Broadband and low loss high refractive index metamaterials in the microwave regime

Copyright © 2013 American Institute of PhysicsA broadband, low-loss, isotropic, high refractive index metamaterial comprising an array of close-packed cubic elements of cross-linked square metal plates is demonstrated in the microwave regime. The structuring of the cubic elements reduces the diamagnetic response exhibited by arrays of solid metal cubes, whilst maintaining the strongly enhanced permittivity arising from capacitative coupling between adjacent metal elements. The corresponding increase in refractive index can be tailored through appropriate structuring of the faces and/or spacing of the cubes

Reverse Alignment - Understanding Centerline Measurement.

Tutorialpg. 189-196Shaft alignment is a key factor in reducing vibrations and increasing reliability in rotating equipment. The most popular method of measurement is "reverse alignment." This method is often considered so complicated that many users have developed step by step worksheets, plotting boards, programmable calculators, and computer-aided laser devices that can guide the aligner through the procedure without a real understanding of the fundamentals of alignment. A need for a good understanding of the reverse method of measurement prompted this presentation. The focus herein is to show how misalignment affects the rotor's behavior. Using a back to basics graphical method, it is shown how to visualize the shaft center lines that enable the aligner to use logic for the easiest and best move. Calculation of thermal growth and how to select an allowable tolerance is also discussed. Hot alignment is presented by showing different online monitoring systems as well as how to misalign cold so that the shafts will be colinear during operation. An alignment trainer is used to demonstrate how an actual alignment is made

Clinical effectiveness and cost-effectiveness of open and arthroscopic rotator cuff repair [the UK Rotator Cuff Surgery (UKUFF) randomised trial]

Peer reviewedPublisher PD

The use of decellularised animal tissue to study disseminating cancer cells

Since the establishment of cell culture, common practice has been to grow adherent cells in 2D monolayers. Although cells behave completely differently when grown under these artificial conditions, the ease of 2D culturing has meant that this practice still prevails, and adopting conditions that more closely reflect the natural microenvironment has been met with substantial inertia. The alternative, animal models that mimic natural human physiology, are less accessible, strictly regulated and require licences and expensive facilities. Although transition from 2D to 3D cell culturing is gathering momentum, there is a clear need for alternative culturing methods that more closely resemble in vivo conditions. Here, we show that decellularised organs gleaned from discarded animal carcasses are ideal biomimetic scaffolds to support secondary tumour initiation in vitro. Further, we describe how to decellularise tissue and perform basic histochemistry and immunofluorescence procedures for cell and matrix detection. Cancer cell behaviour on this matrix is followed by way of an example. Because integration into the traditional work flow is easy and inexpensive, we hope this article will encourage other researchers to adopt this approach

Chapter 13: Permian–Triassic felsic tuffs in South Island, New Zealand: significance for oceanic and active continental margin subduction

Major-element oxide variation plots for the Brook Street Terrane. (a) Fe₂O₃ v. SiO₂; (b) MnO v. SiO₂; (c) MgO v. SiO₂; (d) TiO₂ v. Al₂O₃; (e) TiO₂ v. MgO; (f) Fe₂O₃ v. MgO; (g) MnO v. MgO; (h) CaO v. MgO; (i) K₂O v. MgO. See text and the Supplementary field and petrographic information for explanation

