Three-dimensional numerical simulations of convection and magnetic ®eld generation in the Earth’s core now span several hundred thousand years; the magnetic ®eld created during most of this time has an intensity, structure and time dependence similar to the present geomagnetic ®eld. Five models are described here. The ®rst is a homogeneous Boussinesq model, driven steadily by heat sources on th...

We describe a simple strontium vapor cell for laser spectroscopy experiments. Strontium vapor is produced using an electrically heated commercial dispenser source. The sealed cell operates at room temperature, and without a buffer gas or vacuum pump. The cell was characterized using laser spectroscopy, and was found to offer stable and robust operation, with an estimated lifetime of >10 000 h. ...

â  natural disasters are known as one the most important factors in demolition human settlement. so study of impacts of natural disasters one human settlements specially cities are an important for urban planners iran had been faced with natural disasters specific earth quake because of its geographical position (its located on world earth quake belt). some earth quakes cause many human, financ...

The distribution of rainforest in many regions across the Earth was strongly affected by Pleistocene ice ages. However, the extent to which these dynamics are still important for modern-day biodiversity patterns within tropical biodiversity hotspots has not been assessed. We employ a comprehensive dataset of Madagascan palms (Arecaceae) and climate reconstructions from the last glacial maximum ...

Abstract. The stability of the Greenland Ice Sheet under global warming is governed by a number dynamic processes and interacting feedback mechanisms in ice sheet, atmosphere solid Earth. Here we study long-term effects due to interplay competing melt–elevation glacial isostatic adjustment (GIA) feedbacks for different temperature step forcing experiments with coupled ice-sheet solid-Earth mode...

Men's health has been generalized as prostate cancer (PCa) with a supporting cast of other health issues, such as testicular cancer (TCa). As a result, research and scholarship in these supporting topical areas may not receive appropriate attention.This may possibly lead to disease burden indicators failing to comprehensively assess overall affect from a specific outcome within the population. ...