Both the author and myself have contacted him several times, without reply, so I'm now taking the opportunity to name both him and his journal. I do this in the hope that it will discourage potential authors from submitting papers to an operation that publishes plagiarised work and then refuses to even acknowledge the fact, let alone investigate it.
Advanced Modeling and Optimization is an "electronic international journal" edited by Neculai Andrei of the "Center for Advanced Modeling and Optimization" in Romania. It's rather obscure, but the fact that its content is freely-available means that papers it "publishes" will often be used in preference to others if authors have no access to better sources (one of the few down-sides of open access publishing).
As a result, the paper in question, containing swathes of our work, has attracted a fairly respectable 19 citations, including mentions in papers published in decent journals.
I would therefore ask you to consider this case before citing the following paper:
DNA Simulation of Nand Boolean Circuits. H. Ahrabian and A. Nowzari-Dalini.
Advanced Modeling and Optimization 6:2, 2004.
If you're thinking about submitting a paper to Advanced Modeling and Optimization (or even citing a paper in which it appears) I'd also ask you to consider the scientific credibility of the journal, given its lax reviewing and non-existent quality assurance processes.