The characteristic features of the collapse of the ground state in trapped one-component attractive Bose-Einstein condensates are studied by applying the catastrophe theory. From numerically obtained stable and unstable solutions of the Gross-Pitaevskii equation, we derive the catastrophe function defining the stability of the stationary points on the Gross-Pitaevskii energy functional. The bif...

background: measurement of gross , gross activities, and cosmogenic beryllium-7 (7be) concentrations were made both daily and weekly during the years 2001- 2004 from samples of atmospheric aerosols filtered from the air at tehran nuclear research center (35 41' n) and zahedan (28 29' n). materials and methods: weekly aerosol samples were collected with the high-volume air samplers on ...

In two dimensions the Gross-Pitaevskii equation for a cold, dilute gas of bosons has an energy dependent coupling parameter describing particle interactions. We present numerical solutions of this equation for bosons in harmonic traps and show that the results can be quite sensitive to the precise form of the coupling parameter that is used. Solutions of the Gross-Pitaevskii equation in two dim...

The mass transport in the shallow, wind-driven, overturning cells in the tropical oceans is constrained to be close to the mass transport in the atmospheric Hadley cell, assuming that zonally integrated wind stresses on land are relatively small. Therefore, the ratio of the poleward energy transport in low latitudes in the two media is determined by the ratio of the atmospheric gross static sta...

The growing need to quantitate alpha emitting radionuclides in the environment and in nuclear fuel processing and disposal has resulted in dramatic increases in gross alpha/gross beta measurements. In fact, gross alpha/gross beta counting has become the most widely used method of monitoring for the presence of radioactivity. Much of the interest is due to the need to address safety, regulatory ...

Efficiency, the ratio of work generated to the total metabolic energy cost, has been suggested to be a key determinant of endurance cycling performance. The purpose of this brief review is to evaluate the influence of gross efficiency on cycling power output and to consider whether or not gross efficiency can be modified. In a re-analysis of data from five separate studies, variation in gross e...