Controllability of Fractional Order Stochastic Differential Inclusions with Fractional Brownian Motion in Finite Dimensional Space

In this paper, sufficient conditions are formulated for controllability of fractional order stochastic differential inclusions with fractional Brownian motion (fBm) via fixed point theorems, namely the Bohnenblust-Karlin fixed point theorem for the convex case and the Covitz-Nadler fixed point theorem for the nonconvex case. The controllability Grammian matrix is defined by using Mittag-Leffler matrix function. Finally, a numerical example is presented to illustrate the efficiency of the obtained theoretical results.      

Star poly(4-vinylpyridine)s using dendritic ATRP initiators: Synthesis,electrolyte property and performance in dye sensitized solar cell

The G0 and G1 polyurethane dendrimers terminated with 3–12 atom transfer radical polymerization (ATRP) initiators were prepared using single and dual functional ATRP reagents and their structures were confirmed using FT-IR, ¹H–NMR, HR-MS and SEC-MALLS techniques. 4-Vinylpyridine was polymerized using the G1 dendritic initiators to obtain six- and twelve-arm star poly(4-vinylpyridine)s (STAR-P1 and STAR-P2). The absolute molecular weight and PDI of star polymers were in the order of 10⁵ and 1.23–1.24 respectively. Hydrolysis leading to degradation of inner polyurethane core of the star polymers yielded more narrow dispersed poly(4-vinylpyridine) chains and the SEC-MALLS data of these chains confirm the accurate control on number of arms. Both of the polymers were doped with KI/I₂ along with N3-dye to work as efficient polymer electrolytes for dye sensitized solar cell (DSSC). The increment in the conductivity of doped STAR-P1 was very significant and reached 2.415 mS/m from 0.0066 mS/m of dopant salt. The current-voltage characteristics of these doped polymer electrolytes measured under simulated sun light with AM 1.5 at 40 mW/cm² yielded energy conversion efficiency (η) of 5.13% and 1.90% for STAR-P1 and STAR-P2 respectively and these values also significantly high compared to 1.09% corresponds to current-voltage curve of the device fabricated without the polymers.

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Graphical abstract Star poly(4-vinylpyridine)s were prepared using novel dendritic ATRP initiators and used as electrolytes for dye sensitized solar cell (DSSC); one of the cells showed 5.13% energy conversion efficiency.

     

Synthesis,spectral, structural,Hirshfeld surface and DFT studies on bis(N-(4-fluorobenzyl)-N-(2-phenylethyl)dithiocarbamato-S,S′)zinc(II) and its use for the preparation of ZnS and ZnO nanoparticles

Two new complexes, bis(N-(2-phenylethyl)-N-(4-fluorobenzyl)dithiocarbamato-S,S′)zinc(II) (1) and bis(N-(2-phenylethyl)-N-(4-chlorobenzyl)dithiocarbamato-S,S′)zinc(II) (2), have been synthesized and characterized by various physicochemical techniques. Structure of 1 has been determined by single crystal X-ray diffraction. Complex 1 is a dimer. Zinc atom is four coordinated with a distorted tetrahedral environment. Geometry optimization, geometrical parameters, molecular electrostatic potential (MEPs) and frontier molecular orbital analysis of dimeric and monomeric structures of 1 have been carried out by DFT methods and compared with the experimental X-ray diffraction data. The noncovalent interactions in the complex 1 have been analyzed using Hirshfeld surface analysis. 1 and 2 have been used as single source precursors for the preparation of zinc sulfide and zinc oxide nanoparticles. As-prepared zinc sulfides and zinc oxides have been characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), UV–vis absorption, photoluminence and energy dispersive X-ray spectroscopy (EDS). X-ray diffraction study reveals that zinc sulfides and zinc oxides are composed of rhombohedral and hexagonal phases, respectively. Photocatalytic activities of zinc sulfides and zinc oxides were evaluated by degradation of rhodamine B in aqueous solution under UV light irradiation. The results demonstrated the capability of zinc sulfides and zinc oxides as photocatalyst under UV irradiation to degrade the dye.     

Device for oxide dots fabrication with copper wire as cathode probe

A device has been fabricated to perform large area local oxidation with copper wire (thickness 7 μm) as cathode probe. Ability of this device was studied, by silicon oxide (SiO₂) dots fabrication on silicon (Si) surface and patterning of model microorganism, Mycobacterium smegmatis on the predetermined positions (oxide dots) with preferable surface monolayer. Positive patterning of Mycobacterium smegmatis attained on the fabricated substrate due to the charge difference between SiO₂ dot and Si surface, which was confirmed by atomic force microscopy and scanning electron microscopy (SEM) analysis. This device shows possibilities of overcoming the inherent limitations of large area local oxidation by AFM.     

