the streptomycetes are gram positive bacteria with a filamentous form that present in a wide variety of soil including composts, water and plants. the most characteristic of streptomycetes is the ability to produce secondary metabolites such as antibiotics. they produce over two-thirds of the clinically useful antibiotics of natural origin (e.g., neomycin and chloramphenicol. another characteri...

In this paper, we consider two single server queueing systems to which customers of distinct priorities (P1 and P2) arrive according a Marked Markovian arrival process (MMAP). They are served phase type distributions. The probability P1 customer feedback is θ on completion his service. (P1) customers, as well P2 join the low priority queue. Low (P2) taken for service from head line whenever que...