Electrosorption and inhibition properties of p-norborn2-yl phenolate ions at the mercury/solution interface

The electrosorption properties of p-norborn-2-yl phenolate ions in alkaline solutions were investigated by ac polarographic and electrocapillary measurements.

Two adsorption regions were found. At low bulk surfactant concentrations the adsorption at the positively charged electrode (−0.2 E −0.6 V) is predominant while at higher surfactant concentrations the adsorption at the negatively charged electrode (−0.6 E −1.0 V) is more pronounced. At E = −0.40 V the adsorption parameters were determined (a ≈ 2; ΔG°_A = −32.5 ± 1 kJ mol⁻¹. Between −0.6 E −1.0 V one potential of maximum adsorption for all concentrations does not exist and therefore the adsorption parameters could not be calculated.

At E = −0.40 V progressive two-dimensional nucleation with a nucleation order of 3 was observed which corresponds well with the high attraction constant.

The electrode reaction S₂O²⁻₈ + 2e⁻ → 2 SO²⁻₄ is inhibited by norborn-2-yl phenolate ions in the potential range −0.2 E −0.6 V. In the second potential range of capacity decrease the electrode process is much less retarded. At E = −0.40 V, in a similar manner as described for neutral molecules, a linear dependence of the log k_s (k_s apparent rate constant) on ln c_A and π (π = surface film pressure), respectively, has been found.     

Particulate Analysis Instrumentation for the Cement Industry

At present, even though most cement plants are computer controlled, they depend on manual particle analysis and feed settings. Automatic process control through the use of continuous particle size analysis can provide the maximum obtainable throughput at optimum particle size. A new particle size measurement technology using a helium-neon laser and a unique optical filtering system has been reported previously. Fourier diffraction patterns of particles in the 2176 micron range are utilized to produce a 13 channel histogram of the complete particle size distribution. The histogram data are used to compute many parameters of the size distribution, such as, equivalent surface area, median, mean, and percent passing a number of micron sizes. A family of particle size instrumentation has been developed using this technology for both off-line quality control and on-line process control. The design of this equipment and its operation is described. In addition, experimental data are presented comparing the fineness measurements of Portland cement obtained by air permeability apparatus and those of the MICROTRACTM equipment.     

Stable and convergent iterative feedback tuning of fuzzy controllers for discrete-time SISO systems

This paper proposes new stability analysis and convergence results applied to the Iterative Feedback Tuning (IFT) of a class of Takagi–Sugeno–Kang proportional-integral-fuzzy controllers (PI-FCs). The stability analysis is based on a convenient original formulation of Lyapunov’s direct method for discrete-time systems dedicated to discrete-time input affine Single Input-Single Output (SISO) systems. An IFT algorithm which sets the step size to guarantee the convergence is suggested. An inequality-type convergence condition is derived from Popov’s hyperstability theory considering the parameter update law as a nonlinear dynamical feedback system in the parameter space and iteration domain. The IFT-based design of a low-cost PI-FC is applied to a case study which deals with the angular position control of a direct current servo system laboratory equipment viewed as a particular case of input affine SISO system. A comparison of the performance of the IFT-based tuned PI-FC and the performance of the PI-FC tuned by an evolutionary-based optimization algorithm shows the performance improvement and advantages of our IFT approach to fuzzy control. Real-time experimental results are included.     

Proof Complexity of the Cut-free Calculus of Structures

We investigate the proof complexity of analytic subsystems ofthe deep inference proof system SKSg (the calculus of structures).Exploiting the fact that the cut rule (i) of SKSg correspondsto the ¬-left rule in the sequent calculus, we establishthat the ‘analytic'system KSg+c has essentially the samecomplexity as the monotone Gentzen calculus MLK. In particular,KSg+c quasipolynomially simulates SKSg, and admits polynomial-sizeproofs of some variants of the pigeonhole principle.     

Constrained Sintering of Alumina Thin Films: Comparison Between Experiment and Modeling

Alumina thin films deposited by dip coating on alumina substrates were sintered between 1150° and 1350°C. A new measuring system using a rocking arm as a mechanical amplifier allows in situ measurement of the shrinkage of the film. Comparison of experimental densification behavior with the predictions of the isotropic continuum mechanics model (using values of constitutive parameters determined by sinter forging) highlights the inadequacy of the isotropic models. These results, together with other published evidence, provide justification to consider anisotropic models.     

ASSL: A Software Engineering Approach to Autonomic Computing

ASSL provides a framework for formal specification, validation, and code generation of autonomic systems.     

Optimization and Multihazard Structural Design

There is a growing interest in the development of procedures for the design of structures exposed to multiple hazards. The goal is to achieve safer and/or more economical designs than would be the case if the structures were analyzed independently for each hazard and an envelope of the demands induced by each of the hazards were used for member sizing. We describe an optimization approach to multihazard design that achieves the greatest possible economy while satisfying specified safety-related and other constraints. We then present an application to illustrate our approach.     

Impulse plasma deposition of magnetic nanocomposite layers

The most characteristic feature of the IPD method is that the synthesis proceeds in the impulse plasma itself, with the participation of ions. The IPD growth mechanism, originating from clusters of constituent materials, makes this method particularly suitable for the fabrication of nanocomposite layers.The material synthesised in the present experiment was an Fe-Ti alloy. The sources of Fe and Ti were the internal electrodes of two independent impulse plasma accelerators operated in an alternate mode. It appeared that the Fe-Ti alloy forms at the interface between the Fe and Ti nanocrystals as a result of the surface diffusion due to the coalescence of the nanocrystals.     

Synthesis of polyurethane cationomers with anil groups: intramolecular proton transfer in salicylideneanil structures

Three new o‐hydroxy Schiff bases, 2‐chloromethyl‐N‐(2‐hydroxybenzilidene)aniline, 3‐(11‐bromoundecanoyloxymethyl)‐N‐(2‐hydroxybenzilidene)aniline and 4‐chloromethylphenyl (carbamoyloxymethyl‐2‐hydroxybenzylidene)aniline, used as quaternization agents for a polyetherurethane precursor based on poly(tetramethylene oxide) diol of 2000 g mol^?1 average molar mass (PTMO), 2,4‐toluene diisocyanate and N‐methyldiethanolamine (1:3:2 molar ratio), have been synthesized in order to obtain polymeric films with fluorescent properties. The structure and the photochromic mechanism of the salicylideneanil units were investigated. The excited state intramolecular proton‐transfer process (ESIPT) with the cis‐ and trans‐keto isomers formation as intermediate compounds and the formation of a keto tautomer were evidenced by a large Stokes shifted emission (100 nm). Copyright © 2005 Society of Chemical Industry