One of the central problems in migration measurement arises as a consequence of the different sources of migration data. Most information regarding migration is obtained from population censuses or population registers that report migration data for a given time interval. Another source of migration data is the sample survey which may be designed to provide information about both migrants and...

In China, 9Ð5% of the landmass is karst terrain and of that 47,000 km2 is located in semiarid regions. In these regions the karst aquifers feed many large karst springs within basins of thousands of square kilometres. Spring discharges reflect the fluctuation of ground water level and variability of ground water storage in the basins. However, karst aquifers are highly heterogeneous and monitor...

As CO(2) levels increase in the atmosphere, so too do they in the sea. Although direct effects of moderately elevated CO(2) in sea water may be of little consequence, indirect effects may be profound. For example, lowered pH and calcium carbonate saturation states may influence both deposition and dissolution rates of mineralized skeletons in many marine organisms. The relative impact of elevat...

Ž . At two caves Clamouse, S France and Ernesto, NE Italy , cave drip and pool waters were collected and sampled at intervals over a 2–3 year period. MgrCa and SrrCa concentration ratios, corrected for marine aerosols, are compared with those of bedrocks and, in some cases, aqueous leachates of soils and weathered bedrocks. Cave waters do not lie along mixing lines between calcite and dolomite ...

introduction in several perspectives including geographical determinism, possibilism, exceptionalism, ecological and other views, it is discussed about understanding how human and the environment interact. human in dealing with different environments, depending on the capabilities of environment and existing tools and techniques, adopt themselves with the nature or interfere in it. karst landsc...

The solubility, bioavailability and dissolution rate of drugs are important parameters for achieving in vivo efficiency. The bioavailability of orally administered drugs depends on their ability to be absorbed via gastrointestinal tract. For drugs belonging to Class II of pharmaceutical classification, the absorption process is limited by drug dissolution rate in gastrointestinal media. Therefo...