in this paper, a certain new connectedness of l-fuzzy subsets inl-topological spaces is introduced and studied by means of preclosed sets. itpreserves some fundamental properties of connected set in general topology.especially the famous k. fan’s theorem holds.

For various reasons, some of them linked to the evolution historiography Chemistry, many recognized and important chemists in their time – ours, because legacy they left are relegated degree oblivion. One these chemists, dead just over 200 years ago, is Martin Heinrich Klaproth (1743-1817), a key figure transition from phlogiston theory Lavoisier’s new chemistry one creators modern analytical c...