Long range ordering in self-assembled Ni arrays on patterned Si

We have succeeded in aligning self-assembled structures by using a lithographically defined stripe. The 140 nm wide by 100 nm high SiO₂ strip is shown to guide the assembly of 500 nm latex spheres so that spheres are aligned along the strip and are in registration on either side of the strip. This method can be used to increase long-range ordering in magnetic storage systems without compromising the density. Inverse sphere Ni arrays were made by electrodeposition through the latex template. We also show that the hexagonal symmetry of the resulting inverse sphere Ni arrays can be simulated using the approach presented below.     

The Stereochemistry of the Reaction of α-Silyl Lithium Reagents with Cyclic Tert-butyldimethylsilyl Acyloins

The reactions of the tert-butyldimethylsilylated acyloins of five-, six- and seven-membered rings with the lithium reagents of benzyltrimethylsilane, thiophenoxymethyltrimethylsilane and tri-methylsilyl acetonitrile were studied. These reactions favor formation of the substituted (Z) exo methylidene silyl ethers in moderate yields.     

A kinetic study of the reactions of sulfate and dihydrogen phosphate radicals with epicatechin,epicatechingallate, and epigalocatechingallate

The bimolecular rate constants for the reactions of sulfate radicals with epicatechin (EC), epicatechingallate (ECG), and epigallocatechingallate (EGCG) were found to be (1.46 ± 0.06) × 10⁹, (1.20 ± 0.08) × 10⁹, and (1.04 ± 0.07) × 10⁹, respectively. The activation energy [E_A = 9 ± 3 kJ mol^?1] and preexponential factor [A = (4.8 ± 0.6) × 10¹⁰] for the reaction of EC with the sulfate radical were measured in the temperature range 288–303 K. The phenoxyl radicals of EC (λ_max = 310 nm) were obtained both by the reaction of this flavonoid with the sulfate radicals and by photoionization. The measured bimolecular rate constants for the reactions of the dihydrogen phosphate radicals with EC, ECG, and EGCG were (7.8 ± 0.9) × 10⁸, (8.5 ± 0.4) × 10⁸, and (6.8 ± 0.4) × 10⁸, respectively. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 391–396, 2010     

Revision of a theoretical expression for gas-liquid chromatographic retention.

In this communication, we revise some aspects of the [ideal gas/Van der Waals fluid] partition, derived in an earlier publication. The general character of the conclusions concerning the dependence of the partial molar free energy of solution, deltaGs(n), on the chain length, n, of linear solute molecules is shown through the relationship with more general partition formulations. Simultaneously, the correction of an error in the expression of the retention time dependence on the phase ratio of the chromatographic column, beta, is carried out. The misleading source of this error was redundant accounting in the solute translational contribution to deltaGs(n).     

Gas chromatographic determination of gallopamil and norgallopamil in human plasma

A highly sensitive gas chromatographic assay is described for the simultaneous determination of gallopamil, a calcium channel blocking agent, and its major metabolite, norgallopamil. A multi-step extraction procedure is employed followed by on-column capillary gas chromatographic analysis using nitrogen-selective detection. Acetylation of norgallopamil is performed to enable accurate quantification of the metabolite. Linearity was achieved over the range 1-50 ng/ml for both analytes. Assay specificity, precision and accuracy were investigated.     

Adaptive Martingale Approximations

H-systems are those orthonormal systems which allow computation of conditional expectations via a Fourier expansion. These systems provide natural approximations to continuous stochastic processes and we indicate how they could be used to perform lossy compression on a set of given signals. More specifically, we show how to construct, for a given random variable, an adaptive martingale approximation by means of generalized Haar functions. We also indicate how the construction can be extended to a given random vector. A generalized multiresolution analysis algorithm is also described and numerical examples are provided.