966 resultados para LSF walls


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To determine if calcium scores (CS) could act as a more effective gatekeeper than Diamond Forrester (DF) in the assessment of patients with suspected coronary artery disease (CAD). A sub-study of the Cardiac CT for the Assessment of Chest Pain and Plaque (CAPP) study, a randomised control trial evaluating the cost-effectiveness of cardiac CT in symptomatic patients with stable chest pain. Stable pain was defined as troponin negative pain without symptoms of unstable angina. 250 patients undergoing cardiac CT had both DF scores and CS calculated, with the accuracy of both evaluated against CT coronary angiogram. Criteria given in UK national guidelines were compared. Of the 250 patients, 4 withdrew. 140 (57 %) patients were male. The mean DF was 47.8 and mean CS 172.5. Of the 144 patients with non-anginal pain 19.4 % had significant disease (>50 % stenosis). In general the DF over estimated the presence of CAD whereas the CS reclassified patients to lower risk groups, with 91 in the high risk DF category compared to 26 in the CS. Both receiver operating curve and McNemar Bowker test analysis suggested the DF was less accurate in the prediction of CAD compared to CS [Formula: see text] Projected downstream investigations were also calculated, with the cost per number of significant stenoses identified cheaper with the CS criteria. Patients with suspected stable CAD are more accurately risk stratified by CS compared to the traditional DF. CS was more successful in the prediction of significant stenosis and appears to be more effective at targeting clinical resources to those patients that are in need of them.

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Epitaxial tetragonal 425 and 611 nm thick Pb(ZrTi)O (PZT) films are deposited by pulsed laser deposition on SrRuO-coated (100) SrTiO 24° tilt angle bicrystal substrates to create a single PZT grain boundary with a well-defined orientation. On either side of the bicrystal boundary, the films show square hysteresis loops and have dielectric permittivities of 456 and 576, with loss tangents of 0.010 and 0.015, respectively. Using piezoresponse force microscopy (PFM), a decrease in the nonlinear piezoelectric response is observed in the vicinity (720-820 nm) of the grain boundary. This region represents the width over which the extrinsic contributions to the piezoelectric response (e.g., those associated with the domain density/configuration and/or the domain wall mobility) are influenced by the presence of the grain boundary. Transmission electron microscope (TEM) images collected near and far from the grain boundary indicate a strong preference for (101)/(1-01) type domain walls at the grain boundary, whereas (011)/(01-1) and (101)/(1-01) are observed away from this region. It is proposed that the elastic strain field at the grain boundary interacts with the ferro-electric/elastic domain structure, stabilizing (101)/(1-01) rather than (011)/(01-1) type domain walls, which inhibits domain wall motion under applied field and decreases non-linearity. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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Pressure myography studies have played a crucial role in our understanding of vascular physiology and pathophysiology. Such studies depend upon the reliable measurement of changes in the diameter of isolated vessel segments over time. Although several software packages are available to carry out such measurements on small arteries and veins, no such software exists to study smaller vessels (<50 µm in diameter). We provide here a new, freely available open-source algorithm, MyoTracker, to measure and track changes in the diameter of small isolated retinal arterioles. The program has been developed as an ImageJ plug-in and uses a combination of cost analysis and edge enhancement to detect the vessel walls. In tests performed on a dataset of 102 images, automatic measurements were found to be comparable to those of manual ones. The program was also able to track both fast and slow constrictions and dilations during intraluminal pressure changes and following application of several drugs. Variability in automated measurements during analysis of videos and processing times were also investigated and are reported. MyoTracker is a new software to assist during pressure myography experiments on small isolated retinal arterioles. It provides fast and accurate measurements with low levels of noise and works with both individual images and videos. Although the program was developed to work with small arterioles, it is also capable of tracking the walls of other types of microvessels, including venules and capillaries. It also works well with larger arteries, and therefore may provide an alternative to other packages developed for larger vessels when its features are considered advantageous.

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The 71 degrees stripe domain patterns of epitaxial BiFeO3 thin films are frequently being explored to achieve new functional properties, dissimilar from the BiFeO3 bulk properties. We show that in-plane switching and out-of-plane switching of these domains behave very differently. In the in-plane configuration the domains are very stable, whereas in the out-of-plane configuration the domains change their size and patterns, depending on the applied switching voltage frequency.

