The main categories of organic pollutants are (a) Polycyclic aromatic hydrocarbons (PAHs) arise from incomplete combustion or pyrolysis of organic substances such as wood, carbon or mineral oil. Such combustion processes include food preparation in households and food shops; etc. and (b) Polychlorinated Biphenyls further subdivided in to two category for its sources as Directly manufactured PCBs used as hydraulic liquids(hydraulic oils), emollients for synthetic materials, lubricants, impregnating agents for wood and paper, flame protective substances, carrier substances for insecticides and in transformers and condensers, and The other main source of PCBs in the environment are combustion processes, from waste incineration plants, fossil fuel burning and to other incomplete combustion processes.
The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.
Last date updated on July, 2014