Universal Alignment Probabilities and Subset Selection for Ordinal Optimization

We examine in this paper the subset selection procedure in the context of ordinal optimization introduced in Ref. 1. Major concepts including goal softening, selection subset, alignment probability, and ordered performance curve are formally introduced. A two-parameter model is devised to calculate alignment probabilities for a wide range of cases using two different selection rules: blind pick and horse race. Our major result includes the suggestion of quantifiable subset selection sizes which are universally applicable to many simulation and modeling problems, as demonstrated by the examples in this paper.     

The effect of functionalization on structure and electrical conductivity of multi-walled carbon nanotubes

Nanosized powders of Ti-Nb oxide core-shell nanocrystals with atomic ratios of Nb/Ti = 0.11, 0.25, and 0.38 have been prepared by two preparation routes. The first route was co-precipitation, followed by␣annealing, using NbCl₅ as a source of Nb. The second route was coating of pure TiO₂ nanocrystals by Nb-isopropoxide in liquid medium, followed by impregnation of the Nb into the nanoparticles by annealing. Both methods yielded anatase nanocrystals with a Nb-rich shell and a core, which had much lower Nb loadings. The anatase structure solid solution (with Nb incorporated) was stable under annealing up to 760°C. The particle size remained within the nanometric scale (<50 nm) under heat-treatment up to 760°C. It has been shown that the fabricated powders can be redispersed in aqueous media by simple ultrasound treatment, resulting in nanosized dispersions. Using a variety of analytical techniques, including depth profiling of single nanocrystallites by AES combined with sputtering by Ar ions, the mechanism of the core-shell structure creation was studied. It is proposed that the formation of the core-shell structure is governed by solubility limitations in the co-precipitation route and by solubility and diffusion limitations in the coating-incorporation route.     

Spectrophotometric method for the determination of sorbic acid in various food samples with iron(III) and 2-thiobarbituric acid as reagents

A simple, rapid and accurate spectrophotometric method has been developed for the determination of sorbic acid in various food samples based on the oxidation of sorbic acid by iron(III) at 100 degrees C to malonaldehyde, which then reacts with 2-thiobarbituric acid to form a reddish brown product. The optimum experimental conditions for colour development have been assessed. Absorbance measurements were made at 529 nm in the presence of 0.4% m/V citric acid. The calibration graph was linear for 0-6 micrograms ml-1 of sorbic acid with a slope of 0.131 A micrograms-1 ml. The recoveries of sorbic acid at concentrations of 164-557 micrograms ml-1 ranged from 96 to 103%. The relative standard deviations of ten replicate determinations of sorbic acid in a synthetic cream soda sample spiked with 573 micrograms ml-1 of sorbic acid and in an onion juice sample containing 82 micrograms ml-1 of sorbic acid were 1.6 and 1.9%, respectively. Interferences from several common food additives can be minimised by extracting sorbic acid with diethyl ether and then back-extracting the acid with sodium hydrogen carbonate. The method has been applied successfully to the determination of sorbic acid in a wide range of food samples including beverages, cake, cake mate, garlic bread sprinkle, onion juice, oyster flavoured sauce and grenadine syrup.     

The exterior Dirichlet problem for quasi-linear elliptic equations with small boundary data

It is shown that if the order of non-uniformity of a quasi-linear elliptic equation is h,10,2(h–1)/h norm. For 0h1,existence of a bounded solution is guaranteed without any smallness assumption on the given boundary data.More precise information is given for the special case of the minimal surface equation.     

