Pronounced Fluctuations of Target Fragments in Forward Hemisphere Only in Ultra Relativistic Nuclear Collision

Dynamical fluctuation of target evaporated black particles is investigated in both forward and backward hemispheres within the framework of multi-dimensional factorial moment methodology using the brilliant concept of the Hurst exponent. We analyse the black particles emitted in ^32S-AgBr interactions at 200AGeV and it is evident that the dynamical fluctuation in the backward hemisphere is self-affine. In the forward hemisphere, dynamical fluctuation is self-similar but not self-affine. However, study indicates that the fluctuation in the forward hemisphere is more pronounced than that in backward hemisphere.     

Evidence of Strong Pion Fluctuation in Jet-Like Events in ^32S-AgBr Interactions

We presents the analysis of ring-like and jet-like events in terms of Scaled Factorial Moments （SFMs） in one dimensional space up to the sixth order of moments for ^32S-AgBr interactions at 200 AGeV energy. The study reveals a power law growth of SFMs with decreasing bin width of the azimuthal distribution in the ^32S- AgBr data at 200 AGeV in both the cases. It is seen that strong intermittent pattern is revealed only in jet-like events.     

Exterior Stokes flows with stick-slip boundary conditions

Steady two-dimensional creeping flows induced by line singularities in the presence of an infinitely long circular cylinder with stick-slip boundary conditions are examined. The singularities considered here include a rotlet, a potential source and a stokeslet located outside a cylinder and lying in a plane containing the cylinder axis. The general exterior boundary value problem is formulated and solved in terms of a stream function by making use of the Fourier expansion method. The solutions for various singularity driven flows in the presence of a cylinder are derived from the general results. The stream function representation of the solutions involves a definite integral whose evaluation depends on a non-dimensional slip parameter l₁\lambda_1. For extremal values, l₁ = 0\lambda_1 = 0 and l₁ = 1\lambda_1 = 1, of the slip parameter our results reduce to solutions of boundary value problems with stick (no-slip) and perfect slip conditions, respectively.¶The slip parameter influences the flow patterns significantly. The plots of streamlines in each case show interesting flow patterns. In particular, in the case of a single rotlet/stokeslet (with axis along y-direction) flows, eddies are observed for various values of l₁\lambda_1. The flow fields for a pair of singularities located on either side of the cylinder are also presented. In these flows, eddies of different sizes and shapes exist for various values of l₁\lambda_1 and the singularity locations. Plots of the fluid velocity on the surface show locations of the stagnation points on the surface of the cylinder and their dependencies on l₁\lambda_1 and singularity locations.     

On some testing problems for sparse contingency tables

A class of test statistics are proposed for sparse tables with ordered categories. It is shown that for different testing situations these test statistics asymptotically more powerful tests than Pearson's chi-square.     

Isomeric Diruthenium Complexes Bridged by Deprotonated Indigo in cis and trans Configuration

The doubly deprotonated form L^2? of indigo=H₂L can bind two [Ru(acac)₂] complex fragments in the cis ( 1 ) and trans configuration ( 2 ), as evidenced from crystal structure analysis. While the latter type of N,O; N ^’ ,O ^’ coordination has been observed earlier, for example, with [Ru(bpy)₂]²⁺, leading to two equivalent six‐membered ring chelates, the cis arrangement in 1 is observed here for the first time in a dinuclear complex, producing one five‐membered ring chelate with N,N ^’ coordination and one seven‐membered chelate with O,O ^’ coordination. The different structures of the isomers result in differing electrochemical and spectroelectrochemical (EPR, UV‐Vis‐NIR) responses for various accessible charge states 1 ⁿ and 2 ⁿ, n=–, 0, +, 2+. The associated electronic structures were analyzed by DFT (structures, spin density) and TD‐DFT calculations (electronic transitions), revealing mainly metal‐based reduction but largely indigo ligand‐based oxidation of both neutral precursors.     

