Temperature imaging of turbulent dilute spray flames using two-line atomic fluorescence

To study the behavior of thixotropic yield stress fluids, information at the local scale is required in order to determine precisely the yield point value, and the shear rate and stresses can be obtained all over the flow. This study focuses on the flow in a large shear cell of a Laponite suspension. In order to be able to construct a local rheogram for this suspension, two different methods issued from fluid mechanics and solid mechanics are used. Local velocities are determined with a PIV technique, and local stresses are determined with the photoelasticimetry technique.     

Isomeric yield ratios in the photoproduction of 52m,gMn from natural iron using 50-, 60-, 70-MeV, and 2.5-GeV bremsstrahlung

The isomeric yield ratios for the ^natFe(γ,xn1p)^52m,gMn reactions have been measured by the activation and the γ-ray spectroscopic methods at 50-, 60-, 70-MeV, and 2.5-GeV bremsstrahlung energies. The high purity natural iron foils in disc shape were irradiated with uncollimated bremsstrahlung beams of the Pohang Accelerator Laboratory. The induced activities in the irradiated foils were measured by the high-resolution γ-ray spectrometry with a calibrated high-purity Germanium (HPGe) detector. In order to improve the accuracy of the experimental results the necessary corrections were made in the gamma activity measurements and data analysis. The obtained isomeric yield ratios for the ^natFe(γ,xn1p)^52m,gMn reactions at 50-, 60-, 70-MeV, and 2.5-GeV bremsstrahlung energies are 0.27 ± 0.03, 0.33 ± 0.04, 0.34 ± 0.04, and 1.25 ± 0.15, respectively. The present results at 50-, 60-MeV, and 2.5-GeV bremsstrahlung energies are the first measurements. We found that the isomeric yield ratio of the ^natFe(γ,xn1p)^52m,gMn reaction depends on the incident bremsstrahlung energy and the mass difference between the product and the target nucleus when we compared the present results with other experimental data at different energies.     

Some Weighted Energy Classes of Plurisubharmonic Functions

In this paper we study relations between the weighted energy class E_c\mathcal{E}_{\chi} introduced by S. Benelkourchi, V. Guedj and A. Zeriahi recently with Cegrell’s classes E\mathcal{E} and N\mathcal{N}. Next we establish a generalized comparison principle for the operator M _χ . As an application, we prove a version of existence of solutions of Monge–Ampère type equations in the class E_c(H,W)\mathcal{E}_{\chi}(H,\Omega).     

Measurement of isomeric yield ratios for the <Superscript>110</Superscript>Pd(γ,n)<Superscript>109m,g</Superscript>Pd reaction

We measured the isomeric yield ratios for the ¹¹⁰Pd(γ,n)^109m,gPd reaction by the activation method with the bremsstrahlung endpoint energies of 50-, 55-, 60-, 65-, and 70-MeV generated from an electron linear accelerator of Pohang accelerator laboratory. The induced γ-activities of the irradiated palladium foils were measured by a coaxial high purity germanium detector coupled to a PC-based multi-channel analyzer. The necessary corrections were made to improve the accuracy of the γ-activity measurements. The present experimental results measured with bremsstrahlung endpoint energies of 50-, 55-, 60-, 65-, and 70-MeV are 0.108 ± 0.007; 0.118 ± 0.008; 0.118 ± 0.007; 0.120 ± 0.008; 0.119 ± 0.008, respectively. The obtained results are compared with those existing in literature.     

Steric effects and competitive intra‐ and intermolecular host‐guest complexation between beta‐cyclodextrin and adamantyl substituted poly(acrylate)s in water: A 1H NMR,rheological and preparative study

A ¹H NMR and rheological study of host‐guest complexation interactions between three β‐cyclodextrin and three adamantyl substituted poly(acrylate)s, and also between them and adamantan‐1‐carboxylate and native β‐cyclodextrin, respectively, is reported. A close correllation between molecular level interactions and macroscopic characteristics of polymer networks in aqueous solution exists. It is found that intra‐ and intermolecular host‐guest complexation between the host β‐cyclodextrin and guest adamantyl substituents and the length of the aliphatic tether between them and the poly(acrylate) backbone have important roles. Dominantly, steric effects and competitive intra‐ and intermolecular host‐guest complexation are found to control poly(acrylate) isomeric interstrand linkage in polymer network formation. The preparations of five new 3% randomly substituted poly(acrylate)s are reported. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1818–1825, 2010     

On exponential stability of nonlinear differential systems with time-varying delay

General nonlinear differential systems with time-varying delays are considered. Several explicit criteria for exponential stability are presented. An example is given to illustrate the obtained results. To the best of our knowledge, the results of this note are new.     

Aromatic Homologation by Non‐Chelate‐Assisted RhIII‐Catalyzed C?H Functionalization of Arenes with Alkynes

Larger condensed arenes are of interest owing to their electro‐ and photochemical properties. An efficient synthesis is the catalyzed aromatic annulation of a smaller arene with two alkyne molecules. Besides difunctionalized starting materials, directed C H functionalization can be used for such aromatic homologation. However, thus far the requirement of either pre‐functionalized substrates or suitable directing groups were limiting this approach. Herein, we describe a rhodium(III)‐catalyzed method allowing the use of completely unbiased arenes and internal alkynes. The reaction works best with copper(II) 2‐ethylhexanoate and decabromodiphenyl ether as the oxidant combination. This aromatic annulation tolerates a variety of functional groups and delivers homologated condensed arenes. Aside from simple benzenes, naphthalenes and higher condensed arenes provide access to highly substituted and highly soluble acenes structures having important electronic and photophysical properties.     

Determination of the orientational ordering of 4′-cyanophenyl-4-alkylbenzoates by 13C NMR

Abstract

The orientational ordering of three 4′-cyanophenyl-4-alkylbenzoates (with number of carbons in the alkyl chain, n = 6,7 and 8; hereafter abbreviated as n-CPBs) has been investigated by ¹³C NMR. The order parameters of different molecular segments in the nematic phase of the n-CPBs were determined by the two-dimensional technique of separated local field (SLF) spectroscopy combined with off-magic-axis, variable-angle spinning (VAS) of the sample. The carbon-13 chemical shifts for each carbon nucleus in these compounds were determined by slowly spinning the sample parallel to the applied magnetic field. The order parameters obtained from SLF/VAS studies are linearly related to the corresponding anisotropic carbon-13 chemical shifts. These results provide a convenient way to obtain the order parameters for other homologous members of this liquid crystal series by direct measurement of only their carbon-13 chemical shifts in conjunction with the observed linear relationship between order parameters and chemical shifts.     

Regularity dimension of sequences and its application to phylogenetic tree reconstruction

The concept of dimension is a central development of chaos theory for studying nonlinear dynamical systems. Different types of dimensions have been derived to interpret different geometrical or physical observations. Approximate entropy and its modified methods have been introduced for studying regularity and complexity of time-series data in physiology and biology. Here, the concept of power laws and entropy measure are adopted to develop the regularity dimension of sequences to model a mathematical relationship between the frequency with which information about signal regularity changes in various scales. The proposed regularity dimension is applied to reconstruct phylogenetic trees using mitochondrial DNA (mtDNA) sequences for the family Hominidae, which can be validated according to the hypothesized evolutionary relationships between organisms.