Luminescent biological probes derived from ruthenium(II) estradiol polypyridine complexes

Four luminescent ruthenium(II) polypyridine estradiol complexes [Ru(NwedgeN)2(bpy-estradiol)](PF6)2 (NwedgeN = 2,2'-bipyridine (bpy), 4,7-diphenyl-1,10-phenanthroline (Ph2-phen); bpy-estradiol = 5-(4-(17alpha-ethynylestradiolyl)phenyl)-2,2'-bipyridine (bpy-ph-est), 4-(N-(6-(4-(17alpha-ethynylestradiolyl)benzoylamino)hexyl)aminomethyl)-4'-methyl-2,2'-bipyridine (mbpy-C6-est)) have been designed as new luminescent biological probes. The lipophilicity and photophysical and electrochemical properties of these complexes have been investigated. Upon photoexcitation, all the complexes exhibited intense and long-lived triplet metal-to-ligand charge-transfer (3MLCT) (dpi(Ru) --> pi*(diimine)) emission in fluid solutions at 298 K and in low-temperature glass. The binding of the complexes to estrogen receptor-alpha (ERalpha) has been studied by emission titrations. The Ph2-phen complexes showed emission enhancement and increased lifetimes upon binding to the protein. Additionally, the cytotoxicity of the complexes toward the HeLa cell line has been examined by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay and the IC50 values ranged from 83.1 to 166.6 microM (cisplatin showed an IC50 value of 34.3 microM under the same experimental conditions). Furthermore, the cellular uptake of the complexes has been investigated by flow cytometry and laser-scanning confocal microscopy.     

Room-Temperature Guerbet Reaction with Unprecedented Catalytic Efficiency and Enantioselectivity

We report herein an unprecedented highly efficient Guerbet-type reaction at room temperature (catalytic TON up to >6000). This β-alkylation of secondary methyl carbinols with primary alcohols has significant advantage of delivering higher-order secondary alcohols in an economical, redox-neutral fashion. In addition, the first enantioselective Guerbet reaction has also been achieved using a commercially available chiral ruthenium complex to deliver secondary alcohols with moderate yield and up to 92 % ee. In both reactions, the use of a traceless ketone promoter proved to be beneficial for the catalytic efficiency.     

Improving electroless Cu via filling with optimized Pd activation

To improve the via fill capability of electroless (EL) Cu, we explored the influence of the Pd activation process prior to EL Cu deposition. We found that EL Cu roughness is closely related to the Pd nuclei size range and density, which are functions of Pd activation time. With activation time, Pd deposition goes through the sequential stages of growth, secondary nucleation, and ripening. The smoothest EL Cu film can be achieved with a Pd nucleation time that corresponds to the beginning of the ripening stage. A Pd activation process that leads to the smoothest EL Cu deposit also yields the most conformal via filling.     

The World of Synthetic Polymers.An Industrial Perspective

Synthetic polymers have become the building block in almost every aspects of our daily life. Billions of pounds of polymers are produced each year and the demand is continuously growing both in terms of volume and advanced performance. The general property of a class of polymers is often bounded by the synthetic process that produces the polymer. For example,polyolefins, are non-polar polymers due to the poor tolerance of transition metal catalysts toward polar monomers. Conversely, latices are polar polymers, since the emulsion polymerization process limits the use of non-polar monomers which have low solubility in water. It is highly desirable to be able to design polymer systems with optimum polarity balance to meet the application demand while staying within the industrial manufacturing constraints.An overview of industrial polymerization methods will be followed by a presentation on the recent development of a new emulsion polymerization technology. The technology involves the use of Cyclodextrin, acting as "Phase Transport Catalyst", facilitating the diffusion of very hydrophobic and water insoluble monomers through the aqueous medium. A new class of latex polymers and their attributes will be discussed.     

Thermal Raman shift of the C60 tangentialA g mode

Fullerence C₆₀ exhibits a continuous and reversibleA _g (2) mode softening from 1469 to 1459 cm^–1, which is linear with laser power up to 21.9 kW/cm² for C₆₀ crystals under vacuum. Model calculations taking into account the temperature distribution that is induced by the Gaussian intensity profile of the laser beam reproduce the measured frequency shifts. A thermal conductivity of microcrystalline fullerene of 0.27(±0.03) W/mK is derived from this numerical analysis.