Preliminary study of the thermally stimulated blue luminescence of ulexite

In this paper, novel results on the blue thermally stimulated luminescence (TSL) emission of ulexite (NaCaB₅O₆(OH)₆·5H₂O) have been studied. The four maxima appearing at 60, 110, 200 and 240°C on the TSL glow curves of this borate could be respectively associated to: (i) the first dehydration (NaCaB₅O₆(OH)₆·5H₂O→NaCaB₅O₆(OH)₆·3H₂O), (ii) the creation-annihilation of the three-hydrated phase, (iii) the Na-coordinated chains dehydroxylation and the starting point of the alkali self-diffusion through the lattice and (iv) the amorphisation of the lattice. These results are fairly well correlated with the differential thermal analyses (DTA), in situ thermal observations under environmental scanning electron microscope (TESEM) and thermal X-ray diffraction (TXRD) techniques.     

Radiation from modes of a rectangular panel into a coupled fluid layer

Modal radiation efficiencies are evaluation for a rectangular panel which is simply supported in an infinite baffle and coupled to a fluid layer. The analysis is based on the calculation of the acoustic power radiated into the layer by the panel vibrating in one of its in vacuo natural modes. At low frequencies, the efficiency is inversely proportional to the layer depth; at high frequencies, it exhibits a complex, multiple peak characteristic, associated with the acoustic field of the layer. Comparison with the modal radiation efficiencies of a panel coupled to a fluid half-space shows a similar dependence on mode order and panel dimensions.     

The flexural vibration of a line-stiffened plate with fluid loading,part I: Analysis

This paper considers the vibration of a symmetrical system consisting of an infinite fluid loaded plate bearing a finite number of parallel stiffeners. The system is driven at the central stiffener by a travelling wave line force. Formal solutions for the equations of motion are found in terms of cosine transforms. Manipulation of the equations allows the problem to be reduced to the solution of a set of linear algebraic equations in the vibration amplitudes at the stiffeners. The coefficients in these equations depend in a simple way upon the stiffener parameters, and upon particular values of the cosine transform of a function which depends only on the plate and fluid parameters, and the stiffener positions.     

Hexaphenylbenzene as a rigid template for the straightforward syntheses of "star-shaped" glycodendrimers

Original glycodendrimers emanating from propargylated hexaphenylbenzene cores and containing up to 54 peripheral sugar ligands have been synthesized by Cu(I)-catalyzed [1,3]-dipolar cycloadditions using both convergent and divergent approaches.     

Distorted cylindrical shell response to internal acoustic excitation below the cut-off frequency

The mechanism of coupling between a plane wave acoustic mode and a non-axisymmetric structural mode of a thin walled, circular, cylindrical shell, via the geometrical distortion of the shell, is considered. A theoretical model of response below the acoustic cut-off frequency is used to estimate the vibration level induced in a tube having small circumferential variations of wall thickness, radius and modulus of elasticity. The results have been confirmed experimentally.