RVCloud: a routing protocol for vehicular ad hoc network in city environment using cloud computing

Routing in Vehicular Ad hoc Network (VANET) is a challenging task due to high mobility of vehicles. In this paper, a RVCloud routing protocol is proposed for VANET to send the data efficiently to the destination vehicle using cloud computing technology. In this protocol, vehicle beacon information is send to the cloud storage through the Road Side Unit (RSU). As vehicles have less storage and computing facility, the information of all the vehicles moving in the city is maintained by the cloud. Source vehicle sends the data to the destination by sending the data to the nearby RSU. After receiving the data, RSU sends a request to the cloud for an optimal RSU information, that takes minimum packet forwarding delay to send the data to the destination. Cloud provides location service by providing destination location and optimal RSU information. Then RSU sends the data to the optimal RSU using internet. By using the internet facility, packet forwarding delay and link disruption problem are reduced. Simulation results show that, RVCloud performs better than VehiCloud, P-GEDIR, GyTAR, A-STAR, and GSR routing protocols.     

Benefits of sliceable photonic-based transponders in metro and long-haul networks

The multicast paradigm offers tremendous benefits in efficiency for transmitting data across optical networks, allowing a single client to send information to an entire set of endpoints. A multicast request is most efficiently provisioned through the creation of a tree, with the endpoints, or resources, occasionally serving as branching points. This practice can lead to the source of the request becoming disconnected from the associated resources should one of those branching resources fail. In cases where a large amount of data are currently in transmission, the ramifications of this failure can be severe. We propose an optimal solution through integer linear programming for the static protected multicast routing and wavelength assignment problem, where an entire set of requests is provisioned with built-in redundancy against single resource node failure. We compare the optimal performance against several heuristics and find that protection against this type of failure can be provided with the trade-off of increased wavelength consumption, compared to less-protected solutions.     

Critical Evaluation and Thermodynamic Modeling of the MgO–MnO–Mn2O3–SiO2 System

A complete literature review, critical evaluation, and thermodynamic optimization of phase diagrams and thermodynamic properties of the MgO–MnO–Mn₂O₃–SiO₂ system at 1 atm pressure are presented. The molten oxide phase was described by the Modified Quasichemical Model considering the short‐range ordering in molten oxide, and the Gibbs energies of solid solutions were described using the Compound Energy Formalism considering the crystal structure of each solid solution. A set of optimized model parameters of all phases was obtained which reproduces all available and reliable thermodynamic data and phase diagrams within experimental error limits from 25°C to above the liquidus temperatures over the entire range of composition under the oxygen partial pressures from metallic saturation to 1 atm. The database of the model parameters can be used along with software for the Gibbs energy minimization to calculate any phase diagram section and thermodynamic property within the present system.     

Theoretical Approaches on the Synergistic Interaction between Double-Headed Anionic Amino Acid-Based Surfactants and Hexadecyltrimethylammonium Bromide

Theoretical investigations on the micellization of mixtures of (i) amino acid-based anionic surfactants [AAS: N-dodecyl derivatives of aminomalonate, −aspartate, and -glutamate] and (ii) hexadecyltrimethylammonium bromide (HTAB), were carried out at different mole ratios. Variation in the theoretical values of critical micelle concentration (CMC), mole fraction of surfactants in the micellar phase (X), at the interface (X^σ), interaction parameters at the bulk/interface (β^R/β^σ), ideality/nonideality of the mixing processes, and activity coefficients (f) were evaluated using Rubingh, Rosen, Motomora, and Sarmoria-Puvvada-Blankschtein models. CMC values significantly deviate from the theroretically calculated values, indicating associative interaction. With increasing mole fraction of AAS (α_AAS), the magnitude of the (β^R/β^σ) values gradually decreased, considered to attributable to hydrophobic interactions. With increasing α_AAS, the micellar mole fraction of HTAB (X₂) decreased insignificantly and X₂ values were higher than those compared to AAS for all combinations, due to the dominance of HTAB in micelles. Micellar mole fraction at the ideal state of AAS () differed from micellar mole fraction of AAS (X₁), indicating nonideality in the mixed micellization process. Gibbs free energy of micellization ( ∆G_m ) values are more negative than the free energy of micellization for ideal mixing (), indicating the micellization process is spontaneous. With increasing α_AAS, the enthalpy of micellization (ΔH_m) and entropy of micellization (ΔS_m) values gradually increased, which indicates micellization is exothermic. The different physicochemical parameters of the mixed micelles are correlated with the variation in the spacer length between the two carboxylate groups of AAS.     

