Normally it is sufficient to send the article to the appropriate journal, it is practice that they expect: This is an original! They evaluate it by peer rating. Sometimes it is necessary to change an original text by additional information or by a broader view of things or by a higher level, so that it could be accepted as an own work, independently from the first paper. Often it happens that the editorial staff send it back, with some justifications or advices; I think it is a process of adaption to figure out the conditions of acceptance gradually, when the author as scientist is sure, that his or her text is qualified.

Many thanks, Prof. Retter,

I know the general process as I have published quite a lot (both article and books). I was wondering what to do in this particular case, i.e. when I post texts on Research Gate.

I wonder if you can put that information in the box where your abstract goes. If you include a sentence indicating this fact at the beginning of your abstract, I think that should suffice.