Free and bound triacontanol in tea leaves

A direct gas chromatographic method of identification and determination of 1-triacontanol, a plant growth substance, in tea leaves is reported. Treatment of the tea leaves with calcium oxide releases more triacontanol, showing that the compound occurs also in a bound form in tea leaves.     

Sliding wear behavior of nanocrystalline nickel coatings: Influence of grain size

In the present study the sliding wear behavior of pulse electrodeposited nanocrystalline Ni coatings as a function of grain size including bulk annealed Ni has been systematically studied using pin-on-disc configuration against the WC-Co counter body. The sliding wear has been analyzed with respect to wear rate, coefficient of friction, subsurface deformation and composition of wear debris. The result indicates that the sliding wear rate and coefficient of friction of Ni decreases with decreasing grain size. The subsurface beneath the worn pin surface is composed of a near surface shear region and beneath it a region of bulk plastic deformation. The ratio of the depth of the shear region to the depth of bulk deformed region decreases with decreasing grain size indicating a greater localization of near surface deformation with decreasing grain size.     

Rupture Strength of some Mould Flux Slag Films relevant to Swedish Continuous Casting Practice

In this paper, the high temperature rupture strengths of some solid mould flux slag films in Swedish continuous casting processes are presented. The apparatus, designed and constructed in the present laboratory is based on the principle that the solidified film of the mould flux slag is subjected to elongation stress at temperatures below the solidus points of the fluxes. The rupture strength tests were conducted in air. The results indicate that the rupture strength is dependent on the extent of polymerization of the silicate network. The results of Raman spectra studies of the mould flux slags used in the present work were corroborated by estimations of the NBO/T ratios of the slags. It was found that lower NBO/T ratios in the slag led to higher rupture strengths. Earlier measurements of the viscosities, thermal diffusivities as well as stress relaxation results for the same slags followed a similar trend indicating the dependency of these properties on the slag structure and a clear link between thermophysical and mechanical properties of slags. The results are expected to provide some basic guidelines to develop the next‐generation mould flux and modelling of the continuous casting process.     

A token-based routing mechanism for GMPLS-controlled WDM networks

This paper analyzes destination initiated reservation for Generalized Multi-Protocol Label Switching (GMPLS) based wavelength division multiplexing (WDM) networks and determines, via simulation, probabilities of both forward blocking and backward blocking. During light traffic load, any degradation in performance is due to backward blocking, whereas during heavy traffic load forward blocking dominates. In order to minimize performance degradation due to blocking, this paper proposes a token based routing scheme that is capable of searching for the availability of more than one route from source to destination, meeting the desired quality of service (QoS). Extensive simulation results show that the proposed technique significantly improves the blocking performance and setup delay.     

Ordered mesoporous silica fibers: effects of synthesis conditions on fiber morphology and length

Ordered mesoporous silica fibers offer potential industrial application in several areas including polymerization catalysis and separation. Understanding the effects of synthesis conditions on these fibers prepared by the interfacial self-assembly growth method is important to their production and application. The focus of this work is to understand the effect of two previously unstudied factors: silica source height (tetrabutylorthosilicate, TBOS) and the humidity, on the formation of ordered mesoporous silica fibers by the interfacial self-assembly method. Here the TBOS content, interface area, height of source, and humidity of the environment were varied to study their effect on fiber growth. The results show that the TBOS content and interface area do not have a significant impact on results of ordered mesoporous silica fibers. Increasing silica source height or environmental humidity, which lowers the water evaporation rate, gives silica fibers with lower length, less ordered inner pore structure and macroscopic morphology, and smaller pore size. Attempts to mix the growth medium eliminate the fiber morphology and yield gyroidal shapes. A mechanism that combines evaporation of water resulting in local concentration and surfactant, self-assembly, and reaction and diffusion of silica source is proposed to describe the formation of ordered mesoporous silica fibers.