Fluctuation study of pionisation in ultrarelativistic nucleus-nucleus interaction

The scaled factorial moments and the multifractal moments have been investigated in differentη-intervals to study the dynamical fluctuation of pions produced in 200 AGeV³²S-Ag/Br interaction. In order to investigate the detail characteristics of intermittency behaviour, theF-moments are extracted up to the eighth order of moments in differentM-intervals. The analysis indicates a non-thermal phase transition and different regime of particle production during the hadronisation process.     

Vanadium(III) complexes of salicylaldehyde thiosemicarbazones

Hexacoordinate complexes of vanadium(III) containing tridentate ONS chelating substituted salicylaldehyde thiosemicarbazones have been prepared and characterised by elemental analysis, i.r. and u.v.–vis. spectroscopy and cyclic voltammetry.     

Fluctuation study of pionisation in ultrarelativistic nucleus-nucleus interaction

The scaled factorial moments and the multifractal moments have been investigated in different??-intervals to study the dynamical fluctuation of pions produced in 200 AGeV³²S-Ag/Br interaction. In order to investigate the detail characteristics of intermittency behaviour, theF-moments are extracted up to the eighth order of moments in differentM-intervals. The analysis indicates a non-thermal phase transition and different regime of particle production during the hadronisation process.     

Correlation between Dynamic Heterogeneity and Local Structure in a Room‐Temperature Ionic Liquid: A Molecular Dynamics Study of [bmim][PF6]

The complex dynamics of a room‐temperature ionic liquid, 1‐n‐butyl‐3‐methylimidazolium hexafluorophosphate ([bmim][PF₆]), is studied using equilibrium classical molecular dynamics simulations in the temperature range of 250–450 K. The activation energies for the self‐diffusion of ions are around 30–34 kJ mol^?1, with that of the anion a little higher than that for the cation. The electrical conductivity of the liquid is calculated and good agreement with experiments is obtained. Structural relaxation is studied through the decay of coherent (total density–density correlation) and incoherent (self part of density–density correlation) intermediate scattering functions over a range of temperatures and wave vectors relevant to the system. The relaxation data are used to identify and characterize two processes, α and β. The dependence of the two relaxation times on temperature and wave vector is obtained. The dynamical heterogeneity of the ions determined through the non‐Gaussian parameter indicates the motion of the cation to be more heterogeneous than that of the anion. The faster ones among the cations are coordinated to faster anions, while slower cations are surrounded predominantly by slower anions. Thus, the dynamical heterogeneity in this ionic liquid is shown to have structural signatures.     

Bonding potential between two12C nuclei

The potential between two¹²C nuclei in linear chain configuration has been calculated microscopically using the Ali-Bodmerα-α potential. This potential shows a pocket and compares well in the tail region with the phenomenological potential extracted before, from the data on the quasi-molecular resonances of the¹²C +¹²C system. This provides support to the diatomic like rotation-vibration picture of quasi-molecular states.     

Dissipative Waves in a Relaxing Gas Exhibiting Mixed Nonlinearity

We consider a weakly dissipative quasilinear system of PDEs, governingthe unsteady one-dimensional motion of a relaxing gas, and investigatethe effects ofhigher order terms and the source term, present in the differentialsystem, on the wave motion associated with it. The undisturbed stateof the medium, which is assumed to be uniform and at restadmits mixed nonlinearity, i.e., the quadratic nonlinearity parameter inherent in the system changes sign depending on the basestate. The method of multiple scales is employed to determine theevolution equation governing small perturbations to the state where is of O(), and the effects of nonlinearity arenoticeable over times of order O(^–2).     

Antibacterial behaviour of quaternized poly(vinyl chloride)-g-poly(4-vinyl pyridine) graft copolymers

Amphiphilic graft copolymers consisting of poly(vinyl chloride)(PVC) main chains and poly(4-vinyl pyridine)(P4VP) side chains were synthesized via atom transfer radical polymerization(ATRP) using direct initiation of chlorine atoms. The successful synthesis of PVC-g-P4 VP graft copolymers was confirmed by Fourier transform infrared spectroscopy(FTIR) and proton nuclear magnetic resonance(1H-NMR). Transmission electron microscope(TEM) and small angle X-ray scattering(SAXS) analysis showed that PVC-g-P4 VP exhibited microphase-separated, ordered structure with 37.6 nm of domain spacing, which was not observed in neat PVC. For antibacterial applications, the tertiary nitrogen atoms of PVC-gP4 VP was quaternized using 1-bromohexane, as confirmed by FTIR measurements. Bacteria including Escherichia coli(E. coli), Staphylococcus aureus(S. aureus), Bacillus cereus(B. cereus), and Pseudomonas aeruginosa(P. aeruginosa) were completely killed in 24 h on the quaternized PVC-g-P4VP(46% grafting) surface, indicating its excellent antibacterial behavior while it showed to be cytotoxic to mammalian cell.     

