light is never being distributed homogeneously and it forms a gradient over biomass. the unidirectional nature of light gives rise to a vertical gradient of light intensity as a function of depth. the maximum depth of the light zone suitable for phytoplankton photosynthesis is designated as the euphotic depth. this study was designed to test the hypothesis of mixing depth of phytoplankton and i...

light is never being distributed homogeneously and it forms a gradient over biomass. the unidirectional nature of light gives rise to a vertical gradient of light intensity as a function of depth. the maximum depth of the light zone suitable for phytoplankton photosynthesis is designated as the euphotic depth. this study was designed to test the hypothesis of mixing depth of phytoplankton and i...

It is well known that one can use B → ππ decays to probe the CP-violating phase α. In this paper we show that these same decays can be used to search for new physics. This is done by comparing two weak phases which are equal in the standard model: the phase of the t-quark contribution to the b → d penguin amplitude, and the phase of B d–B 0 d mixing. In order to make such a comparison, we requi...

the main objective of a research program, whose output is presented here, has been to estimate “ventilation coefficients”, a critical parameter in determining air pollution concentration near the surface ground which signifies the ability for natural ventilation of an air shed in an urban or rural area. relevant measured data from the city of tehran has been used to calibrate and further de...

According to a recent dynamical model, the depth of a well-mixed water column should have contrasting effects on the abundances of sinking and nonsinking phytoplankton taxa. Because of increasing light limitation, nonsinking taxa should decline monotonically with increasing mixing depth, and because of sinking loss limitation at low mixing depths, sinking taxa should peak at intermediate mixing...

Most phytoplankton production occurs in the turbulently mixed surface layer of lakes and oceans. Environmental factors such as mixed layer depth and background turbidity substantially influence the availability of essential, production-limiting resources, i.e., light and nutrients. We tested the predictions of a dynamic model concerning the effects of water column mixing depth and background tu...

The chaotic mixing in a drop moving through a winding channel is studied computationally in a two-dimensional setting. The molecular mixing is ignored and only the mixing due to the chaotic advection is considered. Passive tracer particles are used to visualize the mixing patterns and mixing is quantified by two distinct methods. It is found that both the quantification methods are consistent w...

[1] Vertical mixing plays a major role in functioning of seasonally stratified aquatic systems. In this study, we employ a 1-D stratification model and a 9 year forcing data set to simulate the thermal dynamics in a large, but shallow reservoir that regularly displays a polymictic character with complete mixing events during summer. Such mixing dynamics is typical for many water bodies in the t...

Atomic mixing and preferential sputtering impose a depth resolution limit on the use of sputter sectioning to measure the composition of metal-semiconductor interfaces. Experimental evidence obtained with the Pt-Si system is used to .demonstrate ion-induced atomic mixing and then its effect on sputter etching and depth profiling. Starting with discrete layer structures, a relatively low ion dos...

[1] Glacial boulders and soils on moraines are often dated to quantify the timing of glaciations and/or rates of chemical weathering in moraine chronosequences. A common assumption is that moraine crest erosion and soil mixing are unimportant. However, several studies suggest moraine denudation may be substantial. We evaluate the magnitude of moraine denudation and soil mixing in the Pinedale (...