In this study, the crystallization behavior of a 65GeO2-15PbO-10MgF2-10MgO glass (prepared by the conventional melt quenching technique) has been investigated. The microstructure and crystallization behaviors of this glass were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), non-isothermal differential thermal analysis (DTA) and Fourier transform infrared spectr...

From the accumulated results of several research groups over the last 25 years, it is clear that photoinduced electron-transfer reactions have significantly broadened the scope of organic photochemistry.1 The fundamental mechanistic principle is that when quenching of an excited state via electron transfer is sufficiently exothermic, the reaction occurs at or close to the diffusion-controlled l...

With use of a specially designed gradient-generating system, of anion-exchange resins of 10-20 mum particle diameter, and of an orcinol solution in concentrated sulfuric acid (1 g/liter) as detection reagent, a mixture of 16 carbohydrates can be separated in less than 4 h. The limit of detection for most sugars is in the 0.1--2.0 nanomole range. The detection reagent is stable for months and do...

This paper propose a relatively simple adaptive control (in the presence of input constraints) for a class of nonlinear distributed parameter models with application to a nonisothermal exothermic chemical tubular reactor with axial dispersion. Our objective is to regulate the reaction temperature in a prespecified neighborhood of a given reference temperature. we apply a λ-tracking controller, ...

A prediction method for rubber curing process has historically received considerable attention in manufacturing process for rubber article with relatively large size. In recent years, there exists increasing demand for simulation driven design which will cut down the cost and time required for product development. In case of the rubber with relatively large dimensions, low thermal conductivity ...

Abstract In this study, perfluorobutyl iodide (PI) and glycidyl azide polymer (GAP) were used to synthesize perfluorobutane (PGAP) coated on aluminum powder form Al@PGAP. PGAP, an energetic fluoride, was explore the combustion promotion of powder. The Al@PGAP showed better thermal reaction performance. exothermic enthalpy increased by about 1.5 times, with higher heat, lower ignition temperatur...

This article is devoted to the investigation of Marangoni-driven pattern formation at the interface between two immiscible fluids filling a Hele-Shaw cell, each of them containing a reactant of an exothermic neutralization reaction. In such a system, convective patterns arise when one reactant diffuses through the interface to react with the other chemical species in one of the fluids. A chemo-...

We consider the influence of heat losses through the walls of a Hele-Shaw cell on the linear stability and nonlinear dynamics of exothermic chemical fronts whose solutal and thermal contributions to density changes have the same signs. Our analysis is based on the reaction-diffusion-convection equations obtained from the Darcy-Boussinesq approximation. The parameters governing the equations are...

It is well known that both urea and acid cause collagen fibres to swell and at high conentrations to denature (Rigby, 1961). The mechanisms by which these reactions occur are not well understood. Paz Andrade et al. (1975) have used microcalorimetry to study the reaction between urea and some globular proteins, and have interpreted the results in terms of the binding of urea to the peptide units...

Citric acid added as set retarder significantly contributed to enhancing the setting temperature and to extending the thickening time of a calcium aluminate phosphate (CaP) geothermal cement slurry consisting of calcium aluminate cement (CAC) as the base reactant and sodium polyphosphate (NaP) solution as the acid reactant. The set-retarding activity of citric acid was due to the uptake of Ca2'...