gas mixing in a t-shape micro mixer has been simulated using the direct simulation monte carlo (dsmc) method. it is considered that the adequate mixing occurs when the mass composition of the species, co or n2, deviates below 1 % from their equilibrium composition. the mixing coefficient is defined as the ratio of the mixing length to the main channel’s height. as the inlet kn increases, while ...

In order to detect the early fatigue crack of mechanical components simply, this paper puts forward ultrasonic testing technology different side collinear mixing. Firstly, based on nonlinear theory, method calculating difference frequency and sum coefficients mixing is deduced. Then, ram-5000 SINAP system used aluminum alloy specimens with five depth cracks, corresponding spectrum diagram drawn...

background: dams are one of the most important manmade buildings to provide of drinking water. in order to manage of water quality in dams reservoirs, the recognition of phenomena that occurred in it is essential. thermal stratification is one of the major problems that decrease the water quality of dam. the aim of this study was to investigate thermal stratification of ekbatan dam (hamadan) as...

The influence of dose rate, i.e., ion flux, on ion beam mixing in Nb-Si bilayer samples was measured at room temperature and 325 °C. At the higher temperature, an increase in dose rate of a factor of 20 caused a decrease in the thickness of the mixed layer by a factor of 1.6 for equal total doses. At room temperature, the same change in flux had no effect on mixing. These results are consistent...

Because of photoacclimation, frequency distributions of phytoplankton single-cell fluorescence reflect variation in light histories among individual cells. As a result, phytoplankton can be used as biological tracers for vertical mixing. A time series of Prochlorococcus single-cell fluorescence distributions in the Sargasso Sea revealed changes that were qualitatively consistent with changes in...

Evolution of Stars of masses 60Me, 20Me and 12Me is computed mainly for a limiting case where neutrino loss due to the universal Fermi interaction is completely neglected. Convective envelope penetrates deeply into the highly evolved core, but the depth of penetration is found to depend on the stellar mass and the efficiency of convective energy transport_ When the mixing proceeds quickly, the ...

[1] An abrupt mixing event in the upper ocean is investigated in the Northwestern Mediterranean Sea using gliders, a new ocean monitoring technology, combined with regional atmospheric model outputs and mooring data. Intense winds (up to 20 m s ) and buoyancy forcing during December 2009 induced strong vertical mixing of the upper ocean layer in the Balearic Sea. High-resolution data from a coa...

[1] Satellite measurements allow global assessments of phytoplankton concentrations and, from observed temporal changes in biomass, direct access to net biomass accumulation rates (r). For the subarctic Atlantic basin, analysis of annual cycles in r reveals that initiation of the annual blooming phase does not occur in spring after stratification surpasses a critical threshold but rather occurs...

We have devised a method, based on a parametric array concept, to create a low-frequency (300-500 kHz) collimated ultrasound beam in fluids highly attenuating to sound. This collimated beam serves as the basis for designing an ultrasound visualization system that can be used in the oil exploration industry for down-hole imaging in drilling fluids. We present the results of two different approac...

The depth of the planetary boundary layer (PBL) is a climatologically important quantity that has received little attention on regional to global scales. Here a 10-yr climatology of PBL depth from the University of California, Los Angeles (UCLA) atmospheric GCM is analyzed using the PBL mass budget. Based on the dominant physical processes, several PBL regimes are identified. These regimes tend...