Nucleic Acid Binding and Invitro Cytotoxicity Studies of Polymer Grafted Intercalating Copper(II) Complex

The present study on interaction of a polymer-copper(II) complex, [Cu(dpqC)₂(BPEI)](ClO₄)₂·H₂O (dpqC = dipyrido[3,2-a:2′,3′-c](6,7,8,9-tetrahydro) phenazine) with CT-DNA/yeast tRNA were performed by using various spectroscopic methods. The data from these experiments suggest that the polymer-copper(II) complex binds to CT-DNA/yeast tRNA through intercalation. Furthermore, our polymer copper(II) complex showed strong binding ability with yeast tRNA than CT-DNA. It indicates that structural differences of the nucleic acids play a significant role in the binding affinity. The antiproliferative and cell death properties of this complex have been tested against MDA-MB-231 breast cancer cell line by various specific staining methods. These obtained results indicate that our complex is more cytotoxic to MDA-MB-231 breast cancer cell line.     

Performance of novel hyperbranched poly(aryl‐ether‐urea)s doped with N3‐dye in nanocrystalline DSSC

An amine‐terminated hyperbranched poly(aryl‐ether‐urea) (HBPEU) was prepared from an AB₂‐type blocked isocyanate monomer and then its end groups were modified into urea (M‐HBPEU) by reaction with phenyl isocyanate. Both of the polymers were doped with N3‐dye along with KI/I₂ to work as efficient polymer electrolytes in nanocrystalline dye sensitized solar cell. The increment in the conductivity of doped HBPEU and doped M‐HBPEU was very significant and reached its value at 8.2 × 10⁻³ and 4.1 × 10⁻² S/cm, respectively. The current–voltage (I–V) characteristics of these two doped polymers measured under simulated sunlight with AM 1.5 at 60 mW/cm² generate photocurrent of 2.5 and 3.6 mA/cm², together with a photo voltage of 690 and 750 mV, and fill factor of 0.55 and 0.61 yielding a overall energy conversion efficiency of 2.4% and 4.1%, respectively. These results suggest that M‐HBPEU show better cell performance and conductance properties than the HBPEU. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40408.     

A Centralized Mechanism for Preventing DDOS Attack in Wireless Sensor Networks

Wireless sensor networks face numerous limitations. Security and Privacy are the two most essential parameters that require consideration in wireless sensor networks for conveying responsive information amid basic applications. High density and limited communication range of sensor nodes, forwarding packets in sensor networks have caused the performance of during multi-hop data transmission. Hence communication with different devices these days are not secure, due to the absence of centralized monitoring and overprotective requirements. This paper is related to speak about Distributed Denial of Service which debilitates the ability of the network and the data being transmitted. The earlier system guarantees the WSN through a self arranged and confined procedure between the nodes in the sensor environment. Here, the authors present the Centralized Detect Eliminate and Control algorithm for authorization and centralized monitoring component to discover the node that has turned into a victim node and to get rid of the information communicated to the fatality node from the neighbour nodes. Overprotective of the communication between the nodes leads to dependability. The simulation results improve the malicious node detection rate and increase the various parameters like throughput and reduce the average delay. This leads to, the overall detection rate built, eventually enhancing the parameters of the network environment.

     

Effect of functionlization of N,N-dibenzyldithiocarbamate: synthesis,spectral and structural studies on bis(N-benzyl-N-(4-methoxybenzyl)dithiocarbamato-S,S′)zinc(II) and bis(N-benzyl-N-(4-cholrobenzyl)dithiocarbamato-S,S′)cadmium(II) and their use for the preparation of MS (M = Zn,Cd)

Bis(N-benzyl-N-(4-methoxybenzyl)dithiocarbamato-S,S′)zinc(II) (1) and bis(N-benzyl-N-(4-chlorobenzyl)dithiocarbamato-S,S′)cadmium(II) (2) have been prepared and characterized by elemental analysis, IR and NMR (¹H and ¹³C) spectroscopy and single-crystal X-ray analysis. Complexes 1 and 2 exist as monomer and dimer, respectively. Crystal structures of 1 and 2 confirm the presence of four coordinated zinc in a distorted tetrahedral arrangement and five coordinated cadmium in a distorted square pyramid arrangement, respectively. Both the complexes are further stabilized by various interactions such as C–H···S, C–H···N, C–H···O and C–H···π (chelate). C–H···O interaction leads to the formation of dimer in complex 1. In complex 2, C–H···π (chelate) interaction runs in opposite directions which results in the polymeric chain. ZnS and CdS have been prepared from 1 and 2, respectively, and characterized by powder X-ray diffraction, SEM, UV–Vis and fluorescence spectroscopy. The X-ray diffraction pattern confirms the wurtzite phase of as-prepared ZnS and CdS.