Steerable reflector-assisted communication in obstructed line-of-sight FSO link with optimal mitigation of dust-induced signal fading

Photonic Network Communications - This paper introduces an effective technique for bridging free-space optical (FSO) communication between end-to-end nodes with obstructed direct line-of sight...     

Synthesis of achiral four-ring unsymmetrically substituted toluene derived liquid crystals with a polar end group

Achiral four-ring unsymmetrically substituted toluene-derived liquid crystals have been designed and synthesised by known and straightforward methods. All these compounds exhibit nematic phase over wide temperatures.     

CTAB promoted CuI catalyzed green and economical synthesis of 1,4-disubstituted-1,2,3-triazoles

A practical, straightforward, and highly efficient CuI mediated green protocol for the regioselective synthesis of 1,4-disubstituted-1,2,3-triazole was developed using cetyltrimethylammonium bromide as a cheap additive in good to excellent yields. Low catalyst loadings, environmentally friendly solvent, wide substrate scope and short reaction times at room temperature make this strategy more accessible and safe.     

Cobalt-Catalyzed C8-Dienylation of Quinoline-N-Oxides

An efficient Cp*Co^III-catalyzed C8-dienylation of quinoline-N-oxides was achieved by employing allenes bearing leaving groups at the α-position as the dienylating agents. The reaction proceeds by Co^III-catalyzed C−H activation of quinoline-N-oxides and regioselective migratory insertion of the allene followed by a β-oxy elimination, leading to overall dienylation. Site-selective C−H activation was achieved with excellent selectivity under mild reaction conditions, and 30 mol % of a NaF additive was found to be crucial for the efficient dienylation. The methodology features high stereoselectivity, mild reaction conditions, and good functional-group tolerance. C8-alkenylation of quinoline-N-oxides was achieved in the case of allenes devoid of leaving groups as coupling partners. Furthermore, gram-scale preparation and preliminary mechanistic experiments were carried out to gain insights into the reaction mechanism.     

Probe-Fed Hexagonal Ultra Wideband Antenna Using Flangeless SMA Connector

Wireless Personal Communications - An ultra wideband (UWB) antenna fed through a flangeless standard SMA connector near one of the vertices of hexagonal patch is introduced here, in this paper. The...     

EFFECT OF CHAIN LENGTH OF OXYETHYLENE GROUP ON PARTICLE SIZE AND ABSORPTION SPECTRA OF SILVER NANOPARTICLES PREPARED IN NON-IONIC WATER-IN-OIL MICRO EMULSIONS

The formation of silver nanoparticles by the method of reduction of silver ions by sodium borohydride in non-ionic water-in-oil microemulsion was investigated as a function of structure of the surfactant. Three types of non-ionic surfactants were selected differing in the chain length of the oxyethylene groups for example: NP-5, NP-9 and NP-11. The silver nanoparticles were characterized by UV-Visible Absorption Spectroscopy and Transmission Electron Microscopy. TEM. The results of this study showed that the panicle size is relatively smaller incase of NP-9 while for NP-5 and NP-11 the sizes are comparable. This obsevation is explained on the basis of structure of the droplets and the influence of Intermicellar exchange on nucleation and growth of particles.     

Cross-layer adaptive control for wireless mesh networks

This paper investigates optimal routing and adaptive scheduling in a wireless mesh network composed of mesh clients and mesh routers. The mesh clients are power constrained mobile nodes with relatively little knowledge of the overall network topology. The mesh routers are stationary wireless nodes with higher transmission rates and more capabilities. We develop a notion of instantaneous capacity regions, and construct algorithms for multi-hop routing and transmission scheduling that achieve network stability and fairness with respect to these regions. The algorithms are shown to operate under arbitrary client mobility models (including non-ergodic models with non-repeatable events), and provide analytical delay guarantees that are independent of the timescales of the mobility process. Our control strategies apply techniques of backpressure, shortest path routing, and Lyapunov optimization.     

Interpretation of chromatographic retentions of simple solutes with an amylose-based sorbent using infrared spectroscopy and DFT modeling

The interactions of amylose tris(3,5-dime- thylphenylcarbamate) (ADMPC, commercially “Chiralpak AD”) with 10 simple solutes—1-propanol, heptane, heptanol, benzene, propylbenzene, benzyl alcohol, pyridine, tetrahydrofuran, diethylamine, and aniline—are studied using attenuated total reflection infrared spectroscopy (ATR-IR) of thin polymer films, DFT modeling, and high performance liquid chromatography (HPLC). ATR-IR is used to determine the changes in the hydrogen bonding states of the C=O and NH groups of the polymer amide I and II bands upon absorption of each of the solutes at 25^∘C. DFT modeling with B3LYP/6-311+g(d,p) level of theory is used to predict the IR wavenumbers, the H-bonding interaction energies, and the hydrogen bonding distances of the polymer side-chains with certain solute molecules. The capacity factors of these solutes with ADMPC have been measured at 25^∘C in hexane/isopropanol (95/5, v/v) solvent. From IR data and DFT modeling, we conclude that the C=O and NH are key binding sites of the polymer and interact with the functional groups of various solutes. The capacity factors are understood on the basis of hydrogen bonding, hydrophobic, and dipole-dipole interactions of the C=O, NH, and phenyl groups of the sorbent with OH, NH, NH₂, O, phenyl, and N functional groups of the solutes.