In this paper, we investigate and characterize the effects of multi-channel and rendezvous protocols on the connectivity of dynamic spectrum access networks using percolation theory. In particular, we focus on the scenario where the secondary nodes have plenty of vacant channels to choose from a phenomenon which we define as channel abundance. To cope with the existence of multi-channel, we use two types of rendezvous protocols: naive ones which do not guarantee a common channel and advanced ones which do. We show that, with more channel abundance, even with the use of either type of rendezvous protocols, it becomes difficult for two nodes to agree on a common channel, thereby, potentially remaining invisible to each other. We model this in

The problem motivation of this work deals with how to control the network overhead and reduce the network latency that may cause many unwanted loops resulting from using standard routing. This work proposes three different wireless routing protocols which they are originally using some advantages for famous wireless ad-hoc routing protocols such as dynamic source routing (DSR), optimized link state routing (OLSR), destination sequenced distance vector (DSDV) and zone routing protocol (ZRP). The first proposed routing protocol is presented an enhanced destination sequenced distance vector (E-DSDV) routing protocol, while the second proposed routing protocol is designed based on using the advantages of DSDV and ZRP and we named it as

2(2-Tetrahydropyranylthio) methyl cyclopropyl amines were synthesized from allylmercaptan through several steps. The structures of the intermediates and the final products where confirmed through IR, NMR and elemental analysis, these compounds may be of value in the treatment of diseases  where free radicals are implicated in their pathogensis, since the thio and the amino groups of the synthesized compounds may act as free radical scavengers.

A silent film from Baghdad about love, war and poetry... _________________________ A new poetry book by the Iraqi poet Abdul Zahra Zaki has been published by Moment Books & Publications in an exclusively Digital Edition, entitled "Silent Film", and which subtitled "Poems of Blood, Bullets and Car Bombs", translated from the Arabic into English by Dr Adhraa A. Naser. This book is not trying to explain war, but simply to present it the way it is; the destruction it causes and the pain it leaves behind. For all who has changed forever because of war this book speaks the words of the killed and the killer. Zaki introduced the book with a line from his masterpiece The Hand Discovers describing the waves of bodies that stormed the country after t

Eugenol is found in essential oils of many plants. It belongs to a class of naturally occurring phenolic monoterpenoids, chemically it is an allyl chain-substituted guaiacol. A study was conducted on the compound of Eugenol, which included different studies. The first study was the determination of eugenol in body fluid, which includes serum, saliva and urine has been found the highest concentration was in urine then serum and saliva. The second study was the hematological study. Complete blood count was accomplished on the volunteers alredy administrated with eugenol contained mouthwash the analysis was accomplished before and after the mouth wash use. The result observed a slightly negative results and was not that significant, wh

W Tarik A, AW Ali T, Journal of the Faculty of Medicine, 2015 - Cited by 2