Peripheral Routing Protocol – a new routing protocol proposal for a realistic WSN mobility model

Wireless sensor networks (WSNs) are changing our way of life just as the internet has revolutionized the way people communicate with each other. Future wireless networks are envisioned to be robust, have simple and efficient communication between nodes and self-organizing dynamic capabilities. When new nodes join in, a self-configuring network has to have the ability to include these nodes in its structure in real time, without human or machine interference. The need for a destination node (D) which moves at the periphery of wireless sensor networks can be argued from different points of view: the first is that different WSN scenarios require data gathering in such a way; the second point is that this type of node movement maximizes network lifetime because it offers path diversity preventing the case where the same routes are used excessively. However the peripheral movement model of the mobile destination does not resemble any mobility models presented in the WSN literature. In this thesis a new realistic WSN sink mobility model entitled the “Marginal Mobility Model” (MMM) is proposed. This was introduced for the case when the dynamic destination (D), moving at the periphery, frequently exits and enters the WSN coverage area. We proved through Qualnet simulations that current routing protocols recommended for Mobile Ad Hoc Networks (MANETs) do not support this sink mobility model. Because of this, a new routing protocol is proposed to support it called the Peripheral Routing Protocol (PRP). It will be proven through MATLAB simulations that, for a military application scenario where D’s connectivity to the WSN varies between 10%-95%, compared with the 100% case, PRP outperforms routing protocols recommended for MANETs in terms of throughput (T), average end to end delay (AETED) and energy per transmitted packet (E). Also a comparison will be made between PRP and Location-Aided Routing (LAR) performance when D follows the MMM. Analytical models for both PRP and LAR are proposed for T and E. It is proved through MATLAB simulations that, when compared with LAR, PRP obtains better results for the following scenarios: when the WSN size in length and width is increased to 8000 m and one packet is on the fly between sender and sink, PRP sends 103% more data and uses 84% less energy; when more data packets are on the fly between sender and sink, PRP sends with 99.6% more data packets and uses 81% less energy; when the WSN density is increased to 10,000 nodes PRP uses 97.5% less energy; when D’s speed in increased to 50 Km/h, PRP sends 74.7% more data packets and uses 88.4% less energy

Surveying Position Based Routing Protocols for Wireless Sensor and Ad-hoc Networks

A focus of the scientific community is to design network oriented position-based routing protocols and this has resulted in a very high number of algorithms, different in approach and performance and each suited only to particular applications. However, though numerous, very few position-based algorithms have actually been adopted for commercial purposes. This article is a survey of almost 50 position-based routing protocols and it comes as an aid in the implementation of this type of routing in various applications which may need to consider the advantages and pitfalls of position-based routing. An emphasis is made on geographic routing, whose notion is clarified as a more restrictive and more efficient type of position-based routing. The protocols are therefore divided into geographic and non-geographic routing protocols and each is characterized according to a number of network design issues and presented in a comparative manner from multiple points of view. The main requirements of current general applications are also studied and, depending on these, the survey proposes a number of protocols for use in particular application areas. This aims to help both researchers and potential users assess and choose the protocol best suited to their interest

Biocatalytic Strategy for Grafting Natural Lignin with Aniline

This paper presents an enzyme biocatalytic method for grafting lignin (grafting bioprocess) with aniline, leading to an amino-derivatized polymeric product with modified properties (e.g., conductivity, acidity/basicity, thermostability and amino-functionalization). Peroxidase enzyme was used as a biocatalyst and H2O2 was used as an oxidation reagent, while the oxidative insertion of aniline into the lignin structure followed a radical mechanism specific for the peroxidase enzyme. The grafting bioprocess was tested in different configurations by varying the source of peroxidase, enzyme concentration and type of lignin. Its performance was evaluated in terms of aniline conversion calculated based on UV-vis analysis. The insertion of amine groups was checked by 1H-NMR technique, where NH protons were detected in the range of 5.01–4.99 ppm. The FTIR spectra, collected before and after the grafting bioprocess, gave evidence for the lignin modification. Finally, the abundance of grafted amine groups was correlated with the decrease of the free –OH groups (from 0.030 to 0.009 –OH groups/L for initial and grafted lignin, respectively). Additionally, the grafted lignin was characterized using conductivity measurements, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), temperature-programmed desorption (TPD-NH3/CO2) and scanning electron microscopy (SEM) analyses. The investigated properties of the developed lignopolymer demonstrated its disposability for specific industrial applications of derivatized lignin

