Grafting of silica during the processing of silica‐filled SBR: Comparison between length and content of the silane

The treatment of nanoscopic silica grafted in the blend during the processing of silica‐filled styrene butadiene rubber was performed with silane, introduced at different concentrations, or at a constant concentration with a given length of alkyl chain. From swelling measurements in water and in solvent, the maximum silane content that can be grafted has been calculated as a function of the length of the silane alkyl chains as well as their efficiency to cover the silica surface. The found values are close to the values found in the literature for grafting in solution. Moreover, a direct correspondence between the length of the silane alkyl chains and their concentration has been deduced. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 143–152, 2006     

On the ionization potential of a solute molecule in hydrocarbon solutions: Effect of temperature and phase

It is shown that the ionization potential I of N,N,N′,N′-tetramethylparaphenylenediamine (TMPD) dissolved in several hydrocarbons is constant in the solid phase from 77 K up to the melting point T_M and suffers an abrupt decrease at this temperature ranging from 0.65 eV for tetramethylsilane to 0.42 eV for n-hexane. The meaning of the I jump at T_M is discussed. From the invariance of I, it is concluded that the energy of the excess electron, V₀, is constant in the solid phase.     

Modification of bovine beta-lactoglobulin by glycation in a powdered state or in aqueous solution: adsorption at the air-water interface

The adsorption at the air-water interface of native and various glycated forms of beta-Lactoglobulin B (beta-LG), prepared under two different experimental conditions, was investigated by ellipsometry, surface tension and shear elastic constant measurements. The measurements were performed in 0.1 M phosphate buffer, 0.1 M NaCl, pH 6.8. It was found that the interfacial properties of beta-LG were more affected when the glycation was performed in solution than in the dry-way system. Dry-way glycated beta-LG, despite a higher glycation extent, affected slightly its interfacial behaviour. Solution glycated beta-LG exhibited a higher adsorption and more rigid interface as expressed by shear elastic constant measurement at saturation (16.5 mN/m against 8.7 and 11.5 mN/m for native and control treated beta-LG, respectively). These results were attributed to the specific molecular species induced during glycation in solution, which includes monomers and unfolded covalent homodimers of beta-LG molecules with a high tendency to self-association via non-covalent interactions.     

Experiments in mixed-integer linear programming using pseudo-costs

This paper discusses heuristic branch and bound methods for solving mixed integer linear programming problems. The research presented on here is the follow on to that recorded in [3].After a resumé of the concept of pseudo-costs and estimations, new heuristic rules for generating a tree which make use of pseudo-costs and estimations are presented. Experiments have shown that models having a low percentage of integer variables behave in a radically different way from models with a high percentage of integer variables. The new heuristic rules seem to apply generally to the first type of model.Later, other heuristic rules are presented that are used with models having a high percentage of integer variables and with models having a special structure (models including special ordered sets.)The rules introduced here have been implemented in the IBM Mathematical Programming System Extended/370. They are used to solve large mixed integer linear programming models.Numerical results that permit comparisons to be made among the different rules are provided and discussed.     

Facile synthesis of 2-bromo-3-fluorobenzonitrile: an application and study of the halodeboronation of aryl boronic acids

A scaleable synthesis of 2-bromo-3-fluorobenzonitrile via the NaOMe-catalyzed bromodeboronation of 2-cyano-6-fluorophenylboronic acid was developed. The generality of this transformation was demonstrated through the halodeboronation of a series of aryl boronic acids. Both aryl bromides and aryl chlorides were formed in good to excellent yields when the corresponding aryl boronic acid was treated with 1,3-dihalo-5,5-dimethylhydantoin and 5 mol % NaOMe.     

The Photochemical and Thermal Interconversion of Some Cyclopentadienone Dimers

In continuation of previous work on cyclopentadienone dimers [3], thermal and photochemical interconversions of the isomeric diketones 1, 3 , and 5 by skeletal rearrangements have been established to the extent summarized in schemes 2 and 3, and the intramolecular [2+2] cycloaddition 1 → 2 was found to be reversible photochemically.     

Light level control in birefringent fibres through thermal stress effects caused by the absorption of broadside incident light: a single-ended fibre-optic system

In this paper, light level control is demonstrated using optically induced thermal stress effects in a polarization-maintaining optical fibre. The controlling light beam is absorbed by a blackened segment of the fibre and produces local heating. Light control is demonstrated in the single-ended sensor configuration, which displays a response that cannot be explained from phase delays only, but requires the addition of the coupled mode theory.