Statistical properties of turbulence: An overview

We present an introductory overview of several challenging problems in the statistical characterization of turbulence. We provide examples from fluid turbulence in three and two dimensions, from the turbulent advection of passive scalars, turbulence in the one-dimensional Burgers equation, and fluid turbulence in the presence of polymer additives.     

Dioxygen reactivity of meso -hydroxylated hemes: Intermediates in heme degradation process catalyzed by heme oxygenase

Heme oxygenase (HO) is the only enzyme in mammals known to catalyse the physiological degradation of unwanted heme into biliverdin, Fe ion and CO. The process involves introduction of the hydroxyl group at one of itsmeso-positions as the first fundamental step of the heme cleavage process. It was also found thatmeso-amino heme undergoes similar ring-cleavage process while reacting with dioxygen in presence of pyridine as an axial ligand. The present paper briefly reviews the reactions of modelmeso-hydroxylated heme and its analogues with dioxygen, and their relevance in the heme degradation process.     

Preparation of crosslinked microspheres and porous solids from hydrocarbon solutions: A new variation of precipitation polymerization chemistry

A new variation of precipitation polymerization is described wherein C H bond addition to a triallyl monomer contributes to molecular weight growth, thereby incorporating a significant amount of saturated hydrocarbon into the solid phase. The extent of monomer oligomerization relative to hydrocarbon addition is shown to increase with the concentration of allyl benzoate in cyclooctane. An extension to the trifunctional monomer, triallyl trimesate, results in phase separation of hydrocarbon‐monomer adducts to give a dispersed phase whose continued reactivity leads to crosslinked microspheres. The relationships between reaction conditions and solid‐phase composition and morphology are discussed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6561–6570, 2009     

Characterization of sol-gel-prepared nanoferrites

Spinel Co_1−xMn_xFe₂O₄ nanoparticles were prepared by the sol-gel combustion technique. X-ray diffraction (XRD), atomic force microscopy (AFM) and vibration sample magnetometer (VSM) studies have been carried out in order to understand the temperature dependence of their properties. It is observed that the high concentration of Mn²⁺ substituted into CoFe₂O₄ tends to reduce the particle size. Furthermore, the influence of Mn on the magnetic and thermal characteristics of Co_1−xMn_xFe₂O₄ nanoparticles has been investigated in detail.     

Likelihood-based Inference for the Ratios of Regression Coefficients in Linear Models

We consider the standard linear multiple regression model in which the parameter of interest is the ratio of two regression coefficients. Our setup includes a broad range of applications. We show that the 1− α confidence interval for the interest parameter based on the profile, conditional profile, modified profile or adjusted profile likelihood can potentially become the entire real line, while appropriately chosen integrated likelihoods do not suffer from this drawback. We further explore the asymptotic length of confidence intervals in order to compare integrated likelihood-based proposals. The analysis is facilitated by an orthogonal parameterization.     

A highly efficient heterogeneous montmorillonite K‐10‐supported palladium catalyst for Suzuki–Miyaura cross‐coupling reaction in aqueous medium

A heterogeneous montmorillonite K‐10‐supported palladium triphenylphosphine catalyst is reported for the Suzuki–Miyaura cross‐coupling reaction at room temperature. A library of electronically diverse aryl bromides and arylboronic acids underwent the cross‐coupling reaction at very good rates in aqueous solvent. The reusability of the catalyst was also examined and it was found to be effective up to three catalytic cycles. Copyright © 2014 John Wiley & Sons, Ltd.     

Stereochemical investigation of conjugate additions of carbon- and heteronucleophiles to ring-substituted nitrosocyclohexenes

Intermolecular Michael-type conjugate additions of some in situ-generated ring-substituted nitrosocyclohexenes with both carbon- and heteronucleophiles have been found to be highly stereoselective, leading predominantly (or exclusively) to products resulting from axial attack on a half-chair conformation of the nitrosoalkene substrate.     

Analysis of anisotropy of numerical wave solutions by high accuracy finite difference methods

Fourier analysis is used to quantitatively assess the resolution, and in particular the isotropy of wave solution using finite difference spatial discretization schemes along with fourth order Runge–Kutta temporal scheme. Aspect ratio of the grid in two-dimension, along with the angle of wave propagation are the parameters varied to qualitatively and quantitatively assess the anisotropy of the solutions for (a) a skewed one-dimensional wave convecting in two-dimensions following the standard convection equation and (b) a wave propagating following the two-dimensional linearized rotating shallow water equations. Results show the effect of changing the aspect ratio and the propagation angle on the directional nature of the solution as obtained by different methods for the above non-dispersive and dispersive wave system.     

Speciation and detection of arsenic in aqueous samples: A review of recent progress in non-atomic spectrometric methods

Inorganic arsenic (As) displays extreme toxicity and is a class A human carcinogen. It is of interest to both analytical chemists and environmental scientists. Facile and sensitive determination of As and knowledge of the speciation of forms of As in aqueous samples are vitally important. Nearly every nation has relevant official regulations on permissible limits of drinking water As content. The size of the literature on As is therefore formidable. The heart of this review consists of two tables: one is a compilation of principal official documents and major review articles, including the toxicology and chemistry of As. This includes comprehensive official compendia on As speciation, sample treatment, recommended procedures for the determination of As in specific sample matrices with specific analytical instrument(s), procedures for multi-element (including As) speciation and analysis, and prior comprehensive reviews on arsenic analysis. The second table focuses on the recent literature (2005–2013, the coverage for 2013 is incomplete) on As measurement in aqueous matrices. Recent As speciation and analysis methods based on spectrometric and electrochemical methods, inductively coupled plasma-mass spectrometry, neutron activation analysis and biosensors are summarized. We have deliberately excluded atomic optical spectrometric techniques (atomic absorption, atomic fluorescence, inductively coupled plasma-optical emission spectrometry) not because they are not important (in fact the majority of arsenic determinations are possibly carried out by one of these techniques) but because these methods are sufficiently mature and little meaningful innovation has been made beyond what is in the officially prescribed compendia (which are included) and recent reviews are available.