Light‐induced degradation and regeneration of multicrystalline silicon Al‐BSF and PERC solar cells

Light‐induced degradation (LID) is a well‐known problem faced by p‐type Czochralski (Cz) monocrystalline silicon (mono‐Si) wafer solar cells. In mono‐Si material, the physical mechanism has been traced to the formation of recombination active boron‐oxygen (B–O) complexes, which can be permanently deactivated through a regeneration process. In recent years, LID has also been identified to be a significant problem for multicrystalline silicon (multi‐Si) wafer solar cells, but the exact physical mechanism is still unknown. In this work, we study the effect of LID in two different solar cell structures, aluminium back‐surface‐field (Al‐BSF) and aluminium local back‐surface‐field (Al‐LBSF or PERC (passivated emitter and rear cell)) multi‐Si solar cells. The large‐area (156 mm × 156 mm) multi‐Si solar cells are light soaked under constant 1‐sun illumination at elevated temperatures of 90 °C. Our study shows that, in general, PERC multi‐Si solar cells degrade faster and to a greater extent than Al‐BSF multi‐Si solar cells. The total degradation and regeneration can occur within ～320 hours for PERC cells and within ～200 hours for Al‐BSF cells, which is much faster than the timescales previously reported for PERC cells. An important finding of this work is that Al‐BSF solar cells can also achieve almost complete regeneration, which has not been reported before. The maximum degradation in Al‐BSF cells is shown to reduce from 2% (relative) to an average of 1.5% (relative) with heavier phosphorus diffusion.     

Interaction and incorporation of ovalbumin with stearic acid monolayer: Langmuir-Blodgett film formation and deposition

In this communication, the surface activity of the ovalbumin (OVA) at the air/water interface was studied to establish the nature of the interaction with the stearic acid (SA) monolayer, based on Langmuir–Blodgett (LB) technique. The interaction was monitored by studying the time (t) variation of surface pressure (π) at constant area (A). The growth of π with time indicates a positive association between the SA and the OVA molecules. The surface compressibility analysis has been performed to specify the phase transition of OVA–SA mixed monolayer. Incorporation/association of OVA within the SA monolayer led to noteworthy changes in surface compressibility and was surface pressure as well as protein concentration dependent. Both the hydrophobic and the Vander wall type interactions are found to be responsible for the association. The quenching of tyrosine band in tryptophan excitation spectrum is observed in steady-state fluorescence spectroscopy. This suggests that the tyrosine is the probable binding site with SA. Due to incorporation of SA, the energy transfer from tyrosine to tryptophan is hindered. At higher pressure, OVA tend to squeeze out from the SA monolayer. The high-resolution field emission scanning electron microscope (FE-SEM) image confirms this observation. Aggregated protein structure observed at high pressure indicates unfolding of protein.     

Interaction of ovalbumin with phospholipids Langmuir-Blodgett film

Interaction of native ovalbumin (OVA) with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) Langmuir-Blodgett monolayer has been studied at the air-water interface. A compressibility study shows the positive association with DPPC. Adsorption kinetics shows that the protein adsorption is a one-step process and the amount of protein adsorbed depends on the concentration of protein at the water subphase. Incorporation of protein into the DPPC layer is surface-pressure dependent. The compressibility study indicates that the DPPC-OVA interaction is hydrophobic in nature and structural reorganization is eminent to adjust the hydrophobic mismatch between DPPC acyl chains and OVA hydrophobic moieties. At higher pressure, OVA tends to squeeze out from the DPPC monolayer. A nanometer scale FE-SEM image confirms this observation. Globular aggregates of protein of dimension 60-80 nm were observed in DPPC-OVA supported film. Steady-state fluorescence spectroscopy suggests that the tryptophan residues of OVA are main emitting species. The blue shift of tryptophan fluorescence in supported film may be due to the tryptophan molecule of protein exposed to the hydrophobic air phase.