PageRank model of opinion formation on social networks

We propose the PageRank model of opinion formation and investigate its rich properties on real directed networks of the Universities of Cambridge and Oxford, LiveJournal, and Twitter. In this model, the opinion formation of linked electors is weighted with their PageRank probability. Such a probability is used by the Google search engine for ranking of web pages. We find that the society elite, corresponding to the top PageRank nodes, can impose its opinion on a significant fraction of the society. However, for a homogeneous distribution of two opinions, there exists a bistability range of opinions which depends on a conformist parameter characterizing the opinion formation. We find that the LiveJournal and Twitter networks have a stronger tendency to a totalitarian opinion formation than the university networks. We also analyze the Sznajd model generalized for scale-free networks with the weighted PageRank vote of electors.     

Electrochemical and photocatalytic investigation of nickel oxide for energy storage and wastewater treatment

Nickel oxide (NiO) was synthesized via a one-step facile method. X-ray diffraction analysis confirmed the face-centered cubic structure of NiO. The bonding nature and surface purity were confirmed via Fourier-transform infrared spectroscopy. NiO revealed partial spherical morphology with less particle aggregation. The optical bandgap of NiO was found to be 3.75 eV. Cyclic voltammetry revealed well-defined oxidation and reduction peaks for NiO. The charge–discharge curve exhibited specific capacitance of 184.6 F/g at current density of 0.3 A/g. NiO electrode exhibited longer cyclic stability of 93 % up to 1500 cycles. In addition, NiO + H₂O₂ revealed efficient photocatalytic degradation of methylene blue (organic pollutant) under visible-light irradiation with degradation efficiency of ~88 %. These results confirm that nanosized NiO is more suitable for dual application.

     

Move ordering and communities in complex networks describing the game of go

We analyze the game of go from the point of view of complex networks. We construct three different directed networks of increasing complexity, defining nodes as local patterns on plaquettes of increasing sizes, and links as actual successions of these patterns in databases of real games. We discuss the peculiarities of these networks compared to other types of networks. We explore the ranking vectors and community structure of the networks and show that this approach enables to extract groups of moves with common strategic properties. We also investigate different networks built from games with players of different levels or from different phases of the game. We discuss how the study of the community structure of these networks may help to improve the computer simulations of the game. More generally, we believe such studies may help to improve the understanding of human decision process.     

M...HNR interactions in imino-bound diaryltriazene complexes: structure and fluxionality

The nominally square-planar coordination of the d(8) complexes [MClL(1)L(2)(p-XC(6)H(4)NNNHC(6)H(4)X-p)](M = Rh, L(1)= L(2)= CO, X = H, Me, Et or F; M = Ir, L(1)= L(2)= CO, X = Me; M = Pd or Pt, L(1)= Cl, L(2)= PPh(3), X = Me; M = Pd, L(1)L(2)=eta(3)-C(3)H(5), X = Me), with the triazene N-bonded via the imine group, is supplemented by an axial M...H-N interaction involving the terminal amino group.     

(Triphos)Ni(eta2-BH4)]: an unusual nickel(I) borohydride complex

Reduction of [(triphos)NiCl2] (1) with an excess of NaBH4 in THF produces the paramagnetic Ni(I) complex [(triphos)Ni(eta2-BH4)] (2). X-ray crystallography shows 1 to be a square-planar Ni(II) species in which the phosphine ligand is bidentate, whereas 2 has pseudotetrahedral geometry at the Ni(I) center, with a tridentate phosphine and the borohydride ligand occupying a single coordination site. Density functional theory calculations show the unpaired electron in 2 to reside in an orbital located mainly on the Ni atom.     

Growth and characterization of an efficient semi organic single crystal: Sodium hydrogen oxalate monohydrate

A highly proficient nonlinear optical compound Sodium Hydrogen Oxalate Monohydrate (SHOM) single crystal under semi organic category has been grown-up by the process of slow solvent evaporation. The triclinic structure and cell parameters of SHOM was revealed from X-ray diffraction analysis. The examination of FTIR was done to determine the existence of various functional groups present in the SHOM crystal. The mechanical stability is evaluated from Vicker's microhardness tester and related mechanical parameters were assessed. The multiple shot laser damage threshold was examined to be 2.65 GW/cm². TG/DTA analysis is carried out to appraise the thermal limit of the grown material. The absorbance spectrum was analyzed from UV–vis analysis which verifies high transparency of the grown crystal and various optical constants were also estimated. The third order nonlinearity, two-photon absorption and self-defocussing effect of the grown material was established from the Z-Scan approach. The results favoring the materials suitability over nonlinear optical applications are reported.     

Third order nonlinear optical,spectral, dielectric,laser damage threshold,and photo luminescence characteristics of an efficacious semiorganic acentric crystal: L-Ornithine monohydrochloride

The efficient acentric L-ornithine monohydrochloride (LOMHCl), which belongs to the trait of semiorganic category and depicts nonlinear optical characteristics, was grown-up by the process of slow evaporation. The crystal structure and crystallinity of LOMHCl was established by the process of single crystal and powder X-ray diffraction. Single XRD affirm that LOMHCl crystallizes in the system of monoclinic with P2₁ as acentric space group. The examination of FTIR was done to ascertain the existence of various functional groups in LOMHCl. UV–Vis spectral analysis substantiates its optical quality and the optical constants were also assessed. Photoluminescence process elucidates its emission characteristics and its lifetime is also determined. LOMHCl discloses exquisite resistance to laser radiation having threshold up to 2.69 GW/cm². The SEM analysis highlights its surface topography. The mechanical stability has been attested by the analysis of microhardness and several mechanical parameters are also estimated. The investigation of dielectric characteristics of LOMHCl was also accomplished. The studies on second and third order nonlinearity were established by the method of Kurtz–Perry and Z-scan which facilitates its utility in the field of nonlinear optics.     

Chaotic dynamics of an asymmetrical gyrostat

The chaotic motions of an asymmetrical gyrostat, composed of an asymmetrical carrier and three wheels installed along its principal axes and rotating about the mass center of the entire system under the action of both damping torques and periodic disturbance torques, are investigated in detail in this paper. By introducing the Deprit's variables, one can derive the attitude dynamical equations that are well suited for the utilization of the Melnikov's integral developed by Wiggins and Shaw. By using the elliptic function theory, the homoclinic solutions of the attitude motion of a torque-free asymmetrical gyrostat are obtained analytically, based upon the Wangerin's method developed by Wittenburg. Transversal intersections of the stable and unstable manifolds (typically a necessary condition for chaotic motions to exist) are detected by the techniques of Melnikov's functions. The bifurcation curve between the compound parameters is depicted and discussed. By using a fourth-order Runge–Kutta integration algorithm as a tool of the numerical simulation, the long-term dynamical behavior of the system shows that the technique of the Melnikov's function could successfully be employed to predict the compound physical parameters that correspond to the chaotic dynamical motions of an asymmetrical gyrostat.     

Growth,optical, photoluminescence,dielectric, second and third order nonlinear optical studies of benzoyl valine acentric crystal

A nonlinear optical material benzoyl valine (BV) was synthesized by the technique of slow evaporation process at room temperature. The single crystal X ray diffraction analysis evince that crystal corresponds to acentric space group P₂₁ with monoclinic system. The diverse optical properties assured an elevated transparency in BV crystal. Photoluminescence profile revealed the suitability of crystal for fabricating violet lasers. The Laser damage threshold and the dielectric behavior of the grown crystal were analyzed to indicate its practical applications. The second and third order nonlinear optical measurements were studied to prove its potentiality in the domain of nonlinear optical applications.