Grafting acrylic acid monomer to poly-(vinyl alcohol) and methyl cellulose by ceric ion

A graft copolymer of acrylic acid on poly(vinyl alcohol) was prepared by use of the ceric ion–polyol redox system in aqueous medium. The graft copolymer obtained was water-soluble under the specified experimental conditions. The efficiency of grafting was determined by measuring carboxyl group content (as expected from acrylic acid unit) in the copolymer by applying the newly developed reverse dye-partition technique. The graft copolymer was also characterized by viscosity and solubility measurements. The effect of varying concentration of catalyst, monomer, and grafting time has also been determined.     

Remote cure monitoring of epoxy materials using optical techniques

A remote all-optical technique for the generation and detection of ultrasonics in materials is described. This technique uses a robust wideband optical fiber interferometer for detection. Using this interferometer, non-contact measurements of ultrasonic propagation times in epoxy materials are reported throughout the complete cure cycle.     

Anomalous density and refractive index variation of a nematic liquid crystal

This paper reports the results of the measurement of refractive indices and densities of p-ethoxyphenyl trans-4-butyl cyclohexane carboxylate at different temperatures. The molecular polarizabilities have been calculated from refractive indices using Vuks' formula and orientational order parameters are determined from the polarizability values. The order parameter values have been compared with those obtained from Maier-Saupe theory. The compound shows anomalous behaviour regarding variation of density, ordinary refractive index and order parameter values with temperature. This is consistent with our previous X-ray study of this compound. The possible reason for this peculiar behaviour has been discussed.     

Half-monopoles in the Yang-Mills theory

Using a gauge-invariant characterization of monopoles defined via their centres, we investigate the generic topological field pattern for the three-dimensional Yang-Mills theory. This leads to field patterns with one-half winding number. After presenting the main features through the simpler case of half-vortices, we consider half-monopoles in detail.     

Domain width from ferromagnetic resonance in single crystal nickel films

Two resonances have been observed during ferromagnetic resonance measurements on strained single crystal nickel films at 132 K and at a microwave frequency 17 GHz. The lower field line can be interpreted as due to a multidomain structure. Multidomain analysis gives a value of the domain width, w = 1.6 ± 0.1 × 10^-5 cm, which is in agreement with the result from a different method.     

Linear,Integer, Separable and Fuzzy Programming Problems: A Unified Approach towards Reformulation

For mathematical programming (MP) to have greater impact as a decision tool, MP software systems must offer suitable support in terms of model communication and modelling techniques. In this paper, modelling techniques that allow logical restrictions to be modelled in integer programming terms are described, and their implications discussed. In addition, it is illustrated that many classes of non-linearities which are not variable separable may be, after suitable algebraic manipulation, put in a variable separable form. The methods of reformulating the fuzzy linear programming problem as a max-min problem is also introduced. It is shown that analysis of bounds plays a key role in the following four important contexts: model reduction, reformulation of logical restrictions as 0-1 mixed integer programmes, reformulation of non-linear programmes as variable separable programmes and reformulation of fuzzy linear programmes. It is observed that, as well as incorporating an interface between the modeller and the optimizer, there is a need to make available to the modeller software facilities which support the model reformulation techniques described here.     

Perfluoralkyl-Derivate von N. 41. Mitt. Vernetzung von Nitrosokautschuk mit Perfluor-2,5-diazahexan-2,5-dioxyl und dessen Derivaten

Ohne Zusammenfassung     

Vibrational spectra of fluorohafnate glass

We report the first detailed measurements of fundamental vibrational spectra in fluorohafnate glass. The Raman spectrum is dominated by a single relatively broad peak in the vicinity of 570–590 cm^?1 attributed to Hf-F stretching modes, while the infrared spectrum displays two prominent broad peaks. The location of the high frequency peaks is shown to be consistent with the observed position of the infrared absorption edge.