Asymptotic behavior of integrals connected with spectral functions for hypoelliptic operators

In the first part of this paper are considered real polynomialsP(ζ), ζ∈R ⁿ, complete and nondegenerate in the sense that there is a set of (even) multi-indices α ^j ,j=1,...,N, such that, for |ζ|>K, ζ real,

$$cP(\xi ) \leqslant \sum {\xi ^{\alpha j} } \leqslant CP(\xi ).$$     

POLYMERIC SURFACTANTS BASED ON OLEIC ACID IV. Lamellar Liquid Crystal Polymerization of Sodium Oleate/Oleic Acid/Aliphatic Diene/Water System

The lamellar liquid crystalline phase in the system consisting of sodium oleate (NaOL), oleic acid (OLA), and water was determined. The interlayer spacing (d) of the lamellar liquid crystal was measured through small angle X-ray diffraction, which indicated that oleic acid molecules were solubilized between the end methyl groups at low concentrations, and then were located within the hydrocarbon chain layer with further increase of its concentration. Cross-linking agents were added to the system, which were found being located partly in between the end methyl groups and partly within the hydrocarbon chain layers. The liquid crystal phase of NaOL/OLA/H₂O system with the cross-linking agent was polymerized at 60 °C, which turned out to be a mixture of liquid crystals and solids. Interlayer spacing decreased by about 10 Å, indicating a disruption of the ordered structure by the polymerization. The polymerization took place not only within the hydrocarbon layer, but also in between the layers separated by the end methyl groups. The resulting polymer lowered the surface tension of water to below 30 mN/m, with a critical micellization concentration of about O.25g/L.     

Vapor Pressures of Phenethyl Alcohol in the System Water-Phenethyl Alcohol and the Triblock Copolymer EO4.5PO59 EO4.5

ABSTRACT

The phase diagram of water, phenethyl alcohol (PEA) and the triblock copolymer EO_4.5PO₅₉EO_4.5, (EO = ethylene oxide, PO = propylene oxide), L101, was determined and the vapor pressures of PEA were measured for different phases.

The phase diagram was almost identical to the corresponding one with a simple nonionic surfactant, Laureth 4, (?C₁₂EO₄), but the PEA vapor pressure variation with mole fraction was significantly different reflecting the strong molecular interaction between PEA and the polymer. This distinction was mainly due to difference in molecular size; vapor pressure plots against weight fraction gave curves with only moderate variance.

The results were used to discuss the variation in the PEA vapor pressure with time after application of a vesicular solution of PEA stabilized either by L101 or Laureth 4. The moderate differences in vapor pressures had a significant influence on the estimated curves of PEA pressure versus time.     

MICROEMULSIONS AND LIQUID CRYSTALS WITH WHITE OIL

Phase maps were determined in the system water, sodium dodocyl sulfate, pentanol and a commercial mineral oil (Drakeol® 7) and the dimensions in the lamellar liquid crystal were determined using low angle x-ray diffraction. The mineral oil gave a strong reduction in the water-in-oil microemulsion region solubilization capacity for water when combined with the cosurfactant in a 1/1 weight ratio. For less oil/cosurfactant ratios a large oil-in-water microemulsion region was observed

The mineral oil added to the liquid crystal in the system strongly reduced the water penetration into the hydrocarbon chain region and enhanced the disorder of the hydrocarbon chains in the structure.     

Phase Equilibria of Methoxydimethyloctylsilane,Tetramethyldioctyldisiloxane in Organic Solvents

Abstract The phase diagrams and partial solubility parameters for methoxydimethyloctyl silane (MDOS), tetramethyl dioctyl disiloxane (TDDS), and several organic components were determined. The solubility limits were established by quantitative analysis and compared to the refractive index of known single phase mixtures. The partial solubility parameters were used to provide a qualitative analysis of the phase equilibria. The results showed the phase equilibria depended on the polarity and hydrogen bonding characteristics of the solvents. The solubility of TDDS was reduced with increasing polarity/hydrogen bond character of the amphiphiles solvents.     

Influence of pitch, loudness, and timbre on the perception of instrument dynamics

The effect of variations in pitch, loudness, and timbre on the perception of the dynamics of isolated instrumental tones is investigated. A full factorial design was used in a listening experiment. The subjects were asked to indicate the perceived dynamics of each stimulus on a scale from pianissimo to fortissimo. Statistical analysis showed that for the instruments included (i.e., clarinet, flute, piano, trumpet, and violin) timbre and loudness had equally large effects, while pitch was relevant mostly for the first three. The results confirmed our hypothesis that loudness alone is not a reliable estimate of the dynamics of musical tones.     

Visibility in ghost imaging with classical partially polarized electromagnetic beams

We consider classical second-order ghost imaging with uniformly partially polarized electromagnetic beams and examine the effect of the degree of polarization of the incident light on the visibility of the image. Closed-form expressions for two previously proposed definitions of visibility are derived. Both results are physically similar and show that the visibility increases with the degree of polarization. Hence, a polarized beam is superior to an unpolarized one to obtain a high-visibility ghost image. Some related issues in recent literature are also addressed.     

Quality control in integrated human exposure monitoring of lead and cadmium

Summary The Human Exposure Assessment Location, HEAL, Project is implemented by WHO/UNEP in close collaboration with national agencies in different countries. In a first phase methods for exposure monitoring of Pb, Cd, DDT, HCB and NO₂ will be tested in China, Japan, Sweden, USA and Yugoslavia, possibly also Brazil and India. The Pb/Cd study, which involves measurements of lead and cadmium in blood, duplicate diets, feces and inhaled air, collected by a group of non-smoking women in each participating country, is coordinated by a Technical Coordinating Centre (TCC) in Sweden. In order to assure accuracy and comparability of data an extensive quality assurance programme has been developed. Quality control (QC) samples for lead and cadmium in blood, feces, air filters, dust and diets have been prepared. Sets of 4–6 External Quality Control (EQC) samples, the metal concentrations of which are unknown to the laboratories, and 1–2 Internal Quality Control (IQC) samples with stated Pb/Cd-levels, have been distributed. The analytical performance evaluation is based on linear regression analysis of reported results (y) versus reference values (x). Criteria for how much the regression line may deviate (Maximum Accepted Deviation, MAD) from the ideal line (y=x) have been developed. A power of 90% is employed, which means that the actual acceptance interval for the regression line is slightly narrower than the MAD-interval. This procedure gives an estimate of the maximum systematic errors involved in the analysis. The MAD criteria for the evaluation of QC results are based on the data quality requirements as well as the feasibility of the analytical techniques.The results of the first QC rounds show that good analytical performance on one QC sample is no guarantee for good results at higher or lower concentrations or good results with other types of samples. Furthermore, analytical performance may vary with time.

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Qualitätskontrolle bei der integrierten Überwachung der menschlichen Belastung mit Blei und Cadmium