Sharp Sobolev Asymptotics for Critical Anisotropic Equations

We investigate blow-up theory and prove sharp Sobolev asymptotics for a general class of anisotropic critical equations in bounded domains of .     

Non-oscillating/Oscillating Shear Layer over a Large Deep Cavity at Low-Subsonic Speeds

The flow over a deep cavity at low subsonic velocity is considered in the present paper. The cavity length-to-depth aspect ratio is L/H = 0.2. Single hot-wire measurements characterized the incident turbulent boundary layer and show the influence of the cavity on the streamwise statistic components just downstream from the cavity. The streamwise mean and fluctuating velocity profiles are affected by the cavity. PIV measurements reveal the presence for ejection-like events responsible of local perturbations of the skewness and the flatness coefficients. Time-resolved PIV technic is also used to characterize phase properties of shear layer oscillating cycle. It is shown that for deep cavity with first Rossiter mode, only one vortical structure is formed at the cavity leading edge. Then, it grows while convecting downstream along the shear layer. A well-defined ejection process begins after the vortex impact near the cavity downstream corner. A cylinder device placed spanwisely near the cavity leading edge eliminates the resonance and highly modifies the behavior of the shear layer flow. In fact, the shear layer could be divided into upper and lower parts with different structure aspects.     

Image encryption based on fractional chaotic pseudo-random number generator and DNA encryption method

Nonlinear Dynamics - Nonlinear dynamic systems and chaotic systems have been quite exhaustively researched in the domain of cryptography. However, the possibility of using fractional chaotic...     

Nanosensing of ATP by fluorescence recovery after surface energy transfer between rhodamine B and curcubit[7]uril-capped gold nanoparticles

The authors describe a method for functionalization of gold nanoparticles (AuNPs) with the supramolecular host molecule, curcubit[7]uril (CB[7]) which can bind rhodamine B (RhB). The fluorescence of RhB is quenched by the AuNPs via surface energy transfer. On addition of ATP, a dimeric RhB-ATP complex is formed and RhB is pushed out of CB[7]. Hence, fluorescence increases by a factor of 8. This fluorescence recovery effect has been utilized to develop a new detection scheme for ATP. The assay, measured at fluorescence excitation and emission wavelengths of 500 nm and 574 nm respectively, works in the 0.5–10 μM concentration range and has a 100 nM detection limit. The method is not interfered by UTP, GTP, CTP, TTP, ascorbic acid and glutathione.

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Graphical abstract Schematic of a method for determination of ATP in the 500 nM to 10 μM concentration range by using fluorescence recovery after surface energy transfer (SET) between rhodamine B (RhB) and gold nanoparticles capped with curcubit[7]uril (CB[7]).

     

Biomimetic oxidation of catechol employing complexes formed in situ with heterocyclic ligands and different copper(II) salts

In the present work, catecholase activity is presented. The complexes were prepared by condensation of the organic ligand pyrazolyl L ₁ –L ₄ and copper(II) ion in situ. The pyrazolyl compounds L ₁ –L ₄ used in this study are: L ₁ is (3,5-dimethyl-pyrazol-1-ylmethyl)-(4-methyl-pyridin-2-yl)-pyrazol-1-ylmethyl-amine; L ₂ is 1-{4-[(3,5-dimethyl-pyrazol-1-ylmethyl)-pyrazol-1-ylmethyl-amino]-phenyl}-ethanone; L ₃ is 1-{4-[(3,5-dimethyl-pyrazol-1-ylmethyl)-[1,2,4]triazol-1-ylmethyl-amino]-phenyl}-ethanone, and L ₄ is 2-[(3,5-dimethyl-pyrazol-1-ylmethyl)-[1,2,4]triazol-1-ylmethyl-amino]-6-methyl-pyrimidin-4-ol, and copper ions salts Cu(II) are (Cu(CH₃COO)₂, CuCl₂, Cu(NO₃)₂ and CuSO₄). In order to determine factors influencing the catecholase activity of these complexes, the effect of ligand nature, ligand concentration, nature of solvent and nature of counter anion has been studied. The best activity of catechol oxidation is given by the combination formed by one equivalent of ligand L ₂ and one equivalent of Cu(CH₃COO)₂ in methanol solvent which is equal to 9.09 µmol L^?1 min^?1. The Michaelis–Menten model is applied for the best combination, to obtain the kinetic parameters, and we proposed the mechanism for oxidation reaction of catecholase.     

Analysis of the Glass-Forming Ability of Fe–Er Alloys,Based on Thermodynamic Modeling

The Fe–Er phase diagram and thermodynamic properties of all its phases are assessed by means of self-consistent analysis. To refine the data on phase equilibria in the Fe–Er system, an investigation is performed in the 10–40 at % range of Er concentrations. The temperature–concentration dependences of the thermodynamic properties of a melt are presented using the model of ideal associated solutions. Thermodynamic parameters of each phase are obtained, and the calculated results are in agreement with available experimental data. The correlation between the thermodynamic properties of liquid Fe–Er alloys and their tendency toward amorphization are studied. It is shown that compositions of amorphous alloys prepared by melt quenching coincide with the ranges of concentration with the predominance of Fe₃Er and FeEr₂ associative groups that have large negative entropies of formation.     

Characterization of different ice habits according to nucleation processes in the electrolyte LiCl · RH2O (6 < R < 9)

The ability to observe different ice nucleation processes in LiCl · RH₂O electrolytes is demonstrated by light scattering experiments. The homogeneous ice nucleation mechanism is analyzed on the basis of Turnbull's theory. This nucleation operates in supercooled water, as deduced from the volumic dependence of the samples on R(5 < R < 9), and is compatible with the definition of the electrolyte as a heterogeneous submicroscopic LiCl·6H₂O medium composed of H₂O and LiCl·6H₂O.     

Stereocontrolled access to isoprostanes via a bicyclo[3.3.0]octene framework

We report a simple and highly stereocontrolled strategy toward the total synthesis of isoprostanes based on a bicyclic alpha,beta-epoxy ketone intermediate 6. Bicyclo[3.3.0]octene scaffold permitted stereodirection of reagents allowing stereoselective epoxidation, diastereoselective ketone reduction, and regioselective epoxide opening otherwise not accessible with a simple cyclopentene framework.     

Electrodeposition of Ge, Si and Si x Ge 1-x from an air- and water-stable ionic liquid

The electrodeposition of Ge, Si and, for the first time, of Si(x)Ge(1-x) from the air- and water-stable ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([Py(1,4)]Tf(2)N) containing GeCl(4) and/or SiCl(4) as precursors is investigated by cyclic voltammetry and high-resolution scanning electron microscopy. GeCl(2) in [Py(1,4)]Tf(2)N is electrochemically prepared in a two-compartment cell to be used as Ge precursor instead of GeCl(4) in order to avoid the chemical attack of Ge(iv) on deposited Ge. Silicon, germanium and Si(x)Ge(1-x) can be deposited reproducibly and easily in this ionic liquid. Interestingly, the Si(x)Ge(1-x) deposit showed a strong colour change (from red to blue) at room temperature during electrodeposition, which is likely to be due to a quantum size effect. The observed colours are indicative of band gaps between at least 1.5 and 3.2 eV. The potential of ionic liquids in Si(x)Ge(1-x) electrodeposition is demonstrated.