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For The Map of Watchful Architecture I only concerned myself with defensive architecture along the Border. As the map followed a border it came out as a wavy line of points. This was largely artificial, I only charted architecture within the Border corridor, but was not entirely artificial. That linear landscape has long been staked-out by the regularity of certain kinds of architecture. The 1st/2nd century Black Pig’s Dyke and Dorsey correspond with today’s Border. The concentration of souterrains in north Louth indicate that it may have been a volatile interface zone in later centuries. In 1618 Londonderry and its walls were built. Further north and two centuries later, Martello Towers were constructed to watch over Lough Foyle. During the Second World War pillboxes and observation posts were manned along the Border, close to what was now an international frontier. Then came the Operation Banner installations built during The Troubles. All this adds up to be one of the longest unbroken traditions of defensive architecture anywhere in Western Europe, a tradition some thought finally broken as the last of the Operation Banner towers were de-installed in 2007. But, take a bus south across the Border and you will often be pulled over by the Garda Síochána. They ID check the passengers in an attempt to stop illegal immigration via the UK. What about illegal immigrants who walk through the fields or along quiet lanes? They will have understood the Border is not really how it seems on most maps. It is not a solid line, it is a row of points.

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Soils and saprolites developed from interbedded shales and limestones of the Conasauga Group are widespread in the Valley and Ridge Province of East Tennessee. Thin sections from four soil profiles were examined by petrographic and scanning electron microscopy including backscatter electron and energy-dispersive X-ray analyses. Iron and manganese released by weathering had migrated differentially downward and precipitated as crystalline and noncrystalline oxides. Oxides were observed as nodules, granular particulates, pore fillings, and coatings on other minerals, packing voids, vesicles, channels, and chambers. Iron oxides formed predominantly as coatings on packing-void walls and on laminated clays in vesicles and channels. Manganese oxides occurred as an early replacement phase of packing voids and of fracture-filling carbonate minerals. Iron oxides were dominant in moderately well-drained and oxidized horizons of the soil solum, whereas manganese oxides were abundant in the oxidized and moderately leached saprolite zone where the water table fluctuates seasonally. Therefore, a manganese enrichment zone, on a bulk soil basis, occurred generally below the iron oxide zone in the soil profile. Such differential migration and accumulation of iron and manganese have been controlled by localized soil microenvironments. Micromorphologic features observed in this study are important in land-use evaluation for hazardous waste disposal. © 1990.

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Abstract. The possibility of using pumice aggregates for concrete in structural applications is discussed. In particular, the mix design of lightweight concrete for the manufacturing masonry units having proper strength, is discussed. Moreover, the design of the unit shape according to the technical code requirements and making it possible to arrange reinforcing steel bars is described. Reinforced bearing masonry walls, made with the concrete units in question, were manufactured and tests on the panels and on the designed units were carried out. For comparison, tests on concrete units and structural elements were carried out after the substitution of pumice aggregates with ordinary lightweight aggregates, proving that pumice can be considered an alternative to them. Sommario. L’uso della pomice come inerte per il confezionamento di calcestruzzo è poco diffuso sebbene essa sia stata usata già in antiche costruzioni come il Pantheon in Roma. In questo studio si affronta la possibilità di realizzare blocchi in calcestruzzo alleggerito con granuli di pomice. I blocchi, progettati e realizzati secondo le indicazioni normative correnti, sono stati usati per realizzare pannelli murari armati da sottoporre a carichi ciclici orizzontali. I risultati ottenuti, messi a confronto con quelli di pannelli realizzati con blocchi in cls alleggerito con argilla espansa, hanno mostrato la possibilità di utilizzare la pomice come validissima alternativa all’argilla espansa.

