Second virial coefficients of a polymer of 2-butene-2,3-dibromo-1,4-diol with adipic acid from light scattering measurements in benzene

Light scattering measurements of a polymer of 2-butene-2,3-dibromo-1,4-diol with adipic acid in benzene have been made in the temperature range 283.15–333.15 K. The second virial coefficients and excess thermodynamic functions have been calculated.     

Viscosities and activation energies of flow of mixtures containing 1,2-dibromoethane

The viscosities of the mixtures of 1,2-dibromoethane + cyclohexane, + benzene, +toluene, +o-xylene, +m-xylene, and +p-xylene have been measured at 298.15 and 308.15 K as a function of composition. The viscosity data have been analysed in the light of approaches developed by Hind and Grunberg . Using Eyring kine- matic scheme the viscosity data have been employed to calculate activation energies of flow.     

Simultaneous quantitation of IC87114, roflumilast and its active metabolite roflumilast N‐oxide in plasma by LC‐MS/MS: application for a pharmacokinetic study

A sensitive and reliable high‐performance liquid chromatography–mass spectrometry (LC–MS/MS) was developed and validated for simultaneous quantification IC87114, roflumilast (RFM), and its active metabolite roflumilast N‐oxide (RFN) using tolbutamide as an internal standard. The analytes were extracted by using liquid–liquid extraction and separated on a reverse phase C₁₈ column (50 mm × 3 mm i.d., 4.6 µ) using methanol: 2 mM ammonium acetate buffer, pH 4.0 as mobile phase at a flow rate 1 mL/min in gradient mode. Selective reaction monitoring was performed using the transitions m/z 398.3 > 145.9, 403.1 >186.9, 419.1 > 187.0 and 271.1 > 155.0 to quantify quantification IC87114, RFM, RFN and tolbutamide, respectively. The method was validated over the concentration range of 0.1–60 ng.mL^?1 for RFM and RFN and 6 to 2980 ng.mL^?1 for IC87114. Intra‐ and inter‐day accuracy and precision of validated method were within the acceptable limits of <15% at all concentrations. Coefficients of correlation (r²) for the calibration curves were >0.99 for all analytes. The quantitation method was successfully applied for simultaneous estimation of IC87114, RFM and RFN in a pharmacokinetic drug–drug interaction study in Wistar rats. Copyright © 2012 John Wiley & Sons, Ltd.     

On Noether’s connection

In this article, we show that the curvature of the Noether connection is asymptotic to the Weil–Petersson form. A. Dhillon and T. Foth supported in part by NSERC.     

Working group report: Heavy-ion physics and quark-gluon plasma

This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.     

Current inverse iteration software can fail

Inverse iteration is widley used to compute the eigenvectors of a matrix once accurate eigenvalues are known. We discuss various issues involved in any implementation of inverse iteration for real, symmetric matrices. Current implementations resort to reorthogonalization when eigenvalues agree to more than three digits relative to the norm. Such reorthogonalization can have unexpected consequences. Indeed, as we show in this paper, the implementations in EISPACK and LAPACK may fail. We illustrate with both theoretical and empirical failures. This research was supported, while the author was at the University of California, Berkeley, in part by DARPA Contract No. DAAL03-91-C-0047 through a subcontract with the University of Tennessee, DOE Contract No. DOE-W-31-109-Eng-38 through a subcontract with Argonne National Laboratory, by DOE Grant No. DE-FG03-94ER25219, NSF Grant Nos. ASC-9313958 and CDA-9401156, and DOE Contract DE-AC06-76RLO 1830 through the Environmental Molecular Sciences construction project at Pacific Northwest National Laboraotry (PNNL).     

Multiaxial fatigue life prediction of kiln roller under axis line deflection

This paper investigates the multiaxial fatigue life of the roller in rolling contact with wheels with respect to axis line deflection. The multiaxial fatigue criteria proposed by Wang and Brown, together with the ralnflow counting method and Miner- Palmgren＇s rule, are applied to the cumulative damage estimation and life prediction. As the axis line deflection of overlong kilns generally results in asymmetric load distribution on each roller, the load ratio is introduced to describe the deflection for quantitative stress analyses. The stress analyses are performed within the finite element code ANSYS. The tangential friction stress is calculated in terms ：of the condition of the rolling contact area. By taking one roller as an example, the plotted fatigue life versus load ratio curve discovers how the axis line deflection affects the fatigue life. This study is significant to prevent the fatigue failure of the roller and can provide basis to adjust and optimize the axis line of the rotary kiln.     

Soot formation in a steady, nonpremixed, recirculating flame

An inverted step burner has been designed in which a steady ethylene, recirculating flame is established. The burner was housed within a vertical wind tunnel. Laser extinction was used to determine the soot volume fraction in the recirculation zone. Temperatures were determined by a thermocouple. One-dimensional laser-Doppler velocity (LDV) measurements were obtained with a frequency shift system to measure the flow field in the recirculating flame. All the measurements were obtained for a fixed ethylene flow rate; a low and a high velocity in the approach flow were investigated.

Variation in air velocity changed the structure of the flame. At low flow conditions, the soot loading has two distinct peaks at the lower and upper edge of the flame. At the higher air velocity, the upper part of the flame has a much lower relative soot loading as a result of the shorter residence time. The location of the peak values of the soot also changed with the residence time. The peak temperature was of the order of 1600°C. The soot loading was low in the regions of high temperature and relatively high in regions of low temperatures, reflecting the important role of thermal radiation in these luminous flames. The LDV measurements were used to reveal the nature of the flow field. The local soot loading in the flame increased as the approach flow velocity increased; this result suggests the possibility that soot may continue to grow when it is recirculated to regions of growth in a flame.     

Linear independence of harmonic numbers over the field of algebraic numbers II

The Ramanujan Journal - In a recent article, the authors have studied the arithmetic natures of a certain class of harmonic numbers. The present paper will explore the linear independence of...     

A Convenient One-Pot Synthesis and Nematicidal Activity of Nicotinic Acid Amides

Russian Journal of Organic Chemistry - Seven nicotinic acid amides were synthesized by condensation of nicotinic acid adsorbed on silica gel with different aromatic amines. The synthesized...