393 research outputs found
Is copyright blind to the visual?
This article argues that, with respect to the copyright protection of works of visual art, the general uneasiness that has always pervaded the relationship between copyright law and concepts of creativity produces three anomalous results. One of these is that copyright lacks much in the way of a central concept of 'visual art' and, to the extent that it embraces any concept of the 'visual', it is rooted in the rhetorical discourse of the Renaissance. This means that copyright is poorly equipped to deal with modern developments in the visual arts. Secondly, the pervasive effect of rhetorical discourse appears to have made it particularly difficult for copyright law to strike a meaningful balance between protecting creativity and permitting its use in further creative works. Thirdly, just when rhetorical discourse might have been useful in identifying the significance and materiality of the unique one-off work of visual art, copyright law chooses to ignore its implications
Solvothermal nanoYAG synthesis: Mechanism and particle growth kinetics
This paper was accepted for publication in the journal Journal of Supercritical Fluids and the definitive published version is available at http://dx.doi.org/10.1016/j.supflu.2015.09.031NanoYAG particles with spherical morphology have been synthesised using a solvothermal method; a structure sensitive reaction, where the chemical reaction and the particle growth kinetics are interdependent. It has been observed that the primary YAG particles agglomerated into ∼30 nm clusters via a self-assembled Ostwald ripening process along (2 1 1) planes, separated by a distance of ∼0.49 nm, at 270 °C and 2.0 MPa for 2 h. These nanoclusters coalesced into single nanoparticles of ∼30 nm in size and exhibited a smaller inter planar distance of ∼0.26 nm, corresponding to the (4 2 0) planes, when synthesized at 300 °C and 8.5 MPa for 2 h. in addition, the solvent 1,4-butanediol transformed into 1,4-diacetoxybutane, this will have undergone esterification by reacting with the terminal acetate groups cleaved from the precursor, yttrium acetate. The proposed mechanism based on the analytical evidence suggests that a complete dissolution of precursors facilitated the structural re-arrangement of atoms within the planes and lead to a significantly higher degree of crystallinity. Moreover, once the particles with (4 2 0) planes had formed, they were no longer involved in facile coalescence along their preferential planes due to their lower interfacial energy compared to the (2 1 1) planes. This led to control of the particle morphology and with little agglomeration occurring in the final nanopowder
Temperature dependent CO2 behavior in microporous 1-D channels of a metal-organic framework with multiple interaction sites
The MOF with the encapsulated CO2 molecule shows that the CO2 molecule is ligated to the unsaturated Cu(II) sites in the cage using its Lewis basic oxygen atom via an angular eta(1)-(O-A) coordination mode and also interacts with Lewis basic nitrogen atoms of the tetrazole ligands using its Lewis acidic carbon atom. Temperature dependent structure analyses indicate the simultaneous weakening of both interactions as temperature increases. Infrared spectroscopy of the MOF confirmed that the CO2 interaction with the framework is temperature dependent. The strength of the interaction is correlated to the separation of the two bending peaks of the bound CO2 rather than the frequency shift of the asymmetric stretching peak from that of free CO2. The encapsulated CO2 in the cage is weakly interacting with the framework at around ambient temperatures and can have proper orientation for wiggling out of the cage through the narrow portals so that the reversible uptake can take place. On the other hand, the CO2 in the cage is restrained at a specific orientation at 195 K since it interacts with the framework strong enough using the multiple interaction sites so that adsorption process is slightly restricted and desorption process is almost clogged.ope
Micro‐Raman spectroscopy of indentation induced phase transformation in nanozirconia ceramics
This article was published in the journal Advances in Applied Ceramics, published by Maney: http://maney.co.uk/Micro-Raman spectroscopy has been employed as an effective technique to determine the phase transformations in nanostructured yttria stabilised zirconia (YSZ) ceramics with different yttria content. Samples have been prepared with varying mean grain sizes by a slip casting route followed by a microwave assisted two-step sintering cycle starting with aqueous nanozirconia suspensions. Indents were generated using a Vickers pyramidal indenter at different loads and the resulting phase transformations were mapped using micro-Raman spectroscopy. The results were compared to those of a commercial submicron 3YSZ. The amount of transformation was found to be much lower for nanozirconia compared to the submicron zirconia with similar yttria content
Alkaline-earth phosphonate MOFs with reversible hydration-dependent fluorescence
A new rigid tritopic phosphonic ligand, 2,4,6-tris(4-phosphonophenyl)pyridine (H6L), was synthesized and used to assemble isostructural barium (1) and strontium (2) phosphonate metal organic frameworks that exhibit fully reversible and selective water-dependent fluorescence red-shift at room temperature
High pressure studies on AgI-Ag<SUB>2</SUB>O-MoO<SUB>3</SUB> glasses
The effect of pressure on the conductivity of AgI-Ag2O-MoO3 glasses has been
reexamined. A conductivity maximum is observed around 0.7 GPa. No variation of the sample temperature is noted under
pressure. The results are found to agree well with the cluster-tissue model
Supramolecular binding and separation of hydrocarbons within a functionalised porous metal-organic framework
Supramolecular interactions are fundamental to host-guest binding in chemical and biological processes. Direct visualisation of such supramolecular interactions within host-guest systems is extremely challenging but crucial for the understanding of their function. We report a comprehensive study combining neutron scattering with synchrotron X-ray and neutron diffraction, coupled with computational modelling, to define the detailed binding at a molecular level of acetylene, ethylene and ethane within the porous host NOTT-300. This study reveals the simultaneous and cooperative hydrogen-bonding, π···π stacking interactions and inter-molecular dipole interactions in the binding of acetylene and ethylene to give up to twelve individual weak supramolecular interactions aligned within the host to form an optimal geometry for intelligent, selective binding of hydrocarbons. We also report, for the first time, the cooperative binding of a mixture of acetylene and ethylene within the porous host together with the corresponding breakthrough experiment and analysis of mixed gas adsorption isotherms
Biological evaluation of zirconia toughened apatitic composite implant
A biological study is reported where implants of β- TCP/ t- ZrO2 has been examined in rabbit mandibles. The composite is found to be fully biocompatible and evidence of good osteoconduction and tissue ingress has been noticed
Synthesis and spark plasma sintering of sub-micron HfB<sub>2</sub>:effect of various carbon sources
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