Why Hybrid Meson Coupling to Two S-wave Mesons is Suppressed

We introduce strong interaction selection rules for the two-body decay and production of hybrid and conventional mesons coupling to two S-wave hybrid or conventional mesons. The rules arise from symmetrization in states in the limit of non-relativistically moving quarks. The conditions under which hybrid coupling to S-wave states is suppressed are determined by the rules, and the nature of their breaking is indicated.Comment: 9 pages, LaTeX, 1 eps figures, uses epsf. Minor modifications, Title chang

The ammonolysis of esters in liquid ammonia

The rates of ammonolysis of alkyl benzoate and phenylacetate esters in liquid ammonia increase with the acidity of the leaving group alcohol and show relatively large Brønsted βlg values of −1.18 and −1.34, respectively, when plotted against the aqueous pKa of the alcohol. The Brønsted βlg obtained using the pKa of the leaving group alcohol in liquid ammonia is significantly reduced to ~ −0.7, which indicates that the rate-limiting step involves a reaction of the tetrahedral intermediate with little C–OR bond fission in the transition state. The solvolysis reaction is subject to significant catalysis by ammonium ion, which, surprisingly, generates a similar Brønsted βlg indicating little interaction between the ammonium ion and the leaving group. It is concluded that the rate-limiting step for the ammonium-ion-catalysed solvolysis of alkyl esters in liquid ammonia is the diffusion-controlled protonation of the zwitterionic tetrahedral intermediate T+- to give T+, which is rapidly deprotonated to give T0 which is compatible with the rate-limiting step for the uncatalysed reaction being the formation of the neutral T0 by a ‘proton switc

Haptic holography/touching the ethereal

Haptic Holography, was perhaps, first proposed by workers at MIT in the 90s. The Media Lab, headed up by Dr. Stephen Benton, with published papers by Wendy Plesiak and Ravi Pappuh. −1 Recent developments in both the technology of digital holography and haptics have made it practical to conduct further investigations. Haptic holography is auto-stereoscopic and provides co-axial viewing for the user. Haptic holography may find application in medical & surgical training and as a new form of synthetic reality for artists and designers. At OCAD's PHASE Lab (Prototypes for Holographic Art and Science Explorations) workers are exploring hybrid forms of augmented reality, that combine haptics, interactivity and auto-stereoscopic imagery. Conventional Haptic environments, while presenting a 3D physics environment, typically provide a 2D visual work/play space. Orienteering in such an environment creates an uncertain spatial relationship for the user. Our group creates 3d models from which we create holographic constructs. The same model is used to create the physics environment. The two models are super-imposed. The result: Holograms you can touch

Magnetic Force Microscopy of Magnetic Nanoparticles

Presented here is a summary of the improvements made to a standard magnetic force microscope for the imaging and spatial localization of magnetic nanoparticles. This thesis outlines the steps necessary for distributing magnetic nanoparticles onto a substrate, determining their characteristics, and designing a magnetic field stage for applying external magnetic fields in conjunction with magnetic force microscopy. Initial results are shown along with theoretical simulations for interpretation of the data.No embarg

Visualization of complex medical data using next-generation holographic techniques

The next generation of holo-video and high quality, direct-write holographic techniques have the potential to aid doctors, medical workers, students and diagnosticians in understanding complex medical conditions, and it may even save lives. Medical holograms could translate data, from existing sources such as DICOM format, to hard copy dimensional visualizations, in order to better represent anatomical information for purposes of analysis, diagnostics and healthcare records. The medical hologram system we propose will print the data from DICOM (Digital Imaging and Communications in Medicine) using the next generation of direct-write systems

Localist models are compatible with information measures, sparseness indices and complementary learning systems in the brain

This is an Accepted Manuscript of an article published by Taylor & Francis in Language, Cognition and Neuroscience on 17 November 2016. The version of record is available online: http://www.tandfonline.com/10.1080/23273798.2016.1256491In this paper, I express continued support for localist modelling in psychology and critically evaluate previous studies that have sought to weaken the localist case in favour of models with thoroughgoing distributed representation. I question claims that information measures and sparseness indices derived from single-cell recording data are supportive of distributed representation and show that the patterns observed in those data can be reproduced from simulations of a model that is known to be localist. I also set out some logical objections to the complementary learning hypothesis, particularly in as much as it is used to justify thoroughgoing-distributed models of the cortex.Peer reviewedFinal Accepted Versio