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Abstract. The possibility of using pumice aggregates for concrete in structural applications is discussed. In particular, the mix design of lightweight concrete for the manufacturing masonry units having proper strength, is discussed. Moreover, the design of the unit shape according to the technical code requirements and making it possible to arrange reinforcing steel bars is described. Reinforced bearing masonry walls, made with the concrete units in question, were manufactured and tests on the panels and on the designed units were carried out. For comparison, tests on concrete units and structural elements were carried out after the substitution of pumice aggregates with ordinary lightweight aggregates, proving that pumice can be considered an alternative to them. Sommario. L’uso della pomice come inerte per il confezionamento di calcestruzzo è poco diffuso sebbene essa sia stata usata già in antiche costruzioni come il Pantheon in Roma. In questo studio si affronta la possibilità di realizzare blocchi in calcestruzzo alleggerito con granuli di pomice. I blocchi, progettati e realizzati secondo le indicazioni normative correnti, sono stati usati per realizzare pannelli murari armati da sottoporre a carichi ciclici orizzontali. I risultati ottenuti, messi a confronto con quelli di pannelli realizzati con blocchi in cls alleggerito con argilla espansa, hanno mostrato la possibilità di utilizzare la pomice come validissima alternativa all’argilla espansa.

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The Parker Morris report of 1961 attempted, through the application of scientific principles, to define the minimum living space standards needed to accommodate household activities. But while early modernist research into ideas of existenzminimum were the work of avant-garde architects and thinkers, this report was commissioned by the British State. This normalization of scientific enquiry into space can be considered not only a response to new conditions in the mass production of housing – economies of scale, prefabrication, system-building and modular coordination – but also to the post-war boom in consumer goods. The domestic interior was assigned a key role as a privileged site of mass consumption as the production and micro-management of space in Britain became integral to the development of a planned national economy underpinned by Fordist principles. The apparently placeless and scale-less diagrams executed by Gordon Cullen to illustrate Parker Morris emblematize these relationships. Walls dissolve as space flows from inside to outside in a homogenized and ephemeral landscape whose limits are perhaps only the boundaries of the nation state and the circuits of capital.

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The methane solubility in five pure electrolyte solvents and one binary solvent mixture for lithium ion batteries – such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC) and the (50:50 wt%) mixture of EC:DMC was studied experimentally at pressures close to atmospheric and as a function of temperature between (280 and 343) K by using an isochoric saturation technique. The effect of the selected anions of a lithium salt LiX (X = hexafluorophosphate,

&lt;img height="16" border="0" style="vertical-align:bottom" width="27" alt="View the MathML source" title="View the MathML source" src="http://origin-ars.els-cdn.com/content/image/1-s2.0-S0021961414002146-si1.gif"&gt;PF6-; tris(pentafluoroethane)trifluorurophosphate, FAP; bis(trifluoromethylsulfonyl)imide, TFSI) on the methane solubility in electrolytes for lithium ion batteries was then investigated using a model electrolyte based on the binary mixture of EC:DMC (50:50 wt%) + 1 mol · dm−3 of lithium salt in the same temperature and pressure ranges. Based on experimental solubility data, the Henry’s law constant of the methane in these solutions were then deduced and compared together and with those predicted by using COSMO-RS methodology within COSMOthermX software. From this study, it appears that the methane solubility in each pure solvent decreases with the temperature and increases in the following order: EC < PC < EC:EMC (50:50 wt%) < DMC < EMC < DEC, showing that this increases with the van der Walls force in solution. Additionally, in all investigated EC:DMC (50:50 wt%) + 1 mol · dm−3 of lithium salt electrolytes, the methane solubility decreases also with the temperature and the methane solubility is higher in the electrolyte containing the LiFAP salt, followed by that based on the LiTFSI one. From the variation of the Henry’s law constants with the temperature, the partial molar thermodynamic functions of solvation, such as the standard Gibbs free energy, the enthalpy, and the entropy where then calculated, as well as the mixing enthalpy of the solvent with methane in its hypothetical liquid state. Finally, the effect of the gas structure on their solubility in selected solutions was discussed by comparing methane solubility data reported in the present work with carbon dioxide solubility data available in the same solvents or mixtures to discern the more harmful gas generated during the degradation of the electrolyte, which limits the battery lifetime.

