We present the results of solar model computation done with the latest Livermore opacities. Models without diffusion, with hydrogen diffusion only and with hydrogen and heavy elements diffusion are considered. The influence of mixing below the convective envelope induced by rotation and angular momentum losses is also discussed. The sound speed of our best model, does not deviate from that of B...

A mechanism for fast magnetic reconnection in collisionless plasma is studied for understanding sawtooth collapse in tokamak discharges. Nonlinear growth of the tearing mode driven by electron inertia is analytically estimated by invoking the energy principle for the first time. Decrease of potential energy in the nonlinear regime (where the island width exceeds the electron skin depth) is foun...

We report the first experimental observation of a spatially localized dynamo magnetic field, a common feature of astrophysical dynamos and convective dynamo simulations. When the two propellers of the von Kármán sodium experiment are driven at frequencies that differ by 15%, the mean magnetic field's energy measured close to the slower disk is nearly 10 times larger than the one close to the fa...

In this work, we study the interaction between a tearing mode and a pressure gradient instability (resistive interchange) by solving reduced MHD equations numerically. The numerical study shows existence of regimes where thetearing instability is driven by the pressure gradient. An interplay between the pressure and the magnetic flux controls the dynamics of the saturated state. A secondary ins...

A simple model to study interacting instabilities and textures of resulting patterns for thermal convection is presented. The model, consisting of a twelve-mode dynamical system derived for periodic square lattice, describes convective patterns in the form of stripes and patchwork quilt. The interaction between stationary zigzag stripes and standing patchwork quilt pattern leads to spatiotempor...

Temporal and spatial variations of convection in South Asia are analyzed using eight years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) data and NCEP reanalysis fields. To identify the most extreme convective features, three types of radar echo structures are defined: deep convective cores (contiguous 3D convective echo $40 dBZ extending $10 km in height) represent the...

impulsive and convective frequencies are one of the most important subjects for evaluation of the seismic behavior of tanks. these two frequencies are defined by housner and used for obtaining rayleigh damping in time history analysis. aci 350 and nzsee standards have suggested some analytical solutions for finding convective and impulsive frequencies. these frequencies can also extract from mo...

Climate and reanalysis models contain large water and energy budget errors over tropical land related to the misrepresentation of diurnally forced moist convection. Motivated by recent work suggesting that the water and energy budget is influenced by the sensitivity of the convective diurnal cycle to atmospheric state, this study investigates the relationship between convective intensity, the c...

the present experimental study reports on enhancement of heat transfer by addition of nanoparticles to the working fluid of commercial swimming pool heat exchangers under laminar flow condition. three different concentrations of titanium dioxide nanoparticles were added to the water as working fluid of a typical forced convective heat exchanger used to transfer heat to public swimming pools. th...

banana samples were purchased from a local market in sabzevar located at northeast of iran. then samples stored at refrigerator between 5–10oc during experiments, for prevention of chilling injury, 36 samples at three replications were prepared so as bananas were peeled and sliced with a sharp knife at three thicknesses (3, 5 and 10 mm) and then treated by three pretreatment methods (t1: chemic...