Tuning the Redox Properties of a Nonheme Iron(III)–Peroxo Complex Binding Redox‐Inactive Zinc Ions by Water Molecules

Redox‐inactive metal ions play important roles in tuning chemical properties of metal–oxygen intermediates. Herein we report the effect of water molecules on the redox properties of a nonheme iron(III)–peroxo complex binding redox‐inactive metal ions. The coordination of two water molecules to a Zn²⁺ ion in (TMC)Fe^III‐(O₂)‐Zn(CF₃SO₃)₂ ( 1 ‐Zn²⁺) decreases the Lewis acidity of the Zn²⁺ ion, resulting in the decrease of the one‐electron oxidation and reduction potentials of 1 ‐Zn²⁺. This further changes the reactivities of 1 ‐Zn²⁺ in oxidation and reduction reactions; no reaction occurred upon addition of an oxidant (e.g., cerium(IV) ammonium nitrate (CAN)) to 1 ‐Zn²⁺, whereas 1 ‐Zn²⁺ coordinating two water molecules, (TMC)Fe^III‐(O₂)‐Zn(CF₃SO₃)₂‐(OH₂)₂ [ 1 ‐Zn²⁺‐(OH₂)₂], releases the O₂ unit in the oxidation reaction. In the reduction reactions, 1 ‐Zn²⁺ was converted to its corresponding iron(IV)–oxo species upon addition of a reductant (e.g., a ferrocene derivative), whereas such a reaction occurred at a much slower rate in the case of 1 ‐Zn²⁺‐(OH₂)₂. The present results provide the first biomimetic example showing that water molecules at the active sites of metalloenzymes may participate in tuning the redox properties of metal–oxygen intermediates.     

Photophysical behavior of acridine with amines within the micellar microenvironment of SDS: a time-resolved fluorescence and laser flash photolysis study

The photophysical behavior of acridine (Acr) shows a facilitated water assisted protonation equilibrium between its deprotonated (Acr* ～ 3.4 ns) and protonated forms (AcrH(+)* ～ 33 ns) within a confined environment of sodium dodecyl sulphate (SDS) micelles above the critical micellar concentration of 8 mM. The acidic interface of the micelles is capable of protonating Acr whereas deprotonated Acr is partitioned into the hydrophobic core. The time-resolved-area-normalized-emission spectra confirm the presence of both Acr* and AcrH(+)*, while time-resolved-emission spectra depict time evolution between them. Quenching of AcrH(+)* with triethylamine (TEA) results in a linear Stern-Volmer (S-V) plot, whereas non-linearity arises with N,N-dimethylaniline (DMA). Both steady-state and time-resolved quenching results with TEA are explained on the basis of excited state proton transfer (ESPT), however the reasons behind the quenching of excited Acr with DMA are proposed as ESPT followed by a photoinduced electron transfer. Partitioning of DMA at the interface makes it accessible for both Acr* and AcrH(+)* in hydrophobic and hydrophilic regions of micelles respectively. The rate of electron transfer at the interface is found to be slower compared to that in the hydrophobic core. Characterization of transient intermediates formed during ESPT and PET between Acr and amines by laser-flash photolysis also supports the observation obtained during fluorescence studies. The mode of interactions between Acr and amines inside micelles is controlled by the localization of the proton/electron donors and acceptors in different hydrophobic or hydrophilic regions of such nano-confined environments.     

Optical Generation of mm-Wave Signal Through Optoelectronic Phase-Locked Loop

In this paper, we propose a scheme for the generation of low phase noise tunable mm-wave signal by beating two lightwaves in a photodiode. These two lightwaves are made phase coherent by an optoelectronic phase locked loop.Calculated mm-wave power at a frequency of 60 GHz is found to be -4 dBm.