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Chemically ordered B2 FeRh exhibits a remarkable antiferromagnetic-ferromagnetic phase transition that is first order. It thus shows phase coexistence, usually by proceeding though nucleation at random defect sites followed by propagation of phase boundary domain walls. The transition occurs at a temperature that can be varied by doping other metals onto the Rh site. We have taken advantage of this to yield control over the transition process by preparing an epilayer with oppositely directed doping gradients of Pd and Ir throughout its height, yielding a gradual transition that occurs between 350 K and 500 K. As the sample is heated, a horizontal antiferromagnetic-ferromagnetic phase boundary domain wall moves gradually up through the layer, its position controlled by the temperature. This mobile magnetic domain wall affects the magnetisation and resistivity of the layer in a way that can be controlled, and hence exploited, for novel device applications.

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The buried and semi-buried bunker, bulwark since the early eighteenth century against increasingly sophisticated forms of ordnance, emerged in increasing number in Europe throughout the twentieth century across a series of scales from the household Anderson shelter to the vast infrastructural works of the Maginot and Siegfried lines, or the Atlantic Wall. Its latest proliferation took place during the Cold War. From these perspectives, it is as emblematic of modernity as the department store, the great exhibition, the skyscraper or the machine-inspired domestic space advocated by Le Corbusier. It also represents the obverse, or perhaps a parodic iteration, of the preoccupations of early architectural modernism: a vast underground international style, cast in millions of tons of thick, reinforced concrete retaining walls, whose spatial relationship to the landscape above was strictly mediated through the periscope, the loop-hole, the range finder and the strategic necessity to both resist and facilitate the technologies and scopic regimes of weaponry. Embarking from Bunker Archaeology, this paper critically uncoils Paul Virillo’s observation, that once physically eclipsed in its topographical and technical settings, the bunker’s efficacy would mutate to other domains, retaining and remaking its meaning in another topology during the Cold War. ‘The essence of the new fortress’ he writes ‘is elsewhere, underfoot, invisible from here on in’. Shaped by this impulse, this paper seeks to render visible the bunker’s significance in a wider milieu and, in doing so, excavate some of the relationships between the physical artefact, its implications and its enduring metaphorical and perceptual ghosts.

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For over a decade, controlling domain wall injection, motion and annihilation along nanowires has been the preserve of the nanomagnetics research community. Revolutionary technologies have resulted, like race-track memory and domain wall logic. Until recently, equivalent research in analogous ferroic materials did not seem important. However, with the discovery of sheet conduction, the control of domain walls in ferroelectrics has become vital for the future of what has been termed “domain wall electronics”. Here we report the creation of a ferroelectric domain wall diode, which allows a single direction of motion for all domain walls, irrespective of their polarity, under a series of alternating electric field pulses. The diode’s saw-tooth morphology is central to its function. Domain walls can move readily in the direction in which thickness increases gradually, but are prevented from moving in the other direction by the sudden thickness increase at the saw-tooth edge.

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A conjugate heat transfer (CHT) method was used to perform the aerothermal analysis of an internally cooled turbine vane, and was validated against experimental and empirical data.
Firstly, validation of the method with regard to internal cooling was done by reproducing heat transfer test data in a channel with pin fin heat augmenters, under steady constant wall temperature. The computed Nusselt numbers for the two tested configurations (full length circular pin fins attached to both walls and partial pin fins attached to one wall only) showed good agreement with the measurements. Sensitivity to mesh density was evaluated under this simplified case in order to establish mesh requirements for the analysis of the full component.
Secondly, the CHT method was applied onto a turbine vane test case from an actual engine. The predicted vane airfoil metal temperature was compared to the measured thermal paint data and the in-house empirical predictions. The CHT results agreed well with the thermal paint data and showed better prediction than the current empirical modeling approach.

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Mollusk shells are frequently radiocarbon dated and provide reliable calibrated age ranges when the regional marine reservoir correction is well-established. For mollusks from an estuarine environment the reservoir correction may be significantly different than the regional marine reservoir correction due to the input of bedrock or soil derived carbonates. Some mollusk species such as oysters are tolerant of a significant range of salinities which makes it difficult to determine which reservoir correction is appropriate. A case study is presented of an anomalous radiocarbon age for an oyster shell paint dish found in the fabric of the ruined nave walls of St Mary's Church, Shoreham-by-Sea, West Sussex, England. Stable isotopes (delta O-18 and delta C-13) were used to establish the type of environment in which the oyster had lived. Paired marine and terrestrial samples from a nearby medieval site were radiocarbon dated to provide an appropriate reservoir correction.