, we show that for a wide range of impact parameters, giant impacts lead to a loss of the gas component of the planet and thus may lead to planets that are highly enriched in heavy elements. In the giant impact scenario, we expect an outer giant planet to be present. Observational studies by imaging, astrometry and long term interferometry of this system are needed to better narrow down the ensemble of possibilities.Comment: 29 pages, 8 figures, to appear in the 10 October 2006 issue of Ap

Diurnal pattern of salivary cortisol and progression of aortic stiffness: Longitudinal study

Background: The positive direct relation between stress and the development of cardiovascular disease has increasingly been recognized. However, the link between hypothalamic-pituitary-adrenal (HPA) dysregulation and subclinical cardiovascular disease has not been studied longitudinally. We investigated the relation of diurnal salivary cortisol, as a biological marker of stress levels, with progression of aortic stiffness over five years. Methods: A total of 3281 people (mean age 65.5) in the Whitehall II prospective study provided six saliva samples on a single weekday. We assessed the diurnal salivary cortisol using the daytime slope and bedtime level. Aortic stiffness was measured by carotid-femoral pulse wave velocity (PWV) at baseline (2007–2009) and five years later (2012–2013). Linear mixed models were used to estimate the association of diurnal salivary cortisol with baseline PWV and five-year longitudinal changes. Results: Diurnal salivary cortisol were not associated with PWV at baseline. Among women but not men, a 1-SD shallower salivary cortisol slope at baseline was associated with a five-year increase in PWV (β = 0.199; 95% CI = 0.040, 0.358 m/s) and higher bedtime cortisol level (β = 0.208, 95% CI = 0.062, 0.354 m/s). Conclusions: Dysregulation of the HPA axis measured using salivary cortisol (shallower slope, higher bedtime level) predicted the rate of progression of aortic stiffness among women

Spatial structure of quark Cooper pairs in a color superconductor

Spatial structure of Cooper pairs with quantum numbers color 3^*, I=J=L=S=0 in ud 2 flavor quark matter is studied by solving the gap equation and calculating the coherence length in full momentum range without the weak coupling approximation. Although the gap at the Fermi surface and the coherence length depend on density weakly, the shape of the r-space pair wave function varies strongly with density. This result indicates that quark Cooper pairs become more bosonic at higher densities.Comment: 10 pages, 3 figures. The frequency dependence of the gap and the limitation on the type I/type II discussion are mentioned briefly. To appear in Phys. Rev.

Unusual reticulin staining pattern in well-differentiated hepatocellular carcinoma

<p>Abstract</p> <p>Background</p> <p>Special stains, such as reticulin stain and CD34 immunostain, are very helpful in the diagnosis of well differentiated hepatocellular carcinoma (HCC). Most studies have shown that absent or decreased reticulin stain or an abnormal reticulin pattern with widened trabeculae is reliable for the diagnosis of well-differentiated HCC.</p> <p>Case report</p> <p>We report here two cases of well differentiated HCC with an unusual reticulin staining pattern. A strongly positive reticulin network was preserved within the tumor, which surrounded individual tumor cells in a monolayered trabecular pattern. At the same time, an increased CD34 stain was present in the tumor.</p> <p>Conclusions</p> <p>This unusual reticulin pattern represents part of the diverse reticulin staining patterns seen in HCC. Although this staining pattern is rare, it should be recognized when diagnosing well-differentiated HCC in small samples such as cellblock of fine needle aspiration or small core biopsies.</p