Soap‐free emulsion copolymerization of perfluoroalkyl acrylates in the presence of a reactive surfactant

Soap‐free emulsion copolymerization of perfluoroalkyl acrylate (FA)/methyl methacrylate (MMA)/n‐butyl acrylate (n‐BA) was carried out in the presence of sodium 2‐acrylamide‐2‐methyl propanesulfonate (AMPSNa) as a reactive surfactant and potassium persulfate (KPS) as an initiator. An analysis of the effects of concentration of AMPSNa, KPS, FA as well as polymerization temperature on the kinetic features (rate of polymerization) and colloidal characteristics (mean particle diameter, particle disperse index, particle numbers, and surface charge density) was followed. NMR, FTIR, AFM, and fluorine‐selective electrode analysis were used to characterize the composition and morphology of the FA copolymers. Both AFM analysis and contact angle measurements strongly implied that the fluorinated segments migrated to the outmost surface and created films with lower surface energy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2438–2444, 2007     

Effects of estrogen-induced hyperlipidemia on the erythrocyte membrane in chicks

The effects of estrogen-induced hyperlipidemia on plasma lipid peroxidation, fatty acid composition and osmotic fragility of erythrocytes in chickens were studied. Young male chickens implanted with estrogen for three wk developed a marked hyperlipidemia. Plasma levels of triglyceride, cholesterol and phospholipid were elevated 68-, four- and 24-fold, respectively, over controls. There was also a two-fold increase in plasma lipid peroxidation measured by the thiobarbituric acid test. Vitamin E supplement (1,000 IU/kg diet) reduced the plasma lipid peroxidation to the control level, but had no effect on the plasma lipid content. Estrogen-induced hyperlipidemia resulted in changes in the fatty acid composition of membrane lipids of erythrocytes. The major changes were an increase in oleic acid from 10.0% to 14.2% and a decrease in linoleic acid from 31.3% to 26.0%. The erytrocytes with an altered membrane fatty acid composition were found to have an increased osmotic fragility. It was apparent that there was a direct correlation between the oleic acid content and the osmotic fragility of erythrocytes.     

Effect of Antimony Addition on Electrical and Optical Properties of Tin Oxide Film

Antimony-doped tin oxide films were prepared on Corning glass substrate by chemical vapor deposition from a gas mixture of SnCl₄–SbCl₅–H₂O. The electrical conductivity and optical transmission of tin oxide films were studied with antimony doping. The film conductivity increased largely without losing optical transparency with a small addition of antimony. The increase of the conductivity was attributed mainly to more electrons donated by pentavalent Sb ions in the SnO₂ lattice. Large additions of antimony, however, diminished the conductivity, optical transparency, and crystallinity of the film. The diminution was found to be caused by fine Sb₂O₅ phases codeposited with SnO₂.     

Effect of adsorptive gaseous reactant on non-isothermal behavior for gas-solid reactions

The effect of adsorptive species on non-isothermal gas-solid reactions is studied on the basis of Langmuir-Hinshelwood kinetics. The concept of an effectiveness factor provides good information to ascertain the effect of adsorptive species and the transition of the rate controlling regime, in connection with the parameters, generally used in the analysis of non-isothermal behavior. For highly exothermic reactions, the effectiveness factor-Thiele modulus curves with multiple solutions are presented with respect to the modified adsorption equilibrium constant. The variations of the rate-controlling regime by the effect of adsorptive species are also discussed.     

A new characterization procedure for aqufous solutions with unknown composition

A new characterization procedure for aqueous solutions with unknown composition was proposed based on the binomial distribution of TOC (total organic carbon) fraction in terms of a characterizing variable, the Freundlich coefficient, k, so that the solution in question can be described by a finite number of pseudo.species identified with a certain k value. The validity and computational accuracy of this procedure has been demonstrated by characterizing three sets of experimental data chosen from different sources. Predictions based on this procedure yielded acceptable results that agreed closely with experimental data.     

