Dynamic radiation force of acoustic waves on solid elastic spheres

The present study concerns the dynamic radiation force on solid elastic spheres exerted by a plane wave with two frequencies (bichromatic wave) considering the nonlinearity of the fluid. Our approach is based on solving the wave scattering for the sphere in the quasilinear approximation within the preshock wave range. The dynamic radiation force is then obtained by integrating the component of the momentum flux tensor at the difference of the primary frequencies over the boundary of the sphere. Results reveal that effects of the nonlinearity of the fluid plays a major role in dynamic radiation force leading it to a parametric amplification regime. The developed theory is used to calculate the dynamic radiation force on three different solid spheres (aluminium, silver, and tungsten). Resonances are observed in the spectrum of the force on the spheres. They have larger amplitude and better shape than resonances present in static radiation force.Comment: 9 pages, 4 figures, to appear in Physical Review

Electron Microscopy of Organic Thin Films

Thin films of organic materials are increasingly being used for technological applications. In this study two methods of thin film production, Physical Vapour Deposition (PVD) and Solution Casting on a water surface, have been used to prepare thin films of organic materials for investigation by Transmission Electron Microscopy. The polycyclic aromatic compounds perylene and quaterrylene were evaporated under high vacuum onto the (001) face of a freshly cleaved crystal of KCl. Substrate temperature was shown to play a important role in determining the crystallinity and morphology of the thin film produced. An optimum substrate temperature was found at which deposited crystals were smooth, formed large domains and did not undergo re-evaporation from the substrate. Lattice images were obtained for the quaterrylene and some image processing was attempted. The second class of compounds studied were a range of octasubstituted phthalocyanines that were synthesised. These compounds are potential one dimensional conductors since they stack in a "face to face" manner allowing good n-orbital overlap. The compounds prepared were all based on the octa-dodecyloxy-phthalocyanine unit and were the metal free, copper, silicon-dihydroxy and polysiloxane derivatives. Films of these compounds could be prepared by allowing a chloroform solution of these compound to evaporate on a water surface. Information was obtained by electron diffraction and by lattice imaging. The most common packing arrangement was for a stack of molecules to lie parallel to the water surface. The molecules in the stack could be either tilted or perpendicular to the stack. Only the copper derivative showed any evidence of lying flat on the water surface. The unusual packing of these molecules was explained in terms of the strong hydrophobic interaction between the paraffin side chains and the water surface

Compte rendu de The pearl frontier. Indonesian labor and indigenous encounters in Australia’s northern trading network, de Julia Martínez & Adrian Vickers

The authors are to be commended on the extensive and meticulous research that went into producing this book, on an industry and time in Australia’s history that is little remembered today, and even less understood. The book is not just about pearling and trading, but explores in depth Australia’s relationship with its nearest Asian neighbors, particularly during the century from the mid-1800s to the mid-1900s. I kept having flashes of recognition of still-current exploitation of the powerless..

Joining forces: European periodical studies as a new research field

In recent decades, periodical studies have burgeoned into a vibrant field of research. Increasing numbers of scholars working in disciplines across the humanities — literary studies, history, art history, gender studies, media studies, legal history, to name a few — are exploring the press as a key site for cultural production, public debate and the dissemination of knowledge. [...

Annie Sartre-Fauriat & Maurice Sartre, Le plateau du Trachôn et ses bordures (Inscriptions Grecques et Latines de la Syrie XV/1, XV/2, BAH 204)

This work is a welcome addition to the IGLS series, covering in two excellent well-presented volumes all the known Greek and Latin inscriptions of the modern day Lejā, the basalt plateau to the south of Damascus known in ancient times as Trachôn. The material collected in these two volumes is a combination of previously known inscriptions, re-edited where appropriate, and over 200 newly discovered inscriptions. The task of collecting and publishing together the pre-existing evidence would by ..

The UK Ceramic Marketing Strategy in response to globalization.

Also based on my current research, the 2013 Conference of Historical Analysis and Research in Marketing (CHARM) have accepted my research paper on UK ceramics and globalization. My paper has also been accepted for publication in their Proceedings, to be published at the time of the Conference

UK Ceramic Manufacturing strategies, marketing and design in response to globalization c1990-2010.

My research is considering the impact of the Far East on the UK Ceramic Industry, design, marketing and consumption, c1990-2010. The Conference is jointly organised by Parsons and Cooper-Hewitt, National Design Museum, and one of the themes is ‘Globalization and the mobility of cultural products’. The title of my paper is ‘UK ceramic manufacturing strategies, marketing and design in response to globalization c1990-2010’. This is a prestigious event run by a world renowned design school. I was invited by Dr.Ethan Robey, Assistant Professor of the History of Decorative Arts and Design, Associate Director, MA Program in the History of Decorative Arts and Design

The Harmonic Balance Method with arc-length continuation in rotor/stator contact problems

International audienceThere are a variety of abnormal running conditions in rotating machinery which lead to rotor/stator interaction dynamics which, in turn, can cause a rich mixture of effects associated with rub-related phenomena. These effects manifest themselves in the occurrence of multiple solutions for steady-state vibration response scenarios , including amplitude jumps during rotor acceleration, and vibration responses at different/multiple frequencies of excitation forces such as imbalance. This paper describes a numerical algorithm based on the harmonic balance method to calculate the periodic response of a non-linear system under periodic excitation. The algorithm also calculates the stability of the periodic solutions found, marks turning and bifurcation points, and follows a solution branch over varying system parameters via arc-length continuation