Microwave Surface Waves on Metasurfaces with Planar Discontinuities

The work presented within this thesis details the experimental investigation of the surface waves supported on metasurfaces. Particular attention has been given to the reflection of these surface waves from planar discontinuities associated with these metasurfaces. Various experimental techniques have been developed throughout this work to characterise surface wave supporting metasurfaces. These include a new technique for measuring the dispersion of surface waves supported on metasurfaces, characterisation of the near-field associated with the surface waves, a device for launching planar phase front surface waves and finally a technique for measuring the surface wave reflection coefficient. The dispersion of surface waves on a square array of square cross-section metal pillars has been fully characterised and compared to FEM modelling. The results show that a family of surface waves may be supported by pillar or crossed slit structures rather than just holes even though there is now no lowest cut-off frequency. A family of TM surface modes have been shown to exist with dispersions which asymptote to frequencies defined by the pillar heights (slit depth) and the refractive index of the material filling the slits. Primarily this work focussed on the surface wave properties associated with a square array of square metal patches on a dielectric coated ground plane and a Sievenpiper `mushroom' metasurface. The amplitude reflection coefficient of these surface waves has been studied for three distinct systems: Firstly for surface waves incident upon the termination of a these metasurfaces to free space, secondly for surface waves incident upon the interface between a dielectric coated and uncoated metasurface and thirdly for surface waves incident on the boundary between two metaurfaces. The reflection coefficient of surface waves incident upon the termination of the metasurface to free space is found to increase significantly with the confinement of the surface mode. This confinement, and therefore the form of the reflection coefficient, is significantly different for the two metasurfaces considered due to their dispersions. This increase in the reflection coefficient is caused by both the momentum mismatch of the surface wave compared to the freely propagating modes and the different field distributions of the two modes. The reflection coefficient of surface waves incident upon the boundary between a coated and uncoated metasurface has been experimentally characterised for the metal patch array and Sievenpiper `mushroom' metasurfaces. It is shown that the addition of a thin, significantly subwavelength, dielectric overlayer onto the metasurface vastly perturbs the surface wave dispersion. The reflection coefficient of the surface waves is found to depend on the dispersion of the mode supported on the coated and uncoated metasurface and the overlayer thickness. Most noticeably the thickness of the overlayer, by comparison to the surface wave decay length, has a significant effect on scattering to free space associated with the surface wave reflection. The final system considered was designed to investigate the impedance approximation, often used to describe metasurfaces, and found it to be an incomplete description of the surface waves supported on the metasurfaces used within this study. In the impedance approximation the two surfaces considered are said to be `impedance matched` at certain frequencies. It is demonstrated that the failure of the impedance approximation to accurately describe this system is due to the behaviour of the electric field within the metasurfaces. These are not analytically described in the impedance approximation and are required for an accurate description of the surface waves supported on these metasurfaces.EPSRCBAE System

Chapter 15: Construction of a Paleozoic–Mesozoic accretionary orogen along the active continental margin of SE Gondwana (South Island, New Zealand): summary and overview

Petrographic features of semi-schists from East Bald Hill (northern Southland). (<b>a</b>) Weakly cleaved volcaniclastic sandstone, with relict elongated clasts of feldspar-phyric extrusive rock in a pelitic matrix; sample N13.134, equivalent of the West Burn Semischist, Caples Terrane; upper northern slopes of East Bald Hill, northern Southland, S45 35790 E 168 16473, viewed under plane polarized light (PPL). (<b>b</b>) Subangular grain of monocrystalline (volcanic) quartz, with strain shadows in sheared volcanogenic matrix; sample N13.137, equivalent of the West Burn Semischist, Caples Terrane; upper northern slopes of East Bald Hill, northern Southland, S45 35523 E 168 16531, viewed under PPL. (<b>c</b>) Volcaniclastic microconglomerate; altered basaltic clast within sheared (relatively incompetent) volcaniclastic fine-grained sandstone/phyllite; sample N13.135, equivalent of the West Burn Semischist, Caples Terrane; upper northern slopes of East Bald Hill, Caples Terrane, S45 35790 E 168 16473, viewed under PPL. (<b>d</b>) Polyphase shearing and folding in partially recrystallized volcaniclastic sandstone/microconglomerate. Note truncation of inclined shear fabric by later-stage sub-horizontal shear fabric; sample N13.135, equivalent of the West Burn Semischist, Caples Terrane; NW upper slope of East Bald Hill, northern Southland; S45 35790 E 168 16473, viewed under PPL. (<b>e</b>) Weakly cleaved volcaniclastic sandstone cut by veins (chlorite-rich) that were later folded; sample N13.135, equivalent of the West Burn Semischist, Caples Terrane; upper northern slopes of East Bald Hill, northern Southland, S45 35790 E 168 16473, viewed under PPL. (<b>f</b>) As above, but showing asymmetrical (top-right) microfolds, viewed under PPL

E-cadherin can limit the transforming properties of activating β-catenin mutations

Wnt pathway deregulation is a common characteristic of many cancers. But only Colorectal Cancer predominantly harbours mutations in APC, whereas other cancer types (hepatocellular carcinoma, solid pseudopapillary tumours of pancreas) have activating mutations in β-catenin (CTNNB1). We have compared the dynamics and the potency of β-catenin mutations in vivo. Within the murine small intestine (SI), an activating mutation of β-catenin took much longer to achieve a Wnt deregulation and acquire a crypt-progenitor-cell (CPC) phenotype than Apc or Gsk3 loss. Within the colon, a single activating mutation of β-catenin was unable to drive Wnt deregulation or induce the CPC phenotype. This ability of β-catenin mutation to differentially transform the SI versus the colon correlated with significantly higher expression of the β-catenin binding partner E-cadherin. This increased expression is associated with a higher number of E-cadherin:β-catenin complexes at the membrane. Reduction of E-cadherin synergised with an activating mutation of β-catenin so there was now a rapid CPC phenotype within the colon and SI. Thus there is a threshold of β-catenin that is required to drive transformation and E-cadherin can act as a buffer to prevent β-catenin accumulation