Diffusional interference in liquid phase counter-adsorptions

A surface diffusion mocel with diffusional interference has been presented for the analysis of multicomponent adsorption of phenols by activated carbon. Surface diffusion coefficients for multicomponent adsorptions were estimated from the relationship between. the surface diffusion coefficient of each species and the surface coverage. The diffusional interference coefficients, W_ij, was determined from experimental counter-adsorption data. The numerical values of W_ij were in the range of 0.4–0.9, which show that the introduction of diffusional interference is necessary to analyze multicomponent counter-adsorptions properly. The proposed model successfully simulates the behaviour of phenols-activated carbon system in a batch adsorber.     

Enhanced utilization bound of Rate-Monotonic scheduling in Controller Area Networks

When priorities to message streams are assigned using Rate Monotonic (RM) for a Controller Area Network (CAN), the utilization bound is known to be about 25% for CAN 2.0A and 29% for CAN 2.0B. In this letter, we present a higher utilization bound than the existing ones with a reasonable constraint. The new utilization bounds are approximately 34% for CAN 2.0A and 41% for CAN 2.0B if no single message stream's utilization exceeds 46% or 27% of the total utilization for CAN 2.0A or CAN 2.0B, respectively.     

Semi-annual cycle of sea-surface temperature in the East/Japan Sea and cooling process

Semi-annual cycles of the sea-surface temperature (SST) in the East/Japan Sea (EJS) and their forcings were examined by analysing National Oceanic and Atmospheric Administration/Advanced Very-High-Resolution Radiometer data, scatterometer wind vectors, and heat flux data. The semi-annual cycle contributed to the total variance of the SST by 8% and amounted to 25% of the amplitudes of the annual SST cycle, particularly in the Tatarskiy Strait and along the continental shelf off Russia. The lowest phase, corresponding to the minimum SST, occurred during early November and 6 months earlier in May or June depending on the position. The forcings of the semi-annual cycle were not semi-annual but substantially annual with a lag of 6 months, which gave rise to SST cooling in spring and autumn. Our analyses illustrated that SST cooling in autumn was caused by direct, local atmospheric wind forcings, whereas the cooling with large amplitudes of the semi-annual cycle in spring was caused by the non-local, remotely forced cold water advection of the Liman Current associated with sea-ice melting in the Tatarskiy Strait. The phase lag of 1–2 months between the complete melting of the sea ice in the Tatarskiy Strait and the surface cooling along the Russian continental shelf was related to the advection of cold water from sea ice in the form of the Liman Cold Current. The semi-annual cycle also resulted from asymmetry of the time series of the SST due to a long cold winter and a short warm summer. To understand how SST curves are distorted and asymmetric, we suggested two mathematical parameters of kurtosis and skewness. In addition, we suggest that the ratio of the semi-annual amplitude to the annual amplitude of SST harmonics can be used as a typical indicator of the asymmetry in year-to-year SST variations.     

The use of non–physical standards in colour communication and matching

As a result of developments in spectrophotometry, together with improved accuracy in computer colour matching and laboratory dyeing, non–physical standards (reflectance data) can now be used for the successful communication, matching and quality control of colour. In colour palette generation, ‘matching by numbers’ has become a reality.     

Influence of Substrate Type on Level Dyeing of Acrylic Yarn Packages

In an earlier paper [1], the influence of flow rate, ramp (constant rate of temperature rise) and package density on the rates of dyeing of two basic dyes on Ex/an, and on the levelness obtained in the resulting dyeings, was investigated, and a relationship was derived to link these factors quantitatively. This work has now been extended to cover the behaviour of various basic dyes on Exlan and other acrylic fibres, under conditions expected to give borderline levelness. It has been shown that the shape of the rate–of–dyeing curve depends on the type of acrylic fibre and, to a lesser extent, on the cationic retarder used, but not on dye type within the group of CV2. 5–3. 5 basic dyes examined. The response of dyeing rate and degree of unlevelness to deliberate variations of ramp, as demonstrated in the previous work on Exlan, is now confirmed on Cashmilon. Evidence of a different type of random unlevelness, not related directly to dyeing rate, was also obtained from dyeings on the various fibres at a slow ramp.