Sir Robert Hadfield Building

Sheffield, United Kingdom

Sir Robert Hadfield Building

Sheffield, United Kingdom

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Freeman C.L.,Sir Robert Hadfield Building | Harding J.H.,Sir Robert Hadfield Building | Quigley D.,University of Warwick | Rodger P.M.,University of Warwick
Physical Chemistry Chemical Physics | Year: 2012

Simulations using classical molecular dynamics are reported on the binding of the protein Ovocleidin-17 to calcite stepped surfaces. vicinal surfaces ({31.8} and {31.16}) are used to obtain acute and obtuse steps. The simulations demonstrate that binding is greater at the obtuse step. A range of analytical methods is used to show the importance of surface and local water structure for protein binding. We discuss the general features of molecular binding in the light of these results. Our analysis shows that it is unlikely that Ovocleidin-17 is important in controlling crystal morphology; its main role is likely to be in controlling calcite nucleation. © 2012 the Owner Societies.


Freeman C.L.,Sir Robert Hadfield Building | Harding J.H.,Sir Robert Hadfield Building | Quigley D.,University of Warwick | Rodger P.M.,University of Warwick
Physical Chemistry Chemical Physics | Year: 2015

Atomistic molecular dynamics simulations of dehydrated amorphous calcium carbonate interacting with the protein ovocleidin-17 are presented. These simulations demonstrate that the amorphisation of the calcium carbonate surface removes water structure from the surface. This reduction of structure allows the protein to bind with many residues, unlike on crystalline surfaces where binding is strongest when only a few residues are attached to the surface. Basic residues are observed to dominate the binding interactions. The implications for protein control over crystallisation are discussed. This journal is © the Owner Societies 2015.


Scamans G.M.,Innoval Technology | Frolish M.F.,Sir Robert Hadfield Building | Rainforth W.M.,Sir Robert Hadfield Building | Zhou Z.,Sir Robert Hadfield Building | And 3 more authors.
Surface and Interface Analysis | Year: 2010

In 1996, it was found that the Beilby layer on rolled aluminium sheet could be imaged in the transmission electron microscope (TEM) on ultramicrotomed cross sections of the sheet surface. Following from this observation, we have examined Beilby layers on all types of aluminium surfaces that have been subject to high shear processing treatments such as rolling, grinding or machining. The layers are microcrystalline rather than amorphous, and they strongly influence properties like corrosion resistance and reflectance. Preferential precipitation in these deformed surface layers results in their electrochemical activation and it is responsible for the development of underfilm corrosion in most architectural and automotive alloys. More recently, it has been possible to directly image Beilby layers on ultramicrotomed stubs using the new generation of low kilovoltage high-resolution scanning electron microscopes and to carry out high-resolution TEM of sections cut from precisely located surface features. The paper presents an overview of all the recent investigations of high shear induced Beilby layers on aluminium alloys and discusses their control of surface properties. Copyright ©2010 John Wiley & Sons, Ltd.


Hata S.,Kyushu University | Miyazaki H.,Mel Build | Miyazaki S.,FEI Company Japan Ltd. | Mitsuhara M.,Kyushu University | And 9 more authors.
Ultramicroscopy | Year: 2011

Electron tomography requires a wide angular range of specimen-tilt for a reliable three-dimensional (3D) reconstruction. Although specimen holders are commercially available for tomography, they have several limitations, including tilting capability in only one or two axes at most, e.g. tilt-rotate. For amorphous specimens, the image contrast depends on mass and thickness only and the single-tilt holder is adequate for most tomographic image acquisitions. On the other hand, for crystalline materials where image contrast is strongly dependent on diffraction conditions, current commercially available tomography holders are inadequate, because they lack tilt capability in all three orthogonal axes needed to maintain a constant diffraction condition over the whole tilt range. We have developed a high-angle triple-axis (HATA) tomography specimen holder capable of high-angle tilting for the primary horizontal axis with tilting capability in the other (orthogonal) horizontal and vertical axes. This allows the user to trim the specimen tilt to obtain the desired diffraction condition over the whole tilt range of the tomography series. To demonstrate its capabilities, we have used this triple-axis tomography holder with a dual-axis tilt series (the specimen was rotated by 90° ex-situ between series) to obtain tomographic reconstructions of dislocation arrangements in plastically deformed austenitic steel foils. © 2011 Elsevier B.V.