One-Pot Enzymatic Production of Lignin-Composites

A novel and efficient one-pot system for green production of artificial lignin bio-composites has been developed. Monolignols such as sinapyl (SA) and coniferyl (CA) alcohols were linked together with caffeic acid (CafAc) affording a polymeric network similar with natural lignin. The interaction of the dissolved SA/CA with CafAc already bound on a solid support (SC2/SC6-CafAc) allowed the attachment of the polymeric product direct on the support surface (SC2/SC6-CafAc-L1 and SC2/SC6-CafAc-L2, from CA and SA, respectively). Accordingly, this procedure offers the advantage of a simultaneous polymer production and deposition. Chemically, oxi-copolymerization of phenolic derivatives (SA/CA and CAfAc) was performed with H2O2 as oxidation reagent using peroxidase enzyme (2-1B mutant of versatile peroxidase from Pleurotus eryngii) as catalyst. The system performance reached a maximum of conversion for SA and CA of 71.1 and 49.8%, respectively. The conversion is affected by the system polarity as resulted from the addition of a co-solvent (e.g., MeOH, EtOH, or THF). The chemical structure, morphology, and properties of the bio-composites surface were investigated using different techniques, e.g., FTIR, TPD-NH3, TGA, contact angle, and SEM. Thus, it was demonstrated that the SA monolignol favored bio-composites with a dense polymeric surface, high acidity, and low hydrophobicity, while CA allowed the production of thinner polymeric layers with high hydrophobicity

Image3_One-Pot Enzymatic Production of Lignin-Composites.tif

<p>A novel and efficient one-pot system for green production of artificial lignin bio-composites has been developed. Monolignols such as sinapyl (SA) and coniferyl (CA) alcohols were linked together with caffeic acid (CafAc) affording a polymeric network similar with natural lignin. The interaction of the dissolved SA/CA with CafAc already bound on a solid support (S_C2/S_C6-CafAc) allowed the attachment of the polymeric product direct on the support surface (S_C2/S_C6-CafAc-L₁ and S_C2/S_C6-CafAc-L₂, from CA and SA, respectively). Accordingly, this procedure offers the advantage of a simultaneous polymer production and deposition. Chemically, oxi-copolymerization of phenolic derivatives (SA/CA and CAfAc) was performed with H₂O₂ as oxidation reagent using peroxidase enzyme (2-1B mutant of versatile peroxidase from Pleurotus eryngii) as catalyst. The system performance reached a maximum of conversion for SA and CA of 71.1 and 49.8%, respectively. The conversion is affected by the system polarity as resulted from the addition of a co-solvent (e.g., MeOH, EtOH, or THF). The chemical structure, morphology, and properties of the bio-composites surface were investigated using different techniques, e.g., FTIR, TPD-NH₃, TGA, contact angle, and SEM. Thus, it was demonstrated that the SA monolignol favored bio-composites with a dense polymeric surface, high acidity, and low hydrophobicity, while CA allowed the production of thinner polymeric layers with high hydrophobicity.</p

Image2_One-Pot Enzymatic Production of Lignin-Composites.tif

<p>A novel and efficient one-pot system for green production of artificial lignin bio-composites has been developed. Monolignols such as sinapyl (SA) and coniferyl (CA) alcohols were linked together with caffeic acid (CafAc) affording a polymeric network similar with natural lignin. The interaction of the dissolved SA/CA with CafAc already bound on a solid support (S_C2/S_C6-CafAc) allowed the attachment of the polymeric product direct on the support surface (S_C2/S_C6-CafAc-L₁ and S_C2/S_C6-CafAc-L₂, from CA and SA, respectively). Accordingly, this procedure offers the advantage of a simultaneous polymer production and deposition. Chemically, oxi-copolymerization of phenolic derivatives (SA/CA and CAfAc) was performed with H₂O₂ as oxidation reagent using peroxidase enzyme (2-1B mutant of versatile peroxidase from Pleurotus eryngii) as catalyst. The system performance reached a maximum of conversion for SA and CA of 71.1 and 49.8%, respectively. The conversion is affected by the system polarity as resulted from the addition of a co-solvent (e.g., MeOH, EtOH, or THF). The chemical structure, morphology, and properties of the bio-composites surface were investigated using different techniques, e.g., FTIR, TPD-NH₃, TGA, contact angle, and SEM. Thus, it was demonstrated that the SA monolignol favored bio-composites with a dense polymeric surface, high acidity, and low hydrophobicity, while CA allowed the production of thinner polymeric layers with high hydrophobicity.</p