Electro-kinetically enhanced mass transport of charged macro-solutes through a microchannel with porous walls

Electrokinetics of the solute transport across the porous walls of micro channel is important from its practical application but less explored. Transport of the charged macro-solutes across perm-selective walls in a microchannel is investigated. The extended Nernst–Planck equation describes the charged macro-solutes distribution in the mass transfer boundary layer over the porous wall. The transverse electromigration of the charged macro-solute either augments or suppresses the concentration polarization and the permeation rate depending on the wall and solute surface potential (attractive or repelling). The wall potential is screened due to the electrical double layer interaction of the wall and charged solute. It is observed that the charged solute concentration over the channel wall enhances by two times in case of oppositely charged interactions (unlike solute and channel wall) compared to like charges. The findings of this study can facilitate understanding of electrokinetic based drug delivery and separation systems involving charged solutes.     

Epoxy/p‐phenylenediamine functionalized graphene oxide composites and evaluation of their fracture toughness and tensile properties

In an attempt to enhance the mechanical properties of epoxy/graphene‐based composites, the interface was engineered through the functionalization of graphene oxide (GO) sheets with p‐phenylenediamine; this resulted in p‐phenylenediamine functionalized graphene oxide (GO–pPDA). The morphology and chemical structure of the GO–pPDA sheets were studied by spectroscopic methods, thermal analysis, X‐ray diffraction, and transmission electron microscopy. The characterization results show the successful covalent functionalization of GO sheets through the formation of amide bonds. In addition, p‐phenylenediamine were polymerized on graphene sheets to form crystalline nanospheres; this resulted in a GO/poly(p‐phenylenediamine) hybrid. The mechanical properties of the epoxy/GO–pPDA composite were assessed. Although the Young's modulus showed improvement, more significant improvements were observed in the strength, fracture strain, and plane‐strain fracture toughness. These improvements were attributed to the unique microstructure and strong interface between GO–pPDA and the epoxy matrix. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43821.     

Critical Evaluation and Thermodynamic Modeling of the Mg–Mn–O (MgO–MnO–MnO2) System

All phase diagram and thermodynamic data of the MgO–MnO and MgO–MnO–MnO₂ systems were critically evaluated and thermodynamically optimized to obtain one set of thermodynamic model parameters. The MgMn₂O₄–Mn₃O₄ spinel solutions were modeled with two sublattices Compound Energy Formalism by considering the cation distribution between tetrahedral and octahedral sites. The slag phase and monoxide solid solution were also described using the Modified Quasichemical Model and Bragg–Williams random mixing model, respectively. The optimized thermodynamic model parameters can be used with a Gibbs energy minimization routine to calculate the phase diagram and thermodynamic properties of the system at oxygen partial pressures between metal saturation and 1 atm.     

Influence of Oxygen Annealing in the Superconductivity and Electronic States of Mo0.3Cu0.7Sr2YCu2O y

We report the effect of oxygen-annealing in the superconductivity and electronic states for the Mo_0.3Cu_0.7Sr₂YCu₂O _y compound. The influence of oxygen annealing in the electronic states for Mo_0.3Cu_0.7Sr₂YCu₂O _y associated with a nonsuperconducting to superconducting state transformation has been investigated by means of X-ray photoelectron spectroscopy, powder X-ray diffraction, magnetic susceptibility, and resistivity measurements. We unambiguously show the preeminence of the Mo^V state over the Mo^VI one; annealing under an oxygen atmosphere enhances both the Mo^VI and Cu^II amounts. The enhancement of Mo^VI after oxygen annealing is in close relation with the decrease in the O 2p→Cu 3d charge-transfer energy resulting in superconducting properties. Oxygen annealing is then seemed to reduce the copper plane hole concentration of the overdoped as-prepared sample, which induces superconductivity in the Cu–O planes.     

Rhodium‐Catalyzed Enantioselective Conjugate Addition of Arylboronic Acids to Dihydronitronaphthalenes

A highly enantioselective (up to 91% ee) rhodium‐catalyzed asymmetric addition of arylboronic acids has been achieved leading to the challenging dihydro‐3‐nitronaphthalenes using one equivalent of phosphoramidite ligand to rhodium catalyst. A concise formal asymmetric synthesis of the dopamine D1 agonist, dihydrexidine was accomplished using the method.