نتایج جستجو برای: anthropogenic factor
تعداد نتایج: 867506 فیلتر نتایج به سال:
the core sediment samples were analysed for grain size, carbonates (caco3), organic carbon (oc) to obtain a preliminary view of its environmental conditions near point calimere along the southeast coast of vedaranyam, india.the high concentration of sand in the core is attributed to the tidal influence at the akkarapallivasal river mouth. the sea water which enters the river suspends the floccu...
in recent years, the topic of desertification has been discussed in different ways in scientific areas. this event occurred globally, regionally and nationally and many steps were taken to stop it. desertification is challenged universally and its destructive effects are unavoidable and its consequences do endanger the life of inhabitants. the identification of sensitive regions and prevention ...
Background and Objective: The aim of the present study was to investigate the concentration, enrichment factor, Nemrow integrated pollution index, and potential ecological risk of heavy metals including (Pb, Ni, Cu, Zn, Cd, V and Cr) in surface soils of Ahvaz oil filed. Materials and Methods: For this purpose, 49 soil samples with a systematic scheme from Ahvaz oil field were analyzed by atomi...
One of the most concerning issues to modern ecology and society is the ongoing loss of biodiversity. Ecosystems are now losing species at rates only seen in previous mass extinction events (Hails, 2008; Barnosky et al., 2011) with rates of extinction between 100 and 1000 times higher than pre-human levels (Pimm et al., 1995). This loss, in turn, is impairing the functioning of ecosystems (Worm ...
What one experiences today as atmosphere is a transient snapshot and result of its evolutionary history. Much of the development and present status was explained based both on scientific knowledge, and combined with established facts, even speculation. The planet Earth was formed around 4600 million years ago by the gravitational accretion of relatively small rocks and dust, within the solar ne...
Dangerous Anthropogenic Interference The United Nations Framework Convention on Climate Change (UNFCCC) commits signatory nations (which includes all major nations including the United States) to stabilizing greenhouse gas concentrations at levels short of DAI. To properly define DAI, one must take into account issues that are not only scientific, but, as I have argued elsewhere (2), economic, ...
All major rivers in northwestern Germany that flow into the North Sea, including the Weser River, display rare earth element (REE) patterns with large positive gadolinium (Gd) anomalies that indicate the presence of anthropogenic Gd derived from contrast agents used in magnetic resonance imaging. This microcontaminant cannot be removed by common sewage treatment technology and enters rivers and...
We estimated the oceanic inventory of anthropogenic carbon dioxide (CO2) from 1980 to 1999 using a technique based on the global chlorofluorocarbon data set. Our analysis suggests that the ocean stored 14.8 petagrams of anthropogenic carbon from mid-1980 to mid-1989 and 17.9 petagrams of carbon from mid-1990 to mid-1999, indicating an oceanwide net uptake of 1.6 and 2.0 +/- 0.4 petagrams of car...
The compositions of humic acids (HAs) isolated from cultivated and forested "Terra Preta de Indio" or Amazonian Dark Earth soils (anthropogenic soils) were compared with those from adjacent non-anthropogenic soils (control soils) using elemental and thermogravimetric analyses, and a variety of solid-state nuclear magnetic resonance techniques. The thermogravimetric index, which indicates the mo...
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