Rahimi S.,University of Strathclyde | Wynne B.P.,Sir Robert Hadfield Building | Baker T.N.,University of Strathclyde
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2016

The evolution of microstructure and crystallographic texture has been investigated in double-sided friction stir welded microalloyed steel, using electron backscatter diffraction (EBSD). The microstructure analyses show that the center of stirred zone reached a temperature between Ac1 and Ac3 during FSW, resulting in a dual-phase austenitic/ ferritic microstructure. The temperatures in the thermo-mechanically affected zone and the overlapped area between the first and second weld pass did not exceed the Ac1. The shear generated by the rotation probe occurs in austenitic/ferritic phase field where the austenite portion of the microstructure is transformed to a bainitic ferrite, on cooling. Analysis of crystallographic textures with regard to shear flow lines generated by the probe tool shows the dominance of simple shear components across the whole weld. The austenite texture at Ac1 - Ac3 is dominated by the B(Formula presented.) and (Formula presented.)(Formula presented.) simple shear texture components, where the bainite phase textures formed on cooling were inherited from the shear textures of the austenite phase with relatively strong variant selection. The ferrite portion of the stirred zone and the ferrites in the thermo-mechanically affected zones and the overlapped area underwent shear deformation with textures dominated by the D1(Formula presented.) and D2(Formula presented.) simple shear texture components. The formation of ultrafine equiaxed ferrite with submicron grain size has been observed in the overlapped area between the first and second weld pass. This is due to continuous dynamic strain-induced recrystallization as a result of simultaneous severe shear deformation and drastic undercooling. © 2016 The Minerals, Metals & Materials Society and ASM International


Butler K.T.,Sir Robert Hadfield Building | Lamers M.P.W.E.,Energy Research Center of the Netherlands | Weeber A.W.,Energy Research Center of the Netherlands | Harding J.H.,Sir Robert Hadfield Building
Journal of Applied Physics | Year: 2011

In this paper we present molecular dynamics simulations of silicon nitride, both in bulk and as an interface to crystalline silicon. We investigate, in particular, the bonding structure of the silicon nitride and analyze the simulations to search for defective geometries which have been identified as potential charge carrier traps when silicon nitride forms an interface with silicon semiconductors. The simulations reveal how the bonding patterns in silicon nitride are dependent upon the stoichiometry of the system. Furthermore we demonstrate how having an interphase, where the nitrogen content in silicon gradually reduces toward pure silicon across a boundary region, as opposed to an interface where there is an abrupt drop in nitrogen concentration at the boundary, can result in significantly different numbers of certain important carrier trap. © 2011 American Institute of Physics.


Lin L.,Sir Robert Hadfield Building | Zhang S.,Sir Robert Hadfield Building | Zhang S.,University of Exeter
Chemical Communications | Year: 2012

We have developed an effective method to exfoliate and disintegrate multi-walled carbon nanotubes and graphite flakes. With this technique, high yield production of luminescent graphene quantum dots with high quantum yield and low oxidization can be achieved. © The Royal Society of Chemistry 2012.


Stennett M.C.,Sir Robert Hadfield Building | Pinnock I.J.,Sir Robert Hadfield Building | Hyatt N.C.,Sir Robert Hadfield Building
Materials Research Society Symposium Proceedings | Year: 2012

Microwave dielectric heating was utilized to synthesize potential host phases for halide radioisotopes. Synthesis of Pb5(VO 4)3I was successfully achieved, without the use of a sealed container, using a modified domestic microwave oven (DMO) operating at 2.45 GHz. Rapid synthesis of Pb5(VO4)3X (X = F, Cl, Br) was also achieved using a commercially available microwave muffle furnace, also operating at 2.45 GHz. The combination of rapid heating rate and inverse temperature profile characteristic of microwave heating was found to promote formation of the target phases whilst retarding the volatilization of the halide species. Pb5(VO4)3I ceramic bodies produced in the DMO exhibited a heterogeneous zoned microstructure, whereas Pb5(VO4)3X phases with X = F, Cl, and Br fabricated in the microwave muffle furnace were dimensionally uniform suggesting this could be a promising route to fabricating single phase, dense halide containing ceramics. © 2012 Materials Research Society.


PubMed | Sir Robert Hadfield Building
Type: Journal Article | Journal: Physical chemistry chemical physics : PCCP | Year: 2015

Atomistic molecular dynamics simulations of dehydrated amorphous calcium carbonate interacting with the protein ovocleidin-17 are presented. These simulations demonstrate that the amorphisation of the calcium carbonate surface removes water structure from the surface. This reduction of structure allows the protein to bind with many residues, unlike on crystalline surfaces where binding is strongest when only a few residues are attached to the surface. Basic residues are observed to dominate the binding interactions. The implications for protein control over crystallisation are discussed.


PubMed | Sir Robert Hadfield Building
Type: Journal Article | Journal: Physical chemistry chemical physics : PCCP | Year: 2012

Simulations using classical molecular dynamics are reported on the binding of the protein Ovocleidin-17 to calcite stepped surfaces. vicinal surfaces ({31.8} and {31.16}) are used to obtain acute and obtuse steps. The simulations demonstrate that binding is greater at the obtuse step. A range of analytical methods is used to show the importance of surface and local water structure for protein binding. We discuss the general features of molecular binding in the light of these results. Our analysis shows that it is unlikely that Ovocleidin-17 is important in controlling crystal morphology; its main role is likely to be in controlling calcite nucleation.

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