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.     

Trace determination of dexamethasone sodium phosphate in pharmaceutical formulations by differential pulse polarography

A simple and rapid differential pulse polarographic method has been developed for the trace determination of dexamethasone sodium phosphate. A well-defined single peak with an Ep value of -1.14 V is obtained in acetate buffer (pH 5.0). The linearity is valid in the range 0.2-1.2 mg/25 mL ( r=0.9992) with minimum detection limit of 7.6x10(-6) M. The precision of the method developed is implied from the values of relative mean deviation, standard deviation and coefficient of variation, which are 2.44%, 0.014 and 3.5% respectively. Marketed formulations of dexamethasone sodium phosphate have been analysed by calibration and standard addition methods. Recovery experiments were found to be quantitative, and analysis to determine the mass per tablet was obtained within +/-0.2% of the expected market value. The studies have shown that the method is reproducible and accurate and can be used in the analysis of marketed formulations.     

(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.     

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.     

Thermal characterization of NaNO3/KNO3 with different concentrations of Al2O3 and TiO2 nanoparticles

Journal of Thermal Analysis and Calorimetry - The thermo-physical properties of NaNO3/KNO3 (solar salt) added with Al2O3 and TiO2 nanoparticles as phase change material in thermal energy storage...